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Sample records for wave ultrasonic motor

  1. Transient Response Model of Standing Wave Piezoelectric Linear Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    SHI Yunlai; CHEN Chao; ZHAO Chunsheng

    2012-01-01

    A transient response model for describing the starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor was presented.Based on the contact dynamic model,the kinetic equation of the motor was derived.The starting and stopping characteristics of the standing wave piezoelectric linear ultrasonic motor according to different loads,contact stiffness and inertia mass were described and analyzed,respectively.To validate the transient response model,a standing wave piezoelectric linear ultrasonic motor based on in-plane modes was used to carry out the simulation and experimental study.The corresponding results showed that the simulation of the motor performances based on the proposed model agreed well with the experimental results.This model will helpful to improve the stepping characteristics and the control flexibility of the standing wave piezoelectric linear ultrasonic motor.

  2. Chaotic operation and chaos control of travelling wave ultrasonic motor.

    Science.gov (United States)

    Shi, Jingzhuo; Zhao, Fujie; Shen, Xiaoxi; Wang, Xiaojie

    2013-08-01

    The travelling wave ultrasonic motor, which is a nonlinear dynamic system, has complex chaotic phenomenon with some certain choices of system parameters and external inputs, and its chaotic characteristics have not been studied until now. In this paper, the preliminary study of the chaos phenomenon in ultrasonic motor driving system has been done. The experiment of speed closed-loop control is designed to obtain several groups of time sampling data sequence of the amplitude of driving voltage, and phase-space reconstruction is used to analyze the chaos characteristics of these time sequences. The largest Lyapunov index is calculated and the result is positive, which shows that the travelling wave ultrasonic motor has chaotic characteristics in a certain working condition Then, the nonlinear characteristics of travelling wave ultrasonic motor are analyzed which includes Lyapunov exponent map, the bifurcation diagram and the locus of voltage relative to speed based on the nonlinear chaos model of a travelling wave ultrasonic motor. After that, two kinds of adaptive delay feedback controllers are designed in this paper to control and suppress chaos in USM speed control system. Simulation results show that the method can control unstable periodic orbits, suppress chaos in USM control system. Proportion-delayed feedback controller was designed following and arithmetic of fuzzy logic was used to adaptively adjust the delay time online. Simulation results show that this method could fast and effectively change the chaos movement into periodic or fixed-point movement and make the system enter into stable state from chaos state. Finally the chaos behavior was controlled.

  3. Nonlinear dynamic analysis of traveling wave-type ultrasonic motors.

    Science.gov (United States)

    Nakagawa, Yosuke; Saito, Akira; Maeno, Takashi

    2008-03-01

    In this paper, nonlinear dynamic response of a traveling wave-type ultrasonic motor was investigated. In particular, understanding the transient dynamics of a bar-type ultrasonic motor, such as starting up and stopping, is of primary interest. First, the transient response of the bar-type ultrasonic motor at starting up and stopping was measured using a laser Doppler velocimeter, and its driving characteristics are discussed in detail. The motor is shown to possess amplitude-dependent nonlinearity that greatly influences the transient dynamics of the motor. Second, a dynamical model of the motor was constructed as a second-order nonlinear oscillator, which represents the dynamics of the piezoelectric ceramic, stator, and rotor. The model features nonlinearities caused by the frictional interface between the stator and the rotor, and cubic nonlinearity in the dynamics of the stator. Coulomb's friction model was employed for the interface model, and a stick-slip phenomenon is considered. Lastly, it was shown that the model is capable of representing the transient dynamics of the motor accurately. The critical parameters in the model were identified from measured results, and numerical simulations were conducted using the model with the identified parameters. Good agreement between the results of measurements and numerical simulations is observed.

  4. A standing wave-type noncontact linear ultrasonic motor.

    Science.gov (United States)

    Hu, J; Li, G; Chan, H L; Choy, C L

    2001-05-01

    In this study, a novel standing wave-type noncontact linear ultrasonic motor is proposed and analyzed. This linear ultrasonic motor uses a properly controlled ultrasonic standing wave to levitate and drive a slider. A prototype of the motor was constructed by using a wedge-shaped aluminum stator, which was placed horizontally and driven by a multilayer PZT vibrator. The levitation and motion of the slider were observed. Assuming that the driving force was generated by the turbulent acoustic streaming in the boundary air layer next to the bottom surface of the slider, a theoretical model was developed. The calculated characteristics of this motor were found to agree quite well with the experimental results. Based on the experimental and theoretical results, guidelines for increasing the displacement and speed of the slider were obtained. It was found that increasing the stator vibration displacement, or decreasing the gradient of the stator vibration velocity and the weight per unit area of the slider, led to an increase of the slider displacement. It was also found that increasing the amplitude and gradient of the stator vibration velocity, or decreasing the weight per unit area of the slider and the driving frequency, gave rise to an increase of the slider speed. There exists an optimum roughness of the bottom surface of the slider at which the slider speed has a maximum.

  5. Characteristics of ring type traveling wave ultrasonic motor in vacuum.

    Science.gov (United States)

    Qu, Jianjun; Zhou, Ningning; Tian, Xiu; Jin, Long; Xu, Zhike

    2009-03-01

    The characteristics of ultrasonic motor strongly depend on the properties of stator/rotor contact interface which are affected by ambient environment. With the developed apparatus, load properties of two ring type traveling wave ultrasonic motors in atmosphere, low vacuum and high vacuum were studied, respectively. Wear of friction material, variations of vacuum degree and the temperature of motor during the experiment were also measured. The results show that load properties of motor A in vacuum were poorer than those in atmosphere, when load torque M(f) was less than 0.55 N m. Compared to motor A, load properties of motor B were affected a little by environmental pressure. Wear of friction material in vacuum was more severe than wear in atmosphere. The temperature of motor in vacuum rose more quickly than it in atmosphere and had not reached equilibrium in 2 h experiment. However, the temperature of motor in atmosphere had reached equilibrium in about forth minutes. Furthermore, outgas was also observed during experiment under vacuum conditions.

  6. Contact Analysis and Modeling of Standing Wave Linear Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    SHI Yunlai; ZHAO Chunsheng; ZHANG Jianhui

    2011-01-01

    A contact model for describing the contact mechanics between the stator and slider of the standing wave linear ultrasonic motor was presented.The proposed model starts from the assumption that the vibration characteristics of the stator is not affected by the contact process.A modified friction models was used to analyze the contact problems.Firstly,the dynamic normal contact force,interface friction force,and steady-state characteristics were analyzed.Secondly,the influences of the contact layer material,the dynamic characteristics of the stator,and the pre-load on motor performance were simulated.Finally,to validate the contact model,a linear ultrasonic motor based on in-plane modes was used as an example.The corresponding results show that a set of simulation of motor performances based on the proposed contact mechanism is in good agreement with experimental results.This model is helpful to understanding the operation principle of the standing wave linear motor and thus contributes to the design of these tvpes of motor.

  7. Standing wave brass-PZT square tubular ultrasonic motor.

    Science.gov (United States)

    Park, Soonho; He, Siyuan

    2012-09-01

    This paper reports a standing wave brass-PZT tubular ultrasonic motor. The motor is composed of a brass square tube with two teeth on each tube end. Four PZT plates are attached to the outside walls of the brass tube. The motor requires only one driving signal to excite vibration in a single bending mode to generate reciprocating diagonal trajectories of teeth on the brass tube ends, which drive the motor to rotate. Bi-directional rotation is achieved by exciting different pairs of PZT plates to switch the bending vibration direction. Through using the brass-PZT tube structure, the motor can take high magnitude vibration to achieve a high output power in comparison to PZT tube based ultrasonic motors. Prototypes are fabricated and tested. The dimension of the brass-PZT tube is 3.975mm×3.975mm×16mm. Measured performance is a no-load speed of >1000RPM, a stall torque of 370μNm and a maximum output power of 16 mW when a sinusoidal driving voltage of 50V is applied. The working frequencies of the motor are 46,050Hz (clockwise) and 46,200Hz (counter-clockwise).

  8. A cylindrical standing wave ultrasonic motor using bending vibration transducer.

    Science.gov (United States)

    Liu, Yingxiang; Chen, Weishan; Liu, Junkao; Shi, Shengjun

    2011-07-01

    A cylindrical standing wave ultrasonic motor using bending vibration transducer was proposed in this paper. The proposed stator contains a cylinder and a bending vibration transducer. The two combining sites between the cylinder and the transducer locate at the adjacent wave loops of bending vibration of the transducer and have a distance that equal to the half wave length of bending standing wave excited in the cylinder. Thus, the bending mode of the cylinder can be excited by the bending vibration of the transducer. Two circular cone type rotors are pressed in contact to the end rims of the teeth, and the preload between the rotors and stator is accomplished by a spring and nut system. The working principle of the proposed motor was analyzed. The motion trajectories of teeth were deduced. The stator was designed and analyzed with FEM. A prototype motor was fabricated and measured. Typical output of the prototype is no-load speed of 165rpm and maximum torque of 0.45Nm at an exciting voltage of 200V(rms).

  9. Contact analysis and mathematical modeling of traveling wave ultrasonic motors.

    Science.gov (United States)

    Zhu, Meiling

    2004-06-01

    An analysis of the contact layer and a mathematical modeling of traveling wave ultrasonic motors (TWUM) are presented for the guidance of the design of contact layer and the analyses of the influence of the compressive force and contact layer on motor performance. The proposed model starts from a model previously studied but differs from that model in that it adds the analysis of the contact layer and derives the steady-state solutions of the nonlinear equations in the frequency domain, rather than in the time domain, for the analyses of vibrational responses of the stator and operational characteristics of the motor. The maximum permissible compressive force of the motor, the influences of the contact layer material, the thickness of the contact layer, and the compressive force on motor performance have been discussed. The results show that by using the model, one can understand the influence of the compressive force and contact layer material on motor performance, guide the choice of proper contact layer material, and calculate the maximum permissible compressive force and starting voltage.

  10. Traveling wave ultrasonic motor using polymer-based vibrator

    Science.gov (United States)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-01-01

    With the characteristics of low density, low elastic modulus, and low mechanical loss, poly(phenylene sulfide) (PPS) is a promising material for fabricating lightweight ultrasonic motors (USMs). For the first time, we used PPS to fabricate an annular elastomer with teeth and glued a piece of piezoelectric-ceramic annular disk to the bottom of the elastomer to form a vibrator. To explore for a material suitable for the rotor surface coming in contact with the PPS-based vibrator, several disk-shaped rotors made of different materials were fabricated to form traveling wave USMs. The polymer-based USM rotates successfully as the conventional metal-based USMs. The experimental results show that the USM with the aluminum rotor has the largest torque, which indicates that aluminum is the most suitable for the rotor surface among the tested materials.

  11. Ultrasonic Motors

    Science.gov (United States)

    2003-06-01

    and T. Higuchi, "Cylindrical Micro Ultrasonic Motor Utilizing Bulk Lead Zirconate Titanate (PZT)," Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers, vol. 38, pp. 3347-3350, 1999.

  12. Actuating Mechanism and Design of a Cylindrical Traveling Wave Ultrasonic Motor Using Cantilever Type Composite Transducer

    OpenAIRE

    Yingxiang Liu; Weishan Chen; Junkao Liu; Shengjun Shi

    2010-01-01

    BACKGROUND: Ultrasonic motors (USM) are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. USM exhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher position accuracy. PRINCIPAL FINDINGS: A cylindrical type traveling wave ultrasonic motor using cantilever type composite transducer was proposed in this paper. There are two cantilevers on the ...

  13. A New Scheme for Experimental-Based Modeling of a Traveling Wave Ultrasonic Motor

    DEFF Research Database (Denmark)

    Mojallali, Hamed; Amini, R.; Izadi-Zamanabadi, Roozbeh

    2005-01-01

    In this paper, a new method for equivalent circuit modeling of a traveling wave ultrasonic motor is presented. The free stator of the motor is modeled by an equivalent circuit containing complex circuit elements. A systematic approach for identifying the elements of the equivalent circuit...

  14. A Novel Traveling Wave Ultrasonic Motor Using a Bar Shaped Transducer

    Institute of Scientific and Technical Information of China (English)

    JIN Jiamei; ZHAO Chunsheng

    2008-01-01

    A novel traveling wave ultrasonic motor was proposed.The structure of the motor is rather simple and different from the conventional traveling wave ultra.sonic motors.Its production processes are very convenient.It is composed of a stator constituted with a ring and a bar shaped transducer and two cone shaped rotors.The rotors were pressed on inner surface of the ring by means of a pre-pressure system.The bar shaped transducer has a sandwich-like configuration,where two sets of piezoelectric element are bolted.One set excites a longitudinal vibration of the bar,and the other set excites a flexural vibration of the bar.The ring's traveling wave excited with the longitudinal vibration and the bending vibration of the bar transducer was simulated with FEM (finite element method).The prototype of the motor was made and investigated experimentally for its performance.Its maximum torque and ro

  15. Analyses of the temperature field of traveling-wave rotary ultrasonic motors.

    Science.gov (United States)

    Lu, Xiaolong; Hu, Junhui; Zhao, Chunsheng

    2011-12-01

    In this paper, the transient and steady-state temperature field of a traveling-wave rotary ultrasonic motor is analyzed by the finite element method, based on a theoretical model of power loss of this motor in rated operation. Using this model, the temperature field of this motor is calculated and the effects of the heat conductivity of friction material, motor size, ambient temperature, and pressure on the temperature field are estimated. The calculated temperature distribution and transient temperature change agree with the experimental results. The variation of heat conductivity of the friction material has little effect on the minimum temperature in the motor but this variation seriously affects the maximum temperature in the motor when the heat conductivity of the friction material is lower than 0.5 W/(m°C). Two indices are defined to express the non-uniformity of temperature field and how quickly the temperature field reaches its steady state for traveling-wave ultrasonic motors of different sizes. It is found that traveling-wave ultrasonic motors with different sizes have different nonuniformity of temperature field and take different amounts of time to reach thermal steady state. The maximum temperature rise is lower when the ambient temperature is higher; the maximum temperature increases as the vacuum degree increases and it is not affected by the vacuum degree when the vacuum degree is too high (<10(-3) Pa).

  16. A rod type linear ultrasonic motor utilizing longitudinal traveling waves: proof of concept

    Science.gov (United States)

    Wang, Liang; Wielert, Tim; Twiefel, Jens; Jin, Jiamei; Wallaschek, Jörg

    2017-08-01

    This paper proposes a non-resonant linear ultrasonic motor utilizing longitudinal traveling waves. The longitudinal traveling waves in the rod type stator are generated by inducing longitudinal vibrations at one end of the waveguide and eliminating reflections at the opposite end by a passive damper. Considering the Poisson’s effect, the stator surface points move on elliptic trajectories and the slider is driven forward by friction. In contrast to many other flexural traveling wave linear ultrasonic motors, the driving direction of the proposed motor is identical to the wave propagation direction. The feasibility of the motor concept is demonstrated theoretically and experimentally. First, the design and operation principle of the motor are presented in detail. Then, the stator is modeled utilizing the transfer matrix method and verified by experimental studies. In addition, experimental parameter studies are carried out to identify the motor characteristics. Finally, the performance of the proposed motor is investigated. Overall, the results indicate very dynamic drive characteristics. The motor prototype achieves a maximum mean velocity of 115 mm s-1 and a maximum load of 0.25 N. Thereby, the start-up and shutdown times from the maximum speed are lower than 5 ms.

  17. Desing And Implementation Of A Digitally Controlled Compact Speed Driver For Travelling Wave Ultrasonic Motor

    OpenAIRE

    Altan Gencer

    2013-01-01

    In this paper, a compact size digitally controlled speed driver for travelling wave ultrasonic motor was designed and implemented. Although the driver system is light in weight, simple, small in size, it is possible to enter speed and direction digitally as well as tracking the real motor speed, voltage and current on an LCD. The implemented system was tested in a laboratory for different speed and load cases and obtained results are presented.

  18. Desing And Implementation Of A Digitally Controlled Compact Speed Driver For Travelling Wave Ultrasonic Motor

    Directory of Open Access Journals (Sweden)

    Altan Gencer

    2013-05-01

    Full Text Available In this paper, a compact size digitally controlled speed driver for travelling wave ultrasonic motor was designed and implemented. Although the driver system is light in weight, simple, small in size, it is possible to enter speed and direction digitally as well as tracking the real motor speed, voltage and current on an LCD. The implemented system was tested in a laboratory for different speed and load cases and obtained results are presented.

  19. A new visco-elastic contact model of traveling wave ultrasonic motor with stator frictional layer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new contact model of traveling wave ultrasonic motor (TWUSM) with a visco-elastic stator frictional layer was presented. In this model, the initial boundaries were revised, and the rotor revolution speed could be calculated iteratively. This model was compared with compliant slider and rigid stator model. The results of motor characteristics simulations showed that the motors based on this model would gain bigger stall torque. Then the friction and wear characteristics of two models were analyzed. The motors based on this model had lower coefficient of friction and better wear resistance.

  20. Research on resonance and antiresonance states of free stator of traveling wave ultrasonic motors

    Institute of Scientific and Technical Information of China (English)

    ZU Jiakui; ZHAO Chunsheng

    2004-01-01

    Under the condition of high-power drive, the experimental phenomena of free stator of traveling wave ultrasonic motor takes on strong nonlinear effects. Firstly, its corresponding theories are established to analyze and compare the stator's performances at the resonance and antiresonance states. At the same time, some important parameters, such as resonance/antiresonance frequency, mechanical quality, electro-mechanic coupling, and the relative vibration effect, are selected elaborately to evaluate the vibrational performances of free stator. Then, some experimental schemes based on the laser vibration measurement are designed respectively. Under the different drives conditions, the experimental characterizations of free stator at the resonance and antiresonance states are analyzed systematically. Finally, The investigative results show that the performance at the antiresonance state is much better than that at the resonance state. Some conclusions of this paper can provide novel idea and guidance for the choosing of the operating states and driving modes of traveling wave ultrasonic motor.

  1. Modeling stick-slip-separation dynamics in a bimodal standing wave ultrasonic motor

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; Lv, Qibao; Liu, Zhen

    2016-11-01

    Ultrasonic motor (USM) is an electromechanical coupling system with ultrasonic vibration, which is driven by the frictional contact force between the stator (vibrating body) and the rotor/slider (driven body). Stick-slip motion can occur at the contact interface when USM is operating, which may affect the performance of the motor. This paper develops a physically-based model to investigate the complex stick-slip-separation dynamics in a bimodal standing wave ultrasonic motor. The model includes both friction nonlinearity and intermittent separation nonlinearity of the system. Utilizing Hamilton's principle and assumed mode method, the dynamic equations of the stator are deduced. Based on the dynamics of the stator and the slider, sticking force during the stick phase is derived, which is used to examine the stick-to-slip transition. Furthermore, the stick-slip-separation kinematics is analyzed by establishing analytical criteria that predict the transition between stick, slip and separation of the interface. Stick-slip-separation motion is observed in the resulting model, and numerical simulations are performed to study the influence of parameters on the range of possible motions. Results show that stick-slip motion can occur with greater preload and smaller voltage amplitude. Furthermore, a dimensionless parameter is proposed to predict the occurrence of stick-slip versus slip-separation motions, and its role in designing ultrasonic motors is discussed. It is shown that slip-separation motion is favorable for the slider velocity.

  2. Improved linear ultrasonic motor performance with square-wave based driving-tip trajectory

    Science.gov (United States)

    Le, Adam Y.; Mills, James K.; Benhabib, Beno

    2015-03-01

    This paper proposes the application of a non-sinusoidal periodic excitation voltage to induce a near-square-wave driving tip trajectory in linear ultrasonic motors (LUSMs). A square-wave-based trajectory can deliver superior frictional force to the moving stage in the forward stroke of the driving tip motion and reduced frictional force during the return stroke. This would reduce lost power in the periodic driving tip motion, thereby, increasing the output force and power of the LUSM. An implementation procedure is suggested to achieve the near-square-wave driving tip trajectory. The proposed approach is illustrated through realistic finite-element-based simulations using a bimodal LUSM configuration.

  3. Free Stator Modeling of a Traveling Wave Ultrasonic Motor

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh; Helbo, Jan; Mojallali, Hamed

    2005-01-01

    An equivalent circuit method describing the free stator of piezoelectric motor is presented in this paper, while the circuit elements have complex values. The mechanical, dielectric and piezoelectric losses associated with the vibrator are accounted for by the imaginary components of the circuit ...

  4. A new traveling wave ultrasonic motor using thick ring stator with nested PZT excitation.

    Science.gov (United States)

    Chen, Weishan; Shi, Shengjun; Liu, Yingxiang; Li, Pei

    2010-05-01

    To avoid the disadvantages of conventional traveling wave ultrasonic motors--lower efficiency PZT working mode of d(31), fragility of the PZT element under strong excitation, fatigue of the adhesive layer under harsh environmental conditions, and low volume of the PZT material in the stator--a new type of traveling wave ultrasonic motor is presented in this paper. Here we implement the stator by nesting 64 PZT stacks in 64 slots specifically cut in a thick metal ring and 64 block springs nested within another 64 slots to produce preloading on the PZT stacks. In this new design, the d33 mode of the PZT is used to excite the flexural vibrations of the stator, and fragility of the PZT ceramics and fatigue of the adhesive layer are no longer an issue. The working principle, FEM simulation, fabrication, and performance measurements of a prototype motor were demonstrated to validate the proposed ideas. Typical output of the prototype motor is no-load speed of 15 rpm and maximum torque of 7.96 N x m. Further improvement will potentially enhance its features by increasing the accuracy in fabrication and adopting appropriate frictional material into the interface between the stator and the rotor.

  5. Actuating mechanism and design of a cylindrical traveling wave ultrasonic motor using cantilever type composite transducer.

    Directory of Open Access Journals (Sweden)

    Yingxiang Liu

    Full Text Available BACKGROUND: Ultrasonic motors (USM are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. USM exhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher position accuracy. PRINCIPAL FINDINGS: A cylindrical type traveling wave ultrasonic motor using cantilever type composite transducer was proposed in this paper. There are two cantilevers on the outside surface of cylinder, four longitudinal PZT ceramics are set between the cantilevers, and four bending PZT ceramics are set on each outside surface of cantilevers. Two degenerate flexural vibration modes spatially and temporally orthogonal to each other in the cylinder are excited by the composite transducer. In this new design, a single transducer can excite a flexural traveling wave in the cylinder. Thus, elliptical motions are achieved on the teeth. The actuating mechanism of proposed motor was analyzed. The stator was designed with FEM. The two vibration modes of stator were degenerated. Transient analysis was developed to gain the vibration characteristic of stator, and results indicate the motion trajectories of nodes on the teeth are nearly ellipses. CONCLUSIONS: The study results verify the feasibility of the proposed design. The wave excited in the cylinder isn't an ideal traveling wave, and the vibration amplitudes are inconsistent. The distortion of traveling wave is generated by the deformation of bending vibration mode of cylinder, which is caused by the coupling effect between the cylinder and transducer. Analysis results also prove that the objective motions of nodes on the teeth are three-dimensional vibrations. But, the vibration in axial direction is minute compared with the vibrations in circumferential and radial direction. The results of this paper can guide the development of this new type of motor.

  6. A cylindrical traveling wave ultrasonic motor using a circumferential composite transducer.

    Science.gov (United States)

    Liu, Yingxiang; Liu, Junkao; Chen, Weishan

    2011-11-01

    This paper intends to present and verify a new idea for constructing traveling wave ultrasonic motors that may effectively avoid the drawbacks of conventional traveling wave motors using bonded PZT plates as the exciting elements. In the configuration of the motor's stator, a composite sandwich type transducer is used to excite a traveling wave in a cylinder with two cantilevers as the coupling bridges between the transducer and the cylinder. The design process of the stator is described using the FEM modal analysis method, and the establishment of traveling wave on the cylindrical stator was simulated by FEM transient analysis. To verify the theoretical analysis results, a laser Doppler scanner was employed to test the mode shapes of a prototype stator excited by the longitudinal and bending vibrations respectively. Finally, to validate the design idea, a prototype motor was fabricated and tested; the typical output features are no-load speed of 156 rpm and maximum torque of 0.75 N·m under exciting voltages of 70 V(rms) applied to excite the longitudinal vibration of the transducer and 200 V(rms) applied to excite the bending vibration.

  7. Novel modeling technique for the stator of traveling wave ultrasonic motors.

    Science.gov (United States)

    Pons, José L; Rodríguez, Humberto; Ceres, Ramón; Calderón, Leopoldo

    2003-11-01

    Traveling wave ultrasonic motors (TWUM) are a promising type of piezoelectric transducers, which are based on the friction transmission of mechanical propagating waves. These waves are excited on the stator by using high Q piezoelectric ceramics. This article presents a modeling strategy, which allows for a quick and precise modal and forced analysis of the stator of TWUM. First-order shear deformation laminated plate theory is applied to annular subdomains (super-elements) of the stator. In addition to shear deformations, the model takes into account the effect of rotary inertia, the stiffness contribution of the teeth, and the linear varying thickness of the stator. Moreover, the formulation considers a more realistic function for the electric field inside the piezoelectric ceramic, i.e., a linear function, instead of the generally assumed constant electric field. The Ritz method is used to find an approximated solution for the dynamic equations. Finally, the modal response is obtained and compared against the results from classical simplified models and the finite element method. Thus, the high accuracy and short computation times of the novel strategy were demonstrated.

  8. Introduction to ultrasonic motors

    Energy Technology Data Exchange (ETDEWEB)

    Sashida, Toshiiku; Kenjo, Takashi.

    1993-01-01

    The ultrasonic motor, invented in 1980, utilizes the piezoelectric effect in the ultrasonic frequency range to provide the motive force. (In conventional electric motors the motive force is electromagnetic.) The result is a motor with unusually good low-speed high-torque and power-to-weight characteristics. It has already found applications in camera autofocus mechanisms, medical equipment subject to high magnetic fields, and motorized car accessories. Its applications will increase as designers become more familiar with its unique characteristics. This book is the result of a collaboration between the inventor and an expert in conventional electric motors: the result is an introduction to the general theory presented in a way that links it to conventional motor theory. It will be invaluable both to motor designers and to those who design with and use electric motors as an introduction to this important new invention.

  9. The effect of friction reduction in presence of ultrasonic vibrations and its relevance to travelling wave ultrasonic motors.

    Science.gov (United States)

    Storck, H; Littmann, W; Wallaschek, J; Mracek, M

    2002-05-01

    In many ultrasonic applications frictional effects play an important role (e.g. ultrasonic machining, ultrasonic motors). For optimising the applications in terms of quality, efficiency and lifetime it is important to understand the frictional coupling of the vibrating and the non-vibrating part. This contribution is devoted to give an explanation for the reduction of friction forces which is often observed when ultrasonic vibrations are superimposed to macroscopic motions. Usually adopted coefficients of friction are used for modelling such conditions suggesting special frictional mechanisms for high frequency oscillations, whereas the present paper shows that Coulomb's friction law provides a very good description of the observed phenomena if the kinematics of the system is taken into account. Two systems are investigated. In the first system the ultrasonic and macroscopic movements are parallel and in the second they are perpendicular to each other but also within the plane of contact. Both systems were investigated analytically and experimentally using a specially designed test rig. The measurements confirmed the analytically derived equations and therefore the validity of Coulomb's friction law even for ultrasonic conditions.

  10. A finite volume method and experimental study of a stator of a piezoelectric traveling wave rotary ultrasonic motor.

    Science.gov (United States)

    Bolborici, V; Dawson, F P; Pugh, M C

    2014-03-01

    Piezoelectric traveling wave rotary ultrasonic motors are motors that generate torque by using the friction force between a piezoelectric composite ring (or disk-shaped stator) and a metallic ring (or disk-shaped rotor) when a traveling wave is excited in the stator. The motor speed is proportional to the amplitude of the traveling wave and, in order to obtain large amplitudes, the stator is excited at frequencies close to its resonance frequency. This paper presents a non-empirical partial differential equations model for the stator, which is discretized using the finite volume method. The fundamental frequency of the discretized model is computed and compared to the experimentally-measured operating frequency of the stator of Shinsei USR60 piezoelectric motor.

  11. A novel two-degree-of-freedom spherical ultrasonic motor using three travelling-wave type annular stators

    Institute of Scientific and Technical Information of China (English)

    王剑; 胡锡幸; 王班; 郭吉丰

    2015-01-01

    In order to promote the tolerance and controllability of the multi-degree-of-freedom (M-DOF) ultrasonic motor, a novel two-degree-of-freedom (2-DOF) spherical ultrasonic motor using three traveling-wave type annular stators was put forward. Firstly, the structure and working principle of this motor were introduced, especially a spiral spring as the preload applied component was designed for adaptive adjustment. Then, the friction drive model of 2-DOF spherical motor was built up from spatial geometric relation between three annular stators and the spherical rotor which was used to analyze the mechanical characteristics of the motor. The optimal control strategy for minimum norm solution of three stators’ angular velocity was proposed, using Moore-Penrose generalized inverse matrix. Finally, a 2-DOF prototype was fabricated and tested, which ran stably and controllably. The maximum no-load velocity and stall torque are 92 r/min and 90 mN·m, respectively. The 2-DOF spherical ultrasonic motor has compact structure, easy assembly, good performance and stable operation.

  12. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  13. 行波超声波电动机混沌建模与分析%Chaos Modeling and Analysis of Traveling Wave Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    李文娟; 史敬灼

    2012-01-01

    作为一个复杂的非线性动力学系统,在一定的参数范围和外部输入条件下,行波超声波电动机系统存在复杂的混沌运动,但至今未见相关研究.在建立行波超声波电动机非线性混沌分析模型基础上,分析行波超声波电动机转速控制系统的Lyapunov指数谱、分岔图及电压相对于转速的轨迹图等非线性运行特性,为超声波电动机的混沌控制及反控制研究奠定了基础.%The traveling wave ultrasonic motor, which is a nonlinear dynamic system, can exhibit a variety of chaotic phenomenon under some choices of system parameters and external inputs, and its chaotic characteristics have not been studied until now. Based on the non-linear chaos model of a traveling wave ultrasonic motor, its nonlinear characteristics were analyzed with respect to the bifurcation diagram, Lyapunov exponent map and the locus of voltage relative to speed. The results show that the traveling wave ultrasonic motor has chaos characteristic under certain working condition. The theoretic foundation was established for the control and anti-control of chaos in traveling wave ultrasonic motor.

  14. Bi-modes alternation stepping ultrasonic motors

    Institute of Scientific and Technical Information of China (English)

    Jiamei JIN; Chunsheng ZHAO

    2008-01-01

    Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry. The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement of the motor is 2.5°.

  15. Ultrasonic Linear Motor with Anisotropic Composite

    Institute of Scientific and Technical Information of China (English)

    曾周末; 王新辉; 赵伯雷

    2004-01-01

    An idea to make up the vibrating body of ultrasonic motor with anisotropic composite is proposed and a linear piezoelectric motor is developed in this paper. Relative problems such as actuating mechanism, resonant frequency are discussed theoretically. According to the feature that impulse exists between the elastic body of composite ultrasonic linear motor and the base, an impulse analysis is presented to calculate the motor′s friction driving force and frictional conversion efficiency. The impulse analysis essentially explains the reason why the ultrasonic motor has great driving force, and can be applied to analyze the non-linear ultrasonic motor.

  16. Systematic experimental based modeling of a rotary piezoelectric ultrasonic motor

    DEFF Research Database (Denmark)

    Mojallali, Hamed; Amini, Rouzbeh; Izadi-Zamanabadi, Roozbeh

    2007-01-01

    In this paper, a new method for equivalent circuit modeling of a traveling wave ultrasonic motor is presented. The free stator of the motor is modeled by an equivalent circuit containing complex circuit elements. A systematic approach for identifying the elements of the equivalent circuit...

  17. FINITE ELEMENT MODELLING OF AN ULTRASONIC ROTARY MOTOR

    Directory of Open Access Journals (Sweden)

    OANA CHIVU

    2014-05-01

    Full Text Available This paper tackles the use of ultrasonic motors with three degrees of freedom in view of various applications. In nanotechnology, due to their high precision values, fast speeds and response, the piezo positioning systems have become a key component in nano printing, nano production, nano assembling, high density data acquisition etc. The present paper deals with an in-depth final element analysis of the piezoceramic and turret disk of the ultrasonic rotary motor. Hence, the variation of nodal displacements for two driving values of the. Electrodes and the angular velocity in time will be illustrated. Moreover, the research renders the frequencies of the piezoelements and ultrasonic motor drive systems according to the travelling wave and various nodal displacements.

  18. Ultrasonic motors using piezoelectric ceramic multimode vibrators.

    Science.gov (United States)

    Takano, T; Tomikawa, Y; Ogasawara, T; Sugawara, S; Konno, M

    1990-01-01

    The development is reported of an ultrasonic motor using piezoelectric ceramic multimode vibrators consisting of circular or annular plates in which degenerate horizontal vibration modes of the same or different form are used. Two orthogonal nonaxisymmetric vibration modes were used in the same-form case, and the combination of a nonaxisymmetric vibration mode and a radial vibration mode was used in the different-forms case. Some details of the motor design and its experimental characteristics are presented. The ultrasonic motor presented here has a special advantage in its thin construction.

  19. Modeling and optimization of ultrasonic linear motors

    OpenAIRE

    Fernandez Lopez, José; Perriard, Yves

    2007-01-01

    Ultrasonic motors have received much attention these last years, in particular with regard to their modeling and their design principle. Their operating principle is based on piezoelectric ceramics that convert electrical energy into mechanical energy in the form of vibrations of an elastic body whose surface points perform an elliptic motion with a frequency in the ultrasonic range (≥ 20 kHz). The moving part, which is pressed against the vibrating body by a prestressing force, can move than...

  20. Model-Based Torque Control of Piezoelectric Ultrasonic Motors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Piezoelectric ultrasonic motors (PUMs) are ideal actuators for a variety of spaced-based robotics applications. These motors replace conventional drive systems...

  1. Lamb Wave Multitouch Ultrasonic Touchscreen.

    Science.gov (United States)

    Firouzi, Kamyar; Nikoozadeh, Amin; Carver, Thomas E; Khuri-Yakub, Butrus Pierre T

    2016-12-01

    Touchscreen sensors are widely used in many devices such as smart phones, tablets, and laptops with diverse applications. We present the design, analysis, and implementation of an ultrasonic touchscreen system that utilizes the interaction of transient Lamb waves with objects in contact with the screen. It attempts to improve on the existing ultrasound technologies, with the potential of addressing some of the weaknesses of the dominant technologies, such as the capacitive or resistive ones. Compared with the existing ultrasonic and acoustic modalities, among other advantages, it provides the capability of detecting several simultaneous touch points and also a more robust performance. The localization algorithm, given the hardware design, can detect several touch points with a very limited number of measurements (one or two). This in turn can significantly reduce the manufacturing cost.

  2. Experimental development of an ultrasonic linear motor

    CSIR Research Space (South Africa)

    M'Boungui, G

    2010-01-01

    Full Text Available The authors investigate a novel ultrasonic motor which generates a stator trajectory in the form of a figure-of-eight by superimposing two resonant modes, with one double the frequency of the other. Topology optimization was used to design...

  3. Same phase drive-type ultrasonic motors using two degenerate bending vibration modes of a disk.

    Science.gov (United States)

    Takano, T; Tomikawa, Y; Kusakabe, C

    1992-01-01

    Same-phase drive-type ultrasonic motors, using two degenerate bending vibration modes of a disk, are presented. The distinctive feature of the motor is in using the standing wave modes. The motor is not driven by two input signals with different phases, but by input signals with the same phase. Therefore, only one amplifier is sufficient to drive the motor. The experimental results have proved that the motor can yield stable operational characteristics at low speed and high torque.

  4. Finite element modelling of a rotating piezoelectric ultrasonic motor.

    Science.gov (United States)

    Frangi, A; Corigliano, A; Binci, M; Faure, P

    2005-10-01

    The evaluation of the performance of ultrasonic motors as a function of input parameters such as the driving frequency, voltage input and pre-load on the rotor is of key importance to their development and is here addressed by means of a finite element three-dimensional model. First the stator is simulated as a fully deformable elastic body and the travelling wave dynamics is accurately reproduced; secondly the interaction through contact between the stator and the rotor is accounted for by assuming that the rotor behaves as a rigid surface. Numerical results for the whole motor are finally compared to available experimental data.

  5. 基于UCC3895的行波型超声波电机驱动器设计%Design of traveling wave rotary ultrasonic motor driver based on UCC3895

    Institute of Scientific and Technical Information of China (English)

    宋人权; 王剑; 郭吉丰

    2012-01-01

    Previous ultrasonic motor driver based on non-intelligent chip is limited by its disadvantage of complex circuit and difficult phase-modulation. Aiming at this problem, the basic principle and characteristics of traveling wave type ultrasonic motor driver was introduced. According to the requirement of ultrasonic motor driven signal,a multi-function adjustable traveling wave type ultrasonic motor driver was designed based on BiCMOS advanced phase shift pulse width modulation(PWM) controller UCC3895. The relevant circuits and experiment waveforms were also provided. Experimental results verify the feasibility of design.%以往的基于非智能芯片的超声波电机驱动器往往存在电路复杂,调相困难等不足,因而限制了其使用范围.针对这一问题,首先简要介绍了行波型超声波电机驱动电路基本原理和性能要求;在比较以往驱动器优缺点的基础上提出了一种基于UUC3895的多功能可调节的行波型超声波电机驱动器,该驱动器基于BiCMOS相移谐振脉宽调制(PWM)控制原理,具有调频、调压和调相功能,并可扩展外部控制器;最后,给出了实验数据与波形图.实验结果验证了该设计的可行性.

  6. Design of motion adjusting system for space camera based on ultrasonic motor

    Science.gov (United States)

    Xu, Kai; Jin, Guang; Gu, Song; Yan, Yong; Sun, Zhiyuan

    2011-08-01

    Drift angle is a transverse intersection angle of vector of image motion of the space camera. Adjusting the angle could reduce the influence on image quality. Ultrasonic motor (USM) is a new type of actuator using ultrasonic wave stimulated by piezoelectric ceramics. They have many advantages in comparison with conventional electromagnetic motors. In this paper, some improvement was designed for control system of drift adjusting mechanism. Based on ultrasonic motor T-60 was designed the drift adjusting system, which is composed of the drift adjusting mechanical frame, the ultrasonic motor, the driver of Ultrasonic Motor, the photoelectric encoder and the drift adjusting controller. The TMS320F28335 DSP was adopted as the calculation and control processor, photoelectric encoder was used as sensor of position closed loop system and the voltage driving circuit designed as generator of ultrasonic wave. It was built the mathematic model of drive circuit of the ultrasonic motor T-60 using matlab modules. In order to verify the validity of the drift adjusting system, was introduced the source of the disturbance, and made simulation analysis. It designed the control systems of motor drive for drift adjusting system with the improved PID control. The drift angle adjusting system has such advantages as the small space, simple configuration, high position control precision, fine repeatability, self locking property and low powers. It showed that the system could accomplish the mission of drift angle adjusting excellent.

  7. Performance and Applications of L1B2 Ultrasonic Motors

    Directory of Open Access Journals (Sweden)

    Gal Peled

    2016-06-01

    Full Text Available Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operational robustness. This paper reviews the design of high precision motion solutions based on L1B2 ultrasonic motors—from the basic motor structure to the complete motion solution architecture, including motor drive and control, material considerations and performance envelope. The performance is demonstrated, via constructed motion stages, to exhibit fast move and settle, a repeatability window of tens of nanometers, lifetime into the tens of millions of operational cycles, and compatibility with clean room and aerospace environments. Example stages and modules for semiconductor, aerospace, electro-optical and biomedical applications are presented. The described semiconductor and aerospace solutions are powered by Nanomotion HR type motors, driven by a sine wave up to 80 V/mm rms, having a driving frequency of 39.6 kHz, providing a maximum force up to 4 N per driving element (at 5 W power consumption per element and a maximum linear velocity above 300 mm/s. The described electro-optical modules are powered by small Nanomotion Edge motors driven by voltages up to 11 V AC, providing stall forces up to 0.35 N (power consumption up to 0.75 W and maximum linear velocity above 200 mm/s.

  8. Fundamentals and Applications of Ultrasonic Waves

    CERN Document Server

    Cheeke, J David N

    2012-01-01

    Designed specifically for newcomers to the field, this fully updated second edition begins with fundamentals and quickly advances beyond general wave concepts into an in-depth treatment of ultrasonic waves in isotropic media. Focusing on the physics of acoustic waves, their propagation, technology, and applications, this accessible overview of ultrasonics includes accounts of viscoelasticity and multiple scattering. It examines new technologies, including atomic force acoustic microscopy, lasers, micro-acoustics, and nanotechnology. In addition, it highlights both direct and indirect applicati

  9. Linear ultrasonic motor using quadrate plate transducer

    Institute of Scientific and Technical Information of China (English)

    Jiamei JIN; Chunsheng ZHAO

    2009-01-01

    A linear ultrasonic motor using a quadrate plate transducer was developed for precision positioning. This motor consists of two pairs of Pb(Zr, Ti)O3 piezo-electric ceramic elements, which are piezoelectrically excited into the second-bending mode of the motor stator's neutral surface in two orthogonal directions, on which the tops of four projections move along an elliptical trajectory, which in turn drives a contacted slider into linear motion via frictional forces. The coincident frequency of the stator is easily obtained for its coincident characteristic dimen-sion in two orthogonal directions. The performance characteristics achieved by the motor are: 1) a maximum linear speed of more than 60 mm/s; 2) a stroke of more than 150 mm; 3) a driving force of more than 5.0 N; and 4) a response time of about 2 ms.

  10. Planar Rotary Piezoelectric Motor Using Ultrasonic Horns

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph; Geiyer, Daniel; Ostlund, Patrick N.; Allen, Phillip

    2011-01-01

    A motor involves a simple design that can be embedded into a plate structure by incorporating ultrasonic horn actuators into the plate. The piezoelectric material that is integrated into the horns is pre-stressed with flexures. Piezoelectric actuators are attractive for their ability to generate precision high strokes, torques, and forces while operating under relatively harsh conditions (temperatures at single-digit K to as high as 1,273 K). Electromagnetic motors (EM) typically have high rotational speed and low torque. In order to produce a useful torque, these motors are geared down to reduce the speed and increase the torque. This gearing adds mass and reduces the efficiency of the EM. Piezoelectric motors can be designed with high torques and lower speeds directly without the need for gears. Designs were developed for producing rotary motion based on the Barth concept of an ultrasonic horn driving a rotor. This idea was extended to a linear motor design by having the horns drive a slider. The unique feature of these motors is that they can be designed in a monolithic planar structure. The design is a unidirectional motor, which is driven by eight horn actuators, that rotates in the clockwise direction. There are two sets of flexures. The flexures around the piezoelectric material are pre-stress flexures and they pre-load the piezoelectric disks to maintain their being operated under compression when electric field is applied. The other set of flexures is a mounting flexure that attaches to the horn at the nodal point and can be designed to generate a normal force between the horn tip and the rotor so that to first order it operates independently and compensates for the wear between the horn and the rotor.

  11. Coupled tangential-axial resonant modes of piezoelectric hollow cylinders and their application in ultrasonic motors.

    Science.gov (United States)

    Vyshnevskyy, Oleksiy; Kovalev, Sergej; Mehner, Jan

    2005-01-01

    This paper describes a tangential-axial eigen-mode of a piezoelectric hollow cylinder. A new type of piezoelectric ultrasonic motor using this oscillation mode has been developed. The motor is a traveling-wave-type motor. The stator of such a motor consists of a solid piezoelectric hollow cylinder, which, excited in the tangential-axial resonant mode by a three-phase electrical signal, will exhibit elliptical displacement and transfer rotation to the rotor. The behavior of the stator has been simulated with finite element method (FEM) software. The simulation results have been checked with single-point contact measurements on the surface of the ultrasonic motors. The paper closes with the introduction of new ultrasonic motors based on this oscillation mode.

  12. Planar rotary motor using ultrasonic horns

    Science.gov (United States)

    Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Chang, Zensheu; Geiyer, Daniel; Allen, Phillip; Ostlund, Patrick; Bar-Cohen, Yoseph

    2011-04-01

    One of the first piezoelectric motor designs with significant rotational speeds was outlined by Barth. This device used extensional piezoelectric elements to produce a time varying force at a distance r from the center of a centrally supported disk. These extensional actuators produced micro-steps at a high frequency with the end result being macroscopic rotation of the disk and high torque. The rotation direction is controlled by the choice of the actuators and the direction of the extension about the rotor center. A recent advancement in producing pre-stressed power ultrasonic horns using flexures allows for the development of high torque ultrasonic motors based on the Barth's idea that can be fabricated in a 2D plate or in more complicated 3D structures. In addition to the pre-stress flexures the design also allows for the use of flexures to produce the rotor/horn normal force. The torque can be controlled by the number of actuators in the plane and the amplitude of the normal force. This paper will present analytical and experimental results obtained from testing prototype planar motors.

  13. Piezoelectric wave motor

    Science.gov (United States)

    Yerganian, Simon Scott

    2001-07-17

    A piezoelectric motor having a stator in which piezoelectric elements are contained in slots formed in the stator transverse to the desired wave motion. When an electric field is imposed on the elements, deformation of the elements imposes a force perpendicular to the sides of the slot, deforming the stator. Appropriate frequency and phase shifting of the electric field will produce a wave in the stator and motion in a rotor. In a preferred aspect, the piezoelectric elements are configured so that deformation of the elements in direction of an imposed electric field, generally referred to as the d.sub.33 direction, is utilized to produce wave motion in the stator. In a further aspect, the elements are compressed into the slots so as to minimize tensile stresses on the elements in use.

  14. Performance and Applications of L1B2 Ultrasonic Motors

    OpenAIRE

    Gal Peled; Roman Yasinov; Nir Karasikov

    2016-01-01

    Piezoelectric ultrasonic motors offer important advantages for motion applications where high speed is coupled with high precision. The advances made in the recent decades in the field of ultrasonic motor based motion solutions allow the construction of complete motion platforms in the fields of semiconductors, aerospace and electro-optics. Among the various motor designs, the L1B2 motor type has been successful in industrial applications, offering high precision, effective control and operat...

  15. Fundamentals and applications of ultrasonic waves

    CERN Document Server

    Cheeke, J David N

    2002-01-01

    Ultrasonics. A subject with applications across all the basic sciences, engineering, medicine, and oceanography, yet even the broader topic of acoustics is now rarely offered at undergraduate levels. Ultrasonics is addressed primarily at the doctoral level, and texts appropriate for beginning graduate students or newcomers to the field are virtually nonexistent.Fundamentals and Applications of Ultrasonic Waves fills that void. Designed specifically for senior undergraduates, beginning graduate students, and those just entering the field, it begins with the fundamentals, but goes well beyond th

  16. Synergetic driving concepts for bundled miniature ultrasonic linear motors.

    Science.gov (United States)

    Mracek, Maik; Hemsel, Tobias

    2006-12-22

    Rotary ultrasonic motors have found broad industrial application in camera lens drives and other systems. Linear ultrasonic motors in contrast have only found limited applications. The main reason for the limited range of application of these very attractive devices seems to be their small force and power range. Attempts to build linear ultrasonic motors for high forces and high power applications have not been truly successful yet. To achieve larger force and higher power, multiple miniaturized motors can be combined. This approach, however, is not as simple as it appears at first glance. The electromechanical behaviour of the individual motors differs slightly due to manufacturing and assembly tolerances. The individual motor characteristics are strongly dependent on the driving parameters (frequency, voltage, temperature, pre-stress, etc.) and the driven load and the collective behaviour of the swarm of motors is not just the linear superposition of the individual drive's forces. Thus, the bundle of motors has to be synchronized and controlled appropriately in order to obtain an optimized drive that is not oversized and costly. We have investigated driving and control strategies of a set of linear ultrasonic motors. Our contribution will be divided into three main parts. In part I ultrasonic linear motors will be introduced. In part II driving strategies for a single motor as well as for a bundle of motors will be presented. These concepts will be verified by simulation results and experimental data. In part III a simplified model for the motor's electromechanical behaviour will be given.

  17. Principle and experimental verification of novel dual driving face rotary ultrasonic motor

    Science.gov (United States)

    Lu, Xiaolong; Hu, Junhui; Yang, Lin; Zhao, Chunsheng

    2013-09-01

    Existing rotary ultrasonic motors operating in extreme environments cannot meet the requirements of good environmental adaptability and compact structure at same time, and existing ultrasonic motors with Langevin transducers show better environmental adaptability, but size of these motors are usually big due to the radial arrangement of the Langevin transducers. A novel dual driving face rotary ultrasonic motor is proposed, and its working principle is experimentally verified. The working principle of the novel ultrasonic motor is firstly proposed. The 5th in-plane flexural vibration travelling wave, excited by the Langevin transducers around the stator ring, is used to drive the rotors. Then the finite element method is used in the determination of dimensions of the prototype motor, and the confirmation of its working principle. After that, a laser Doppler vibrometer system is used for measuring the resonance frequency and vibration amplitude of the stator. At last, output characteristics of the prototype motor are measured, environmental adaptability is tested and performance for driving a metal ball is also investigated. At room temperature and 200 V(zero to peak) driving voltage, the motor’s no-load speed is 80 r/min, the stalling torque is 0.35 N·m and the maximum output power is 0.85 W. The response time of this motor is 0.96 ms at the room temperature, and it decreases or increases little in cold environment. A metal ball driven by the motor can rotate at 210 r/min with the driving voltage 300 V(zero to peak). Results indicate that the prototype motor has a large output torque and good environmental adaptability. A rotary ultrasonic motor owning compact structure and good environmental adaptability is proposed, and lays the foundations of ultrasonic motors’ applications in extreme environments.

  18. Absorption and dispersion of ultrasonic waves

    CERN Document Server

    Herzfeld, Karl F; Massey, H S W; Brueckner, Keith A

    1959-01-01

    Absorption and Dispersion of Ultrasonic Waves focuses on the influence of ultrasonics on molecular processes in liquids and gases, including hydrodynamics, energy exchange, and chemical reactions. The book first offers information on the Stokes-Navier equations of hydrodynamics, as well as equations of motion, viscosity, formal introduction of volume viscosity, and linearized wave equation for a nonviscous fluid. The manuscript then ponders on energy exchange between internal and external degrees of freedom as relaxation phenomenon; effect of slow energy exchange on sound propagation; differe

  19. Optimal working frequency of ultrasonic motors.

    Science.gov (United States)

    Shi, Weijia; Zhao, Hui; Ma, Jie; Yao, Yu

    2016-08-01

    In this work, the existence of the optimal working frequency for ultrasonic motors (USMs) is theoretically and experimentally verified for the first time, at which working point the power dissipation of the motors arrives at its minimum value. The mathematical model of the mechanical quality factor is initially deduced to evaluate the loss level, because it shows an opposite tendency with losses. The derivative of the mechanical quality factor can be subsequently arrived at with the aid of the phenomenon model of the phase of the admittance. The theoretical derivation infers that the maximum value of the mechanical quality factor exists almost around the average value of the frequency of maximum conductance and the frequency of maximum resistance. Then the input power of the USM is measured under the constant velocity condition, which is supposed to counteract the loss; that is, the loss can be therefore evaluated experimentally. Measurements infer that the power dissipation of the motor reaches the minimum value around the calculated optimal working frequency. In other word, it is proven that the USM maintains an optimal working frequency from the loss reduction view point.

  20. Meal assistance robot with ultrasonic motor

    Science.gov (United States)

    Kodani, Yasuhiro; Tanaka, Kanya; Wakasa, Yuji; Akashi, Takuya; Oka, Masato

    2007-12-01

    In this paper, we have constructed a robot that help people with disabilities of upper extremities and advanced stage amyotrophic lateral sclerosis (ALS) patients to eat with their residual abilities. Especially, many of people suffering from advanced stage ALS of the use a pacemaker. And they need to avoid electromagnetic waves. Therefore we adopt ultra sonic motor that does not generate electromagnetic waves as driving sources. Additionally we approach the problem of the conventional meal assistance robot. Moreover, we introduce the interface with eye movement so that extremities can also use our system. User operates our robot not with hands or foot but with eye movement.

  1. Ultrasonic motors with polymer-based vibrators.

    Science.gov (United States)

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2015-12-01

    With their characteristics of low density and elastic moduli, polymers are promising materials for making ultrasonic motors (USMs) with high energy density. Although it has been believed for a long time that polymers are too lossy to be applied to high-amplitude vibrators, there are several new polymers that exhibit excellent vibration characteristics. First, we measure the damping coefficients of some functional polymers to explore the applicability of polymers as vibrators for USMs. Second, to investigate the vibration characteristics, we fabricate bimorph vibrators using several kinds of polymers that have low attenuation. Third, a bending mode USM is fabricated with a polymer rod and four piezoelectric plates bonded on the rod as a typical example of a USM. Through an experimental investigation of the motor performance, it was found that the polymer-based USMs exhibited higher rotation velocity than the aluminum-based USM under a light preload, although the maximum torque of the polymer-based USMs was smaller than the aluminum-based USM. Among the tested polymers, polyphenylenesulfide was a prospective material for USMs under light preloads because of the high amplitude and lightweight of polyphenylenesulfide.

  2. Hand Gesture Recognition Using Ultrasonic Waves

    KAUST Repository

    AlSharif, Mohammed Hussain

    2016-04-01

    Gesturing is a natural way of communication between people and is used in our everyday conversations. Hand gesture recognition systems are used in many applications in a wide variety of fields, such as mobile phone applications, smart TVs, video gaming, etc. With the advances in human-computer interaction technology, gesture recognition is becoming an active research area. There are two types of devices to detect gestures; contact based devices and contactless devices. Using ultrasonic waves for determining gestures is one of the ways that is employed in contactless devices. Hand gesture recognition utilizing ultrasonic waves will be the focus of this thesis work. This thesis presents a new method for detecting and classifying a predefined set of hand gestures using a single ultrasonic transmitter and a single ultrasonic receiver. This method uses a linear frequency modulated ultrasonic signal. The ultrasonic signal is designed to meet the project requirements such as the update rate, the range of detection, etc. Also, it needs to overcome hardware limitations such as the limited output power, transmitter, and receiver bandwidth, etc. The method can be adapted to other hardware setups. Gestures are identified based on two main features; range estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized simple hardware setup was used to classify a set of hand gestures with high accuracy. The detection and classification were done using methods of low computational cost. This makes the proposed method to have a great potential for the implementation in many devices including laptops and mobile phones. The predefined set of gestures can be used for many control applications.

  3. Integration of a piezoelectric transformer and an ultrasonic motor.

    Science.gov (United States)

    Manuspiya, Suwan; Laoratanakul, Pitak; Uchino, Kenji

    2003-03-01

    Ultrasonic motors are usually operated at an AC voltage higher than a regular battery. This implies the need of a voltage step-up transformer. In this paper, we report the integration of a piezoelectric transformer (PT) with an ultrasonic motor and a simple drive circuit. The stator of the ultrasonic motor and the PT were operated in the same radial vibration mode. Their dimensions were very close to each other yielding nearly matching resonance frequencies. Consequently, they could be combined together without inductor. The drive circuit was designed by using a 555 timer as an astable multivibrator, and high-speed dual MOSFET drivers as a class D half-bridge switching amplifier. This integrated PT-ultrasonic motor performed reasonably without the use of electromagnetic transformer or inductor.

  4. Modelling of ultrasonic motor with dead-zone based on Hammerstein model structure

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The ultrasonic motor (USM) possesses heavy nonlinearities which vary with driving conditions and load-dependent characteristics such as the dead-zone. In this paper, an identification method for the rotary travelling-wave type ultrasonic motor (RTWUSM) with dead-zone is proposed based on a modified Hammerstein model structure. The driving voltage contributing effect on the nonlinearities of the RTWUSM was transformed to the change of dynamic parameters against the driving voltage.The dead-zone of the RTWUSM is identified based upon the above transformation. Experiment results showed good agreement between the output of the proposed model and actual measured output.

  5. A novel in-plane mode rotary ultrasonic motor

    Directory of Open Access Journals (Sweden)

    Lu Xiaolong

    2014-04-01

    Full Text Available Ultrasonic motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to the conventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings and bonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that the Langevin type transducer has excellent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improve the reliability of piezoelectric motors for space applications. In this study, a novel in-plane mode rotary ultrasonic motor is designed, fabricated, and characterized. The proposed motor operates in in-plane vibration mode which is excited by four Langevin-type bending vibrators separately placed around a ring-shaped stator. Two tapered rotors are assembled to the inner ring of the stator and clamped together by a screw nut. In order to make the motor more stable and convenient to fix, a thin cylindrical support is placed under the stator ring. Due to its no-bearing structure and Langevin transducer excitation, the prototype ultrasonic motor may operate well in aeronautic and astronautic environments.

  6. Development and study of novel non-contact ultrasonic motor based on principle of structural asymmetry.

    Science.gov (United States)

    Stepanenko, Dmitry A; Minchenya, Vladimir T

    2012-09-01

    The article presents novel design of non-contact rotary ultrasonic motor consisting of ring-shaped stator vibrating in in-plane flexural mode and rotor provided with blades. In contrast to other motors with similar design proposed motor relies on the use of standing ultrasonic waves. This simplifies design and electronic control of motor and becomes possible due to introduction of artificial asymmetry, for example by tilting one or several blades of the rotor relative to the surface normal. Operating principle of the proposed motor is based on acoustic radiation torque exerted on rotor by ultrasonic waves propagating in air or fluid gap between rotor and stator. This torque is calculated using finite element method by means of COMSOL Multiphysics software. Dynamics of rotor is studied using MathCad software and general theory of nonlinear conservative oscillators. Role of asymmetry is explained on the basis of comparative analysis of potential functions and phase trajectories for symmetric and asymmetric cases. It is shown that direction of rotation is determined by structural parameters of motor, particularly tilting direction (clockwise or counter-clockwise) of the blades. Conceptual design of motor with bidirectional rotation is described. Direction and velocity of rotation in the proposed conceptual design can be potentially controlled by changing excitation frequency of stator. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.

    2010-01-01

    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  8. Ultrasonic guided wave tomography for ice detection.

    Science.gov (United States)

    Zhao, Xiang; Rose, Joseph L

    2016-04-01

    Of great concern for many structures, particularly critical sections of rotary and fixed wing aircrafts, is the ability to detect ice either on grounded or in-flight vehicles. As a consequence, some work is reported here that could be useful for a variety of different industries where ice formation is an important problem. This paper presents experimental validations of a probability-based reconstruction algorithm (PRA) on ice detection of plate-like structures. The ice detection tests are performed for three different specimens: a single layer aluminum plate with a circular ice sensing array, a titanium plate with a sparse rectangular ice sensing array, and a carbon-fiber-reinforced titanium plate with an embedded ice sensing array mounted on a carbon fiber back plate. Cases from the simple to the more challenging exemplify that special modes can be used to differentiate ice from water, a sparse rectangular array could also be used for ice detection, and an ice sensing array could be further used to detect the ice on the sensor free side, a very useful application of ice sensing for aircraft wings, for example. Ice detection images for the respective cases are reconstructed to investigate the feasibility of ice sensing with ultrasonic guided wave tomography technology. The results show that the PRA based ultrasonic guided wave tomography method successfully detected and showed ice spots correctly for all three cases. This corroborates the fact that ultrasonic guided wave imaging technology could be a potential useful ice sensing tool in plate-like structures.

  9. Novel high torque bearingless two-sided rotary ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    LI Xia; CHEN Wei-shan; XIE Tao; LIU Jun-kao

    2007-01-01

    Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide sufficiently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting ora two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using experimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.

  10. Attenuation of ultrasonic waves in rolled metals

    Science.gov (United States)

    Yang, Liyong; Turner, Joseph A.

    2004-12-01

    Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave propagation and scattering model is formulated by the Dyson equation using an anisotropic Green's function approach. Within the limits of the first-order smoothing approximation, the Dyson equation is solved in the spatial Fourier transform domain. The results presented are shown to be directional dependent, frequency dependent, and especially dependent on the texture coefficients (ODCs) for the quasilongitudinal and two quasishear waves. The theoretical results presented may be used to improve the understanding of the microstructure during recrystallization processes. .

  11. 微型化矩形振子近似行波型直线超声波电动机%Quasi-Traveling Wave Ultrasonic Linear Motor Using a Miniature Rectangular Vibrator

    Institute of Scientific and Technical Information of China (English)

    张顺鑫; 李朝东

    2012-01-01

    With the aim of realizing quasi-traveling wave drive in ultrasonic linear micromotor, a novel quasi-traveling wave ultrasonic linear motor using a ring type rectangular vibrator with the size of 39 mmx6 mmxl2. 7 mm was proposed. Combined with the finite element modal analysis, the motor operating principle was described, that the traveling wave was excited and propagated along the ring type rectangular vibrator depending on the superposition of two orthogonal flexural-vi-bration modes with a spatial phase shift of 90 degrees. 7 piezoelectric ceramic elements were used to excite two working modes of the vibrator. In order to amplify the amplitude, the comb-tooth structure was designed in the bottom of the vibrator. The vibrator structure was designed and eigenfrequency degeneration was realized by Finite Element Analysis ( FEA) method. The modal test showed that the design scheme was tenable. The excitation and propagation of quasi-traveling wave was proved by tip rotation direction test. The trial motor gave a maximum driving velocity of 162. 5 mm/s and a maximum load of 8. 5 N,while the excitation frequency was 66 kHz and voltage peak-peak was 160 V. The motor can satisfy the preliminary design objective.%探索了在微型直线超声波电动机中实现近似行波驱动的途径,研制了一种外形尺寸为39 mm×6 mm×12.7 mm的环状矩形振子近似行波型直线超声波电动机.结合电机振子的有限元模态分析,阐述了依靠激发空间相位差为90°的两个正交弯曲振动模态,实现行波在环状矩形振子上被激发和传播的电机运动原理.使用7块压电陶瓷片来分别激发振子的两个工作模态.在振子底部设计了梳齿状结构,以放大振幅.利用有限元法进行结构设计,使两个工作模态的频率简并.通过激光测振,证实了电机振子设计方案的有效性.通过对实际样机的驱动齿旋向测试,初步证实近似行波的形成及传播的存在.初步的样机特

  12. Lamb Wave Multi-touch Ultrasonic Touchscreen.

    Science.gov (United States)

    Firouzi, Kamyar; Nikoozadeh, Amin; Carver, Thomas; Khuri-Yakub, Butrus

    2016-09-13

    Touchscreen sensors are widely used in many devices such as smart phones, tablets, laptops, etc., with diverse applications. We present the design, analysis, and implementation of an ultrasonic touchscreen system that utilizes interaction of transient Lamb waves with objects in contact with the screen. It attempts to improve on the existing ultrasound technologies, with the potential of addressing some of the weaknesses of the dominant technologies, such as the capacitive or resistive ones. Compared to the existing ultrasonic and acoustic modalities, among other advantages, it provides the capability of detecting several simultaneous touch points, and also a more robust performance. The localization algorithm, given the hardware design, can detect several touch points with a very limited number of measurements (one or two). This in turn can significantly reduce the manufacturing cost.

  13. Torsional ultrasonic wave based level measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, David E. (Oak Ridge, TN); Kisner, Roger A. (Knoxville, TN)

    2012-07-10

    A level measurement system suitable for use in a high temperature and pressure environment to measure the level of coolant fluid within the environment, the system including a volume of coolant fluid located in a coolant region of the high temperature and pressure environment and having a level therein; an ultrasonic waveguide blade that is positioned within the desired coolant region of the high temperature and pressure environment; a magnetostrictive electrical assembly located within the high temperature and pressure environment and configured to operate in the environment and cooperate with the waveguide blade to launch and receive ultrasonic waves; and an external signal processing system located outside of the high temperature and pressure environment and configured for communicating with the electrical assembly located within the high temperature and pressure environment.

  14. Design of a Mode Conversion Ultrasonic Motor for Position Control

    Science.gov (United States)

    LeLetty, Ronan; Bouchilloux, Philippe; Claeyssen, Frank; Lhermet, Nicolas

    1996-01-01

    The many useful characteristics of ultrasonic motors, such as high holding torques, and high torque at low speeds, have made them the subject of increasing interest. In addition, several of their characteristics make them attractive for aerospace applications: they have a torque to weight ratio, and they require neither gearing mechanisms nor lubrication. Moreover, they create negligible magnetic fields, and conversely, they are not affected by external magnetic fields. Ultrasonic motors based on bolt-tightened structures offer simplicity and high stress capability. They use the inverse piezoelectric effect in the stator to produce vibrational energy, which is transferred to the rotor by friction. We designed a bolt-tightened ultrasonic motor using numerical modelling tools (finite element and electromechanical circuit analyses), creating an equivalent circuit model that takes into account the electromechanical energy conversion in the stator and the contact between the stator and the rotor. Analysis of the circuit gives insight into the behavior of the motor and allows its performance to be calculated. Two prototypes of the motor were built; their transient responses and other quantities, such as starting torque, were measured. In this paper, we discuss the numerical and the experimental results, and demonstrate the usefulness of numerical analysis in designing ultrasonic motors and estimating their performance.

  15. An estimation of load characteristics of an ultrasonic motor by measuring transient responses.

    Science.gov (United States)

    Nakamura, K; Kurosawa, M; Kurebayashi, H; Ueha, S

    1991-01-01

    To measure the characteristics of ultrasonic motors, such as the maximum torque, torque-speed relationship and the frictional coefficient at the contact surface, a method in which the torque is calculated from the transient responses is proposed. The rise curve that is the transitional change in the rotor speed soon after turning on the motor gives the load characteristics, while the fall curve that is the decay of the rotor speed after turning off the motor yields the frictional coefficient of the contact surface. This method requires only a short time (the transient time of the motor) to complete the measurement. The relations between the transient responses, the load characteristics and the frictional force are analyzed, and the method is applied to a hybrid transducer type rotary motor and a traveling wave type linear motor.

  16. Theoretical Research on Three-Wave Harmonic Friction Transmission Ultrasonic Motor%三波谐波摩擦传动超声波电动机理论研究

    Institute of Scientific and Technical Information of China (English)

    李霞; 张三川; 陈维山

    2011-01-01

    In order to overcome the unstable problem of the ultrasonic motor in low smooth speed, the harmonic friction drive ultrasonic motor was presented. Frist, the structure of the harmonic friction deceleration ultrasonic motor was described. Then the working principle of the harmonic friction drive was analyzed and the flexspline waveform and the trajectory of the flexspline particle was discussed. Finally, the transmission ratio was studied, its transmission equation was obtained, and the influence on the transmission ratio was studied. The results lay a theoretical foundation to further improvement of the output performance of the ultrasonic motor.%为克服行波超声波电动机低速平滑性不稳定的问题,提出一种谐波摩擦超声波电动机.首先对谐波摩擦超声波电动机的结构进行研究,然后分析谐波摩擦传动的原理、柔轮波形曲线的理论模型以及柔轮质点的运动轨迹.最后研究了谐波摩擦传动系统的传动比,获得其传动比方程,分析传动比的影响因素.研究结果为进一步提高超声波电动机的输出性能奠定了理论基础.

  17. Model based defect detection for free stator of ultrasonic motor

    DEFF Research Database (Denmark)

    Amini, Rouzbeh; Mojallali, Hamed; Izadi-Zamanabadi, Roozbeh;

    2007-01-01

    In this paper, measurements of admittance magnitude and phase are used to identify the complex values of equivalent circuit model for free stator of an ultrasonic motor. The model is used to evaluate the changes in the admittance and relative changes in the values of equivalent circuit elements....... This method identifies the damages and categorizes them. The validity of the method is verified by using free stator measurements of defect free stators of a recently developed multilayer piezoelectric motor....

  18. Performance improvement of rectangular-plate linear ultrasonic motors using dual-frequency drive.

    Science.gov (United States)

    Ming, Yang; Richardson, Robert C; Levesley, Martin C; Walker, Peter G; Watterson, Kevin

    2004-12-01

    To improve the performances of a rectangular-plate linear ultrasonic motor for specific applications, a dual-frequency drive has been proposed and investigated. Through careful design of the rectangular piezoelectric ceramic plate, its first longitudinal resonant frequency coincides with its second lateral bending resonant frequency and is one-third of its higher lateral bending resonant frequency. When a square-wave voltage is used to drive the motor, its first longitudinal and second bending and the higher bending vibration modes are excited. Experimental results show that the maximum thrust force and maximum velocity of the motor are over 170% of those obtained from the single-frequency sine-wave drive when the voltage performance of the motor becomes saturated.

  19. Liquid level sensor using ultrasonic Lamb waves.

    Science.gov (United States)

    Sakharov, V E; Kuznetsov, S A; Zaitsev, B D; Kuznetsova, I E; Joshi, S G

    2003-06-01

    This paper describes a novel, noninvasive method for measurement of liquid level in closed metal tanks that are under high pressure. It is based on the use of ultrasonic Lamb waves propagating along the tank wall. Contact with liquid substantially changes the characteristics of these waves and this can be used as an indicator of liquid presence. Theoretical analysis shows that the symmetric and antisymmetric Lamb wave modes, both fundamental and higher order, are sensitive to presence of the liquid. The optimal wave frequency depends on the thickness of the tank wall and wall material. A prototype level sensor based on this principle has been developed. It uses two pairs of wedge transducers to generate and detect Lamb waves propagating along the circumference of the gas tank. An operating frequency of 100 kHz is found to be optimal for use with tanks having a wall thickness of 30-50 mm. Prototype sensors developed under this program have been used successfully in oil fields in the far northern region of Russia.

  20. CONTRIBUTIONS TO THE FINITE ELEMENT MODELING OF LINEAR ULTRASONIC MOTORS

    Directory of Open Access Journals (Sweden)

    Oana CHIVU

    2013-05-01

    Full Text Available The present paper is concerned with the main modeling elements as produced by means of thefinite element method of linear ultrasonic motors. Hence, first the model is designed and then a modaland harmonic analysis are carried out in view of outlining the main outcomes

  1. Development of a novel ultrasonic motor resonator using topology optimization

    CSIR Research Space (South Africa)

    M'Boungui, G

    2011-01-01

    Full Text Available The use of topology optimization in the design of a novel stator for an ultrasonic motor (USM) is investigated. The design challenge is to produce a stator, with two resonant modes whose frequencies are in a ratio of 1:2. When driven together...

  2. CONTRIBUTIONS TO THE FINITE ELEMENT MODELING OF ROTARY ULTRASONIC MOTORS

    Directory of Open Access Journals (Sweden)

    Oana CHIVU

    2013-05-01

    Full Text Available The present paper is concerned with the main modeling elements as produced by means of thefinite element method of rotary ultrasonic motors. Hence, first the model is designed and then a modaland harmonic analysis are carried out in view of outlining the main outcomes

  3. Self-oscillating Ultrasonic Micro-motor and It’s Application

    Science.gov (United States)

    2003-06-01

    development. 2. Principle and basic construction 2.1 Principle The ultrasonic motors use vibration of an elastic body, therefore there are many different...References 1. T.Takano, Y.Tomikawa and C.Kusakabe, “Same Phase Drive-Type Ultrasonic Motors Using Two Degenerate Bending Vibration Modes of a Disk”, IEEE... Ultrasonic Motors ”, OXFORD SCIENCE PUBRICATIONS (1993) 4. T.Satoh, “Vibration Alarm Analog Quartz Watch with Ultrasonic Micro-motor”, Journal of the

  4. Boundary-reflected waves and ultrasonic coda waves in rock physics experiments

    Science.gov (United States)

    Fu, Bo-Ye; Fu, Li-Yun; Wei, Wei; Zhang, Yan

    2016-12-01

    Ultrasonic coda waves are widely used to study high-frequency scattering. However, ultrasonic coda waves are strongly affected by interference from by boundary-reflected waves. To understand the effect of boundary-reflected waves, we performed ultrasonic experiments using aluminum and shale samples, and the rotating staggered-mesh finite-difference method to simulate the wavefield. We analyzed the wavefield characteristics at the different receiving points and the interference characteristics of the boundary-reflected waves with the ultrasonic coda wave, and the effect of sample geometry on the ultrasonic coda waves. The increase in the aspect ratio of the samples delays the interference effect of the laterally reflected waves and reduces the effect on the ultrasonic coda waves. The main waves interfering with the ultrasonic coda waves are laterally reflected PP-, PS-, PPP-, and PPS-waves. The scattering and attenuation of the high-frequency energy in actual rocks can weaken the interference of laterally reflected waves with the ultrasonic coda waves.

  5. 基于电压调节的行波超声波电机转速模糊PID控制%Fuzzy PID Speed Control of Traveling Wave Ultrasonic Motor Using Voltage Amplitude Regulation

    Institute of Scientific and Technical Information of China (English)

    史敬灼; 张慧敏

    2011-01-01

    Accordance with ultrasonic motor's time-variable nonlinearity, a online adaptive correction based on fuzzy logic was presented. The special nature of ultrasonic motor's speed control were fully taken into account in designing fuzzy rules. The amplitude of driving voltage was used as the control parameter to realite the control method. The experiments indicate that the control characteristics are much better than that of PID controller.%针对超声波电机的时变非线性,给出了基于模糊逻辑的PID控制参数在线自适应校正方法.模糊规则设计中充分考虑了超声波电机转速控制的特殊性.采用驱动电压幅值作为控制量,实现了该控制方法.实验表明,控制性能优于PID控制器.

  6. Simulation of surface acoustic wave motor with spherical slider.

    Science.gov (United States)

    Morita, T; Kurosawa, M K; Higuchi, T

    1999-01-01

    The operation of a surface acoustic wave (SAW) motor using spherical-shaped sliders was demonstrated by Kurosawa et al. (1994). It was necessary to modify the previous simulation models for usual ultrasonic motors because of this slider shape and the high frequency vibration. A conventional ultrasonic motor has a flat contact surface slider and a hundredth driving frequency; so, the tangential motion caused by the elasticity of the slider and stator with regard to the spherical slider of the SAW motor requires further investigation. In this paper, a dynamic simulation model for the SAW motor is proposed. From the simulation result, the mechanism of the SAW motor was clarified (i.e., levitation and contact conditions were repeated during the operation). The transient response of the motor speed was simulated. The relationships between frictional factor and time constant and vibration velocity of the stator and the slider speed were understood. The detailed research regarding the elastic deformation caused by preload would be helpful to construct an exact simulation model for the next work.

  7. Design, modeling and control of a novel multi functional translational-rotary micro ultrasonic motor

    Science.gov (United States)

    Tuncdemir, Safakcan

    The major goal of this thesis was to design and develop an actuator, which is capable of producing translational and rotary output motions in a compact structure with simple driving conditions, for the needs of small-scale actuators for micro robotic systems. Piezoelectric ultrasonic motors were selected as the target actuator schemes because of their unbeatable characteristics in the meso-scale range, which covers the structure sizes from hundred micrometers to ten millimeters and with operating ranges from few nanometers to centimeters. In order to meet the objectives and the design constraints, a number of key research tasks had to be undertaken. The design constraints and objectives were so stringent and entangled that none of the existing methods in literature could solve the research problems individually. Therefore, several unique methods were established to accomplish the research objectives. The methods produced novel solutions at every stage of design, development and modeling of the multi functional micro ultrasonic motor. Specifically, an ultrasonic motor utilizing slanted ceramics on a brass rod was designed. Because of the unique slanted ceramics design, longitudinal and torsional mode vibration modes could be obtained on the same structure. A ring shaped mobile element was loosely fitted on the metal rod stator. The mobile element moved in translational or rotational, depending on whether the vibration mode was longitudinal or torsional. A new ultrasonic motor drive method was required because none of the existing ultrasonic motor drive techniques were able to provide both output modes in a compact and cylindrical structure with the use of single drive source. By making use of rectangular wave drive signals, saw-tooth shaped displacement profile could be obtained at longitudinal and torsional resonance modes. Thus, inheriting the operating principle of smooth impact drive method, a new resonance type inertial drive was introduced. This new technique

  8. Flextensional ultrasonic motor using the contour mode of a square piezoelectric plate.

    Science.gov (United States)

    Leinvuo, Joni T; Wilson, Stephen A; Whatmore, Roger W

    2004-08-01

    This paper presents the design, fabrication, and characterization of a new type of standing wave piezoelectric ultrasonic motor. The motor uses a metallic flextensional amplifier, or cymbal, to convert the contour mode vibrations of a square piezoelectric ceramic plate into flexural oscillations, which are further converted to produce rotary actuation by means of an elastic-fin friction drive. The motor operates on a single-phase electrical supply. A beryllium copper rotor design with three-fin configuration was adopted, and the geometry was varied to include different material thicknesses, fin lengths, and inclinations. The best stall torque and no load speed for a 25-mm square motor were 0.72 Nmm and 895 r/minute, respectively. The behavior of the stator structure was analyzed by ANSYS finite element software using harmonic and modal analyses. The vibration mode estimated by finite element modeling (FEM) was confirmed by laser Doppler vibration measurements.

  9. Comparison of Walking and Traveling-Wave Piezoelectric Motors as Actuators in Kinesthetic Haptic Devices.

    Science.gov (United States)

    Olsson, Pontus; Nysjo, Fredrik; Carlbom, Ingrid B; Johansson, Stefan

    2016-01-01

    Piezoelectric motors offer an attractive alternative to electromagnetic actuators in portable haptic interfaces: they are compact, have a high force-to-volume ratio, and can operate with limited or no gearing. However, the choice of a piezoelectric motor type is not obvious due to differences in performance characteristics. We present our evaluation of two commercial, operationally different, piezoelectric motors acting as actuators in two kinesthetic haptic grippers, a walking quasi-static motor and a traveling wave ultrasonic motor. We evaluate each gripper's ability to display common virtual objects including springs, dampers, and rigid walls, and conclude that the walking quasi-static motor is superior at low velocities. However, for applications where high velocity is required, traveling wave ultrasonic motors are a better option.

  10. Ultrasonic Motors (USM) - an emerging actuation technology for planetary applications

    Science.gov (United States)

    Bao, X.; Das, H.

    2000-01-01

    A hybrid model that addressed a complete ultrasonic motor as a system was developed. The model allows using powerful commercial FE package to express dynamic characteristics of the stator and the rotor in engineering practice. An analog model couples the finite element models for the stator and rotor for the stator-interface layer-rotor syste. The model provides reasonably accurate results for CAD.

  11. Fabricated and friction test anisotropy material of ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    QU Yan-yan; QU Jian-jun; KUANG Nai-hang

    2010-01-01

    The twisters for composed of anisotropic material were designed and manufactured.And two kinds of directional-composites were made:one was fiber direction vertical with frictional interface and another was parallel with frictional interface and moving direction.By varying the proportions of epoxy resin and fiber and arranging the orientations of fiber,the composites anisotropy along longitudinal and circumferential were got.Using density measurement,the mass fraction of resin and fiber were calculated.According to composite mesoscopic mechanics,the elasticity constants of composite were analyzed and calculated.The composite different thicknesses were sliced,and attach to the rotor,then the load characteristics,no-load speed,stop load of ultrasonic motor(USM) were test.The output properties of USM with 0.6 mm thickness composite were superior.The effect of friction material on ultrasonic motor was analyzed.Elastic modulus,thickness and micro-morphology of material are main factors which affect characteristics of ultrasonic motor.

  12. Dynamic Model Identification for Ultrasonic Motor Frequency-Speed Control

    Institute of Scientific and Technical Information of China (English)

    Shi Jingzhuo; Song Le

    2015-01-01

    The mathematical model of ultrasonic motor (USM ) is the foundation of the motor high performance control .Considering the motor speed control requirements ,the USM control model identification is established with frequency as the independent variable .The frequency-speed control model of USM system is developed ,thus laying foundation for the motor high performance control .The least square method and the extended least square method are used to identify the model .By comparing the results of the identification and measurement ,and fitting the time-varying parameters of the model ,one can show that the model obtained by using the extended least square method is reasonable and possesses high accuracy .Finally ,the frequency-speed control model of USM contains the nonlinear information .

  13. Permeability recovery of damaged water sensitive core using ultrasonic waves.

    Science.gov (United States)

    Khan, Nasir; Pu, Chunsheng; Li, Xu; He, Yanlong; Zhang, Lei; Jing, Cheng

    2017-09-01

    It is imperative to recover the well productivity lose due to formation damage nearby wellbore during variant well operations. Some indispensable issues in conventional techniques make ultrasonic technology more attractive due to simple, reliable, favorable, cost-effective, and environment friendly nature. This study proposes the independent and combined use of ultrasonic waves and chemical agents for the treatment of already damaged core samples caused by exposure to distilled water. Results elucidate that ultrasonic waves with optimum (20kHz, 1000W) instead of maximum frequency and power worked well in the recovery owing to peristaltic transport caused by matching of natural frequency with acoustic waves frequency. In addition, hundred minutes was investigated as optimum irradiation time which provided ample time span to detach fine loosely suspended particles. However, further irradiation adversely affected the damaged permeability recovery. Moreover, permeability improvement attributes to cavitation due to ultrasonic waves propagation through fluid contained in porous medium and thermal energy generated by three different ways. Eventually, experimental outcomes indicated that maximum (25.3%) damaged permeability recovery was witnessed by applying ultrasonic waves with transducer #2 (20kHz and 1000W) and optimum irradiation timeframe (100min). This recovery was further increased to 45.8% by applying chemical agent and optimum ultrasonic waves simultaneously. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Damage detection in submerged plates using ultrasonic guided waves

    Indian Academy of Sciences (India)

    Sandeep Sharma; Abhijit Mukherjee

    2014-10-01

    This paper describes a non-contact and non-invasive health monitoring strategy for submerged plate structures using guided waves. The structure under consideration is immersed in water and subjected to longitudinal ultrasonic waves at specific angles of incidence using a cylindrical piezoelectric transducer using the surrounding water as coupling medium. Suitable ultrasonic guided wave modes with optimum scanning capabilities have been generated and identified in submerged plate system. Finally, the propagation of selected modes through submerged notched plates is investigated. Sensitivity of leaky waves to the notches has been studied. The methodology would help in identifying damages in the submerged plate structures.

  15. Detection of Laser Generated Ultrasonic Wave Using Michelson Interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Cho; Yamawaki, Hisashi [Japan National Research Institute, Ibaraki (Japan); Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2000-02-15

    In this paper, ultrasonic wave in the thermoelastic regime was generated in a steel disk by illuminating a pulse laser (Q-switched Nd:YAG) on the surface of the sample and was detected on the other side by Michelson interferometer which was stabilized by feed back control. The experimentally detected displacement waveform of the ultrasonic wave showed good agreement with the theoretically expected one. Also it was shown that sound speeds of longitudinal and shear wave were similar to ones measured by pulse-echo method using a contact transducer. As an application of the noncontact ultrasonic measurement by using laser based ultrasonics, the sound speed in the sample was monitored while the sample was heated in a furnace, and the result showed that it decreased according to the increase of sample temperature

  16. Application of Ultrasonic Waves on Maintaining Freshness of Tilapia Fillet

    Directory of Open Access Journals (Sweden)

    Ruddy Suwandi

    2015-06-01

    Full Text Available ish fillet is one of fisheries products that easily deteriorated; hence handling techniques are needed to maintain the freshness. Ultrasonic wave have been widely applied to some of food products for maintaining freshness through microbial inactivation, however the ultrasonic application to fisheries products has not been reported. The purpose of this study was to analyze the effect of ultrasonic wave on fish freshness. The stages of the study were sample preparation, sonication, freshness parameters examination and histology observation. Ultrasonic wave did not affectthe organoleptic value and the TVB, but affected the pH value and the TPC. The sample in which the TPC value was found significantly different, were further observed after 48 and 96 hours storage. The result showed that the TPC value of sonicated sample for 9 minutes was lower to that of without sonication. Histology analysis showed, however, sonication made the structure of muscle fiber less compact and deformation of myomer was found.

  17. Phased annular array transducers for ultrasonic guided wave applications

    Science.gov (United States)

    Yan, Fei; Borigo, Cody; Liang, Yue; Koduru, Jaya P.; Rose, Joseph L.

    2011-04-01

    Mode and frequency control always plays an important role in ultrasonic guided wave applications. In this paper, theoretical understanding of guided wave excitations of axisymmetric sources on plate structures is established. It is shown that a wave number spectrum can be used to investigate the guided wave excitations of an axisymmetric source. The wave number spectrum is calculated from a Hankel transform of the axial source loading profile. On the basis of the theoretical understanding, phased annular array transducers are developed as a powerful tool for guided wave mode and frequency control. By applying appropriate time delays to phase the multiple elements of an annular array transducer, guided wave mode and frequency tuning can be achieved fully electronically. The phased annular array transducers have been successfully used for various applications. Example applications presented in this paper include phased annular arrays for guided wave beamforming and a novel ultrasonic vibration modal analysis technique for damage detection.

  18. Contribution of ultrasonic traveling wave to chemical-mechanical polishing.

    Science.gov (United States)

    Li, Liang; He, Qing; Zheng, Mian; Liu, Zheng

    2015-02-01

    The ultrasonic vibrators are introduced into the chemical-mechanical polishing devices, and in this polishing system, the ultrasonic vibrators generate ultrasonic traveling wave and keep coaxial with the polished silicon wafer rotating at given speed so as to compare the texture of the polished silicon wafers. And the experiments on the chemical-mechanical polishing with assisted ultrasonic vibration are accomplished in order to investigate the effect of the ultrasonic vibration on the chemical-mechanical polishing. Via comparing the roughness average of the two silicon wafers polished with assisted ultrasonic vibration and without assisted vibration, it is found that the morphology of the silicon wafer polished with assisted vibration is superior to that without assisted vibration, that is, this series of experiments indicate that the ultrasonic vibration is beneficial to the chemical-mechanical polishing. Aiming at understanding the contribution of the ultrasonic vibration to chemical-mechanical polishing in detail, the model of the chemical-mechanical polishing with the assisted ultrasonic vibration is built up, which establishes the relationship of the removal rate and the polishing variables such as the rotary speed of silicon wafers, the amplitude and the frequency of vibrators, the particle density of polishing slurry and the characteristics of polishing pad etc. This model not only could be used to explain the experimental results but also to illuminate the roles played by the polishing variables.

  19. Performance evaluation of a micro ultrasonic motor using a one-cubic-millimeter stator.

    Science.gov (United States)

    Mashimo, Tomoaki

    2015-10-01

    A piezoelectric ultrasonic motor has two significant advantages, high energy density and simple structure, and these advantages can help in the miniaturization of the motor. We build a prototype micro ultrasonic motor using a stator with a volume of approximately 1 cubic millimeter. To evaluate its representative performance values (torque, angular velocity, and energy efficiency), we built an experimental setup and operated the prototype motor by varying experimental conditions, such as the preload between the stator and rotor and the amplitude of voltages applied to motor. The performance values obtained at the millimeter to sub-millimeter scale are discussed analytically using the macro scale models of ultrasonic motors. Experimentally, the prototype motor has generated a torque of more than 10 μNm with a 1-cubic-millimeter stator. The motor described herein is now the smallest micro ultrasonic motor with a practical torque, although its efficiency is still low.

  20. Using Ultrasonic Lamb Waves To Measure Moduli Of Composites

    Science.gov (United States)

    Kautz, Harold E.

    1995-01-01

    Measurements of broad-band ultrasonic Lamb waves in plate specimens of ceramic-matrix/fiber and metal-matrix/fiber composite materials used to determine moduli of elasticity of materials. In one class of potential applications of concept, Lamb-wave responses of specimens measured and analyzed at various stages of thermal and/or mechanical processing to determine effects of processing, without having to dissect specimens. In another class, structural components having shapes supporting propagation of Lamb waves monitored ultrasonically to identify signs of deterioration and impending failure.

  1. Yeast Cell Trapping In Ultrasonic Wave Field Using Ultrasonic Contrast Agent

    Science.gov (United States)

    Yamakoshi, Yoshiki; Koitabashi, Yusuke; Nakajima, Naritsugu; Miwa, Takashi

    2006-05-01

    Microobject manipulation using ultrasonic waves is expected to play important roles in constructing future drug or gene delivery systems. The acoustic radiation force, which is applied to microobjects, traps the objects at the desired position. A microjet, which is produced by bubble explosion under high-intensity ultrasonic waves, creates microholes through the cell membrane (sonoporation), which is considered as a sophisticated method of improving the doses of drugs or genes injected into a tissue. Aiming at increasing the trapping force in micro bubble manipulation using ultrasonic waves, we have proposed a novel method based on the self-organization of microbubbles. This method uses seed bubbles in order to trap the target bubbles. In this study, the proposed method is applied to yeast cell trapping using ultrasonic waves. An ultrasonic wave contrast agent (Levovist; Shering A.G., Germany) is used as a seed bubble. It is shown that the number of trapped yeast cells depends on the preparation of the yeast cells. In order to evaluate the result, two additional experiments are carried out by changing the internal gas of the seed bubbles and by using bubbles with a polymer shell.

  2. OPTIMAL DESIGN FOR STATOR OF THREE-DOF ULTRASONIC MOTOR

    Institute of Scientific and Technical Information of China (English)

    ZHAOChun-sheng; LIZhi-rong; HUANGWei-qing

    2004-01-01

    A 3-DOF ultrasonic motor with a cylindershaped stator and a spherical rotor is developed. The motor provides 3-DOF rotation around x, y. and z-axes implemented by two second order bending modes with orthogonality and one first order longitudinal mode of the stator, The three modes must satisfy some conditions. In our previous research, in order to satisfy these conditions, a parameter fitting design method is used. However, it is an experiential design method with low efficiency and costs much time, sometimes it even cannot find a desired solution, This paper puts forward an optimal design method for the stator. Based on the method, an optimization program is developed in MATLAB environment. Using the program, a new prototype of 3-DOF ultrasonic motor is designed. Its stator has diameter of 20 ram. height of 67 mm, and mass of 157 g. Experimental results show that the measured stators' modal frequencies and modal shapes are in good consistent agreement with the results obtained by the optimal design program.

  3. Force transfer model and characteristics of hybrid transducer type ultrasonic motors.

    Science.gov (United States)

    Guo, Jifeng; Gong, Shujuan; Guo, Haixun; Liu, Xiao; Ji, Kehui

    2004-04-01

    The characteristics of longitudinal-torsional hybrid transducer-type ultrasonic motors (HTUSM) are low speed and high torque. The discontinuous-surface-contact mode between the stator and the rotor is different from the many-point-contact mode of traveling wave motors, which is also an essential cause for high torque. Therefore, it is important to analyze its force transfer model between the rotor and the stator. In this paper, issues of using the method of equivalent circuit model are addressed. The relationships between the contact angle, preload, and physical parameters of frictional materials are given, according to the impulse conservation law axially. The equations describing output torque, amplitudes of longitudinal and torsional vibration, and parameters of the rotor are derived according to the principle that the work done by the load is equal to that by the driving force in one vibrating cycle. All factors that influence the mechanical characteristics are analyzed, and accuracy and suitability of the force transfer model are verified by comparison with the prototype motor. The formula for transfer efficiency on the stator/rotor interface is given, and the low-efficiency of this type motor is explained. The wide-working frequency range property of this type motor is shown with experimental results. Based on this study, the parameters of the rotor and preload are determined. The maximum torque of the prototype motor is up to 13.2 nm, and no-load speed of this type of motor is 12.5 rpm.

  4. Improvement of solar ethanol distillation using ultrasonic waves

    Directory of Open Access Journals (Sweden)

    Jaruwat Jareanjit

    2016-08-01

    Full Text Available This report presents a study on the use of ultrasonic waves in solar ethanol distillation to investigate the performance of ultrasonic waves at a frequency of 30 kHz and at 100 Watts that were installed in the inlet area of a 10-litre distillation tank. Based on the non-continuous distillation process (batch distillation, the experiment demonstrated that using ultrasonic waves in solar ethanol distillation caused the average concentration of hourly distilled ethanol to be higher than that of a normal system (solar ethanol distillation without ultrasonic wave at the same or higher distillation rate and hourly distillation volume. The ultrasonic wave was able to enhance the separation of ethanol from the solution (water-ethanol mixture through solar distillation. The amount of pure ethanol product from each distilled batch was clearly larger than the amount of product obtained from a normal system when the initial concentration of ethanol was lower than 50%v/v (% by volume, where an average of approximately 40% and 20% are obtained for an initial ethanol concentration of 10%v/v and 30%v/v, respectively. Furthermore, the distillation rate varied based on the solar radiation value.

  5. Analysis of shaking beam actuator for piezoelectric linear ultrasonic motor.

    Science.gov (United States)

    Lee, Kyongjai; Lee, Dong-Kyun; Borodinas, Sergejus; Vasiljev, Piotr; Nahm, Sahn; Yoon, Seok-Jin

    2004-11-01

    In this paper, piezoelectric linear ultrasonic motors (PLUM) have been investigated on the elliptic trajectory of a contact point in shaking beam, which has been accomplished by two resonance vibration modes of the actuators. The actuators have generated the vibration modes, longitudinal and flexural, by two longitudinal mechanical vibrations with phase difference of pi/2. Modal and harmonic analysis of the shaking beam actuator were performed by the finite element method (FEM) to calculate a resonance frequency and a modal shape and to perform harmonic response. Experimental results proved that a contact point of the PLUM tends to move with an elliptic trajectory.

  6. Integration simulation method concerning speed control of ultrasonic motor

    Science.gov (United States)

    Miyauchi, R.; Yue, B.; Matsunaga, N.; Ishizuka, S.

    2016-09-01

    In this paper, the configuration of control system of the ultrasonic motor (USM) from finite element method (FEM) model by applying the nonlinear model order reduction (MOR) is proposed. First, the USM and the FEM model is introduced. Second, FEM model order reduction method is described. Third, the result of comparing the computing time and accuracy of the FEM model and reduced order model is shown. Finaly, nominal model for control is derived by system identification from reduced order model. Nonlinear model predictive control (NMPC) is applied to the nominal model, and speed is controlled. the controller effect is comfirmed by applying the proposed reduced order model.

  7. Non-contact feature detection using ultrasonic Lamb waves

    Science.gov (United States)

    Sinha, Dipen N [Los Alamos, NM

    2011-06-28

    Apparatus and method for non-contact ultrasonic detection of features on or within the walls of hollow pipes are described. An air-coupled, high-power ultrasonic transducer for generating guided waves in the pipe wall, and a high-sensitivity, air-coupled transducer for detecting these waves, are disposed at a distance apart and at chosen angle with respect to the surface of the pipe, either inside of or outside of the pipe. Measurements may be made in reflection or transmission modes depending on the relative position of the transducers and the pipe. Data are taken by sweeping the frequency of the incident ultrasonic waves, using a tracking narrow-band filter to reduce detected noise, and transforming the frequency domain data into the time domain using fast Fourier transformation, if required.

  8. Diffraction of collinear correlated photon pairs by an ultrasonic wave

    CERN Document Server

    Kwiek, Piotr

    2013-01-01

    The phenomenon of collinear photon pairs diffraction by an ultrasonic wave is investigated for Bragg incidence. A BBO crystal was used for producing collinear correlated photon pairs via type-I spontaneous parametric down-conversion. The experimental setup for diffraction of collinear correlated photon pairs was tested based on Malus' law for pairs of photons. The obtained results do not support the L. B. Deng's theory of 2012, presented in his work entitled "Diffraction of entangled photon pairs by ultrasonic waves" [Front. Phys. 7, 239 (2012)] . An alternative simple theoretical description of interaction of collinear photon pairs with ultrasonic waves is shown in the present paper which reveals very good agreement with corresponding experimental data.

  9. Frequency-Speed Control Model Identification of Ultrasonic Motor Using Step Response

    Institute of Scientific and Technical Information of China (English)

    Shi Jingzhuo; Zhang Caixia

    2015-01-01

    Control model of ultrasonic motor is the foundation for high control performance .The frequency of driv-ing voltage is commonly used as control variable in the speed control system of ultrasonic motor .Speed control model with the input frequency can significantly improve speed control performance .Step response of rotating speed is tested .Then ,the transfer function model is identified through characteristic point method .Considering time-varying characteristics of the model parameters ,the variables are fitted with frequency and speed as the inde-pendent variables ,and the variable model of ultrasonic motor system is obtained ,with consideration of the nonlin-earity of ultrasonic motor system .The proposed model can be used in the design and analysis of the speed control system in ultrasonic motor .

  10. Laser detection of ultrasonic waves with concave portions of the wave fronts.

    Science.gov (United States)

    Korkh, Yulia; Perov, Dmitry; Rinkevich, Anatoly

    2012-10-01

    Special features of ultrasonic pulse wave field detection with concave regions of the wave fronts are investigated with the use of ultrasonic laser interferometry technique. Experimental proofs of the wave front with concave regions are obtained and it is found that the nonmonotonic wave front profiles are well described by the fourth-order even polynomial. The model proposed is applied to the investigation of the spatiotemporal structure of elastic wave fields on solid surfaces. The results obtained can be used for estimating the local wave front curvature.

  11. Nondestructive Testing Residual Stress Using Ultrasonic Critical Refracted Longitudinal Wave

    Science.gov (United States)

    Xu, Chunguang; Song, Wentao; Pan, Qinxue; Li, Huanxin; Liu, Shuai

    Residual stress has significant impacts on the performance of the mechanical components, especially on its strength, fatigue life and corrosion resistance and dimensional stability. Based on theory of acoustoelasticity, the testing principle of ultrasonic LCR wave method is analyzed. The testing system of residual stress is build. The method of calibration of stress coefficient is proposed in order to improve the detection precision. At last, through experiments and applications on residual stress testing of oil pipeline weld joint, vehicle's torsion shaft, glass and ceramics, gear tooth root, and so on, the result show that it deserved to be studied deeply on application and popularization of ultrasonic LCR wave method.

  12. Ultrasonic Waves in Water Visualized With Schlieren Imaging

    Science.gov (United States)

    Juergens, Jeffrey R.

    2000-01-01

    The Acoustic Liquid Manipulation project at the NASA Glenn Research Center at Lewis Field is working with high-intensity ultrasound waves to produce acoustic radiation pressure and acoustic streaming. These effects can be used to propel liquid flows to manipulate floating objects and liquid surfaces. Interest in acoustic liquid manipulation has been shown in acoustically enhanced circuit board electroplating, microelectromechanical systems (MEMS), and microgravity space experiments. The current areas of work on this project include phased-array ultrasonic beam steering, acoustic intensity measurements, and schlieren imaging of the ultrasonic waves.

  13. A new hybrid piezoelectric ultrasonic motor with two stators

    Institute of Scientific and Technical Information of China (English)

    YI You-ping; Wolfgang Seemann; Rainer Gausmann; ZHONG Jue

    2005-01-01

    A new hybrid piezoelectric ultrasonic motor, which consists of one rotor and two stators, was proposed in this paper. In order to match the resonance frequencies of longitudinal vibration and torsional vibration excited in the stators, a symmetrical structure was adopted in design of the motor. A so-called mass matching method, namely adding two rings to the outside circumference of the two stators respe ctively, was used to adjust the resonance frequencies of these two vibrations. A finite element model was developed using ANSYS software for the purpose of analyzing the resonance frequencies of longitudinal vibration and torsional vibration as well as the function of the adjusting rings. The results show that the resonance frequency of torsional vibration varies with the position of the ring, but the resonance frequency of longitudinal vibration changes little. By means of adjusting the mass and the position of the rings, the first order resonance frequency of longitudinal vibration is coincided with that of torsional vibration and the value is 20.75 kHz. An experimental prototype motor was fabricated according to the analytical results and its performance is in agreement with the theoretical predictions. The speed of motor reaches the maximum 92 r/min at the working frequency 19.0 kHz.

  14. A new rotary ultrasonic motor using longitudinal vibration transducers

    Directory of Open Access Journals (Sweden)

    Xiangyu Zhou

    2015-05-01

    Full Text Available To simplify the design process and improve the motor performance, a rotary ultrasonic motor with rotationally symmetrical structure has been designed, fabricated, and characterized. The stator consists of four connected sandwich-type transducers and eight driving feet. The rotor, a disk, and a disk-shaft are pressed on the two sides of the stator by a nut–spring system. To drive the rotor, two orthogonal longitudinal vibration modes of the stator should be excited. The operating principle of the rotary motor was analyzed by a mathematical model. By using finite element analysis, the feasibility of the operating principle was validated, and the optimal structure dimensions of stator were determined in order to improve the driving teeth motion. The overall dimensions of the prototype stator are 30 mm (width × 30 mm (width × 50 mm (length. Driven by alternating current signals with the driving frequency of 50.93 kHz and voltage 300 VP-P, the motor gave a maximal no-load speed of 157.9 r/min and a maximal output torque of 11.76 mN m.

  15. Systematic modeling for free stators of rotary - Piezoelectric ultrasonic motors

    DEFF Research Database (Denmark)

    Mojallali, Hamed; Amini, Rouzbeh; Izadi-Zamanabadi, Roozbeh

    2007-01-01

    An equivalent circuit model with complex elements is presented in this paper to describe the free stator model of traveling wave piezoelectric motors. The mechanical, dielectric and piezoelectric losses associated with the vibrator are considered by introducing the imaginary part to the equivalent...

  16. Some constructions and characteristics of rod-type piezoelectric ultrasonic motors using longitudinal and torsional vibrations.

    Science.gov (United States)

    Tomikawa, Y; Adachi, K; Aoyagi, M; Sagae, T; Takano, T

    1992-01-01

    Ultrasonic motors using longitudinal and torsional motions of rod vibrators have previously been proposed. Several motor constructions, whose forms are different from the previous ones, are proposed and their characteristics are experimentally examined in order to develop the ultrasonic motors of this type; that is, they are expected to have much different uses, according to how their forms are modified. Two groups of motor are dealt with: one contains motors basically suited to the relatively high torque of 2-3 kgf-cm and the other contains motors for small or medium torque below about 1.0 kgf-cm. As the result, operational characteristics of motors are totally revealed. These are useful in developing the rod type ultrasonic motors and in their practical applications.

  17. Simplified modeling and generalized predictive position control of an ultrasonic motor.

    Science.gov (United States)

    Bigdeli, Nooshin; Haeri, Mohammad

    2005-04-01

    Ultrasonic motors (USM's) possess heavy nonlinear and load dependent characteristics such as dead-zone and saturation reverse effects, which vary with driving conditions. In this paper, behavior of an ultrasonic motor is modeled using Hammerstein model structure and experimental measurements. Also, model predictive controllers are designed to obtain precise USM position control. Simulation results indicate improved performance of the motor for both set point tracking and disturbance rejection.

  18. Monitoring of fatigue crack growth using guided ultrasonic waves

    Science.gov (United States)

    Masserey, B.; Kostson, E.; Fromme, P.

    2010-04-01

    Varying loading conditions of aircraft structures result in stress concentration at fastener holes, where multi layer components are connected, possibly leading to the development of fatigue cracks. Guided ultrasonic waves propagating along a structure allow in principle for the efficient non-destructive testing of large plate-like structures, such as aircraft wings. This contribution presents a study of the detection and monitoring of fatigue crack growth using both low frequency and higher frequency guided ultrasonic wave modes. Two types of structures were used, single layer aluminum tensile specimens, and multi layer structures consisting of two adhesively bonded aluminum plate-strips. Fatigue experiments were carried out and it was shown that fatigue crack detection and growth monitoring at a fastener hole during cyclic loading using both guided wave types is possible. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack detection at critical and difficult to access fastener locations. Good agreement was observed between the experimental results and predictions from full three-dimensional numerical simulations of the scattering of the low frequency guided ultrasonic wave at the fastener hole and crack. The robustness of the methodology for practical in-situ ultrasonic monitoring of fatigue crack growth is discussed.

  19. Ultrasonic guided wave focusing by a generalized phased array

    Science.gov (United States)

    Zhang, Bixing; Xie, Fuli; Dong, Hefeng; Gong, Junjie

    2013-01-01

    Ultrasonic guided wave focusing by a generalized phased array is studied based on dispersion curves in a multi-layered medium. The different phase of the guided waves with different frequency is added on the excitation signal on each element of the transducer array for focusing. This can be realized by designing a proper excitation pulse based on the dispersion curves of the guided waves for each of the transducer array elements. The numerical simulation results show that the guided waves with different modes, different frequency components, and from different elements of the transducer array can all be focused at the target and focusing is achieved.

  20. Ultrasonic wave interactions with magnetic colloids

    CERN Document Server

    Chapman, J R

    2001-01-01

    fluids have been performed in an effort to determine the relative stability of the fluids. The experimental results have been compared with a combined scattering and hydrodynamic model (Allegra and Hawley 1972) and the ultrasonic anisotropy theory of Skumiel (1997). An on-line quality assurance process is proposed. Originally invented as a method for moving spacecraft fuel in weightless conditions, magnetic colloids or ferrofluids are now used in applications as diverse as the dissipation of heat in the voice coils of a loudspeaker, and for the separation of scrap metal. It has been found that aqueous ferrofluids become unstable after a period of time and with dilution. Therefore, there is a need to characterize the colloidal fluid to study the effects of degradation. Additionally, due to the high cost of ferrofluids and the large volumes required for some applications, the fluid is recycled. It is therefore necessary to develop a system for quality assurance for the fluid reclamation process. Ultrasonic meth...

  1. The treatment of radioactive wastewater by ultrasonic standing wave method

    Energy Technology Data Exchange (ETDEWEB)

    Su-xia, Hou, E-mail: hsxljj@sina.com; Ji-jun, Luo; Bin, He; Ru-song, Li; Tao, Shen

    2014-06-01

    Highlights: • USWM can be considered as the green cleaning separation techniques. • A physical model of suspended radioactive particle is established. • A computer program is developed to achieve numerical calculation and analysis. • The experimental device for low-level radioactive wastes treatment is designed. • Lots of experimental data are used to analysis the influence of the parameters. - Abstract: The radiation hazards of radionuclide arising from the storage of nuclear weapons cannot be ignored to the operators. Ultrasonic standing wave methods can be considered as the green cleaning separation techniques with high efficiency. The application of ultrasonic standing wave methods for liquid radioactive wastes treatment requires solving many problems connected with the proper selection of the frequency and power of ultrasonic transducers, and the processing time, etc. Based on the model of one single suspended radioactive particle subjected to in the field of ultrasonic standing wave, the principle of the treatment of low-level radioactive wastewater by ultrasound was analyzed. The theoretical and simulation results show that under the action of ultrasonic standing wave, the particle will move toward the wave node plane, and the time of particle reaching the plane become shorter when the radius of particle and the frequency and power of ultrasound was enlarged. The experimental results show that the radioactive concentration of wastewater could be reduced from 400 Bq L{sup −1} to 9.3 Bq L{sup −1} and the decontamination efficiency was 97.68%. The decontamination efficiency could not be obviously improved by further increasing the treating time.

  2. High resolution miniaturized stepper ultrasonic motor using differential composite motion.

    Science.gov (United States)

    Chu, Xiangcheng; Xing, Zengping; Li, Longtu; Gui, Zhilun

    2004-03-01

    Experiments show that there is a limited minimum stepped angle in ultrasonic motors (USM). The research on the minimum angle of stepper USM with 15 mm in diameter and wobbling mode is being carried out. This paper presents a novel way to decrease the minimum stepped angle of USM based on the principle of differential composite motion (DCM), i.e. clockwise and counterclockwise rotation. The prototype was fabricated and experiments proved that this method is useful and also keeps a high torque for a large stepped angle. The stator of the prototype is steel, and rotor is fiberglass, antifriction material or steel. The prototype can operate well over 150 h with a 5 kHz wide frequency band. The minimum stepped angle is 46" using a coventional method while 12" using DCM method proposed in this paper.

  3. CYLINDER-SPHERE 3-DOF ULTRASONIC MOTOR AND ITS CONTROL

    Institute of Scientific and Technical Information of China (English)

    HUANGWei-qing; ZHANFeng-jiang; ZHAOChun-sheng

    2004-01-01

    A three degree-of-freedom (DOF) ultrasonic motor (USM) with a cylinder-shaped stator and a spherical rotor is introduced, which uses one first order longitudinal and two second order bending nature vibration modes of the cylinder. Control strategies for the two DOF trajectory following are studied and applied to the prototype USM. Vibration amplitude control is employed for speed regulation. The first trajectory following strategy is a step-by-step interpolation. The second strategy is vector decomposition control. Three pulse width modulation (PWM) methods for the exciting voltage regulation are investigated. These methods are compared and verified by several experiments. The key is to keep the phase differences of the three vibration constants and small exciting voltage distortion while the exciting voltages are changed for simplifing the control process and obtaining good control performance. The vector control method has advantages of small trajectory following error, smooth moving and low noise.

  4. Fuzzy logic based DSP controlled servo position control for ultrasonic motor

    Energy Technology Data Exchange (ETDEWEB)

    Bal, G.; Demirbas, S.; Colak, I. [Gazi University, Ankara (Turkey). Electrical Dept.; Bekiroglu, E. [Abant Izzet Baysal University, Bolu (Turkey). Dept. of Electrical and Electronics Engineering

    2004-12-01

    In this paper, position control of an ultrasonic motor was implemented on the basis of fuzzy reasoning. A digitally controllable two phase serial resonant inverter was developed to drive the ultrasonic motor by using a TMS320F243 digital signal processor. The driving frequency was used as a control input in the position control loop. The position characteristics obtained from the proposed drive and control system were demonstrated and evaluated by experiments. The experimental results verify that the developed position control scheme is highly effective, reliable and applicable for the ultrasonic motor. (author)

  5. Selective generation of ultrasonic Lamb waves by electromagnetic acoustic transducers

    Science.gov (United States)

    Li, Ming-Liang; Deng, Ming-Xi; Gao, Guang-Jian

    2016-12-01

    In this paper, we describe a modal expansion approach for the analysis of the selective generation of ultrasonic Lamb waves by electromagnetic acoustic transducers (EMATs). With the modal expansion approach for waveguide excitation, an analytical expression of the Lamb wave’s mode expansion coefficient is deduced, which is related to the driving frequency and the geometrical parameters of the EMAT’s meander coil, and lays a theoretical foundation for exactly analyzing the selective generation of Lamb waves with EMATs. The influences of the driving frequency on the mode expansion coefficient of ultrasonic Lamb waves are analyzed when the EMAT’s geometrical parameters are given. The numerical simulations and experimental examinations show that the ultrasonic Lamb wave modes can be effectively regulated (strengthened or restrained) by choosing an appropriate driving frequency of EMAT, with the geometrical parameters given. This result provides a theoretical and experimental basis for selectively generating a single and pure Lamb wave mode with EMATs. Project supported by the National Natural Science Foundation of China (Grant Nos. 11474361 and 11274388).

  6. A rotary ultrasonic motor using radial bending mode of ring with nested PZT excitation

    Institute of Scientific and Technical Information of China (English)

    Ying-xiang LIU; Jun-kao LIU; Wei-shan CHEN; Xiao-hui YANG

    2012-01-01

    This study presents and verifies a new idea for constructing a rotary traveling wave ultrasonic motor (USM) that uses the radial bending mode of a ring.In the new design,20 trapezoid cross section slots are cut symmetrically in the outer surface of a thick duralumin alloy ring,where 20 PZT stacks are nested.In each slot,two wedging blocks are set between the PZT stack and the two sides of the slot respectively to apply preloading on the PZT ceramics.Two radial bending modes of the stator that have a phase difference of a quarter wavelength on space are generated by using the d33 operating mode of the PZT elements,and then a flexural traveling wave is formed by the superimposing of two standing waves whose amplitudes are equal and phases are different by 90° temporally.Two conical rotors are pressed to each end of the ring type stator by a coiled spring.The finite element method (FEM) simulation is developed to validate the feasibility of the proposed motor.The maximal speed and torque of the prototype are tested to be 126 r/min and 0.8 N·m,respectively.

  7. Matlab- Based Simulation of Ultrasonic Motors%超声波电机稳态运行的建模和仿真

    Institute of Scientific and Technical Information of China (English)

    王付军

    2012-01-01

    研究超声波电机稳态运行的模型建立问题,由于传统电机稳态模型过于复杂和计算量大,影响超声波电机系统的性能优化.为解决上述问题,改善模型的复杂程度,提出用Kirchof薄板理论为基础,将超声波电机的定转子接触简化为一个二维弹性接触问题的方法来建模,并且用matlab进行软件仿真超声波电机模型.通过仿真获得的超声波电机的稳态运行数据,与实际测量值比较吻合的较好.实验证明,建立的模型简洁,计算时间短,为环形行波型超声波电机的进一步开发和性能优化提供了基础.%It studies the steady - state operation of the ultrasonic motor modeling problem. Since traditional motor steady - state model is too complex and large amount of computation, Affect the performance of ultrasonic motor system optimization. To solve these problems, Reduce the complexity of the model, Propose thatbased on Kirchof plate theory, using a way of the traveling wave ring type ultrasonic motor stator and rotor contact with simplified two - dimensional elastic contact problem to model. And simulation with matlab software model of the ultrasonic motor, operating data of ultrasonic motor by The model , consistent with the measured values better. Proved by experiments, the simulation model is simple, computing time is short, for the further development of the traveling wave ring type ultrasonic motor and performance optimization provide a basis.

  8. The study of volume ultrasonic waves propagation in the gas-containing iron ore pulp.

    Science.gov (United States)

    Morkun, V; Morkun, N; Pikilnyak, A

    2015-02-01

    The results of research of the volume ultrasonic waves propagation in the gas-containing iron ore slurry using ultrasonic phased array technology is presented. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Ultrasonic guided wave mechanics for composite material structural health monitoring

    Science.gov (United States)

    Gao, Huidong

    The ultrasonic guided wave based method is very promising for structural health monitoring of aging and modern aircraft. An understanding of wave mechanics becomes very critical for exploring the potential of this technology. However, the guided wave mechanics in complex structures, especially composite materials, are very challenging due to the nature of multi-layer, anisotropic, and viscoelastic behavior. The purpose of this thesis is to overcome the challenges and potentially take advantage of the complex wave mechanics for advanced sensor design and signal analysis. Guided wave mechanics is studied in three aspects, namely wave propagation, excitation, and damage sensing. A 16 layer quasi-isotropic composite with a [(0/45/90/-45)s]2 lay up sequence is used in our study. First, a hybrid semi-analytical finite element (SAFE) and global matrix method (GMM) is used to simulate guided wave propagation in composites. Fast and accurate simulation is achieved by using SAFE for dispersion curve generation and GMM for wave structure calculation. Secondly, the normal mode expansion (NME) technique is used for the first time to study the wave excitation characteristics in laminated composites. A clear and simple definition of wave excitability is put forward as a result of NME analysis. Source influence for guided wave excitation is plotted as amplitude on a frequency and phase velocity spectrum. This spectrum also provides a guideline for transducer design in guided wave excitation. The ultrasonic guided wave excitation characteristics in viscoelastic media are also studied for the first time using a modified normal mode expansion technique. Thirdly, a simple physically based feature is developed to estimate the guided wave sensitivity to damage in composites. Finally, a fuzzy logic decision program is developed to perform mode selection through a quantitative evaluation of the wave propagation, excitation and sensitivity features. Numerical simulation algorithms are

  10. Detection of laser generated ultrasonic wave using Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung Cho; Nakano, Hidetoshi [Japan National Research Laboratory of Metrology, Tokyo (Korea, Republic of); Jhang, Kyung Young [School of Mechanical Engineering, Seoul (Korea, Republic of)

    1999-05-15

    A stabilized Michelson Interferometer is proposed in order to detect the laser-generated ultrasonic waves in fee from the external noise such as low frequency mechanical vibration. In order to confirm the performance, theoretically expected waveforms were compared with experimentally detected ones in thermo-elastic region, where we generated ultrasonic wave in steel disk by using a Q-switched Nd:YAG laser. Also sound velocities of longitudinal and shear components were measured and they showed good agreement with the typical values in steel. Finally, the change of sound velocity according to the temperature change was measured to show that the proposed technique could be applied to the characterization of high temperature materials.

  11. 3D Ultrasonic Wave Simulations for Structural Health Monitoring

    Science.gov (United States)

    Campbell, Leckey Cara A/; Miler, Corey A.; Hinders, Mark K.

    2011-01-01

    Structural health monitoring (SHM) for the detection of damage in aerospace materials is an important area of research at NASA. Ultrasonic guided Lamb waves are a promising SHM damage detection technique since the waves can propagate long distances. For complicated flaw geometries experimental signals can be difficult to interpret. High performance computing can now handle full 3-dimensional (3D) simulations of elastic wave propagation in materials. We have developed and implemented parallel 3D elastodynamic finite integration technique (3D EFIT) code to investigate ultrasound scattering from flaws in materials. EFIT results have been compared to experimental data and the simulations provide unique insight into details of the wave behavior. This type of insight is useful for developing optimized experimental SHM techniques. 3D EFIT can also be expanded to model wave propagation and scattering in anisotropic composite materials.

  12. Fracture detection in crystalline rock using ultrasonic shear waves

    Energy Technology Data Exchange (ETDEWEB)

    Waters, K.H.; Palmer, S.P.; Farrell, W.E.

    1978-12-01

    An ultrasonic shear wave reflection profiling system for use in the detection of water-filled cracks occurring within a crystalline rock mass is being tested in a laboratory environment. Experiments were performed on an irregular tensile crack induced approximately 0.5 m below one circular face of a 1.0-m-dia, 1.8-m-long granite cylinder. Good reflection data were obtained from this irregular crack with the crack either air filled or water filled. Data were collected that suggest a frequency-dependent S/sub H/ wave reflection coefficient for a granite-water interface. Waves that propagate along the free surface of a rock mass (surface waves) can severely hinder the detection of reflected events. Two methods of reducing this surface wave noise were investigated. The first technique uses physical obstructions (such as a slit trench) to scatter the surface waves. The second technique uses a linear array of receivers located on the free surface to cancel waves that are propagating parallel to the array (e.g., surface waves), thus enhancing waves with propagation vectors orthogonal to the linear array (e.g., reflected events). Deconvolution processing was found to be another method useful in surface wave cancellation.

  13. Improvements in Controllability of Ultrasonic Linear Motors by Longitudinal-Bending Multilayered Transducers with Independent Electrodes

    Science.gov (United States)

    Takano, Masahiro; Hirosaki, Kenichi; Takimoto, Mikio; Ichimura, Satoru; Nakamura, Kentaro

    2011-07-01

    Ultrasonic motors are nonlinear in input-output characteristics, which causes problems for precise control. To obtain good controllability and realize low-cost fabrication, we proposed an ultrasonic linear motor using a multilayered transducer with independent electrode sets for the first longitudinal mode and the second bending mode. We can change the shape of the vibration locus at the friction head arbitrarily by independently controlling the amplitude and phase of each vibration component. Controllability in the proposed motor was investigated by changing the shape of the vibration locus. In the proposed motor, the nonlinear part of the input-output characteristics is suppressed to 1/20 of that in conventional ultrasonic motors. As a result, a good positioning resolution of 20 nm and a low-speed drive of 0.1 mm/s were obtained with a simple closed-loop control system.

  14. Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

    Energy Technology Data Exchange (ETDEWEB)

    Telschow, Kenneth Louis; Deason, Vance Albert; Datta, S.K.

    1999-05-01

    A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreement was obtained with modeling calculations of the phase velocity in all planar directions for an anisotropic sheet material. The approach functions with diffusely scattering surfaces, subnanometer motions and at frequencies from Hz to GHz.

  15. Dynamic Holographic Lock-In Imaging of Ultrasonic Waves

    Energy Technology Data Exchange (ETDEWEB)

    K. L. Telschow; S. K. Datta (University of Colorado); V. A. Deason (INEEL)

    1999-05-01

    A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of ultrasonic traveling wave surface displacement and phase in all planar directions simultaneously without scanning. The imaging method performs optical lock-in operation. A single antisymmetric Lamb wave mode image produces direct quantitative determination of the phase velocity in all planar directions showing plate stiffness anisotropy. Excellent agreement was obtained with modeling calculations of the phase velocity in all planar directions for an anisotropic sheet material. The approach functions with diffusely scattering surfaces, subnanometer motions and at frequencies from Hz to GHz.

  16. Influence of Friction Interface Contact on Ultrasonic Motor Efficiency Under Static Conditions

    Institute of Scientific and Technical Information of China (English)

    Zhang Yifeng; ZhangWu; XiaoAiwu; Zhu Meng; Pan Yunhua; Zhang Xiaoya

    2015-01-01

    The friction interface matching plays a deterministic role in the motor efficiency ,and the microcosmic contact status of friction interface should be investigated to improve the ultrasonic motor performance .The main purpose is to improve the effective output power of ultrasonic motor .Hence ,one studies the contact condition of the friction interface of the ultrasonic motor ,analyzes the micro condition of contact interface through finite ele-ment analysis ,optimizes unreasonable structures ,and compares the two different-structure ultrasonic motors through experiments .The results reflect the necessity of optimization .After optimization ,the stator and rotor de-form after pre-pressure and the contact interface of them full contact theoretically .When reaching heat balance the effective output of the motor is 37% ,and the average effective output efficiency is 2 .384 times higher than that of the unoptimized .It can be seen that the total consumption of the ultrasonic motor system decreases significantly . Therefore ,when using in certain system the consumption taken from the system will decreases largely ,especially in the system with a strict consumption control .

  17. A nut-type ultrasonic motor and its application in the focus system

    Institute of Scientific and Technical Information of China (English)

    ZHOU TieYing; ZHANG Yun; CHEN Yu; LU CunYue; FU DeYong; LI Yi; HU XiaoPing

    2009-01-01

    This article reports a screw-driven polyhedron linear ultrasonic motor (USM) of nut-type. It is comprised of a stator, which is a threaded metal nut bonded with piezoelectric plates on its external surface, and a rotor with external threads, which engage with the internal threads of the stator. A traveling wave in the plane is stimulated on the stator when harmonic electric signals are applied to the piezoelectric plates. The traveling wave drives the rotor to rotate, and the threads transform the rotation into a linear motion. The lens can be fixed in the rotor and realize the integrated design of the auto focus system. This structure can omit retarder and directly drive to obtain a high accuracy of positioning, and it is shock-proof. A mini AF cellular phone module (8.5 mm×8.5 mm×5.9 mm) driven by this motor was made and an image resolution of 3 5 MP was obtained in the module prototypes of the cellular phone.

  18. Ultrasonic linear motor using the L-B mode Langevin transducer with an exponential horn

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    An ultrasonic linear motor is proposed and fabricated by using the longitudinal and bending vibration double mode bolt-clamped Langevin type transducer to meet high power and speed requirements in the aerospace and semiconductor industries.The elliptical trajectory of the driving tip is formed by exciting the longitudinal and bending vibration with phase difference,which generates thrust force and normal force,respectively.An exponential shape horn is adopted to achieve a high linear speed.The classical theory of the transducer horn is used to determine the transducer's longitudinal resonance frequency and configuration dimensions.FEM analysis is used to degenerate the longitudinal and bending vibration resonant frequencies.The different locations of the driving tip on the horn cause different elliptical-shaped vibration trajectories,and how the trajectory's shape variation influences motor mechanical output is studied by using the FEM method.Simulation analysis and experiment results show that the motor has better performance when the driving tip is located at the antinode of the bending wave.Typical output of the prototype is no-load velocity of 480 mm/s and maximum driving force of 25 N.

  19. Phased array tuning for optimal ultrasonic guided wave mode selection

    Science.gov (United States)

    Bostron, J. H.; Rose, J. L.; Moose, C. A.

    2014-02-01

    Ultrasonic guided waves have become widely used in a variety of nondestructive evaluation applications due to their efficiency in defect detection, ability to inspect hidden areas, and other reasons. With a thorough understanding of guided wave mechanics, researchers can predict which guided wave modes will have a high probability of success in a particular nondestructive evaluation application. However, work continues to find optimal mode and frequency selection. An "optimal" mode could give the highest sensitivity to defects or the greatest penetration power, increasing inspection efficiency. In this work, we consider the use of guided interface waves for bond evaluation. A phased comb array transducer is used to sweep in the phase velocity - frequency space in an effort to determine optimal modes.

  20. Determination of Residual Stress in Composite Materials Using Ultrasonic Waves

    Science.gov (United States)

    Rokhlin, S. I.

    1997-01-01

    The performance of high temperature composites can be significantly affected by the presence of residual stresses. These stresses arise during cooling processes from fabrication to room temperature due to mismatch of thermal expansion coefficients between matrix and fiber materials. This effect is especially pronounced in metal matrix and intermetallic composites. It can lead to plastic deformations, matrix cracking and fiber/matrix interface debonding. In this work the feasibility of ultrasonic techniques for residual stress assessment in composites is addressed. A novel technique for absolute stress determination in orthotropic materials from angular dependencies of ultrasonic velocities is described. The technique is applicable for determination of both applied and residual stresses and does not require calibration measurements on a reference sample. The important advantage of this method is that stress is determined simultaneously with stress-dependent elastic constants and is thus decoupled from the material texture. It is demonstrated that when the principal plane stress directions coincide with acoustical axes, the angular velocity data in the plane perpendicular to the stress plane may be used to determine both stress components. When the stress is off the acoustical axes, the shear and the difference of the normal stress components may be determined from the angular dependence of group velocities in the plane of stresses. Synthetic sets of experimental data corresponding to materials with different anisotropy and stress levels are used to check the applicability of the technique. The method is also verified experimentally. A high precision ultrasonic wave transmission technique is developed to measure angular dependence of ultrasonic velocities. Examples of stress determination from experimental velocity data are given. A method is presented for determination of velocities of ultrasonic waves propagating through the composite material with residual

  1. A High Revolution Speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

    Institute of Scientific and Technical Information of China (English)

    YANG Bin; LIU Jing-Quan; CHEN Di; CAI Bing-Chu

    2005-01-01

    @@ A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque.

  2. FEM Simulations of Leaky Lamb Wave in Ultrasonic Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jin Ho; Joo, Young Sang; Kim, Jong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-05-15

    As the sodium coolant of a sodium-cooled fast reactor (SFR) is opaque to light, a conventional visual inspection cannot be used for carrying out an in-service inspection of the internal structures under a sodium level. An ultrasonic wave should be applied for an under-sodium viewing of the internal structures in a reactor vessel. Recently, a noble plate-type ultrasonic waveguide sensor has been developed for versatile applications in an under-sodium viewing application. The beam profile of a A{sub 0}-mode leaky Lamb wave of the waveguide sensor affects the resolution of visualization image in under-sodium viewing. In the design and manufacture of the waveguide sensor, the finite element method (FEM) modeling and simulation of the propagation of a leaky Lamb wave is required for the estimation and optimization of the waveguide sensor design parameters. In the previous research, the simple 2D modeling and simulation of the waveguide sensor had been carried out. In this work, FEM simulation of the propagation and radiation of the leaky Lamb wave in the waveguide sensor is performed for the vertical and lateral beam profile analysis using the pseudo 3D modeling including the wedge

  3. Behavior of ultrasonic waves in wood with presence of holes

    Directory of Open Access Journals (Sweden)

    Chiara Barros Secco

    2012-09-01

    Full Text Available This work aimed to analyze the pattern of variation in wave lengths in presence of wood holes and to develop a model capable of describing the process. To attain that end, wood pieces were used from species pequiá (Aspidosperma desmanthum, on which circular and linear artificial holes were made and gradually enlarged. Ultrasonic tests were performed using USLab equipment and 45 kHz transducers. Measurements were taken first on the intact piece and then after each stage of artificial hole enlargement. Results demonstrated that propagation velocities of ultrasonic waves are affected by presence of holes and also that reduction in velocity is caused by changes in wave path, since waves tend to deviate from empty space and travel through matter. The circular hole type had a slightly stronger influence on velocity reduction than the linear hole type. Variation in velocity as a function of increasing percentage of hollow space relative to the intact piece can be represented by a linear model.

  4. Study on self-tuning pole assignment speed control of an ultrasonic motor.

    Science.gov (United States)

    Shi, Jingzhuo; Bo, Liu; Yu, Zhang

    2011-10-01

    Ultrasonic motors have a heavy nonlinearity, which varies with driving conditions. The nonlinearity is a problem as an accurate motion actuator for industrial applications and it is important to eliminate the nonlinearity in order to improve the control performance. In general, complicated control strategies are used to deal with the nonlinearity of ultrasonic motors. This paper proposes a new speed control scheme for ultrasonic motors to overcome the nonlinearity employing a simplified self-tuning control. The speed control model which can reflect the main nonlinear characteristics is obtained using a system identification method based on the step response. Then, a pole assignment speed controller is designed. To avoid the influence of the motor's nonlinearity on the speed control performance, a control parameters' on-line self-tuning strategy utilizing the gain of the model is designed. The proposed control strategy is realized using a DSP circuit, and experiments prove the validity of the proposed speed control scheme.

  5. Fuzzy auto-tuning PID control of multiple joint robot driven by ultrasonic motors.

    Science.gov (United States)

    Sun, Zhijun; Xing, Rentao; Zhao, Chunsheng; Huang, Weiqing

    2007-11-01

    A three-joint robot is directly driven by ultrasonic motors with advantage of high torque at low speed. The speed of the ultrasonic motors is actually controlled by regulating their operating frequencies. The kinematic and kinetic analyses of the robot have been carried out using Adams. Due to the lack of accurate control model of ultrasonic motors and the time-varying motor parameters, a fuzzy auto-tuning proportional integral derivative (PID) controller for the robot is experimented, in which a simple method to tune parameters of the PID type fuzzy controller on-line is developed and a new position-speed feedback strategy is proposed and implemented. The effectiveness of the proposed control strategy and fuzzy logic controller is verified by experimental investigation.

  6. Cure monitoring using ultrasonic guided waves in wires.

    Science.gov (United States)

    Vogt, T; Lowe, M; Cawley, P

    2003-09-01

    The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated. The two techniques presented use a wire waveguide which is partly embedded in the resin. The first technique is based on the measurement of attenuation due to leakage of bulk waves into the resin surrounding the waveguide. The second technique measures the reflection of the guided wave that occurs at the point where the waveguide enters the resin. Both the attenuation and the reflection coefficient change significantly during cure, and the numerical methods to relate these to the material properties of the curing resin are presented in this paper. The results from the modeling are experimentally verified and show good agreement. The applicability of each testing method is discussed, and typical cure-monitoring curves are presented.

  7. Cure monitoring using ultrasonic guided waves in wires

    Science.gov (United States)

    Vogt, T.; Lowe, M.; Cawley, P.

    2003-09-01

    The possibility of using ultrasonic guided waves for monitoring the cure process of epoxy resins is investigated. The two techniques presented use a wire waveguide which is partly embedded in the resin. The first technique is based on the measurement of attenuation due to leakage of bulk waves into the resin surrounding the waveguide. The second technique measures the reflection of the guided wave that occurs at the point where the waveguide enters the resin. Both the attenuation and the reflection coefficient change significantly during cure, and the numerical methods to relate these to the material properties of the curing resin are presented in this paper. The results from the modeling are experimentally verified and show good agreement. The applicability of each testing method is discussed, and typical cure-monitoring curves are presented.

  8. Structural Design and Control of Variable Camber Wing Driven by Ultrasonic Motors

    Institute of Scientific and Technical Information of China (English)

    Liu Weidong; Zhu Hua; Zhou Shengqiang; Bai Yalei; Zhao Chunsheng

    2015-01-01

    A novel variable camber wing driven by ultrasonic motors is proposed .Key techniques of distributed lay-out of drive mechanisms ,coordination control of distributed ultrasonic motors as well as novel flexible skin under-going one-dimensional morphing are studied .The system integration of small variable camber wing is achieved . Distributed layout of parallelogram linkages driven by geared ultrasonic motors is adopted for morphing ,aimed at reducing the load for each motor and producing various aerodynamic configurations suitable for different flying states .Programmable system-on-chip (PSoC) is used to realize the coordination control of the distributed ultrason-ic motors .All the morphing driving systems are assembled in the interior of the wing .The wing surface is covered with a novel smooth flexible skin in order to maintain wing shape and decrease the aerodynamic drag during mor-phing .Wind tunnel test shows that the variable camber wing can realize morphing under low speed flight condi-tion .Lift and drag characteristics and aerodynamic efficiency of the wing are improved .Appropriate configurations can be selected to satisfy aerodynamic requirements of different flight conditions .The study provides a practical ap-plication of piezoelectric precision driving technology in flow control .

  9. A novel multi-degree-of-freedom thick-film ultrasonic motor.

    Science.gov (United States)

    Aoyagi, Manaba; Beeby, Steve P; White, Neil M

    2002-02-01

    This paper describes a new multi-degree-of-freedom (MDOF) ultrasonic motor that comprises few parts and is based on low-cost thick-film technology. Conventional ultrasonic motors using bulk lead zirconate titanate (PZT) or thin-film PZT layers are relatively expensive at the present time. Thick-film printed PZT technology provides the opportunity to reduce the costs of ultrasonic motors. To demonstrate the feasibility of this approach, an ultrasonic motor was fabricated from alumina using thick-film printed PZT actuators. The thick-film PZT and electrode layers were printed on a thin alumina plate, and a tiny cylinder was mounted at its center. This cylinder magnifies the lateral displacement of the stator, holds the spherical rotor, and transmits the driving force to the sphere. Three bending vibrations, B22, B30, B03, of the plate were applied to rotate the sphere. Sufficient displacements for rotating the sphere were obtained near the resonance of B22 by applying an excitation voltage of 200 V peak-to-peak via a three-phase drive circuit. Rotations in three orthogonal directions have been observed by controlling the phase of the driving signal to the PZT electrodes, and a MDOF ultrasonic motor was successfully realized.

  10. Ultrasonic guided wave nondestructive evaluation using generalized anisotropic interface waves

    Science.gov (United States)

    Gardner, Michael D.

    The motivation for this work is a goal to inspect interfaces between thick layers of materials that can be anisotropic. The specific application is a thick composite bonded to a metal substrate. The interface is inspected for disbonds between the metal and composite. The large thickness allows the problem to be modeled as a half space. The theory behind guided waves in plates is presented. This theory includes the calculation and analysis of dispersion curves and the resulting wave structure. It is noted that for high frequency-thickness values, certain modes will converge to the half-space waves, e.g. the Rayleigh wave and the Stoneley wave. Points of high energy, especially shear energy, at the interface are desirable for interfacial inspection. Therefore, the wave structure for all modes and frequencies is searched for ideal inspection points. Interface waves are inherently good modes to use for interface inspection. Results from the dispersion curves and wave structures are verified in the finite element model software package called Abaqus. It is confirmed that the group speeds and wave structures of the modes match the predicted values. A theoretical development of interface waves is given wherein Rayleigh, Stoneley, and generalized interface waves are discussed. This is applied to both isotropic and anisotropic materials. It is shown that the Stoneley wave only exists for a certain range of material parameters. Because the Stoneley wave is the interface wave between two solid half spaces, it might appear that only certain pairs of solids would allow for inspection via interface wave. However, it is shown that for perturbations of the Stoneley-wave-valid material properties, interface waves which leak energy away from the interface can still propagate. They can also be used for inspection. Certain choices of materials will leak less energy and will therefore allow for longer inspection distances. The solutions to the isotropic leaky wave problem exist on

  11. Experimental study of ultrasonic beam sectors for energy conversion into Lamb waves and Rayleigh waves.

    Science.gov (United States)

    Declercq, Nico Felicien

    2014-02-01

    When a bounded beam is incident on an immersed plate Lamb waves or Rayleigh waves can be generated. Because the amplitude of a bounded beam is not constant along its wave front, a specific beam profile is formed that influences the local efficiency of energy conversion of incident sound into Lamb waves or Rayleigh waves. Understanding this phenomenon is important for ultrasonic immersion experiments of objects because the quality of such experiments highly depends on the amount of energy transmitted into the object. This paper shows by means of experiments based on monochromatic Schlieren photography that the area within the bounded beam responsible for Lamb wave generation differs from that responsible for Rayleigh wave generation. Furthermore it provides experimental verification of an earlier numerical study concerning Rayleigh wave generation.

  12. A Traveling Wave Type of Piezoelectric Ultrasonic Bidirectional Linear Microactuator

    Science.gov (United States)

    Sun, Dongming; Wang, Sheng; Sakurai, Junpei; Hata, Seiichi; Choi, Kee-Bong; Shimokohbe, Akira

    2009-04-01

    A piezoelectric ultrasonic microactuator is presented, with a cylindrical stator and slider structure. The length and diameter of the microactuator are about 10 and 1.5 mm, respectively. The stator consists of two piezoelectric ceramic (PZT) tubes connected by a thin film metallic glass (TFMG) pipe, which is fabricated using the rotating magnetron sputtering technique. Traveling wave propagation is generated on the TFMG pipe in finite element method (FEM) simulations and also observed in the measurement. Bi-directional motion of the slider was observed around 600 kHz, and the maximum velocity was about 40 mm/s at 25 V.

  13. Properties of GH4169 Superalloy Characterized by Nonlinear Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Hongjuan Yan

    2015-01-01

    Full Text Available The nonlinear wave motion equation is solved by the perturbation method. The nonlinear ultrasonic coefficients β and δ are related to the fundamental and harmonic amplitudes. The nonlinear ultrasonic testing system is used to detect received signals during tensile testing and bending fatigue testing of GH4169 superalloy. The results show that the curves of nonlinear ultrasonic parameters as a function of tensile stress or fatigue life are approximately saddle. There are two stages in relationship curves of relative nonlinear coefficients β′ and δ′ versus stress and fatigue life. The relative nonlinear coefficients β′ and δ′ increase with tensile stress when tensile stress is lower than 65.8% of the yield strength, and they decrease with tensile stress when tensile stress is higher than 65.8% of the yield strength. The nonlinear coefficients have the extreme values at 53.3% of fatigue life. For the second order relative nonlinear coefficient β′, there is good agreement between the experimental data and the comprehensive model. For the third order relative nonlinear coefficient δ′, however, the experiment data does not accord with the theoretical model.

  14. Effect of Stress on Energy Flux Deviation of Ultrasonic Waves in Ultrasonic Waves in GR/EP Composites

    Science.gov (United States)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1990-01-01

    Ultrasonic waves suffer energy flux deviation in graphite/epoxy because of the large anisotropy. The angle of deviation is a function of the elastic coefficients. For nonlinear solids, these coefficients and thus the angle of deviation is a function of stress. Acoustoelastic theory was used to model the effect of stress on flux deviation for unidirectional T300/5208 using previously measured elastic coefficients. Computations were made for uniaxial stress along the x3 axis fiber axis) and the x1 axis for waves propagating in the x1x3 plane. These results predict a shift as large as three degrees for the quasi-transverse wave. The shift in energy flux offers new nondestructive technique of evaluating stress in composites.

  15. A piezoelectric linear ultrasonic motor with the structure of a circular cylindrical stator and slider

    Science.gov (United States)

    Sun, Dongming; Wang, Sheng; Sakurai, Junpei; Choi, Kee-Bong; Shimokohbe, Akira; Hata, Seiichi

    2010-04-01

    A piezoelectric linear ultrasonic motor is proposed, with a cylindrical stator and slider structure. The length and diameter of the motor are about 10 and 1.5 mm, respectively. The stator consists of two piezoelectric ceramic (PZT) tubes connected by a thin film metallic glass (TFMG) pipe. The stator is designed based on theoretical analyses and finite element method (FEM) simulation. The traveling wave propagation is obtained in the FEM simulation under the proper geometrical sizes, suitable boundary conditions and driving voltage signals. The trajectories of particles on the TFMG pipe are elliptical motion. In the experiment, a 25 µm thick TFMG pipe is fabricated using the rotating magnetron sputtering technique and the vibration characteristics of the stator are measured by a laser Doppler vibrometer (LDV) system. Bidirectional motion of the slider is observed around 600 kHz, the maximum velocity is near to 40 mm s - 1 at 50 Vp-p for the loose slider and the maximum output force is 6 mN at 70 Vp-p for the tight slider.

  16. Lamb Wave Technique for Ultrasonic Nonlinear Characterization in Elastic Plates

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Tae Hun; Kim, Chung Seok; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2010-10-15

    Since the acoustic nonlinearity is sensitive to the minute variation of material properties, the nonlinear ultrasonic technique(NUT) has been considered as a promising method to evaluate the material degradation or fatigue. However, there are certain limitations to apply the conventional NUT using the bulk wave to thin plates. In case of plates, the use of Lamb wave can be considered, however, the propagation characteristics of Lamb wave are completely different with the bulk wave, and thus the separate study for the nonlinearity of Lamb wave is required. For this work, this paper analyzed first the conditions of mode pair suitable for the practical application as well as for the cumulative propagation of quadratic harmonic frequency and summarized the result in for conditions: phase matching, non-zero power flux, group velocity matching, and non-zero out-of-plane displacement. Experimental results in aluminum plates showed that the amplitude of the secondary Lamb wave and nonlinear parameter grew up with increasing propagation distance at the mode pair satisfying the above all conditions and that the ration of nonlinear parameters measured in Al6061-T6 and Al1100-H15 was closed to the ratio of the absolute nonlinear parameters

  17. Can lubricant enhance the torque of ultrasonic motors? An experimental investigation

    Science.gov (United States)

    Qiu, Wei; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2014-12-01

    Lubrication has been proven to be an effective approach to drastically improve the efficiency of ultrasonic motors without losing the output torque. This phenomenon is attributed to the effective modulation of the friction force by lubricant, according to the theory described in the Stribeck curve. Previous findings even show a potential to increase the motor output torque with lubrication. Here, the torque enhancement of ultrasonic motors using lubricant is extensively studied in hybrid transducer-type ultrasonic motors (HTUSMs) with a size of 25 mm in diameter. The lubricated HTUSMs could withstand static preload as high as 267 N and maximum torque as large as 1.01 N m was obtained with lubrication, which were 3.5 times and 2.6 times higher than those in dry condition, respectively. This result clearly reveals that lubrication can enable ultrasonic motors to be operated under much higher static preload and hence significantly improve the motor output torque, instead of only reducing the friction force.

  18. Design of single-phase driven screw-thread-type ultrasonic motor

    Science.gov (United States)

    Chang, Lien-Kai; Tsai, Mi-Ching

    2016-05-01

    Most screw-thread-type ultrasonic motors are designed to be two-phase driven. This paper aims to present a novel single phase driven design that generates the required wobble motion, thus significantly simplifying the driving circuit of the ultrasonic motor. The proposed single-phase driven screw-thread-type ultrasonic motor works with two orthogonal bending modes generated by an asymmetric stator design. The novel stator design can improve the vibration displacement and further enhance the performance of the single phase driven motor. The vibration characteristics of the asymmetric stator structure were analyzed by ANSYS finite element analysis software. Based on the design and analysis processes, a prototype of the desired screw-thread-type ultrasonic motor was fabricated and tested. When the operating voltage is 200 Vpp, the obtained main characteristics of the proposed motor are as follows: the working frequency is between 28.3 and 29.5 kHz; the maximum no-load velocity is approximately 4.1 mm s-1; and the thrust force is 1.6 N.

  19. Monitoring early age cementitious materials using ultrasonic guided waves

    Science.gov (United States)

    Borgerson, Jacob L.

    The evaluation of early age concrete is critical for reducing construction times and ensuring quality. In this study, the use of ultrasonic guided waves for monitoring the development of early age cementitious materials is investigated. A torsional wave is transmitted and received through a waveguide that is embedded in early age mortar or concrete. As the cementitious material sets and hardens, the received wave(s) change, indicating the transition from a semifluid to a solid state. This thesis proposes two systems. The first system is a through-transmission system; a wave is transmitted on one end of an embedded waveguide using a sensor arrangement and then it is received on the opposite end of the rod with another sensor. This approach monitors the attenuation of the fundamental torsional wave mode, resulting from the leakage of energy from the cylindrical steel rod to the surrounding cementitious material. The evolution of the material's properties is related to the energy leakage or attenuation of the guided wave. The second system is a pulse-echo system; a wave is transmitted on one end of a partially embedded waveguide via a sensor arrangement that also receives the reflected signals. This approach monitors both the reflection from the end of the rod and the reflection from the point where the waveguide enters the material. The development of the cementitious material's mechanical properties is related to both the energy leaked into the surrounding material and the energy reflected at the point of entry. The ability of this method to only require access to one side of the specimen makes it attractive for monitoring early age cementitious materials in the field. Experiments were performed on mixtures with varying water-cement ratios (w/c = 0.40, 0.50, and 0.60), chemical admixtures (accelerant and retardant), mineral admixtures (silica fume and fly ash), and coarse aggregate (pea gravel). The time of setting and compressive strength of the various mixtures

  20. Ultrasonic Rotary Motors Using Complex Transverse and Torsional Vibration Rods and Multiple Longitudinal Vibration Transducers

    Science.gov (United States)

    Suzuki, Atsuyuki; Kihara, Masaki; Katsumata, Yasuhiro; Ishii, Keisuke; Tsujino, Jiromaru

    2005-06-01

    The vibration and load characteristics of ultrasonic motors having (a) a torsional vibration cylinder with three bolt-clamped Langevin piezoelectric ceramic (PZT) longitudinal vibration transducers (BLTs) installed in the tangential direction and (b) a longitudinal vibration disk with three BLT transducers installed around a circular disk were studied. The center rod vibrates longitudinally and affects the load characteristics of the ultrasonic motor. Vibration distributions along a center rod were measured using a laser Doppler vibrometer. Revolution, electric input power, mechanical output power and efficiency were measured under various rotating torques. Maximum torque, revolution and efficiency of the ultrasonic motor with (a) a torsional vibration cylinder (a) were 0.75 Nm, 205 rpm and 1.68%, respectively, and (b) 0.32 Nm, 84 rpm and 1.68%, respectively, with a circular longitudinal vibration disk.

  1. Precision control system of two-DOF stage with linear ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    Hanlei ZHANG; Yunlai SHI; Chunsheng ZHAO

    2008-01-01

    Using an appropriate control method, linear ultrasonic motors can be used in applications requiring high position accuracy. In this paper, a closed loop PI control system is designed to achieve high position accu-racy during the control of a two-DOF stage driven by linear ultrasonic motors, Two ultrasonic motors are mounted on the stage to generate motion in two ortho-gonal directions. The PI control algorithm is used to increase the stability and accuracy of position control. The x-axis mover covers 30 mm forward and backward in less than 0.3 s settling time and the y-axis mover in less than 0.4 s. Experimental results denote that the control strategy proposed in this paper appears to have high effi-ciency, quick response, and high accuracy.

  2. A square-plate ultrasonic linear motor operating in two orthogonal first bending modes.

    Science.gov (United States)

    Chen, Zhijiang; Li, Xiaotian; Chen, Jianguo; Dong, Shuxiang

    2013-01-01

    A novel square-plate piezoelectric ultrasonic linear motor operated in two orthogonal first bending vibration modes (B₁) is proposed. The piezoelectric vibrator of the linear motor is simply made of a single PZT ceramic plate (sizes: 15 x 15 x 2 mm) and poled in its thickness direction. The top surface electrode of the square ceramic plate was divided into four active areas along its two diagonal lines for exciting two orthogonal B₁ modes. The achieved driving force and speed from the linear motor are 1.8 N and 230 mm/s, respectively, under one pair orthogonal voltage drive of 150 V(p-p) at the resonance frequency of 92 kHz. The proposed linear motor has advantages over conventional ultrasonic linear motors, such as relatively larger driving force, very simple working mode and structure, and low fabrication cost.

  3. Ultrasonic wave-based defect localization using probabilistic modeling

    Science.gov (United States)

    Todd, M. D.; Flynn, E. B.; Wilcox, P. D.; Drinkwater, B. W.; Croxford, A. J.; Kessler, S.

    2012-05-01

    This work presents a new approach rooted in maximum likelihood estimation for defect localization in sparse array guided wave ultrasonic interrogation applications. The approach constructs a minimally-informed statistical model of the guided wave process, where unknown or uncertain model parameters are assigned non-informative Bayesian prior distributions and integrated out of the a posteriori probability calculation. The premise of this localization approach is straightforward: the most likely defect location is the point on the structure with the maximum a posteriori probability of actually being the location of damage (i.e., the most probable location given a set of sensor measurements). The proposed approach is tested on a complex stiffened panel against other common localization approaches and found to have superior performance in all cases.

  4. Ultrasonic Guided Wave Propagation through Welded Lap Joints

    Directory of Open Access Journals (Sweden)

    Audrius Jankauskas

    2016-12-01

    Full Text Available The objective of the research presented here is the investigation of ultrasonic guided wave (UGW propagation through the lap joint welded plates used in the construction of a storage tank floors. The investigations have been performed using numerical simulation by finite element method (FEM and tested by measurement of the transmission losses of the guided waves transmitted through the welded lap joints. Propagation of the symmetric S0 mode in the welded stainless steel plates in the cases of different lap joint overlap width, operation frequency, and additional plate bonding caused by corrosion were investigated. It was shown that the transmission losses of the S0 mode can vary in the range of 2 dB to 8 dB depending on the ratio between lap joint width and wavelength. It was also demonstrated that additional bonding in the overlap zone caused by corrosion can essentially reduce transmission losses.

  5. Ultrasonic wave's interaction at fluid-porous piezoelectric layered interface.

    Science.gov (United States)

    Vashishth, Anil K; Gupta, Vishakha

    2013-02-01

    The complete description of acoustic propagation in a multilayered system is of great interest in a variety of applications such as non-destructive evaluation and acoustic design and there is need for a flexible model that can describe the reflection and transmission of ultrasonic waves in these media. The reflection and transmission of ultrasonic waves from a fluid loaded porous piezoelectric layered structure is studied analytically. The layered structure is considered to be consisting of n number of layers of porous piezoelectric materials. Transfer matrix technique is used to study the layered materials. The analytical expressions for the reflected, transmitted, interaction energy ratios and surface impedance are obtained. The effects of frequency, porosity, angle of incidence, layer thickness and number of layers on the energy ratios and surface impedance are studied for different configurations of the layered materials. The results obtained are deduced for the poro-elastic and fluid loaded porous piezoelectric half space case, which are in agreement with earlier established results. A comparison of the results, obtained by alternate numerical techniques, is made.

  6. 大力矩超声电机%High torque ultrasonic motors

    Institute of Scientific and Technical Information of China (English)

    杨淇; 杨明; 阙沛文

    2001-01-01

    本文综述了大力矩超声电机的应用和研究现状,分析了国内外大力矩超声电机实现的关键问题,展望了大力矩超声电机的应用前景.%This paper reviews the present status of the research and application about the high torque ultrasonic motor. The key factors to realize high torque of ultrasonic motor are analyzed. At last, the development trend is prospected.

  7. Assessment of fatigue damage in solid plates through the ultrasonic Lamb wave approach

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Changes(degradations) in the mechanical properties of solid plates induced by cyclic fatigue loading will influence the features of ultrasonic Lamb wave propagation,such as dispersion and attenuation.This paper has qualitatively analyzed the feasibility of using the amplitude-frequency characteristics and the stress wave factors(SWFs) of ultrasonic Lamb wave propagation to assess fatigue damage in solid plates.Liquid wedge transducers located on the surface of solid plates tested are used to generate and detect the Lamb wave signals.Based on the Ritec-SNAP ultrasonic measurement system,the experimental setup for assessing the degree of fatigue damage in solid plates using ultrasonic Lamb wave approach has been established.For several rolled aluminum sheets subjected to tension-tension cyclic loading,the experimental examinations have been performed for the relationships between the amplitude-frequency characteristics of ultrasonic Lamb wave propagation and the numbers of loading cycles(denoted by N),as well as the correlations between the Lamb wave SWFs and N.The experimental results show that the Lamb wave SWFs decrease monotonously and sensitively with the increment of cycles of fatigue loading.Based on the correlations between the Lamb wave SWFs and N,it is further verified that ultrasonic Lamb wave propagation combined with the Lamb wave SWFs can be used to effectively assess early fatigue damage in solid plates.

  8. SAMCEF在超声波电机设计中的应用%SAMCEF application in the design of ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    刘德华; 任一峰; 罗威

    2014-01-01

    Aiming at obtaining the ultrasonic motor vibration mode and harmonic response characteristics,SAMCEF finite element method(FEM)software was used to analyze stator vibration state of a ring-type traveling wave ultrasonic motor with 50mm in diameter.Based on modeling of the ultrasonic motor stator vibration mode was analyzed and optimum vibration mode was selected,and harmonic analysis was analyzed near the optimum vibration mode.The results indicate that SAMCEF is an effective method in the ultrasonic motor analysis.%在微机电领域中,为获得超声波电机的振动模态及谐响应特性,利用SAMCEF有限元分析软件对直径为50 mm的环形行波型超声波电机压电转换器和定子的振动状态进行了分析;在完成超声波电机定子建模的基础上,进行振动模态分析和最优模态选择,并在此基础上进行了谐响应分析。分析结果表明,利用SAMCEF软件对超声波电机进行分析被证明是一种行之有效的方法。

  9. Propagation characteristics of ultrasonic guided waves in continuously welded rail

    Science.gov (United States)

    Yao, Wenqing; Sheng, Fuwei; Wei, Xiaoyuan; Zhang, Lei; Yang, Yuan

    2017-07-01

    Rail defects cause numerous railway accidents. Trains are derailed and serious consequences often occur. Compared to traditional bulk wave testing, ultrasonic guided waves (UGWs) can provide larger monitoring ranges and complete coverage of the waveguide cross-section. These advantages are of significant importance for the non-destructive testing (NDT) of the continuously welded rail, and the technique is therefore widely used in high-speed railways. UGWs in continuous welded rail (CWR) and their propagation characteristics have been discussed in this paper. Finite element methods (FEMs) were used to accomplish a vibration modal analysis, which is extended by a subsequent dispersion analysis. Wave structure features were illustrated by displacement profiles. It was concluded that guided waves have the ability to detect defects in the rail via choice of proper mode and frequency. Additionally, thermal conduction that is caused by temperature variation in the rail is added into modeling and simulation. The results indicated that unbalanced thermal distribution may lead to the attenuation of UGWs in the rail.

  10. Temperature effects in ultrasonic Lamb wave structural health monitoring systems.

    Science.gov (United States)

    Lanza di Scalea, Francesco; Salamone, Salvatore

    2008-07-01

    There is a need to better understand the effect of temperature changes on the response of ultrasonic guided-wave pitch-catch systems used for structural health monitoring. A model is proposed to account for all relevant temperature-dependent parameters of a pitch-catch system on an isotropic plate, including the actuator-plate and plate-sensor interactions through shear-lag behavior, the piezoelectric and dielectric permittivity properties of the transducers, and the Lamb wave dispersion properties of the substrate plate. The model is used to predict the S(0) and A(0) response spectra in aluminum plates for the temperature range of -40-+60 degrees C, which accounts for normal aircraft operations. The transducers examined are monolithic PZT-5A [PZT denotes Pb(Zr-Ti)O3] patches and flexible macrofiber composite type P1 patches. The study shows substantial changes in Lamb wave amplitude response caused solely by temperature excursions. It is also shown that, for the transducers considered, the response amplitude changes follow two opposite trends below and above ambient temperature (20 degrees C), respectively. These results can provide a basis for the compensation of temperature effects in guided-wave damage detection systems.

  11. Microstructure Effects of Ultrasonic Waves in a Fiber Reinforced Composite Plate

    Institute of Scientific and Technical Information of China (English)

    HAN Jun-Bo; TANG Li-Guo; CHENG Jian-Chun; Yves Berthelot

    2000-01-01

    The microstructure effect of ultrasonic waves in a unidirectional titanium graphite composite is analyzed by the mode energy conversions of the laser-generated ultrasonic Lamb wvaves. The carrying energy of each mode in the Lamb wvaves is calculated quantitatively by the time-frequency filtering technique of the Wigner distribution. We found that the energy conversions among modes have happened in the process of propagation of ultrasonic Lamb wave. These energy conversions are attributed to microstructure scattering of ultrasonic wave by the fibers in a fiber reinforced composite material. This work will provide a quantitative method of ultrasonic characterizationof microstructure feature of the composite materials by the laser-generated Lamb wave technique.

  12. Improved ultrasonic TV images achieved by use of Lamb-wave orientation technique

    Science.gov (United States)

    Berger, H.

    1967-01-01

    Lamb-wave sample orientation technique minimizes the interference from standing waves in continuous wave ultrasonic television imaging techniques used with thin metallic samples. The sample under investigation is oriented such that the wave incident upon it is not normal, but slightly angled.

  13. Study on the Vibration Displacement Distribution of a Circular Ultrasonic Motor Stator

    CERN Document Server

    Ri, Chol-Su; Kim, Chol-Su; Im, Song-Jin

    2014-01-01

    In this paper is presented a theoretical consideration on the stator's displacement distribution, which is one of the most important problems in defining the structure of the circular ultrasonic motor stator. The results are compared with results obtained utilizing holographic interferometer, laser vibrometer and a FEM (finite element method) simulation. They are in a good agreement with each other.

  14. Ultrasonic phased array with surface acoustic wave for imaging cracks

    Science.gov (United States)

    Ohara, Yoshikazu; Oshiumi, Taro; Nakajima, Hiromichi; Yamanaka, Kazushi; Wu, Xiaoyang; Uchimoto, Tetsuya; Takagi, Toshiyuki; Tsuji, Toshihiro; Mihara, Tsuyoshi

    2017-06-01

    To accurately measure crack lengths, we developed a real-time surface imaging method (SAW PA) combining an ultrasonic phased array (PA) with a surface acoustic wave (SAW). SAW PA using a Rayleigh wave with a high sensitivity to surface defects was implemented for contact testing using a wedge with the third critical angle that allows the Rayleigh wave to be generated. Here, to realize high sensitivity imaging, SAW PA was optimized in terms of the wedge and the imaging area. The improved SAW PA was experimentally demonstrated using a fatigue crack specimen made of an aluminum alloy. For further verification in more realistic specimens, SAW PA was applied to stainless-steel specimens with a fatigue crack and stress corrosion cracks (SCCs). The fatigue crack was visualized with a high signal-to-noise ratio (SNR) and its length was measured with a high accuracy of better than 1 mm. The SCCs generated in the heat-affected zones (HAZs) of a weld were successfully visualized with a satisfactory SNR, although responses at coarse grains appeared throughout the imaging area. The SCC lengths were accurately measured. The imaging results also precisely showed complicated distributions of SCCs, which were in excellent agreement with the optically observed distributions.

  15. 预应力对超声电机定子振动影响分析%Affect of Pre-pressure on Ultrasonic Motor Stator Vibration

    Institute of Scientific and Technical Information of China (English)

    张炜; 李胤; 杨正伟; 王渭平; 田干

    2014-01-01

    For disclosing the effects of pre-pressure on stator vibration to analyse ultrasonic motor output per-fotmance more accurately , this paper , aiming to a given ring-type traveling wave ultrasonic motor , studied ultrasonic motor stator mode analyse in double-state with pre-pressure and non-pre-pressure , mainly analysed the affects of pre-pressure on inherent frequency , amplitude of ultrasonic motor stator vibration , and presen-ted mode hallmark differentiate principle to study the affects of prepressure on mode mixing.Results shows that pre-pressure can increase ultrasonic motor stator inherent frequency , amplitude and avoid mode mixing availably.%为揭示预应力对超声电机定子振动特性的影响,准确分析电机的输出性能,对行波旋转型超声电机定子结构在有、无预应力两种状态下进行了模态分析,研究了预应力对超声电机定子振动固有频率和振幅的影响,提出了模态“纯”度的判别标准,分析了预应力对模态混叠的影响。结果表明:预应力增加了超声电机定子振动的固有频率,增大了定子振动的振幅,能够有效抑制电机模态混叠现象。

  16. Analysis of a disk-type piezoelectric ultrasonic motor using impedance matrices.

    Science.gov (United States)

    Kim, Young H; Ha, Sung K

    2003-12-01

    The dynamic behavior and the performance characteristics of the disk-type traveling wave piezoelectric ultrasonic motors (USM) are analyzed using impedance matrices. The stator is divided into three coupled subsystems: an inner metal disk, a piezoelectric annular actuator with segmented electrodes, and an outer metal disk with teeth. The effects of both shear deformation and rotary inertia are taken into account in deriving an impedance matrix for the piezoelectric actuator. The impedance matrices for each subsystem then are combined into a global impedance matrix using continuity conditions at the interfaces. A comparison is made between the impedance matrix model and the three-dimensional finite element model of the piezoelectric stator, obtaining the resonance and antiresonance frequencies and the effective electromechanical coupling factors versus circumferential mode numbers. Using the calculated resonance frequency and the vibration modes for the stator and a brush model with the Coulomb friction for the stator and rotor contact, stall torque, and no-load speed versus excitation frequencies are calculated at different preloads. Performance characteristics such as speed-torque curve and the output efficiency of the USM also are estimated using the current impedance matrix and the contact model. The present impedance model can be shown to be very effective in the design of the USM.

  17. Rotating bouncing disks, tossing pizza dough, and the behavior of ultrasonic motors.

    Science.gov (United States)

    Liu, Kuang-Chen; Friend, James; Yeo, Leslie

    2009-10-01

    Pizza tossing and certain forms of standing-wave ultrasonic motors (SWUMs) share a similar process for converting reciprocating input into continuous rotary motion. We show that the key features of this motion conversion process such as collision, separation and friction coupling are captured by the dynamics of a disk bouncing on a vibrating platform. The model shows that the linear or helical hand motions commonly used by pizza chefs and dough-toss performers for single tosses maximize energy efficiency and the dough's airborne rotational speed; on the other hand, the semielliptical hand motions used for multiple tosses make it easier to maintain dough rotation at the maximum speed. The system's bifurcation diagram and basins of attraction also provide a physical basis for understanding the peculiar behavior of SWUMs and provide a means to design them. The model is able to explain the apparently chaotic oscillations that occur in SWUMs and predict the observed trends in steady-state speed and stall torque as preload is increased.

  18. Rotating bouncing disks, tossing pizza dough, and the behavior of ultrasonic motors

    Science.gov (United States)

    Liu, Kuang-Chen; Friend, James; Yeo, Leslie

    2009-10-01

    Pizza tossing and certain forms of standing-wave ultrasonic motors (SWUMs) share a similar process for converting reciprocating input into continuous rotary motion. We show that the key features of this motion conversion process such as collision, separation and friction coupling are captured by the dynamics of a disk bouncing on a vibrating platform. The model shows that the linear or helical hand motions commonly used by pizza chefs and dough-toss performers for single tosses maximize energy efficiency and the dough’s airborne rotational speed; on the other hand, the semielliptical hand motions used for multiple tosses make it easier to maintain dough rotation at the maximum speed. The system’s bifurcation diagram and basins of attraction also provide a physical basis for understanding the peculiar behavior of SWUMs and provide a means to design them. The model is able to explain the apparently chaotic oscillations that occur in SWUMs and predict the observed trends in steady-state speed and stall torque as preload is increased.

  19. Measurement of low-frequency ultrasonic wave in water using an acoustic fiber sensor.

    Science.gov (United States)

    Sakoda, Tatsuya; Sonoda, Yoshito

    2006-04-01

    An acoustic fiber sensor for measurement of ultrasonic waves, which used the approximate Raman-Nath diffraction effect where light diffraction waves were generated in an optical fiber by strain due to the ultrasonic waves, was proposed and examined. In order to characterize the acoustic fiber sensor as a basic study, measurements of low-frequency ultrasonic waves in water were examined using a step index fiber operating as a detection sensor. The results showed that characteristics of detected signals agreed with the theoretical prediction based on Fraunhofer diffraction. This indicates that our proposed fiber sensor can be used for the detection of low-frequency ultrasonic waves as well as the transmission of light diffraction signals.

  20. Mass transfer enhancement for LiBr solution using ultrasonic wave

    Institute of Scientific and Technical Information of China (English)

    韩晓东; 张仕伟; 汤勇; 袁伟; 李斌

    2016-01-01

    The methods were studied to improve the cooling performance of the absorption refrigeration system (ARS) driven by low-grade solar energy with ultrasonic wave, while the mechanism of ultrasonic wave strengthening boiling mass transfer in LiBr solution was also analyzed with experiment. The experimental results indicate that, under the driving heat source of 60–100 ºC and the ultrasonic power of 20–60 W, the mass flux of cryogen water in LiBr solution is higher after the application of ultrasonic wave than auxiliary heating with electric rod of the same power, so the ultrasonic application effectively enhances the heat utilization efficiency. The distanceH from ultrasonic transducer to vapor/liquid interface significantly affects mass transfer enhancement, so an optimalHoptcorresponding to certain ultrasonic power is beneficial to reaching the best strengthening effect for ultrasonic mass transfer. When the ultrasonic power increases, the mass transfer obviously speeds up in the cryogen water; however, as the power increases to a certain extent, the flux reaches a plateau without obvious increment. Moreover, the ultrasound-enhanced mass transfer technology can reduce the minimum temperature of driving heat source required by ARS and promote the application of solar energy during absorption refrigeration.

  1. Modeling and experimental validation of a linear ultrasonic motor considering rough surface contact

    Science.gov (United States)

    Lv, Qibao; Yao, Zhiyuan; Li, Xiang

    2017-04-01

    Linear ultrasonic motor is driven by the interface friction between the stator and the slider. The performance of the motor is significantly affected by the contact state between the stator and slider which depends considerably on the morphology of the contact interface. A novel fiction model is developed to evaluate the output characteristics of a linear ultrasonic motor. The proposed model, where the roughness and plastic deformation of contact surfaces are considered, differs from the previous spring model. Based on the developed model, the effects of surface roughness parameters on motor performance are investigated. The behavior of the force transmission between the stator and the slider is studied to understand the driving mechanism. Furthermore, a comparison between the proposed model and the spring model is made. An experiment is designed to verify the feasibility and effectiveness of this proposed model by comparing the simulation results with the measured one. The results show that the proposed model is more accurate than the spring model. These discussions will be very useful for the improvement of control and the optimal design of linear ultrasonic motor.

  2. Modal disturbance investigation of rod-shaped ultrasonic motor using bending vibrations

    Institute of Scientific and Technical Information of China (English)

    Jiantao ZHANG; Hua ZHU; Chunsheng ZHAO

    2008-01-01

    Modal disturbance of a rod-shaped ultrasonic motor using bending vibrations can cause problems such as low motor efficiency, instability, and poor control. In this paper, a dynamic analysis model of a stator is cre-ated on the basis of the finite element method (FEM) and Hamilton principle. The modal frequency sensitiv-ities of the stator to the structure parameters are inves-tigated by modal analysis. Accordingly, the structure parameters of the stator are modified to separate working modes from disturbance modes. A rod-shaped ultrasonic motor stator is fabricated, and the experi-mental results of its amplitude frequency response char-acteristics show that the purpose of modal separation is achieved. The frequency separation between working modes and disturbance modes is more than 2 kHz. The validity of the method is verified.

  3. Characteristics of Ultrasonic Linear Motor that Incorporates Two Transducers at an Acute Angle

    Science.gov (United States)

    Suzuki, Atsuyuki; Tsunoji, Masaki; Tsujino, Jiromaru

    2013-07-01

    In this study, we have developed an ultrasonic linear motor that incorporates two transducers at an acute angle. The two transducers are used to generate the vertical and horizontal vibration components. The complex vibration is excited using two electrical sources with a phase shift. Ultrasonic motors have unique characteristics such as silent motion and absence of magnetic noise. These characteristics are suitable for use in hospitals and so on. Therefore, we focus on developing actuators for use in a medical bed, specifically a bedsore prevention bed. A study of the vibration characteristics of the motor showed that the resonant frequencies of the transducers were appropriate, although the vibration amplitude of one transducer was less than that of the other. A study of the load characteristics showed that a no-load speed of 267 mm/s and a maximum thrust of 40 N were obtained.

  4. Efficiency improvement of hybrid transducer-type ultrasonic motor using lubricant.

    Science.gov (United States)

    Qiu, Wei; Mizuno, Yosuke; Koyama, Daisuke; Nakamura, Kentaro

    2013-04-01

    Ultrasonic motors have hit a bottleneck caused by low efficiency and short life, which limits their applications to some niche areas. We believe that lubrication is a promising candidate to solve these problems. In this paper, we clarify, both analytically and experimentally, that the performance of the hybrid transducer-type ultrasonic motor (HTUSM), including the transduction efficiency, can be drastically improved at large static preloads if appropriate lubricant is applied. First, simulation was performed using an equivalent circuit in dry and lubricated conditions, and the HTUSM characteristics were shown to be more desirable at high static preloads in the lubricated condition than in the dry condition. Then, we experimentally investigated the mechanical performance of the HTUSM, verifying the effect of improving the motor performance at high preloads using lubricant, which was in good agreement with the simulation results. The maximum transduction efficiency of the HTUSM was significantly enhanced from 28% in the dry condition to 68% in the lubricated condition.

  5. Non-collinear wave mixing for non-linear ultrasonic detection of physical ageing in PVC

    NARCIS (Netherlands)

    Demcenko, A.; Akkerman, Remko; Nagy, P.B.; Loendersloot, Richard

    2012-01-01

    This work considers the characterization of linear PVC acoustic properties using a linear ultrasonic measurement technique and the non-collinear ultrasonic wave mixing technique for measurement of the physical ageing state in PVC. The immersion pulse-echo measurements were used to evaluate phase

  6. Ultrasonic wave propagation in thermoviscous moving fluid confined by heating pipeline and flow measurement performance.

    Science.gov (United States)

    Chen, Yong; Huang, Yiyong; Chen, Xiaoqian

    2013-09-01

    Ultrasonic wave propagation in thermoviscous fluid with pipeline shear mean flow in the presence of a temperature gradient is investigated. On the assumption of irrotational and axisymmetric wave propagation, a mathematical formulation of the convected wave equation is proposed without simplification in the manner of Zwikker and Kosten. A method based on the Fourier-Bessel theory, which is complete and orthogonal in Lebesgue space, is introduced to convert the wave equations into homogeneous algebraic equations. Then numerical calculation of the axial wavenumber is presented. In the end, wave attenuation in laminar and turbulent flow is numerically studied. Meanwhile measurement performance of an ultrasonic flow meter is parametrically analyzed.

  7. Ultrasonic wave-based structural health monitoring embedded instrument

    Energy Technology Data Exchange (ETDEWEB)

    Aranguren, G.; Monje, P. M., E-mail: pedromaria.monje@ehu.es [Electronic Design Group, Faculty of Engineering of Bilbao, University of the Basque Country, Bilbao (Spain); Cokonaj, Valerijan [AERnnova Engineering Solutions Ibérica S.A., Madrid (Spain); Barrera, Eduardo; Ruiz, Mariano [Instrumentation and Applied Acoustic Research Group of the Technical University of Madrid, Madrid (Spain)

    2013-12-15

    Piezoelectric sensors and actuators are the bridge between electronic and mechanical systems in structures. This type of sensor is a key element in the integrity monitoring of aeronautic structures, bridges, pressure vessels, wind turbine blades, and gas pipelines. In this paper, an all-in-one system for Structural Health Monitoring (SHM) based on ultrasonic waves is presented, called Phased Array Monitoring for Enhanced Life Assessment. This integrated instrument is able to generate excitation signals that are sent through piezoelectric actuators, acquire the received signals in the piezoelectric sensors, and carry out signal processing to check the health of structures. To accomplish this task, the instrument uses a piezoelectric phased-array transducer that performs the actuation and sensing of the signals. The flexibility and strength of the instrument allow the user to develop and implement a substantial part of the SHM technique using Lamb waves. The entire system is controlled using configuration software and has been validated through functional, electrical loading, mechanical loading, and thermal loading resistance tests.

  8. Ultrasonic wave-based structural health monitoring embedded instrument.

    Science.gov (United States)

    Aranguren, G; Monje, P M; Cokonaj, Valerijan; Barrera, Eduardo; Ruiz, Mariano

    2013-12-01

    Piezoelectric sensors and actuators are the bridge between electronic and mechanical systems in structures. This type of sensor is a key element in the integrity monitoring of aeronautic structures, bridges, pressure vessels, wind turbine blades, and gas pipelines. In this paper, an all-in-one system for Structural Health Monitoring (SHM) based on ultrasonic waves is presented, called Phased Array Monitoring for Enhanced Life Assessment. This integrated instrument is able to generate excitation signals that are sent through piezoelectric actuators, acquire the received signals in the piezoelectric sensors, and carry out signal processing to check the health of structures. To accomplish this task, the instrument uses a piezoelectric phased-array transducer that performs the actuation and sensing of the signals. The flexibility and strength of the instrument allow the user to develop and implement a substantial part of the SHM technique using Lamb waves. The entire system is controlled using configuration software and has been validated through functional, electrical loading, mechanical loading, and thermal loading resistance tests.

  9. Ultrasonic Guided Wave Simulation Toolbox for Virtual Inspection of Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrasonic guided wave nondestructive evaluation (NDE) techniques are being used to detect flaws and damage in fracture critical structures such as composites. In...

  10. The development of radiation hardened robot for nuclear facility - Development of ultrasonic motor for driving robot hand

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Soo Hyun; Yoon, S. Y.; Maeng, I. J. [Dongguk University, Seoul (Korea)

    2000-04-01

    The camera types of variable form were used a wide field. For example, industry, broadcasting, homemaking, a dilettantes life, etc. But most of important components are imported because of the underdeveloped the interior technique. In a environment as special as atomic energy field, specially the performance of a ultrasonic motor and effect of Nuclear Facility are better than an electromagnetic motor. In our study, Manufacture and characteristics estimation of ring type piezoelectric ceramics, stator analysis and manufacture for ring type ultrasonic motor, implementation of ring type ultrasonic motor, development of driving circuit for ring type ultrasonic motor were carried out. On the basis of result, to stator design of ultrasonic motor for driving robot hand, resonance mode, resonance frequency and dispacement were analyzed using FEM program(ATILA). on the basis of this result optimum reason of stator for driving robot hand was established, and stator of ultrasonic motor for driving robot hand was designed and made. 24 refs., 55 figs., 4 tabs. (Author)

  11. Time-frequency analysis of guided ultrasonic waves used for assessing integrity of rock bolts

    Science.gov (United States)

    Stepinski, Tadeusz

    2017-04-01

    The purpose of this paper is to demonstrate application of the time-frequency analysis (TFA) for processing guided ultrasonic waves measured by means of a specially designed ultrasonic rock bolt tester during nondestructive inspection of rock bolts. A pulse-echo method is adopted in the instrument as the most appropriate for the in-field applications. This paper presents methods for analysis of the measured guided ultrasonic waves using the TFA. The proposed TFA methodology is first demonstrated on the simulated signals and then verified using the experimental signals gathered from grouted prepared rock bolts provided with artificial defects simulating grout discontinuities.

  12. Effective isolation of primo vessels in lymph using sound- and ultrasonic-wave stimulation.

    Science.gov (United States)

    Park, Do-Young; Lee, Hye-Rie; Rho, Min-Suk; Lee, Sang-Suk

    2014-12-01

    The effects of stimulation with sound and ultrasonic waves of a specific bandwidth on the microdissection of primo vessels in lymphatic vessels of rabbit were investigated. The primo vessels stained with alcian-blue dye injected in the lymph nodes were definitely visualized and more easily isolated by sound-wave vibration and ultrasonic stimulation applied to rabbits at various frequencies and intensities. With sound wave at 7 Hz and ultrasonic waves at 2 MHz, the probability of detecting the primo vessels was improved to 90%; however, without wave stimulation the probability of discovering primo vessels was about 50% only. Sound and ultrasonic waves at specific frequency bands should be effective for microdissection of the primo vessels in the abdominal lymph of rabbit. We suggest that oscillation of the primo vessels by sound and ultrasonic waves may be useful to visualize specific primo structure, and wave vibration can be a very supportive process for observation and isolation of the primo vessels of rabbits.

  13. Wave Mode Discrimination of Coded Ultrasonic Guided Waves Using Two-Dimensional Compressed Pulse Analysis.

    Science.gov (United States)

    Malo, Sergio; Fateri, Sina; Livadas, Makis; Mares, Cristinel; Gan, Tat-Hean

    2017-07-01

    Ultrasonic guided waves testing is a technique successfully used in many industrial scenarios worldwide. For many complex applications, the dispersive nature and multimode behavior of the technique still poses a challenge for correct defect detection capabilities. In order to improve the performance of the guided waves, a 2-D compressed pulse analysis is presented in this paper. This novel technique combines the use of pulse compression and dispersion compensation in order to improve the signal-to-noise ratio (SNR) and temporal-spatial resolution of the signals. The ability of the technique to discriminate different wave modes is also highlighted. In addition, an iterative algorithm is developed to identify the wave modes of interest using adaptive peak detection to enable automatic wave mode discrimination. The employed algorithm is developed in order to pave the way for further in situ applications. The performance of Barker-coded and chirp waveforms is studied in a multimodal scenario where longitudinal and flexural wave packets are superposed. The technique is tested in both synthetic and experimental conditions. The enhancements in SNR and temporal resolution are quantified as well as their ability to accurately calculate the propagation distance for different wave modes.

  14. Experimental study of noncontact ultrasonic motor with non-symmetrical electrode

    Institute of Scientific and Technical Information of China (English)

    Yang Bin; Liu Jing-Quan; Chen Di; Zhou Wei-Min; Cai Bing-Chu

    2006-01-01

    We have proposed a novel noncontact ultrasonic motor based on non-symmetrical electrode driving. The configuration of this electrode and the fabrication process of rotors are presented. Its vibration characteristics are computed and analysed by using the finite element method and studied experimentally. Good agreement between them is obtained. Moreover, it is also shown that this noncontact ultrasonic motor is operated in antisymmetric radial vibration mode of B21 mode. The maximum revolution speed for three-blade and six-blade rotors are 5100 and 3700r/min at an input voltage of 20V, respectively. Also, the noncontact high-speed revolution of the rotors can be realized by the parts of Ⅰ, Ⅲ of the electrode or Ⅱ, Ⅳ of the electrode. The levitation distance between the stator and rotor is about 140/μm according to the theoretical calculation and the experimental measurement.

  15. Note: High precision angle generator using multiple ultrasonic motors and a self-calibratable encoder

    Science.gov (United States)

    Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Bong Eom, Tae

    2011-11-01

    We present an angle generator with high resolution and accuracy, which uses multiple ultrasonic motors and a self-calibratable encoder. A cylindrical air bearing guides a rotational motion, and the ultrasonic motors achieve high resolution over the full circle range with a simple configuration. The self-calibratable encoder can compensate the scale error of a divided circle (signal period: 20″) effectively by applying the equal-division-averaged method. The angle generator configures a position feedback control loop using the readout of the encoder. By combining the ac and dc operation mode, the angle generator produced stepwise angular motion with 0.005″ resolution. We also evaluated the performance of the angle generator using a precision angle encoder and an autocollimator. The expanded uncertainty (k = 2) in the angle generation was estimated less than 0.03″, which included the calibrated scale error and the nonlinearity error.

  16. Performance evaluation of dual-frequency driving plate ultrasonic motor based on an analytical model.

    Science.gov (United States)

    Pang, Yafei; Yang, Ming; Chen, Xuying; He, Wei; Li, Shiyang; Li, Chaodong

    2011-08-01

    An analytical model is presented to explain the effects of dual-frequency drive on the plate ultrasonic motor in this paper. The experimental prototype is a plate ultrasonic motor using single-phase asymmetric excitation, which can work under a single vibration or multiple vibration modes. Based on the linear superposition of vibrations with two different excitation frequencies, an analytical model is established using the classic Coulomb friction model, and the non-load rotation speed and maximum stall torque are deduced. Moreover, some crucial parameters such as preload and dead-zone in dual-frequency superposition model are identified or modified automatically by searching for the maximum correlation coefficient between simulation and experimental data using single-frequency drive. It is found that simulation and experiment results agree well when no excitation frequency component is at resonance.

  17. Erasure of memory in paste by irradiation of ultrasonic waves

    Science.gov (United States)

    Nakahara, Akio; Yoneyama, Ryota; Ito, Maruto; Matsuo, Yousuke; Kitsunezaki, So

    2017-06-01

    Densely packed colloidal suspension, called paste, remembers the direction of applied forces, such as vibration and flow, and these memories kept in paste can be visualized as morphology of desiccation crack patterns. For example, when the paste remembers the direction of vibration, all primary cracks propagate in the direction perpendicular to the direction of initial vibration. On the other hand, when the paste remembers the direction of flow, all primary cracks propagate along the direction of initial flow. These results indicate that external forces imprint easy-breakable direction into paste as memories. Therefore, by controlling memories in paste, we can tune to produce various types of crack patterns, such as cellular, radial, lamellar, ring, spiral and lattice structures. Recently we have found that memories in paste can be erased by the irradiation of ultrasonic waves to paste as we obtain only isotropic and cellular crack patterns without any anisotropy related to memory effect. This method can be applied to increase the breaking strength of dried paste by homogenizing microstructure in paste.

  18. 纵弯模式驻波超声波直线电机的研制与实验%Design and Experimental Tests of Longitudinal-flexural Mode Linear Standing Wave Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    郑文灿; 洪尚任; 林华; 鲍时超

    2011-01-01

    以薄板面内振动的纵弯模式直线型超声波电机为目标,对其驱动机理、建模、设计和制作等方面展开研究,设计了全新结构的样机,并对其进行了实验研究与分析.结果表明,电机运行良好,设计达到了预期目标.%This thesis aimed at the realization of the LUM based on Longitudinal-flexural mode, and studiedon its model design, simulation, manufacture and experimentation. The following are the chief research workand achievements of this thesis. The motor is a new type of LUM based on the vibration in plane of the thinplate. Some experiments and research work related to the two sample motors, the experimental results showthat all performed well, and the expected design objective has been successfully obtained.

  19. An efficient approach to optimize the vibration mode of bar-type ultrasonic motors.

    Science.gov (United States)

    Zhu, Hua; Li, Zhirong; Zhao, Chunsheng

    2010-04-01

    The electromechanical coupled dynamic model of the stator of the bar-type ultrasonic motor is derived based on the finite element method. The dynamical behavior of the stator is analyzed via this model and the theoretical result agrees with the experimental result of the stator of the prototype motor very well. Both the structural design principles and the approaches to meet the requirements for the mode of the stator are discussed. Based on the pattern search algorithm, an optimal model to meet the design requirements is established. The numerical simulation results show that this optimal model is effective for the structural design of the stator.

  20. Influence of a high vacuum on the precise positioning using an ultrasonic linear motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Wan-Soo; Lee, Dong-Jin; Lee, Sun-Kyu [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2011-01-15

    This paper presents an investigation of the ultrasonic linear motor stage for use in a high vacuum environment. The slider table is driven by the hybrid bolt-clamped Langevin-type ultrasonic linear motor, which is excited with its different modes of natural frequencies in both lateral and longitudinal directions. In general, the friction behavior in a vacuum environment becomes different from that in an environment of atmospheric pressure and this difference significantly affects the performance of the ultrasonic linear motor. In this paper, to consistently provide stable and high power of output in a high vacuum, frequency matching was conducted. Moreover, to achieve the fine control performance in the vacuum environment, a modified nominal characteristic trajectory following control method was adopted. Finally, the stage was operated under high vacuum condition, and the operating performances were investigated compared with that of a conventional PI compensator. As a result, robustness of positioning was accomplished in a high vacuum condition with nanometer-level accuracy.

  1. Three-degree-of-freedom ultrasonic motor using a 5-mm-diameter piezoelectric ceramic tube.

    Science.gov (United States)

    Mingsen Guo; Junhui Hu; Hua Zhu; Chunsheng Zhao; Shuxiang Dong

    2013-07-01

    A small three-degree-of-freedom ultrasonic motor has been developed using a simple piezoelectric lead zirconate titanate (PZT)-tube stator (OD 5 mm, ID 3 mm, length 15 mm). The stator drives a ball-rotor into rotational motion around one of three orthogonal (x-, y-, and z-) axes by combing the first longitudinal and second bending vibration modes. A motor prototype was fabricated and characterized; its performance was superior to those of previous motors made with a PZT ceramic/metal composite stator of comparable size. The method for further improving the performance was discussed. The motor can be further miniaturized and it has potential to be applied to medical microrobots, endoscopes or micro laparoscopic devices, and cell manipulation devices.

  2. Design of ultrasonic probe and evaluation of ultrasonic waves on E.coli in Sour Cherry Juice

    Directory of Open Access Journals (Sweden)

    B Hosseinzadeh Samani

    2015-09-01

    Full Text Available Introduction: The common method used for juice pasteurization is the thermal method since thermal methods contribute highly to inactivating microbes. However, applying high temperatures would lead to inefficient effects on nutrition and food value. Such effects may include vitamin loss, nutritional flavor loss, non-enzyme browning, and protein reshaping (Kuldiloke, 2002. In order to decrease the adverse effects of the thermal pasteurization method, other methods capable of inactivation of microorganisms can be applied. In doing so, non-thermal methods including pasteurization using high hydrostatic pressure processing (HPP, electrical fields, and ultrasound waves are of interest (Chen and Tseng, 1996. The reason for diminishing microbial count in the presence of ultrasonic waves could be due to the burst of very tiny bubbles developed by ultrasounds which expand quickly and burst in a short time. Due to this burst, special temperature and pressure conditions are developed which could initiate or intensify several physical and/or chemical reactions. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. Materials and methods: In order to supply uniform ultrasonic waves, a 1000 W electric generator (Model MPI, Switzerland working at 20±1 kHz frequency was used. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. For this purpose, a certain amount of sour cherry fruit was purchased from local markets. First, the fruits were washed, cleaned and cored. The prepared fruits were then dewatered using an electric juicer. In order to separate pulp suspensions and tissue components, the extracted juice was poured into a centrifuge with the speed of 6000 rpm for 20 min. For complete separation of the remaining suspended particles, the transparent portion of the extract was passed through a

  3. Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning

    Science.gov (United States)

    Karppinen, Pasi; Salmi, Ari; Moilanen, Petro; Karppinen, Timo; Zhao, Zuomin; Myllylä, Risto; Timonen, Jussi; Hæggström, Edward

    2013-04-01

    Selecting and tuning modes are useful in ultrasonic guided wave non-destructive testing (NDT) since certain modes at various center frequencies are sensitive to specific types of defects. Ideally one should be able to select both the mode and the center frequency of the launched waves. We demonstrated that an affordable laser diode array can selectively launch either the S0 or A0 ultrasonic wave mode at a chosen center frequency into a polymer plate. A fiber-coupled diode array (4 elements) illuminated a 2 mm thick acrylic plate. A predetermined time delay matching the selected mode and frequency was employed between the output of the elements. The generated ultrasound was detected by a 215 kHz piezo receiver. Our results imply that this array permits non-contacting guided wave ultrasonic NDT. The solution is small, affordable, and robust in comparison to conventional pulsed lasers. In addition, it does not require experienced operators.

  4. Guided-wave tomography imaging plate defects by laser-based ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Pil; Lim, Ju Young; Cho, Youn Ho [School of Mechanical Engineering, Pusan National University, Pusan (Korea, Republic of)

    2014-12-15

    Contact-guided-wave tests are impractical for investigating specimens with limited accessibility and rough surfaces or complex geometric features. A non-contact setup with a laser-ultrasonic transmitter and receiver is quite attractive for guided-wave inspection. In the present work, we developed a non-contact guided-wave tomography technique using the laser-ultrasonic technique in a plate. A method for Lamb-wave generation and detection in an aluminum plate with a pulsed laser-ultrasonic transmitter and Michelson-interferometer receiver was developed. The defect shape and area in the images obtained using laser scanning, showed good agreement with the actual defect. The proposed approach can be used as a non-contact online inspection and monitoring technique.

  5. A study on laser-based ultrasonic technique by the use of guided wave tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Junpil, E-mail: jpp@pusan.ac.kr; Lim, Juyoung, E-mail: jpp@pusan.ac.kr [Graduate school, School of Mechanical Engineering, Pusan National University (Korea, Republic of); Cho, Younho [School of Mechanical Engineering, Pusan National University (Korea, Republic of); Krishnaswamy, Sridhar [Center for Quality Engineering and Failure Prevention, Northwestern University, Evanston, IL (United States)

    2015-03-31

    Guided wave tests are impractical for investigating specimens with limited accessibility and coarse surfaces or geometrically complicated features. A non-contact setup with a laser ultrasonic transmitter and receiver is the classic attractive for guided wave inspection. The present work was done to develop a non-contact guided-wave tomography technique by laser ultrasonic technique in a plate-like structure. A method for Lam wave generation and detection in an aluminum plate with a pulse laser ultrasonic transmitter and a Michelson interferometer receiver has been developed. In the images obtained by laser scanning, the defect shape and area showed good agreement with the actual defect. The proposed approach can be used as a non-contact-based online inspection and monitoring technique.

  6. Effects of sonication radiation on oil recovery by ultrasonic waves stimulated water-flooding.

    Science.gov (United States)

    Mohammadian, Erfan; Junin, Radzuan; Rahmani, Omeid; Idris, Ahmad Kamal

    2013-02-01

    Due to partial understanding of mechanisms involved in application of ultrasonic waves as enhanced oil recovery method, series of straight (normal), and ultrasonic stimulated water-flooding experiments were conducted on a long unconsolidated sand pack using ultrasonic transducers. Kerosene, vaseline, and SAE-10 (engine oil) were used as non-wet phase in the system. In addition, a series of fluid flow and temperature rise experiments were conducted using ultrasonic bath in order to enhance the understanding about contributing mechanisms. 3-16% increase in the recovery of water-flooding was observed. Emulsification, viscosity reduction, and cavitation were identified as contributing mechanisms. The findings of this study are expected to increase the insight to involving mechanisms which lead to improving the recovery of oil as a result of application of ultrasound waves.

  7. Dynamic modeling and characteristics analysis of a modal-independent linear ultrasonic motor.

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; Zhou, Shengli; Lv, Qibao; Liu, Zhen

    2016-12-01

    In this paper, an integrated model is developed to analyze the fundamental characteristics of a modal-independent linear ultrasonic motor with double piezoelectric vibrators. The energy method is used to model the dynamics of the two piezoelectric vibrators. The interface forces are coupled into the dynamic equations of the two vibrators and the moving platform, forming a whole machine model of the motor. The behavior of the force transmission of the motor is analyzed via the resulting model to understand the drive mechanism. In particular, the relative contact length is proposed to describe the intermittent contact characteristic between the stator and the mover, and its role in evaluating motor performance is discussed. The relations between the output speed and various inputs to the motor and the start-stop transients of the motor are analyzed by numerical simulations, which are validated by experiments. Furthermore, the dead-zone behavior is predicted and clarified analytically using the proposed model, which is also observed in experiments. These results are useful for designing servo control scheme for the motor.

  8. Effect of acoustic field parameters on arc acoustic binding during ultrasonic wave-assisted arc welding.

    Science.gov (United States)

    Xie, Weifeng; Fan, Chenglei; Yang, Chunli; Lin, Sanbao

    2016-03-01

    As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius.

  9. A New Approach for Quantitative Evaluation of Ultrasonic Wave Attenuation in Composites

    Science.gov (United States)

    Ni, Qing-Qing; Li, Ran; Xia, Hong

    2017-02-01

    When ultrasonic waves propagate in composite materials, the propagation behaviors result from the combination effects of various factors, such as material anisotropy and viscoelastic property, internal microstructure and defects, incident wave characteristics and interface condition between composite components. It is essential to make it clear how these factors affect the ultrasonic wave propagation and attenuation characteristics, and how they mutually interact on each other. In the present paper, based on a newly developed time-domain finite element analysis code, PZflex, a unique approach for clarifying the detailed influence mechanism of aforementioned factors is proposed, in which each attenuation component can be extracted from the overall attenuation and analyzed respectively. By taking into consideration the interrelation between each individual attenuation component, the variation behaviors of each component and internal dynamic stress distribution against material anisotropy and matrix viscosity are separately and quantitatively evaluated. From the detailed analysis results of each attenuation component, the energy dissipation at interface is a major component in ultrasonic wave attenuation characteristics, which can provide a maximum contribution rate of 68.2 % to the overall attenuation, and each attenuation component is closely related to the material anisotropy and viscoelasticity. The results clarify the correlation between ultrasonic wave propagation characteristics and material viscoelastic properties, which will be useful in the further development of ultrasonic technology in defect detection.

  10. PARAFAC Decomposition for Ultrasonic Wave Sensing of Fiber Bragg Grating Sensors: Procedure and Evaluation

    Directory of Open Access Journals (Sweden)

    Rencheng Zheng

    2015-07-01

    Full Text Available Ultrasonic wave-sensing technology has been applied for the health monitoring of composite structures, using normal fiber Bragg grating (FBG sensors with a high-speed wavelength interrogation system of arrayed waveguide grating (AWG filters; however, researchers are required to average thousands of repeated measurements to distinguish significant signals. To resolve this bottleneck problem, this study established a signal-processing strategy that improves the signal-to-noise ratio for the one-time measured signal of ultrasonic waves, by application of parallel factor analysis (PARAFAC technology that produces unique multiway decomposition without additional orthogonal or independent constraints. Through bandpass processing of the AWG filter and complex wavelet transforms, ultrasonic wave signals are preprocessed as time, phase, and frequency profiles, and then decomposed into a series of conceptual three-way atoms by PARAFAC. While an ultrasonic wave results in a Bragg wavelength shift, antiphase fluctuations can be observed at two adjacent AWG ports. Thereby, concentrating on antiphase features among the three-way atoms, a fitting atom can be chosen and then restored to three-way profiles as a final result. An experimental study has revealed that the final result is consistent with the conventional 1024-data averaging signal, and relative error evaluation has indicated that the signal-to-noise ratio of ultrasonic waves can be significantly improved.

  11. Analysis of partial discharge Ultrasonic wave characteristic on typical Defects in GIS

    Directory of Open Access Journals (Sweden)

    Yang Jing Gang

    2016-01-01

    Full Text Available For analyzing partial discharge ultrasonic wave characteristic on typical defects in SF6 gas insulation switchgear (GIS, a 110 kV GIS was taken as an object to design and simulate the typical partial discharge models in GIS. There are point electrode model on bus and cavity of GIS, floating electrode model, air interstice model in insulator, metal particle and iron core electromagnetic shock models. PD signals on different defects were thus detected with the ultrasonic method. The experimental results indicated that the ultrasonic signals of different defects showed different characteristics in waveform, amplitude and phase resolved partial discharge chart, which is helpful in PD pattern recognition for GIS.

  12. Study of a stator of a piezoelectric rotary ultrasonic motor

    OpenAIRE

    Rebollo Sancho, Gonzalo

    2015-01-01

    En este estudio es presentado un modelo matemático y los resultados de simulación numérica que son parte del estudio acerca de la dinámica del estator de un motor ultrasónico de onda viajera. El estator está dividido principalmente en tres partes; Un anillo de material piezoeléctrico, un adhesivo y un anillo metálico que transmite las ondas vibratorias al rotor. El momento giratorio es producido por la excitación del estator con una onda de flexión transmitida al rotor a través de la fricción...

  13. Development of an ultrasonic linear motor with ultra-positioning capability and four driving feet.

    Science.gov (United States)

    Zhu, Cong; Chu, Xiangcheng; Yuan, Songmei; Zhong, Zuojin; Zhao, Yanqiang; Gao, Shuning

    2016-12-01

    This paper presents a novel linear piezoelectric motor which is suitable for rapid ultra-precision positioning. The finite element analysis (FEA) was applied for optimal design and further analysis, then experiments were conducted to investigate its performance. By changing the input signal, the proposed motor was found capable of working in the fast driving mode as well as in the precision positioning mode. When working in the fast driving mode, the motor acts as an ultrasonic motor with maximum no-load speed up to 181.2mm/s and maximum thrust of 1.7N at 200Vp-p. Also, when working in precision positioning mode, the motor can be regarded as a flexible hinge piezoelectric actuator with arbitrary motion in the range of 8μm. The measurable minimum output displacement was found to be 0.08μm, but theoretically, can be even smaller. More importantly, the motor can be quickly and accurately positioned in a large stroke.

  14. Degradation of methyl orange through synergistic effect of zirconia nanotubes and ultrasonic wave.

    Science.gov (United States)

    Zhao, Jianling; Wang, Xixin; Zhang, Libin; Hou, Xiaorui; Li, Ying; Tang, Chengchun

    2011-04-15

    Zirconia nanotubes with a length of 25 μm, inner diameter of 80 nm, and wall thickness of 35 nm were prepared by anodization method in mixture of formamide and glycerol (volume ratio = 1:1) containing 1 wt% NH(4)F and 1 wt% H(2)O. Experiments showed that zirconia nanotubes and ultrasonic wave had synergistic degradation effect for methyl orange and the efficiency of ultrasonic wave increased by more than 7 times. The decolorization percentage was influenced by pH value of the solution. Methyl orange was easy to be degraded in acidic solution. The decolorization percentage of methyl orange reached 97.6% when degraded for 8h in 20mg/L methyl orange solution with optimal pH value 2. The reason of synergistic degradation effect for methyl orange might be that adsorption of methyl orange onto zirconia nanotubes resulted in the easy degradation of the methyl orange through ultrasonic wave.

  15. Simulations of Propagation and Radiation of A0-mode Lamb Wave in Ultrasonic Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jin Ho; Joo, Young Sang; Kim, Jong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Rhee, Hui Nam [Sunchon National University, Sunchon (Korea, Republic of)

    2010-10-15

    As the sodium coolant of a sodium-cooled fast reactor (SFR) is opaque to light, a conventional visual inspection cannot be used for carrying out an in-service inspection of the internal structures under a sodium level. An ultrasonic wave should be applied for an under-sodium viewing of the internal structures in a reactor vessel. Recently, a new plate type ultrasonic waveguide sensor has been developed for the versatile applications in the under-sodium viewing application. In the plate type ultrasonic waveguide sensor, the A0 mode Lamb wave is utilized for the long distance propagation and the effective radiation capability in a fluid. And a radiation beam steering technique is presented which is capable of steering an ultrasonic radiation beam of a waveguide sensor without a mechanical movement of the sensor module. In this paper, the numerical simulation of the propagation and radiation of A0-mode Lamb wave in ultrasonic leaky wave generation from waveguide sensor is performed by using the finite element method (FEM). The objective of this research is to compare the previous theoretical and experimental results with its numerical simulation

  16. Acoustic emisson and ultrasonic wave characteristics in TIG-welded 316 stainless steel

    Science.gov (United States)

    Lee, Jin Kyung; Lee, Joon Hyun; Lee, Sang Pill; Son, In Su; Bae, Dong Su

    2014-05-01

    A TIG welded 316 stainless steel materials will have a large impact on the design and the maintenance of invessel components including pipes used in a nuclear power plant, and it is important to clear the dynamic behavior in the weld part of stainless steel. Therefore, nondestructive techniques of acoustic emission (AE) and ultrasonic wave were applied to investigate the damage behavior of welded stainless steel. The velocity and attenuation ratio of the ultrasonic wave at each zone were measured, and a 10 MHz sensor was used. We investigated the relationship between dynamic behavior and AE parameters analysis and derived the optimum parameters to evaluate the damage degree of the specimen. By measuring the velocity and the attenuation of an ultrasonic wave propagating each zone of the welded stainless steel, the relation of the ultrasonic wave and metal structure at the base metal, heat affected zone (HAZ) metal and weld metal is also discussed. The generating tendency of cumulated counts is similar to that of the load curve. The attenuation ratios from the ultrasonic test results were 0.2 dB/mm at the base zone, and 0.52 dB/mm and 0.61 dB/mm at the HAZ zone and weld zone, respectively.

  17. Effects of Ultrasonic Waves on Vapor-Liquid Equilibrium of Cyclohexane/Benzene

    Directory of Open Access Journals (Sweden)

    Siti Kholijah Abdul Mudalip

    2011-01-01

    Full Text Available Separation of azeotropic mixtures is one of the most challenging separation processes in chemical industry. Special separation techniques such as azeotropic and extractive distillation are required to separate these mixtures. In this work, an innovative technique which incorporates ultrasonic waves during separation of Cyclohexane (Chx/ Benzene (Bz via distillation process was explored. The effects of ultrasonic wave at different intensities at 50, 100, 200 and 250 W/A.cm2 and at a fixed frequency of 40 kHz on vapor-liquid equilibrium (VLE of Chx/ Bz were investigated. Studies were also done to examine the effects of ultrasonic frequencies on the VLE data at 25 and 68 kHz. It was found that ultrasonic waves at 100 W/A.cm2 intensity and 25 kHz frequency gave the highest relative volatility, α at 2.505 and completely eliminated the azeotropic point. The results revealed that ultrasonic waves had potential to favourably manipulate α, and hence, the VLE of Chx/ Bz.

  18. Comparison of ultrasonic wave speed measurements on wax at elevated temperatures to numerical method predictions

    Science.gov (United States)

    Moore, David G.; Stair, Sarah L.; Jack, David A.

    2017-02-01

    Ultrasonic stress wave amplitude and time-of-flight values may change as a media is heated. The measurement of relatively small variations in velocity and material attenuation can detect and quantify significant variations within a material's microstructure, such as a change in phase from solid to liquid. This paper discusses the experimental setup, ultrasonic wave speed tracking methods and signal analysis algorithms that are used in this study to document the changes within highly attenuative wax material as it is either being heated or cooled from 25°C to 90°C. The experimental set-up utilizes ultrasonic probes in a through-transmission configuration. The ultrasonic waveforms are recorded and analyzed during long duration thermal experiments. To complement the ultrasonic data, a Discontinuous-Galerkin Model (DGM) was also created, which uses unstructured meshes to determine how waves travel in this media and how the sound interacts with the prescribed boundary conditions. This numerical method solves particle motion travel using partial differential equations and outputs a wave trace per unit time. Both experimental and analytical data are presented and compared. The experimental and analytical data share some similarities; however, the differences between the two, including a high frequency component present in the analytical data that is not observed in the experimental data, are continuing to be studied and addressed in the model.

  19. The comparison of removing plug by ultrasonic wave, chemical deplugging agent and ultrasound-chemical combination deplugging for near-well ultrasonic processing technology.

    Science.gov (United States)

    Wang, Zhenjun; Xu, Yuanming; Bajracharya, Suman

    2015-11-01

    Near-well ultrasonic processing technology is characterized by high adaptability, simple operation, low cost and zero pollution. The main plugs of oil production include paraffin deposition plug, polymer plug, and drilling fluid plug etc. Although some good results have been obtained through laboratory experiments and field tests, systematic and intensive studies are absent for certain major aspects, such as: effects of ultrasonic treatment for different kinds of plugs and whether effect of ultrasound-chemicals combination deplugging is better than that of ultrasonic deplugging. In this paper, the experiments of removing drilling fluid plug, paraffin deposition plug and polymer plug by ultrasonic wave, chemical deplugging agent and ultrasound-chemical combination deplugging respectively are carried out. Results show that the effect of ultrasound-chemical combination deplugging is clearly better than that of using ultrasonic wave and chemical deplugging agent separately, which indicates that ultrasonic deplugging and chemical deplugging can produce synergetic effects. On the one hand, ultrasonic treatment can boost the activity of chemical deplugging agent and turn chemical deplugging into dynamic chemical process, promoting chemical agent reaction speed and enhancing deplugging effect; on the other hand, chemical agent can reduce the adhesion strength of plugs so that ultrasonic deplugging effect can be improved significantly. Experimental results provide important reference for near-well ultrasonic processing technology.

  20. High-frequency guided ultrasonic waves to monitor corrosion thickness loss

    Science.gov (United States)

    Fromme, Paul; Bernhard, Fabian; Masserey, Bernard

    2017-02-01

    Corrosion due to adverse environmental conditions can occur for a range of industrial structures, e.g., ships and offshore oil platforms. Pitting corrosion and generalized corrosion can lead to the reduction of the strength and thus degradation of the structural integrity. The nondestructive detection and monitoring of corrosion damage in difficult to access areas can be achieved using high frequency guided ultrasonic waves propagating along the structure. Using standard ultrasonic transducers with single sided access to the structure, the two fundamental Lamb wave modes were selectively generated simultaneously, penetrating through the complete thickness of the structure. The wave propagation and interference of the guided wave modes depends on the thickness of the structure. Numerical simulations were performed using a 2D Finite Difference Method (FDM) algorithm in order to visualize the guided wave propagation and energy transfer across the plate thickness. Laboratory experiments were conducted and the wall thickness reduced initially uniformly by milling of the steel structure. Further measurements were conducted using accelerated corrosion in salt water. From the measured signal change due to the wave mode interference, the wall thickness reduction was monitored and good agreement with theoretical predictions was achieved. Corrosion can lead to non-uniform thickness reduction and the influence of this on the propagation of the high frequency guided ultrasonic waves was investigated. The wave propagation in a steel specimen with varying thickness was measured experimentally and the influence on the wave propagation characteristics quantified.

  1. Numerical simulation of ultrasonic wave transmission experiments in rocks of shale gas reservoirs

    Science.gov (United States)

    Chen, Qiao; Yao, Guanghua; Zhu, Honglin; Tan, Yanhu; Xu, Fenglin

    2017-01-01

    Shale gas reservoirs have risen in importance in China's new power source exploration and development program. The investigation of the propagation of ultrasonic waves in shale forms the basis for the full waveform application of acoustic logging data to the exploration of shale gas. Using acoustic wave theory, initial conditions, vibration source conditions, and stability conditions are developed in combination with experimental background of ultrasonic wave transmission. With improved boundary conditions, we performed numerical simulations of the ultrasound transmission experiments in shale using the high-order staggered-grid finite difference method (second-order in the time domain and fourth-order in the space domain). With programs developed within MatLab, the results obtained from numerical simulations agree well with experimental results based on physical models. In addition, using snapshots of the wave field that give a microscopic perspective, the propagation laws for ultrasonic waves can be analyzed. Using this method, human error is avoided, transmission experiments costs can be reduced and efficiency improved. This method extends the scope of experimental investigations regarding the transmission of ultrasonic waves in a shale gas reservoir with increasing stratification, and thus has great theoretical value and practical significance.

  2. Numerical simulation of ultrasonic wave transmission experiments in rocks of shale gas reservoirs

    Directory of Open Access Journals (Sweden)

    Qiao Chen

    2017-01-01

    Full Text Available Shale gas reservoirs have risen in importance in China’s new power source exploration and development program. The investigation of the propagation of ultrasonic waves in shale forms the basis for the full waveform application of acoustic logging data to the exploration of shale gas. Using acoustic wave theory, initial conditions, vibration source conditions, and stability conditions are developed in combination with experimental background of ultrasonic wave transmission. With improved boundary conditions, we performed numerical simulations of the ultrasound transmission experiments in shale using the high-order staggered-grid finite difference method (second-order in the time domain and fourth-order in the space domain. With programs developed within MatLab, the results obtained from numerical simulations agree well with experimental results based on physical models. In addition, using snapshots of the wave field that give a microscopic perspective, the propagation laws for ultrasonic waves can be analyzed. Using this method, human error is avoided, transmission experiments costs can be reduced and efficiency improved. This method extends the scope of experimental investigations regarding the transmission of ultrasonic waves in a shale gas reservoir with increasing stratification, and thus has great theoretical value and practical significance.

  3. Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces.

    Science.gov (United States)

    Colombi, Andrea; Ageeva, Victoria; Smith, Richard J; Clare, Adam; Patel, Rikesh; Clark, Matt; Colquitt, Daniel; Roux, Philippe; Guenneau, Sebastien; Craster, Richard V

    2017-07-28

    Recent years have heralded the introduction of metasurfaces that advantageously combine the vision of sub-wavelength wave manipulation, with the design, fabrication and size advantages associated with surface excitation. An important topic within metasurfaces is the tailored rainbow trapping and selective spatial frequency separation of electromagnetic and acoustic waves using graded metasurfaces. This frequency dependent trapping and spatial frequency segregation has implications for energy concentrators and associated energy harvesting, sensing and wave filtering techniques. Different demonstrations of acoustic and electromagnetic rainbow devices have been performed, however not for deep elastic substrates that support both shear and compressional waves, together with surface Rayleigh waves; these allow not only for Rayleigh wave rainbow effects to exist but also for mode conversion from surface into shear waves. Here we demonstrate experimentally not only elastic Rayleigh wave rainbow trapping, by taking advantage of a stop-band for surface waves, but also selective mode conversion of surface Rayleigh waves to shear waves. These experiments performed at ultrasonic frequencies, in the range of 400-600 kHz, are complemented by time domain numerical simulations. The metasurfaces we design are not limited to guided ultrasonic waves and are a general phenomenon in elastic waves that can be translated across scales.

  4. Modeling and Control Of Surface Acoustic Wave Motors

    NARCIS (Netherlands)

    Feenstra, P.J.

    2005-01-01

    This thesis introduces Rayleigh waves and describes the generation of Rayleigh waves. Furthermore, the principle of operation of a SAW motor is analyzed. The analysis is based on a contact model, which describes the behavior between slider and stator. Due to the contact model, the microscopic and

  5. Monitoring ageing of alkali resistant glass fiber reinforced cement (GRC) using guided ultrasonic waves

    Science.gov (United States)

    Eiras, J. N.; Amjad, U.; Mahmoudabadi, E.; Payá, J.; Bonilla, M.; Kundu, T.

    2013-04-01

    Glass fiber reinforced cement (GRC) is a Portland cement based composite with alkali resistant (AR) glass fibers. The main drawback of this material is the ageing of the reinforcing fibers with time and especially in presence of humidity in the environment. Until now only destructive methods have been used to evaluate the durability of GRC. In this study ultrasonic guided wave inspection of plate shaped specimens has been carried out. The results obtained here show that acoustic signatures are capable of discerning ageing in GRC. Therefore, the ultrasonic guided wave based inspection technique is a promising method for the nondestructive evaluation of the durability of the GRC.

  6. Enhancing gas-phase reaction in a plasma using high intensity and high power ultrasonic acoustic waves

    DEFF Research Database (Denmark)

    2010-01-01

    is absorbed into said plasma (104), and where a sound pressure level of said generated ultrasonic high intensity and high power acoustic waves (102) is at least substantially 140 dB and where an acoustic power of said generated ultrasonic high intensity and high power acoustic waves (102); is at least......This invention relates to enhancing a gas-phase reaction in a plasma comprising: creating plasma (104) by at least one plasma source (106), and wherein that the method further comprises: generating ultrasonic high intensity and high power acoustic waves (102) having a predetermined amount...... of acoustic energy by at least one ultrasonic high intensity and high power gas-jet acoustic wave generator (101), where said ultrasonic high intensity and high power acoustic waves are directed to propagate towards said plasma (104) so that at least a part of said predetermined amount of acoustic energy...

  7. Three dimensional image-based simulation of ultrasonic wave propagation in polycrystalline metal using phase-field modeling.

    Science.gov (United States)

    Nakahata, K; Sugahara, H; Barth, M; Köhler, B; Schubert, F

    2016-04-01

    When modeling ultrasonic wave propagation in metals, it is important to introduce mesoscopic crystalline structures because the anisotropy of the crystal structure and the heterogeneity of grains disturb ultrasonic waves. In this paper, a three-dimensional (3D) polycrystalline structure generated by multiphase-field modeling was introduced to ultrasonic simulation for nondestructive testing. 3D finite-element simulations of ultrasonic waves were validated and compared with visualization results obtained from laser Doppler vibrometer measurements. The simulation results and measurements showed good agreement with respect to the velocity and front shape of the pressure wave, as well as multiple scattering due to grains. This paper discussed the applicability of a transversely isotropic approach to ultrasonic wave propagation in a polycrystalline metal with columnar structures.

  8. Precise Speed Tracking Control of Ultrasonic Motors via Sampled-Data H∞ Control

    Science.gov (United States)

    Vongsaroj, Tharathip; Kobayashi, Yasuhide; Fujioka, Hisaya; Yanabe, Shigeo

    In this paper, we consider a synthesis problem of digital controllers for speed tracking control systems of ultrasonic motors. In previous works, a continuous-time H∞ control based synthesis involving the Tustin transformation has been utilized to solve the problem, where it has been empirically known that an over-estimation of a modeling error is needed to avoid speed fluctuations in a high frequency range. In this paper, it is shown that a desirable performance can be obtained by the sampled-data H∞ control synthesis without such conservativeness in the modeling.

  9. Inverse problems in cancellous bone: estimation of the ultrasonic properties of fast and slow waves using Bayesian probability theory.

    Science.gov (United States)

    Anderson, Christian C; Bauer, Adam Q; Holland, Mark R; Pakula, Michal; Laugier, Pascal; Bretthorst, G Larry; Miller, James G

    2010-11-01

    Quantitative ultrasonic characterization of cancellous bone can be complicated by artifacts introduced by analyzing acquired data consisting of two propagating waves (a fast wave and a slow wave) as if only one wave were present. Recovering the ultrasonic properties of overlapping fast and slow waves could therefore lead to enhancement of bone quality assessment. The current study uses Bayesian probability theory to estimate phase velocity and normalized broadband ultrasonic attenuation (nBUA) parameters in a model of fast and slow wave propagation. Calculations are carried out using Markov chain Monte Carlo with simulated annealing to approximate the marginal posterior probability densities for parameters in the model. The technique is applied to simulated data, to data acquired on two phantoms capable of generating two waves in acquired signals, and to data acquired on a human femur condyle specimen. The models are in good agreement with both the simulated and experimental data, and the values of the estimated ultrasonic parameters fall within expected ranges.

  10. Three phase full wave dc motor decoder

    Science.gov (United States)

    Studer, P. A. (Inventor)

    1977-01-01

    A three phase decoder for dc motors is disclosed which employs an extremely simple six transistor circuit to derive six properly phased output signals for fullwave operation of dc motors. Six decoding transistors are coupled at their base-emitter junctions across a resistor network arranged in a delta configuration. Each point of the delta configuration is coupled to one of three position sensors which sense the rotational position of the motor. A second embodiment of the invention is disclosed in which photo-optical isolators are used in place of the decoding transistors.

  11. Analysis on the anisotropic electromechanical properties of lead magnoniobate titanate single crystal for ring type ultrasonic motors

    Directory of Open Access Journals (Sweden)

    Xiang Shi

    2016-11-01

    Full Text Available This work discussed the optimized cut of single crystal lead magnoniobate titanate (PMNT for use of ring type travelling wave ultrasonic motors (USMs, according to anisotropic analysis on electromechanical properties. The selection criterion of crystal orientation relies on the circular uniformity of the induced travelling wave amplitude on the stator surface. By calculating the equivalent elastic coefficient c11 and lateral piezoelectric constant d31, the optimal crystal orientations were proposed for PMNT single crystals poled along different directions. For single crystal poled along c directions, the optimal orientation lies along [001]c with d31=-1335pC/N and k31=0.87. The crystallographic orientation [025]c is the optimized orientation for single crystals poled along c direction with d31=199pC/N and k31=0.55. The optimal orientation of 1R configuration is [332¯]c with a large enhancement of d31 = 1201 and k31=0.92.

  12. Analysis on the anisotropic electromechanical properties of lead magnoniobate titanate single crystal for ring type ultrasonic motors

    Science.gov (United States)

    Shi, Xiang; Huang, Wenbin; Li, Fei; Li, Zhenrong; Xu, Zhuo; Jiang, Xiaoning; Wei, Xiaoyong

    2016-11-01

    This work discussed the optimized cut of single crystal lead magnoniobate titanate (PMNT) for use of ring type travelling wave ultrasonic motors (USMs), according to anisotropic analysis on electromechanical properties. The selection criterion of crystal orientation relies on the circular uniformity of the induced travelling wave amplitude on the stator surface. By calculating the equivalent elastic coefficient c11 and lateral piezoelectric constant d31, the optimal crystal orientations were proposed for PMNT single crystals poled along different directions. For single crystal poled along c directions, the optimal orientation lies along [001]c with d31=-1335pC/N and k31=0.87. The crystallographic orientation [025]c is the optimized orientation for single crystals poled along c direction with d31=199pC/N and k31=0.55. The optimal orientation of 1R configuration is [332 ¯ ] c with a large enhancement of d31 = 1201 and k31=0.92.

  13. Ultrasonic waves induce rapid zeolite synthesis in a seawater solution.

    Science.gov (United States)

    Belviso, Claudia; Cavalcante, Francesco; Fiore, Saverio

    2013-01-01

    The synthesis of zeolites from fly ash was performed through a low-temperature hydrothermal process with seawater. Compared with the results obtained using the same hydrothermal method but in the absence of sonication, the application of an ultrasonic pre-treatment to the conventional hydrothermal process with seawater reduces the crystallization temperature below that observed when hydrothermal synthesis is performed using distilled water.

  14. Intelligent Control Algorithm of PTZ System Driven by Two-DOF Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    Wu Songsen; Leng Xuefei; Jin Jiamei; Wang Bihui; Mao Xingyun

    2015-01-01

    It is difficult for the traditional pan-tilt-zoom (PTZ) system driven by electromagnetic motor to meet the growing demand for video surveillance system .The key challenge is high positioning accuracy ,high dynamic per-formance and miniaturization of the PTZ system .Here a PTZ system driven by two degree-of-freedom obelisk-shaped ultrasonic motor with single stator is presented ,and its intelligent control algorithm is studied .The struc-ture and driving mechanism of the presented PTZ system are analyzed by both simulation and experiment .To solve the complex nonlinear factors ,e .g .time-variation ,dead zone ,the fuzzy PID control algorithm and the variable gain cross-coupled control strategy are combined to improve the control performance .The results show that the proposed algorithm has faster response ,higher precision than traditional control algorithm ,and it also has a good robustness to prevent the effect of interference .

  15. Sensitivity Distribution Properties of a Phase-Shifted Fiber Bragg Grating Sensor to Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Qi Wu

    2014-01-01

    Full Text Available In this research, the sensitivity distribution properties of a phase-shifted fiber Bragg grating (PS-FBG to ultrasonic waves were investigated employing the surface attachment method. A careful consideration was taken and examined by experimental results to explain that the distances and angles between the sensor and ultrasonic source influence not only the amplitudes, but also the initial phases, waveforms, and spectra of detected signals. Furthermore, factors, including the attachment method and the material’s geometric dimensions, were also discussed. Although these results were obtained based on PS-FBG, they are also applicable to a normal FBG sensor or even an optical fiber sensor, due to the identical physical changes induced by ultrasonic waves in all three. Thus, these results are useful for applications of optical fiber sensors in non-destructive testing and structural health monitoring.

  16. Sensitivity distribution properties of a phase-shifted fiber bragg grating sensor to ultrasonic waves.

    Science.gov (United States)

    Wu, Qi; Okabe, Yoji; Saito, Kazuya; Yu, Fengming

    2014-01-09

    In this research, the sensitivity distribution properties of a phase-shifted fiber Bragg grating (PS-FBG) to ultrasonic waves were investigated employing the surface attachment method. A careful consideration was taken and examined by experimental results to explain that the distances and angles between the sensor and ultrasonic source influence not only the amplitudes, but also the initial phases, waveforms, and spectra of detected signals. Furthermore, factors, including the attachment method and the material's geometric dimensions, were also discussed. Although these results were obtained based on PS-FBG, they are also applicable to a normal FBG sensor or even an optical fiber sensor, due to the identical physical changes induced by ultrasonic waves in all three. Thus, these results are useful for applications of optical fiber sensors in non-destructive testing and structural health monitoring.

  17. Angular dependence of the ultrasonic SH wave velocity in rolled metal sheets

    Science.gov (United States)

    Sayers, C. M.; Proudfoot, G. G.

    THE ULTRASONIC SH wave technique is a promising method for separating out the effects of texture and stress on the ultrasonic velocity, and allows the texture and stress to be determined separately. ALEN and LANGMAN (1985) have reported measurements of the angular dependence of the SH wave velocity in several unstressed rolled metal sheets of aluminium, stainless steel, copper and brass. In this paper neutron diffraction measurements of the texture of several of these sheets are presented, and parameters entering into an expansion of the crystallite orientation distribution function are determined. These are in good agreement with the values obtained by fitting the ultrasonic results to theory. The validity of the first order expression for the effect of texture is assessed, and the contribution due to beam skewing is calculated.

  18. An ultrasonic guided wave approach for the inspection of overhead transmission line cables

    DEFF Research Database (Denmark)

    Kappatos, Vasileios; Yücel, Mehmet K.; Legg, Mathew

    2017-01-01

    Inspection of overhead transmission line cables is performed using various non-destructive testing techniques, such as visual, temperature, and eddy current-based inspection; yet each of these techniques have their respective shortcomings and safety concerns. The use of ultrasonic guided waves...... as a non-destructive testing technique is well established for simple geometries such as plates, pipes, and rods. However, its application for multi-wire cables is still in development. In this study, ultrasonic guided waves excited by a shear mode transducer collar are utilised as a defect detection...... technique for untensioned aluminium conductor steel reinforced cable specimens. The identification and analysis of wave propagation for a broad range of frequencies is performed using a laser scanning vibrometer, and the effect of defect size on wave propagation is studied. Signal processing algorithms...

  19. Antisymmetric-Symmetric Mode Conversion of Ultrasonic Lamb Waves and Negative Refraction on Thin Steel Plate

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young H. [Dept. of Physics and Earth Science, Korea Science Academy of KAIST, Busan (Korea, Republic of); Sung, Jin Woo [Dept. of Physics and Astronomy, Seoul National University, Seoul, (Korea, Republic of)

    2013-06-15

    In this study, focusing of ultrasonic Lamb wave by negative refraction with mode conversion from antisymmetric to symmetric mode was investigated. When a wave propagates backward by negative refraction, the energy flux is antiparallel to the phase velocity. Backward propagation of Lamb wave is quite well known, but the behavior of backward Lamb wave at an interface has rarely been investigated. A pin-type transducer is used to detect Lamb wave propagating on a steel plate with a step change in thickness. Conversion from forward to backward propagating mode leads to negative refraction and thus wave focusing. By comparing the amplitudes of received Lamb waves at a specific frequency measured at different distance between transmitter and interface, the focusing of Lamb wave due to negative refraction was confirmed.

  20. Schlieren visualization of ultrasonic standing waves in mm-sized chambers for ultrasonic particle manipulation.

    Science.gov (United States)

    Möller, Dirk; Degen, Nicolas; Dual, Jurg

    2013-06-28

    For the design and characterization of ultrasonic particle manipulation devices the pressure field in the fluid cavity is of great interest. The schlieren method provides an optical tool for the visualization of such pressure fields. Due to its purely optical nature this experimental method has got some unique advantages compared to methods like particle tracking. A vertical schlieren setup and an investigation with the same of a mm-sized chamber used to agglomerate particles are presented here. The schlieren images show a two-dimensional representation of the whole pressure distribution recorded simultaneously with a good resolution in time. The gained description of the pressure field is shown to be in agreement with a numerical simulation. Thermal effects as well as streaming effects are shown. The results show the great potential of schlieren visualization to investigate ultrasonic particle manipulation devices. Visualized are pressure fields, acoustic streaming, temperature effects and effects caused by fluid volumes of different density.

  1. Effect of Filler Composition on the Brazing of Alumina to Copper Using Ultrasonic Wave

    Institute of Scientific and Technical Information of China (English)

    Khalid M. HAFEZ; Masaaki NAKA

    2003-01-01

    An ultrasonic wave was applied during brazing of alumina to Cu. First alumina was metallized by applying ultrasonicwave in braze bath. Then the metallized alumina was brazed with Cu using the same filler alloy. The filler used wereZn-Al alloys and Zn-Sn A

  2. Schlieren visualization of ultrasonic standing waves in mm-sized chambers for ultrasonic particle manipulation

    OpenAIRE

    Möller, Dirk; Degen, Nicolas; Dual, Jurg

    2013-01-01

    Background For the design and characterization of ultrasonic particle manipulation devices the pressure field in the fluid cavity is of great interest. The schlieren method provides an optical tool for the visualization of such pressure fields. Due to its purely optical nature this experimental method has got some unique advantages compared to methods like particle tracking. Results A vertical schlieren setup and an investigation with the same of a mm-sized chamber used to agglomerate particl...

  3. On the development and testing of a guided ultrasonic wave array for structural integrity monitoring

    OpenAIRE

    Fromme, P.; Wilcox, P. D.; Lowe, M. J. S.; Canvley, P.

    2006-01-01

    The prototype of a guided ultrasonic wave array for the structural integrity monitoring of large, plate-like structures has been designed, built, and tested. The development of suitably small transducers for the excitation and measurement of the first antisymmetric Lamb wave mode A(0) is described. The array design consists of a ring of 32 transducers, permanently bonded to the structure with a protective membrane, in a compact housing with the necessary multiplexing electronics. Using a phas...

  4. Numerical Simulation of Monitoring Corrosion in Reinforced Concrete Based on Ultrasonic Guided Waves

    OpenAIRE

    Zheng, Zhupeng; Lei, Ying; Xue, Xin

    2014-01-01

    Numerical simulation based on finite element method is conducted to predict the location of pitting corrosion in reinforced concrete. Simulation results show that it is feasible to predict corrosion monitoring based on ultrasonic guided wave in reinforced concrete, and wavelet analysis can be used for the extremely weak signal of guided waves due to energy leaking into concrete. The characteristic of time-frequency localization of wavelet transform is adopted in the corrosion monitoring of re...

  5. A cylindrical rod ultrasonic motor with 1 mm diameter and its application in endoscopic OCT

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tieying; ZHANG Kai; CHEN Yu; WANG Huan; WU Jigang; JIANG Kaili; XUE Ping

    2005-01-01

    A tiny ultrasonic motor was constructed by using a piezoelectric ceramic cylindrical rod as a vibration generator of the stator. The fabricated tiny motor has a diameter of 1 mm, a length of 5 mm and a weight of 36 mg. The resonant frequency is 32 kHz with one fixed boundary or 83 kHz with two free boundaries. Four silver electrodes were deposited on the cylindrical surface. The spacing between two adjacent electrodes was carefully designed. A method was developed for the polarization of the stator. By using the bending vibration mode of the stator, the motor shows a performance with a speed of 1800 rpm and a stalled torque of 4 -Nm, and can bear a high driving voltage up to 350 Vpp. The motor was used to drive an optical prism for circular scanning in an endoscopic OCT system. The tomographic images of the inner cavities of a plastic tube and a scallion were obtained, and the resolution was of the order of micrometer-scale.

  6. Digital core based transmitted ultrasonic wave simulation and velocity accuracy analysis

    Science.gov (United States)

    Zhu, Wei; Shan, Rui

    2016-06-01

    Transmitted ultrasonic wave simulation (TUWS) in a digital core is one of the important elements of digital rock physics and is used to study wave propagation in porous cores and calculate equivalent velocity. When simulating wave propagates in a 3D digital core, two additional layers are attached to its two surfaces vertical to the wave-direction and one planar wave source and two receiver-arrays are properly installed. After source excitation, the two receivers then record incident and transmitted waves of the digital rock. Wave propagating velocity, which is the velocity of the digital core, is computed by the picked peak-time difference between the two recorded waves. To evaluate the accuracy of TUWS, a digital core is fully saturated with gas, oil, and water to calculate the corresponding velocities. The velocities increase with decreasing wave frequencies in the simulation frequency band, and this is considered to be the result of scattering. When the pore fluids are varied from gas to oil and finally to water, the velocity-variation characteristics between the different frequencies are similar, thereby approximately following the variation law of velocities obtained from linear elastic statics simulation (LESS), although their absolute values are different. However, LESS has been widely used. The results of this paper show that the transmission ultrasonic simulation has high relative precision.

  7. A contactless ultrasonic surface wave approach to characterize distributed cracking damage in concrete.

    Science.gov (United States)

    Ham, Suyun; Song, Homin; Oelze, Michael L; Popovics, John S

    2017-03-01

    We describe an approach that utilizes ultrasonic surface wave backscatter measurements to characterize the volume content of relatively small distributed defects (microcrack networks) in concrete. A simplified weak scattering model is used to demonstrate that the scattered wave field projected in the direction of the surface wave propagation is relatively insensitive to scatterers that are smaller than the propagating wavelength, while the scattered field projected in the opposite direction is more sensitive to sub-wavelength scatterers. Distributed microcracks in the concrete serve as the small scatterers that interact with a propagating surface wave. Data from a finite element simulation were used to demonstrate the viability of the proposed approach, and also to optimize a testing configuration to collect data. Simulations were validated through experimental measurements of ultrasonic backscattered surface waves from test samples of concrete constructed with different concentrations of fiber filler (0.0, 0.3 and 0.6%) to mimic increasing microcrack volume density and then samples with actual cracking induced by controlled thermal cycles. A surface wave was induced in the concrete samples by a 50kHz ultrasonic source operating 10mm above the surface at an angle of incidence of 9°. Silicon-based miniature MEMS acoustic sensors located a few millimeters above the concrete surface both behind and in front of the sender were used to detect leaky ultrasonic surface waves emanating from concrete. A normalized backscattered energy parameter was calculated from the signals. Statistically significant differences in the normalized backscattered energy were observed between concrete samples with varying levels of simulated and actual cracking damage volume. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Adhesive joint evaluation by ultrasonic interface and lamb waves

    Science.gov (United States)

    Rokhlin, S. I.

    1986-01-01

    Some results on the application of interface and Lamb waves for the study of curing of thin adhesive layers were summarized. In the case of thick substrates (thickness much more than the wave length) the interface waves can be used. In this case the experimental data can be inverted and the shear modulus of the adhesive film may be explicitly found based on the measured interface wave velocity. It is shown that interface waves can be used for the study of curing of structural adhesives as a function of different temperatures and other experimental conditions. The kinetics of curing was studied. In the case of thin substrates the wave phenomena are much more complicated. It is shown that for successful measurements proper selection of experimental conditions is very important. This can be done based on theoretical estimations. For correctly selected experimental conditions the Lamb waves may be a sensitive probe of adhesive bond quality and may be used or cure monitoring.

  9. Ultrahigh resolution endoscopic spectral domain optical coherence tomography with a tiny rotary probe driven by a hollow ultrasonic motor

    Science.gov (United States)

    Zhang, Ning; Chen, Tianyuan; Huo, Tiancheng; Wang, Chengming; Zheng, Jing-gao; Zhou, Tieying; Xue, Ping

    2013-03-01

    This paper proposes a novel rotary endoscopic probe for spectral-domain optical coherence tomography (SD-OCT). The probe with a large N.A. objective lens is driven by an ultra-small hollow rectangular ultrasonic motor for circular scanning. Compared to the conventional driven techniques, the hollow ultrasonic motor enables the fiber to pass through its inside. Therefore the fiber, the objective lens and the motor are all at the same side. This enables 360 degree unobstructed imaging without any shadow resulted from power wire as in the conventional motor-driven endoscopic OCT. Moreover, it shortens the length of the rigid tip and enhances the flexibility of the probe. Meanwhile, the ultrasonic motor is robust, simple, quiet and of high torque, very suitable for OCT endoscopic probe. The side length of the motor is 0.7 mm with 5mm in length. The outer diameter of the probe is 1.5mm. A significant improvement in the lateral resolution is demonstrated due to the novel design of the objective lens. A right-angle lens is utilized instead of the traditional right-angle prism as the last optics close to the sample, leading to a reduction of the working distance and an enlargement of the N.A. of the objective lens. It is demonstrated that the endoscopic SD-OCT system achieves an axial resolution of ~7μm, a lateral resolution of ~6μm and a SNR of ~96dB.

  10. Development of a radial-torsional vibration hybrid type ultrasonic motor with a hollow and short cylindrical structure.

    Science.gov (United States)

    Wang, Jian; Guo, Jifeng

    2009-05-01

    A longitudinal-torsional hybrid-type ultrasonic motor has larger torque and lower revolution speed compared with other kinds of ultrasonic motors. It drives devices directly and precisely, so it is adaptable to many fields, especially aeronautics and astronautics, as a servo actuator. Due to the different sound propagation speeds of longitudinal and torsional vibrations in the stator, it is difficult to match resonant frequencies of longitudinal and torsional vibrations. In this paper, a new radial-torsional vibration hybrid-type ultrasonic motor is put forward, which utilizes longitudinal vibration derived from radial vibration by the Poisson effect. The short, hollow cylindrical structure easily makes resonant frequencies of first-order radial and torsional vibrations into degeneracy. First, the new structure of the motor is presented. Second, the principle of matching the resonant frequencies is developed, and the motor geometry is optimized by ANSYS software. Finally, a 60-mm diameter prototype is fabricated, which performs well. The no-load velocity and maximum torque are 25 r/min and 5 N x m, respectively. This kind of motor is small, light, and noiseless.

  11. Ultrasonic guided wave based damage imaging by time-reversal method in frequency-wavenumber domain

    Science.gov (United States)

    Xu, C. G.; Xu, B. Q.; Luo, Y.; Xu, G. D.; Lu, L. Z.

    2017-05-01

    More attention has been drawn to ultrasonic guided waves (UGW) based damage detection method for its advantages of wide range inspection of large scale structures. However, complex propagation characteristics of guided waves as well as traditional contact ultrasonic transducers limit its application for the practical damage detection. By combining Scanning Laser Doppler vibrometer (SLDV) technology, Time-Reversal method in frequency-wavenumber domain (f-k RTM) can compensate for the dispersive nature of Lamb waves, localize multiple damage sites and identify their sizes without time consuming numerical calculation. In this work, we adopt f-k RTM for damage detection in plate-like structure. Instead of SLDV in experiment, 3D finite element numerical method is adopted to obtain scattered ultrasonic guided wavefield data with high spatial resolution. The direct path waves were extracted to obtain the incident wavefield while the scattered signals were used to calculate the scattering wave field. Damage imaging can also be achieved by introducing crosscorrelation imaging condition. Imaging results show that the method is very effective for crack localization and boundary shape-recognition. Numerical simulation results and imaging algorithm laid the foundation for the method applied in experiment and practice.

  12. Combination of nonlinear ultrasonics and guided wave tomography for imaging the micro-defects.

    Science.gov (United States)

    Li, Weibin; Cho, Younho

    2016-02-01

    The use of guided wave tomography has become an attractive alternative to convert ultrasonic wave raw data to visualized results for quantitative signal interpretation. For more accurate life prediction and efficient management strategies for critical structural components, there is a demand of imaging micro-damages in early stage. However, there is rarely investigation on guided wave tomographic imaging of micro-defects. One of the reasons for this might be that it becomes challenging to monitor tiny signal difference coefficient in a reliable manner for wave propagation in the specimens with micro-damages. Nonlinear acoustic signal whose frequency differs from that of the input signal can be found in the specimens with micro-damages. Therefore, the combination of guided wave tomography and nonlinear acoustic response induced by micro-damages could be a feasibility study for imaging micro-damages. In this paper, the nonlinear Rayleigh surface wave tomographic method is investigated to locate and size micro-corrosive defect region in an isotropic solid media. The variations of acoustic nonlinear responses of ultrasonic waves in the specimens with and without defects are used in guided wave tomographic algorithm to construct the images. The comparisons between images obtained by experimental signals and real defect region induced by hydrogen corrosion are presented in this paper. Results show that the images of defect regions with different shape, size and location are successfully obtained by this novel technique, while there is no visualized result constructed by conventional linear ultrasonic tomographic one. The present approach shows a potential for inspecting, locating and imaging micro-defects by nonlinear Rayleigh surface wave tomography. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Detection of Microcracks in Trunnion Rods Using Ultrasonic Guided Waves

    Science.gov (United States)

    2015-07-01

    image (Figure 1), a blue arrow has been drawn to indicate the fracture origin with white arrows drawn to indicate the crack propagating direction...The green ellipse encircles an area that appears to have been a pre-existing crack, which is more heavily oxidized than the rest of the fracture ... Tungsten 5200 19.4 101.0 Gallium 2740 5.9 16.3 Field’s metal 2617 7.8 20.6 4.3.2 Low melting point metals for ultrasonic coupling In searching for

  14. Optimization of ultrasonic transducers for selective guided wave actuation

    Science.gov (United States)

    Miszczynski, Mateusz; Packo, Pawel; Zbyrad, Paulina; Stepinski, Tadeusz; Uhl, Tadeusz; Lis, Jerzy; Wiatr, Kazimierz

    2016-04-01

    The application of guided waves using surface-bonded piezoceramic transducers for nondestructive testing (NDT) and Structural Health Monitoring (SHM) have shown great potential. However, due to difficulty in identification of individual wave modes resulting from their dispersive and multi-modal nature, selective mode excitement methods are highly desired. The presented work focuses on an optimization-based approach to design of a piezoelectric transducer for selective guided waves generation. The concept of the presented framework involves a Finite Element Method (FEM) model in the optimization process. The material of the transducer is optimized in topological sense with the aim of tuning piezoelectric properties for actuation of specific guided wave modes.

  15. Contact mode and force transferring model of cylindrical ultrasonic motor with bending vibration mode

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; GUO Jifeng

    2008-01-01

    Cylindrical Ultrasonic Motor (CUSM)can be widely used in many fields such as zoom and focus system of cameras,electric curtain and micro-driver of MEMS.This work concentrates on the single-point and the double-point contact modes between the stator and the rotor.which are proved by theory and experiment.There is a critical point of the pre-pressure.When the pre-pressure is below the critical point.the single-point model is suitable;otherwise the double-point model is appropriate.Then the force transferring model is analyzed,and expressions of mechanical characteristics and efficiency of the motor axe put forward.Simulation results are confirmed by experimental ones,which shows that the model is well suited to guide design of the motor.Finally a φ14 mm prototype was fabricated.Its maximum torque is 0.11 Nm.and the no-load speed is about 300 r/min.

  16. Warped Wigner-Hough Transform for Defect Reflection Enhancement in Ultrasonic Guided Wave Monitoring

    Directory of Open Access Journals (Sweden)

    Luca De Marchi

    2012-01-01

    Full Text Available To improve the defect detectability of Lamb wave inspection systems, the application of nonlinear signal processing was investigated. The approach is based on a Warped Frequency Transform (WFT to compensate the dispersive behavior of ultrasonic guided waves, followed by a Wigner-Ville time-frequency analysis and the Hough Transform to further improve localization accuracy. As a result, an automatic detection procedure to locate defect-induced reflections was demonstrated and successfully tested by analyzing numerically simulated Lamb waves propagating in an aluminum plate. The proposed method is suitable for defect detection and can be easily implemented for real-world structural health monitoring applications.

  17. Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

    Science.gov (United States)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  18. Detecting Lamb waves with broadband acousto-ultrasonic signals in composite structures

    Science.gov (United States)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and lowest antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave disperison curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMCs, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  19. Ultrasonic Guided Waves in Piezoelectric Layered Composite with Different Interfacial Properties

    Directory of Open Access Journals (Sweden)

    Xiao Chen

    2011-01-01

    Full Text Available Combining the propagation model of guided waves in a multilayered piezoelectric composite with the interfacial model of rigid, slip, and weak interfaces, the generalized dispersion characteristic equations of guided waves propagating in a piezoelectric layered composite with different interfacial properties are derived. The effects of the slip, weak, and delamination interfaces in different depths on the dispersion properties of the lowest-order mode ultrasonic guided wave are analyzed. The theory would be used to characterize the interfacial properties of piezoelectric layered composite nondestructively.

  20. Inverse method for the determination of elastic properties of coating layers by the surface ultrasonic waves

    Institute of Scientific and Technical Information of China (English)

    CHANG Jun; YANG Zhen; XU Jin-quan

    2005-01-01

    As the coated materials are widely applied in engineering, estimation of the elastic properties of coating layers is of great practical importance. This paper presents an inversion algorithm for determining the elastic properties of coating layers from the given velocity dispersion of surface ultrasonic waves. Based on the dispersive equation of surface waves in layered half space,an objective function dependent on coating material parameters is introduced. The density and wave velocities, which make the object function minimum, are taken as the inversion results. Inverse analyses of two parameters (longitudinal and transverse velocities) and three parameters (the density, longitudinal and transverse velocities) of the coating layer were made.

  1. Removal of Liquid Leaked into Narrow Channel Using High-Intensity Aerial Ultrasonic Waves

    Science.gov (United States)

    Ito, Youichi; Kotani, Masayuki

    2004-05-01

    We tried to remove a liquid leaked into a narrow channel immediately by radiating high-intensity aerial ultrasonic waves (at a frequency of 20 kHz) onto the liquid to atomize and disperse it into the atmosphere. Channels of 0.3 to 2 mm width and 1 to 10 mm depth with and without a bottom were used. The results of experiments showed that an ultrasonic radiation of 170 dB or more could remove a liquid in each of the channels immediately, by atomizing and dispersing it. The processes of atomization and dispersion of the liquid in each channel without a bottom largely varied, depending on the channel width and depth as well as the ultrasonic radiation intensity.

  2. Ultrasonic probe deployment device for increased wave transmission and rapid area scan inspections

    Science.gov (United States)

    DiMambro, Joseph [Placitas, NM; Roach, Dennis P [Albuquerque, NM; Rackow, Kirk A [Albuquerque, NM; Nelson, Ciji L [Albuquerque, NM; Dasch, Cameron J [Boomfield Hills, MI; Moore, David G [Albuquerque, NM

    2012-01-03

    An ultrasonic probe deployment device in which an ultrasound-transmitting liquid forms the portion of the ultrasonic wave path in contact with the surface being inspected (i.e., the inspection surface). A seal constrains flow of the liquid, for example preventing the liquid from surging out and flooding the inspection surface. The seal is not rigid and conforms to variations in the shape and unevenness of the inspection surface, thus forming a seal (although possibly a leaky seal) around the liquid. The probe preferably is held in place to produce optimum ultrasonic focus on the area of interest. Use of encoders can facilitate the production of C-scan area maps of the material being inspected.

  3. Friction Behavior on Contact Interface of Linear Ultrasonic Motor with Hard Contact Materials

    Institute of Scientific and Technical Information of China (English)

    Wang Jinpeng; Zhou Hongping; Jin Jiamei; Zhao Chunsheng

    2015-01-01

    How to improve the efficiency of the linear ultrasonic motor with hard contact materials (HLUSM ) or the precision motion stage driven by HLUSM ,becomes a hot issue .Analysis and testing of friction behavior on the contact interface of HLUSM is one of the key issues .Under the action of ultrasonic vibration and impact ,the fric-tion behavior on contact interface is very complex due to micro-amplitude and high frequency .Moreover ,it is diffi-cult to observe and test it .Focusing on the frictional behavior on the interface of HLUSM ,a new method ,through testing the vibration of the driving tips (scanning vibrometer PSV-400-3D) and the motion of the slider (displace-ment sensor LK-G30) ,respectively ,is proposed .Then ,take the HLUSM as an example ,theoretical analyses and experiments are carried out .Theoretical analysis shows that the average speed of the slider should be 600 mm/s when there is no slippage between the stator and slider during the contact process .Experimental results show that the average speed of the slider is about 390 mm/s .At the same time ,the tangential vibration speed of the driving tip of HLUSM is larger than 600 mm/s .Therefore ,there must be slippage between the stator and slider of HLUSM .Further experimental results show that the maximum efficiency is less than 10% .The slippage on the contact interface should be the main reason for the low efficiency of HLUSM .

  4. Elastic constants measurement of anisotropic Olivier wood plates using air-coupled transducers generated Lamb wave and ultrasonic bulk wave.

    Science.gov (United States)

    Dahmen, Souhail; Ketata, Hassiba; Ben Ghozlen, Mohamed Hédi; Hosten, Bernard

    2010-04-01

    A hybrid elastic wave method is applied to determine the anisotropic constants of Olive wood specimen considered as an orthotropic solid. The method is based on the measurements of the Lamb wave velocities as well as the bulk ultrasonic wave velocities. Electrostatic, air-coupled, ultrasonic transducers are used to generate and receive Lamb waves which are sensitive to material properties. The variation of phase velocity with frequency is measured for several modes propagating parallel and normal to the fiber direction along a thin Olivier wood plates. A numerical model based mainly on an optimization method is developed; it permits to recover seven out of nine elastic constants with an uncertainty of about 15%. The remaining two elastic constants are then obtained from bulk wave measurements. The experimental Lamb phase velocities are in good agreement with the calculated dispersion curves. The evaluation of Olive wood elastic properties has been performed in the low frequency range where the Lamb length wave is large in comparison with the heterogeneity extent. Within the interval errors, the obtained elastic tensor doesn't reveal a large deviation from a uniaxial symmetry.

  5. Design and characteristic analysis of L1B4 ultrasonic motor considering contact mechanism.

    Science.gov (United States)

    Rho, Jong-Seok; Kim, Byung-Jai; Lee, Chang-Hwan; Joo, Hyun-Woo; Jung, Hyun-Kyo

    2005-11-01

    Up to the present time, the analysis and design of ultrasonic motors (USMs) have been performed using rough analytic methods or commercial analysis tools without considering the complex contact mechanisms. As a result, it was impossible to achieve an exact analysis and design of a USM. In order to address the problem, we proposed the analysis and design methodology of an L1B4 USM using a three-dimensional finite element method combined with an analytic method that considers complex contact mechanisms in linear operation. This methodology is applicable to many other kinds of USMs which use resonance modes and contact mechanisms. Also, we designed and prototyped the mechanical system and driving circuit of the L1B4 USM, and finally validated the proposed analysis and design methodology by comparing their outcomes with experimental data.

  6. FRIT for Systems with Dead-Zone and Its Application to Ultrasonic Motors

    Science.gov (United States)

    Wakasa, Yuji; Kanagawa, Shinji; Tanaka, Kanya; Nishimura, Yuki

    Ultrasonic motors (USMs) intrinsically have a dead-zone property which is sensitive to load changes. This paper proposes a fictitious reference iterative tuning (FRIT) method for systems with a dead-zone property such as USMs. The standard FRIT method is basically developed for linear systems and may not give a satisfactory control performance for noninvertible nonlinear systems including USMs. In contrast, the proposed FRIT method can achieve such a performance by introducing a right inverse of a dead-zone function as a dead-zone compensator. In the optimization process of FRIT, the so-called covariance matrix adaptation evolution strategy (CMA-ES) is used for simultaneously searching a dead-zone parameter as well as controller parameters. CMA-ES is a kind of stochastic multi-point search techniques and is effective for nondifferentiable and nonconvex optimization problems. Experimental results for a USM are given to show the effectiveness of the proposed method.

  7. Analysis of Radiation Beam of a Leaky Lamb Wave in Ultrasonic Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Y. S.; Bae, J. H.; Park, C. G.; Lee, J. H.

    2010-02-15

    The theoretical and experimental study of the propagation and radiation of leaky Lamb wave in a plate waveguide sensor has been carried out. In the plate waveguide sensor, the A{sub 0} leaky Lamb wave is utilized for the single mode generation and the effective radiation capability in a fluid. The plate waveguide sensor which consists of a plate waveguide, a teflon wedge and an ultrasonic sensor has been designed and manufactured. The tone-burst excitation of high power long pulse should be applied to minimize the dispersion effect in 10 m long distance propagation of the A{sub 0} Lamb wave. A novel technique which is capable of steering a radiation beam of a waveguide sensor without a mechanical movement can be achieved by a frequency tuning method of the excitation pulse in the dispersive low frequency range of the A{sub 0} Lamb wave. The characteristics of radiation beam of ultrasonic waveguide sensors has been investigated by the beam profile measurements according to the plate thickness, the radiation aperture length, the pulse cycles and the excitation frequency. The design parameters of the plate waveguide sensor has been optimized. The C-scanning experiments in water have been carried out for the performance of the optimized ultrasonic waveguide sensor. The poulsbility of C-scan visualization using the plate waveguide sensor has been verified

  8. Estimation of in-situ stresses in concrete members using polarized ultrasonic shear waves

    Science.gov (United States)

    Chen, Andrew; Schumacher, Thomas

    2014-02-01

    Ultrasonic testing is commonly used to detect flaws, estimate geometries, and characterize properties of materials and structures. Acoustoelasticity refers to the dependency of stress wave velocity with applied stresses and is a phenomenon that has been known by geophysicists since the 1960s. A way to capitalize on this effect for concrete applications is by using ultrasonic shear waves which are particularly sensitive to applied stresses when polarized in the direction of the applied stress. The authors conducted an experiment on a 150 mm (6 in.) diameter concrete cylinder specimen with a length of 305 mm (12 in.) that was loaded in discrete load steps to failure. At each load step two ultrasonic shear waves were transmitted through the specimen, one with the polarization perpendicular and the other transverse to the applied stress. The velocity difference between the two sets of polarized shear waves was found to correlate with the applied stress in the specimen. Two potential applications for this methodology include estimation of stresses in pre-stressed concrete bridge girders and investigation of load redistribution in structural support elements after extreme events. This paper introduces the background of the methodology, presents an analysis of the collected data, and discusses the relationship between the recorded signals and the applied stress.

  9. 平面超声波电动机的研究%Research on Planar Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    王京山; 赵学涛

    2013-01-01

    A new type of planar ultrasonic motor was proposed.Motor using cross longitudinal and bending hybrid Langevin transducer was single stator structure.Four drive foot was located at the first bending standing wave of antinode place of the corresponding end.By means of finite element method,the longitudinal and bending vibration characteristic frequency influence trend by its structure parameters was analysed,and frequencies were degenerated to 22463 Hz by adjusting the structural parameter.Drive foot trajectory mathematical model was established,and transient analysis was developed to gain the vibration trajectories of nodes on the driving food,which verified the correctness of the founded vibration trajectory equation.%提出了一种新型平面超声波电动机.电动机采用单定子十字正交纵弯夹心换能器结构,4个驱动足位于相应端部第一个弯曲驻波的波腹处.借助有限元法,分析电机结构参数对纵振和弯振特征频率的影响趋势,调整结构参数将纵弯模态特征频率简并至22463 Hz.建立驱动足运动轨迹的数学模型,借助有限元瞬态分析,对驱动足振动轨迹进行仿真,实现对所建立振动轨迹数学模型的验证.

  10. Modeling of ultrasonic wave propagation in composite laminates with realistic discontinuity representation.

    Science.gov (United States)

    Zelenyak, Andreea-Manuela; Schorer, Nora; Sause, Markus G R

    2017-06-20

    This paper presents a method for embedding realistic defect geometries of a fiber reinforced material in a finite element modeling environment in order to simulate active ultrasonic inspection. When ultrasonic inspection is used experimentally to investigate the presence of defects in composite materials, the microscopic defect geometry may cause signal characteristics that are difficult to interpret. Hence, modeling of this interaction is key to improve our understanding and way of interpreting the acquired ultrasonic signals. To model the true interaction of the ultrasonic wave field with such defect structures as pores, cracks or delamination, a realistic three dimensional geometry reconstruction is required. We present a 3D-image based reconstruction process which converts computed tomography data in adequate surface representations ready to be embedded for processing with finite element methods. Subsequent modeling using these geometries uses a multi-scale and multi-physics simulation approach which results in quantitative A-Scan ultrasonic signals which can be directly compared with experimental signals. Therefore, besides the properties of the composite material, a full transducer implementation, piezoelectric conversion and simultaneous modeling of the attached circuit is applied. Comparison between simulated and experimental signals provides very good agreement in electrical voltage amplitude and the signal arrival time and thus validates the proposed modeling approach. Simulating ultrasound wave propagation in a medium with a realistic shape of the geometry clearly shows a difference in how the disturbance of the waves takes place and finally allows more realistic modeling of A-scans. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Ultrasonic wave propagation on an inclined solid half-space partially immersed in a liquid

    Science.gov (United States)

    Dao, Cac Minh

    The interaction between a bounded ultrasonic beam and a liquid wedge over a solid half-space is studied theoretically as well as experimentally. A semi-analytical technique called Distributed Point Source Method (DPSM) is adopted for modeling the ultrasonic field in a wedge-shaped fluid structure on a solid half-space. This study is important for analyzing and understanding the propagation of ultrasonic waves used for underwater communications and inspections. A better understanding of the elastic wave propagation in water and in submerged marine strata near the seashore requires extensive investigations of such problem geometries. The semi-analytical technique used in this dissertation considers a bounded acoustic beam striking a fluid-solid interface between a fluid wedge and a solid half-space. Solution of this problem is beyond the scope of the currently available analytical methods when the beam is bounded. However, it is important to model the bounded beams because, in all underwater communications and inspections, bounded beams are used. Currently, only numerical method [Boundary Element Method (BEM) or Finite Element Method (FEM)] based packages (e.g., PZFlex) are in principle capable of modeling ultrasonic fields in such structures. However, these packages are not very accurate and are very CPU-intensive for high-frequency ultrasonic problems. At high frequencies, FEM- and BEM-based packages require huge amount of computation memory and time for their executions that the DPSM technique can avoid. The effect of the angle variation between the fluid-solid interface and the fluid wedge on the wave propagation characteristics is studied and presented.

  12. Shear waves in vegetal tissues at ultrasonic frequencies

    Science.gov (United States)

    Fariñas, M. D.; Sancho-Knapik, D.; Peguero-Pina, J. J.; Gil-Pelegrín, E.; Gómez Álvarez-Arenas, T. E.

    2013-03-01

    Shear waves are investigated in leaves of two plant species using air-coupled ultrasound. Magnitude and phase spectra of the transmission coefficient around the first two orders of the thickness resonances (normal and oblique incidence) have been measured. A bilayer acoustic model for plant leaves (comprising the palisade parenchyma and the spongy mesophyll) is proposed to extract, from measured spectra, properties of these tissues like: velocity and attenuation of longitudinal and shear waves and hence Young modulus, rigidity modulus, and Poisson's ratio. Elastic moduli values are typical of cellular solids and both, shear and longitudinal waves exhibit classical viscoelastic losses. Influence of leaf water content is also analyzed.

  13. The Recent Development and Application of Ultrasonic Motors%超声波电动机发展现状及应用

    Institute of Scientific and Technical Information of China (English)

    罗辞勇; 卢斌; 张帆; 蔡珍珍

    2011-01-01

    Ultrasonic motor has unique advantages in the applications of precision instruments aerospace and other high -end areas. The basic principle of ultrasonic motors and structure were described. The development prospects, advantages and disadavantages of ultrasonic motor were analysed, The mathematical model of the ultrasonic motor, motor structure, motor control,the direction of further research and improvement tools were given. The ultrasonic motor applications were introduced as well as the future direction of ultrasonic motor.%超声波电动机在精密仪器、航空航天等高端应用领域有其独特的优势.首先对超声波电动机的基本原理和结构进行了描述;然后对超声波电动机的发展现状、发展前景,以及超声波电动机的优缺点作了详细的分析,并指出了超声波电动机在数学模型、电机机构、电机控制等方向需要进一步研究和改善的手段;最后给出了超声波电动机的一些应用领域,以及超声波电动机的未来发展方向.

  14. An experimental study on the coalescence process of binary droplets in oil under ultrasonic standing waves.

    Science.gov (United States)

    Luo, Xiaoming; Cao, Juhang; He, Limin; Wang, Hongping; Yan, Haipeng; Qin, Yahua

    2017-01-01

    The coalescence process of binary droplets in oil under ultrasonic standing waves was investigated with high-speed photography. Three motion models of binary droplets in coalescence process were illustrated: (1) slight translational oscillation; (2) sinusoidal translational oscillation; (3) migration along with acoustic streaming. To reveal the droplets coalescence mechanisms, the influence of main factors (such as acoustic intensity, droplet size, viscosity and interfacial tension, etc) on the motion and coalescence of binary droplets was studied under ultrasonic standing waves. Results indicate that the shortest coalescence time is achieved when binary droplets show sinusoidal translational oscillation. The corresponding acoustic intensity in this case is the optimum acoustic intensity. Under the optimum acoustic intensity, drop size decrease will bring about coalescence time decrease by enhancing the binary droplets oscillation. Moreover, there is an optimum interfacial tension to achieve the shortest coalescence time.

  15. FBG-based ultrasonic wave detection and acoustic emission linear location system

    Science.gov (United States)

    Jiang, Ming-shun; Sui, Qing-mei; Jia, Lei; Peng, Peng; Cao, Yuqiang

    2012-05-01

    The ultrasonic (US) wave detection and an acoustic emission (AE) linear location system are proposed, which employ fiber Bragg gratings (FBGs) as US wave sensors. In the theoretical analysis, the FBG sensor response to longitudinal US wave is investigated. The result indicates that the FBG wavelength can be modulated as static case when the grating length is much shorter than US wavelength. The experimental results of standard sinusoidal and spindle wave test agree well with the generated signal. Further research using two FBGs for realizing linear location is also achieved. The maximum linear location error is obtained as less than 5 mm. FBG-based US wave sensor and AE linear location provide useful tools for specific requirements.

  16. FBG-based ultrasonic wave detection and acoustic emission linear location system

    Institute of Scientific and Technical Information of China (English)

    JIANG Ming-shun; SUI Qing-mei; JIA Lei; PENG Peng; CAO Yu-qiang

    2012-01-01

    The ultrasonic (US) wave detection and an acoustic emission (AE) linear location system are proposed,which employ fiber Bragg gratings (FBGs) as US wave sensors.In the theoretical analysis,the FBG sensor response to longitudinal US wave is investigated.The result indicates that the FBG wavelength can be modulated as static case when the grating length is much shorter than US wavelength.The experimental results of standard sinusoidal and spindle wave test agree well with the generated signal.Further research using two FBGs for realizing linear location is also achieved.The maximumlinear location error is obtained as less than 5 mm.FBG-based US wave sensor and AE linear location provide useful tools for specific requirements.

  17. Effects of pore fluids in the subsurface on ultrasonic wave propagation

    Energy Technology Data Exchange (ETDEWEB)

    Seifert, Patricia Katharina [Univ. of California, Berkeley, CA (United States)

    1998-05-01

    This thesis investigates ultrasonic wave propagation in unconsolidated sands in the presence of different pore fluids. Laboratory experiments have been conducted in the sub-MHz range using quartz sand fully saturated with one or two liquids. Elastic wave propagation in unconsolidated granular material is computed with different numerical models: in one-dimension a scattering model based on an analytical propagator solution, in two dimensions a numerical approach using the boundary integral equation method, in three dimensions the local flow model (LFM), the combined Biot and squirt flow theory (BISQ) and the dynamic composite elastic medium theory (DYCEM). The combination of theoretical and experimental analysis yields a better understanding of how wave propagation in unconsolidated sand is affected by (a) homogeneous phase distribution; (b) inhomogeneous phase distribution, (fingering, gas inclusions); (c) pore fluids of different viscosity; (d) wettabilities of a porous medium. The first study reveals that the main ultrasonic P-wave signatures, as a function of the fraction on nonaqueous-phase liquids in initially water-saturated sand samples, can be explained by a 1-D scattering model. The next study investigates effects of pore fluid viscosity on elastic wave propagation, in laboratory experiments conducted with sand samples saturated with fluids of different viscosities. The last study concentrates on the wettability of the grains and its effect on elastic wave propagation and electrical resistivity.

  18. Simulation of ultrasonic lamb wave generation, propagation and detection for a reconfigurable air coupled scanner.

    Science.gov (United States)

    Dobie, Gordon; Spencer, Andrew; Burnham, Kenneth; Pierce, S Gareth; Worden, Keith; Galbraith, Walter; Hayward, Gordon

    2011-04-01

    A computer simulator, to facilitate the design and assessment of a reconfigurable, air-coupled ultrasonic scanner is described and evaluated. The specific scanning system comprises a team of remote sensing agents, in the form of miniature robotic platforms that can reposition non-contact Lamb wave transducers over a plate type of structure, for the purpose of non-destructive evaluation (NDE). The overall objective is to implement reconfigurable array scanning, where transmission and reception are facilitated by different sensing agents which can be organised in a variety of pulse-echo and pitch-catch configurations, with guided waves used to generate data in the form of 2-D and 3-D images. The ability to reconfigure the scanner adaptively requires an understanding of the ultrasonic wave generation, its propagation and interaction with potential defects and boundaries. Transducer behaviour has been simulated using a linear systems approximation, with wave propagation in the structure modelled using the local interaction simulation approach (LISA). Integration of the linear systems and LISA approaches are validated for use in Lamb wave scanning by comparison with both analytic techniques and more computationally intensive commercial finite element/difference codes. Starting with fundamental dispersion data, the paper goes on to describe the simulation of wave propagation and the subsequent interaction with artificial defects and plate boundaries, before presenting a theoretical image obtained from a team of sensing agents based on the current generation of sensors and instrumentation.

  19. Study of Atomization of a Water Jet by High-Intensity Aerial Ultrasonic Waves

    Science.gov (United States)

    Ito, Youichi

    2001-05-01

    An experimental study has been carried out on the atomization of a water jet by aerially radiating it with high-intensity ultrasonic waves. A sound source that enables the linear generation of high-intensity aerial ultrasonic waves (frequency: approximately 20 kHz) is combined with a cylindrical reflection plate in order to create a standing-wave sound field. An attempt has been made to atomize a water jet of 1 mm diameter by passing it through the above sound field at a velocity of approximately 30 m/s. It has been clarified that nodes of sound pressure in the standing-wave sound field are effective for the atomization of a water jet. In addition, the atomizing phenomenon of a water jet has been observed precisely. The relation between the intensity of sound waves required for atomization and the radiation duration has also been clarified. Even the radiation of sound waves for only 2 ms atomizes water. This suggests that a very fast water jet at 300-500 m/s might be atomized.

  20. IMMUNOBIOLOGICAL characteristic of tetanus toxoid fractions before and after exposure to ultrasonic waves

    Directory of Open Access Journals (Sweden)

    Plugator TN

    2012-10-01

    Full Text Available Fractional composition of industrial tetanus toxoid before and after exposure to ultrasonic waves was determined with the use of gel filtration chromatography. It was established, that with the exception of specific antigenic structures (fraction A, tetanus toxoid contained ballast proteins (fraction B. Ultrasound treatment of tetanus toxoid resulted in ballast proteins quantity decrease. Percentage composition of tetanus toxoid fractions depended on ultrasound treatment conditions.

  1. Dynamic Stimulation of Superconductivity With Resonant Terahertz Ultrasonic Waves

    CERN Document Server

    Kadin, Alan M

    2016-01-01

    An experiment is proposed to stimulate a superconducting thin film with terahertz (THz) acoustic waves, which is a regime not previously tested. For a thin film on a piezoelectric substrate, this can be achieved by coupling the substrate to a tunable coherent THz electromagnetic source. Suggested materials for initial tests are a niobium film on a quartz substrate, with a BSCCO intrinsic Josephson junction (IJJ) stack. This will create acoustic standing waves on the nm scale in the thin film. A properly tuned standing wave will enable electron diffraction across the Fermi surface, leading to electron localization perpendicular to the substrate. This is expected to reduce the effective dimensionality, and enhance the tendency for superconducting order parallel to the substrate, even well above the superconducting critical temperature. This enhancement can be observed by measuring the in-plane critical current and the perpendicular tunneling gap. A similar experiment may be carried out for a cuprate thin film, ...

  2. Measuring the Temperature Increase of an Ultrasonic Motor in a 3-Tesla Magnetic Resonance Imaging System

    Directory of Open Access Journals (Sweden)

    Peyman Shokrollahi

    2017-06-01

    Full Text Available This paper aims to evaluate the temperature increase caused by a 3.0-T magnetic resonance imaging (MRI system on an ultrasonic motor (USM used to actuate surgical robots in the MRI environment. Four fiber-optic temperature sensors were attached to the USM. Temperature was monitored outside the five-Gauss boundary and then inside the bore for 20 min while the USM was powered on. The USM temperature was tested for two states of the scanner, “off” and “on”, by employing common clinical imaging sequences and echo planar imaging sequences. The USM showed a slight temperature increase while operating in the static field of the MRI. A considerable temperature increase (~10 °C was observed when the scanner was on. The temperature increased to 60 °C, which is beyond the acceptable safe temperature and can result in thermal burns. Most of the temperature increase (80% was due to effects of the static field on the motion of the rotating parts of the motor, while the remainder (20% derived from heat deposited in the conductive components of the USM due to radiofrequency pulses and gradient field changes. To solve the temperature increase, the metal components of the USM’s case can be replaced by silicon carbide.

  3. Study on spherical stator for multidegree-of-freedom ultrasonic motor

    Science.gov (United States)

    Nakajima, Shuta; Kajiwara, Hidekazu; Aoyagi, Manabu; Tamura, Hideki; Takano, Takehiro

    2016-07-01

    A multidegree-of-freedom ultrasonic motor (MDOF-USM) has excellent features such as high torque at a low speed and a self-holding force, compared with other types of MDOF motor. Therefore, the MDOF-USM has been considered for applications in robot joints, multidimensional systems, and spacecraft. In previous research, the MDOF-USM consisting of a spherical rotor and a stator vibrator of various shapes has been mainly studied. In contrast, the MDOF-USM consisting of a spherical stator and a rotor of various shapes is proposed in this paper. The excitation methods for vibration modes and mode rotation using piezoelectric plates and multilayered piezoelectric actuators were examined. Furthermore, a stator support method that does not significantly affect the vibration of the sphere was devised. From the results of experiments using the fabricated prototype stator, the generation of vibration mode and mode rotation were confirmed. Therefore, the possibility of the realization of the MDOF-USM using a spherical stator was indicated.

  4. Developing the new method measuring thickness and quality of bottom sediments in using ultrasonic wave

    Science.gov (United States)

    Ishikawa, Tomonari; Matsumoto, Yoshitaka; Hozumi, Naohiro

    2017-07-01

    Measuring the quality and thickness of bottom sediment that it causes some environmental problem, the shortage of water storage volume and anaerobic zone in the bottom of reservoirs, takes huge costs and long time. The purpose of our research is to develop a new method to measure the thickness and size characteristics of bottom sediment using ultrasonic waves that allow obtaining the quality of it indirectly. This new method applies the echo characteristic of bottom sediment in each particle size using the higher frequency than another method, which uses for measuring geological layer at seabed survey. In this research, we attempted to estimate the particle size of bottom sediment by ultrasonic waves irradiating from two different directions such as horizontal and vertical direction, and compare these experiments. We use sediment that we sampled from the lake bottom classified by particle size. At first, we acquired the results that show a relation between particle size and intensity; the obtained echo intensities, which were observed with oscilloscope, were changed depending on the particle sizes. In addition, peaks, which were obtained by power spectrum analysis, appeared on the same frequency band even though the different particle size. However the relation between the experiments of horizontal and vertical direction is not clear. This research indicated the possibility of estimating the characteristics of each particle size in bottom sediment by ultrasonic waves.

  5. Ultrasonic Guided Wave Method For Crack Detection In Buried Plastic Pipe

    Directory of Open Access Journals (Sweden)

    Wan Hamat Wan Sofian

    2016-01-01

    Full Text Available Plastic pipe are widely used in many fields for the fluid or gaseous product conveyance but basic components of a plastic material made it very sensitive to damage, which requires techniques for detecting damage reliable and efficient. Ultrasonic guided wave is a sensitive method based on propagation of low-frequency excitation in solid structures for damage detection. Ultrasonic guided wave method are performed to investigate the effect of crack to the frequency signal using Fast Fourier Transform (FFT analysis. This paper researched to determine performance of ultrasonic guided wave method in order to detect crack in buried pipeline. It was found that for an uncrack pipe, FFT analysis shows one peak which is the operating frequency by the piezoelectric actuator itself while the FFT analysis for single cracked pipe shows two peak which is the operating frequency by the piezoelectric actuator itself and the resultant frequency from the crack. For multi cracked pipe, the frequency signal shows more than two peak depend the number of crack. The results presented here may facilitate improvements in the accuracy and precision of pipeline crack detection.

  6. Test and Analyze System for Ultrasonic Motor%超声电机测试分析系统

    Institute of Scientific and Technical Information of China (English)

    武威; 张铁民

    2012-01-01

    超声电机是一种新型的直接驱动电机,超声电机特性测试是实现其控制的基础.利用虚拟仪器技术构建超声电机的检测与分析系统,实现对旋转和直线超声电机稳态和瞬态过程电压、电流、速度等多参量的测试与分析,构建稳定、可靠的测试平台.检测系统结构简单,具有一定的通用性和可行性.%Ultrasonic Motor (USM) is a new kind of direct driving motor, characteristic test of USM is the base of control. A testing and analyzing system of USM was built by virtual instruments, it realized testing and analyzing multi-parameter, such as voltage, current, and votary etc. of rotary ultrasonic motor and linear ultrasonic motor, in process of steady state and transient, and built a stable and reliable test platform. The system is simple, practical and feasible.

  7. Rainbow trapping of ultrasonic guided waves in chirped phononic crystal plates.

    Science.gov (United States)

    Tian, Zhenhua; Yu, Lingyu

    2017-01-05

    The rainbow trapping effect has been demonstrated in electromagnetic and acoustic waves. In this study, rainbow trapping of ultrasonic guided waves is achieved in chirped phononic crystal plates that spatially modulate the dispersion, group velocity, and stopband. The rainbow trapping is related to the progressively slowing group velocity, and the extremely low group velocity near the lower boundary of a stopband that gradually varies in chirped phononic crystal plates. As guided waves propagate along the phononic crystal plate, waves gradually slow down and finally stop forward propagating. The energy of guided waves is concentrated at the low velocity region near the stopband. Moreover, the guided wave energy of different frequencies is concentrated at different locations, which manifests as rainbow guided waves. We believe implementing the rainbow trapping will open new paradigms for guiding and focusing of guided waves. Moreover, the rainbow guided waves with energy concentration and spatial separation of frequencies may have potential applications in nondestructive evaluation, spatial wave filtering, energy harvesting, and acoustofluidics.

  8. Numerical and experimental investigation of nonlinear ultrasonic Lamb waves at low frequency

    Science.gov (United States)

    Zuo, Peng; Zhou, Yu; Fan, Zheng

    2016-07-01

    Nonlinear ultrasonic Lamb waves are popular to characterize the nonlinearity of materials. However, the widely used nonlinear Lamb mode suffers from two associated complications: inherent dispersive and multimode natures. To overcome these, the symmetric Lamb mode (S0) at low frequency region is explored. At the low frequency region, the S0 mode is little dispersive and easy to generate. However, the secondary mode still exists, and increases linearly for significant distance. Numerical simulations and experiments are used to validate the nonlinear features and therefore demonstrate an easy alternative for nonlinear Lamb wave applications.

  9. Study of the Effects of Ultrasonic Waves on the Reproductive Integrity of Mammalian Cells Cultured in Vitro

    Science.gov (United States)

    Martins, B. I.

    1971-01-01

    The effects of monochromatic ultrasonic waves of 0.1, 0.5, 1.0, 2.0 and, 3.3 MHz frequency on the colony-forming ability of mammalian cells (M3-1,V79, Chang's and T-1) cultured in vitro have been studied to determine the nature of the action of ultrasonic energy on biological systems at the cellular level. The combined effect of ultrasound and X-rays has also been studied. It is concluded: (1) Ultrasonic irradiation causes both lethal and sublethal damage. (2) There is a threshold dose rate for lethal effects. (3) The effectiveness of ultrasonic waves in causing cell death probably depends on the frequency and the amplitude of the waves for a given cell line, indicating a possible resonance phenomenon.

  10. Low-cost ultrasonic lamb-wave transducer

    Science.gov (United States)

    Kammerer, C. C.

    1978-01-01

    Transducer propagates Lamb wave through thin aluminum sheet material. Model includes two elements that measure effects of damping and loading which, in turn, are indirectly equated to bond integrity. Transducer has been used to evaluate bond integrity of aluminum facing adhesively bonded to aluminum facing. Because of versatility, it is now possible to inspect many objects of different configurations that could not be reached with earlier transducers.

  11. Quantitative Diagnostics of Multilayered Composite Structures with Ultrasonic Guided Waves

    Science.gov (United States)

    2014-09-01

    the material. The excitation signal applied to the transmitter was a 12 cycles of sinusoidal toneburst with a frequency of 210 kHz. An improved image...were launched from the outer surfaces of the test specimens by using acrylic coupling shoes . In this way, the guided wave energy was launched through...the tip section of the shoe and subsequently propagating along the surface of the test specimen. Time domain signal processing was applied to analyze

  12. An ultrasonic guided wave method to estimate applied biaxial loads

    Science.gov (United States)

    Shi, Fan; Michaels, Jennifer E.; Lee, Sang Jun

    2012-05-01

    Guided waves propagating in a homogeneous plate are known to be sensitive to both temperature changes and applied stress variations. Here we consider the inverse problem of recovering homogeneous biaxial stresses from measured changes in phase velocity at multiple propagation directions using a single mode at a specific frequency. Although there is no closed form solution relating phase velocity changes to applied stresses, prior results indicate that phase velocity changes can be closely approximated by a sinusoidal function with respect to angle of propagation. Here it is shown that all sinusoidal coefficients can be estimated from a single uniaxial loading experiment. The general biaxial inverse problem can thus be solved by fitting an appropriate sinusoid to measured phase velocity changes versus propagation angle, and relating the coefficients to the unknown stresses. The phase velocity data are obtained from direct arrivals between guided wave transducers whose direct paths of propagation are oriented at different angles. This method is applied and verified using sparse array data recorded during a fatigue test. The additional complication of the resulting fatigue cracks interfering with some of the direct arrivals is addressed via proper selection of transducer pairs. Results show that applied stresses can be successfully recovered from the measured changes in guided wave signals.

  13. High-frequency guided ultrasonic waves for hidden defect detection in multi-layer aircraft structures

    Science.gov (United States)

    Masserey, B.; Raemy, C.; Fromme, P.

    2012-05-01

    Aerospace structures contain multi-layer components subjected to cyclic loading conditions; fatigue cracks and disbonds can develop, often at fastener holes. High-frequency guided waves have the potential for non-destructive damage detection at critical and difficult to access locations from a stand-off distance. Using commercially available ultrasonic transducers, high frequency guided waves were generated that penetrate through the complete thickness of a model structure, consisting of two adhesively bonded aluminum plates. The wave propagation along the specimen was measured and quantified using a laser interferometer. The wave propagation and scattering at internal defects was simulated using Finite Element (FE) models and good agreement with the measurement results found. The detection sensitivity using standard pulse-echo measurements was verified and the influence of the stand-off distance predicted from the FE simulation results.

  14. Propagation of ultrasonic Love waves in nonhomogeneous elastic functionally graded materials.

    Science.gov (United States)

    Kiełczyński, P; Szalewski, M; Balcerzak, A; Wieja, K

    2016-02-01

    This paper presents a theoretical study of the propagation behavior of ultrasonic Love waves in nonhomogeneous functionally graded elastic materials, which is a vital problem in the mechanics of solids. The elastic properties (shear modulus) of a semi-infinite elastic half-space vary monotonically with the depth (distance from the surface of the material). The Direct Sturm-Liouville Problem that describes the propagation of Love waves in nonhomogeneous elastic functionally graded materials is formulated and solved by using two methods: i.e., (1) Finite Difference Method, and (2) Haskell-Thompson Transfer Matrix Method. The dispersion curves of phase and group velocity of surface Love waves in inhomogeneous elastic graded materials are evaluated. The integral formula for the group velocity of Love waves in nonhomogeneous elastic graded materials has been established. The effect of elastic non-homogeneities on the dispersion curves of Love waves is discussed. Two Love wave waveguide structures are analyzed: (1) a nonhomogeneous elastic surface layer deposited on a homogeneous elastic substrate, and (2) a semi-infinite nonhomogeneous elastic half-space. Obtained in this work, the phase and group velocity dispersion curves of Love waves propagating in the considered nonhomogeneous elastic waveguides have not previously been reported in the scientific literature. The results of this paper may give a deeper insight into the nature of Love waves propagation in elastic nonhomogeneous functionally graded materials, and can provide theoretical guidance for the design and optimization of Love wave based devices.

  15. Application of Piezoelectric Materials in a Novel Linear Ultrasonic Motor based on Shear-induced Vibration Mode

    Institute of Scientific and Technical Information of China (English)

    CHEN Chao; SHI Yunlai; CHEN Haipeng; ZHAO Chunsheng

    2014-01-01

    A novel linear ultrasonic motor based on d15 effect of piezoelectric materials was presented. The design idea aimed at the direct utilization of the shear-induced vibration modes of piezoelectric material. Firstly, the inherent electromechanical coupling mechanism of piezoelectric material was investigated, and shear vibration modes of a piezoelectric shear block was specially designed. A driving point’s elliptical trajectory induced by shear vibration modes was discussed. Then a dynamic model for the piezoelectric shear stator was established with finite element (FE) method to conduct the parametric optimal design. Finally, a prototype based on d15 converse piezoelectric effect is manufactured, and the modal experiment of piezoelectric stator was conducted with laser doppler vibrometer. The experimental results show that the calculated shear-induced vibration modes can be excited completely, and the new linear ultrasonic motor reaches a speed 118 mm/s at no-load, and maximal thrust 12.8 N.

  16. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong-Jin; Lee, Sun-Kyu, E-mail: skyee@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2015-01-15

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  17. Separation of bacterial spores from flowing water in macro-scale cavities by ultrasonic standing waves

    CERN Document Server

    Lipkens, B; Costolo, M; Stevens, A; Rietman, Edward

    2010-01-01

    The separation of micron-sized bacterial spores (Bacillus cereus) from a steady flow of water through the use of ultrasonic standing waves is demonstrated. An ultrasonic resonator with cross-section of 0.0254 m x 0.0254 m has been designed with a flow inlet and outlet for a water stream that ensures laminar flow conditions into and out of the resonator section of the flow tube. A 0.01905-m diameter PZT-4, nominal 2-MHz transducer is used to generate ultrasonic standing waves in the resonator. The acoustic resonator is 0.0356 m from transducer face to the opposite reflector wall with the acoustic field in a direction orthogonal to the water flow direction. At fixed frequency excitation, spores are concentrated at the stable locations of the acoustic radiation force and trapped in the resonator region. The effect of the transducer voltage and frequency on the efficiency of spore capture in the resonator has been investigated. Successful separation of B. cereus spores from water with typical volume flow rates of...

  18. Faraday Waves-Based Integrated Ultrasonic Micro-Droplet Generator and Applications

    Directory of Open Access Journals (Sweden)

    Chen S. Tsai

    2017-02-01

    Full Text Available An in-depth review on a new ultrasonic micro-droplet generator which utilizes megahertz (MHz Faraday waves excited by silicon-based multiple Fourier horn ultrasonic nozzles (MFHUNs and its potential applications is presented. The new droplet generator has demonstrated capability for producing micro droplets of controllable size and size distribution and desirable throughput at very low electrical drive power. For comparison, the serious deficiencies of current commercial droplet generators (nebulizers and the other ultrasonic droplet generators explored in recent years are first discussed. The architecture, working principle, simulation, and design of the multiple Fourier horns (MFH in resonance aimed at the amplified longitudinal vibration amplitude on the end face of nozzle tip, and the fabrication and characterization of the nozzles are then described in detail. Subsequently, a linear theory on the temporal instability of Faraday waves on a liquid layer resting on the planar end face of the MFHUN and the detailed experimental verifications are presented. The linear theory serves to elucidate the dynamics of droplet ejection from the free liquid surface and predict the vibration amplitude onset threshold for droplet ejection and the droplet diameters. A battery-run pocket-size clogging-free integrated micro droplet generator realized using the MFHUN is then described. The subsequent report on the successful nebulization of a variety of commercial pulmonary medicines against common diseases and on the experimental antidote solutions to cyanide poisoning using the new droplet generator serves to support its imminent application to inhalation drug delivery.

  19. Scattering of ultrasonic shock waves in suspensions of silica nanoparticles.

    Science.gov (United States)

    Baudoin, Michael; Thomas, Jean-Louis; Coulouvrat, François; Chanéac, Corinne

    2011-03-01

    Experiments are carried out to assess, for the first time, the validity of a generalized Burgers' equation, introduced first by Davidson [J. Acoust. Soc. Am. 54, 1331-1342 (1973)] to compute the nonlinear propagation of finite amplitude acoustical waves in suspensions of "rigid" particles. Silica nanoparticles of two sizes (33 and 69 nm) have been synthesized in a water-ethanol mixture and precisely characterized via electron microscopy. An acoustical beam of high amplitude is generated at 1 MHz inside a water tank, leading to the formation of acoustical shock waves through nonlinear steepening. The signal is then measured after propagation in a cylinder containing either a reference solution or suspensions of nanoparticles. In this way, a "nonlinear attenuation" is obtained and compared to the numerical solution of a generalized Burgers' equation adapted to the case of hydrosols. An excellent agreement (corresponding to an error on the particles size estimation of 3 nm) is achieved in the frequency range from 1 to 40 MHz. Both visco-inertial and thermal scattering are significant in the present case, whereas thermal effects can generally be neglected for most hydrosols. This is due to the value of the specific heat ratio of water-ethanol mixture which significantly differs from unity.

  20. Summary of Ultrasonic Motor Drive Control%超声波电动机驱动控制综述

    Institute of Scientific and Technical Information of China (English)

    罗辞勇; 张帆; 卢斌; 肖发福

    2012-01-01

    The development and application of ultrasonic motor rely on its drive control technology, and the performance of drive determines the performance ultrasonic motor to a great extent. All the component parts of driving control and technical key points were introduced. Boost circuits and match circuits were included as the most two important parts. The future development of the drive control technology of ultrasonic motor was prospected.%超声波电动机的发展和应用离不开超声波电动机的驱动控制技术,并且在很大的程度上驱动器的性能决定了超声波电动机的性能.比较全面地阐述了驱动控制的各个组成部分和技术要点,介绍了超声驱动控制技术中升压电路和匹配电路,最后对未来超声波电动机驱动控制技术的发展做了一定的展望.

  1. Local numerical modelling of ultrasonic guided waves in linear and nonlinear media

    Science.gov (United States)

    Packo, Pawel; Radecki, Rafal; Kijanka, Piotr; Staszewski, Wieslaw J.; Uhl, Tadeusz; Leamy, Michael J.

    2017-04-01

    Nonlinear ultrasonic techniques provide improved damage sensitivity compared to linear approaches. The combination of attractive properties of guided waves, such as Lamb waves, with unique features of higher harmonic generation provides great potential for characterization of incipient damage, particularly in plate-like structures. Nonlinear ultrasonic structural health monitoring techniques use interrogation signals at frequencies other than the excitation frequency to detect changes in structural integrity. Signal processing techniques used in non-destructive evaluation are frequently supported by modeling and numerical simulations in order to facilitate problem solution. This paper discusses known and newly-developed local computational strategies for simulating elastic waves, and attempts characterization of their numerical properties in the context of linear and nonlinear media. A hybrid numerical approach combining advantages of the Local Interaction Simulation Approach (LISA) and Cellular Automata for Elastodynamics (CAFE) is proposed for unique treatment of arbitrary strain-stress relations. The iteration equations of the method are derived directly from physical principles employing stress and displacement continuity, leading to an accurate description of the propagation in arbitrarily complex media. Numerical analysis of guided wave propagation, based on the newly developed hybrid approach, is presented and discussed in the paper for linear and nonlinear media. Comparisons to Finite Elements (FE) are also discussed.

  2. Ultrasonic guided wave propagation across waveguide transitions: energy transfer and mode conversion.

    Science.gov (United States)

    Puthillath, Padmakumar; Galan, Jose M; Ren, Baiyang; Lissenden, Cliff J; Rose, Joseph L

    2013-05-01

    Ultrasonic guided wave inspection of structures containing adhesively bonded joints requires an understanding of the interaction of guided waves with geometric and material discontinuities or transitions in the waveguide. Such interactions result in mode conversion with energy being partitioned among the reflected and transmitted modes. The step transition between an aluminum layer and an aluminum-adhesive-aluminum multi-layer waveguide is analyzed as a model structure. Dispersion analysis enables assessment of (i) synchronism through dispersion curve overlap and (ii) wavestructure correlation. Mode-pairs in the multi-layer waveguide are defined relative to a prescribed mode in a single layer as being synchronized and having nearly perfect wavestructure matching. Only a limited number of mode-pairs exist, and each has a unique frequency range. A hybrid model based on semi-analytical finite elements and the normal mode expansion is implemented to assess mode conversion at a step transition in a waveguide. The model results indicate that synchronism and wavestructure matching is associated with energy transfer through the step transition, and that the energy of an incident wave mode in a single layer is transmitted almost entirely to the associated mode-pair, where one exists. This analysis guides the selection of incident modes that convert into transmitted modes and improve adhesive joint inspection with ultrasonic guided waves.

  3. Propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-12-15

    The present study aims to investigate the propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom. The velocities of the guided waves in a 5-mm-thick acrylic plate were measured by using the axial transmission technique. A pure A0 Lamb mode could be successfully launched in the 5-mm-thick acrylic plate through a time reversal process of Lamb waves, consistent with the fact that the time reversal process can automatically compensate for the dispersive nature of Lamb waves. The experimental velocities of the slow guided wave (SGW) and the time-reversed Lamb wave were found to be in reasonable agreement with the theoretical group velocity of the A0 Lamb mode, suggesting that both the SGW and the time-reversed Lamb wave excited in the 5-mm-thick acrylic plate correspond to the A0 Lamb mode. These results suggest that the time reversal process of Lamb waves can be usefully applied to noninvasive characterization of long cortical bones.

  4. Development of an electromagnetic acoustic transducer (EMAT) for the noncontact excitation of guided ultrasonic waves

    Science.gov (United States)

    Fromme, P.

    2015-03-01

    Fatigue damage can develop in aerospace structures at locations of stress concentration, such as fasteners. For the safe operation of the aircraft fatigue cracks need to be detected before reaching a critical length. Guided ultrasonic waves offer an efficient method for the detection and characterization of such defects in large aerospace structures. Noncontact excitation of guided waves was achieved using electromagnetic acoustic transducers (EMAT). The transducer development for the specific excitation of the A0 Lamb wave mode is explained. The radial and angular dependency of the excited guided wave pulses at different frequencies were measured using a noncontact laser interferometer. Based on the induced eddy currents in the plate a theoretical model was developed and reasonably good agreement with the measured transducer performance was achieved. The developed transducers were employed for defect detection in aluminum components using fully noncontact guided wave measurements. Excitation of the A0 Lamb wave mode was achieved using the developed EMAT transducer and the guided wave propagation and scattering was measured using a noncontact laser interferometer. These results provide the basis for the defect characterization in aerospace structures using noncontact guided wave sensors.

  5. Ultrasonic nonlinear guided wave inspection of microscopic damage in a composite structure

    Science.gov (United States)

    Zhang, Li; Borigo, Cody; Owens, Steven; Lissenden, Clifford; Rose, Joseph; Hakoda, Chris

    2017-02-01

    Sudden structural failure is a severe safety threat to many types of military and industrial composite structures. Because sudden structural failure may occur in a composite structure shortly after macroscale damage initiates, reliable early diagnosis of microdamage formation in the composite structure is critical to ensure safe operation and to reduce maintenance costs. Ultrasonic guided waves have been widely used for long-range defect detection in various structures. When guided waves are generated under certain excitation conditions, in addition to the traditional linear wave mode (known as the fundamental harmonic wave mode), a number of nonlinear higher-order harmonic wave modes are also be generated. Research shows that the nonlinear parameters of a higher-order harmonic wave mode could have excellent sensitivity to microstructural changes in a material. In this work, we successfully employed a nonlinear guided wave structural health monitoring (SHM) method to detect microscopic impact damage in a 32-layer carbon/epoxy fiber-reinforced composite plate. Our effort has demonstrated that, utilizing appropriate transducer design, equipment, excitation signals, and signal processing techniques, nonlinear guided wave parameter measurements can be reliably used to monitor microdamage initiation and growth in composite structures.

  6. Effects of ultrasonic waves on the interfacial forces between oil and water.

    Science.gov (United States)

    Hamida, Tarek; Babadagli, Tayfun

    2008-04-01

    The effect of ultrasound on flow through a capillary using the pendant drop method was investigated. Water was injected into a 0.1 mm Hastelloy C-276 capillary tube submersed into several mineral oils with different viscosity, and kerosene. The average drop rate per minute was measured at several ultrasonic intensities. We observed that there exists a peak drop rate at a characteristic intensity, which strongly depends on oil viscosity and the interfacial tension between water and the oil. The semi-quantitative results reveal that the remarkable change in the interfacial forces between oil and water could be the explanation to the enhancement of oil recovery when the ultrasonic waves are applied.

  7. Sensitivity of contact-free fiber Bragg grating sensor to ultrasonic Lamb wave

    Science.gov (United States)

    Wee, Junghyun; Hackney, Drew; Peters, Kara; Wells, Brian; Bradford, Philip

    2016-04-01

    Networks of fiber Bragg grating (FBG) sensors can serve as structural health monitoring (SHM) systems for large-scale structures based on the collection of ultrasonic waves. The demodulation of structural Lamb waves requires a high signal-to-noise ratio because Lamb waves have a low amplitude. This paper investigates the signal transfer between Lamb waves propagating in an aluminum plate collected by an optical fiber containing a FBG. The fiber is bonded to the plate at locations away from the FBG. The Lamb waves are converted into longitudinal and flexural traveling waves propagating along the optical fiber, which are then transmitted to the Bragg grating. The signal wave amplitude is measured for different distances between the bond location and the Bragg grating. Bonding the optical fiber away from the FBG location and closer to the signal source produces a significant increase in signal amplitude, here measured to be 5.1 times that of bonding the Bragg grating itself. The arrival time of the different measured wave coupling paths are also calculated theoretically, verifying the source of the measured signals. The effect of the bond length to Lamb wavelength ratio is investigated, showing a peak response as the bond length is reduced compared to the wavelength. This study demonstrates that coupling Lamb waves into guided traveling waves in an optical fiber away from the FBG increases the signal-to-noise ratio of Lamb wave detection, as compared to direct transfer of the Lamb wave to the optical fiber at the location of the FBG.

  8. Generation of Laser Light via Ultrasonic Four-wave Mixing

    Institute of Scientific and Technical Information of China (English)

    OU Fa; WU Fugen; HE Minggao

    2001-01-01

    On the basis of the interaction between phonons in ionic crystals with anharmonic lattice vibration, we present a laser model on acoustic nondegenerate four-wave mixing. Two beams of highfrequency ultrasound, incident on the acoustic cavity fulfilled with the medium of ionic crystal, play the role of pumping and one of the two side-band modes of the pumping frequency as an acoustic signal mode has a strong interaction with the optical cavity mode, the coupling-out of which wiIl be the light (far-infrared) output of a laser. The problem is treated with quantum-mechanics. The theory shows that there is the threshold phenomenon as usual lasers and a so called "phase-matching" condition is derived, which should be satisfied for stability of the system.

  9. Design of ultrasonic probe and evaluation of ultrasonic waves on E.coli in Sour Cherry Juice

    Directory of Open Access Journals (Sweden)

    B Hosseinzadeh Samani

    2015-09-01

    Full Text Available Introduction: The common method used for juice pasteurization is the thermal method since thermal methods contribute highly to inactivating microbes. However, applying high temperatures would lead to inefficient effects on nutrition and food value. Such effects may include vitamin loss, nutritional flavor loss, non-enzyme browning, and protein reshaping (Kuldiloke, 2002. In order to decrease the adverse effects of the thermal pasteurization method, other methods capable of inactivation of microorganisms can be applied. In doing so, non-thermal methods including pasteurization using high hydrostatic pressure processing (HPP, electrical fields, and ultrasound waves are of interest (Chen and Tseng, 1996. The reason for diminishing microbial count in the presence of ultrasonic waves could be due to the burst of very tiny bubbles developed by ultrasounds which expand quickly and burst in a short time. Due to this burst, special temperature and pressure conditions are developed which could initiate or intensify several physical and/or chemical reactions. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. Materials and methods: In order to supply uniform ultrasonic waves, a 1000 W electric generator (Model MPI, Switzerland working at 20±1 kHz frequency was used. The aim of this study is to evaluate the non-thermal ultrasonic method and its effective factors on the E.coli bacteria of sour cherry. For this purpose, a certain amount of sour cherry fruit was purchased from local markets. First, the fruits were washed, cleaned and cored. The prepared fruits were then dewatered using an electric juicer. In order to separate pulp suspensions and tissue components, the extracted juice was poured into a centrifuge with the speed of 6000 rpm for 20 min. For complete separation of the remaining suspended particles, the transparent portion of the extract was passed through a

  10. A Low Mass Translation Mechanism for Planetary FTIR Spectrometry using an Ultrasonic Piezo Linear Motor

    Science.gov (United States)

    Heverly, Matthew; Dougherty, Sean; Toon, Geoffrey; Soto, Alejandro; Blavier, Jean-Francois

    2004-01-01

    One of the key components of a Fourier Transform Infrared Spectrometer (FTIR) is the linear translation stage used to vary the optical path length between the two arms of the interferometer. This translation mechanism must produce extremely constant velocity motion across its entire range of travel to allow the instrument to attain high signal-to-noise ratio and spectral resolving power. A new spectrometer is being developed at the Jet Propulsion Laboratory under NASA s Planetary Instrument Definition and Development Program (PIDDP). The goal of this project is to build upon existing spaceborne FTIR spectrometer technology to produce a new instrument prototype that has drastically superior spectral resolution and substantially lower mass, making it feasible for planetary exploration. In order to achieve these goals, Alliance Spacesystems, Inc. (ASI) has developed a linear translation mechanism using a novel ultrasonic piezo linear motor in conjunction with a fully kinematic, fault tolerant linear rail system. The piezo motor provides extremely smooth motion, is inherently redundant, and is capable of producing unlimited travel. The kinematic rail uses spherical Vespel(R). rollers and bushings, which eliminates the need for wet lubrication, while providing a fault tolerant platform for smooth linear motion that will not bind under misalignment or structural deformation. This system can produce velocities from 10 - 100 mm/s with less than 1% velocity error over the entire 100-mm length of travel for a total mechanism mass of less than 850 grams. This system has performed over half a million strokes under vacuum without excessive wear or degradation in performance. This paper covers the design, development, and testing of this linear translation mechanism as part of the Planetary Atmosphere Occultation Spectrometer (PAOS) instrument prototype development program.

  11. Integrating optopiezoelectric actuators and a two-mode excited linear ultrasonic motor for microfluidics

    Science.gov (United States)

    Chen, Tsun-Hsu; Wang, Hsin-Hu; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    In comparison to more developed optical method for microparticle manipulation like optical tweezers, an optopiezoelectric actuating system could provide force output that is several orders higher. Taking advantages of photoconductive materials, the concept of integrating a virtual electrode in a distributed opto-piezoelectric actuators was developed for real-time in-situ spatial tailoring for vast varieties of applications in biochips, smart structures, etc. In this study, photoconductive material titanium oxide phthalocyanine (TiOPc) was used as the active ingredient to enable the virtual electrode in an opto-piezoelectric material based distributed actuator. By illuminating light of proper wavelength and enough intensity onto TiOPc photoconductive material, the effective impedance of the illuminated portion of TiOPc could drop significantly. The contributions of using additives in the TiOPc photoconductive electrode to adjust the electrical properties was investigated for optimization. Further, the two-mode excited linear ultrasonic motor was also studied and the feasibility to integrate the TiOPc photoconductive electrode was discussed. The flexibility provided by this newly developed system could potential deliver versatile performance in biochip applications.

  12. Frequency domain laser ultrasonics: Optical transduction of acoustic waves and nanomechanical devices

    Science.gov (United States)

    Bramhavar, Suraj

    The concept of optical excitation and detection of nanoscale mechanical motion has led to a variety of tools for non-destructive materials characterization and remote sensing. These techniques, commonly referred to as laser ultrasonics, offer the benefit of high-bandwidth, highly localized measurements, and also allow for the ability to investigate nanoscale devices. The impact of laser ultrasonic systems has been felt in industries ranging from semiconductor metrology to biological and chemical sensing. In this thesis, we develop a variety of techniques utilizing a frequency domain laser ultrasonic approach, where amplitude modulated continuous wave laser light is used instead of traditional pulsed laser sources, and we apply these systems in free-space, optical fiber based, and integrated on-chip configurations. In doing so, we demonstrate the ability to efficiently transduce various types of mechanical motion including surface and bulk acoustic waves, guided acoustic waves, and resonant motion from nanomechanical systems (NEMS). First, we develop a superheterodyne free-space ultrasonic inspection system in an effort to characterize surface acoustic wave dispersion in thin-film material systems. We utilize a similar system to study negative refraction and focusing behavior of guided elastic waves in a thin metal plate, providing a novel approach for the study of negative index physics. Furthermore, we develop a near-field optical technique using optical fibers to simultaneously transduce the motion of 70 NEMS resonators using a single channel. This multiplexed approach serves as a crucial step in moving NEMS technology out of the research laboratory. Finally, we go on to study opto-mechanical interactions between optical whispering gallery mode (WGM) resonators and integrated NEMS devices on the same chip, using the enhanced interactions to study optical forces acting on the nanoscale mechanical devices. This integrated system provides a very efficient mechanical

  13. Ultrasonic Waveguide Sensor Using a Leaky Lamb Wave for Under-Sodium Viewing

    Science.gov (United States)

    Joo, Young-Sang; Lee, Jae-Han

    2010-02-01

    A plate-type ultrasonic waveguide sensor using a leaky Lamb wave has been developed for the under-sodium viewing of a reactor core and in-vessel structures of a sodium-cooled fast reactor (SFR). An A0 Lamb wave mode is utilized in the waveguide sensor for the single mode generation and the effective radiation capability in a fluid. A radiation beam steering technique is presented which is achieved by the frequency tuning of the excitation pulse in the frequency range of the A0 Lamb wave mode which the group velocity is not dispersive and the phase velocity is dispersive. The long distance propagation ability and C-scan imaging performance have been demonstrated successfully by experimental feasibility tests of the waveguide sensor.

  14. New ultrasonic Bleustein-Gulyaev wave method for measuring the viscosity of liquids at high pressure

    Science.gov (United States)

    Kiełczyński, P.; Szalewski, M.; Siegoczyński, R. M.; Rostocki, A. J.

    2008-02-01

    In this paper, a new method for measuring the viscosity of liquids at high pressure is presented. To this end the authors have applied an ultrasonic method using the Bleustein-Gulyaev (BG) surface acoustic wave. By applying the perturbation method, we can prove that the change in the complex propagation constant of the BG wave produced by the layer of liquid loading the waveguide surface is proportional to the shear mechanical impedance of the liquid. In the article, a measuring setup employing the BG wave for the purpose of measuring the viscosity of liquids at high pressure (up to 1GPa) is presented. The results of high-pressure viscosity measurements of triolein and castor oil are also presented. In this paper the model of a Newtonian liquid was applied. Using this new method it is also possible to measure the viscosity of liquids during the phase transition and during the decompression process (hysteresis of the dependence of viscosity on pressure).

  15. Effect of stress on energy flux deviation of ultrasonic waves in GR/EP composites

    Science.gov (United States)

    Prosser, William H.; Kriz, R. D.; Fitting, Dale W.

    1990-01-01

    Ultrasonic waves suffer energy flux deviation in graphite/epoxy because of the large anisotropy. The angle of deviation is a function of the elastic coefficients. For nonlinear solids, these coefficients and thus the angle of deviation is a function of stress. Acoustoelastic theory was used to model the effect of stress on flux deviation for unidirectional T300/5208 using previously measured elastic coefficients. Computations were made for uniaxial stress along the x3 axis (fiber axis) and the x1 for waves propagating in the x1x3 plane. These results predict a shift as large as three degrees for the quasi-transverse wave. The shift in energy flux offers a new nondestructive technique of evaluating stress in composites.

  16. On the processing of highly nonlinear solitary waves and guided ultrasonic waves for structural health monitoring and nondestructive evaluation

    Science.gov (United States)

    Bagheri, Abdollah

    The in-situ measurement of thermal stress in civil and mechanical structures may prevent structural anomalies such as unexpected buckling. In the first half of the dissertation, we present a study where highly nonlinear solitary waves (HNSWs) were utilized to measure axial stress in slender beams. HNSWs are compact non-dispersive waves that can form and travel in nonlinear systems such as one-dimensional chains of particles. The effect of the axial stress acting in a beam on the propagation of HNSWs was studied. We found that certain features of the solitary waves enable the measurement of the stress. In general, most guided ultrasonic waves (GUWs)-based health monitoring approaches for structural waveguides are based on the comparison of testing data to baseline data. In the second half of the dissertation, we present a study where some baseline-free signal processing algorithms were presented and applied to numerical and experimental data for the structural health monitoring (SHM) of underwater or dry structures. The algorithms are based on one or more of the following: continuous wavelet transform, empirical mode decomposition, Hilbert transform, competitive optimization algorithm, probabilistic methods. Moreover, experimental data were also processed to extract some features from the time, frequency, and joint time-frequency domains. These features were then fed to a supervised learning algorithm based on artificial neural networks to classify the types of defect. The methods were validated using the numerical model of a plate and a pipe, and the experimental study of a plate in water. In experiment, the propagation of ultrasonic waves was induced by means of laser pulses or transducer and detected with an array of immersion transducers. The results demonstrated that the algorithms are effective, robust against noise, and able to localize and classify the damage.

  17. 基于FPGA的数字PI超声波电动机速度控制系统%Digital PI Speed Control System of Ultrasonic Motor Based on FPGA

    Institute of Scientific and Technical Information of China (English)

    陈斌; 冯浩; 赵浩

    2012-01-01

    针对超声波电动机速度蠕动,提出一种基于FPGA的数字PI的速度控制方案.该方案对超声波电动机输出的光电编码器方波信号进行高频插值细分,作为速度的反馈信号,通过PI运算,将其结果进行D/A转换,控制直流电压的输出,并把此直流电压作为超声波电动机驱动器的调速控制电压,构成超声波电动机速度闭环系统,从而有效解决了超声波电动机转速蠕动的问题.%A scheme of digital PI speed control based on FPGA for ultrasonic motor was proposed to solve the problem of its speed creep. The square-wave signal of photoelectric decoder was operated by high-frequency interpolatory subdivision as the speed feedback signal. The results was transformed by D/A converter through PI operation. The output DC voltage was controlled, which was considered as the speed setting voltage of ultrasonic motor drive. The closed-loop speed control of ultrasonic motor was achieved and the problem of its speed creep was solved effectively.

  18. Application of ultrasonic guided waves to the characterization of texture in metal sheets of cubic and hexagonal crystallites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan.

    1990-10-08

    Ultrasonic techniques have recently been applied to the texture characterization in polycrystalline aggregates of hexagonal crystals. The basis of this application lies in the relations between the elastic constants {bar C}{sub ij} of the aggregates, which can be inferred from ultrasonic wave velocity measurements, and the orientation distribution coefficients. This communication present such relations for aggregates which possess orthotopic material symmetry and hexagonal crystal symmetry for Voigt, Reuss, and Hill averaging methods in a unified and concise representation.

  19. Generation mechanism of nonlinear ultrasonic Lamb waves in thin plates with randomly distributed micro-cracks.

    Science.gov (United States)

    Zhao, Youxuan; Li, Feilong; Cao, Peng; Liu, Yaolu; Zhang, Jianyu; Fu, Shaoyun; Zhang, Jun; Hu, Ning

    2017-08-01

    Since the identification of micro-cracks in engineering materials is very valuable in understanding the initial and slight changes in mechanical properties of materials under complex working environments, numerical simulations on the propagation of the low frequency S0 Lamb wave in thin plates with randomly distributed micro-cracks were performed to study the behavior of nonlinear Lamb waves. The results showed that while the influence of the randomly distributed micro-cracks on the phase velocity of the low frequency S0 fundamental waves could be neglected, significant ultrasonic nonlinear effects caused by the randomly distributed micro-cracks was discovered, which mainly presented as a second harmonic generation. By using a Monte Carlo simulation method, we found that the acoustic nonlinear parameter increased linearly with the micro-crack density and the size of micro-crack zone, and it was also related to the excitation frequency and friction coefficient of the micro-crack surfaces. In addition, it was found that the nonlinear effect of waves reflected by the micro-cracks was more noticeable than that of the transmitted waves. This study theoretically reveals that the low frequency S0 mode of Lamb waves can be used as the fundamental waves to quantitatively identify micro-cracks in thin plates. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Numerical comparison of patch and sandwich piezoelectric transducers for transmitting ultrasonic waves

    Science.gov (United States)

    Loveday, Philip W.

    2006-03-01

    Guided wave ultrasonic inspection is becoming an important method of non-destructive testing for long, slender structures such as pipes and rails. Often it is desirable to use transducers that can strongly excite a specific mode of wave propagation in the waveguide. Piezoelectric patch transducers are frequently employed, by researchers, for exciting waves in beam like structures. Sonar systems frequently make use of resonant transducers, such as sandwich transducers, for acoustic wave generation and this principle has been used to excite waves in a rail. This paper compares the two transduction approaches, for launching bending waves in rectangular waveguides, with numerical modeling. The numerical modeling combined a waveguide finite element model, of the waveguide, with conventional three-dimensional piezoelectric finite element models of the transducers. The waveguide finite elements were formulated using a complex exponential to describe the wave propagation along the structure and conventional finite element interpolation over the area of the element. Consequently, only a two-dimensional finite element mesh covering the cross-section of the waveguide is required. The harmonic forced response of the waveguide was used to compute a complex dynamic stiffness matrix which represented the waveguide in the transducer model. The effects of geometrical parameters of patch and sandwich transducers were considered before the comparison was made. It appears that piezoelectric patch transducers offer advantages at low frequencies while sandwich transducers are superior at high frequencies, where resonance can be exploited, at the cost of more complex design.

  1. High precision ultrasonic guided wave technique for inspection of power transmission line

    Science.gov (United States)

    Cheng, Jun; Qiu, Jinhao; Ji, Hongli; Wang, Enrong; Takagi, Toshiyuki; Uchimoto, Tetsuya

    2017-01-01

    Due to the merits of high inspection speed and long detecting distance, Ultrasonic Guided Wave(UGW) method has been commonly applied to the on-line maintenance of power transmission line. However, the guided wave propagation in this structure is very complicated, leading to the unfavorable defect localization accuracy. Aiming at this situation, a high precision UGW technique for inspection of local surface defect in power transmission line is proposed. The technique is realized by adopting a novel segmental piezoelectric ring transducer and transducer mounting scheme, combining with the comprehensive characterization of wave propagation and circumferential defect positioning with multiple piezoelectric elements. Firstly, the propagation path of guided waves in the multi-wires of transmission line under the proposed technique condition is investigated experimentally. Next, the wave velocities are calculated by dispersion curves and experiment test respectively, and from comparing of the two results, the guided wave mode propagated in transmission line is confirmed to be F(1,1) mode. Finally, the axial and circumferential positioning of local defective wires in transmission line are both achieved, by using multiple piezoelectric elements to surround the stands and send elastic waves into every single wire. The proposed research can play a role of guiding the development of highly effective UGW method and detecting system for multi-wire transmission line.

  2. Ultrasonic Beam Radiation of an A0 Leaky Lamb Wave in a Plate Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jin Ho; Joo, Young Sang; Kim, Jong Bum [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Rhee, Hui Nam [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    As the sodium coolant of a sodium-cooled fast reactor (SFR) is opaque to light, a conventional visual inspection cannot be used for carrying out an in-service inspection of the internal structures under a sodium level. An ultrasonic wave should be applied for an under-sodium viewing of the internal structures in a reactor vessel. Immersion sensors and waveguide sensors have been applied to the under-sodium visualization. The immersion sensor has a precise imaging capability, but may have high temperature restrictions and an uncertain life. The waveguide sensor has the advantages of a long lifetime and stable application. Recently, a new plate waveguide sensor has been developed for the versatile applications in the under-sodium viewing application. In the plate waveguide sensor, the A0 leaky Lamb wave is utilized for the long distance propagation and the effective radiation capability in a fluid. And a new technique is presented which is capable of steering an ultrasonic beam of a waveguide sensor without a mechanical movement of the sensor assembly. In this paper, the experimental study of the radiation beam profile of the A0 leaky Lamb wave in a plate waveguide sensor is carried out

  3. Parametric Study of Defect Detection in Pipes with Bend Using Guided Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Jack Tan Jin

    2016-01-01

    Full Text Available The propagation behaviour of guided ultrasonic waves in a steel pipe with welded bend is studied by finite element simulation. The effectiveness of the longitudinal L(0,2 and torsional T(0,1 guided waves in detecting circumferential cut near the weld is investigated. In order to identify the presence of the defect, the reflection strength due to the cut is studied. The geometry of the weld is constructed based on common V-bevel butt joints and the anisotropy of the 316L stainless steel weld is included to correctly predict the scattering of ultrasonic waves. The finite element model is built to allow high accuracy. Detection of small circumferential cut (up to 60° circumferential extent can be achieved with longitudinal L(0,2 mode. Detection of moderate to large circumferential cut can be achieved by torsional T(0,1 or longitudinal L(0,2 modes, with T(0,1 mode preferred due to its less mode conversion to higher order modes.

  4. [Investigation of ultrasonic wave interactions with fluid-saturated porous rocks]. [Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Adler, L.

    1992-07-01

    During the last two years we have continued our investigation of ultrasonic wave propagation in fluid-filled porous materials. First, we studied the feasibility of using different surface modes to characterize both synthetic and natural rocks. We introduced a novel experimental technique based on the direct generation of surface waves by edge excitation. We used two low-frequency (100--500 kHz) shear transducers in pitch-catch mode to launch and receive the ultrasonic surface wave. The contact transducers were coupled to the opposite edges of the porous specimens with normal polarization relative to the surface. The same technique was successfully used to generate Rayleigh-type surface modes on the free surface of both dry and water-saturated specimens, as well as Stoneley-type interface modes on the fluid-loaded surfaces of immersed samples. Our main achievement in this area is the realization that, due to surface tension, practically closed-pore boundary conditions can prevail on the free surface of a water-saturated rock for completely open pores. As a result, the velocity of the true surface mode might be much lower than the Rayleigh velocity of the dry skeleton.

  5. A Shear-Mode Ultrasonic Motor Using Potassium Sodium Niobate-Based Ceramics with High Mechanical Quality Factor

    Science.gov (United States)

    Li, Enzhu; Kakemoto, Hirofumi; Hoshina, Takuya; Tsurumi, Takaaki

    2008-09-01

    (K,Na)NbO3-LiNbO3-CuO lead-free piezoelectric ceramics that show a high mechanical quality factor Qm were synthesized and used as a drive element of an ultrasonic motor. The Qm of the (K,Na)NbO3 ceramic could be enhanced by chemical modification using Li and Cu as well as microstructure control to obtain ceramics with fine grains. The grain size dependence of the Qm was consistent with a model based on the formation of internal bias field to stabilize the domain structure. A shear mode was used to drive the ultrasonic motor because the piezoelectric d31 and d33 constants of the ceramics were not sufficient for the motor applications. A shear-mode motor driven with four piezoelectric ceramic plates was developed using the lead-free ceramics with a high Qm of 1400, a high d15 of 207 pC/N, and a high k15 of 0.72. The highest revolution speed of 486 rpm was achieved at 34.5 kHz with the input voltage of approximately 180 Vp-p (peak to peak).

  6. Ultrasonic detection of embedded and surface defects in thin plates using Lamb waves

    Science.gov (United States)

    Conry, M. J.; Crane, L. J.; Gilchrist, Michael

    2003-03-01

    Non-destructive Testing and Evaluation (NDT&E) is critical in the safety assurance of modern engineering structures, particularly when using high performance materials. Frequently, such materials are subject to mechanisms of damage uncommon in conventional structures. Additionally, many high performance alloys such as advanced aerospace aluminiums are more susceptible to fatigue failure than more traditional metals. In all such cases, it is essential to have good knowledge of the defects present in a component in order to assess its soundness. One of the most common and verstaile techniques used in NDT&E is ultrasonic testing, where the integrity of a component is characterized using acoustic waves.

  7. Fatigue damage evaluation of austenitic stainless steel using nonlinear ultrasonic waves in low cycle regime

    Science.gov (United States)

    Zhang, Jianfeng; Xuan, Fu-Zhen

    2014-05-01

    The interrupted low cycle fatigue test of austenitic stainless steel was conducted and the dislocation structure and fatigue damage was evaluated subsequently by using both transmission electron microscope and nonlinear ultrasonic wave techniques. A "mountain shape" correlation between the nonlinear acoustic parameter and the fatigue life fraction was achieved. This was ascribed to the generation and evolution of planar dislocation structure and nonplanar dislocation structure such as veins, walls, and cells. The "mountain shape" correlation was interpreted successfully by the combined contribution of dislocation monopole and dipole with an internal-stress dependent term of acoustic nonlinearity.

  8. Elastic friction drive of surface acoustic wave motor.

    Science.gov (United States)

    Kurosawa, Minoru Kuribayashi; Itoh, Hidenori; Asai, Katsuhiko

    2003-06-01

    Importance of elastic deformation control to obtain large output force with a surface acoustic wave (SAW) motor is discussed in this paper. By adding pre-load to slider, stator and slider surfaces are deformed in a few tens nanometer. Appropriate deformation in normal direction against normal vibration displacement amplitude of SAW existed. By moderate deformation, the output force of the SAW motor was enlarged up to about 10 N and no-load speed was 0.7 m/s. To produce this performance, the transducer weight and slider size were only 4.2 g and 4 x 4 mm(2).By traveling wave propagation, surface particles of the SAW device move in elliptical motion. Due to the amplitude of the elliptical motion is 10 or 20 nm order, the contact condition of the slider is very critical. To control the contact condition, namely, the elastic deformation of the slider and stator surface in nanometer order, a lot of projections were fabricated on the slider surface. The projection diameter was 20 micro m. In static condition, the elastic deformation and stress were evaluated with the FEM analysis. From this calculation and the simulation result, it is consider that the wave crest is distorted, hence the elasticity has influence on the friction drive condition. Elastic deformation of the stator surface beneath the projection from the initial position were evaluated. In 4 x 4 mm(2) square area, the sliders had from 1089 to 23,409 projections. Depression was independent to the contact pressure. However, the output force depended on the depression although the projection density were different. From the view point of the output power of the motor, the proper depression was independent to the projection density. Around 25 nm depression, the output force and output power were maximized. This depression value was almost same as the vibration displacement amplitude of the stator transducer.

  9. Transport parameters for pulsed ultrasonic waves propagating in an aluminum foam

    Science.gov (United States)

    Tourin, Arnaud; Derode, Arnaud; Mamou, Victor; Fink, Mathias; Page, John; Cowan, Michael L.

    2002-11-01

    Aluminum foams have now been studied for many years in large part because of their applications as light-weight elastic materials (e.g., car bumpers, aerospace engineering applications). The pore size and the spatial distribution of the pores govern the mechanical behavior of the foam and can vary enormously depending on the method of manufacturing. Thus, new methods for the nondestructive characterization of these materials are needed. We present here a set of experimental ultrasonic methods in a range of frequencies where the ultrasonic waves are multiply scattered in the medium. In this regime, the propagation is described by ultrasonic transport parameters which are related to the microstructure of the foam. The diffusion coefficient and the absorption mean free path have been determined in pulse transmission experiments by fitting the solution of the diffusion equation to the average intensity, the so-called time of flight distribution. To more fully characterize the medium, the transport mean path and the diffusion coefficient have been measured in backscattering experiments using the static and dynamic coherent backscattering effects. For both methods, the properties of the sample interfaces have been taken into account.

  10. Errors and uncertainties in the measurement of ultrasonic wave attenuation and phase velocity.

    Science.gov (United States)

    Kalashnikov, Alexander N; Challis, Richard E

    2005-10-01

    This paper presents an analysis of the error generation mechanisms that affect the accuracy of measurements of ultrasonic wave attenuation coefficient and phase velocity as functions of frequency. In the first stage of the analysis we show that electronic system noise, expressed in the frequency domain, maps into errors in the attenuation and the phase velocity spectra in a highly nonlinear way; the condition for minimum error is when the total measured attenuation is around 1 Neper. The maximum measurable total attenuation has a practical limit of around 6 Nepers and the minimum measurable value is around 0.1 Neper. In the second part of the paper we consider electronic noise as the primary source of measurement error; errors in attenuation result from additive noise whereas errors in phase velocity result from both additive noise and system timing jitter. Quantization noise can be neglected if the amplitude of the additive noise is comparable with the quantization step, and coherent averaging is employed. Experimental results are presented which confirm the relationship between electronic noise and measurement errors. The analytical technique is applicable to the design of ultrasonic spectrometers, formal assessment of the accuracy of ultrasonic measurements, and the optimization of signal processing procedures to achieve a specified accuracy.

  11. Design and Implementation of an Electronic Front-End Based on Square Wave Excitation for Ultrasonic Torsional Guided Wave Viscosity Sensor.

    Science.gov (United States)

    Rabani, Amir

    2016-10-12

    The market for process instruments generally requires low cost devices that are robust, small in size, portable, and usable in-plant. Ultrasonic torsional guided wave sensors have received much attention by researchers for measurement of viscosity and/or density of fluids in recent years. The supporting electronic systems for these sensors providing many different settings of sine-wave signals are bulky and expensive. In contrast, a system based on bursts of square waves instead of sine waves would have a considerable advantage in that respect and could be built using simple integrated circuits at a cost that is orders of magnitude lower than for a windowed sine wave device. This paper explores the possibility of using square wave bursts as the driving signal source for the ultrasonic torsional guided wave viscosity sensor. A simple design of a compact and fully automatic analogue square wave front-end for the sensor is also proposed. The successful operation of the system is demonstrated by using the sensor for measuring the viscosity in a representative fluid. This work provides the basis for design and manufacture of low cost compact standalone ultrasonic guided wave sensors and enlightens the possibility of using coded excitation techniques utilising square wave sequences in such applications.

  12. Design and Implementation of an Electronic Front-End Based on Square Wave Excitation for Ultrasonic Torsional Guided Wave Viscosity Sensor

    Directory of Open Access Journals (Sweden)

    Amir Rabani

    2016-10-01

    Full Text Available The market for process instruments generally requires low cost devices that are robust, small in size, portable, and usable in-plant. Ultrasonic torsional guided wave sensors have received much attention by researchers for measurement of viscosity and/or density of fluids in recent years. The supporting electronic systems for these sensors providing many different settings of sine-wave signals are bulky and expensive. In contrast, a system based on bursts of square waves instead of sine waves would have a considerable advantage in that respect and could be built using simple integrated circuits at a cost that is orders of magnitude lower than for a windowed sine wave device. This paper explores the possibility of using square wave bursts as the driving signal source for the ultrasonic torsional guided wave viscosity sensor. A simple design of a compact and fully automatic analogue square wave front-end for the sensor is also proposed. The successful operation of the system is demonstrated by using the sensor for measuring the viscosity in a representative fluid. This work provides the basis for design and manufacture of low cost compact standalone ultrasonic guided wave sensors and enlightens the possibility of using coded excitation techniques utilising square wave sequences in such applications.

  13. New Heuristics for Interfacing Human Motor System using Brain Waves

    Directory of Open Access Journals (Sweden)

    Mohammed El-Dosuky

    2012-09-01

    Full Text Available There are many new forms of interfacing human users to machines. We persevere here electric-mechanical form of interaction between human and machine. The emergence of brain-computer interface allows mind-to-movement systems. The story of the Pied Piper inspired us to devise some new heuristics for interfacing human motor system using brain waves, by combining head helmet and LumbarMotionMonitor. For the simulation we use java GridGain. Brain responses of classified subjects during training indicates that Probe can be the best stimulus to rely on in distinguishing between knowledgeable and not knowledgeable

  14. Influence of local mechanical properties of high strength steel from large size forged ingot on ultrasonic wave velocities

    Science.gov (United States)

    Dupont-Marillia, Frederic; Jahazi, Mohamad; Lafreniere, Serge; Belanger, Pierre

    2017-02-01

    In the metallurgical industry, ultrasonic inspection is routinely used for the detection of defects. For the non-destructive inspection of small high strength steel parts, the material can be considered isotropic. However, when the size of the parts under inspection is large, the isotropic material hypothesis does not necessarily hold. The aim of this study is to investigate the effect of the variation in mechanical properties such as grain size, Young's modulus, Poissons ratio, chemical composition on longitudinal and transversal ultrasonic wave velocities. A 2 cm thick slice cut from a 40-ton bainitic steel ingot that was forged and heat treated was divided into 875 parallelepiped samples of 2x4x7 cm3. A metallurgical study has been performed to identify the phase and measure the grain size. Ultrasonic velocity measurements at 2.25 MHz for longitudinal and transversal waves were performed. The original location of the parallelepiped samples in the large forged ingot, and the measured velocities were used to produce an ultrasonic velocity map. Using a local isotropy assumption as well as the local density of the parallelepiped samples calculated from the chemical composition of the ingot provided by a previously published study, Youngs modulus and Poissons ratio were calculated from the longitudinal and transversal wave velocities. Micro-tensile test was used to validate Youngs modulus obtained by the ultrasonic wave velocity and an excellent agreement was observed.

  15. WFR-2D: an analytical model for PWAS-generated 2D ultrasonic guided wave propagation

    Science.gov (United States)

    Shen, Yanfeng; Giurgiutiu, Victor

    2014-03-01

    This paper presents WaveFormRevealer 2-D (WFR-2D), an analytical predictive tool for the simulation of 2-D ultrasonic guided wave propagation and interaction with damage. The design of structural health monitoring (SHM) systems and self-aware smart structures requires the exploration of a wide range of parameters to achieve best detection and quantification of certain types of damage. Such need for parameter exploration on sensor dimension, location, guided wave characteristics (mode type, frequency, wavelength, etc.) can be best satisfied with analytical models which are fast and efficient. The analytical model was constructed based on the exact 2-D Lamb wave solution using Bessel and Hankel functions. Damage effects were inserted in the model by considering the damage as a secondary wave source with complex-valued directivity scattering coefficients containing both amplitude and phase information from wave-damage interaction. The analytical procedure was coded with MATLAB, and a predictive simulation tool called WaveFormRevealer 2-D was developed. The wave-damage interaction coefficients (WDICs) were extracted from harmonic analysis of local finite element model (FEM) with artificial non-reflective boundaries (NRB). The WFR-2D analytical simulation results were compared and verified with full scale multiphysics finite element models and experiments with scanning laser vibrometer. First, Lamb wave propagation in a pristine aluminum plate was simulated with WFR-2D, compared with finite element results, and verified by experiments. Then, an inhomogeneity was machined into the plate to represent damage. Analytical modeling was carried out, and verified by finite element simulation and experiments. This paper finishes with conclusions and suggestions for future work.

  16. Non-contact ultrasonic technique for Lamb wave characterization in composite plates.

    Science.gov (United States)

    Harb, M S; Yuan, F G

    2016-01-01

    A fully non-contact single-sided air-coupled and laser ultrasonic non-destructive system based on the generation and detection of Lamb waves is implemented for the characterization of A0 Lamb wave mode dispersion in a composite plate. An air-coupled transducer (ACT) radiates acoustic pressure on the surface of the composite and generates Lamb waves within the structure. The out-of-plane velocity of the propagating wave is measured using a laser Doppler vibrometer (LDV). In this study, the non-contact automated system focuses on measuring A0 mode frequency-wavenumber, phase velocity dispersion curves using Snell's law and group velocity dispersion curves using Morlet wavelet transform (MWT) based on time-of-flight along different wave propagation directions. It is theoretically demonstrated that Snell's law represents a direct link between the phase velocity of the generated Lamb wave mode and the coincidence angle of the ACT. Using Snell's law and MWT, the former three dispersion curves of the A0 mode are easily and promptly generated from a set of measurements obtained from a rapid ACT angle scan experiment. In addition, the phase velocity and group velocity polar characteristic wave curves are also computed to analyze experimentally the angular dependency of Lamb wave propagation. In comparison with the results from the theory, it is confirmed that using the ACT/LDV system and implementing simple Snell's law method is highly sensitive and effective in characterizing the dispersion curves of Lamb waves in composite structures as well as its angular dependency.

  17. A comparison measurement of nonlinear ultrasonic waves in tubes by a microphone and by an optical interferometric probe.

    Science.gov (United States)

    Slegrová, Zuzana; Bálek, Rudolf

    2005-03-01

    This paper deals with the analysis of ultrasonic fields inside waveguides generated by ultrasonic waves of high amplitude. These waves behave nonlinearly, so it is not possible to use standard linear equations to describe their behaviour. Therefore, we started with an experimental determination of the acoustic pressure of air in glass tubes. We chose two methods of measurement--by a microphone and by an optical interferometric probe. The conventional method by a microphone creates numerous problems, which can be avoided by using an optical method, a heterodyne laser interferometer.

  18. The Effect of Ultrasonic Waves on Sugar Extraction and Mechanical Properties of Sugar Beet

    Directory of Open Access Journals (Sweden)

    K Hedayati

    2013-09-01

    Full Text Available Sugar, which can be extracted from sugar cane and sugar beet, is one of the most important ingredients of food. Conducting more research to increase the extraction efficiency of sugar is necessary due to high production of sugar beet and its numerous processing units in northern Khorasan province. In this research, the effect of temperature, time and the frequency of ultrasonic waves on mechanical properties of sugar beet and its extraction rate of sugar in moisture content of 75% were studied. In this regard, an ultrasonic bath in laboratory scale was used. The studied parameters and their levels were frequency in three levels (zero, 25 and 45 KHz, temperature in three levels (25, 50 and 70 ° C and the imposed time of ultrasonic waves in three levels (10, 20 and 30 min. Samples were prepared using planned experiments and the results were compared with control sugar beet samples. A Saccharimeter was used to measure the concenteration of sugar in samples. Two different types of probe including semi-spherical end and the other one with sharpened edges were used to measure mechanical properties. The studied parameters of frequency, temperature and time showed significant effect on sugar extraction and their resulted effect in optimized levels revealed up to 56% increase in sugar extraction compared with control samples. The obtained values of elastic modulus and shear modulus showed a decreasing trend. The obtained values of total energy of rupture, the total energy of shear, the maximum force of rupture, and the yield point of rupture showed an increasing trend. The frequency had no significant effect on the yield point of rupture and shear force.

  19. Effect of Shear on Ultrasonic Flow Measurement Using Nonaxisymmetric Wave Modes

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2014-01-01

    Full Text Available Nonaxisymmetric wave propagation in an inviscid fluid with a pipeline shear flow is investigated. Mathematical equation is deduced from the conservations of mass and momentum, leading to a second-order differential equation in terms of the acoustic pressure. Meanwhile a general boundary condition is formulated to cover different types of wall configurations. A semianalytical method based on the Fourier-Bessel theory is provided to transform the differential equation to algebraic equations. Numerical analysis of phase velocity and wave attenuation in water is addressed in the laminar and turbulent flow. Meanwhile comparison among different kinds of boundary condition is given. In the end, the measurement performance of an ultrasonic flow meter is demonstrated.

  20. Limited-view ultrasonic guided wave tomography using an adaptive regularization method

    Science.gov (United States)

    Rao, Jing; Ratassepp, Madis; Fan, Zheng

    2016-11-01

    Ultrasonic guided waves are useful to assess the integrity of a structure from a remote location. Recently, tomography techniques have been developed to quantitatively estimate the thickness map of plate-like structures based on the dispersion characteristics of guided waves. In many applications only limited locations are available to place transducers. The missing viewing angles lead to artifacts which can degrade the image quality. To address this problem, this paper applies the regularization method to synthesize the missing components. The regularization technique is performed by an adaptive threshold approach to the limited view reconstruction. The effectiveness of this method combined with the full waveform inversion method is demonstrated by using numerical simulations as well as experiments on an irregularly shaped defect and two flat-bottom defects. The results indicate that the additional components obtained from the regularization method can significantly reduce the artifacts, leading to better reconstruction accuracy.

  1. Nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating embedded in water

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez, N.; Picó, R. [Instituto de Investigación para la Gestión Integrada de zonas Costeras, Universitat Politècnica de València, Paranimf 1, 46730 Grao de Gandia, València (Spain); Romero-García, V. [LUNAM Université, Université du Maine, LAUM UMR CNRS 6613, Av. O. Messiaen, 72085 Le Mans (France); Garcia-Raffi, L. M. [Instituto Universitario de Matemática Pura y Aplicada, Universitat Politècnica de València, Camino de Vera s/n, 46022 València (Spain); Staliunas, K. [ICREA, Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Colom, 11, E-08222 Terrassa, Barcelona (Spain)

    2015-11-16

    We report the nonlinear focusing of ultrasonic waves by an axisymmetric diffraction grating immersed in water. In the linear regime, the system presents high focal gain (32 dB), with a narrow beam-width and intense side lobes as it is common in focusing by Fresnel-like lenses. Activating the nonlinearity of the host medium by using high amplitude incident waves, the focusing properties of the lens dramatically change. Theoretical predictions show that the focal gain of the system extraordinary increases in the strongly nonlinear regime (Mach number of 6.1 × 10{sup −4}). Particularly, the harmonic generation is locally activated at the focal spot, and the second harmonic beam is characterized by strongly reduced side-lobes and an excellent beam profile as experiments show in agreement with theory. The results can motivate applications in medical therapy or second harmonic imaging.

  2. Effect of in-situ application of ultrasonic waves during formation of silver nanoparticles embedded in phospholipid membrane

    Science.gov (United States)

    Kim, Yongdeok; Hwan An, Hyeun; Bae Han, Won; Kim, Hee-Soo; Jun Kim, Suk; Seung Yoon, Chong

    2013-10-01

    Effect of in-situ application of ultrasonic waves (up to 1 MHz) on the Ag nanoparticles spontaneously produced inside the 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) membrane by thermal evaporation of Ag was studied by placing the membrane on a ultrasonic transducer during the metal deposition. Application of the ultrasonic vibration promoted spatial ordering of the deposited nanoparticles due to the induced phase transition from Lα to HII for DOPE. Arising from the agitation effect, particle size refinement, which depended on the amplitude of the ultrasonic vibration, was observed. It was also shown that a stiff gel state 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) membrane can be made locally permeable to incident Ag atoms by introducing DOPE molecules into the DPPC membrane as the Ag nanoparticles preferentially nucleated in the DOPE-rich region. Application of ultrasonic vibration with increasingly higher amplitude or frequency made the Ag nanoparticles uniformly distributed in the DPPC, suggesting that the permeability of the DPPC membrane can be temporarily increased without permanently damaging the membrane by addition of liquid crystalline lipids and subsequent application of ultrasonic waves.

  3. First-principle simulation of the acoustic radiation force on microparticles in ultrasonic standing waves

    DEFF Research Database (Denmark)

    Jensen, Mads Jakob Herring; Bruus, Henrik

    2013-01-01

    The recent development in the field of microparticle acoutophoresis in microsystems has led to an increased need for more accurate theoretical predections for the acoustic radiation force on a single microparticle in an ultrasonic standing wave. Increasingly detailed analytical solutions of this ......The recent development in the field of microparticle acoutophoresis in microsystems has led to an increased need for more accurate theoretical predections for the acoustic radiation force on a single microparticle in an ultrasonic standing wave. Increasingly detailed analytical solutions...... of this specific problem can be found in the literature [Settnes ans Bruus, Phys. Rev. E 85, 016327 (2012), and references therein], but none have included the complete contribution from thermoviscous effects. Here, we solve this problem numerically by applying a finite-element method to solve directly the mass...... (continuity), momentum (Navier-Stokes), and energy conservation equations using perturbation theory to second order in the imposed time-harmonic ultrasound field. In a two-stage calculation, we first solve the first-order equations resolving the thermoviscous boundary layer surrounding the microparticle...

  4. Ultrasonic torsional guided wave sensor for flow front monitoring inside molds.

    Science.gov (United States)

    Visvanathan, Karthik; Balasubramaniam, Krishnan

    2007-01-01

    Measuring the extent of flow of viscous fluids inside opaque molds has been a very important parameter in determining the quality of products in the manufacturing process such as injection molding and resin transfer molding. Hence, in this article, an ultrasonic torsional guided wave sensor has been discussed for monitoring the movement of flow front during filling of resins in opaque molds. A pair of piezoelectric normal shear transducers were used for generating and receiving the fundamental ultrasonic torsional guided wave mode in thin copper wires. The torsional mode was excited at one end of the wire, while the flowing viscous fluid progressively wet the other free end of the wire. The time of flight of the transient reflections of this fundamental mode from the air-fluid interface, where the wire enters the resin, was used to measure the position of the fluid flow front. Experiments were conducted on four fluids with different viscosity values. Two postprocessing algorithms were developed for enhancing the transient reflected signal and for suppressing the unwanted stationary signals. The algorithms were tested for cases where the reflected signals showed a poor signal to noise ratio.

  5. Standard practice for measuring the ultrasonic velocity in polyethylene tank walls using lateral longitudinal (LCR) waves

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This practice covers a procedure for measuring the ultrasonic velocities in the outer wall of polyethylene storage tanks. An angle beam lateral longitudinal (LCR) wave is excited with wedges along a circumferential chord of the tank wall. A digital ultrasonic flaw detector is used with sending-receiving search units in through transmission mode. The observed velocity is temperature corrected and compared to the expected velocity for a new, unexposed sample of material which is the same as the material being evaluated. The difference between the observed and temperature corrected velocities determines the degree of UV exposure of the tank. 1.2 The practice is intended for application to the outer surfaces of the wall of polyethylene tanks. Degradation typically occurs in an outer layer approximately 3.2-mm (0.125-in.) thick. Since the technique does not interrogate the inside wall of the tank, wall thickness is not a consideration other than to be aware of possible guided (Lamb) wave effects or reflection...

  6. Defects detection in typical positions of bend pipes using low-frequency ultrasonic guided wave

    Institute of Scientific and Technical Information of China (English)

    罗更生; 谭建平; 汪亮; 许焰

    2015-01-01

    In order to analyze the possibility of detecting defects in bend pipe using low-frequency ultrasonic guided wave, the propagation of T(0,1) mode and L(0,2) mode through straight-curved-straight pipe sections was studied. FE (finite element) models of bend pipe without defects and those with defects were introduced to analyze energy distribution, mode transition and defect detection of ultrasonic guided wave. FE simulation results were validated by experiments of four different bend pipes with circumferential defects in different positions. It is shown that most energy of T(0,1) mode or L(0,2) mode focuses on extrados of bend but little passes through intrados of bend, and T(0,1) mode or L(0,2) mode is converted to other possible non-axisymmetric modes when propagating through the bend and the defect after bend respectively. Furthermore, L(0,2) mode is more sensitive to circumferential notch than T(0,1) mode. The results of this work are beneficial for practical testing of pipes.

  7. A multiplexed two-wave mixing interferometer for laser ultrasonic measurements of material anisotropy

    Science.gov (United States)

    Zhou, Yi; Murray, Todd W.; Krishnaswamy, Sridhar

    2002-05-01

    A method to optically measure ultrasonic displacements simultaneously over an array of detection points has been developed. Optical phase gratings are used to create a detection-array of laser beams that are directed to the specimen. The detection array can be arranged in several ways on the test object. The scattered beams from the detection-array are collected and combined with a single reference beam in a photorefractive crystal to from a multiplexed two-wave mixing (MTWM) configuration. Each of the output beams from the photorefractive crystal is imaged on to a separate element of a photodetector array. The resulting MTWM system is capable of providing simultaneous optical detection (with high spatial resolution and sub-nanometer displacement sensitivities) at several points on a test object. The MTWM system can be used in several modes for laser ultrasonic NDE of flaws and materials characterization. In this paper, the MTWM is used to characterize material anisotropy. Surface acoustic waves (SAWs) are generated using a pulsed laser focused to a point on a test object. The resulting SAW propagation is monitored optically simultaneously at 8 points arranged circularly around the generating spot. The scattered beams from the eight detection points are processed simultaneously in the MTWM setup. The group velocity slowness curve is obtained directly from the measured signals from the MTWM array. Results are shown for silicon and quartz. It is shown that the MTWM enables rapid experimental determination of material anisotropy.

  8. The Measurement of Sucrose Content of Sugar Cane Using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Amoranto Trisnobudi, Tjia Liong Hoei, Enung Rosihan Nugraha

    2001-04-01

    Full Text Available The measurement of sucrose content of sugar cane is usually carried out by using polarimeter and Brix Wager scale. These two apparatus are operated manually so that the accuracy of the measurement results is depended on the operator skill. To overcome this problem we have developed an alternative method that can measure the sucrose content more quickly and accurately than the conventional methods. This new method was carried out by using ultrasonic waves whose velocity depends on the sucrose content. Firstly, the electronic apparatus used was calibrated with 37 samples of sugar cane with various sucrose content from 4.46 % to 7.29 %. The result of this calibration was an empirical equation between the ultrasonic wave velocity V and the sucrose content R, i.e. R = 2.65 V2 - 11,95 V + 17,65 where R in % and V in km/s. Then this equation was stored as database in a computer program that will be used to calculate the sucrose content. Finally, this sucrose content measurement system was tested by using 30 samples of sugar cane. The maximum error of the measurement result was 6.4 %.

  9. Temperature dependent E and G measurement of materials using ultrasonic guided waves

    Science.gov (United States)

    Periyannan, Suresh; Balasubramaniam, Krishnan

    2014-02-01

    A novel technique for measuring the moduli of elastic isotropic material as a function of temperature, using ultrasonic guided wave modes is presented here. These techniques can be used for measure the Young's modulus (E) and Shear Modulus (G) of material. Here, the L (0, 1) wave mode is used for measuring E and T(0,1) mode for G. The scope of measurement is made from room temperature to maximum utility temperature of material. In this work, the material is required in the form of a waveguide with an ultrasonic guided wave generator at one end and an embodiment (such as a notch or a bend) at the other end for obtaining reflected signals. The transducer is kept at room temperature while the end (along with the embodiment) is kept inside a heating device such as a temperature controlled furnace. The time of flight difference (δTOF), as a function of temperature, between the guided wave reflections from the embodiment and the end of the waveguide, is used to measure the material properties. The technique is based on the fact that, in addition to elongation of the waveguide, the sound speed in the materials also varies with temperature and is measurable from changes in the time of flight of signals. In addition, the ambient temperature of the waveguide end is measured using a calibrated thermocouple. Several materials were tested and the data was compared with values obtained from literature. For instance, Inconel -690 waveguide with embodiment of a 'L' bend was evaluated from 45°C to 1100°C at a frequency of 0.5 MHz L(0, 1) and T(0, 1) modes. The comparison between the literature values and the measured values were found to be in agreement with a regression correlation factor R=0.999 or better, for both E and G measurements. Advantages of the method over conventional methods of such measurements will also be discussed.

  10. Repeater F-waves are signs of motor unit pathology in polio survivors.

    Science.gov (United States)

    Hachisuka, Akiko; Komori, Tetsuo; Abe, Tatsuya; Hachisuka, Kenji

    2015-05-01

    The purpose of this study was to determine whether F-waves reveal electrophysiological features of anterior horn cells in polio survivors. Forty-three polio survivors and 20 healthy controls underwent motor nerve conduction studies of the median and tibial nerves bilaterally, including sampling of F-waves elicited by 100 stimuli and the determination of motor unit number estimation (MUNE). A significant increase in abnormally stereotyped ("repeater") F-waves and a reduction of F-wave persistence were observed in both nerves in the polio group as compared with the control group. Repeater F-waves had a negative correlation with MUNE. These trends in F-wave persistence and repeater F-waves after motor unit loss are characteristic findings in polio survivors. Repeater F-waves are a sign of motor unit pathology. © 2014 The Authors. Muscle & Nerve Published by Wiley Periodicals, Inc.

  11. A General Power Supply of Ultrasonic Motor (USM) Based on LabVIEW%一种基于虚拟仪器的超声电机通用电源

    Institute of Scientific and Technical Information of China (English)

    陈许英; 杨明

    2009-01-01

    The paper proposes a multi-frequencies,wide bandwidth and auto-recover protection power supply used to drive the ultrasonic motors (USM).The power supply uses the high frequency and high voltage amplifier to output the two-way voltage with 200 V of peak-peak value and its frequency is up to 300 kHz.Using virtual instrument of LabVIEW,it provides sine wave,square wave,triangle wave waveforms which the frequency,amplitude and phase can be adjustable.The power supply is also easy to incorporate with sensors to construct the control circuit of the ultrasonic motor.%介绍了一种用于超声电机的多频、宽带、具有自恢复保护电路的通用驱动电源.该电源采用高频高压功率放大器,可输出两路峰-峰值200 V的电压,频率可高达300 kHz;采用LabVIEW虚拟仪器技术,输出频率、幅值、相位都可调的正弦波、方波、三角波等波形;与传感器结合,该电源易于构成控制电路.

  12. A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint.

    Science.gov (United States)

    Li, Xiaoniu; Yao, Zhiyuan; Yang, Mojian

    2017-06-01

    A novel large thrust-weight ratio V-shaped linear ultrasonic motor with a flexible joint is proposed in this paper. The motor is comprised of a V-shaped transducer, a slider, a clamp, and a base. The V-shaped transducer consists of two piezoelectric beams connected through a flexible joint to form an appropriate coupling angle. The V-shaped motor is operated in the coupled longitudinal-bending mode. Longitudinal and bending movements are transferred by the flexible joint between the two beams. Compared with the coupled longitudinal-bending mode of the single piezoelectric beam or the symmetrical and asymmetrical modes of the previous V-shaped transducer, the coupled longitudinal-bending mode of the V-shaped transducer with a flexible joint provides higher vibration efficiency and more convenient mode conformance adjustment. A finite element model of the V-shaped transducer is created to numerically study the influence of geometrical parameters and to determine the final geometrical parameters. In this paper, three prototypes were then fabricated and experimentally investigated. The modal test results match well with the finite element analysis. The motor mechanical output characteristics of three different coupling angles θ indicate that V-90 (θ = 90°) is the optimal angle. The mechanical output experiments conducted using the V-90 prototype (Size: 59.4 mm × 30.7 mm × 4 mm) demonstrate that the maximum unloaded speed is 1.2 m/s under a voltage of 350 Vpp, and the maximum output force is 15 N under a voltage of 300 Vpp. The proposed novel V-shaped linear ultrasonic motor has a compact size and a simple structure with a large thrust-weight ratio (0.75 N/g) and high speed.

  13. Assembly and debugging technology for ultrasonic motor%超声波电机的装配调试技术

    Institute of Scientific and Technical Information of China (English)

    高跃民; 姬海英

    2011-01-01

    超声波电机的装配调试是超声波电机研制的重要环节,主要难点是压电振子粘接、预紧力调试及机电匹配调试.本文自主摸索出一套适合超声波电机快速小批量生产的装配和调试技术.采用摩擦材料、定子弹性体、压电陶瓷、柔性印制电路板的一体化粘接,解决压电振子的粘接难题;采用粗调和微调相结合的方法,快速完成机电匹配调试,缩短生产周期.形成一套规范化的装配调试方法及流程,并应用于超声波电机的小批量生产和研制,研制出的超声波电机微型扁平,体积为14 mm×14 mm×4 mm,输出力矩达到2 mN·m,通过功率谱密度(PSD)为0.2 g2/Hz的随机振动和-40℃~60℃的高低温试验,并集成应用到系统中实现步进驱动功能.%Assembly and debugging of ultrasonic motor are the important links of ultrasonic motor development. The bonding of piezo-electric vibrator and the match adjusting of drive-control circuit are the main difficulties. A set of bonding, assembly and adjusting methods for small batch production was explored. Integration bonding of friction material, piezoelectric ceramic, flexible Printed Circuit Board (PCB) achieves high adhesion and precise positioning. Combination of coarse and fine adjusting achieves the fast mechanical and electrical matching setting to shorten the cycle of product. This set of assembly and setting methods was successfully applied in batch product. A batch of ultrasonic motors was developed with the volume of 14 mm × 14 mm × 4 mm, output torque 2 mN·m, and passed the 0.2 g2/Hz PSD(Power Spectral Density) random vibration and temperature test from -40 ℃ to 60 ℃. The developed ultrasonic motors were integrated applied in system to realize step driving.

  14. Two-dimensional manipulation of microparticles using phase-controllable ultrasonic standing waves

    Science.gov (United States)

    Courtney, C. R. P.; Ong, C.-K.; Drinkwater, B. W.; Wilcox, P. D.; Grinenko, A.

    2012-05-01

    The ability to trap, and then manipulate, micro-particles in a fluid, is of interest as a research tool in the biosciences. Applications include tissue engineering, particle sorting and improving alignment with bio-sensors. This paper relates to the use of phase-controllable counter-propagating ultrasonic waves to generate a standing wave with pressure nodes whose positions are determined by the relative phases of the component counter-propagating travelling waves. As dense (relative to the fluid) particles are forced to nodes in the pressure field this allows particles to be trapped at particular points and moved to arbitrary positions. Counter-propagating waves are generated using pairs of opposing transducers, matched and backed to minimise reflection. Using one pair of transducers allows particles to be trapped and manipulated in one dimension. Using two pairs of transducers, positioned orthogonally, and adjusting the relative phases appropriately, allows trapping and manipulation in two dimensions. The device is shown experimentally to be capable of trapping and manipulating 10-micron-diameter polystyrene beads in two dimensions.

  15. Efficient methods to model the scattering of ultrasonic guided waves in 3D

    Science.gov (United States)

    Moreau, L.; Velichko, A.; Wilcox, P. D.

    2010-03-01

    The propagation of ultrasonic guided waves and their interaction with a defect is of interest to the nondestructive testing community. There is no general solution to the scattering problem and it is still an ongoing research topic. Due to the complexity of guided wave scattering problems, most existing models are related to the 2D case. However, thanks to the increase in computer calculation power, specific 3D problems can also be studied, with the help of numerical or semi-analytical methods. This paper describes two efficient methods aimed at modeling 3D scattering problems. The first method is the use of the Huygens' principle to reduce the size of finite element models. This principle allows the area of interest to be restricted to the very near field of the defect, for both the generation of the incident field and the modal decomposition of the scattered field. The second method consists of separating the 3D problem into two 2D problems for which the solutions are calculated and used to approximate the 3D solution. This can be used at low frequency-thickness products, where Lamb waves have a similar behavior to bulk waves. These two methods are presented briefly and compared on simple scattering cases.

  16. Using field programmable gate array hardware for the performance improvement of ultrasonic wave propagation imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Shan, Jaffry Syed [Hamdard University, Karachi (Pakistan); Abbas, Syed Haider; Lee, Jung Ryul [Dept. of Aerospace Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kang, Dong Hoon [Advanced Materials Research Team, Korea Railroad Research Institute, Uiwang (Korea, Republic of)

    2015-12-15

    Recently, wave propagation imaging based on laser scanning-generated elastic waves has been intensively used for nondestructive inspection. However, the proficiency of the conventional software based system reduces when the scan area is large since the processing time increases significantly due to unavoidable processor multitasking, where computing resources are shared with multiple processes. Hence, the field programmable gate array (FPGA) was introduced for a wave propagation imaging method in order to obtain extreme processing time reduction. An FPGA board was used for the design, implementing post-processing ultrasonic wave propagation imaging (UWPI). The results were compared with the conventional system and considerable improvement was observed, with at least 78% (scanning of 100x100mm{sup 2} with 0.5 mm interval) to 87.5% (scanning of 200x200mm{sup 2} with 0.5 mm interval) less processing time, strengthening the claim for the research. This new concept to implement FPGA technology into the UPI system will act as a break-through technology for full-scale automatic inspection.

  17. Transmission of ultrasonic waves at oblique incidence to composite laminates with spring-type interlayer interfaces.

    Science.gov (United States)

    Ishii, Yosuke; Biwa, Shiro

    2015-11-01

    The transmission characteristics of ultrasonic waves at oblique incidence to composite laminates are analyzed theoretically by the stiffness matrix method. The analysis takes into account the presence of thin resin-rich regions between adjacent plies as spring-type interfaces with normal and shear stiffnesses. The amplitude transmission coefficient of longitudinal wave through a unidirectional laminate immersed in water is shown to be significantly influenced by the frequency, the interlayer interfacial stiffnesses, and the incident angle. Using Floquet's theorem, the dispersion relation of the infinitely extended laminate structure is calculated and compared to the transmission coefficient of laminates of finite thickness. This reveals that the ranges of frequency and interfacial stiffnesses where the Floquet waves lie in the band-gaps agree well with those where the transmission coefficient of the finite layered structure is relatively small, indicating that the band-gaps appear even in the laminate with a finite number of plies. The amplitude transmission coefficient for an 11-ply carbon-epoxy unidirectional composite laminate is experimentally obtained for various frequencies and incident angles. The low-transmission zones observed in the experimental results, which are due to the critical angle of the quasi-longitudinal wave and the Bragg reflection, are shown to be favorably compared with the theory.

  18. Characteristics of the thermopiezoelectric stator of an ultrasonic motor%超声电机定子热机电耦合特性

    Institute of Scientific and Technical Information of China (English)

    芦小龙; 赵淳生

    2011-01-01

    An ultrasonic motor may be driven in some extreme hot or cold environment> and it will be affected by the structural , electric and thermal coupled fields. The performance of the ultrasonic motor is closely related to the response of the stator stimulated by the coupled thermopiezoelectric forces. This paper presents theoretical and experimental results of coupled fields' effect on the stator of a traveling-wave rotary ultrasonic motor. The energy functional equations of the stator were investigated and the coupled model was acquired by means of assumed mode method. The theoretical analyses include the static temperature field modeling of the stator deformation and the transient modeling of the stator under temperature loading and electric exciting. The finite element method was used to simulate the stator's response > and then differences between simulation and calculation were discussed. In order to evaluate the accuracy of the theoretical model, the heating vibration measurement system and the thermal deformation test system were built up. By using the experimental method, the temperature influence on stator's static deformation, modal frequency and vibrating amplitude was tested and compared with the analysis results. The theoretical and experimental study reveals the variation disciplines of stator's thermopiezoelectric characteristics. This paper provides some guidance for designing and optimizing ultrasonic motor for extreme applications.%应用于极端环境的超声电机会受到温度场、应力场和电场的共同作用,定子在热机电耦合激励下的响应与电机工作特性密切相关.以行波型旋转超声电机为对象建立定子的能量泛函,采用假设模态的方法得到了热机电耦合动力学模型.运用有限元方法对热机电耦合作用下的定子进行仿真,分析了与理论计算结果的差异.建立了定子热扫频试验平台和热变形试验平台,测定温度对定子稳态形变、模态频率和振

  19. Effect of particle-particle interactions on the acoustic radiation force in an ultrasonic standing wave

    Energy Technology Data Exchange (ETDEWEB)

    Lipkens, Bart, E-mail: blipkens@wne.edu [Mechanical Engineering, Western New England University, Springfield, Massachusetts, 01119 (United States); Ilinskii, Yurii A., E-mail: ilinskii@gmail.com; Zabolotskaya, Evgenia A., E-mail: zheniazabolotskaya@gmail.com [Applied Research Laboratories, The University of Texas at Austin, Austin, Texas 78713–8029 (United States)

    2015-10-28

    Ultrasonic standing waves are widely used for separation applications. In MEMS applications, a half wavelength standing wave field is generated perpendicular to a laminar flow. The acoustic radiation force exerted on the particle drives the particle to the center of the MEMS channel, where concentrated particles are harvested. In macro-scale applications, the ultrasonic standing wave spans multiple wavelengths. Examples of such applications are oil/water emulsion splitting [1], and blood/lipid separation [2]. In macro-scale applications, particles are typically trapped in the standing wave, resulting in clumping or coalescence of particles/droplets. Subsequent gravitational settling results in separation of the secondary phase. An often used expression for the radiation force on a particle is that derived by Gorkov [3]. The assumptions are that the particle size is small relative to the wavelength, and therefore, only monopole and dipole scattering contributions are used to calculate the radiation force. This framework seems satisfactory for MEMS scale applications where each particle is treated separately by the standing wave, and concentrations are typically low. In macro-scale applications, particle concentration is high, and particle clumping or droplet coalescence results in particle sizes not necessarily small relative to the wavelength. Ilinskii et al. developed a framework for calculation of the acoustic radiation force valid for any size particle [4]. However, this model does not take into account particle to particle effects, which can become important as particle concentration increases. It is known that an acoustic radiation force on a particle or a droplet is determined by the local field. An acoustic radiation force expression is developed that includes the effect of particle to particle interaction. The case of two neighboring particles is considered. The approach is based on sound scattering by the particles. The acoustic field at the location of

  20. Combined application of ultrasonic waves, magnetic fields and optical flow in the rehabilitation of patients and disabled people

    OpenAIRE

    Chukhraiev, N.; Vladimirov, A.; Vilcahuaman, L.; Zukow, W; Samosyuk, N.; Chukhraieva, E.; Butskaya, L.

    2016-01-01

    SHUPYK NATIONAL MEDICAL ACADEMY OF POSTGRADUATE EDUCATION PONTIFICAL CATHOLIC UNIVERSITY OF PERU RADOM UNIVERSITY SCM «MEDICAL INNOVATIVE TECHNOLOGIES»       Chukhraiev N., Vladimirov А., Vilcahuamаn L., Zukow W., Samosyuk N., Chukhraieva E., Butskaya L.             COMBINED APPLICATION OF ULTRASONIC WAVES, MAGNETIC FIELDS AND OPTICAL FLOW IN THE REHABILITATION OF P...

  1. Combined application of ultrasonic waves, magnetic fields and optical flow in the rehabilitation of patients and disabled people

    OpenAIRE

    Chukhraiev, N.; Vladimirov, A.; Vilcahuaman, L.; Zukow, W.; Samosyuk, N.; Chukhraieva, E.; Butskaya, L.

    2016-01-01

    SHUPYK NATIONAL MEDICAL ACADEMY OF POSTGRADUATE EDUCATION PONTIFICAL CATHOLIC UNIVERSITY OF PERU RADOM UNIVERSITY SCM «MEDICAL INNOVATIVE TECHNOLOGIES»       Chukhraiev N., Vladimirov А., Vilcahuamаn L., Zukow W., Samosyuk N., Chukhraieva E., Butskaya L.             COMBINED APPLICATION OF ULTRASONIC WAVES, MAGNETIC FIELDS AND OPTICAL FLOW IN THE REHABILITATION OF P...

  2. Optimization Design of Rotor of Ultrasonic Motor with Double Stators and Single Rotor%双定子单转子超声电机转子结构的优化设计

    Institute of Scientific and Technical Information of China (English)

    伍旺贤; 纪跃波; 陈美谦; 王涛

    2016-01-01

    为了避免超声电机工作时,转子也发生振动,以双定子单转子行波型旋转超声电机为研究对象,建立了该电机转子的参数化有限元模型,运用灵敏度分析的方法,分析了转子的模态频率对各个结构参数的灵敏程度。在此基础上,运用有限元软件ANSYS的结构优化分析工具,对转子进行了优化设计。优化后的转子的模态频率远离了电机定子的工作频率。%In observation of investigating the vibration of the rotor resulted from the running of an ultra⁃sonic motor, an ultrasonic motor with double stators and single rotor was taken as a reference. A parametric finite element model of the rotor of traveling wave ultrasonic motor with double stators and single rotor was built. The sensitivity of rotor�s modal frequency to the rotor�s structural parameters was calculated based on sensitivity analysis method. ANSYS was further employed for optimization design of the rotor in terms of sensi⁃tivity analysis. Results demonstrate that optimization design of the rotor is effective in keeping the modal fre⁃quency of rotor out of the working frequency of ultrasonic motor.

  3. Ultrasonic guided wave bondline evaluation of thick metallic structures with viscoelastic coatings and the demonstration of a novel mode sweep technique

    Science.gov (United States)

    Bostron, Jason

    Ultrasonic guided waves are becoming more widely used in nondestructive evaluation applications due to their efficiency in defect detection, ability to inspect hidden areas, and other reasons. This dissertation addresses two main topics: ultrasonic guided wave bond evaluation of thin and thick coatings on thick metallic structures, and the use of a novel phased array technique for optimal guided wave mode and frequency selection. (Abstract shortened by UMI.).

  4. Evaluation of debonding progress in composite bonded structures by ultrasonic wave sensing with fiber Bragg grating sensors

    Science.gov (United States)

    Okabe, Yoji; Kuwahara, Junichiro; Takeda, Nobuo; Ogisu, Toshimichi; Kojima, Seiji; Komatsuzaki, Shinji

    2006-03-01

    The authors are constructing a damage detection system using ultrasonic waves. In this system, a piezo-ceramic actuator generates ultrasonic waves in a carbon fiber reinforced plastic (CFRP) laminate. After the waves propagate in the laminate, transmitted waves are received by a fiber Bragg grating (FBG) sensor using a newly developed high-speed optical wavelength interrogation system. In this research, this system was applied to the evaluation of debonding progress in CFRP bonded structures. At first, small-diameter FBG sensors, whose cladding diameter is about 1/3 of common optical fibers, were embedded in an adhesive layer of a double-lap type coupon specimen consisting of CFRP quasi-isotropic laminates, and the ultrasonic wave was propagated through the debonded region. After that, the wavelet transform was applied to the received waveforms and the results showed clear difference depending on the debonding length. Hence, a new damage index was proposed, which could be obtained from the difference in the distribution of the wavelet transform coefficient. As a result, the damage index increased with an increase in the debonded area. Furthermore this system was applied to the skin/stringer structural element of airplanes made of CFRP laminates. Both of the waves received by a bonded FBG and by an embedded FBG changed sensitively to the debonding progress. Also, the damage index could evaluate the length of the debonding between the skin and the stringer.

  5. Design and characterization of an ultrasonic lamb-wave power delivery system.

    Science.gov (United States)

    Kural, Aleksander; Pullin, Rhys; Holford, Karen; Lees, Jonathan; Naylon, Jack; Paget, Christophe; Featherston, Carol

    2013-06-01

    In this paper, a novel design for an ultrasonic power transmission system designed for use in aircraft structural monitoring systems is described. The prototype system uses ultrasonic Lamb waves to carry energy along plates, such as those used in aircraft structures, and commercially available piezoelectric patch transducers as the transmitter and receiver. This sets it apart from other acoustic power transmission systems reported to date. The optimum configuration transmitted 12.7 mW of power across a distance of 54 cm in a 1.5-mm-thick aluminum plate, while being driven by a 20-Vpp, 35-kHz sinusoidal electric signal. This is in the same order of magnitude as the power required by the wireless sensors nodes of a structural health monitoring system currently being developed by Cardiff University and its partners. Thus, the power transmission system can be considered a viable component of the power source combination considered for the sensor nodes, which will also include vibration and thermal energy harvesting. The paper describes the design and optimization of the transmission and reception circuits with the use of inductive compensation. The use of laser vibrometry to characterize the transducers and to understand the signal propagation between them is also reported.

  6. Ultrasonic guided wave detection of scatterers on large clad steel plates

    Science.gov (United States)

    Gong, Peng; Harley, Joel B.; Berges, Mario; Junker, Warren R.; Greve, David W.; Oppenheim, Irving J.

    2016-04-01

    "Clad steel" refers to a thick carbon steel structural plate bonded to a corrosion resistant alloy (CRA) plate, such as stainless steel or titanium, and is widely used in industry to construct pressure vessels. The CRA resists the chemically aggressive environment on the interior, but cannot prevent the development of corrosion losses and cracks that limit the continued safe operation of such vessels. At present there are no practical methods to detect such defects from the exposed outer surface of the thick carbon steel plate, often necessitating removing such vessels from service and inspecting them visually from the interior. In previous research, sponsored by industry to detect and localize damage in pressurized piping systems under operational and environmental changes, we investigated a number of data-driven signal processing methods to extract damage information from ultrasonic guided wave pitch-catch records. We now apply those methods to relatively large clad steel plate specimens. We study a sparse array of wafer-type ultrasonic transducers adhered to the carbon steel surface, attempting to localize mass scatterers grease-coupled to the stainless steel surface. We discuss conditions under which localization is achieved by relatively simple first-arrival methods, and other conditions for which data-driven methods are needed; we also discuss observations of plate-like mode properties implied by these results.

  7. 超声波电动机的结构优化方法%Structural Optimization Methods for Ultrasonic Motors

    Institute of Scientific and Technical Information of China (English)

    潘芳煜; 李朝东

    2011-01-01

    超声波电动机是近年来工业界和科技界的研究热点,设计和制作高性能超声波电动机的必要手段之一是超声波电动机的结构优化.主要介绍了超声波电动机结构优化的发展状况,着重讨论了其优化目标、优化方法和求解环境;最后分析了现行优化方法的不足之处及未来发展方向.%In recent years, ultrasonic motors (USMs) have attracted more and more interests due to their characters. To design a perfect ultrasonic motor,the structural optimization is necessary and important. In this paper,the development of USM's structural optimization was prerented. First of all the targets and the methods of structural optimization were introduced. Then, the environment for solving the problems was mentioned. Finally,the disadvantages of the USM's structural optimization were described and its trend was predicted.

  8. A 2D spring model for the simulation of ultrasonic wave propagation in nonlinear hysteretic media.

    Science.gov (United States)

    Delsanto, P P; Gliozzi, A S; Hirsekorn, M; Nobili, M

    2006-07-01

    A two-dimensional (2D) approach to the simulation of ultrasonic wave propagation in nonclassical nonlinear (NCNL) media is presented. The approach represents the extension to 2D of a previously proposed one dimensional (1D) Spring Model, with the inclusion of a PM space treatment of the intersticial regions between grains. The extension to 2D is of great practical relevance for its potential applications in the field of quantitative nondestructive evaluation and material characterization, but it is also useful, from a theoretical point of view, to gain a better insight of the interaction mechanisms involved. The model is tested by means of virtual 2D experiments. The expected NCNL behaviors are qualitatively well reproduced.

  9. Ultrasonic Guided-Wave Scan System Used to Characterize Microstructure and Defects in Ceramic Composites

    Science.gov (United States)

    Roth, Don J.; Cosgriff, Laura M.; Martin, Richard E.; Verrilli, Michael J.; Bhatt, Ramakrishna T.

    2004-01-01

    Ceramic matrix composites (CMCs) are being developed for advanced aerospace propulsion applications to save weight, improve reuse capability, and increase performance. However, mechanical and environmental loads applied to CMCs can cause discrete flaws and distributed microdamage, significantly reducing desirable physical properties. Such microdamage includes fiber/matrix debonding (interface failure), matrix microcracking, fiber fracture and buckling, oxidation, and second phase formation. A recent study (ref. 1) of the durability of a C/SiC CMC discussed the requirement for improved nondestructive evaluation (NDE) methods for monitoring degradation in these materials. Distributed microdamage in CMCs has proven difficult to characterize nondestructively because of the complex microstructure and macrostructure of these materials. This year, an ultrasonic guided-wave scan system developed at the NASA Glenn Research Center was used to characterize various microstructural and flaw conditions in SiC/SiC (silicon carbide fiber in silicon carbide matrix) and C/SiC (carbon fiber in silicon carbide matrix) CMC samples.

  10. Improving performance of direct coal liquefaction through swelling with solvent under the radiation of ultrasonic wave

    Institute of Scientific and Technical Information of China (English)

    NI Xian-zhi; LI Ke-jian; WANG Li

    2004-01-01

    Three kinds of lower rank bituminous coals from Yanzhou mine and Tengxian mine from Shandong Province were treated and hydrogenated in the study. The test results show that the performance of hydrogenation liquefaction of the pretreated coals is improved markedly. Under the test condition of H2 initial pressure 8.2 MPa, addition of the oil yield of pretreated YZ1 coal is 69.76% compared with 62.53% of oil yield of untreated YZ1. Seminally the oil yield of pretreated YZ2 coal is 55.43% compared with20.88% of untreated YZ2 coal. The results of tests also prove that the improving degree of hydrogenation liquefaction of the pretreated coals is related with radiation duration when the radiation frequency and radiation power of ultrasonic wave are fixed.

  11. The Frequency Modification of Vibration for Multi-DOF Ultrasonic Motor%多自由度超声电机振动频率的修正

    Institute of Scientific and Technical Information of China (English)

    李小云; 张小凤; 郝君宇; 宋智广; 周方

    2012-01-01

    Multi-DOF ultrasonic motor is the combination of more than two ultrasonic vibration modes in accordance with a certain way. In this paper,the characteristics of the vibration of the complex pattern of vertical cylindrical curved multi-DOF ultrasonic motor are studied. The stator of the motor is composed of two groups of sandwich lamination oscillator. The motivation of one group of sandwich lamination piezoelectric voltage is to produce larger vertical vibration displacement; the other group of piezoelectric sandwich lamination, used to produce the two directions of the blending vibration, is composed of two longitudinal vibrations of piezoelectric patches and four bronze e-lectrodes. Referring to the calculated method of frequency of transducer, the frequency equation of motor longitudinal bending by the wave equation of the vertical bending vibration is derived. Considering the interactions of vertical bending vibration of the stator with multi-DOF, the frequency equation of motor longitudinal bending is modified. Comparing the theoretical results, the numerical simulation results and experimental results, the correctness of theoretical calculations is proved.%多自由度超声电机是将两种以上的超声振动模式按照一定的方式组合,通过在定子表面的椭圆运动实现转子的多自由度转动.该文对纵弯复合模式圆柱形多自由度超声电机的振动特性进行了研究,该电机的定子由两组夹心式振子组成:一组夹心式压电片在电压激励时能在纵向产生较大的振动位移;另一组夹心式压电片由2个纵向振动的压电片和4个铜电极组成,用于产生两个方向的弯曲振动.为了研究电机的工作特性,参照换能器频率的计算方法,通过纵弯振动的波动方程推导了电机纵弯振动频率方程,考虑多自由度工作时,电机定子纵弯振动的相互影响,对纵弯振动频率方程进行了修正,并将理论计算结果、数值仿真结果及实验测

  12. Model benchmarking and reference signals for angled-beam shear wave ultrasonic nondestructive evaluation (NDE) inspections

    Science.gov (United States)

    Aldrin, John C.; Hopkins, Deborah; Datuin, Marvin; Warchol, Mark; Warchol, Lyudmila; Forsyth, David S.; Buynak, Charlie; Lindgren, Eric A.

    2017-02-01

    For model benchmark studies, the accuracy of the model is typically evaluated based on the change in response relative to a selected reference signal. The use of a side drilled hole (SDH) in a plate was investigated as a reference signal for angled beam shear wave inspection for aircraft structure inspections of fastener sites. Systematic studies were performed with varying SDH depth and size, and varying the ultrasonic probe frequency, focal depth, and probe height. Increased error was observed with the simulation of angled shear wave beams in the near-field. Even more significant, asymmetry in real probes and the inherent sensitivity of signals in the near-field to subtle test conditions were found to provide a greater challenge with achieving model agreement. To achieve quality model benchmark results for this problem, it is critical to carefully align the probe with the part geometry, to verify symmetry in probe response, and ideally avoid using reference signals from the near-field response. Suggested reference signals for angled beam shear wave inspections include using the `through hole' corner specular reflection signal and the full skip' signal off of the far wall from the side drilled hole.

  13. Defect detection of pipes using Lyapunov dimension of Duffing oscillator based on ultrasonic guided waves

    Science.gov (United States)

    Wu, Jing; Wang, Yu; Zhang, Weiwei; Nie, Zhenhua; Lin, Rong; Ma, Hongwei

    2017-01-01

    This study proposes a novel small defect detection approach for steel pipes using the Lyapunov dimension (D) of the Duffing chaotic system based on ultrasonic guided waves. In this paper, inspection model is constructed by inputting the measured guided wave signal into the Duffing equation as the external turbulent driving force term and then Dis calculated. The properties of the Duffing system's noise immunity are first demonstrated theoretically based on the Lyapunov exponents. By comparing Dof the Duffing inspection system between the conditions of the inputted pure noise and the guided wave signal, the amplitude of the periodic force (F), the important parameter of the Duffing inspection system, could be determined. The values of other parameters of the Duffing inspection system are subsequently determined according to the numerical investigation. Furthermore, a time-moving window function is constructed to scan along the measured signal to locate the defect. And the small defect echo signal polluted by the noise is illustrated to prove the availability of the proposed method. Both numerical and experimental results show that the proposed approach can be used to improve the sensitivity of small defect detection and locate the small defect in pipes.

  14. Transverse and Oblique Long Bone Fracture Evaluation by Low Order Ultrasonic Guided Waves: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Ying Li

    2017-01-01

    Full Text Available Ultrasonic guided waves have recently been used in fracture evaluation and fracture healing monitoring. An axial transmission technique has been used to quantify the impact of the gap breakage width and fracture angle on the amplitudes of low order guided wave modes S0 and A0 under a 100 kHz narrowband excitation. In our two dimensional finite-difference time-domain (2D-FDTD simulation, the long bones are modeled as three layers with a soft tissue overlay and marrow underlay. The simulations of the transversely and obliquely fractured long bones show that the amplitudes of both S0 and A0 decrease as the gap breakage widens. Fixing the crack width, the increase of the fracture angle relative to the cross section perpendicular to the long axis enhances the amplitude of A0, while the amplitude of S0 shows a nonmonotonic trend with the decrease of the fracture angle. The amplitude ratio between the S0 and A0 modes is used to quantitatively evaluate the fracture width and angles. The study suggests that the low order guided wave modes S0 and A0 have potentials for transverse and oblique bone fracture evaluation and fracture healing monitoring.

  15. Measurement of the viscosity-density product using multiple reflections of ultrasonic shear horizontal waves.

    Science.gov (United States)

    Greenwood, Margaret S; Adamson, Justus D; Bond, Leonard J

    2006-12-22

    We have developed an on-line computer-controlled sensor, based on ultrasound reflection measurements, to determine the product of the viscosity and density of a liquid or slurry for Newtonian fluids and the shear impedance of the liquid for non-Newtonian fluids. A 14 MHz shear wave transducer is bonded to one side of a 45-90 degrees fused silica wedge and the base is in contract with the liquid. Twenty-eight echoes were observed due to the multiple reflections of an ultrasonic shear horizontal (SH) wave within the wedge. The fast Fourier transform of each echo was obtained for a liquid and for water, which serves as the calibration fluid, and the reflection coefficient at the solid-liquid interface was obtained. Data were obtained for 11 sugar water solutions ranging in concentration from 10% to 66% by weight. The viscosity values are shown to be in good agreement with those obtained independently using a laboratory viscometer. The data acquisition time is 14s and this can be reduced by judicious selection of the echoes for determining the reflection coefficient. The measurement of the density results in a determination of the viscosity for Newtonian fluids or the shear wave velocity for non-Newtonian fluids. The sensor can be deployed for process control in a pipeline, with the base of the wedge as part of the pipeline wall, or immersed in a tank.

  16. Ethanol separation from ethanol-water solution by ultrasonic atomization and its proposed mechanism based on parametric decay instability of capillary wave

    Science.gov (United States)

    Sato, Masanori; Matsuura, Kazuo; Fujii, Toshitaka

    2001-02-01

    We show the experimental data of selective ethanol separation from ethanol-water solution, using ultrasonic atomization. Pure ethanol could be obtained directly from a solution with several mol% ethanol-water solution at 10 °C. This result can be explained in terms of parametric decay instability of capillary wave, in which high localization and accumulation of acoustic energy occur, leading to ultrasonic atomization. That is, parametric decay instability condenses the energy of longitudinal waves in a highly localized surface area of the capillary wave, and causes ultrasonic atomization.

  17. Research on Linear Ultrasonic Motor Based on Longitudinal Vibrate Mode of Pole%基于杆纵振的直线超声电机研究

    Institute of Scientific and Technical Information of China (English)

    曾劲松; 雷向红

    2011-01-01

    根据当前直线超声电机的特点,研制了一种新型的基于杆纵向振动超声电机,分析了电机的工作原理,并做出了样机.实验证明电机在施加合理的电压信号下能够实现往复的直线运动.%According to the characteristics of linear ultrasonic motor at present, developed a new linear ultrasonic motor based on longitudinal vibrate mode of pole. Analyzed the work principle of this motor, and make a machine. The experiment proves that the motor can implement bilateral motion under the reasonable electrical signal.

  18. In-situ measurement of permeability of a porous interface using the ultrasonic slow wave

    Science.gov (United States)

    Lin, Lin

    2011-12-01

    Porous materials are an important class of materials. They occur in natural substances such as oil or water bearing rocks, marine sediment, biological tissues (e.g. bones), granular materials and man made materials such as separation membranes, thermal insulators, ceramics and fuel cells. Porous materials have been used in many areas of applied science and engineering. Understanding of porous media plays an important role in areas such as experimental acoustics, geo-mechanics, geophysics, biophysics, material science. Among the number of parameters describing porous materials, the permeability is often the reason the porous structure is of interest. Permeability is a measurement of the ability of a porous material to transmit fluid. At an interface, permeability describes the flow of fluid into or out of a porous media Ultrasound has been widely used for flaw detection and material characterization. Studies show that there are three waves that exist in porous materials: the longitudinal and shear wave that exist in other solid materials and the slow longitudinal wave that only exists in porous materials. This slow longitudinal wave can only be generated and propagated above a critical frequency. Measuring the critical frequency provides information about the intrinsic permeability of a porous interface. This thesis presents a new technique developed for an in-situ permeability measurement using measurement of slow wave. In this work, an exact solution for the critical wave number for the slow wave has been developed and showed suitable for measuring the permeability of porous materials. A computer model of the reflection coefficient at the interface of fluid/porous media has been developed for the acoustic measurement. Ultrasonic experiments confirmed the sensitivity of this technique to changes in permeability and fluid viscosity. A flow cell test has been performed to show one potential industrial application of this technique by showing open pore and closed pore

  19. Development and preliminary evaluation of an ultrasonic motor actuated needle guide for 3T MRI-guided transperineal prostate interventions

    Science.gov (United States)

    Song, Sang-Eun; Tokuda, Junichi; Tuncali, Kemal; Tempany, Clare; Hata, Nobuhiko

    2012-02-01

    Image guided prostate interventions have been accelerated by Magnetic Resonance Imaging (MRI) and robotic technologies in the past few years. However, transrectal ultrasound (TRUS) guided procedure still remains as vast majority in clinical practice due to engineering and clinical complexity of the MRI-guided robotic interventions. Subsequently, great advantages and increasing availability of MRI have not been utilized at its maximum capacity in clinic. To benefit patients from the advantages of MRI, we developed an MRI-compatible motorized needle guide device "Smart Template" that resembles a conventional prostate template to perform MRI-guided prostate interventions with minimal changes in the clinical procedure. The requirements and specifications of the Smart Template were identified from our latest MRI-guided intervention system that has been clinically used in manual mode for prostate biopsy. Smart Template consists of vertical and horizontal crossbars that are driven by two ultrasonic motors via timing-belt and mitergear transmissions. Navigation software that controls the crossbar position to provide needle insertion positions was also developed. The software can be operated independently or interactively with an open-source navigation software, 3D Slicer, that has been developed for prostate intervention. As preliminary evaluation, MRI distortion and SNR test were conducted. Significant MRI distortion was found close to the threaded brass alloy components of the template. However, the affected volume was limited outside the clinical region of interest. SNR values over routine MRI scan sequences for prostate biopsy indicated insignificant image degradation during the presence of the robotic system and actuation of the ultrasonic motors.

  20. Transducer-type bi-directional linear ultrasonic motor and experiment

    Institute of Scientific and Technical Information of China (English)

    CHU Xiangcheng; CHEN Zaili

    2002-01-01

    A transducer-type bi-directional linear ultrasonic notor is presented. It has the features of flexible bi-directional drive, simple construction and easy control, etc. The characteristics parameters of the prototype are: frequency 21.46 kHz, maximum moving speed 400 mm/s under pre-load of 3.2 N, maximum thrust 2.1 N under pre-load of 1.6 N. The influence of phase shift and vibration amplitude of ultrasonic transducers on ideal elliptical locus and output characteristics are investigated with theoretical and experimental methods.

  1. Imaging ultrasonic dispersive guided wave energy in long bones using linear radon transform.

    Science.gov (United States)

    Tran, Tho N H T; Nguyen, Kim-Cuong T; Sacchi, Mauricio D; Le, Lawrence H

    2014-11-01

    Multichannel analysis of dispersive ultrasonic energy requires a reliable mapping of the data from the time-distance (t-x) domain to the frequency-wavenumber (f-k) or frequency-phase velocity (f-c) domain. The mapping is usually performed with the classic 2-D Fourier transform (FT) with a subsequent substitution and interpolation via c = 2πf/k. The extracted dispersion trajectories of the guided modes lack the resolution in the transformed plane to discriminate wave modes. The resolving power associated with the FT is closely linked to the aperture of the recorded data. Here, we present a linear Radon transform (RT) to image the dispersive energies of the recorded ultrasound wave fields. The RT is posed as an inverse problem, which allows implementation of the regularization strategy to enhance the focusing power. We choose a Cauchy regularization for the high-resolution RT. Three forms of Radon transform: adjoint, damped least-squares, and high-resolution are described, and are compared with respect to robustness using simulated and cervine bone data. The RT also depends on the data aperture, but not as severely as does the FT. With the RT, the resolution of the dispersion panel could be improved up to around 300% over that of the FT. Among the Radon solutions, the high-resolution RT delineated the guided wave energy with much better imaging resolution (at least 110%) than the other two forms. The Radon operator can also accommodate unevenly spaced records. The results of the study suggest that the high-resolution RT is a valuable imaging tool to extract dispersive guided wave energies under limited aperture.

  2. 基于摩擦模型的超声波电动机速度控制%Speed Control of Ultrasonic Motor Based on Friction Model

    Institute of Scientific and Technical Information of China (English)

    李鸿征; 王春霞

    2012-01-01

    Friction part of the system was compensated and a whole model of ultrasonic motor control program was built combined with PID controller when PID control scheme was used for ultrasonic motor. Three control parameters were a-chieved by the Z-N method, and the control of ultrasonic motor based on LuGre friction was accomplished. Simulation results verify the feasibility and the efficiency of PID control algorithm using for ultrasonic motor friction compensation.%对超声波电动机使用PID控制方案时,首先要对系统的摩擦环节进行补偿,建立一个整体超声波电动机模型控制方案,然后再结合PID控制器进行控制.使用Z-N法得到了控制器的三个控制参数,实现基于LuGre摩擦模型的超声波电动机模型控制,通过仿真实验验证对比,证明了对超声波电动机摩擦补偿后使用PID控制算法的可行性和有效性.

  3. On the development and testing of a guided ultrasonic wave array for structural integrity monitoring.

    Science.gov (United States)

    Fromme, Paul; Wilcox, Paul D; Lowe, Michael J S; Cawley, Peter

    2006-04-01

    The prototype of a guided ultrasonic wave array for the structural integrity monitoring of large, plate-like structures has been designed, built, and tested. The development of suitably small transducers for the excitation and measurement of the first antisymmetric Lamb wave mode Ao is described. The array design consists of a ring of 32 transducers, permanently bonded to the structure with a protective membrane, in a compact housing with the necessary multiplexing electronics. Using a phased addition algorithm with dispersion compensation and deconvolution in the wavenumber domain, a good dynamic range can be achieved with a limited number of transducers. Limitations in the transducer design and manufacture restricted the overall dynamic range achieved to 27 dB. Laboratory measurements for a steel plate containing various defects have been performed. The results for standard defects are compared to theoretical predictions and the sensitivity of the array device for defect detection has been established. Simulated corrosion pitting and a defect cut with an angle grinder simulating general corrosion were detected.

  4. Plane Wave Imaging for ultrasonic non-destructive testing: Generalization to multimodal imaging.

    Science.gov (United States)

    Le Jeune, Léonard; Robert, Sébastien; Lopez Villaverde, Eduardo; Prada, Claire

    2016-01-01

    This paper describes a new ultrasonic array imaging method for Non-Destructive Testing (NDT) which is derived from the medical Plane Wave Imaging (PWI) technique. The objective is to perform fast ultrasound imaging with high image quality. The approach is to transmit plane waves at several angles and to record the back-scattered signals with all the array elements. Focusing in receive is then achieved by coherent summations of the signals in every point of a region of interest. The medical PWI is generalized to immersion setups where water acts as a coupling medium and to multimodal (direct, half-skip modes) imaging in order to detect different types of defects (inclusions, porosities, cracks). This method is compared to the Total Focusing Method (TFM) which is the reference imaging technique in NDT. First, the two post-processing algorithms are described. Then experimental results with the array probe either in contact or in immersion are presented. A good agreement between the TFM and the PWI is observed, with three to ten times less transmissions required for the PWI.

  5. Precise spatial control of cavitation erosion in a vessel phantom by using an ultrasonic standing wave.

    Science.gov (United States)

    Shi, Aiwei; Huang, Peixuan; Guo, Shifang; Zhao, Lu; Jia, Yingjie; Zong, Yujin; Wan, Mingxi

    2016-07-01

    In atherosclerotic inducement in animal models, the conventionally used balloon injury is invasive, produces excessive vessel injuries at unpredictable locations and is inconvenient in arterioles. Fortunately, cavitation erosion, which plays an important role in therapeutic ultrasound in blood vessels, has the potential to induce atherosclerosis noninvasively at predictable sites. In this study, precise spatial control of cavitation erosion for superficial lesions in a vessel phantom was realised by using an ultrasonic standing wave (USW) with the participation of cavitation nuclei and medium-intensity ultrasound pulses. The superficial vessel erosions were restricted between adjacent pressure nodes, which were 0.87 mm apart in the USW field of 1 MHz. The erosion positions could be shifted along the vessel by nodal modulation under a submillimetre-scale accuracy without moving the ultrasound transducers. Moreover, the cavitation erosion of the proximal or distal wall could be determined by the types of cavitation nuclei and their corresponding cavitation pulses, i.e., phase-change microbubbles with cavitation pulses of 5 MHz and SonoVue microbubbles with cavitation pulses of 1 MHz. Effects of acoustic parameters of the cavitation pulses on the cavitation erosions were investigated. The flow conditions in the experiments were considered and discussed. Compared to only using travelling waves, the proposed method in this paper improves the controllability of the cavitation erosion and reduces the erosion depth, providing a more suitable approach for vessel endothelial injury while avoiding haemorrhage.

  6. Plate-like structure health monitoring based on ultrasonic guided wave technology by using bonded piezoelectric ceramic wafers

    Science.gov (United States)

    Liu, Zenghua; Zhao, Jichen; He, Cunfu; Wu, Bin

    2008-11-01

    Piezoelectric ceramic wafers are applied for the excitation and detection of ultrasonic guided waves to determine the health state of plate-like structures. Two PZT wafers, whose diameter is 11mm and thickness is 0.4mm respectively, are bonded permanently on the surface of a 1mm thick aluminum plate. One of these wafers is actuated by sinusoidal tone burst at various frequencies ranging from 100kHz to 500kHz, the other one is used as a receiver for acquiring ultrasonic guided wave signals. According to the amplitudes and shapes of these received signals, guided wave modes and their proper frequency range by using these wafers are determined. For the improvement of the signal-to-noise ratio, the Daubechies wavelet of order 40 is used for signal denoising as the mother wavelet. Furthermore, the detection of an artificial cylindrical through-hole defect is achieved by using S0 at 300kHz. Experimental results show that it is feasible and effective to detect defects in plate-like structures based on ultrasonic guided wave technology by using bonded piezoelectric ceramic wafers.

  7. Tracking Control of an Ultrasonic Linear Motor Actuated Stage Using a Sliding-mode Controller with Friction Compensation

    Directory of Open Access Journals (Sweden)

    Chih-Jer Lin

    2015-02-01

    Full Text Available The purpose of this paper is to investigate the nonlinear friction and compensation for a piezoelectric ceramic ultrasonic motor (USM. Although the architecture of the USM is different from the general electric-mechanical motor, the mathematic model for the USM motor can use the same friction model to formulate the friction phenomenon. To establish the feed-forward controller, the system identification for the USM is needed to study to design the model-based controller. To obtain the optimal system parameters of the USM, PSO and CSS algorithms are studied to identify the system parameters for the nonlinear friction model. For the controller design, a non-model based controller, using back-propagation neural network controller to perform tracking tasks, and the model-based controller, which consists of the feed-forward controller based on the system identification and the sliding-mode control, are discussed in this paper. Finally, the two real-time tracking tasks are used to validate the proposed method.

  8. A dendritic mechanism for decoding traveling waves: principles and applications to motor cortex.

    Directory of Open Access Journals (Sweden)

    Stewart Heitmann

    2013-10-01

    Full Text Available Traveling waves of neuronal oscillations have been observed in many cortical regions, including the motor and sensory cortex. Such waves are often modulated in a task-dependent fashion although their precise functional role remains a matter of debate. Here we conjecture that the cortex can utilize the direction and wavelength of traveling waves to encode information. We present a novel neural mechanism by which such information may be decoded by the spatial arrangement of receptors within the dendritic receptor field. In particular, we show how the density distributions of excitatory and inhibitory receptors can combine to act as a spatial filter of wave patterns. The proposed dendritic mechanism ensures that the neuron selectively responds to specific wave patterns, thus constituting a neural basis of pattern decoding. We validate this proposal in the descending motor system, where we model the large receptor fields of the pyramidal tract neurons - the principle outputs of the motor cortex - decoding motor commands encoded in the direction of traveling wave patterns in motor cortex. We use an existing model of field oscillations in motor cortex to investigate how the topology of the pyramidal cell receptor field acts to tune the cells responses to specific oscillatory wave patterns, even when those patterns are highly degraded. The model replicates key findings of the descending motor system during simple motor tasks, including variable interspike intervals and weak corticospinal coherence. By additionally showing how the nature of the wave patterns can be controlled by modulating the topology of local intra-cortical connections, we hence propose a novel integrated neuronal model of encoding and decoding motor commands.

  9. CFD modeling of convection heat transfer using 1.7 MHz and 24 kHz ultrasonic waves: a comparative study

    Science.gov (United States)

    Dehbani, Maryam; Rahimi, Masoud; Abolhasani, Mahdieh; Maghsoodi, Abbas; Afshar, Parisa Ghaderi; Dodmantipi, Ali Reza; Alsairafi, Ammar A.

    2014-09-01

    The effects of 24 kHz and 1.7 MHz ultrasonic waves on heat transfer from a thin platinum wire are investigated. The results revealed that the 1.7 MHz ultrasound waves could increase the heat transfer rate more efficiently than the lower frequency one. The CFD modeling of ultrasonication was performed to compare heat transfer, predict fluid flow patterns. The CFD results were validated by the experimental results with an excellent agreement.

  10. Single-phase driven ultrasonic motor using two orthogonal bending modes of sandwiching piezo-ceramic plates

    Science.gov (United States)

    Ma, Yuting; Choi, Minkyu; Uchino, Kenji

    2016-11-01

    A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44.8 kHz, was experimentally characterized, and a maximum torque of 2 mN m was obtained. Maximum power of 2.3 mW and efficiency of 9% were produced with a load of 0.8 mN m at a rotation speed of 27 rpm.

  11. Recurrent RBFN-based fuzzy neural network control for X-Y-theta motion control stage using linear ultrasonic motors.

    Science.gov (United States)

    Lin, Faa-Jeng; Shieh, Po-Huang

    2006-12-01

    A recurrent radial basis function network (RBFN) based fuzzy neural network (FNN) control system is proposed to control the position of an X-Y-theta motion control stage using linear ultrasonic motors (LUSMs) to track various contours in this study. The proposed recurrent RBFN-based FNN combines the merits of self-constructing fuzzy neural network (SCFNN), recurrent neural network (RNN), and RBFN. Moreover, the structure and the parameter learning phases of the recurrent RBFN-based FNN are performed concurrently and on line. The structure learning is based on the partition of input space, and the parameter learning is based on the supervised gradient decent method using a delta adaptation law. The experimental results due to various contours show that the dynamic behaviors of the proposed recurrent RBFN-based FNN control system are robust with regard to uncertainties.

  12. Single-phase driven ultrasonic motor using two orthogonal bending modes of sandwiching piezo-ceramic plates.

    Science.gov (United States)

    Ma, Yuting; Choi, Minkyu; Uchino, Kenji

    2016-11-01

    A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44.8 kHz, was experimentally characterized, and a maximum torque of 2 mN m was obtained. Maximum power of 2.3 mW and efficiency of 9% were produced with a load of 0.8 mN m at a rotation speed of 27 rpm.

  13. Classification of Low Velocity Impactors Using Spiral Sensing of Acousto-Ultrasonic Waves

    Science.gov (United States)

    Agbasi, Chijioke Raphael

    The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from nonlinearity and variability in the AUS signals due to materials, geometry, boundary conditions, wave dispersion, environmental conditions, sensor and hardware calibration etc. It is found that the frequency and speed of the guided wave generated in the plate can be quantized based on the impactor's relationship with the plate (i.e. the wave speed and the impactor's mechanical properties are coupled). In this work, in order to characterize the impact location and mechanical properties of imapctors, nonlinear transient phenomenon is empirically studied to decouple the understanding using the dominant frequency band (DFB) and Lag Index (LI) of the acousto-ultrasonic signals. Next the understanding was correlated with the elastic modulus of the impactor to predict transmitted force histories. The proposed method presented in this thesis is especially applicable for SHM where sensors cannot be widely or randomly distributed. Thus a strategic organization and localization of the sensors is achieved by implementing the geometric configuration of Theodorous Spiral Sensor Cluster (TSSC). The performance of TSSC in characterizing the impactor types are compared with other conventional sensor clusters (e.g. square, circular, random etc.) and it is shown that the TSSC is advantageous over

  14. 超声波电动机自动优化设计研究%Research on Automatic Optimization Design of Ultrasonic Motors

    Institute of Scientific and Technical Information of China (English)

    庞亚飞; 杨明

    2011-01-01

    超声波电动机的优化设计包含振动模态优化,激励方式或区域设定,电机结构、尺寸优化等等,以满足电机工作需求并改善其输出性能.介绍了一种基于MATLAB和ANSYS的自动优化方法,即利用MATLAB运行优化算法,建立APDL参数化分析模型,并反复调用ANSYS分析对超声波电动机进行自动优化.文中以矩形板超声波电动机的驱动足优化为例,给出了驱动足的位置设定和形状优化过程,并对MATLAB与ANSYS程序之间的调用、接口及数据交互方面做了详细说明.%The optimum design of ultrasonic motors involving the optimization of vibration mode, the determination of excitation pattern and area, the structural optimization, etc, was proposed to meet the motor work demand and to improve the motor output.A method for automatic optimization of ultrasonic motors based on MATLAB and ANSYS was presented in this paper, in which MATLAB conducted the optimization algorithm, established the parametric model based on APDL, and repeatedly called the ANSYS analysis to optimize the ultrasonic motor automatically.For instance, location setting and shape optimization of the driving tip of rectangular plate ultrasonic motors were investigated, and the call, interface and data exchange between MATLAB and ANSYS were discussed in detail.

  15. Analysis of laser generated ultrasonic wave frequency characteristics induced by a partially closed surface-breaking crack.

    Science.gov (United States)

    Li, Jia; Zhang, Hongchao; Ni, Chenyin; Shen, Zhonghua

    2013-06-20

    This research focuses on analyzing the frequency characteristics of ultrasonic waves induced by a partially closed surface-breaking crack. When acoustic waves interact with the crack, transmission, reflection, and mode conversions occur and the frequency characteristics of signals perform obvious changes. A pulsed laser line source is used to generate ultrasonic waves in the sample with a partially closed surface-breaking crack, and one can see how the frequency characteristics of detected signals change as the pulsed laser beam scans across the sample surface. The optical deflection beam method is developed to detect the ultrasonic signals experimentally. The fast Fourier transform (FFT) is used to analyze the time-domain data, and the FFT data are visualized by a B-scan plot. A clear disruption in the B-scan can be observed when the laser beam illuminates directly onto the crack, which is due to the changes of frequency characteristics induced by the partially closed crack. A frequency-domain B-scan of numerical simulation results is presented, and the clear disruption can also be observed clearly.

  16. Amplitude modulation drive to rectangular-plate linear ultrasonic motors with vibrators dimensions 8 mm x 2.16 mm X 1 mm.

    Science.gov (United States)

    Ming, Yang; Hanson, Ben; Levesley, Martin C; Walker, Peter G; Watterson, Kevin G

    2006-12-01

    In this paper, to exploit the contribution from not only the stators but also from other parts of miniature ultrasonic motors, an amplitude modulation drive is proposed to drive a miniature linear ultrasonic motor consisting of two rectangular piezoelectric ceramic plates. Using finite-element software, the first longitudinal and second lateral-bending frequencies of the vibrator are shown to be very close when its dimensions are 8 mm x 2.16 mm x 1 mm. So one single frequency power should be able to drive the motor. However, in practice the motor is found to be hard to move with a single frequency power because of its small vibration amplitudes and big frequency difference between its longitudinal and bending resonance, which is induced by the boundary condition variation. To drive the motor effectively, an amplitude modulation drive is used by superimposing two signals with nearly the same frequencies, around the resonant frequency of the vibrators of the linear motor. When the amplitude modulation frequency is close to the resonant frequency of the vibrator's surroundings, experimental results show that the linear motor can move back and forward with a maximum thrust force (over 0.016 N) and a maximum velocity (over 50 mm/s).

  17. Sleep spindle and slow wave frequency reflect motor skill performance in primary school-age children

    NARCIS (Netherlands)

    Astill, Rebecca G; Piantoni, Giovanni; Raymann, Roy J E M; Vis, Jose C; Coppens, Joris E; Walker, Matthew P; Stickgold, Robert; Van Der Werf, Ysbrand D; Van Someren, Eus J W

    2014-01-01

    Background and Aim: The role of sleep in the enhancement of motor skills has been studied extensively in adults. We aimed to determine involvement of sleep and characteristics of spindles and slow waves in a motor skill in children. Hypothesis: We hypothesized sleep-dependence of skill enhancement a

  18. Estimation of temperature elevation generated by ultrasonic irradiation in biological tissues using the thermal wave method

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-Zhou; Zhu Yi; Zhang Fei; Gong Xiu-Fen

    2013-01-01

    In most previous models,simulation of the temperature generation in tissue is based on the Pennes bio-heat transfer equation,which implies an instantaneous thermal energy deposition in the medium.Due to the long thermal relaxation time τ (20 s-30 s) in biological tissues,the actual temperature elevation during clinical treatments could be different from the value predicted by the Pennes bioheat equation.The thermal wave model of bio-heat transfer (TWMBT) defines a thermal relaxation time to describe the tissue heating from ultrasound exposure.In this paper,COMSOL Multiphysics 3.5a,a finite element method software package,is used to simulate the temperature response in tissues based on Pennes and TWMBT equations.We further discuss different factors in the bio-heat transfer model on the influence of the temperature rising and it is found that the temperature response in tissue under ultrasound exposure is a rising process with a declining rate.The thermal relaxation time inhibits the temperature elevation at the beginning of ultrasonic heating.Besides,thermal relaxation in TWMBT leads to lower temperature estimation than that based on Pennes equation during the same period of time.The blood flow carrying heat dominates most to the decline of temperature rising rate and the influence increases with temperature rising.On the contrary,heat diffusion,which can be described by thermal conductivity,has little effect on the temperature rising.

  19. 3D attitude measurement by means of spread spectrum modulated ultrasonic wave

    Institute of Scientific and Technical Information of China (English)

    Shinji Ohyama; Hiroshi Iwasawa; Sang Il Ko; Junya Takayama

    2007-01-01

    Local position and attitude measurement methods are necessary for the navigation of autonomous robots and the other applications. In this paper, a 3D attitude measurement method is proposed. This method uses the spread spectrum modulated ultrasonic wave for the measurement of the pseudo-distance of each pathway between transmitter and receiver elements that are arranged in an array. The relative attitude between transmitter and receiver unit could be calculated from the relationship between these pseudo-distances. The use of spread spectrum modulation enables the high accuracy, noise tolerance, and coexistence of multiple transmitter devices by code division multiple access (CDMA) between transmitter and receiver elements. A pair of transmitter and receiver prototype for proposed method was manufactured, and the fundamental performance was examined in experiments. As a result, accuracy of σ = 0.78 mm in the pseudo-distance measurement of each pathway between transmitter and receiver elements was confirmed, and about 0.01 rad resolution in the attitude measurement was also confirmed.

  20. Observation of ultrasonic guided wave propagation behaviours in pre-stressed multi-wire structures.

    Science.gov (United States)

    Liu, Xiucheng; Wu, Bin; Qin, Fei; He, Cunfu; Han, Qiang

    2017-01-01

    Ultrasonic guided wave (UGW) is a promising technique for nondestructive testing of pre-stressed multi-wire structures, such as steel strand and wire rope. The understanding of the propagation behaviours of UGW in these structures is a priority to applications. In the present study, first the properties of the UGW missing frequency band in the pre-stressed seven-wire steel strand is experimentally examined. The high correlation between the observed results and the previously published findings proves the feasibility of the magnetostrictive sensor (MsS) based testing method. The evolution of missing frequency band of UGW in slightly tensioned steel strand is discussed. Two calibration equations representing the relationship between the missing band parameters and the tensile force are given to derive a new tensile force measurement method, which is capable of measuring an incremental of stress of approximately 3MPa. Second, the effects of tensile force on the UGW propagation behaviours in three types of complicated steel wire ropes are alternatively investigated based on the short time Fourier transform (STFT) results of the received direct transmission wave (DTW) signals. The observed inherent missing frequency band of the longitudinal mode UGW in the pre-stressed steel wire rope and its shifting to a higher frequency range as the increases of the applied tensile force are reported for the first time. The influence of applied tensile force on the amplitude of the DTW signal and the unique UGW energy jump behaviour observed in a wire rope of 16.0mm, 6×Fi(29)+IWRC are also investigated, despite the fact that they cannot yet be explained.

  1. FPGA Implementation of an Amplitude-Modulated Continuous-Wave Ultrasonic Ranger Using Restructured Phase-Locking Scheme

    Directory of Open Access Journals (Sweden)

    P. Sumathi

    2010-01-01

    Full Text Available An accurate ultrasonic range finder employing Sliding Discrete Fourier Transform (SDFT based restructured phase-locked loop (RPLL, which is an improved version of the recently proposed integrated phase-locking scheme (IPLL, has been expounded. This range finder principally utilizes amplitude-modulated ultrasonic waves assisted by an infrared (IR pilot signal. The phase shift between the envelope of the reference IR pilot signal and that of the received ultrasonic signal is proportional to the range. The extracted envelopes are filtered by SDFT without introducing any additional phase shift. A new RPLL is described in which the phase error is driven to zero using the quadrature signal derived from the SDFT. Further, the quadrature signal is reinforced by another cosine signal derived from a lookup table (LUT. The pulse frequency of the numerically controlled oscillator (NCO is extremely accurate, enabling fine tuning of the SDFT and RPLL also improves the lock time for the 50 Hz input signal to 0.04 s. The percentage phase error for the range 0.6 m to 6 m is about 0.2%. The VHDL codes generated for the various signal processing steps were downloaded into a Cyclone FPGA chip around which the ultrasonic ranger had been built.

  2. 基于COMSOL Multiphysics超声波电机的谐振特性分析%The Resonant Feature Analysis of Ultrasonic Motor Based on COMSOL Multiphysics

    Institute of Scientific and Technical Information of China (English)

    吕琼莹; 杨艳; 焦海坤; 张志杰

    2012-01-01

    基于COMSOL Multiphysics对超声波电机压电振子谐振特性进行了理论分析,建立了超声波电机压电振子的实体模型,仿真计算出了压电振子的谐振频率,确定超声波电动机的最佳工作频段,提出了电机与驱动电路匹配方法.试验结果表明:当对压电振子施加幅值为100 V的激励电压后,软件分析和数学计算基本一致,可见仿真分析方法的可行性,为研究超声波电机谐振特性提供了一种简便的计算方法.%The resonant feature of the piezoelectric resonator of ultrasonic motor is analyzed based on the COMSOL Multiphysics in this paper. The entity model of the piezoelectric resonator of ultrasonic motor has been established. The resonant frequency of the piezoelectric resonator was calculated by the simulation and the best operating frequency range of ultrasonic motor was determined. The matching method between the motor and the driving circuit was proposed. The test results showed that when an exciting voltage with the amplitude of 100 V was applied to the piezoelectric resonator, the software analysis results were basically consistent with the mathematical calculation thus indicated that the method of simulation analysis was feasible. This provides a simple calculation method for the study of the resonant feature of ultrasonic motor.

  3. Initial Rotor Position Estimation of Half-Wave Rectified Brushless Synchronous Motor

    Science.gov (United States)

    Abe, Takashi; Oyama, Jun; Higuchi, Tsuyoshi

    This paper presents an initial rotor position estimation of Half-Wave Rectified Brushless Synchronous Motor. In the previous paper, we proposed this motor as AC servo motor, which is based on the half-wave rectified brushless excitation principle. The basic principle of this estimation technique utilizes the dependence of inductance on the rotor position. The bias frequency component of half-Wave rectified brushless excitation is used to estimate the rotor position error. The magnetic pole is discriminated by the switching condition of the diode inserted into the rotor field winding. This estimation technique is confirmed by simulation include inverter circuit, control program and motor model. Finally, the effectiveness of the proposed estimation technique has been verified by experiments.

  4. Studying the effect of cracks on the ultrasonic wave propagation in a two dimensional gearbox finite element model

    Science.gov (United States)

    Ozevin, Didem; Fazel, Hossein; Cox, Justin; Hardman, William; Kessler, Seth S.; Timmons, Alan

    2014-04-01

    Gearbox components of aerospace structures are typically made of brittle materials with high fracture toughness, but susceptible to fatigue failure due to continuous cyclic loading. Structural Health Monitoring (SHM) methods are used to monitor the crack growth in gearbox components. Damage detection methodologies developed in laboratory-scale experiments may not represent the actual gearbox structural configuration, and are usually not applicable to real application as the vibration and wave properties depend on the material, structural layers and thicknesses. Also, the sensor types and locations are key factors for frequency content of ultrasonic waves, which are essential features for pattern recognition algorithm development in noisy environments. Therefore, a deterministic damage detection methodology that considers all the variables influencing the waveform signature should be considered in the preliminary computation before any experimental test matrix. In order to achieve this goal, we developed two dimensional finite element models of a gearbox cross section from front view and shaft section. The cross section model consists of steel revolving teeth, a thin layer of oil, and retention plate. An ultrasonic wave up to 1 MHz frequency is generated, and waveform histories along the gearbox are recorded. The received waveforms under pristine and cracked conditions are compared in order to analyze the crack influence on the wave propagation in gearbox, which can be utilized by both active and passive SHM methods.

  5. A Model for Measured Traveling Waves at End-Diastole in Human Heart Wall by Ultrasonic Imaging Method

    Science.gov (United States)

    Bekki, Naoaki; Shintani, Seine A.; Ishiwata, Shin'ichi; Kanai, Hiroshi

    2016-04-01

    We observe traveling waves, measured by the ultrasonic noninvasive imaging method, in a longitudinal beam direction from the apex to the base side on the interventricular septum (IVS) during the period from the end-diastole to the beginning of systole for a healthy human heart wall. We present a possible phenomenological model to explain part of one-dimensional cardiac behaviors for the observed traveling waves around the time of R-wave of echocardiography (ECG) in the human heart. Although the observed two-dimensional patterns of traveling waves are extremely complex and no one knows yet the exact solutions for the traveling homoclinic plane wave in the one-dimensional complex Ginzburg-Landau equation (CGLE), we numerically find that part of the one-dimensional homoclinic dynamics of the phase and amplitude patterns in the observed traveling waves is similar to that of the numerical homoclinic plane-wave solutions in the CGLE with periodic boundary condition in a certain parameter space. It is suggested that part of the cardiac dynamics of the traveling waves on the IVS can be qualitatively described by the CGLE model as a paradigm for understanding biophysical nonlinear phenomena.

  6. Development of an ultrasonic inspection robot using an electromagnetic acoustic transducer for a Lamb wave and an SH-plate wave.

    Science.gov (United States)

    Murayama, Riichi; Makiyama, Shunnichi; Kodama, Mitutoshi; Taniguchi, Yasutoshi

    2004-04-01

    For inspection of a storage tank and pipeline in service, the application of an automatic inspection system (nondestructive inspection robot) is desirable, because manual inspection is difficult to perfectly and exactly perform due to the enormous amount of inspection needed. However, an ultrasonic nondestructive inspection robot with a piezoelectric oscillator needs to touch only the material surface to be directly inspected using a coupling medium. That is, the material surface and the sensor must always be held by constant pressure in the vertical direction on the material side. Actually, it is difficult to overcome these problems; thus an ultrasonic inspection robot could not be widely applied. We then tried to develop an ultrasonic inspection robot with an electromagnetic acoustic transducer (EMAT) which did not require a coupling medium to inspect the circumferential pipe parts. We developed a special EMAT that could transmit and receive alternately a Lamb wave with high sensitivity and a SH-plate wave without influence by the welded part. The method by which the inspection robot turned around the direction of the steel pipe surroundings was executed by observing the tape pasted in the direction of the steel pipe surroundings with an installed CCD camera. In this report, the basic mechanism of this inspection robot and an examination of results are described.

  7. Modelling of the travelling wave piezoelectric motor stator: an integrated review and new perspective

    Directory of Open Access Journals (Sweden)

    Rodríguez, H.

    2004-06-01

    Full Text Available Articles from different areas which are closely related to the modelling of the stator of travelling wave ultrasonic motors (TWUMs are reviewed in this work. Thus, important issues relevant to this problem are identified from the areas of vibration of annular plates, laminated plate theories, and modelling of piezoelectric transducers. From this integrated point of view, it becomes clear that there are some very important issues yet to be addressed in the modelling of TWUMs. Firstly, the influence of material properties and stator dimensions on output efficiency, electromechanical coupling coefficients (EMCC and maximum output energy is to be investigated in more detail. Secondly, the modelling of the electric potential field (by explicitly including the charge equation for TWUMs seems to be a must for better prediction of displacements and electric fields close to the resonance, as suggested by some recent works [1]. Moreover, the improvement of current models by using shear deformation (or higher order laminated plate theories (LPTs in conjunction with approximated methods of solution are discussed. In addition to analytical models, those works using Finite Element and Finite difference Methods (FEM and FDM for the modelling and simulation of the TWUM stator dynamics are reviewed.

    En este trabajo se realiza una revisión de los trabajos de investigación realizados en diversas áreas sobre el modelado del estátor de los motores ultrasónicos de onda viajera (TWUMs. Entre los problemas relevantes que se han estudiado podemos citar la vibración de placas anulares, las teorías de placas laminadas y el modelado de transductores piezoeléctricos. A raíz de este punto de vista integral se hace manifiesto que todavía quedan asuntos importantes que estudiar en el modelado de los TWUMs. En primer lugar, la influencia de las propiedades del material y las dimensiones del estátor en la eficiencia del motor, los coeficientes de acoplamiento

  8. 基于LCC的超声波电动机驱动电路分析%Analysis of Driving Circuit for Ultrasonic Motor Based on LCC

    Institute of Scientific and Technical Information of China (English)

    傅平

    2012-01-01

    对基于LCC的超声波电动机驱动电路进行了初步的探讨.仿真和实验证明此电路的有效性.所提基于LCC的驱动电路为超声波电动机的驱动电路优化、性能提高和控制提供了理论基础,为电机控制性能的提升打下了基础.%A driving circuit based on LCC was presented in this paper for ultrasonic motor(USM) driving. Simulation and experiment results of the circuit were provided to demonstrate the effectiveness of the proposed circuit. The driving circuit based on LCC provides theoretical basis of optimization, performance and control method of ultrasonic motor drive.

  9. Fault Diagnosis of Ultrasonic Motor Based on Correlation Dimension%关联维数的超声波电机故障诊断

    Institute of Scientific and Technical Information of China (English)

    王理停; 黄宜坚

    2011-01-01

    利用关联维数分析方法对超声波电机进行故障诊断,并针对故障诊断的实际情况,建构特殊实验平台采集故障振动信号.通过互信息法及Cao方法来确定相空间重构的2个重要参数,然后计算超声波电机在不同故障状态下的关联维数.结果表明,不同故障状态产生机制不同,其关联维数也不同,关联维数可用于故障的特征提取.通过分析不同状态下超声波电机的关联维数,可以判断超声波电机是否出现故障.%The analysis method of correlation dimension is used in the fault diagnosis of ultrasonic motor, and a special experiment platform is built to collect fault vibration signal according to the actual conditions in fault diagnosis. The correlation dimensions of the different fault of ultrasonic motor were calculated through two important parameters of reconstruction of the phase space which were determined by the mutual information and Cao method. The results show that the mechanism of different faults for ultrasonic motor are related with their different correlation dimensions, so the correlation dimension can be used to extract the feature of the faults. By the analysis of the correlation dimension of different fault vibration signals, it can be judged whether there is a fault for ultrasonic motor or not.

  10. Increased range of ultrasonic guided wave testing of overhead transmission line cables using dispersion compensation.

    Science.gov (United States)

    Legg, Mathew; Yücel, Mehmet K; Kappatos, Vassilios; Selcuk, Cem; Gan, Tat-Hean

    2015-09-01

    Overhead Transmission Line (OVTL) cables can experience structural defects and are, therefore, inspected using Non-Destructive Testing (NDT) techniques. Ultrasonic Guided Waves (UGW) is one NDT technique that has been investigated for inspection of these cables. For practical use, it is desirable to be able to inspect as long a section of cable as possible from a single location. This paper investigates increasing the UGW inspection range on Aluminium Conductor Steel Reinforced (ACSR) cables by compensating for dispersion using dispersion curve data. For ACSR cables, it was considered to be difficult to obtain accurate dispersion curves using modelling due to the complex geometry and unknown coupling between wire strands. Group velocity dispersion curves were, therefore, measured experimentally on an untensioned, 26.5m long cable and a method of calculating theoretical dispersion curves was obtained. Attenuation and dispersion compensation were then performed for a broadband Maximum Length Sequence (MLS) excitation signal. An increase in the Signal to Noise Ratio (SNR) of about 4-8dB compared to that of the dispersed signal was obtained. However, the main benefit was the increased ability to resolve the individual echoes from the end of the cable and an introduced defect in the form of a cut, which was 7 to at least 13dB greater than that of the dispersed signal. Five echoes were able to be clearly detected using MLS excitation signal, indicating the potential for an inspection range of up to 130m in each direction. To the best of the authors knowledge, this is the longest inspection range for ACSR cables reported in the literature, where typically cables, which were only one or two meter long, have been investigated previously. Narrow band tone burst and Hann windowed tone burst excitation signal also showed increased SNR and ability to resolve closely spaced echoes. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. A New Omni-Directional EMAT for Ultrasonic Lamb Wave Tomography Imaging of Metallic Plate Defects

    Directory of Open Access Journals (Sweden)

    Songling Huang

    2014-02-01

    Full Text Available This paper proposes a new omni-directional electromagnetic acoustic transducer (EMAT for the ultrasonic Lamb wave (ULW tomography imaging (TI of defects in metallic plates. The proposed EMAT is composed of a permanent magnet and a coil with a contra-flexure structure. This new EMAT coil structure is used for omni-directional ULW transmission and reception and ULW TI for the first time. The theoretical background and the working principles of this EMAT are presented and analyzed. The experimental results of its use on a 3 mm thick aluminum plate indicate that the EMAT with a contra-flexure coil (CFC can transmit and receive a pure single A0 mode ULW with a high signal-to-noise ratio (SNR. Thus, the extraction of the projection data used for ULW TI may be performed accurately. The circumferential consistency of the projection data is only slightly influenced by the distortion of the eddy current field that is induced by the new CFC with an irregular shape. When the new EMAT array is used for ULW TI using the cross-hole method and SIRT arithmetic, a desirable imaging quality can be achieved, and the estimated size of an artificial corrosion defect agreed well with its actual value. The relation between the reconstruction resolution and the number of the new EMATs used is analyzed. More TI experiments are carried out when the aluminum plate defect is in two different locations relative to the EMAT array, for the further investigation of the performances of the new EMATs.

  12. A new omni-directional EMAT for ultrasonic Lamb wave tomography imaging of metallic plate defects.

    Science.gov (United States)

    Huang, Songling; Wei, Zheng; Zhao, Wei; Wang, Shen

    2014-02-20

    This paper proposes a new omni-directional electromagnetic acoustic transducer (EMAT) for the ultrasonic Lamb wave (ULW) tomography imaging (TI) of defects in metallic plates. The proposed EMAT is composed of a permanent magnet and a coil with a contra-flexure structure. This new EMAT coil structure is used for omni-directional ULW transmission and reception and ULW TI for the first time. The theoretical background and the working principles of this EMAT are presented and analyzed. The experimental results of its use on a 3 mm thick aluminum plate indicate that the EMAT with a contra-flexure coil (CFC) can transmit and receive a pure single A0 mode ULW with a high signal-to-noise ratio (SNR). Thus, the extraction of the projection data used for ULW TI may be performed accurately. The circumferential consistency of the projection data is only slightly influenced by the distortion of the eddy current field that is induced by the new CFC with an irregular shape. When the new EMAT array is used for ULW TI using the cross-hole method and SIRT arithmetic, a desirable imaging quality can be achieved, and the estimated size of an artificial corrosion defect agreed well with its actual value. The relation between the reconstruction resolution and the number of the new EMATs used is analyzed. More TI experiments are carried out when the aluminum plate defect is in two different locations relative to the EMAT array, for the further investigation of the performances of the new EMATs.

  13. Testing and Analyzing System of Stator of Ultrasonic Motor%超声电机的定子振动测试与分析

    Institute of Scientific and Technical Information of China (English)

    武威

    2013-01-01

    Ultrasonic Motor (USM) is a new kind of motor which is being developed in the recent twenty years. A testing platform for USM is established, based on virtual instruments, sensors and computer. Through digital filtering, processing and frequency domain analysis to achieve to measure and analysis the vibration signal of important components of Ultrasonic Motor-stator. Hardware, software function models, test principle and experiment are discussed in details in the article. The experiment proved that the system is simple and stable.%超声电机(Ultrasonic Motor,简称USM)是近二十年发展起来的一种全新原理的电机。基于虚拟仪器、硬件传感器及计算机搭建了超声电机的测试平台,通过数字滤波等处理和频域分析,实现对超声电机的重要元件(定子)振动信号的检测与分析。从系统硬件选择、软件设计及试验测试几个方面进行了详细论述。经试验证明,该系统结构简单,可以稳定运行。

  14. MIT Model Reference Adaptive Speed Control of Ultrasonic Motor%超声波电动机MIT模型参考自适应转速控制

    Institute of Scientific and Technical Information of China (English)

    沈晓茜; 史敬灼

    2013-01-01

    The cost of ultrasonic motor control system including the driving circuit can be reduced by using a relatively simple motion control algorithm,so as to promote the mass production of ultrasonic motor.Aiming at this purpose,a simple model reference adaptive control strategy used to control speed of ultrasonic motor was proposed.This strategy has a small amount of calculation and moderate capacity of adaptive.Therefore,the performance-to-price ratio of the system can be increased.%采用相对简单的运动控制算法,有助于降低包含驱动控制电路在内的超声波电动机系统的成本,从而推动其产业化.基于这一目的,给出一种模型参考自适应控制策略用于超声波电动机转速控制.该策略计算量小,并具有一定程度的自适应能力,提高了系统性价比.

  15. Wave propagation in a viscous fluid with a pipeline shear mean flow and application for ultrasonic flow meter

    Science.gov (United States)

    Chen, Yong; Huang, Yiyong; Chen, Xiaoqian

    2013-11-01

    This paper deals with the problem of wave propagation in a compressible viscous fluid confined by a rigid-walled circular pipeline in the presence of a shear mean flow. On the assumption of isentropic and axisymmetric wave propagation, the convected acoustic equations are mathematically deduced from the conservations of continuity and momentum, leading to a set of coupled second-order differential equations with respect of the acoustic pressure and velocity components in radial and axial directions. A solution based on the Fourier-Bessel theory, which is complete and orthogonal in Lebesgue space, is introduced to transform the differential equations to an infinite set of homogeneous algebraic equations, thus the wave number can be calculated due to the existence condition of a non-trivial solution. After the discussion of the method's convergence, the cut-off frequency of the wave mode is theoretically analyzed. Furthermore, wave attenuation of the first four wave modes due to fluid viscosity is numerically studied in the presence of the laminar and turbulent flow profiles. Meanwhile, the measurement performance of an ultrasonic flow meter based on the difference of downstream and upstream wave propagations is parametrically addressed.

  16. Measurement of absolute displacement-amplitude of ultrasonic wave using piezo-electric detection method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seong Hyun; Kim, Jong Beom; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

    2017-02-15

    A nonlinear ultrasonic parameter is defined by the ratio of displacement amplitude of the fundamental frequency component to that of the second-order harmonic frequency component. In this study, the ultrasonic displacement amplitude of an SUS316 specimen was measured via a piezo-electric-based method to identify the validity of piezo-electric detection method. For comparison, the ultrasonic displacement was also determined via a laser-based Fabry-Pérot interferometer. The experimental results for both measurements were in good agreement. Additionally, the stability of the repeated test results from the piezo-electric method exceeded that of the laser-interferometric method. This result indicated that the piezo-electric detection method can be utilized to measure a nonlinear ultrasonic parameter due to its excellent stability although it involves a complicated process.

  17. Design of Miniature Cylindrical Ultrasonic Motor with Longitudinal Bending Compound Excitation%微小型纵弯复合激励式圆筒超声电机的设计

    Institute of Scientific and Technical Information of China (English)

    宋起超; 周真

    2013-01-01

    为了有效提高超声电机的机械输出性能,研制了一种微小型贴片式纵弯复合激励式圆筒型行波超声电机。该电机由圆筒和一个纵弯复合换能器组成,换能器位于圆筒的外侧壁上,换能器由一对弯振压电陶瓷片、一对纵振压电陶瓷片和前端为变幅杆的长方形铝块组成。对电机的工作原理进行了分析,利用有限元方法对电机进行了设计与仿真,实现了电机两个基本振动模态特征频率的简并。对振动特性进行了测试,测试结果与有限元分析结果吻合良好。测试结果表明,换能器的纵振、弯振和圆筒弯振模态之间均实现了很好的匹配。%In order to improve the mechanical performance of ultrasonic motor, a miniature patch cylindrical traveling wave ultrasonic motor using longitudinal bending composite excitation is proposed. The motor is composed of a cylinder and a longitudinal-bending transducer located on the lateral wall of the cylinder. The transducer is made up of a pair of bending vibration piezoelectric ceramic plates, a pair of longitudinal vibration piezoelectric ceramic plates and a rectangular aluminum piece whose front end is the amplitude transformer. The motor is designed and simulated using finite element method based on the analysis of the working principle of the motor, which realizes frequency degeneracy of the two basic vibration modes of the motor. The vibration characteristics are tested. The test results well agree with the results of finite element method, and show that longitudinal vibration mode, bending vibration mode and cylindrical bending vibration mode match well.

  18. A hybrid ultrasonic motor and electrorheological fluid clutch actuator for force-feedback in MRI/fMRI.

    Science.gov (United States)

    Chapuis, Dominique; Gassert, Roger; Burdet, Etienne; Bleuler, Hannes

    2008-01-01

    This paper presents a safe, electrically powered MR-compatible actuator with a large range of output impedance, which can be used at the entry of the scanner bore. This actuator is composed of an ultrasonic motor (USM) and a torque-controlled electrorheological fluid clutch which modulates the output torque of the USM. This paper describes the developments on the electrorheological fluid (ERF) clutch and its high voltage driver. The performances of the ERF brake constituting the clutch are evaluated, and its torque range is adapted using an epicyclic differential. The transmissible torque of the ERF clutch, i.e., the maximum system output torque, is 94.4 mNm and its drag torque is 2.6 mNm. The MR compatibility of the complete hybrid actuator is shown in extensive tests including subtraction of images and comparison of signal-to-noise ratios in powered and unpowered conditions. This novel MR-compatible actuator may be used to study the neural control of the hand.

  19. Linear Ultrasonic Motor Clamped by Flexible Hinge%柔性铰链结构夹持的直线型超声电机

    Institute of Scientific and Technical Information of China (English)

    于会民; 陈乾伟; 黄卫清

    2011-01-01

    分析了直线型超声电机理想夹持模型与实际夹持模型的差别,并提出了实际夹持模型应满足的要求.针对南京航空航天大学精密驱动研究所研制的双变幅杆V型直线超声电机提出了基于柔性铰链结构的夹持方案,此方案显著地提高了电机的机械性能及稳定性,电机的最大输出力达28.8 N.通过实验研究了不同弹性元件对直线电机输出性能的影响,并对直线电机所使用的弹性元件提出了要求.%The difference between the ideal clamping model and the actual clamping model of linear ultrasonic motor was analyzed in this paper, and the requirements which the actual clamping model should meet were proposed. A new attachment scheme of flexible hinge for V-shape linear ultrasonic motor based on amplifier pole was proposed, and the linear ultrasonic motor was developed by precision driving laboratory Nanjing University of Aeronautics and Astronautics. The scheme can improve the mechanical properties and stability of linear motor significantly, its maximum output force was up to 28.8 N. The effect of different elastic component on the out performance of linear motor was studied by experiment, and the requirements of elastic components were proposed.

  20. Influence of timing variability between motor unit potentials on M-wave characteristics.

    Science.gov (United States)

    Rodriguez-Falces, Javier; Malanda, Armando; Latasa, Iban; Lavilla-Oiz, Ana; Navallas, Javier

    2016-10-01

    The transient enlargement of the compound muscle action potential (M wave) after a conditioning contraction is referred to as potentiation. It has been recently shown that the potentiation of the first and second phases of a monopolar M wave differed drastically; namely, the first phase remained largely unchanged, whereas the second phase underwent a marked enlargement and shortening. This dissimilar potentiation of the first and second phases has been suggested to be attributed to a transient increase in conduction velocity after the contraction. Here, we present a series of simulations to test if changes in the timing variability between motor unit potentials (MUPs) can be responsible for the unequal potentiation (and shortening) of the first and the second M-wave phases. We found that an increase in the mean motor unit conduction velocity resulted in a marked enlargement and narrowing of both the first and second M-wave phases. The enlargement of the first phase caused by a global increase in motor unit conduction velocities was apparent even for the electrode located over the innervation zone and became more pronounced with increasing distance to the innervation zone, whereas the potentiation of the second phase was largely independent of electrode position. Our simulations indicate that it is unlikely that an increase in motor unit conduction velocities (accompanied or not by changes in their distribution) could account for the experimental observation that only the second phase of a monopolar M wave, but not the first, is enlarged after a brief contraction. However, the combination of an increase in the motor unit conduction velocities and a spreading of the motor unit activation times could potentially explain the asymmetric potentiation of the M-wave phases.

  1. Hybrid Modelling of a Traveling Wave Piezoelectric Motor

    DEFF Research Database (Denmark)

    El, Ghouti N.

    torque at low speed, quiet operation (ultrasonic), simple structure, compactness in size and no electromagnetic interferences. However, the mathematical model of the PEM is complex and difficult to derive due to its driving principle based on high-frequency mechanical vibrations and frictional force...... the performance characteristics of the PEM under various working conditions. The main objective of this PhD project is to derive a suitable model for investigating some nonlinear control strategies in a simulated environment. Most of the existing modeling approaches are inappropriate for the control community due......) and finally the basic laws of dynamics. In order to overcome some of the drawbacks of the existing methods, and thereby meet the needs of the control community, three main approaches are considered in this modeling task. First, the equivalent circuit method is investigated in order to derive a lumped model...

  2. Ultrasonic neuromodulation

    Science.gov (United States)

    Naor, Omer; Krupa, Steve; Shoham, Shy

    2016-06-01

    Ultrasonic waves can be non-invasively steered and focused into mm-scale regions across the human body and brain, and their application in generating controlled artificial modulation of neuronal activity could therefore potentially have profound implications for neural science and engineering. Ultrasonic neuro-modulation phenomena were experimentally observed and studied for nearly a century, with recent discoveries on direct neural excitation and suppression sparking a new wave of investigations in models ranging from rodents to humans. In this paper we review the physics, engineering and scientific aspects of ultrasonic fields, their control in both space and time, and their effect on neuronal activity, including a survey of both the field’s foundational history and of recent findings. We describe key constraints encountered in this field, as well as key engineering systems developed to surmount them. In closing, the state of the art is discussed, with an emphasis on emerging research and clinical directions.

  3. Ultrasonic guided wave characterization and damage detection in foam-core sandwich panel using PWAS and LDV

    Science.gov (United States)

    Chakraborty, Nibir; Roy Mahapatra, D.; Srinivasan, Gopalakrishnan

    2012-04-01

    Lamb wave type guided wave propagation in foam core sandwich structures and detectability of damages using spectral analysis method are reported in this paper. An experimental study supported by theoretical evaluation of the guided wave characteristics is presented here that shows the applicability of Lamb wave type guided ultrasonic wave for detection of damage in foam core sandwich structures. Sandwich beam specimens were fabricated with 10 mm thick foam core and 0.3 mm thick aluminum face sheets. Thin piezoelectric patch actuators and sensors are used to excite and sense guided wave. Group velocity dispersion curves and frequency response of sensed signal are obtained experimentally. The nature of damping present in the sandwich panel is monitored by measuring the sensor signal amplitude at various different distances measured from the center of the linear phased array. Delaminations of increasing width are created and detected experimentally by pitch-catch interrogation with guided waves and wavelet transform of the sensed signal. Signal amplitudes are analyzed for various different sizes of damages to differentiate the damage size/severity. A sandwich panel is also fabricated with a planer dimension of 600 mm x 400 mm. Release film delamination is introduced during fabrication. Non-contact Laser Doppler Vibrometer (LDV) is used to scan the panel while exciting with a surface bonded piezoelectric actuator. Presence of damage is confirmed by the reflected wave fringe pattern obtained from the LDV scan. With this approach it is possible to locate and monitor the damages by tracking the wave packets scattered from the damages.

  4. Experimental testing and research of the ultrasonic motor performance%超声电机性能的实验测试研究

    Institute of Scientific and Technical Information of China (English)

    蔡卫刚

    2012-01-01

    The ultrasonic motor is a new concept, new motor using piezoelectric materials converse piezoelectric effect, make the stator surface of certain track, then the sub-micrometer range by friction coupling vibration of rotor vibration energy will be converted or slide block or translational motion (macro), this paper explores the energy to stress at different under the action of the frequency, phase of motor speed. The study of ultrasonic motor speed control provides theory basis.%超声电机是一种全新概念的新型电机,它利用压电材料的逆压电效应,使定子表面产生一定轨迹的微米量级的振动,进而通过摩擦耦合将振动动能转换成转子或滑块的宏观运动(转动或平动)动能,文章探究了在不同予应力的作用下电机的频率、相位对转速的影响。该研究为超声电机转速的控制提供了理论依据。

  5. A cylindrical micro-ultrasonic motor (stator transducer size: 1.4 mm in diameter and 5.0 mm long)

    Science.gov (United States)

    Morita; Kurosawa; Higuchi

    2000-03-01

    Ultrasonic motors are suitable for a micro-actuator because of a direct drive, no brake and their simple construction. In order to fabricate micro-ultrasonic motors, a piezoelectric thin film is essential. In this study, a hydrothermal method was adopted to deposit a PZT thin film. The dimensions of the stator transducer were: outer diameter, 1.4 mm; inner diameter, 1.2 mm; and length, 5.0 mm. The resonance frequency of the stator transducer was 227 kHz, and the vibration amplitude was 58 nmp-p at an input voltage of 4.0 Vp-p. The maximum revolution speed was 680 rpm, and the maximum starting torque was 0.67 microNm. The experimental conditions were 20 Vp-p and 5.3 mN pre-load. The motor property versus scale was investigated using an equivalent circuit. The calculated results indicated that the output torque of the 100 microns diameter motor was 27 nNm.

  6. Effect of motor imagery and voluntary muscle contraction on the F wave.

    Science.gov (United States)

    Hara, Motohiko; Kimura, Jun; Walker, D David; Taniguchi, Shinichirou; Ichikawa, Hiroo; Fujisawa, Reiko; Shimizu, Hiroshi; Abe, Tatsuya; Yamada, Thoru; Kayamori, Ryoji; Mizutani, Tomohiko

    2010-08-01

    We tested the validity of instructing patients to minimally contract the muscle to facilitate F-wave recording in clinical practice. In 12 healthy subjects, F waves were recorded from the first dorsal interosseous muscle at rest, during motor imagery, and at up to 30% of the maximal voluntary contraction (MVC). F-wave persistence increased significantly from 32.5 +/- 11.9% (mean +/- SD) at rest to 58.3 +/- 15.2% during motor imagery and 90.0 +/- 8.7% during 3% MVC. It then remained the same during stepwise changes to and from 30% MVC before decreasing significantly from 80.8 +/- 18.5% during 3% MVC to 48.7 +/- 23.8% during motor imagery and 27.0 +/- 16.0% at rest. The trial average of F-wave amplitude showed a similar pattern of facilitation. Motor imagery enhances F-wave persistence and amplitude, which further increase with a slight muscle contraction and show no additional change with a stronger effort.

  7. Influence of ultrasonic waves in the reduction of nitrate to nitrite by hydrazine-Cu(II).

    Science.gov (United States)

    Silva, Luciana A; Korn, Mauro; de Andrade, Jailson B

    2007-02-01

    Colorimetric methods are still important for determining nitrate and nitrite. A critical step in the use of these methods to determine nitrate in low concentrations is the reaction time required to totally reduce nitrate to nitrite, i.e., 24h in the dark. This work involved a study of the influence of ultrasonic irradiation on the nitrate reduction reaction by hydrazine. Our findings indicated that ultrasonic irradiation, associated with copper(II) ion as a catalyst, increased the redox reaction rate, decreasing the reaction time to about 10min when the power of the ultrasonic irradiation was set in 14.0357W. The strong influence of the ultrasonic irradiation in the reduction reaction rates can be sustained by an excellent linear correlation (R(2)=0.9993) between the kinetic constants and ultrasonic powers. Nitrate conversion also increased from 68% to 98% at the latter conditions. It thus become clear that high intensity ultrasound is very beneficial for this reduction reaction to proceed in good yield and in short reaction time in comparison to its silent reaction.

  8. 2D numerical modeling of ultrasonic wave propagation in concrete: A parameterization study in a multiple-scattering medium

    Science.gov (United States)

    Yu, Ting; Chaix, Jean-François; Komatitsch, Dimitri; Garnier, Vincent; Audibert, Lorenzo; Henault, Jean-Marie

    2017-02-01

    Multiple scattering is important when ultrasounds propagate in a heterogeneous medium such as concrete, the scatterer size of which is in the order of the wavelength. The aim of this work is to build a 2D numerical model of ultrasonic wave propagation integrating the multiple scattering phenomena in SPECFEM software. The coherent field of multiple scattering could be obtained by averaging numerical wave fields, and it is used to determine the effective phase velocity and attenuation corresponding to an equivalent homogeneous medium. After the creation of numerical model under several assumptions, its validation is completed in a case of scattering by one cylinder through the comparison with analytical solution. Two cases of multiple scattering by a set of cylinders at different concentrations are simulated to perform a parametric study (of frequency, scatterer concentration, scatterer size). The effective properties are compared with the predictions of Waterman-Truell model as well, to verify its validity.

  9. Microfluidic electro-sonoporation: a multi-modal cell poration methodology through simultaneous application of electric field and ultrasonic wave.

    Science.gov (United States)

    Longsine-Parker, Whitney; Wang, Han; Koo, Chiwan; Kim, Jeongyun; Kim, Beomjoon; Jayaraman, Arul; Han, Arum

    2013-06-07

    A microfluidic device that simultaneously applies the conditions required for microelectroporation and microsonoporation in a flow-through scheme toward high-efficiency and high-throughput molecular delivery into mammalian cells is presented. This multi-modal poration microdevice using simultaneous application of electric field and ultrasonic wave was realized by a three-dimensional (3D) microelectrode scheme where the electrodes function as both electroporation electrodes and cell flow channel so that acoustic wave can be applied perpendicular to the electric field simultaneously to cells flowing through the microfluidic channel. This 3D microelectrode configuration also allows a uniform electric field to be applied while making the device compatible with fluorescent microscopy. It is hypothesized that the simultaneous application of two different fields (electric field and acoustic wave) in perpendicular directions allows formation of transient pores along two axes of the cell membrane at reduced poration intensities, hence maximizing the delivery efficiency while minimizing cell death. The microfluidic electro-sonoporation system was characterized by delivering small molecules into mammalian cells, and showed average poration efficiency of 95.6% and cell viability of 97.3%. This proof of concept result shows that by combining electroporation and sonoporation together, significant improvement in molecule delivery efficiency could be achieved while maintaining high cell viability compared to electroporation or sonoporation alone. The microfluidic electro-sonoporation device presented here is, to the best of our knowledge, the first multi-modal cell poration device using simultaneous application of electric field and ultrasonic wave. This new multi-modal cell poration strategy and system is expected to have broad applications in delivery of small molecule therapeutics and ultimately in large molecule delivery such as gene transfection applications where high

  10. Giant repeater F-wave in patients with anterior horn cell disorders. Role of motor unit size.

    Science.gov (United States)

    Ibrahim, I K; el-Abd, M A

    1997-01-01

    Conventional F-wave responses as well as single motor unit F-wave responses together with the volitionally recruited motor unit action potentials (MUAP) were studied in hand and feet muscles of 10 healthy subjects and 32 patients with anterior horn cell disorders. The amplitude of the largest F-wave (Fl) was significantly greater in the affected patients compared with healthy subjects. Giant repeater F-wave responses "up to 4 mV" were recorded in muscles having volitionally recruited giant MUAPs. Although, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs was significantly decreased in amyotrophic lateral sclerosis patients, the group mean percentage of motor unit F-wave responses per stimulation in all tested orthodromic MUAPs that gave motor unit F-wave response was significantly increased compared with healthy subjects. The responding orthodromic MUAP gave identical motor unit F-wave response, even for complex polyphasic units. Enhanced monosynaptic (H-) reflex, proximal axon reflex (A-wave), and repetitive muscle response as possible explanations for the giant F-wave responses could be discounted. The electrophysiologic behavior of the giant late responses described here fits well with the criteria of F-waves modulated by newly formed distal (and or proximal) axonal branching.

  11. Development and existing problems of longitudinal and torsional hybrid type ultrasonic motors%纵扭型超声电机的研发进展与现存问题

    Institute of Scientific and Technical Information of China (English)

    陶征; 赵淳生

    2011-01-01

    The ultrasonic motors are high products which have the fire-new structure based on fire-new theory. The longitudinal-torsional ultrasonic motors have become an research issue because they have larger momental and better controllability. The research of the longitudinal-torsional ultrasonic motors begin from the compound longitudinal-torsional ultrasonic motors at the end of 1980s and developed into the modal transformation ultrasonic motor,one of the most representative motors. Though they develped quickly, the research history of longitudinal-torsional ultrasonic motors is shorter. So they are not ripe in theory and technology. Problems of theory, friction and wear, preloading spring performance and motor structure development will become the research emphasis in the future.%超声电机是基于全新原理具有全新结构的高技术电机产品,而纵扭型超声电机更因其具有更大的扭矩、更好的可控性而备受业界重视从而成为研究热点.从1980年代末的纵扭复合型超声电机到最具代表性的模态转换型超声电机,国内外纵扭型超声电机的研制虽不断推陈出新,但由于研究历史尚短,理论上、技术上尚不成熟,其所面对的理论问题、摩擦磨损问题、预压力弹簧性能问题、电机结构改进问题亟待解决.

  12. The Use of Ultrasonic Seismic Wave Attenuation (Q) for Better Subsurface Imaging, Energy Exploration, and Tracking of Sequestrated Carbon Dioxide

    Science.gov (United States)

    Delaney, D.; Purcell, C. C.; Mur, A. J.; Haljasmaa, I.; Soong, Y.; Harbert, W.

    2012-12-01

    Parameters related to seismic and ultrasonic elastic waves traveling through a porous rock material with compliant pores, cracks and isometric pores are subject to variations which are dependent on the physical properties of the rock such as density, porosity, permeability, frame work moduli, fluid moduli, micro structural variation, and effective pressure. Our goal is to understand these variations through experiments completed using Berea sandstone, rhyolites, coal, and carbonate samples. Understanding these lithologies are relevant to enhanced oil recovery, enhanced geothermal, and CO2 storage activities. Working in the COREFLOW laboratory at the National Energy Technology Laboratory (NETL) of the United States Department of Energy (DOE) we performed several experiments on these rock types with various different pore filling fluids, effective pressures, and temperatures. We measured P, S1 and S2 ultrasonic velocities using an New England Research (NER) Autolab 1500 device and calculated the lame parameters (Bulk modulus (K), Young's modulus (E), Lamè's first parameter (λ), Shear modulus (G), Poisson's ratio ( ), P-wave modulus (M)). Using an aluminum reference core and the P, S1, and S2 ultrasonic waveform data collected, we employed the spectral ratio method to estimate Q. This method uses the ratio of the amplitude-frequency spectrum (obtained via fast Fourier Transform and processed using Matlab) of the rock core compared with the amplitude-frequency spectrum of the aluminum reference core to calculate the quality factor (Q). The quality factor is a dimensionless value that represents the attenuation of a seismic wave as it travels through a rock. Seismic attenuation is dependent on wave velocity, the path length or time the wave is in the rock, and of course the physical properties of the rock through which the wave travels. Effective pressures used in our experiments varied between 0.01 MPa and 50 MPa and temperatures varied between 21 C to 80 C which

  13. 纵振换能器式圆筒型超声电机振动特性的研究%Research on the vibration characteristics of cylindrical type ultrasonic motor using longitudinal vibration transducers

    Institute of Scientific and Technical Information of China (English)

    刘英想; 陈维山; 杨小辉; 刘军考

    2012-01-01

    In a previous research, the authors have presented and developed a cylindrical type ultrasonic motor using longitudinal vibration transducers. Four uniform longitudinal vibration transducers are adopted in this motor to excite a bending vibration traveling wave in a cylinder with teeth. The simulation and experiment results of this motor indicate that the vibration state of the transducer is not single longitudinal vibration, but longitudinal and bending coupled vibration. This study focuses the research on the vibration state of the transducer in the previous motor. Firstly, the reason for the bending vibration of the transducer is given. Then, the effect of the coupling bending vibration on the electromechanical coupling factor of the motor and the distortion of traveling wave are studied. The study results state that the coupling bending vibration of the transducer can make the resonance frequency of the stator deviate from the resonance of the transducer and cause a distortion of traveling wave in the cylinder. Finally, new mode to excite the radial bending vibration of a cylinder by using the bending vibration of a transducer is presented.%以纵振夹心换能器式圆筒型超声电机为研究对象,对换能器的振动状态进行了分析,给出了换能器弯曲振动的产生原因;研究了耦生弯振对电机机电耦合系数以及圆筒中弯振行波质量所带来的影响,耦生弯振的存在使得定子模态特征频率偏离换能器谐振频率,并使得定子圆筒中的弯振行波产生了畸变.最后,提出一种采用换能器弯振激励圆筒径向弯振的模态组合方式.

  14. Structural Diagnostics of CFRP Composite Aircraft Components by Ultrasonic Guided Waves and Built-In Piezoelectric Transducers

    Energy Technology Data Exchange (ETDEWEB)

    Matt, Howard M. [Univ. of California, San Diego, CA (United States)

    2006-01-01

    To monitor in-flight damage and reduce life-cycle costs associated with CFRP composite aircraft, an autonomous built-in structural health monitoring (SHM) system is preferred over conventional maintenance routines and schedules. This thesis investigates the use of ultrasonic guided waves and piezoelectric transducers for the identification and localization of damage/defects occurring within critical components of CFRP composite aircraft wings, mainly the wing skin-to-spar joints. The guided wave approach for structural diagnostics was demonstrated by the dual application of active and passive monitoring techniques. For active interrogation, the guided wave propagation problem was initially studied numerically by a semi-analytical finite element method, which accounts for viscoelastic damping, in order to identify ideal mode-frequency combinations sensitive to damage occurring within CFRP bonded joints. Active guided wave tests across three representative wing skin-to-spar joints at ambient temperature were then conducted using attached Macro Fiber Composite (MFC) transducers. Results from these experiments demonstrate the importance of intelligent feature extraction for improving the sensitivity to damage. To address the widely neglected effects of temperature on guided wave base damage identification, analytical and experimental analyses were performed to characterize the influence of temperature on guided wave signal features. In addition, statistically-robust detection of simulated damage in a CFRP bonded joint was successfully achieved under changing temperature conditions through a dimensionally-low, multivariate statistical outlier analysis. The response of piezoceramic patches and MFC transducers to ultrasonic Rayleigh and Lamb wave fields was analytically derived and experimentally validated. This theory is useful for designing sensors which possess optimal sensitivity toward a given mode-frequency combination or for predicting the frequency dependent

  15. 模态转换型超声波电机的驱动机理与研究进展%Driving Principle and Recent Development of Modal Conversion Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    陈建毅; 郑祝堂; 陈方辉

    2013-01-01

    模态转换型超声波电机因具有结构简单且功率输出大的特点而备受关注.本文分析了不同类型的模态转换形式超声波电机的驱动机理,详细介绍当前国内外有关的研究情况和研究进展,并指出该类型超声波电机是今后大力矩超声波电机的重要发展方向.%The modal conversion ultrasonic motor is attractive for its simple structure and large torque.In this paper,the driving principles of ultrasonic motors with different modal conversion types were analyzed.The recent developments and research progress of the modal conversion ultrasonic motor both at home and abroad were introduced.Pointed out that this kind of ultrasonic motor would be come an important one of the ultrasonic motors with large torque.

  16. KAJIAN SIFAT AKUSTIK BUAH MANGGIS(Gracinia mangostana L DENGAN MENGGUNAKAN GELOMBANG ULTRASONIK [Acoustic Study Of Mangosteene (Gracinia mangostana L By Using Ultrasonic Wave

    Directory of Open Access Journals (Sweden)

    Jajang juansah 1

    2007-06-01

    Full Text Available The wave used to study the acoustic properties of mangosteen is ultrasonic wave. Ultrasonic wave with frequency of 50 KHz was used to determine acoustic properties of mangosteen. The main wave properties were the attenuation, impedance of acoustic and acoustic velocity at mangosteen. Others have been evaluated were the correlation of attenuation and acoustic velocity at parts of mangosteen with its intact mangosteen. The acoustic parameters were related to the physic-chemical parameters of the fruit (TDS and hardness. This relationship was used to study mangosteen properties and quality. Because of mangosteen structure and it’s pores (saw with low density, acoustic wave in manggosteen have low amplitude signal. It was saw with spectrum and FFT signal mangosteen and reference medium / air (1.4:2.3.The fruit with increasing maturity mount (from color index 2 to 5 will experience hardness degradation, improvement of TDS, which are related to degradation of acoustic attenuation, improvement of acoustic speed and impedance. Multiple regression method was used to get empiric equation of wave in mixture of flesh-seed, husk and mangosteen (parts of mangosteen with its intact mangosteen. That saw in equation 1 and 2. the velocity and attenuation of ultrasonic wave in mixture of flesh – seed have higher effect equation on mangosteen than husk. It means that acoustic properties of mixture of flesh – seed has more contribution than husk.

  17. Ultrasonic Guided Wave Technology for Non-Invasive Assessment of Corrosion-Induced Damage in Piping for Pollution Prevention in DOD Fuel Storage Facilities

    Science.gov (United States)

    2011-08-01

    put on in a three step process per manufacturer’s recommendation. A relatively thin coat of bitumen mastic was applied to the entire pipe surface...Figure. Summary of Ultrasonic Guided Wave Results The Signal peak height from each data trace was extracted and then plotted versus percent CSAL in

  18. Self-organization of waves and pulse trains by molecular motors in cellular protrusions.

    Science.gov (United States)

    Yochelis, A; Ebrahim, S; Millis, B; Cui, R; Kachar, B; Naoz, M; Gov, N S

    2015-09-03

    Actin-based cellular protrusions are an ubiquitous feature of cells, performing a variety of critical functions ranging from cell-cell communication to cell motility. The formation and maintenance of these protrusions relies on the transport of proteins via myosin motors, to the protrusion tip. While tip-directed motion leads to accumulation of motors (and their molecular cargo) at the protrusion tip, it is observed that motors also form rearward moving, periodic and isolated aggregates. The origins and mechanisms of these aggregates, and whether they are important for the recycling of motors, remain open puzzles. Motivated by novel myosin-XV experiments, a mass conserving reaction-diffusion-advection model is proposed. The model incorporates a non-linear cooperative interaction between motors, which converts them between an active and an inactive state. Specifically, the type of aggregate formed (traveling waves or pulse-trains) is linked to the kinetics of motors at the protrusion tip which is introduced by a boundary condition. These pattern selection mechanisms are found not only to qualitatively agree with empirical observations but open new vistas to the transport phenomena by molecular motors in general.

  19. Interdigital Piezopolymer Transducers for Time of Flight Measurements with Ultrasonic Lamb Waves on Carbon-Epoxy Composites under Pure Bending Stress

    OpenAIRE

    Andrea Bulletti; Lorenzo Capineri

    2015-01-01

    Interdigital transducers fabricated with piezopolymer film have been realized to excite ultrasonic Lamb waves in a composite laminate subjected to pure bending stresses. Lamb waves were generated and detected in a cross-ply [0°/90°] 4 mm thick carbon-fiber composite, by using two interdigital transducers in pitch-catch configuration. We demonstrate that the choice of the piezopolymer transducer technology is suitable for this type of investigation and the advantages of the proposed transducer...

  20. A driving-controlling system of ultrasonic motor based on LPC2124%基于LPC2124的超声波电机驱动控制系统

    Institute of Scientific and Technical Information of China (English)

    陈俊; 张德; 赵先锋; 李寅鑫

    2011-01-01

    For the special driving and controlling features of traveling-wave type ultrasonic motor,to facilitate motor's testing, to detect the speed or position of motor, to sense the temperature when first driving the motor, this paper designed a system based on LPC2124.A traditional push-pull circuit amplified power and series inductor resonated with motor. LPC2124's pulsewidth modulator and A/D converter with an adjustable resistor could modulate the frequency of PWM real time. Hall sensor ATS6421.SH detected the speed or position with a ring gear fixed on the rotor.LM75 measured the environment temperature,and LPC2124 generated PWM signals according to the temperature,especially when first driving the motor. The experiment results show that the system could successfully measure the temperature,steadily and reliably drive motor,and detect speed or position singal.%针对行波型超声波电机的驱动控制特性,为方便电机调试,实现电机的转速或位置信号检测,检测电机首次启动时的环境温度,设计了一款基于LPC2124的驱动控制系统.来用传统的推挽电路实现功率放大,串联电感进行谐振匹配.运用LPC2124内置的脉宽调制器和A/D转换器,外加微调电阻,可实时调节PWM频率,从而方便电机的调试.霍尔传感器ATS642LSH结合固定在电机转子上的环形齿轮,检测电机转速或位置.采用LM75温度传感器,检测坏境温度,给电机的首次启动提供一个参考温度.试验表明,系统能顺利检测环境温度,能稳定、可靠地驱动电机工作,同时检测电机的转速或位置信号.

  1. A Versatile Inspection System for Pipe Structure Using Ultrasonic Waves Propagation Imager

    Science.gov (United States)

    Truong, T. C.; Lee, J. R.

    2015-07-01

    Pipe structure is vulnerable to many types of damage, such as flow-accelerated corrosion, crack, and in the case of multi-layers pipe, debonding damage. A versatile damage inspection system is needed, where it must be easily used for variety types of pipeline, must have the capability to detect many types of damage, as well as must be able to carry out inspection in the working condition of the pipe system. In this paper, we present the Ultrasonic Propagation Imager (UPI) that demonstrated to meet those demands. The UPI system consists of a high speed Q-switched laser, a high speed scanning mirror, a DAQ system, and a changeable sensing system depends on applications. Advanced signal processing using ultrasonic wavenumber imaging algorithm and energy mapping were applied for damage detection of the pipe structures.

  2. Vibration characteristics of aluminum surface subjected to ultrasonic waves and their effect on wetting behavior of solder droplets.

    Science.gov (United States)

    Ma, Lin; Xu, Zhiwu; Zheng, Kun; Yan, Jiuchun; Yang, Shiqin

    2014-03-01

    The vibration characteristics of an aluminum surface subjected to ultrasonic waves were investigated with a combination of numerical simulation and experimental testing. The wetting behavior of solder droplets on the vibrating aluminum surface was also examined. The results show that the vibration pattern of the aluminum surface is inhomogeneous. The amplitude of the aluminum surface exceeds the excitation amplitude in some zones, while the amplitude decreases nearly to zero in other zones. The distribution of the zero-amplitude zones is much less dependent on the strength of the vibration than on the location of the vibration source. The surface of the liquid solder vibrates at an ultrasonic frequency that is higher than the vibration source, and the amplitude of the liquid solder is almost twice that of the aluminum surface. The vibration of the surface of the base metal (liquid solder) correlates with the oxide film removal effect. Significant removal of the oxide film can be achieved within 2s when the amplitude of the aluminum surface is higher than 5.4 μm or when the amplitude of the liquid solder surface is higher than 10.2 μm.

  3. Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates

    Directory of Open Access Journals (Sweden)

    Songling Huang

    2016-05-01

    Full Text Available This paper proposes a new cross-hole tomography imaging (CTI method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs. The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect’s thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.

  4. Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates.

    Science.gov (United States)

    Huang, Songling; Zhang, Yu; Wang, Shen; Zhao, Wei

    2016-05-02

    This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer) arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect's thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.

  5. Simulation research on ultrasonic guided waves detection of metal rod buffer system bonding quality

    Directory of Open Access Journals (Sweden)

    Yang Hu

    2013-01-01

    Full Text Available The judgment of metal rod buffer system bonding quality depends on the bond of the metal rods with the surrounding medium. System bonding area will lead to different reflection amplitude. Compared the simulation with the experiment, it can be concluded that different bonding area can measure bond quality, i.e, the greater the bonding area is the more excellent bonding quality will be. This conclusion provides the basis for the system ultrasonic testing.

  6. Ultrasonic Wave Appliacation in Decalcification of the Crude Oil of Liaohe%超声波在辽河原油脱钙中的应用

    Institute of Scientific and Technical Information of China (English)

    王英

    2009-01-01

    A high efficiency decalcification agent without phosphorus matter or metal content has been developed for Liaohe crude with high calcium content and calcium,nickel,iron and magnesium removel applied with the ultrasonic wave through the experimenin the crude before and after decalcification are analyzed by atomic absorption spectrometry, Influence of reacting time , ultrasonic wave frequency ,ultrasonic wave tense on remonal rate of metals were studied.The result showed that when filling water ratio was 10%,reacting time was 15 min, ultrasonic wave frequency was 28KHz ultrasonic wave tense was 8 Wcm-2 decalcification rate of Liaohe has reached more than 90% and the rate of the other three types metals has reached more than 70%.%针对辽河高钙原油研制开发了无磷不含金属的高效脱钙剂,利用原子吸收光谱法对原油在超声波作用下实验前后的钙、镍、铁及镁四种金属含量进行分析,考察了反应时间、超声波的频率及强度对原油脱金属率的影响.结果表明,注水串为10%、反应时间为15min,超声波的频率28kHz及强度8W·cm#时,原油的脱钙率达到90%以上,其它三种金属的脱除率达到70%以上.

  7. Liquid-Solid Interface Waves with Laser Ultrasonic and Mirage Effect

    Institute of Scientific and Technical Information of China (English)

    HAN Qing-Bang; WANG Hao; QIAN Meng-Lu

    2005-01-01

    @@ We experimentally investigate the transparent-liquid/solid (water/aluminum or steel) interface waves generated by laser pulses and detected by the Mirage effect. It is shown that nearly all kinds of liquid/solid interface waves in water are detected, both their measured wave velocities and characteristic of shape are in good agreement with theoretical predictions.

  8. High temperature ultrasonic transducers for the generation of guided waves for non-destructive evaluation of pipes

    Energy Technology Data Exchange (ETDEWEB)

    Sinding, K.; Searfass, C.; Malarich, N.; Reinhardt, B.; Tittmann, B. R. [Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA 16802 (United States)

    2014-02-18

    Applications for non-destructive evaluation and structural health monitoring of steam generators require ultrasonic transducers capable of withstanding the high temperatures of the pipes and heat exchangers. These applications require a strong coupling of the transducer to the heat exchanger’s complex geometry at the elevated temperatures. Our objective is to use spray-on piezo-electrics for depositing comb transducers onto the curved surfaces. This paper shows results for composite transducers such as lead zirconate titanate/ bismuth titanate and bismuth titanate/ lithium niobate. The comb transducers were prepared by precision laser ablation. The feasibility of producing second harmonic waves in rods with these spay-on comb transducers was demonstrated and paves the way toward measuring material degradation early-on before crack initiation occurs.

  9. High temperature ultrasonic transducers for the generation of guided waves for non-destructive evaluation of pipes

    Science.gov (United States)

    Sinding, K.; Searfass, C.; Malarich, N.; Reinhardt, B.; Tittmann, B. R.

    2014-02-01

    Applications for non-destructive evaluation and structural health monitoring of steam generators require ultrasonic transducers capable of withstanding the high temperatures of the pipes and heat exchangers. These applications require a strong coupling of the transducer to the heat exchanger's complex geometry at the elevated temperatures. Our objective is to use spray-on piezo-electrics for depositing comb transducers onto the curved surfaces. This paper shows results for composite transducers such as lead zirconate titanate/ bismuth titanate and bismuth titanate/ lithium niobate. The comb transducers were prepared by precision laser ablation. The feasibility of producing second harmonic waves in rods with these spay-on comb transducers was demonstrated and paves the way toward measuring material degradation early-on before crack initiation occurs.

  10. Research on novel inertial linear ultrasonic piezoelectric motor%新型惯性式直线超声压电电机的运动机理及实验研究

    Institute of Scientific and Technical Information of China (English)

    金家楣; 时运来; 李玉宝; 赵淳生

    2008-01-01

    A novel inertial linear ultrasonic piezoelectric motor is developed,which can transfer motion through friction in the form of inertial displacement by combining the converse piezoelectric effect and the principle of inertial displacement of piezoelectrical crystal.This motor is composed of a stator and a mobile element.The stator contains a displacement enlargement element,a multilayer piezoelectric actuator and a shaft and the mobile element is a ring with a gap and an annular flute.In this paper,the running principle of the motor is investigated in detail and the effects of two exciting modes on the performance of the motor is analyzed by the simulation and the experiment synchronously.ExPeri-mental results show that the excited effect of square wave signal on this motor is better than that of saw-tooth wave signal.The no-load speed of a prototype achieves 11 mm/s and the largest thrust achieves 0.5 N in operation voltage of 50 V and driving frequency of 80 kHz.%提出了一种新型惯性式直线超声压电电机.该电机利用压电晶体的逆压电效应和惯性位移原理,由定子的轴向变形,通过摩擦力的作用,以惯性位移的形式传递运动.它由两部分组成,定子由具有位移放大功能的压电复合换能器和轴组成,动子为一带有缺口和环形凹槽的环.分析了该电机的工作原理,并通过仿真和实验相结合的方法分析了两种激励方式对电机性能的影响.实验结果表明:样机采用方波驱动比采用锯齿波驱动的效果好;在采用方波驱动信号驱动时,样机的最大空载速度可达到11 mm/s,最大输出力达到0.5 N.

  11. Evaluation of fatigue cracks using nonlinearities of acousto-ultrasonic waves acquired by an active sensor network

    Science.gov (United States)

    Zhou, Chao; Hong, Ming; Su, Zhongqing; Wang, Qiang; Cheng, Li

    2013-01-01

    There has been increasing interest in using the nonlinear features of acousto-ultrasonic (AU) waves to detect damage onset (e.g., micro-fatigue cracks) due to their high sensitivity to damage with small dimensions. However, most existing approaches are able to infer the existence of fatigue damage qualitatively, but fail to further ascertain its location and severity. A damage characterization approach, in conjunction with the use of an active piezoelectric sensor network, was established, capable of evaluating fatigue cracks in a quantitative manner (including the co-presence of multiple fatigue cracks, and their individual locations and severities). Fundamental investigations, using both experiment and enhanced finite element analysis dedicated to the simulation of nonlinear AU waves, were carried out to link the accumulation of nonlinearities extracted from high-order AU waves to the characteristic parameters of a fatigue crack. A probability-based diagnostic imaging algorithm was developed, facilitating an intuitive presentation of identification results in images. The approach was verified experimentally by evaluating multi-fatigue cracks near rivet holes of a fatigued aluminum plate, showing satisfactory precision in characterizing real, barely visible fatigue cracks. Compared with existing methods, this approach innovatively (i) uses permanently integrated active sensor networks, conducive to automatic and online health monitoring; (ii) characterizes fatigue cracks at a quantitative level; (iii) allows detection of multiple fatigue cracks; and (iv) visualizes identification results in intuitive images.

  12. Low frequency ultrasonic multi-mode Lamb wave method for characterizing the ultra-thin transversely isotropic laminate composite: Theory and experiment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rui; WAN Mingxi; CHEN Xiao; CAO Wenwu

    2001-01-01

    A low-frequency multi-mode ultrasonic Lamb wave method suitable for characterizing the thickness, the density and the elastic constants of the ultra-thin transversely isotropic laminate composite is presented, The "ultra-thin" here means that the thickness of the plate is much less than the wavelength of the ultrasonic wave so that the echoes from the front and back faces of the plate can't be separated in the time domain. The dispersion equations for the low frequency ultrasonic Lamb waves with the propagation directions parallel and vertical to the fiber direction are derived. In conjunction with the least square algorithm method, the secant algorithm is used to estimate the parameters of the ultra-thin fiber-reinforced composite layer. The evaluation errors and the sensitivity of the method to different parameters of the thin composite are analyzed. The technique has been used to characterize the ultra-thin grass fiber reinforced PES composite with thickness down to ten percents of the ultrasonic wavelength. It is observed that the agreement between the nominal and the estimation values is reasonably good.

  13. Conditioning effect of transcranial magnetic stimulation evoking motor-evoked potential on V-wave response.

    Science.gov (United States)

    Grosprêtre, Sidney; Martin, Alain

    2014-12-01

    The aim of this study was to examine the collision responsible for the volitional V-wave evoked by supramaximal electrical stimulation of the motor nerve during voluntary contraction. V-wave was conditioned by transcranial magnetic stimulation (TMS) over the motor cortex at several inter-stimuli intervals (ISI) during weak voluntary plantar flexions (n = 10) and at rest for flexor carpi radialis muscle (FCR; n = 6). Conditioning stimulations were induced by TMS with intensity eliciting maximal motor-evoked potential (MEPmax). ISIs used were ranging from -20 to +20 msec depending on muscles tested. The results showed that, for triceps surae muscles, conditioning TMS increased the V-wave amplitude (~ +250%) and the associated mechanical response (~ +30%) during weak voluntary plantar flexion (10% of the maximal voluntary contraction -MVC) for ISIs ranging from +6 to +18 msec. Similar effect was observed at rest for the FCR with ISI ranging from +6 to +12 msec. When the level of force was increased from 10 to 50% MVC or the conditioning TMS intensity was reduced to elicit responses of 50% of MEPmax, a significant decrease in the conditioned V-wave amplitude was observed for the triceps surae muscles, linearly correlated to the changes in MEP amplitude. The slope of this correlation, as well as the electro-mechanical efficiency, was closed to the identity line, indicating that V-wave impact at muscle level seems to be similar to the impact of cortical stimulation. All these results suggest that change in V-wave amplitude is a great index to reflect changes in cortical neural drive addressed to spinal motoneurons.

  14. 超声波电动机在线校正模糊转速控制%Online Tuning Fuzzy Speed Control of Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    吕琳; 史敬灼

    2012-01-01

    Aiming at the speed control characteristics of ultrasonic motor, a fuzzy speed controller was designed for ultrasonic motor. Rules of the fuzzy controller were optimized offline using ant colony optimization, and the appropriate parameters of fuzzy controller were ascertained during the process of optimization. According to the difference between the responses with different speed values, a kind of online tuning method was proposed to modulate the proportional coefficient. Experiments indicate the validity of the proposed controller.%针对超声波电动机的转速控制特点,设计了超声波电动机模糊转速控制器.采用蚁群算法对模糊控制器中的模糊规则进行离线优化,确定合适的模糊控制器参数.在实验过程中,针对不同转速情况下的控制性能差异,给出了模糊控制器输出比例因子的在线调节方法,得到了较好的转速控制效果.

  15. Micro-driver for ultrasonic motors based on MSP430%基于MSP430的超声电机小型驱动器

    Institute of Scientific and Technical Information of China (English)

    俞浦; 李华峰; 李杰

    2011-01-01

    A scheme for a micro-driver for ultrasonic motor based on MSP430 was proposed. And then the hardware circuit structure was expounded in detail. The circuit was applied to an ultrasonic motor, of which the stator' s diameter is 60 mm. Experimental results showed that this scheme was valid and feasible. And it had several advantages, such as compact circuit, convenient regulation, steady running and so on.%提出了一种基于单片机MSP430的超声电机小型驱动器的设计方案,详述了该驱动器的硬件电路结构,并用它驱动TRUM60型超声电机,实验结果验证了该设计方案的合理性。该驱动器具有电路简洁,调节方便和运行稳定等优点。

  16. 超声波电动机特征模型的辨识建模%Identification of Ultrasonic Motor's Characteristic Model

    Institute of Scientific and Technical Information of China (English)

    尤冬梅; 史敬灼

    2012-01-01

    Characteristic model is one kind of identification model which can accurately describe the characteristics of object. Using experimental data,the modeling method of ultrasonic motor's characteristic model was proposed. The effect of different identification algorithms was compared. Aiming at the speed control of ultrasonic motor,the influence of parameter's initial values on the model was discussed. The calculating results indicate the availability of the characteristic model.%特征建模是一类能够准确逼近对象特性的辨识模型.基于实验数据,给出了超声波电动机特征模型的辨识建模方法,对比了不同辨识算法的建模效果.针对超声波电动机转速控制的特点,讨论了不同辨识参数初值对特征模型的影响.计算结果表明了所建特征模型的有效性.

  17. Measurement of shape by ultrasonic waves and surface inspection of the cold neutron source vertical hole

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kook Nam; Choi, Chang Oong; Sim, Cheul Mu; Choi, Young Hyun; Koo, Kil Mo [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-03-01

    Considerations in design of CNS containment, which will be put into the CNS installation hole, should be taken into obtaining the maximum gain by minimizing thickness of water film existing between walls of CN hole and the inserted containment and easy maintenance of the in-pile structures including the containment. In this experiment, inside diameter and thickness of the CN hole were measured and the possibility of the surface degradation was inspected in Hanaro which has been operated for about 4 years since its criticality in Feb, 1995. The result will be used in the design of containment. The data were obtained by measuring inside diameter and thickness for 550 points of CN hole using 2 channels of ultrasonic sensor. The result showed that the thickness is in the range of 3.3 {approx} 6.7 mm and inside diameter is in the range of {phi} 156 {approx} {phi} 165 mm. And this result was analyzed using plots and tables for making the visual shape understood better. Status of surface treatment and corrosion during 4 years of operation in highly radiated water was investigated through the surface inspection and the result was recorded on video-tape. This report will be used in design of the CNS containment, and the experiment for inserting the containment model will be followed next year. The 4-axis measuring manipulator developed in this measurement will be used for measuring shape of other experimental holes of Hanaro reactor, and also for detecting some indications in the radiation zone. This device will be applied in the other useful inspections in pool water during Hanaro ISI(In-service Inspection) after introducing automatic system for acquisition of ultrasonic signals. The 4-axis measuring manipulator will be applied for a patent with ultrasonic measuring system. (author). 19 refs., 99 figs., 5 tabs.

  18. Numerical studies of nonlinear ultrasonic guided waves in uniform waveguides with arbitrary cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Peng; Fan, Zheng, E-mail: ZFAN@ntu.edu.sg [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Zhou, Yu [Advanced Remanufacturing and Technology Center (ARTC), 3 Clean Tech Loop, CleanTech Two, Singapore 637143 (Singapore)

    2016-07-15

    Nonlinear guided waves have been investigated widely in simple geometries, such as plates, pipe and shells, where analytical solutions have been developed. This paper extends the application of nonlinear guided waves to waveguides with arbitrary cross sections. The criteria for the existence of nonlinear guided waves were summarized based on the finite deformation theory and nonlinear material properties. Numerical models were developed for the analysis of nonlinear guided waves in complex geometries, including nonlinear Semi-Analytical Finite Element (SAFE) method to identify internal resonant modes in complex waveguides, and Finite Element (FE) models to simulate the nonlinear wave propagation at resonant frequencies. Two examples, an aluminum plate and a steel rectangular bar, were studied using the proposed numerical model, demonstrating the existence of nonlinear guided waves in such structures and the energy transfer from primary to secondary modes.

  19. Ultrasonic actuators for nanometre positioning

    Science.gov (United States)

    Snitka

    2000-03-01

    This paper deals with ultrasonic motors based on bimodal plate vibrations and their application to nanometre resolution stepper positioning systems. The concept of a linear ultrasonic motor drive capable of nanometric steps, long-range travel and reversible controlled motion is presented. The motor concept developed is based on the superposition of a longitudinal and bending vibrations of a rectangular resonator. The ultrasonic motor model based on system identification via discrete observations and prediction has been developed for control applications. The control algorithm for ultrasonic motors has been developed and theoretical investigations have been made. The open loop positioning system with designed stepper ultrasonic drive produced 10 nm resolution and 5% displacement repeatability. The system with computer controlled position feedback has shown 0.3 micron positioning accuracy over the 100 mm positioning range.

  20. Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

    DEFF Research Database (Denmark)

    2010-01-01

    This invention relates to a plasma surface modification process (and a corresponding a system) of a solid object (100) comprising creating plasma (104) by a plasma source (106), application of the plasma (104) to at least a part of a surface (314) of the solid object (100), generating ultrasonic...... or a mixture of gases (500) flow in contact with said solid object (100) is thinned or destructed for at least a part of said surface (314). In this way, the plasma can more efficiently access and influence the surface of the solid object to be treated by the plasma, which speeds the process time up...

  1. 超声波电机推挽式驱动电源的设计制作%Development of the Push-pull Driving Circuit for Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    林星陵; 陈建毅

    2015-01-01

    The theory of ultrasonic motor and the mode of driving and control are different from traditional electromagnetic motor. In this paper, a simple driving circuit based on push-pull inverter for ultrasonic motor was fabricated according to the driving characteristic and requirement of the ultrasonic motor. The output of frequency, amplitude could be adjusted in a wide range. The experimental results indicate that the driving circuit with high reliability is suitable for ultrasonic motors driven by single-phase or two-phase signal.%超声波电机的工作原理及其驱动控制方式不同于传统的电磁电机。针对超声波电机的驱动特点和要求,本文运用推挽式逆变电路设计制作了一套简单实用的超声波驱动电源,该电源输出频率、输出电压都可在较宽的范围内调整。实际测试结果表明该电源性能稳定,能够满足两相或单相超声波电机的驱动要求,达到预期目标。

  2. Study of a new technique for measuring the travel time of ultrasonic waves using the frequency spectrum; Estudo de uma nova tecnica de medida do tempo de percurso da onda ultra-sonica usando o espectro de frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Allan Xavier dos

    2010-07-01

    During the operation of a nuclear plant and other industrial plants, the operational time and the exposition to severe working conditions may cause the wear of its components, consequently, compromising the safety and the performance of the installation. The implementation of periodical inspections helps to ensure the safe operation and the best performance of the plant. In this way, the use of ultrasonic techniques for inspection and materials characterization becomes more and more attractive, since they offer quick, precise results and are technically ease to implement. The usual ultrasonic techniques, need to the measure the travelling time of the ultrasonic wave in the material examined in order to extract information useful to characterize it. Thus, the measurement of the travelling time of the ultrasonic wave is the overriding factor in most of the applications made with ultrasound. In this work a new technique was developed for measuring the travelling time of the ultrasonic wave using a Fourier's Fast Transformer (FFT). It will be shown mathematically and experimentally that it is possible to use the ultrasonic signal in the frequency domain to determine the travelling time of the ultrasonic wave. Five experiments were carried out for the experimental validation of this new technique. The materials used were 20 ceramic pastilles with different porosities and 3 aluminum plates of different thicknesses. The obtained results have shown that the new technique proposed in this work was able to determine the travelling time of the ultrasonic wave with the same precision as the conventional technique. It was shown, furthermore, that this new technique is able to measure the travelling time of the ultrasonic wave in situations where the conventional technique cannot be applied greatly expanding the range of application of ultrasonic testing and inspections. (author)

  3. 中空柱状定子二阶弯振的旋转-直线超声电机%Rotary-linear ultrasonic motor based on second bending vibration mode of hollow cylindrical stator

    Institute of Scientific and Technical Information of China (English)

    程廷海; 郭向东; 包钢

    2013-01-01

    To improve the utilizing efficiency of PZT plates and simplify the fixing in the application of ultrasonic motor, a novel plate-attached rotary-linear ultrasonic motor was proposed. For the prototype, the second bending vibration modes of a hollow cylindrical stator were excited orthogonally both in time and space. And a traveling wave was synthesized in the free end of stator. The output shaft was driven by the traveling wave to move in a rotary-linear motion through the screw thread. The bending vibration mode of stator and excitation mode of PZT plates were simulated by finite element method. And then a prototype was developed, whose stator adopts a hollow square column structure. A testing system based on virtual instrument was established and the basic output characteristics of prototype were tested. Testing results indicate that the resonant frequency of the prototype is 38. 90 kHz, and can be driven availably under a peak-peak value of 20 V.%为了提高贴片式旋转-直线超声电机压电片的利用效率,简化电机使用过程中的安装与固定,提出了一种新颖的贴片式旋转-直线超声电机.样机主要利用自由约束柱状定子空间上相互正交的二阶弯曲振动模态耦合,在定子自由端的内表面合成一个驱动行波,通过螺纹传动实现输出轴的旋转-直线运动输出.基于有限元法对定子的振动模态以及压电片的激振模式进行了仿真分析,研制出一台定子采用中空方柱型结构的原型样机.搭建了一套基于虚拟仪器技术的超声电机测试系统,完成了样机基本输出特性的测试.测试结果表明样机工作频率为38.90 kHz,驱动电压峰峰值20 V时即可实现样机的有效驱动.

  4. Determination of resistance to salt crystallization on natural stone measured with ultrasonic wave

    DEFF Research Database (Denmark)

    Alm, D.; Brix, S.; Kjærgaard, H. Howe

    2008-01-01

    The use of panels as facade cladding has increased substantially during the last few decades. However, during recent years reports of facade problems have increased dramatically. Facade cladding has, in some cases, suffered from problems with durability such as exfoliation, disintegration of macr...... porosity while Perlatino has 1.1 % in open porosity. By means of ultrasonic measurements it is possible to detect damage in stones exposed to salt crystallization cycles. The results show a tendency to less resistance of salt crystallization for more porous materials....... of macrostructure and loss of strength. The damage may to some extent be accelerated by salt crystallization. This is an investigation of the durability of stones exposed to salt crystallization, by means of ultrasonic velocity measurements, compressive strength measurements and analysis of thin sections before...... and after salt exposure. Four different stones are investigated: the limestone Bateig Azul, the sandstone Oberkirchener, the limestone Perlatino, and the limestone Travertine. The procedure for the salt crystallization test is EN 12370 standard “Natural stone test methods – Determination of resistance...

  5. Preliminary study of slow and fast ultrasonic waves using MR images of trabecular bone phantom

    Energy Technology Data Exchange (ETDEWEB)

    Solis-Najera, S. E., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Neria-Pérez, J. A., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx; Medina, L., E-mail: solisnajera@ciencias.unam.mx, E-mail: angel.perez@ciencias.unam.mx, E-mail: lucia.medina@ciencias.unam.mx [Facultad de Ciencias, Universidad Nacional Autónoma de México, México, DF 04510 (Mexico); Garipov, R., E-mail: ruslan.garipov@mrsolutions.co.uk [MR Solutions Ltd, Surrey (United Kingdom); Rodríguez, A. O., E-mail: arog@xanum.uam.mx [Departamento Ingeniería Eléctrica, Universidad Autónoma Metropolitana Iztapalapa, México, DF 09340 (Mexico)

    2014-11-07

    Cancellous bone is a complex tissue that performs physiological and biomechanical functions in all vertebrates. It is made up of trabeculae that, from a simplified structural viewpoint, can be considered as plates and beams in a hyperstatic structure that change with time leading to osteoporosis. Several methods has been developed to study the trabecular bone microstructure among them is the Biot’s model which predicts the existence of two longitudinal waves in porous media; the slow and the fast waves, that can be related to porosity of the media. This paper is focused on the experimental detection of the two Biot’s waves of a trabecular bone phantom, consisting of a trabecular network of inorganic hydroxyapatite. Experimental measurements of both waves were performed using through transmission ultrasound. Results had shown clearly that the propagation of two waves propagation is transversal to the trabecular alignment. Otherwise the waves are overlapped and a single wave seems to be propagated. To validate these results, magnetic resonance images were acquired to assess the trabecular direction, and to assure that the pulses correspond to the slow and fast waves. This approach offers a methodology for non-invasive studies of trabecular bones.

  6. A study of the noncollinear ultrasonic-wave-mixing technique under imperfect resonance conditions

    NARCIS (Netherlands)

    Demcenko, A.; Mainini, L.; Korneev, V.A.

    2015-01-01

    Geometrical and material property changes cause deviations in the resonant conditions used for noncollinear wave mixing. These deviations are predicted and observed using the SV(ω1) + L(ω2) → L(ω1 + ω2) interaction, where SV and L are the shear vertical and longitudinal waves, respectively, and ω1,

  7. Numerical comparison of patch and sandwich piezoelectric transducers for transmitting ultrasonic waves

    CSIR Research Space (South Africa)

    Loveday, PW

    2006-03-01

    Full Text Available and this principle has been used to excite waves in a rail. This paper compares the two transduction approaches, for launching bending waves in rectangular waveguides, with numerical modeling. The numerical modeling combined a waveguide finite element model...

  8. Modal content based damage indicators and phased array transducers for structural health monitoring of aircraft structures using ultrasonic guided waves

    Science.gov (United States)

    Ren, Baiyang

    Composite materials, especially carbon fiber reinforced polymers (CFRP), have been widely used in the aircraft industry because of their high specific strength and stiffness, resistance to corrosion and good fatigue life. Due to their highly anisotropic material properties and laminated structures, joining methods like bolting and riveting are no longer appropriate for joining CFRP since they initiate defects during the assembly and severely compromise the integrity of the structure; thus new techniques for joining CFRP are highly demanded. Adhesive bonding is a promising method because it relieves stress concentration, reduces weight and provides smooth surfaces. Additionally, it is a low-cost alternative to the co-cured method which is currently used to manufacture components of aircraft fuselage. Adhesive defects, disbonds at the interface between adherend and adhesive layer, are focused on in this thesis because they can be initialized by either poor surface preparation during the manufacturing or fatigue loads during service. Aircraft need structural health monitoring (SHM) systems to increase safety and reduce loss, and adhesive bonds usually represent the hotspots of the assembled structure. There are many nondestructive evaluation (NDE) methods for bond inspection. However, these methods cannot be readily integrated into an SHM system because of the bulk size and weight of the equipment and requirement of accessibility to one side of the bonded joint. The first objective of this work is to develop instruments, actuators, sensors and a data acquisition system for SHM of bond lines using ultrasonic guided waves which are well known to be able to cover large volume of the structure and inaccessible regions. Different from widely used guided wave sensors like PZT disks, the new actuators, piezoelectric fiber composite (PFC) phased array transducers0 (PAT), can control the modal content of the excited waves and the new sensors, polyvinylidene fluoride (PVDF

  9. Ultrasonic flow meter

    NARCIS (Netherlands)

    Lötters, Joost Conrad; Snijders, G.J.; Volker, A.W.F.

    2014-01-01

    The invention relates to an ultrasonic flow meter comprising a flow tube for the fluid whose flow rate is to be determined. The flow meter comprises a transmitting element for emitting ultrasonic waves, which is provided on the outer jacket of the flow tube. A receiving element, which is provided on

  10. A model of TMS-induced I-waves in motor cortex.

    Science.gov (United States)

    Rusu, Cătălin V; Murakami, Max; Ziemann, Ulf; Triesch, Jochen

    2014-01-01

    Transcranial magnetic stimulation (TMS) allows to manipulate neural activity non-invasively, and much research is trying to exploit this ability in clinical and basic research settings. In a standard TMS paradigm, single-pulse stimulation over motor cortex produces repetitive responses in descending motor pathways called I-waves. However, the details of how TMS induces neural activity patterns in cortical circuits to produce these responses remain poorly understood. According to a traditional view, I-waves are due to repetitive synaptic inputs to pyramidal neurons in layer 5 (L5) of motor cortex, but the potential origin of such repetitive inputs is unclear. Here we aim to test the plausibility of an alternative mechanism behind D- and I-wave generation through computational modeling. This mechanism relies on the broad distribution of conduction delays of synaptic inputs arriving at different parts of L5 cells' dendritic trees and their spike generation mechanism. Our model consists of a detailed L5 pyramidal cell and a population of layer 2 and 3 (L2/3) neurons projecting onto it with synapses exhibiting short-term depression. I-waves are simulated as superpositions of spike trains from a large population of L5 cells. Our model successfully reproduces all basic characteristics of I-waves observed in epidural responses during in vivo recordings of conscious humans. In addition, it shows how the complex morphology of L5 neurons might play an important role in the generation of I-waves. In the model, later I-waves are formed due to inputs to distal synapses, while earlier ones are driven by synapses closer to the soma. Finally, the model offers an explanation for the inhibition and facilitation effects in paired-pulse stimulation protocols. In contrast to previous models, which required either neural oscillators or chains of inhibitory interneurons acting upon L5 cells, our model is fully feed-forward without lateral connections or loops. It parsimoniously explains

  11. Determination of resistance to salt crystallization on natural stone measured with ultrasonic wave

    DEFF Research Database (Denmark)

    Alm, D.; Brix, S.; Kjærgaard, H. Howe;

    2008-01-01

    The use of panels as facade cladding has increased substantially during the last few decades. However, during recent years reports of facade problems have increased dramatically. Facade cladding has, in some cases, suffered from problems with durability such as exfoliation, disintegration of macr...... porosity while Perlatino has 1.1 % in open porosity. By means of ultrasonic measurements it is possible to detect damage in stones exposed to salt crystallization cycles. The results show a tendency to less resistance of salt crystallization for more porous materials....... and after salt exposure. Four different stones are investigated: the limestone Bateig Azul, the sandstone Oberkirchener, the limestone Perlatino, and the limestone Travertine. The procedure for the salt crystallization test is EN 12370 standard “Natural stone test methods – Determination of resistance...

  12. Fluid-fluid interaction during miscible and immiscible displacement under ultrasonic waves

    Science.gov (United States)

    Hamida, T.; Babadagli, T.

    2007-12-01

    This paper aims at identifying and analyzing the influence of high-frequency, high-intensity ultrasonic radiation at the interface between immiscible (different types of oils and aqueous solutions) and miscible (different types of oil and solvent) fluids. An extensive set of Hele-Shaw type experiments were performed for several viscosity ratios, and interfacial tension. Fractal analysis techniques were applied to quantify the degree of fingering and branching. This provided a rough assessment of the degree of perturbation generated at the interface when the capillary forces along with the viscous forces are effective. Miscible Hele-Shaw experiments were also presented to isolate the effect of viscous forces. We found that ultrasound acts to stabilize the interfacial front, and that such effect is most pronounced at low viscosity ratios.

  13. Dispersion of Titanium Oxide Nanoparticles in Aqueous Solution with Anionic Stabilizer via Ultrasonic Wave

    Directory of Open Access Journals (Sweden)

    Wen-Bin Tsai

    2016-01-01

    Full Text Available This paper aims to reveal the effects of odium hexametaphosphate (SHMP and polyacrylic acid (PAA on dispersion of TiO2 (P25 nanopowder in de-ionic water through ultrasonic horn. We characterized TiO2 suspension by transmission electron microscopy (TEM, dynamic light scattering (DLS, Fourier transform infrared spectroscopy (FTIR, zeta potential, and surface contact angle instruments. As shown in the results, particularly, it were noticed that (1 the SHMP has better dispersion than PAA due to electronegativity effect, resulting in that the average particle size of the dispersed titanium dioxide in de-ionic water was roughly 92 nm, and (2 the zeta potential of TiO2 suspension with SHMP can be achieved by 54 mV at pH value of 7.7, causing stronger electrostatic repulsion in the suspension solution, compared with PAA.

  14. Surface ultrasonic envelope solitons and wave collapse in solid film-substrate systems

    Energy Technology Data Exchange (ETDEWEB)

    Grimalsky, V [National Institute for Astrophysics, Optics, and Electronics (INAOE), P.O. 51 and 216, ZP 72000, Puebla, Pue. (Mexico); Koshevaya [Research Center of Applied Sciences and Engineering (CIICAp), Autonomous University of State Morelos (UAEM), Av. Universidad No. 1001, ZP 62210, Cuernavaca, Mor. (Mexico); Gutierrez-D, E [National Institute for Astrophysics, Optics, and Electronics (INAOE), P.O. 51 and 216, ZP 72000, Puebla, Pue. (Mexico); Kolokoltsev, O V [National Autonomous University of Mexico (UNAM), Center of Applied Science and Technological Development (CCADET), P.O. 70-186, ZP 04510, Campus UNAM, Mexico, D.F. (Mexico)

    2005-01-01

    An excitation of ultra-high frequency (100 MHz - 1 GHz) nonlinear envelope solitary acoustic waves, propagating along the interface between a solid film and a solid substrate, is theoretically analyzed. Both the quadratic nonlinearity and the cubic one are important in the case of the envelope waves. When generation of higher harmonics is reduced due to essential waveguide dispersion and the cubic nonlinearity due to the induced zero harmonic is dominating, a possibility of the envelope solitary pulse propagation and the spatial-temporal wave collapse exists, as demonstrated. When the cubic material nonlinearity reduces the associated cubic nonlinear term, there also exists a possibility to observe a wave collapse, if the initial focusing of the input pulse at the first harmonic is applied.

  15. MR imaging of heterogeneity in partially frozen brine and their effect on ultrasonic wave propagation

    Science.gov (United States)

    Pradhan, O.; Matsushima, J.; Suzuki, M.

    2012-12-01

    Methane hydrate bearing sediment possesses unique seismic wave propagation properties. Both high seismic wave velocity and high wave attenuation are observed in methane hydrate bearing sediment. We used brine with salinity 2% in analogous to methane hydrate for conducting laboratory waveform measurement and characterization by using nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) technique. When brine undergoes freezing, only pure water freezes into ice and salt remains in solution with successively increasing salinity and decreasing freezing point of the solution. Unfrozen brine is enclosed inside micro pores in ice, with exhibiting solid-liquid coexisting system. We used conventional pulse transmission technique to measure compressional wave velocity in partially frozen brine when brine is subjected cooling down to -12oC. Waveform measurement shows sudden increase in compressional wave velocity at temperature -3oC. Below -3oC, velocity increases slightly. Largest wave attenuation is observed at around -3oC. We conducted MRI experiment by using instrument Varian Unity Inova 4.7T. T1 weighted and diffusion weighted (DW) MR images were prepared by applying magnetic field gradient of 0.3 gauss/cm. We observe the spatial distribution of pores, microstructures and heterogeneity in partially frozen brine sample slices. Two dimensional apparent diffusion coefficient (ADC) maps are prepared from DW images with b-values 0 and 81 s/mm2 respectively. We estimate porosity quantitatively from each MR slices at temperature -3, -5, -7 and -12oC by using image analysis technique. Gassmann equation is applied to calculate compressional wave velocity from the porosity data and compared with the measured velocity obtained by waveform analysis technique. The NMR results show the existence of high and low mobility unfrozen brine in the pore space. MR imaging shows the heterogeneously distributed porosity values within a single slice with low porosity and high

  16. Research on Driving and Controlling of Ultrasonic Motor Based on Characteristic of Impedance Angle%基于阻抗角特性的超声电机驱动控制研究

    Institute of Scientific and Technical Information of China (English)

    雷向红; 曾劲松; 李伟

    2011-01-01

    驱动控制对于超声电机的推广和应用十分重要.根据超声波电机的工作特点,该文分析温度变化对超声电机运行状态的影响,开发了一种基于驱动电压和电流相位差的驱动控制器,分析了各个控制部分的作用和设计方法,并进行了比较实验,结果表明这种控制系统能够达到稳定超声电机运行状态的目的.%Driving and control techniques are very important for applications of ultrasonic motor.According to the work characteristics of ultrasonic motor, the influence of the temperature variety upon the movement status of ultrasonic motor was analyzed.A new controller based on the phase difference between the driving voltage and electric current was designed.Analyzed the function and design method of each control part,and carried on the compare experiment.Result show that this kinds of control system can attain the purpose of stabling the status of ultrasonic motor.

  17. Excitation of ultrasonic Lamb waves using a phased array system with two array probes: phantom and in vitro bone studies.

    Science.gov (United States)

    Nguyen, Kim-Cuong T; Le, Lawrence H; Tran, Tho N H T; Sacchi, Mauricio D; Lou, Edmond H M

    2014-07-01

    Long bones are good waveguides to support the propagation of ultrasonic guided waves. The low-order guided waves have been consistently observed in quantitative ultrasound bone studies. Selective excitation of these low-order guided modes requires oblique incidence of the ultrasound beam using a transducer-wedge system. It is generally assumed that an angle of incidence, θi, generates a specific phase velocity of interest, co, via Snell's law, θi=sin(-1)(vw/co) where vw is the velocity of the coupling medium. In this study, we investigated the excitation of guided waves within a 6.3-mm thick brass plate and a 6.5-mm thick bovine bone plate using an ultrasound phased array system with two 0.75-mm-pitch array probes. Arranging five elements as a group, the first group of a 16-element probe was used as a transmitter and a 64-element probe was a receiver array. The beam was steered for six angles (0°, 20°, 30°, 40°, 50°, and 60°) with a 1.6-MHz source signal. An adjoint Radon transform algorithm mapped the time-offset matrix into the frequency-phase velocity dispersion panels. The imaged Lamb plate modes were identified by the theoretical dispersion curves. The results show that the 0° excitation generated many modes with no modal discrimination and the oblique beam excited a spectrum of phase velocities spread asymmetrically about co. The width of the excitation region decreased as the steering angle increased, rendering modal selectivity at large angles. The phenomena were well predicted by the excitation function of the source influence theory. The low-order modes were better imaged at steering angle ⩾30° for both plates. The study has also demonstrated the feasibility of using the two-probe phased array system for future in vivo study.

  18. 基于DDS超声波电机驱动电源系统的研究%Research of driving power of ultrasonic motor based on DDS

    Institute of Scientific and Technical Information of China (English)

    祁润田; 赵建光; 任卫东

    2012-01-01

    Using the converse piezoelectric effect generated by the mechanical vibration, ultrasonic motor can complete the electromechanical energy conversion with the advantages of insensitivity to magnetic fields, high torque at a low speed, low noise, fast response, high holding torque when power is off and so on. The ultrasonic motor is suitable for robots, precise positioning device, micro mechanical, aerospace and etc.. DDS is a widely used frequency synthesis technique with the advantages of easy programme control, fine frequency resolution and high digital integration. With ARM as the core of control circuit, the DDS technology was introduced to produce ultrasonic motor output waveform signal, which effectively solved some problems, such as the uncontrollability by programming for phase and frequency, the lower digital integration level, the larger size and the higher power consumption and so on.%超声波电机是利用压电陶瓷的逆压电效应产生的机械振动完成机电能量转换的,具有不受磁场影响、低速大力矩、低噪音、响应快和断电自锁能力强等优越性能,适合应用于机器人、精确定位装置、微型机械、航空航天器等方面.DDS是广泛应用的信号生成方法,其优点是易于程控,输出频率分辨率高,同时芯片的集成度高.以ARM作为控制电路核心,引入DDS技术产生超声波电机的输出波形信号,有效地解决了现有超声波电机压电陶瓷电源输出波形频率、相位等不能程控、电路集成度不高,体积和功耗较大等问题.

  19. Measurement Method of Load Characteristics for Bar Type Ultrasonic Motor in Vacuum Environment%真空环境下杆式超声波电动机负载特性的测量方法

    Institute of Scientific and Technical Information of China (English)

    王中营; 邓遵义; 陈宇; 焦群英

    2011-01-01

    To realize measurement on the load characteristics of the bar type ultrasonic motor in vacuum environment quickly, a transient response test system of the ultrasonic motor was developed based on the measurement principle of the transient response method. The system can be used to measure the transient response of the ultrasonic motor in starting 10 ms accurately and can also be used to calculate the load characteristics indirectly. The load characteristics of the bar type ultrasonic motor were measured using the hanging weight method and the system respectively. Experimental results show that the measurement results by using the two methods are agree well with each other and the transient response method for measuring the load characteristics of ultrasonic motor is feasible. Then in different vacuum environment, the measurement of the transient response and the load characteristics for the ultrasonic motor were achieved by using the transient response method. The results show that the method can be used to measure the load characteristics of the ultrasonic motor in vacuum environment.%为实现杆式超声波电动机在真空环境中负载特性的快速测量,根据瞬态响应法测量负载特性的基本原理,研制出超声波电动机瞬态响应测试系统,该系统能够实现超声波电动机在起动10 ms内转速瞬态响应的测量和负载特性的间接计算.在常态环境中采用挂砝码法和瞬态响应法对φ30mm杆式超声波电动机的负载特性进行了测量,两者测试结果基本一致,证明瞬态响应法用于测量超声波电动机的负载特性是可行的.随后在真空环境中,采用瞬态响应法实现了杆式超声波电动机瞬态响应和负载特性的测量,表明该方法适用于超声波电动机在真空环境中负载特性的测量.

  20. Speed control of ultrasonic motor based on H∞mixed-sensitivity design method%基于 H∞混合灵敏度方法的超声波电机调速控制

    Institute of Scientific and Technical Information of China (English)

    潘鹏; 徐志科; 金浩; 金龙; 陈爽; 黄帆; 冷静雯

    2015-01-01

    For travelling wave type ultrasonic motors,in order to improve speed tracking's accuracy and stability,and to enhance speed regulation performance owing to the nonlinearity of frequency modulation and speed regulation,the H∞ mixed-sensitivity design method is adopted to design the speed controller.Based on parameter identification,the model of motor's speed and frequency is estab-lished.It is linearized to get the motor's nominal model,with the gain variation transformed from non-linearity of the static model,the higher-order modeling error from the parametric variation of the dy-namic model,and the sum of the nominal model and the error model from the motor's speed model. According to model error bound and the speed regulation performance index,the mixable sensibility weighing function is solved,and the design of the speed controller is converted into standard H∞opti-mization problem.The robust controller is calculated by Matlab tools.The simulation results verify the control system's robustness.The robust controller is also realized in the digital signal processor TMS320F28335 and the motor's speed control performance is tested.The experimental results demon-strate that the speed control system applied to ultrasonic motor may provide a good control effect.%为提高行波型超声波电机转速跟踪的准确性和平稳性,改善因调频调速非线性带来的调速性能变化,将 H∞混合灵敏度方法应用于转速控制器的设计。采用参数辨识法建立电机的频率转速模型,线性化得到电机的标称模型,将静态模型的非线性转化为标称模型的增益摄动,将动态模型的参数变化转化为标称模型的高阶未建模误差,把电机的转速模型表示为标称模型与误差模型和。根据模型误差界和调速性能指标,求取混合灵敏度加权函数,将控制器设计转化为标准的 H∞优化问题,通过 Matlab 工具求解鲁棒控制器。仿真验证了转速闭环的

  1. The development of radiation hardened robot for nuclear facility; development of ultrasonic guided wave evaluation technology for the in-service/post-repair inspection of steam generator tubings

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Youn Ho [Inje University, Kimhae (Korea)

    2002-04-01

    The Potential of Ultrasonic Guided Waves which can propagate along the geometry of structures was explored for the inspection of such various components of nuclear power plants as tubings, pipings and plate-like structures etc. In this project, the fundamental research on the various aspects of guided wave modal characteristics was carried out to provide physically based guidelines which are essential to implement the guided waves as a promising inspection tool in the near future. The efforts for guided wave research include both theoretical and experimental works to make it possible to transfer the technology to power industry beyond the scope of pure academic subject. In the theoretical works, the softwares for the dispersion curves and wave structures of both layered structures and cylindrical ones were developed in the aims of mode identification and determination of probe design parameters. 40 refs., 92 figs., 14 tabs. (Author)

  2. Research on model testing of a new ultrasonic multi-wave detecting method

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The traditional crack exploring method with echo (reflected wave) in metals is called the "single-wave detecting method" that uses a probe of single weight. This method is not able to detect directly the size and shape of the crack and the result can only be obtained by relative comparison, that is to compare the echo amplitudes of the unknown quantity (crack) with the known quantity (regular artificial crack) to determine the equivalent size and shape of a certain crack. In this way, the site of a crack can be basically determined, but it is not the size, scale and site of the actual crack. So the traditional method is incapable to satisfy the demands in real applications, and there was not any big improvement in the past several decades. Therefore, we introduce a new method called the "multi-wave detecting method" in the paper, which is capable to detect directly the size, scale and site of a crack.

  3. Numerical simulation of ultrasonic waves in an isotropic elastic layer with a piezoelectric actuator

    Directory of Open Access Journals (Sweden)

    Andrey V. Pivkov

    2016-12-01

    Full Text Available This paper is dedicated to finite-element modeling (FEM of elastic waves caused by the work of a piezoactuator. For this purpose, a mathematical model of the ‘elastic layer—piezoelectric element’ system has been developed. In the terms of the model, the simultaneous solution of the piezoelectricity and the solid-mechanics equations was employed. This model allowed us to describe the propagation process of high-frequency mechanical vibrations caused by the application of the probing electrical pulse to the electrodes of the piezoelectric element (the vibrations occur in the elastic layer and to reproduce the potential difference arising in the reception of the reflected wave. The influence of t-parameters of the FEM and numerical integration scheme on the calculation results was investigated. The essential sensitivity of the reflected-wave's delay-time to the integrating time-step was found.

  4. A novel ultrasonic NDE for shrink fit welded structures using interface waves.

    Science.gov (United States)

    Lee, Jaesun; Park, Junpil; Cho, Younho

    2016-05-01

    Reactor vessel inspection is a critical part of safety maintenance in a nuclear power plant. The inspection of shrink fit welded structures in a reactor nozzle can be a challenging task due to the complicated geometry. Nozzle inspection using pseudo interface waves allows us to inspect the nozzle from outside of the nuclear reactor. In this study, layered concentric pipes were manufactured with perfect shrink fit conditions using stainless steel 316. The displacement distributions were calculated with boundary conditions for a shrink fit welded structure. A multi-transducer guided wave phased array system was employed to monitor the welding quality of the nozzle end at a distance from a fixed position. The complicated geometry of a shrink fit welded structure can be overcome by using the pseudo interface waves in identifying the location and size of defects. The experimental results demonstrate the feasibility of detecting weld delamination and defects.

  5. Equivalent Circuit Modeling of a Rotary Piezoelectric Motor

    DEFF Research Database (Denmark)

    El, Ghouti N.; Helbo, Jan

    2000-01-01

    In this paper, an enhanced equivalent circuit model of a rotary traveling wave piezoelectric ultrasonic motor "shinsei type USR60" is derived. The modeling is performed on the basis of an empirical approach combined with the electrical network method and some simplification assumptions about...

  6. An optodynamic determination of the depth of laser-drilled holes by the simultaneous detection of ultrasonic waves in the air and in the workpiece.

    Science.gov (United States)

    Strgar, Simon; Mozina, Janez

    2002-05-01

    A sufficiently powerful pulsed-laser beam can be used to 'drill' a hole in a stainless-steel workpiece. Here we present a real-time method for determining the depth of such a hole produced by multi-pulse laser drilling with a Q-switched Nd:YAG laser. The developed experimental setup allowed us to detect the laser-induced ultrasonic waves in the surrounding air and in the workpiece simultaneously by means of a probe-beam-deflection method and a piezoelectric transducer. Our optodynamic approach involved an analysis of these ultrasonic waves in order to determine the depth of the hole at any stage of the process. The increasing depth of the hole and its maximum extent were estimated from changes in the propagation time of the ultrasonic waves traveling from the bottom of the hole to both detectors. Measurements of the maximum hole depth were compared with the predictions of a theoretical model and they were found to be in a good agreement.

  7. 超声导波检测技术的发展、应用与挑战%Development,applications and challenges in ultrasonic guided waves testing technology

    Institute of Scientific and Technical Information of China (English)

    何存富; 吴斌; 郑明方; 吕炎; 邓鹏; 赵华民; 刘秀成; 宋国荣; 刘增华; 焦敬品

    2016-01-01

    回顾了近三十年的超声导波技术发展及应用,阐述了导波的频散现象及其求解方法,深入分析了导波激励的力学加载原理和模态选择原则。论述了导波的传感激励方法与装置,并比较了各种激励接收方法的特点与应用场合。对超声导波在板类、管类和复合材料中的应用进行了评述,并从提高缺陷检测能力的角度,介绍了时间反转法和相控阵法在超声导波技术中的应用。最后总结了当前导波技术面临的机遇与挑战。%This paper gives an overview of the development and application of guided waves technique for NDT&E in recent 30 years. Firstly,the fundamental concepts of guided waves propagation and their characteristics are explained,and the mechanical loading principles and mode selection principles for guided wave excitation is analyzed thoroughly.Secondly,the transducer excitation method and its apparatus for ultrasonic guided waves are introduced,then the features and applications are discussed among different excitation methods.Thirdly,ultrasonic guided wave applications in plates,tubes and composite materials are described,meanwhile,the time reversal and the phased array method are introduced to improve the capability of defect detection.Finally,the challenges and opportunities in of guided ultrasonic waves in future are outlined.

  8. 四梁耦合振子式超声波电动机的研制与实验%Research and Experiment on Four Beam Coupled Oscillator Model Type Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    张辉; 洪尚任; 鲍时超; 乔木

    2012-01-01

    The four beam coupled oscillator model type ultrasonic motor drive mechanism was studied. A new structure motor of the four beam coupled oscillator model type ultrasonic motor was designed and manufactured, and the experimental test was made. Results indicate that the type of motor was simple and compact structure, and had good performance , such as fast response speed, good control characteristics and low-speed and large torque. The expected design objective was obtained. The development of modal transformation type ultrasonic motor have practical significance and reference value.%对四梁耦合振子式超声波电动机的驱动机理进行了研究,设计并制作了四梁耦合振子式的新型结构电机,并进行了实验测试.实验结果表明,该类型电机不但结构简单紧凑,而且具有良好的输出性能,如反应速度快、控制特性好,低速大转矩等,设计达到了预期效果.该研究对模态转换型新型超声波电动机的研发有实际意义和参考价值.

  9. A base-sequence-modulated Golay code improves the excitation and measurement of ultrasonic guided waves in long bones.

    Science.gov (United States)

    Song, Xiaojun; Ta, Dean; Wang, Weiqi

    2012-11-01

    Researchers are interested in using ultrasonic guided waves (GWs) to assess long bones. However, GWs suffer high attenuation when they propagate in long bones, resulting in a low SNR. To overcome this limitation, this paper introduces a base-sequence-modulated Golay code (BSGC) to produce larger amplitude and improve the SNR in the ultrasound evaluation of long bones. A 16-bit Golay code was used for excitation in computer simulation. The decoded GWs and the traditional GWs, which were generated by a single pulse, agreed well after decoding the received signals, and the SNR was improved by 26.12 dB. In the experiments using bovine bones, the BSGC excitation produced the amplitudes which were at least 237 times greater than those produced by a single pulse excitation. The BSGC excitation also allowed the GWs to be received over a longer distance between two transducers. The results suggest the BSGC excitation has the potential to measure GWs and assess long bones.

  10. PMN-PT single crystal, high-frequency ultrasonic needle transducers for pulsed-wave Doppler application.

    Science.gov (United States)

    Zhou, Qifa; Xu, Xiaochen; Gottlieb, Emanuel J; Sun, Lei; Cannata, Jonathan M; Ameri, Hossein; Humayun, Mark S; Han, Pengdi; Shung, K Kirk

    2007-03-01

    High-frequency needle ultrasound transducers with an aperture size of 0.4 mm were fabricated using lead magnesium niobate-lead titanate (PMN-33% PT) as the active piezoelectric material. The active element was bonded to a conductive silver particle matching layer and a conductive epoxy backing through direct contact curing. An outer matching layer of parylene was formed by vapor deposition. The active element was housed within a polyimide tube and a 20-gauge needle housing. The magnitude and phase of the electrical impedance of the transducer were 47 omega and -38 degrees, respectively. The measured center frequency and -6 dB fractional bandwidth of the PMN-PT needle transducer were 44 MHz and 45%, respectively. The two-way insertion loss was approximately 15 dB. In vivo high-frequency, pulsed-wave Doppler patterns of blood flow in the posterior portion and in vitro ultrasonic backscatter microscope (UBM) images of the rabbit eye were obtained with the 44-MHz needle transducer.

  11. Influence of adhesive layer properties on laser-generated ultrasonic waves in thin bonded plates

    Institute of Scientific and Technical Information of China (English)

    Sun Hong-Xiang; Xu Bai-Qiang; Zhang Hua; Gao Qian; Zhang Shu-Yi

    2011-01-01

    This paper studies quantitatively the generation of Lamb waves in thin bonded plates subjected to laser illumination, after considering the viscoelasticity of the adhesive layer. The displacements of such plates have been calculated in the frequency domain by using the finite element method, and the time domain response has been reconstructed by applying an inverse fast Fourier transform. Numerical results are presented showing the normal surface displacement for several configurations: a single aluminum plate, a three-layer bonded plate, and a two-layer plate. The characteristics of the laser-generated Lamb waves for each particular case have been investigated. In addition, the sensitivity of the transient responses to variations of material properties (elastic modulus, viscoelastic modulus, and thickness) of the adhesive layer has been studied in detail.

  12. Laser photoacoustic technique for ultrasonic surface acoustic wave velocity evaluation on porcelain

    Science.gov (United States)

    Qian, K.; Tu, S. J.; Gao, L.; Xu, J.; Li, S. D.; Yu, W. C.; Liao, H. H.

    2016-10-01

    A laser photoacoustic technique has been developed to evaluate the surface acoustic wave (SAW) velocity of porcelain. A Q-switched Nd:YAG laser at 1064 nm was focused by a cylindrical lens to initiate broadband SAW impulses, which were detected by an optical fiber interferometer with high spatial resolution. Multiple near-field surface acoustic waves were observed on the sample surface at various locations along the axis perpendicular to the laser line source as the detector moved away from the source in the same increments. The frequency spectrum and dispersion curves were obtained by operating on the recorded waveforms with cross-correlation and FFT. The SAW phase velocities of the porcelain of the same source are similar while they are different from those of different sources. The marked differences of Rayleigh phase velocities in our experiment suggest that this technique has the potential for porcelain identification.

  13. Effects of adhesive, host plate, transducer and excitation parameters on time reversibility of ultrasonic Lamb waves.

    Science.gov (United States)

    Agrahari, J K; Kapuria, S

    2016-08-01

    To develop an effective baseline-free damage detection strategy using the time-reversal process (TRP) of Lamb waves in thin walled structures, it is essential to develop a good understanding of the parameters that affect the amplitude dispersion and consequently the time reversibility of the Lamb wave signal. In this paper, the effects of adhesive layer between the transducers and the host plate, the tone burst count of the excitation signal, the plate thickness, and the piezoelectric transducer thickness on the time reversibility of Lamb waves in metallic plates are studied using experiments and finite element simulations. The effect of adhesive layer on the forward propagation response and frequency tuning has been also studied. The results show that contrary to the general expectation, the quality of the reconstruction of the input signal after the TRP may increase with the increase in the adhesive layer thickness at certain frequency ranges. Similarly, an increase in the tone burst count resulting in a narrowband signal does not necessarily enhance the time reversibility at all frequencies, contrary to what has been reported earlier. For a given plate thickness, a thinner transducer yields a better reconstruction, but for a given transducer thickness, the similarity of the reconstructed signal may not be always higher for a thicker plate. It is important to study these effects to achieve the best quality of reconstruction in undamaged plates, for effective damage detection.

  14. 卧板式直线超声电机的特性分析模型%Modeling for Characteristic Analysis of a Plate-type Linear Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    张健滔; 李朝东; 何晓菁

    2012-01-01

    The frictional contact characteristics of the linear ultrasonic motor play a decisive role in motor performance.However,the friction drive mechanism of the linear ultrasonic motor is often different from that of the rotating ultrasonic motor.The contact model of the rotating ultrasonic motor cannot be used for its analysis.Therefore,a plate type linear ultrasonic motor was studied and its mathematical modeling for frictional contact analysis and characteristics estimation was developed based on the elastic contact theory.It was taken into consideration that the working status of the stator with or without the preload force is different and that the friction force is influenced by the relative sliding velocity between the stator and the slider.Simulated performance of the plate type linear ultrasonic motor was calculated using the developed model.The influences of the vibration characteristics of the stator,the preload force,the friction characteristics of the contact interface,the stiffness of the preload spring,and driving frequency on motor performance were discussed.The performance of a prototype motor was measured and compared with the simulation result.The experimental results show that the model for characteristics estimation of the linear ultrasonic motor is effective.The present model can be useful for the design and characteristic analysis of the same type of linear ultrasonic motors.%直线超声电机摩擦接触特性对电机性能的影响很大,直线超声电机的摩擦驱动机理往往不同于旋转超声电机,无法应用旋转超声电机的接触模型对其进行分析。针对一款卧板式直线超声电机,基于弹性接触理论建立了其摩擦接触分析及特性预估模型。该模型考虑了施加预压力后定子工作状态的改变,以及定、动子相对滑动速度差对摩擦力的影响。利用所建立的模型,对卧板式直线超声电机的机械输出特性进行了仿真计算,并分析了定子振动特性

  15. Impedance control in a wave-based teleoperator for rehabilitation motor therapies assisted by robots.

    Science.gov (United States)

    Mendoza, Marco; Bonilla, Isela; González-Galván, Emilio; Reyes, Fernando

    2016-01-01

    This paper presents an improved wave-based bilateral teleoperation scheme for rehabilitation therapies assisted by robot manipulators. The main feature of this bilateral teleoperator is that both robot manipulators, master and slave, are controlled by impedance. Thus, a pair of motion-based adaptive impedance controllers are integrated into a wave-based configuration, in order to guarantee a stable human-robot interaction and to compensate the position drift, characteristic of the available schemes of bilateral teleoperation. Moreover, the teleoperator stability, in the presence of time delays in the communication channel, is guaranteed because the wave-variable approach is included to encode the force and velocity signals. It should be noted that the proposed structure enables the implementation of several teleoperator schemes, from passive therapies, without the intervention of a human operator on the master side, to fully active therapies where both manipulators interact with humans in a stable manner. The suitable performance of the proposed teleoperator is verified through some results obtained from the simulation of the passive and active-constrained modes, by considering typical tasks in motor-therapy rehabilitation, where an improved behavior is observed when compared to implementations of the classical wave-based approach.

  16. Influence of intensity and frequency of ultrasonic waves on capillary interaction and oil recovery from different rock types.

    Science.gov (United States)

    Naderi, Khosrow; Babadagli, Tayfun

    2010-03-01

    Oil saturated cylindrical sandstone cores were placed into imbibition cells where they contacted with an aqueous phase and oil recovery performances were tested with and without ultrasonic radiation keeping all other conditions and parameters constant. Experiments were conducted for different initial water saturation, oil viscosity and wettability. The specifications of acoustic sources such as ultrasonic intensity (45-84W/sqcm) and frequency (22 and 40kHz) were also changed. An increase in recovery was observed with ultrasonic energy in all cases. This change was more remarkable for the oil-wet medium. The additional recovery with ultrasonic energy became lower as the oil viscosity increased. We also designed a setup to measure the ultrasonic energy penetration capacity in different media, namely air, water, and slurry (sand+water mixture). A one-meter long water or slurry filled medium was prepared and the ultrasonic intensity and frequency were monitored as a function of distance from the source. The imbibition cells were placed at certain distances from the sources and the oil recovery was recorded. Then, the imbibition recovery was related to the ultrasonic intensity, frequency, and distance from the ultrasonic source.

  17. Ultrasonic inspection of steam-generator tube axial cracking using Lamb wave

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Seok

    2007-02-15

    In this study, the interaction of Lamb wave propagating thin tube structure with finite vertical discontinuity was studied using both modal decomposition method (MDM) and experimental method. For MDM, a global matrix formulation and orthogonality of Lamb mode was employed to describe the boundary condition of finite vertical discontinuity of the tube and the mode conversion phenomenon respectively. The final form of governing equation by MDM was a linear matrix equation which could be solved using a simple matrix identity. The calculation result showed that, below the cut-off frequency, reflection amplitudes of both A0 and S0 Lamb mode increase as the depth of discontinuity increased beyond the threshold value. An experimental investigation was performed using a Hertzian-contact transducer and steam-generator tubes to verify the calculation results by MDM. A0 Lamb mode was selected as a test signal considering the characteristics of the transducer and previous studies. The experiment for mode identification using half-sectioned tube verified that the Hertzian-contact transducer effectively generated A0 Lamb mode. Tests performed using steam-generator tubes with EDM (electric discharge machined) axial notches showed that the deeper notches produced the higher reflection echo. A0 Lamb mode interacted with the notch having a depth larger than 1/40 of wave length, or corresponding to 30% of the wall thickness. This finding was in good agreement with previous studies and the prediction by MDM. The experiment using real crack specimens to estimate the deviation of reflection amplitude showed that the reflection cross-section of real crack was very similar with that of EDM notch. Therefore, specimens with EDM notches can be used as reference blocks for Lamb wave UT calibration.

  18. A coatable, light-weight, fast-response nanocomposite sensor for the in situ acquisition of dynamic elastic disturbance: from structural vibration to ultrasonic waves

    Science.gov (United States)

    Zeng, Zhihui; Liu, Menglong; Xu, Hao; Liu, Weijian; Liao, Yaozhong; Jin, Hao; Zhou, Limin; Zhang, Zhong; Su, Zhongqing

    2016-06-01

    Inspired by an innovative sensing philosophy, a light-weight nanocomposite sensor made of a hybrid of carbon black (CB)/polyvinylidene fluoride (PVDF) has been developed. The nanoscalar architecture and percolation characteristics of the hybrid were optimized in order to fulfil the in situ acquisition of dynamic elastic disturbance from low-frequency vibration to high-frequency ultrasonic waves. Dynamic particulate motion induced by elastic disturbance modulates the infrastructure of the CB conductive network in the sensor, with the introduction of the tunneling effect, leading to dynamic alteration in the piezoresistivity measured by the sensor. Electrical analysis, morphological characterization, and static/dynamic electromechanical response interrogation were implemented to advance our insight into the sensing mechanism of the sensor, and meanwhile facilitate understanding of the optimal percolation threshold. At the optimal threshold (˜6.5 wt%), the sensor exhibits high fidelity, a fast response, and high sensitivity to ultrafast elastic disturbance (in an ultrasonic regime up to 400 kHz), yet with an ultralow magnitude (on the order of micrometers). The performance of the sensor was evaluated against a conventional strain gauge and piezoelectric transducer, showing excellent coincidence, yet a much greater gauge factor and frequency-independent piezoresistive behavior. Coatable on a structure and deployable in a large quantity to form a dense sensor network, this nanocomposite sensor has blazed a trail for implementing in situ sensing for vibration- or ultrasonic-wave-based structural health monitoring, by striking a compromise between ‘sensing cost’ and ‘sensing effectiveness’.

  19. Study on the double transmission of ultrasonic waves through statistic rough surfaces

    Institute of Scientific and Technical Information of China (English)

    CHEN Ziqiang; CHEN Ligong; NI Chunzhen; WANG Yuwen

    2002-01-01

    A model evaluating the signal loss of the double transmitted acoustic beams through random rough surfaces was established based on the Fresnel approximation and phasescreen approximation. A simple analytical solution was achieved using the exponential substitution approach to remove the nonlinear integral terms. The factors that affect the signal of double transmissions from random rough surfaces were analyzed. The research results demonstrated that the signal loss is not only related to the root-mean-squire height of the roughness,but also to the distance of wave traveling in the materials. The model can be very helpful for improving the reliability of NDT (Non-Destructive Testing).

  20. Ultrasonic Approach of Rayleigh Pitch-Catch Contact Ultrasound Waves on CFRP Laminated Composites

    Institute of Scientific and Technical Information of China (English)

    In-Young Yang; Kwang-Hee Im; Uk Heo; David K Hsu; Je-Woong Park; Hak-Joon Kim; Sung-Jin Song

    2008-01-01

    CFRP (carbon fiber reinforced plastics) composite materials have wide applicability because of their inherent design flexibility and improved material properties. However, impacted composite structures have 50%-75% less strength than undamaged structures. In this work, a CFRP composite material was nondestructively characterized in order to ensure product quality and structural integrity of CFRP and one-sided pitch-catch technique was developed to measure impacted-damaged area by using an automated-data acquisition system in an immersion tank. A pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave under defect conditions in the composite.