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Sample records for brake pads

  1. Thermal Characterisation of Brake Pads

    DEFF Research Database (Denmark)

    Ramousse, Séverine; Høj, Jakob Weiland; Sørensen, O. T.

    2001-01-01

    The chemical-physical decomposition processes that occur in a brake pad heated to 1000degreesC have been studied. This temperature can be reached when a brake pad is applied. Thermogravimetry and differential thermal analysis were used in combination with evolved gas analysis, and image analysis...

  2. HEAT TRANSIENT TRANSFER ANALYSIS OF BRAKE DISC /PAD SYSTEM

    OpenAIRE

    Thuppal Vedanta, Srivatsan; Kora, Naga Vamsi Krishna

    2016-01-01

    Braking is mainly controlled by the engine. Friction between a pair of pads and a rotating disc converts the kinetic energy of the vehicle into heat. High temperatures can be reached in the system which can be detrimental for both, components and passenger safety. Numerical techniques help simulate load cases and compute the temperatures field in brake disc and brake pads. The present work implements a Finite Element (FE) toolbox in Matlab/Simulink able to simulate different braking manoeuvre...

  3. Development of Asbestos - Free Brake Pad Using Bagasse

    Directory of Open Access Journals (Sweden)

    V. S. Aigbodion

    2010-03-01

    Full Text Available Development of asbestos-free brake pad using bagasse was investigated with a view to replace the use of asbestos whose dust is carcinogenic. The bagasse were sieve into sieve grades of 100, 150, 250, 350 and 710µm. the sieve bagasse was used in production of brake pad in ratio of 70%bagasse-30%resin using compression moulding. The properties examined are microstructure analysis, hardness, compressive strength, density, flame resistance, water and oil absorption. The microstructure reveals uniform distribution of resin in the bagasse. The results obtained showed that the finer the sieve size the better the properties. The results obtained in this work were compared with that of commercial brake pad (asbestos based and optimum formulation laboratory brake pad Palm Kernel Shell based (PKS, the results are in close agreement. Hence bagasse can be used in production of asbestos-free brake pad.

  4. Impact of Brake Pad Structure on Temperature and Stress Fields of Brake Disc

    Directory of Open Access Journals (Sweden)

    Guoshun Wang

    2013-01-01

    Full Text Available Utilizing ABAQUS finite element software, the study established the relationship between a brake pad structure and distributions of temperature and thermal stress on brake disc. By introducing radial structure factor and circular structure factor concepts, the research characterized the effect of friction block radial and circumferential arrangement on temperature field of the brake disc. A method was proposed for improving heat flow distribution of the brake disc through optimizing the position of the friction block of the brake pad. Structure optimization was conducted on brake pads composed of 5 or 7 circular friction blocks. The result shows that, with the same overall contact area of friction pair, an appropriate brake pad structure can make the friction energy distribute evenly and therefore lowers peak temperature and stress of the brake disc. Compared with a brake pad of 7 friction blocks, an optimized brake pad of 5 friction blocks lowered the peak temperature of the corresponding brake disc by 4.9% and reduced the highest stress by 10.7%.

  5. Evaluation of Wear in Aftermarket Brake Pads for Enhancing Braking Performance in a Passenger Vehicle

    Directory of Open Access Journals (Sweden)

    Mohd Zaki Bahrom

    2016-08-01

    Full Text Available Nowadays, due to the high demands from the independence automotive service centers; there are many aftermarket brake pads available at spare parts shops and sold at reasonable prices. Several types of brake pads are available in the market such as semi-metallic and Non-Asbestos brake pads. The purpose of this study is to evaluate the wear of after-market brake pad performance under the normal driving conditions (highway and non-highway. Three types of aftermarket brake pads that mainly used and sold by independent service shop were selected in this study.  The data of the wear in thicknesses losses and weight percentage losses were recorded. The results show that brake pad of non- Asbestos Organic type gives the highest wear loss and create a lot of dust. For semi-metallic brake pad type, the result shows the lowest mass loss. Therefore, it is important to select the suitable type of after-market brake pads in order to get balance between cost and quality.

  6. Structure Topology Optimization of Brake Pad in Large- megawatt Wind Turbine Brake Considering Thermal- structural Coupling

    Science.gov (United States)

    Zhang, S. F.; Yin, J.; Liu, Y.; Sha, Z. H.; Ma, F. J.

    2016-11-01

    There always exists severe non-uniform wear of brake pad in large-megawatt wind turbine brake during the braking process, which has the brake pad worn out in advance and even threats the safety production of wind turbine. The root cause of this phenomenon is the non-uniform deformation caused by thermal-structural coupling effect between brake pad and disc while braking under the conditions of both high speed and heavy load. For this problem, mathematical model of thermal-structural coupling analysis is built. Based on the topology optimization method of Solid Isotropic Microstructures with Penalization, SIMP, structure topology optimization of brake pad is developed considering the deformation caused by thermal-structural coupling effect. The objective function is the minimum flexibility, and the structure topology optimization model of brake pad is established after indirect thermal- structural coupling analysis. Compared with the optimization result considering non-thermal- structural coupling, the conspicuous influence of thermal effect on brake pad wear and deformation is proven as well as the rationality of taking thermal-structural coupling effect as optimization condition. Reconstructed model is built according to the result, meanwhile analysis for verification is carried out with the same working condition. This study provides theoretical foundation for the design of high-speed and heavy-load brake pad. The new structure may provide design reference for improving the stress condition between brake pad and disc, enhancing the use ratio of friction material and increasing the working performance of large-megawatt wind turbine brake.

  7. THE INFLUENCE OF BRAKE PADS THERMAL CONDUCTIVITY ON PASSANGER CAR BRAKE SYSTEM EFFICIENCY

    Directory of Open Access Journals (Sweden)

    Predrag D Milenković

    2010-01-01

    Full Text Available In phase of vehicle braking system designing, besides of mechanical characteristics, it is also necessary to take under consideration the system's thermal features. This is because it is not enough just to achieve proper braking power, for the brake system to be effective but equally important thing is the dissipation of heat to the environment. Heat developed in the friction surfaces dissipate into the environment over the disk in one hand and through the brake linings and caliper, in the other. The striving is to make that greatest amount of heat to dissipate not threw the brake pads but threw disc. The experimental researching of heat transfer process taking place at vehicle brakes was made in the R&D Center of "Zastava automobili" car factory in order to increase the efficiency of brake system. The standard laboratory and road test procedures were used, according to factory quality regulations. The modern equipment such as thermo camera, thermo couples, torque transducers, signal amplifiers, optical speed measuring system and laptop computer were used. In this paper will be shown the part of the experimental researching, which refers to the thermal conductivity of brake pad friction linings.

  8. Investigation of the coatings applied onto brake discs on disc-brake pad pair

    Directory of Open Access Journals (Sweden)

    I. Kiliçaslan

    2009-07-01

    Full Text Available While braking, according to the severity of it, thermal, metallurgical, constructive and tribological occurrences emerge on the brake disc-pad interface. In this study, NiCr was sprayed as bonding layer onto the discs, one ofwhich was coated with Al2O3-TiO2 by plasma spray and the other was coated with NiCr-Cr3C2 by High Velocity Oxygen Fuel (HVOF. In addition, the discs were tested with inertia dynamometer according to SAE’s J2522 testing procedure. The measurements showed that although the pads of the coated discs were exposed to higher braking temperatures, friction coefficient of the disc coated with NiCr- Cr3C2 was obtained 6 % higher compared to the original disc.

  9. The effects of porosity in friction performance of brake pad using waste tire dust

    Directory of Open Access Journals (Sweden)

    İbrahim Mutlu

    2015-10-01

    Full Text Available Abstract This research is focused on the effect of porosity on the friction-wear properties of automotive brake pads. Waste Tire Dust (WTD was used as a new friction material in brake pads. Newly formulated brake pad materials with five different components have been produced by conventional techniques. In the experimental studies, the change of the friction coefficient, the temperature of the friction surface, the specific wear rate, and the hardness, density and porosity were measured. In addition, the micro-structural characterizations of brake pads are determined using Scanning Electron Microscopy (SEM. The mean coefficient of friction, porosity and specific wear are increased due to a WTD rate increases, on the other hand, hardness and density are decreased. As a result, WTD can be considered as an alternative to revalorize this kind of waste products in the brake pads and the amount of porosity of the brake pad affected the friction coefficient and wear behavior of the pad.

  10. Frictional and heat resistance characteristics of coconut husk particle filled automotive brake pad

    Science.gov (United States)

    Bahari, Shahril Anuar; Chik, Mohd Syahrizul; Kassim, Masitah Abu; Som Said, Che Mohamad; Misnon, Mohd Iqbal; Mohamed, Zulkifli; Othman, Eliasidi Abu

    2012-06-01

    The objective of this study was to determine the friction and heat resistance characteristics of automotive brake pad composed with different sizes and percentages of coconut husk particle. The materials used were phenolic resin (phenol formaldehyde) as binder, copper, graphite and brass as friction producer/modifiers, magnesium oxide as abrasive material, steel and barium sulfate as reinforcement while coconut husk particle as filler. To obtain particle, the coconut husk was ground and dried to 3% moisture content. Then the coconut husk particle was screened using 80 mesh (to obtain coarse dust) and 100 mesh (to obtain fine dust). Different percentages of particle, such as 10 and 30% were used in the mixture of brake pad materials. Then the mixture was hot-pressed to produce brake pad. Chase machine was used to determine the friction coefficient in friction resistance testing, while thermogravimetric analyzer (TGA) machine was used to determine the heat decomposition values in heat resistance testing. Results showed that brake pad with 100 mesh and 10% composition of coconut husk particle showed the highest friction coefficient. For heat resistance, brake pad with 100 mesh and 30% composition of coconut husk dust showed the highest decomposition temperature, due to the high percentage of coconut husk particle in the composition, thus increased the thermal stability. As a comparison, brake pad composed with coconut husk particle showed better heat resistance results than commercial brake pad.

  11. Morphology and properties of periwinkle shell asbestos-free brake pad

    Directory of Open Access Journals (Sweden)

    D.S. Yawas

    2016-01-01

    Full Text Available The development of asbestos-free automotive brake pad using periwinkle shell particles as frictional filler material is presented. This was with a view to exploiting the characteristics of the periwinkle shell, which is largely deposited as a waste, in replacing asbestos which has been found to be carcinogenic. Five sets of brake pads with different sieve size (710–125 μm of periwinkle shell particles with 35% resin were produced using compressive moulding. The physical, mechanical and tribological properties of the periwinkle shell particle-based brake pads were evaluated and compared with the values for the asbestos-based brake pads. The results obtained showed that compressive strength, hardness and density of the developed brake pad samples increased with decreasing the particle size of periwinkle shell from 710 to 125 μm, while the oil soak, water soak and wear rate decreased with decreasing the particle size of periwinkle shell. The results obtained at 125 μm of periwinkle shell particles compared favourably with that of commercial brake pad. The results of this research indicate that periwinkle shell particles can be effectively used as a replacement for asbestos in brake pad manufacture.

  12. Application Research on Self-healing Technology with Microcapsules for Automobile Brake Pad

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; DONG Xiuping; ZHANG Heng

    2009-01-01

    In order to improve the performance of non-asbestos composite auto brake pads that are composed of matrix resin, reinforced material and fillers, a novel method with new technology of self-heal microcapsules was proposed. Nano reinforced fillers' effects were also considered in the experiment project. Five recipe designs for new composite auto brake pads were carried out and cor-responding samples were prepared as well. The friction coefficient and wearing properties at certain temperature, impact intensity and hardness were comparatively studied. Investigations indicate that properties of such composite auto brake pads meet the requirements of the national standards while microcapsule's weight content varies from 5.5wt%-1.09wt% of matrix resin and microcapsule's loca-tion varies in the pads. Nano reinforced fillers have the effects of increasing composites' impact in-tensity and hardness. Application of self-healing microcapsules in auto brake pads is feasible.

  13. Numerical Analysis of Temperature Field in a Disc Brake at Different Cover Angle of the Pad

    Directory of Open Access Journals (Sweden)

    Grześ Piotr

    2014-12-01

    Full Text Available In the paper an influence of the cover angle of the pad on temperature fields of the components of the disc brake is studied. A three-dimensional finite element (FE model of the pad-disc system was developed at the condition of equal temperatures on the contacting surfaces. Calculations were carried out for a single braking process at constant deceleration assuming that the contact pressure corresponds with the cover angle of the pad so that the moment of friction is equal in each case analysed. Evolutions and distributions of temperature both for the contact surface of the pad and the disc were computed and shown.

  14. Morphology and properties of periwinkle shell asbestos-free brake pad

    OpenAIRE

    D.S. Yawas; S.Y.Aku; S.G. Amaren

    2016-01-01

    The development of asbestos-free automotive brake pad using periwinkle shell particles as frictional filler material is presented. This was with a view to exploiting the characteristics of the periwinkle shell, which is largely deposited as a waste, in replacing asbestos which has been found to be carcinogenic. Five sets of brake pads with different sieve size (710–125 μm) of periwinkle shell particles with 35% resin were produced using compressive moulding. The physical, mechanical and tribo...

  15. Reduced order brake models to study the effect on squal of pad redesign

    OpenAIRE

    Vermot Des Roches, Guillaume; Balmes, Etienne; CHIELLO, Olivier; Lorang, Xavier

    2013-01-01

    Brake squeal impacts trains during station parking, generating over 110 dB at the wheel vicinity. This disturbance is a problem for commuters and employees working close to trains and limits exploitation times. The only adjustable parameter is here the brake pad, since it is the only part with frequent replacement regarding the railway equipment lifetimes. To improve current pad design to limit noise emissions a numerical prototyping tool is required, providing noise level indicators post-tre...

  16. Low-impact friction materials for brake pads

    OpenAIRE

    2016-01-01

    State-of-the-art friction materials for applications in disc brake systems are constituted by composite materials, specifically formulated to ensure proper friction and wear performances, under the sliding contact conditions of braking events. The bases of typical friction compound formulations usually include 10 to 30 different components bonded with a polymeric binder cross-linked in situ. Main requests to be fulfilled during braking are an adequate friction efficiency and enough mechanical...

  17. A Computational Study on the Use of an Aluminium Metal Matrix Composite and Aramid as Alternative Brake Disc and Brake Pad Material

    Directory of Open Access Journals (Sweden)

    Nosa Idusuyi

    2014-01-01

    Full Text Available A computational model for the heat generation and dissipation in a disk brake during braking and the following release period has been formulated. The model simulates the braking action by investigating the thermal behaviour occurring on the disc and pad surfaces during this period. A comparative study was made between grey cast iron (GCI, asbestos, Aluminium metal matrix composite (AMC, and aramid as brake pad and disc materials. The braking process and following release period were simulated for four material combinations, GCI disc and Asbestos pad, GCI disc and Aramid pad, AMC disc and Asbestos pad, AMC disc and Aramid pad using COMSOL Multiphysics software. The results show similarity in thermal behaviour at the contact surface for the asbestos and aramid brake pad materials with a temperature difference of 1.8 K after 10 seconds. For the brake disc materials, the thermal behaviour was close, with the highest temperature difference being 9.6 K. The GCI had a peak temperature of 489 K at 1.2 seconds and AMC was 465.5 K but cooling to 406.4 K at 10 seconds, while the GCI was 394.7 K.

  18. Pad-mode-induced instantaneous mode instability for simple models of brake systems

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-10-01

    Automotive disc brake squeal is fugitive, transient and remains difficult to predict. In particular, instantaneous mode squeal observed experimentally does not seem to be associated with mode coupling and its mechanism is not clear. The effects of contact pressures, friction coefficients as well as material properties (pressure and temperature dependency and anisotropy) for brake squeal propensity have not been systematically explored. By analysing a finite element model of an isotropic pad sliding on a plate similar to that of a previously reported experimental study, pad modes have been identified and found to be stable using conventional complex eigenvalue analysis. However, by subjecting the model to contact pressure harmonic excitation for a range of pressures and friction coefficients, a forced response analysis reveals that the dissipated energy for pad modes is negative and becomes more negative with increasing contact pressures and friction coefficients, indicating the potential for instabilities. The frequency of the pad mode in the sliding direction is within the range of squeal frequencies observed experimentally. Nonlinear time series analysis of the vibration velocity also confirms the evolution of instabilities induced by pad modes as the friction coefficient increases. By extending this analysis to a more realistic but simple brake model in the form of a pad-on-disc system, in-plane pad-modes, which a complex eigenvalue analysis predicts to be stable, have also been identified by negative dissipated energy for both isotropic and anisotropic pad material properties. The influence of contact pressures on potential instabilities has been found to be more dominant than changes in material properties owing to changes in pressure or temperature. Results here suggest that instantaneous mode squeal is likely caused by in-plane pad-mode instabilities.

  19. Effect of periwinkles shell particle size on the wear behavior of asbestos free brake pad

    Science.gov (United States)

    Amaren, S. G.; Yawas, D. S.; Aku, S. Y.

    The effect of periwinkle shell particle size on the wear behavior of asbestos free brake pad has been investigated. The asbestos free brake pad produced by varying the periwinkle shell particles was from +125 to +710 μm with phenolic resin as the binder. The wear test was performed using pin on disk machine by varying the sliding speed, applied load, temperatures and periwinkle shell particle size. Full factorial design of four factor-two levels and analysis of variance were used in the study of the wear test. The results shown that wear rate increases with increasing the sliding speed, load, temperatures and periwinkle particle size. The co-efficient of friction obtained is within the recommended standard for automobile brake pad. The +125 μm particles of periwinkles gave the best wear resistance. Factorial design of the experiment can be successfully employed to describe the wear behavior of the samples and developed linear equation for predicting wear rate within selected experimental conditions. The results of this research indicate that periwinkle shell particles can be effectively used as a replacement for asbestos in brake pad manufacture.

  20. Optimization of Tribological Properties of Nonasbestos Brake Pad Material by Using Steel Wool

    Directory of Open Access Journals (Sweden)

    R. Vijay

    2013-01-01

    Full Text Available The gradual phasing out of typical brake pad material led to the spark of extensive research in development of alternatives. Henceforth we have performed a tribological study to improve the performance characteristics of the friction product (brake pad by using steel wool, a metallic material which has an excellent structural reinforcement property and high thermal stability which are indeed required to improve the performance of the brake pad. Under the study, five frictional composites were developed and optimized using the same ingredients in an appropriate proportion except steel wool (0%, 4%, 8%, 12%, and 16% which is compensated by synthetic barite, and the synthesized compositions are designated as Na01 to Na05. The developed pads are tested for tribological behaviour under conventional environment in a standard pin on disc tribometer. It is observed that increase in steel wool concentration resulted in high coefficient of friction and low wear rate of pad as resulted in Na05 composition. SEM analysis of the wear surface has proved to be useful in understanding the wear behaviour of the composites.

  1. Evaluation of palm kernel fibers (PKFs for production of asbestos-free automotive brake pads

    Directory of Open Access Journals (Sweden)

    K.K. Ikpambese

    2016-01-01

    Full Text Available In this study, asbestos-free automotive brake pads produced from palm kernel fibers with epoxy-resin binder was evaluated. Resins varied in formulations and properties such as friction coefficient, wear rate, hardness test, porosity, noise level, temperature, specific gravity, stopping time, moisture effects, surface roughness, oil and water absorptions rates, and microstructure examination were investigated. Other basic engineering properties of mechanical overload, thermal deformation fading behaviour shear strength, cracking resistance, over-heat recovery, and effect on rotor disc, caliper pressure, pad grip effect and pad dusting effect were also investigated. The results obtained indicated that the wear rate, coefficient of friction, noise level, temperature, and stopping time of the produced brake pads increased as the speed increases. The results also show that porosity, hardness, moisture content, specific gravity, surface roughness, and oil and water absorption rates remained constant with increase in speed. The result of microstructure examination revealed that worm surfaces were characterized by abrasion wear where the asperities were ploughed thereby exposing the white region of palm kernel fibers, thus increasing the smoothness of the friction materials. Sample S6 with composition of 40% epoxy-resin, 10% palm wastes, 6% Al2O3, 29% graphite, and 15% calcium carbonate gave better properties. The result indicated that palm kernel fibers can be effectively used as a replacement for asbestos in brake pad production.

  2. Generation of Nanoparticles from Friction between Railway Brake Disks and Pads.

    Science.gov (United States)

    Namgung, Hyeong-Gyu; Kim, Jong-Bum; Woo, Sang-Hee; Park, Sechan; Kim, Minhae; Kim, Min-Soo; Bae, Gwi-Nam; Park, Duckshin; Kwon, Soon-Bark

    2016-04-01

    In this study, we measured the size distribution of particles ranging in size from 5.6 to 560 nm that were emitted between brake disks and pads under various braking conditions to observe and analyze changes to the resulting particle size distribution over braking time. A peak of 178-275 nm (200 nm peak) was observed in all braking conditions. However, the generation of spherical particles of a 10 nm range was observed only when the disk speed and brake force were above certain levels and intensified only when speed and brake force further increased. The total number concentration of ultrafine particles (no larger than 0.1 μm; PM0.1) generated was found to correlate with disk speed and brake force. Thus, the generation of nanoparticles resulting from disk speed and brake force was attributable primarily to increases in the contact surface temperature. The critical temperature for the generation of nanoparticles of a 10 nm range was found to be about 70 °C, which is the average temperature between the surface and the inside of the disk. If the speed or brake force was higher, that is, the temperature of the contact surface reached a certain level, evaporation and condensation took place. Vapor then left the friction surface, met with the air, and quickly cooled to form nanoparticles through nucleation. When the newly generated particles became highly concentrated, they grew through coagulation to form agglomerates or the vapor condensed directly onto the surface of existing particles of about 200 nm (formed by mechanical friction).

  3. Tribological properties of nonasbestos brake pad material by using coconut fiber

    Science.gov (United States)

    Craciun, A. L.; Pinca-Bretotean, C.; Utu, D.; Josan, A.

    2017-01-01

    In automotive industry, the brake system is influenced by a large number of variables including geometry of components, materials of brakes, components interaction and many operating condition. Organic fiber reinforced metallic friction composites are increasingly being used in automotive brake shoes, disc and pads, linings, blocks, clutch facings, primarily because of awareness of health hazards of asbestos. Current trend in the research field of automotive industry is to utilization of different wastes as a source of raw materials for composite materials. This will provide more economical benefit and also environmental preservation by utilize the waste of natural fibre In this paper it has performed a tribological study to determine the characteristics of the friction product by using coconut natural fibred reinforced in aluminium composite. In this sense, two different laboratory formulation were prepared with 5% and 10% coconut fibre and other constitutes like binder, friction modifiers, abrasive material and solid lubrificant using powder mettallurgy. These dnew materials for brake pads are tested for tribological behaviour in a standard pin on disc tribometer. To know the wear behavior of composite materials will determine the parameters that characterize there tribological properties.

  4. Development of Refined Natural Resin based Cashew Nut Shell Oil Liquid (CNSL) for Brake Pads Composite

    Science.gov (United States)

    Wahyuningsih, S.; Ramelan, A. H.; Rahmawati, P.; Tamtama, B. P. N.; Sari, P. P.; Sari, P. L.; Ichsan, S.; Kristiawan, Y. R.; Aini, F. N.

    2017-02-01

    Brake is one of the most important components in the vehicle. One type of brake that widely used is brake-based composites. One of the manufacture of composite material is resin. Cashew Nut Shell Liquid (CNSL) is a natural material which has chemical structure similar to synthetic phenol so it can be an alternative as a resin. Brake pads manufacture using CNSL as resin composites made to obtain the brake which is strong, wear-resistant, and environmentally friendly. The composite made using powder metallurgy techniques by mixing ingredients such as rubber, fibre glass, carbon, mineral sands and phenolic resin. Two formulas were composed by varying the resin and iron mineral sands in 5 grams. Composites were tested using Universal Testing Machine (UTM). The tensile strength result of those formulas are 600 N and 900 N and the elongations are 1.98 mm and 2.59 mm respectively. Formula 2 has a better tensile strength due to the addition of more resin is 15%. Since the better properties, formula 2 was derivated to 4 extended formulas and showed excellent pressure strength reached 20.000 N. It indicates that the addition of the resin can improve the mechanical properties of a composite.

  5. Friction and wear studies on the temperature dependence of brake-pad materials containing brass

    Directory of Open Access Journals (Sweden)

    Eddoumy Fatima

    2013-11-01

    Full Text Available Brake pad materials for automobile applications are basically polymer matrix composites. Various reinforcing constituents used in brake pads are organic, metallic and ceramic fillers which play among others an important role on the mechanical and thermal properties, and the wear resistance at high temperature. Friction and wear depend on various parameters such as the micro-chemical structure of the pad and of the metallic counter-face, the rotation speed, the pressure, and the contact surface temperature (M.G. Jacko 1983. This latter parameter can be locally as high as 600 up to 1.500 ∘C depending on the brake type (M.G. Jacko 1983; Blau 2001. Thermal models have been developed to study interface effects at contacting surfaces (Majcherczak, Dufrenoy et al. 2007. Frictional energy can be dissipated through different mechanisms such as oxidation, rise in temperature, formation of wear particles, entropy changes associated to viscoelastic and viscoplastic deformation, and noise generation (Eddoumy, Addiego et al. 2011. Studies of friction brake show that more than 95% of the dissipated energy is transformed into heat (Kasem, Thevenet et al.; Majcherczak, Dufrenoy et al. 2007. Thermal analysis is therefore a primordial step in the study of brake systems since it provides thermo-mechanical properties (Majcherczak, Dufrenoy et al. 2007. The influence of the addition of metallic fibers on the performance of organic friction composites has been investigated using friction tests (Qu, Zhang et al. 2004. Benefits or limitations of the different fibers have been reported, however the issues of thermo-mechanical properties or effect of temperature on friction and wear behavior were not yet investigated (Bijwe, Kumar et al. 2008. No effort was done to correlate the thermo-mechanical and thermal properties with the friction and wear behavior. An important prerequisite is to get a good understanding on how brake materials behave. However, a link

  6. Effects of self-healing microcapsules on bending performance in composite brake pads

    Science.gov (United States)

    Zhang, Li; Dong, Xiu-ping; Wang, Hui

    2009-07-01

    For the purpose of reducing self-weight, friction noise and cost, improving shock absorption, enhancing corrosion and wear resistance, brake pads made of composite materials with self-healing function are prepared to substitute metal ones by designing ingredients and applying optimized production technology. As self-healing capsules are chosen, new method with technology of self-healing microcapsules, dicyclpentadiene (DCPD) microcapsules coated with poly (urea-formaldehyde), is put forward in this paper. In the crack's extending process, the stress is concentrated at the crack end, where the microcapsule is designed to be located. When the stress goes through the microcapsules and causes them to break, the self-healing liquid runs out to fill the crack by the capillary and it will poly-react with catalyst in the composite. As a result, the crack is healed. In this paper, polymer matrix composite brake pads with 6 prescriptions are prepared and studied. Three-point bending tests are carried out according to standards in GB/T 3356-1999 and the elastic constants of these polymer matrix composites are obtained by experiments. In accordance with the law of the continuous fiber composite, elastic constants of the short-fiber composite can be calculated by proportions of each ingredient. Results show that the theoretical expected results and the experimental values are consistent. 0.3-1.2 % mass proportion of microcapsules has little effects on the composite's bending intensity and modulus of elasticity. These studies also show that self-healing microcapsules used in composite brake pads is feasible.

  7. Influence of Optimizing Brake Pads Structure on Brake Disc Temperature and Thermal Stress%优化结构闸片对制动盘温度及热应力的影响

    Institute of Scientific and Technical Information of China (English)

    农万华; 符蓉; 韩晓明

    2012-01-01

    为了研究列车制动产生摩擦热对制动盘的耐热疲劳性能的影响,分析了摩擦热流分布与闸片结构的关系,提出一种优化闸片摩擦块固定位置,达到改善制动盘摩擦热分布的方法,采用有限元软件ABAQUS对优化前后的闸片制动过程进行了数值模拟,结果表明:与闸片优化前相比,闸片优化后制动盘最高温度和热应力分别下降的17%和23%,沿制动盘径向分布更均匀.%In order to study the effects of friction heat generation on thermal fatigue performance of brake disc during train braking, the relationship between friction heat flux distribution and brake pad structure was discussed , and a method of optimizing the brake pad friction blocks to improve the distribution of friction heat on brake disc was proposed. By finite element software ABAQUS, the braking process using the optimized brake pads and non-optimized brake pads was simulated respectively. The results show that the temperature of the optimized brake disc brake pads are decreased and the radial distribution of the thermal stress is more uniform along the brake disc. The results show thai compared with the brake pads before optimization, the highest temperature and thermal stress of the optimized brake discs brake pads are decreased by 17% and 23% respectively.

  8. 弹性盘型制动闸片装置振动特性研究%On Vibration Characteristics of Elastic Disc Brake Pad Device

    Institute of Scientific and Technical Information of China (English)

    杨宽; 张济民

    2013-01-01

    设计了一种新型的具有弹性的盘型制动闸片装置,建立了低速的轨道车辆弹性盘型制动的数学模型,与无弹性的制动闸片进行了单轴制动特性的动态仿真比较.仿真结果表明,具有弹性的闸片制动时同样能够保证车辆的制动性能;在制动盘或闸片摩擦面有缺陷时,弹性闸片能有效降低闸片与制动盘间摩擦力引起的振动.该设计为盘型制动系统的设计及分析提供了新的思路.%A new elastic disc brake pad device is designed, and a mathematical model on low speed railway vehicle e-lastic disc brake is established to compare with the non-elastic brake pad by single wheel-set braking simulation. The result shows that the elastic brake pad can guarantee the vehicle braking performance as same as the non-elastic brake pad. When the disc or the friction surface of brake pad has some defects, elastic brake pad can effectively reduce the friction and the vibration between the brake pad and the brake disc. The design has been proved to be correct and rational, it will provide new ideas for the design and analysis of the disc brake system.

  9. 49 CFR 393.47 - Brake actuators, slack adjusters, linings/pads and drums/rotors.

    Science.gov (United States)

    2010-10-01

    ... (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.47 Brake actuators... steering axle of a truck, truck-tractor or bus shall not be less than 4.8 mm (3/16 inch) at the shoe...

  10. A Factorial Design to Numerically Study the Effects of Brake Pad Properties on Friction and Wear Emissions

    Directory of Open Access Journals (Sweden)

    Jens Wahlström

    2016-01-01

    Full Text Available Airborne particulate emissions originating from the wear of pads and rotors of disc brakes contribute up to 50% of the total road emissions in Europe. The wear process that takes place on a mesoscopic length scale in the contact interfaces between the pads and rotors can be explained by the creation and destruction of contact plateaus. Due to this complex contact situation, it is hard to predict how changes in the wear and material parameters of the pad friction material will affect the friction and wear emissions. This paper reports on an investigation of the effect of different parameters of the pad friction material on the coefficient of friction and wear emissions. A full factorial design is developed using a simplified version of a previously developed cellular automaton approach to investigate the effect of four factors on the coefficient of friction and wear emission. The simulated result indicates that a stable third body, a high specific wear, and a relatively high amount of metal fibres yield a high and stable mean coefficient of friction, while a stable third body, a low specific wear, a stable resin, and a relatively high amount of metal fibres give low wear emissions.

  11. Bicycle Braking System

    OpenAIRE

    Brady, Noel

    2001-01-01

    A bicycle braking system for permitting controlled rotation and continuous power to the wheels of a bicycle during braking of the bicycle to enhance control of the bicycle during braking includes a cylindrical brake pad that is spring loaded within angled slots in a casing. The brake pad is positioned proximate the rim of a wheel and a cable assembly is coupled to the brake pad for urging the brake pad towards an end of the angled slots and against the rim of the wheel to slow rotation of the...

  12. Experiments on composites meant for making brake pads for the rolling stock

    Science.gov (United States)

    Socalici, A.; Pascu, L.; Ardelean, E.; Putan, V.

    2017-01-01

    For noise rail decrease and observance of the limits in UE rolling stock must be equipped with silent brake blocks of composite material to replace the conventional cast-iron blocks. For testing composite materials test pieces have been produced according to the characteristics of the experimental installation. The paper presents the laboratory experimentation phase on obtaining composite materials for brake blocks and wear behavior of the experimental test pieces.

  13. 乳胶粒化学改性酚醛树脂合成闸片的制动性能研究%Braking Performance of Hybrid Fibers Reinforced Brake Pad with Latex Particle Modified Phenolic Resin Binder

    Institute of Scientific and Technical Information of China (English)

    王海庆; 吴行阳; 周广荣; 丛培红

    2011-01-01

    A latex particle modified phenolic resin was designed and developed to manufacture organic brake pad for electric power locomotive brake. The braking performance was evaluated on a full - scale test bench at Vehicle Inspection Station of Product Quality Monitoring Center of Railway Ministry, People's Republic of China, according to the Europe standard UIC 541 - 3: 2006 and Standard of China Railway Ministry TB/T 3118 - 2005 ( the central line speed at brake pad was 41.8 m/s at the highest speed of 200 km/h ). The test results indicated that the average dry friction coefficient of the brake pad under different braking speeds ranged from 0.29 to 0.57, the average static friction coefficient was 0.47, and the wear rate of the pad was O. 2 cm3/MJ after 36 times of braking tests. All the above results satisfied the required values of UIC 541 -3: 2006. No bulges, loss of rubbing material, cracks and metal - embedded deposits were observed on the brake pad after the whole tests. FTIR analysis results indicated that chemical structure of the pad was similar to the polymer matrix, and no obvious tribochemical reactions were confirmed. All the results suggest that the new type organic brake pad may realize application for the brake of “Hexie” electric power locomotive.%采用自制的环保型乳胶粒化学改性酚醛树脂为粘结剂制备了和谐号电力机车用轮装式有机合成闸片,参照欧洲标准UIC 541-3:2006和我国铁道部标准TB/T 3118-2005规定的试验程序,在铁道部产品质量监督检验中心机车车辆检验站进行了闸片的制动性能试验(最高速度200 km/h时制动闸片中心线速度为41.8 m/s).试验结果表明该闸片在不同初始速度干燥条件下的平均摩擦系数在0.29~0.57,静摩擦系数平均值为0.47,36闸后的磨损率约为0.2 cm3/MJ,满足UIC 541-3:2006中规定的指标.表面形貌观察发现制动试验后闸片无开裂、掉渣、塌边和皴裂等现象,红外分析发现闸片摩擦

  14. Brake caliper with offset pads: Innovative brake technology for commercial vehicles offers opportunities to reduce weight and cost; Bremssattel mit tangential versetzten Bremsbelaegen: Innovative Radbremsentechnologie fuer Nutzfahrzeuge bietet neue Moeglichkeiten zur Gewichts- und Kostenreduzierung

    Energy Technology Data Exchange (ETDEWEB)

    Antony, P.; Blatt, P. [WABCO Radbremsen GmbH, Mannheim (Germany)

    2005-07-01

    Continuous optimizations and technical improvements showed no further potential for cost and weight reductions on basis of the conventional technique of a sliding caliper and two supported pads in the carrier. Additionally, global and technical needs are growing. With its 4th generation of air disc brakes and a new caliper concept, WABCO accounts to these developments. Characteristically for the New Generation (NG) is the caliper concept with pad offset in circumferential direction. This presentation describes construction and basics of the system, shows the usage of FEM and elements of Bionic methods and proofs its effectiveness with test bench results. Additional potential for the design of a new interfaces between brake and axle are identified. A significant improved disc cracking behavior offers possibilities for additional cost and weight savings. (orig.)

  15. Braking System for Wind Turbines

    Science.gov (United States)

    Krysiak, J. E.; Webb, F. E.

    1987-01-01

    Operating turbine stopped smoothly by fail-safe mechanism. Windturbine braking systems improved by system consisting of two large steel-alloy disks mounted on high-speed shaft of gear box, and brakepad assembly mounted on bracket fastened to top of gear box. Lever arms (with brake pads) actuated by spring-powered, pneumatic cylinders connected to these arms. Springs give specific spring-loading constant and exert predetermined load onto brake pads through lever arms. Pneumatic cylinders actuated positively to compress springs and disengage brake pads from disks. During power failure, brakes automatically lock onto disks, producing highly reliable, fail-safe stops. System doubles as stopping brake and "parking" brake.

  16. Simulation analysis for effect of pad lining arc on disc brake squeal%摩擦衬片包角对盘式制动器尖叫影响的仿真分析

    Institute of Scientific and Technical Information of China (English)

    张立军; 陈前银; 刁坤; 孟德建; 余卓平

    2016-01-01

    摩擦衬片包角对制动尖叫具有重要影响。针对某通风盘式制动器,建立有限元复模态模型并通过尖叫台架试验进行了正确性验证。基于该模型针对5种包角水平的摩擦衬片,通过仿真计算分析其对制动尖叫倾向性的影响,并从制动块自由模态特性、盘块间接触压力分布、不稳定模态频率及模态耦合特性角度解释了不同摩擦衬片包角对制动尖叫的影响机制。分析表明:摩擦衬片包角的改变会同时引起制动块结构特性变化和接触压力分布的变化,进而引起不稳定模态数量、频率和模态耦合特性的改变。%Lining arc of brake pad has a very important effect on disc brake squeal.A finite element complex analysis model of a ventilated disc brake was established and validated through a bench test of brake squeal.Based on this model,the influence of pad lining arc on brake squeal trend was investigated using simulation of disc brakes with pads of five lining arcs.At the same time,the influence mechanism was studied from view points of natural vibration characteristics of brake pad,pressure distribution between pad and disc,instable modal frequencies and modal coupling. It was shown that the structural characteristics and pressure distribution variations due to pad lining arc variations can cause the change of instable modes,modal frequencies and modal coupling.

  17. Heat distribution in disc brake

    Science.gov (United States)

    Klimenda, Frantisek; Soukup, Josef; Kampo, Jan

    2016-06-01

    This article is deals by the thermal analysis of the disc brake with floating caliper. The issue is solved by numerically. The half 2D model is used for solution in program ADINA 8.8. Two brake discs without the ventilation are solved. One disc is made from cast iron and the second is made from stainless steel. Both materials are an isotropic. By acting the pressure force on the brake pads will be pressing the pads to the brake disc. Speed will be reduced (slowing down). On the contact surface generates the heat, which the disc and pads heats. In the next part of article is comparison the maximum temperature at the time of braking. The temperatures of both materials for brake disc (gray cast iron, stainless steel) are compares. The heat flux during braking for the both materials is shown.

  18. Method and apparatus for electromagnetically braking a motor

    Science.gov (United States)

    Davis, Donald R. (Inventor); Radford, Nicolaus A (Inventor); Permenter, Frank Noble (Inventor); Parsons, Adam H (Inventor); Mehling, Joshua S (Inventor)

    2011-01-01

    An electromagnetic braking system and method is provided for selectively braking a motor using an electromagnetic brake having an electromagnet, a permanent magnet, a rotor assembly, and a brake pad. The brake assembly applies when the electromagnet is de-energized and releases when the electromagnet is energized. When applied the permanent magnet moves the brake pad into frictional engagement with a housing, and when released the electromagnet cancels the flux of the permanent magnet to allow a leaf spring to move the brake pad away from the housing. A controller has a DC/DC converter for converting a main bus voltage to a lower braking voltage based on certain parameters. The converter utilizes pulse-width modulation (PWM) to regulate the braking voltage. A calibrated gap is defined between the brake pad and permanent magnet when the brake assembly is released, and may be dynamically modified via the controller.

  19. 干摩擦条件下树脂刹车片磨损机制研究%Research on Wear Behavior of Resin Brake Pads under Dry Sliding

    Institute of Scientific and Technical Information of China (English)

    潘道元; 张育增; 刘健; 高中学; 王其兵

    2014-01-01

    To improve the wear resistance of resin brake pads made of resin and brass in the towing engine,the wear be-havior of Brass and Brass/Resin blends was investigated in the MPV-600 type abrasive wear tester under dry sliding.Worn morphology of the brake pad surface was observed using the stereo microscope in order to analyze the wear mechanism.Ex-perimental results show that the decrease in hardness and the change in wear mechanism because of the temperature rise caused by frictional heat are the main reason of the wear of resin brake pads under dry friction.Brass/Resin blends has better heat resistance and wear resistance than Brass sample.The friction coefficient of the friction pairs of resin brake pads and steel is mainly determined by copper mesh material.The wear mechanism is abrasive wear and oxidative wear for the friction pairs of Brass/Resin blends and 45 steel,and abrasive wear and abrasive wear for the friction pairs of brass and 45 steel under dry sliding.%为了优化拖缆机刹车部件的设计参数,同时进一步提高刹车片的耐磨性能,采用MPV-600型磨粒磨损试验机研究无石棉树脂摩擦片和黄铜试样与45#钢配副在干摩擦条件下的摩擦学性能,利用体式显微镜观察试样的磨损形貌并分析其磨损机制。结果表明:摩擦热引起的温升导致的硬度下降及磨损机制的改变是干摩擦条件下摩擦片磨损的主要原因;树脂刹车片的耐热性能、耐磨性能均好于黄铜试样,树脂刹车片与钢配副的摩擦因数主要是由树脂刹车片中的铜纤维材料决定的;干摩擦条件下树脂摩擦片的磨损机制是以磨粒磨损和氧化磨损为主,而黄铜试样以磨粒磨损和黏着磨损为主。

  20. 客车盘式制动器摩擦片前后磨损不均的分析%Analysis on Unbalanced Wear Between Front and Rear Brake Pads of Bus Disc Braker

    Institute of Scientific and Technical Information of China (English)

    汪桂金; 刘文虎; 孙克亮

    2015-01-01

    盘式制动器具有制动距离短、制动响应快、制动强度大、水稳定性强、散热性能好、结构紧凑、维修方便等优点,但在我国大中城市客车上的应用才刚刚开始。本文对城市客车前后桥采用盘式制动器造成的摩擦片磨损不均问题进行试验分析,找出问题原因,并提出相应的解决措施。%Disc brakers have the advantages of short braking distance, rapid response, excellent braking force, steady water performance, good heat distribution, compact installation and easy-to-repair, etc. Their applications on medium and large buses and coaches have just started in China. The authors mainly focus on the issue of unbalanced wear in braking pads between front and rear axles through testing analysis, and find out the main reasons, then state the corresponding solutions.

  1. 列车制动闸片接触界面接触压力分布研究%Research of the Contact Stress Distribution on the Contact Surface of the Train Brake Pad

    Institute of Scientific and Technical Information of China (English)

    陆超; 高诚辉; 黄健萌

    2013-01-01

    以列车盘式制动器为研究对象,建立一个三维瞬态热-结构耦合模型,利用有限元软件ABAQUS非线性多物理场耦合方法,数值模拟了制动过程,发现制动闸片上的温度场和接触应力场在接触界面呈不均匀分布,并且在每个闸块上二者存在着相互耦合的关系,温度高的区域由于热变形大、接触面积小,导致接触压力较高.此外,接触压力在制动过程中的变化还与摩擦力、减速移动热源有关.%It establishes the model for 3d transient thermal-structure coupling on the basis of brake disc of train.By using the finite element software ABAQUS,it simulates the braking process.The temperature field and contact stress field's distribution are not uniform on the contact face of the brake pad and they are coupled in each block.The higher temperature region which has larger thermal deformation leads to smaller contact area and higher contact pressure.The contact pressure is also related with friction and slow moving heat source in the braking process.

  2. 49 CFR 570.59 - Service brake system.

    Science.gov (United States)

    2010-10-01

    ... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY...-second of an inch over the fastener, or one-sixteenth of an inch over the brake shoe on bonded linings or... surface. Drum brake linings shall be securely attached to brake shoes. Disc brake pads shall be...

  3. Improved Electromagnetic Brake

    Science.gov (United States)

    Martin, Toby B.

    2004-01-01

    A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may

  4. 汽车盘式片热压成型方式的对比分析%Comparative Analysis of Automotive Brake Pads Thermoforming

    Institute of Scientific and Technical Information of China (English)

    李云鹏; 宫宝利; 杜宝程; 王铁山

    2013-01-01

    Three forming methods and press forming equipment of automotive disc pad in China are introduced in this paper, and test and analysis are made to the product made by those three forming methods. The results show that the density and compression ratio of the automotive disc pads formed with single-cylinder single chamber geometric pressure are superior to those made with other two forming methods, structural characteristics of a new type of disc pad developed based on specific pressure principle is introduced in the paper.%介绍了我国现有汽车盘式制动片的3种成型方式和压制成型设备,并针对这3种成型方式压制成型的产品进行了测试分析.结果表明,采用单缸单腔等比压压制方式成型的汽车盘式制动片,其密度和压缩率均优于另2种压制方式成型的产品.介绍了一种基于等比压原理研制的新型盘式制动片的结构特点.

  5. Research on Heat-Mechanical Coupling of Ventilated Disc Brakes under the Condition of Emergency Braking

    Science.gov (United States)

    Tan, Xuelong; Zhang, Jian; Tang, Wenxian; Zhang, Yang

    Taking the ventilated disc brake in some company as research object, and using UG to build 3D models of brake disc and pad, and making use of ABAQUS/Standard to set up two parts' finite element model, via the decelerated motion of actual simulation brake disc, which gets ventilated disc brake in the case of emergency breaking in time and space distribution of conditions of temperature and stress field, summarizes the distribution of temperature field and stress field, proves complex coupling between temperature, stress, and supplies the direct basis for brake's fatigue life analysis.

  6. Gravity brake

    Science.gov (United States)

    Lujan, Richard E.

    2001-01-01

    A mechanical gravity brake that prevents hoisted loads within a shaft from free-falling when a loss of hoisting force occurs. A loss of hoist lifting force may occur in a number of situations, for example if a hoist cable were to break, the brakes were to fail on a winch, or the hoist mechanism itself were to fail. Under normal hoisting conditions, the gravity brake of the invention is subject to an upward lifting force from the hoist and a downward pulling force from a suspended load. If the lifting force should suddenly cease, the loss of differential forces on the gravity brake in free-fall is translated to extend a set of brakes against the walls of the shaft to stop the free fall descent of the gravity brake and attached load.

  7. Magnetostrictive Brake

    Science.gov (United States)

    Diftler, Myron A.; Hulse, Aaron

    2010-01-01

    A magnetostrictive brake has been designed as a more energy-efficient alternative to a magnetic fail-safe brake in a robot. (In the specific application, failsafe signifies that the brake is normally engaged; that is, power must be supplied to allow free rotation.) The magnetic failsafe brake must be supplied with about 8 W of electric power to initiate and maintain disengagement. In contrast, the magnetostrictive brake, which would have about the same dimensions and the same torque rating as those of the magnetic fail-safe brake, would demand only about 2 W of power for disengagement. The brake (see figure) would include a stationary base plate and a hub mounted on the base plate. Two solenoid assemblies would be mounted in diametrically opposed recesses in the hub. The cores of the solenoids would be made of the magnetostrictive alloy Terfenol-D or equivalent. The rotating part of the brake would be a ring-and spring- disk subassembly. By means of leaf springs not shown in the figure, this subassembly would be coupled with the shaft that the brake is meant to restrain. With no power supplied to the solenoids, a permanent magnet would pull axially on a stepped disk and on a shelf in the hub, causing the ring to be squeezed axially between the stepped disk and the hub. The friction associated with this axial squeeze would effect the braking action. Supplying electric power to the solenoids would cause the magnetostrictive cylinders to push radially inward against a set of wedges that would be in axial contact with the stepped disk. The wedges would convert the radial magnetostrictive strain to a multiplied axial displacement of the stepped disk. This axial displacement would be just large enough to lift the stepped disk, against the permanent magnetic force, out of contact with the ring. The ring would then be free to turn because it would no longer be squeezed axially between the stepped disk and the hub.

  8. Frictional Performance and Temperature Rise of a Mining Nonasbestos Brake Material during Emergency Braking

    Directory of Open Access Journals (Sweden)

    Jiusheng Bao

    2015-01-01

    Full Text Available By simulating emergency braking conditions of mine hoisters, tribological experiments of a mining nonasbestos brake material sliding on E355CC steel friction disc investigated a pad-on-disc friction tester. It is shown that, under combined influence of braking velocity and pressure, the lubricating film and micro-convex-apices on wear surface would have complex physicochemical reactions which make the instant friction coefficient rise gradually while the instant surface temperature rises first and then falls. With the antifriction effect from lubricating film and the desquamating of composite materials, the mean friction coefficient decreases first, then rises, and decreases again with the increasing of initial braking velocity. And with the existence of micro-convex-apices and variation from increment ratio of load and actual contacting area, it rises first and then falls with the increasing of braking pressure. However, the mean surface temperature rises obviously with the increasing of both initial braking velocity and braking pressure for growth of transformed kinetic energy. It is considered that the friction coefficient cannot be considered as a constant when designing brake devices for mine hoisters. And special attention should be paid to the serious influence of surface temperature on tribological performance of brake material during emergency braking.

  9. Squeal noise in simple numerical brake models

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-09-01

    Since the early 1920s, automotive disc brake squeal has caused warranty issues and customer dissatisfaction. Despite a good deal of progress achieved, predicting brake squeal propensity is as difficult as ever as not all mechanisms and interactions are known owing to their highly fugitive complex nature. In recent years, research has been focused on the prediction of unstable vibration modes by the complex eigenvalue analysis (CEA) for the mode-coupling type of instability. There has been very limited consideration given to the calculation of the acoustic radiation properties due to friction contact between a pad and a rotor. Recent analyses using a forced response analysis with harmonic contact pressure excitation indicates negative dissipated energy at some pad eigenfrequencies predicted to be stable by the CEA. A transient nonlinear time domain analysis with no external excitation indicates that squeal could develop at these eigenfrequencies. Here, the acoustic radiation characteristics of those pad modes are determined by analysing the acoustic power levels and radiation efficiencies of simplified brake models in the form of a pad rubbing on a plate or on a disc using the acoustic boundary element method based on velocities extracted from the forced response analysis. Results show that unstable pad modes trigger unstable disc vibrations resulting in instantaneous mode squeal similar to those observed experimentally. Changes in the radiation efficiency with pressure variations are smaller than those with friction coefficient variations and are caused by the phase difference of the velocities out-of-plane vibration between the pad and the disc.

  10. Thermo-mechanical behaviour of heavy-duty disc brake systems

    OpenAIRE

    Chen, J. P.

    2001-01-01

    In heavy-duty disc brake systems, braking is a transient, non-linear and asymmetrical thermo-mechanical process. Surface cracking, rather than wear, is the major factor limiting the brake disc's life. The disc material (cast-iron), heat transfer boundary conditions and pad-disc frictional reactions are characteristically non-linear and asymmetrical during the friction process. Non-uniform deformation and surface cracks in brake discs result from the accumulation of excess...

  11. Emergency braking : research summary.

    NARCIS (Netherlands)

    Schlösser, L.H.M.

    1976-01-01

    This report deals with an investigation concerning braking capacity of trucks if somewhere a failure occurs in the normal service brake. Purpose of research was to get an insight in various secondary braking systems for trucks. It is shown that with almost all of the secondary braking system it was

  12. Wear Modalities and Mechanisms of the Mining Non-asbestos Composite Brake Material

    Science.gov (United States)

    Bao, Jiusheng; Yin, Yan; Zhu, Zhencai; Tong, Minming; Lu, Yuhao; Peng, Yuxing

    2013-08-01

    The mining brake material is generally made of composite materials and its wear has important influences on the braking performance of disc brakes. In order to improve the braking reliability of mine hoisters, this paper did some tribological investigations on the mining brake material to reveal its wear modalities and mechanisms. The mining non-asbestos brake shoe and 16Mn steel were selected as braking pairs and tested on a pad-on-disc friction tester. And a SEM was used to observe the worn surface of the brake shoe. It is shown that the non-asbestos brake material has mainly five wear modalities: adhesive wear, abrasive wear, cutting wear, fatigue wear and high heat wear. At the front period of a single braking the wear modality is mainly composed of some light mechanical wear such as abrasive, cutting and point adhesive. With the temperature rising at the back period it transforms to some heavy mechanical wear such as piece adhesive and fatigue. While in several repeated brakings once the surface temperature rises beyond the thermal-decomposition point of the bonding material, the strong destructive high heat wear takes leading roles on the surface. And a phenomenon called friction catastrophe (FC) occurs easily, which as a result causes a braking failure. It is considered that the friction heat has important influences on the wear modalities of the brake material. And the reduction of friction heat must be an effective technical method for decreasing wear and avoiding braking failures.

  13. Nonlinear transient and chaotic interactions in disc brake squeal

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-04-01

    In automotive disc-brake squeal, most numerical studies have been focussed on the prediction of unstable vibration modes in the frequency domain using the complex eigenvalue analysis. However, the magnitude of the positive real part of a complex eigenvalue is an unreliable indicator of squeal occurrence. Although nonlinearities have been shown to play a significant role in brake squeal, transient nonlinear time domain analyses have rarely been applied owing to high computational costs. Here the complex eigenvalue analysis, the direct steady-state analysis and the transient nonlinear time domain analysis are applied to an isotropic pad-on-disc finite element model representing a simple model of a brake system. While in this investigation, in-plane pad-mode instabilities are not detected by the complex eigenvalue analysis, the dissipated energy obtained by the direct steady-state analysis of the model subjected to harmonic contact pressure excitation is negative at frequencies of pad modes, indicating a potential for instabilities. Transient nonlinear time domain analysis of the pad and disc dynamics reveal that in-plane pad vibrations excite a dominant out-of-plane disc mode. For intermittently chaotic pad motion, the disc dynamics is quasi-periodic; and for chaotic motion of the pad, a toroidal attractor is found for the disc's out-of-plane motion. Nonlinear interactions between the pad and the disc highlight that different parts in a brake system display different dynamic behaviour and need to be analysed separately. The type II intermittency route to chaos could be the cause for the experimentally observed instantaneous mode squeal.

  14. Squeal analysis of ventilated disc brake using ansys

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Naser, Ahmed; Allam, Essam; Abouel-seoud, Shawki [Automotive and Tractors Engineering Department., Faculty of Engineering, Helwan University, Cairo (Egypt); Ahmed, Ibrahim; Allam, Sabry [Automotive and Tractors Technology Department, Faculty of Industrial Education, Helwan University, Cairo (Egypt)

    2012-07-01

    It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver) used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI) for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  15. Squeal analysis of ventilated disc brake using ansys

    Directory of Open Access Journals (Sweden)

    Ahmed Abdel-Naser, Ibrahim Ahmed, Essam Allam, Sabry Allam, Shawki Abouel-seoud

    2012-01-01

    Full Text Available It is well-known that automobile brakes can generate several kinds of noises. Among them is squeal, a noise in the 1-15 kHz range. It is commonly accepted that brake squeal is initiated by instability due to the friction forces, leading to self excited vibrations. To predict the onset of brake instability, a modal analysis of the prestressed structure can be performed on an improved dynamic finite element model of ventilated disc brake with friction coupling. An unsymmetric stiffness matrix is a result of the friction coupling between the brake pad and disc; this may lead to complex eigenfrequencies. The complex eigenvalue method (Unsymmetric solver used to analyse mode shapes associated with the predicted natural frequency. Creating the element of Matrix27 between the ventilated disc and pad was very important in studying the squeal of the coupled ventilated disc brake. The results demonstrated that the FEM for the coupled ventilated rotor and pad showed a good interaction between the non-linear contact and the linear modal analysis. Furthermore, the unsymmetric solver showed that the modes of the coupled disc-pad contained two types of mode. The first type was normal mode, which did not contain an imaginary part while the second type was complex mode that contained real and imaginary parts. Moreover, complex eigenvalue analysis predicted always more unstable modes than the number of squeal frequencies that really occur in the brake system. The maximum squeal index was observed at mode 16 and at frequency of 4083 Hz with instability of 480 sec-1. However; the tendency of instability (TOI for the system at contact stiffness of 1 GN/m was 59 that gave the lowest instability of the system.

  16. Safety Braking System

    Directory of Open Access Journals (Sweden)

    Joseph Charles

    2016-10-01

    Full Text Available Now a day's accidents due to brake failure are increasing in a high margin, so safety has acquired a greater priority. In order to control this sudden brake failures we have modified the conventional braking systems in automobiles by adding an extra safety brake to the engine shaft. The idea of the work is to improve the safety parameters regarding the brakes. Engagement of the secondary brake without the assistance of driver is an advantage for this system. As it would make the vehicle to stop without any lag. A Hall effect sensor is used to detect the motion of wheel by noting the magnetic field. The signals given out from the sensor directs the microcontroller to operate the relay and hence to actuate the solenoid and thereby actuating the secondary brake.

  17. Optical classification for quality and defect analysis of train brakes

    Science.gov (United States)

    Glock, Stefan; Hausmann, Stefan; Gerke, Sebastian; Warok, Alexander; Spiess, Peter; Witte, Stefan; Lohweg, Volker

    2009-06-01

    In this paper we present an optical measurement system approach for quality analysis of brakes which are used in high-speed trains. The brakes consist of the so called brake discs and pads. In a deceleration process the discs will be heated up to 500°C. The quality measure is based on the fact that the heated brake discs should not generate hot spots inside the brake material. Instead, the brake disc should be heated homogeneously by the deceleration. Therefore, it makes sense to analyze the number of hot spots and their relative gradients to create a quality measure for train brakes. In this contribution we present a new approach for a quality measurement system which is based on an image analysis and classification of infra-red based heat images. Brake images which are represented in pseudo-color are first transformed in a linear grayscale space by a hue-saturation-intensity (HSI) space. This transform is necessary for the following gradient analysis which is based on gray scale gradient filters. Furthermore, different features based on Haralick's measures are generated from the gray scale and gradient images. A following Fuzzy-Pattern-Classifier is used for the classification of good and bad brakes. It has to be pointed out that the classifier returns a score value for each brake which is between 0 and 100% good quality. This fact guarantees that not only good and bad bakes can be distinguished, but also their quality can be labeled. The results show that all critical thermal patterns of train brakes can be sensed and verified.

  18. Guidelines for numerical vibration and acoustic analysis of disc brake squeal using simple models of brake systems

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.; Marburg, S.

    2013-04-01

    Brake squeal has become of increasing concern to the automotive industry but guidelines on how to confidently predict squeal propensity are yet to be established. While it is standard practice to use the complex eigenvalue analysis to predict unstable vibration modes, there have been few attempts to calculate their acoustic radiation. Here guidelines are developed for numerical vibration and acoustic analysis of brake squeal using models of simplified brake systems with friction contact by considering (1) the selection of appropriate elements, contact and mesh; (2) the extraction of surface velocities via forced response; and (3) the calculation of the acoustic response itself. Results indicate that quadratic tetrahedral elements offer the best option for meshing more realistic geometry. A mesh has to be sufficiently fine especially in the contact region to predict mesh-independent unstable vibration modes. Regarding the vibration response, only the direct, steady-state method with a pressurised pad and finite sliding formulation (allowing contact separation) should be used. Comparison of different numerical methods suggest that a obroadband fast multi-pole boundary element method with the Burton-Miller formulation would efficiently solve the acoustic radiation of a full brake system. Results also suggest that a pad lift-off can amplify the acoustic radiation similar to a horn effect. A horn effect is also observed for chamfered pads which are used in practice to reduce the number and strength of unstable vibration modes. These results highlight the importance of optimising the pad shape to reduce acoustic radiation of unstable vibration modes.

  19. Brake Fundamentals. Automotive Articulation Project.

    Science.gov (United States)

    Cunningham, Larry; And Others

    Designed for secondary and postsecondary auto mechanics programs, this curriculum guide contains learning exercises in seven areas: (1) brake fundamentals; (2) brake lines, fluid, and hoses; (3) drum brakes; (4) disc brake system and service; (5) master cylinder, power boost, and control valves; (6) parking brakes; and (7) trouble shooting. Each…

  20. Muzzle brakes and their performance

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1958-01-01

    Full Text Available A criteria for the usefulness of a muzzle brake on any equipment is discussed and applied to existing weapons. Efficiencies of the existing muzzle brakes are also calculated. Design considerations for a muzzle brake are summarized.

  1. ENERGY-LOADING OF DISKS IN FRICTION PAIRS OF “DISC-PAD” OF BRAKING DEVICES IN VEHICLES (part two

    Directory of Open Access Journals (Sweden)

    Krasin P. S.

    2015-06-01

    Full Text Available In the materials of the article we mention the regularities of changes in the volume and surface solid temperature gradients and self-ventilated brake discs and illustrate their impact on the main operating parameters of the friction pairs of disk-to-pad brakes of the A 172 bus; the relationship between thermo-physical parameters of polished and matte surfaces with areas of brake discs of various types. The influence of the type of tests on the pairs of loaded with energy friction disk and pad brakes of the vehicle. We have set the intensity of heat exchange processes from the surfaces of the brake discs of various types. It is shown that this leads to increased surface temperature gradient. The volume and the surface temperature gradients of the brake discs were determined with the involvement of the hypothesis of summation of temperatures on the surface when you post the generated electric currents. It was found that in the surface layer of the working surface of a solid brake disc at its pulse heating under the influence of the temperature of the flash nucleate cracks due to the thermal fatigue of the material of the disk. The features of the design of the brake discs were considered as well. On the basis of the calculation and the experimental data we have shown a correlation between the emissivity of brushed and polished surfaces and their areas in the disk-to-pad brakes when using solid and self-ventilated discs

  2. 14 CFR 25.735 - Brakes and braking systems.

    Science.gov (United States)

    2010-01-01

    ... (ii) Allow the pilot(s) to override the system by use of manual braking. (d) Parking brake. The airplane must have a parking brake control that, when selected on, will, without further attention, prevent... be indication in the cockpit when the parking brake is not fully released. (e) Antiskid system. If...

  3. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    Directory of Open Access Journals (Sweden)

    Dong-Chan Lee

    2015-11-01

    Full Text Available A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installation space and reducing financial budget costs. Since the brake caliper has a high nonlinearity, such as hysteresis resulting from friction and from the precompressed spring of the brake cylinder, we measured the hysteresis of the brake caliper clamping force for a mechanical brake system using loadcells, based on which a mathematical model was constructed for the hysteresis of the clamping force between the brake pad and the disk. Moreover, the pneumatic cylinder dynamics are identified and are implemented in three air tanks, together with hysteresis nonlinearity. The proposed brake hardware-in-the-loop simulation system is applied to the wheel-slide protection simulation of a railway vehicle with an initial speed of 80 km/h and demonstrated experimentally accounting for the hysteresis and brake cylinder dynamics.

  4. Development of hydraulic brake actuator for active brake control; Active brake seigyoyo yuatsu booster no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, Y.; Hattori, M. Sugisawa, M.; Nishii, M. [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    Recently, application of active brake control systems of the vehicle are increasing. (Vehicle stability control, Panic brake assist ) We have developed a new hydraulic brake actuator for active brake control systems. New hydraulic brake actuator is composed of the three parts. (Hydraulic booster unit, Power supply unit, Control valve unit) This report describes the construction of the new hydraulic booster unit. 2 refs., 10 figs.

  5. Thermomechanical behavior of dry contacts in disc brake rotor with a grey cast iron composition

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2013-01-01

    Full Text Available The main purpose of this study is to analysis the thermomechanical behavior of the dry contact between the brake disc and pads during the braking phase. The simulation strategy is based on the calculation code ANSYS11. The modeling of transient temperature in the disk is actually used to identify the factor of geometric design of the disk to install the ventilation system in vehicles. The thermal-structural analysis is then used coupling to determine the deformation established and the Von Mises stresses in the disk, the contact pressure distribution in pads. The results are satisfactory compared to those found in the literature.

  6. Product and process innovation of grey cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Schorn, M. [Brembo S.P.A. (Italy)

    2006-07-01

    The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

  7. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    OpenAIRE

    Adam Polak; Janusz Grzybek

    2005-01-01

    The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis o...

  8. Compositions, Functions, and Testing of Friction Brake Materials and Their Additives

    Energy Technology Data Exchange (ETDEWEB)

    Blau, PJ

    2001-10-22

    The purpose of this report is to present a survey of commercial brake materials and additives, and to indicate their typical properties and functions, especially as regards their use in heavy trucks. Most truck pad and shoe materials described here were designed to wear against cast iron. Brake material test methods are also briefly described. This report does not address issues associated with the fabrication and manufacturing of brake materials. Since there are literally thousands of brake material additives, and their combinations are nearly limitless, it is impractical to list them all here. Rather, an attempt has been made to capture the primary constituents and their functions. An Appendix contains thermo-physical properties of some current and potential brake materials.

  9. Braking System Modeling and Brake Temperature Response to Repeated Cycle

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2014-12-01

    Full Text Available Braking safety is crucial while driving the passenger or commercial vehicles. Large amount of kinetic energy is absorbed by four brakes fitted in the vehicle. If the braking system fails to work, road accident could happen and may result in death. This research aims to model braking system together with vehicle in Matlab/Simulink software and measure actual brake temperature. First, brake characteristic and vehicle dynamic model were generated to estimate friction force and dissipated heat. Next, Arduino based prototype brake temperature monitoring was developed and tested on the road. From the experiment, it was found that brake temperature tends to increase steadily in long repeated deceleration and acceleration cycle.

  10. Numerical investigation of a three-dimensional disc-pad model with and without thermal effects

    Directory of Open Access Journals (Sweden)

    Belhocine Ali

    2015-01-01

    Full Text Available This study aims to identify thermal effects in the structure and the contact behavior of a disc-pad assembly using a finite element approach. The first analysis is performed on the disc-pad model in the absence of thermal effects. The structural performance of the disc-pad model is predicted in terms of factors such as the deformation and Von Mises stress. Next, thermomechanical analysis is performed on the same disc-pad model with the inclusion of convection, adiabatic, and heat flux elements. The predicted temperature distribution, deformation, stress, and contact pressure are presented. The structural performance between the two analyses (mechanical and thermomechanical is compared. This study can assist brake engineers in choosing a suitable analysis method to critically evaluate the structural and contact behavior of the disc brake assembly.

  11. 49 CFR 393.52 - Brake performance.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Brake performance. 393.52 Section 393.52... NECESSARY FOR SAFE OPERATION Brakes § 393.52 Brake performance. (a) Upon application of its service brakes... braking force is measured by a performance-based brake tester which meets the requirements of...

  12. Sports-related pads.

    Science.gov (United States)

    Dickens, Rio; Adams, Brian B; Mutasim, Diya F

    2002-05-01

    Knuckle pads, first described by Garrod in 1893, 1 are benign, asymptomatic, well- circumscribed, smooth, firm, skin colored papules, nodules, or plaques. They most commonly occur on the dorsal aspect of the proximal interphalangeal joint of the finger, 2 but also may occur on the dorsal aspects of the foot over joints. 3-5 Knuckle pads may be inherited or acquired. 1 While some authors suggest that trauma is not a significant factor, 6 acquired knuckle pads have been associated with repetitive friction and trauma, 2,7 and may resemble athlete's nodules (also referred to as collagenomas). 1 Histologically, knuckle pads are characterized by hyperkeratosis, hypergranulosis, proliferation of fibroblasts and capillaries, and thickened and irregular collagen bundles. 1 Few cases of knuckle pads involving the lower extremities have been reported. 7 Knuckle pads of the feet have been described in association with inherited syndromes, such as acrokeratoelastoidosis Costa, 3 a syndrome of knuckle pads, leukonychia and deafness, 4 and a syndrome of knuckle pads, leukonychia, deafness and keratosis palmoplantaris. 5 We report a case that illustrates an unusual presentation of acquired knuckle pads of the feet secondary to repetitive friction from athletic gear.

  13. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    Science.gov (United States)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  14. Analysis on Partial Friction Phenomenon of the Brake Disc for High-speed Train Brake%高速列车刹车片偏摩现象的研究

    Institute of Scientific and Technical Information of China (English)

    阎树田; 邹本涛; 高升

    2013-01-01

    Thermal structural coupled finite element method of brake pads for high speed train was given in this paper,calculate the boundary conditions, the finite element numerical simulation of brake pads was done by ABAQUS software and and make detailed analysis research of partial friction phenomenon for Brake pads.%研究了高速列车刹车片的热结构耦合有限元求解方法,确定其边界条件,利用ABAQUS软件对刹车片进行有限元数值模拟,并做了较为详细的分析研究,在此基础上分析了盘式制动器刹车片的偏摩现象.

  15. Research of Motorcycle Braking Parameters

    Directory of Open Access Journals (Sweden)

    Loreta Levulytė

    2016-12-01

    Full Text Available From a technical point of view, in dangerous or emergency situation is very important motorcycle driver reaction and vehicle braking time. Motor-cycle deceleration parameters depend not only on the motorcycle brake system, but also on the driving experience. A significant influence on decel-eration the motorcycle has aerodynamic parameters, pavement type and condition, as well as the technical condition of the motocycle, shock absorb-ers, tire type and their technical condition. This article provides an analysis of the motorcycle longitudinal deceleration, braking modes of the mo-torcycle on a dry asphalt road surface. Motorcycle stopping – deceleration – acceleration efficiency issue, stopping in different modes. First ana-lyzed the dynamics of a motorcycle deceleration braking only the front wheel, then braked front and rear wheels and complex – then braked the front and rear wheels at the same time. The goal of experimental study is to determine the influence of braking modes intense fir motorcycle brak-ing deceleration when braking on dry road pavement, at three different braking modes, and set the braking path of change. Motorcycle decelera-tion in the longitudinal direction is an important parameter for analysis traffic accidents, for accident reconstruction process and the examination of motorcyclists technical possibility to avoid an accident.

  16. Tribomaterial factors in space mechanism brake performance

    Science.gov (United States)

    Hawthorne, H. M.

    1990-01-01

    The asbestos/phenolic pads of Shuttle Remote Manipulator System (SRMS) brakes are unsuitable for use in long life space mechanisms because their friction decreases on extended sliding in high vacuum. Dehydration of the material and accumulation of wear debris in the conforming interface of this tribosystem induces the permanent friction changes. Other polymer and some ceramic based materials exhibit similar frictional torque behavior due to the development of minimal contact patches by the interfacial debris. In contrast, high friction occurs when other ceramics form many small contacts throughout fine debris beds. Generating this latter interfacial structure during run-in ensures that the in-vacuo friction remains stable thereafter. Such materials with low wear rates are potential candidates for friction elements in SSRMS and similar mechanisms.

  17. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: Interim results

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, David M., E-mail: davidb@itox.ch [Consultant in Toxicology, 1208 Geneva (Switzerland); Rogers, Rick, E-mail: rarogers5@yahoo.com [Rogers Imaging, Needham, MA 02494 (United States); Sepulveda, Rosalina [Rogers Imaging, Needham, MA 02494 (United States); Kunzendorf, Peter, E-mail: Peter.Kunzendorf@GSA-Ratingen.de [GSA Gesellschaft für Schadstoffanalytik mbH, D-40882 Ratingen (Germany); Bellmann, Bernd [Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625 Hannover (Germany); Ernst, Heinrich, E-mail: Heinrich.ernst@item.fraunhofer.de [Fraunhofer Institute for Toxicology and Experimental Medicine, D-30625 Hannover (Germany); Phillips, James I., E-mail: jim.phillips@nioh.nhls.ac.za [National Institute for Occupational Health, National Health Laboratory Service (South Africa); Department of Biomedical Technology, Faculty of Health Sciences, University of Johannesburg (South Africa)

    2014-04-01

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T{sub 1/2} estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T{sub 1/2} > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d.

  18. The Comparative Analysis and Evaluation of Ecological Characteristics of Drum and Disk Wheel Brakes

    Directory of Open Access Journals (Sweden)

    Aleksandr Revin

    2011-04-01

    Full Text Available It is well-known that automobile transport as well as industry are the main sources of air pollution. In addition to exhaust gases, the flow of traffic releases a cloud of dust, consisting of over 60% of micro- and ultramicroscopic particles with radius of 10.0–0.25 µm, which are formed due to wheel abrasion (caused by the road grip of a tyre and the use of the brake blocks (in braking. The products formed in the process of wearing of the wheel brake pads are also the sources of the mass of fine dispersed particles over an urban highway. The authors analyse and evaluate ecological characteristics of drum and disk wheel brakes of vehicles.Article in Russian

  19. Control of Braking Noise of A Car Disc Brake%某型轿车盘式制动器制动噪声的控制

    Institute of Scientific and Technical Information of China (English)

    戢何民

    2011-01-01

    Bench test is made to a car diac brake, it is found in this test that braking noise frequency mainly occurs at 3 kHz. With FEA, vibration characteristic analysis is made to brake disc, brake caliper case, caliper bracket and friction pad. Test results indicate that 7-order vibration mode of brake caliper bracket is a major contributor of -braking noise. Structure of brake caliper bracket is modified, and bench test is made to the disc brake with the modified caliper bracket. The results show that cold state braking noise is reduced from 100.5 dB to 73.4 dB, meeting the requirement of noise limit of this vehicle.%对某型轿车盘式制动器进行了台架试验,发现该制动器主要制动噪声频率在3 kHz附近.采用有限元FEA分析手段对制动盘、制动钳壳体、制动钳支架和摩擦片进行了振动特性分析.结果表明,制动钳支架的7阶振动模态是导致制动噪声产生的原因之一.对制动钳支架结构设计进行了改进,并对装有改进后制动钳支架的盘式制动器进行了台架试验.结果表明,制动器冷态制动噪声从100.5 dB下降为73.4 dB,达到了该车型对制动器噪声的限值要求.

  20. Structural and Contact Analysis of a 3-Dimensional Disc-Pad Model with and without Thermal Effects

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-12-01

    Full Text Available The motivation of this work is to identify thermal effects on the structural and contact behaviour of a disc-pad assembly using a finite element approach. The first analysis is performed on the disc-pad model without the presence of thermal properties. Structural performance of the disc-pad model such as deformation and Von Mises stress is predicted. Next, thermomechanical analysis is performed on the same disc-pad model with the inclusion of convection, adiabatic and heat flux elements. The prediction results of temperature distribution, deformation, stress and contact pressure are presented. Comparison of the structural performance between the two analyses (mechanical and thermomechanical is also made. From this study, it can assist brake engineers to choose a suitable analysis in order to critically evaluate structural and contact behaviour of the disc brake assembly.

  1. Clutches and brakes design and selection

    CERN Document Server

    Orthwein, William C

    2004-01-01

    FRICTION MATERIALSFriction CodeWearBrake FadeFriction MaterialsNotationReferencesBAND BRAKESDerivation of EquationsApplicationLever-Actuated Band Brake: Backstop DesignExample: Design of a BackstopNotationFormula CollectionReferencesEXTERNALLY AND INTERNALLY PIVOTED SHOE BRAKESPivoted External Drum BrakesPivoted Internal Drum BrakesDesign of Dual-Anchor Twin-Shoe Drum BrakesDual-Anchor Twin-Shoe Drum Brake Design ExamplesDesign of Single-Anchor Twin-Shoe Drum BrakesSingle-Anchor Twin-Shoe Drum Brake Design Exam

  2. iPad portable genius

    CERN Document Server

    McFedries, Paul

    2013-01-01

    Make the most of your iPad with these savvy tips and techniques The iPad, iPad Air, and iPad mini are taking the world by storm. This no-nonsense guide covers everything you want to know to take full advantage of all your iPad has to offer. Along with necessary basics about the newest iPad; iPad Air, iPad mini; and iOS; it gives you smart; innovative ways to accomplish a variety of tasks and tips to help you maximize the convenience of your Apple digital lifestyle. More than 100 million iPads have been sold; and the number continues to growHip and practical; Portable Genius guides are packed

  3. An analysis of braking measures

    NARCIS (Netherlands)

    De Groot, S.; De Winter, J.C.F.; Wieringa, P.A.; Mulder, M.

    2010-01-01

    Braking to a full stop at a prescribed target position is a driving manoeuvre regularly used in experiments to investigate driving behaviour or to test vehicle acceleration feedback systems in simulators. Many different performance measures have been reported in the literature for analysing braking.

  4. Fireproof Brake Hydraulic System.

    Science.gov (United States)

    1981-09-01

    bulk modulus and density are the same (see Table 2). AO-2 is the base stock fluid for AO-8 which is a blend of AO-2 and a viscosity index (VI) improver...RADIANS LI+ BRAK .. .... " 17 . 3000 4 BRAKE .~1~~ 4~~I 4 4 4- 4 .! L 3 00 00i- FTLB 0 ’ 25 00 +--- + + i DISPCE EN FiueE4 raeSse taiiy tndr ytm...VA LVE ... it .. . . .. . F... .. igur E. 8 Brak Syste Stability...... .. .. .. .. Tw-FuRRSstNTer Daming Amit 327. .. .. .. .... APPENDIX F

  5. Treating P.A.D.

    Science.gov (United States)

    ... Issue Past Issues Special Section Treating P.A.D. Past Issues / Summer 2008 Table of Contents For ... Illustration courtesy of NHLBI Treatment for P.A.D. is designed to reduce a patient's symptoms, prevent ...

  6. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  7. 完美iPad

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    之前,大家对苹果iPad总有各种各样的抱怨,iPad4太重,iPad Min的屏幕太粗糙等等。当iPad Air和iPad mini Retina版推出之后,让大家焦虑的是两者选择谁的问题了。

  8. 49 CFR 238.231 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... by testing or previous service. (h) Hand brakes and parking brakes. (1) Except for a locomotive that..., and except for MU locomotives, all locomotives shall be equipped with a hand or parking brake that can... locomotives, on locomotives so equipped, the hand or parking brake as well as its parts and connections...

  9. 49 CFR 238.431 - Brake system.

    Science.gov (United States)

    2010-10-01

    ... thermal damage to wheels or discs. (f) The brake system design shall allow a disabled train's pneumatic... 49 Transportation 4 2010-10-01 2010-10-01 false Brake system. 238.431 Section 238.431... Equipment § 238.431 Brake system. (a) A passenger train's brake system shall be capable of stopping...

  10. Transient switching control strategy from regenerative braking to anti-lock braking with a semi-brake-by-wire system

    Science.gov (United States)

    Li, Liang; Li, Xujian; Wang, Xiangyu; Liu, Yahui; Song, Jian; Ran, Xu

    2016-02-01

    Regenerative braking is an important technology in improving fuel economy of an electric vehicle (EV). However, additional motor braking will change the dynamic characteristics of the vehicle, leading to braking instability, especially when the anti-lock braking system (ABS) is triggered. In this paper, a novel semi-brake-by-wire system, without the use of a pedal simulator and fail-safe device, is proposed. In order to compensate for the hysteretic characteristics of the designed brake system while ensure braking reliability and fuel economy when the ABS is triggered, a novel switching compensation control strategy using sliding mode control is brought forward. The proposed strategy converts the complex coupling braking process into independent control of hydraulic braking and regenerative braking, through which a balance between braking performance, braking reliability, braking safety and fuel economy is achieved. Simulation results show that the proposed strategy is effective and adaptable in different road conditions while the large wheel slip rate is triggered during a regenerative braking course. The research provides a new possibility of low-cost equipment and better control performance for the regenerative braking in the EV and the hybrid EV.

  11. Brake Stops Both Rotation And Translation

    Science.gov (United States)

    Allred, Johnny W.; Fleck, Vincent J., Jr.

    1995-01-01

    Combination of braking and positioning mechanisms allows both rotation and translation before brake engaged. Designed for use in positioning model airplane in wind tunnel. Modified version used to position camera on tripod. Brake fast and convenient to use; contains single actuator energizing braking actions against both rotation and translation. Braking actuator electric, but pneumatic actuator could be used instead. Compact and lightweight, applies locking forces close to load, and presents minimal cross section to airflow.

  12. The mechanism of changes in the surface layer of grey cast iron automotive brake disc

    Directory of Open Access Journals (Sweden)

    Adam Polak

    2005-12-01

    Full Text Available The aim of the study was to create a model, describing the run of tribological processes in the surface layer of grey cast iron automotive brake discs. Grey cast iron discs mating with non-asbestos organic brake pads were chosen for the investigations, as the most widely used materials in car brakes. Samples for surface analysis were prepared from disc operating in stand and road conditions. Stand tests were pin-on-disc kind. Operating parameters for the stand tests were chosen on the basis of results of our earlier research. Topography of brake disc surface was evaluated by surface roughness measurements. The surface layer was examined with use of metallography and scanning electron microscopy. In order to differentiate structures of grey cast iron brake discs SE and BSE modes were used in scanning electron microscopy. Chemical investigations of samples were done by X-ray analysis linked with SEM. Studies showed influence of grey cast iron structures on tribological processes taking place in a brake friction pair. The surface layer of grey cast iron discs was described and features and functions of separated structures were presented. On the basis of the obtained results a physical model of friction mechanism was created. Special attention was paid to the influence of graphite on the run of tribological processes and mechanism of compaction and removal of wear debris.

  13. The trochanteric fat pad

    Directory of Open Access Journals (Sweden)

    P. Panettiere

    2011-05-01

    Full Text Available Technological developments based on the use of autologous white adipose tissue (WAT attracted attention to minor fat depots as possible sources of adipose tissue. In plastic surgery, the trochanteric fatty pad is one of the most used WAT depots for its location and organoleptic characteristics that make it particularly suitable for reconstructive procedures. Despite its wide use in clinic, the structure of this depot has never been studied in detail and it is not known if structural differences exist among trochanteric fat and other subcutaneous WAT depots. The present study was performed on trochanteric fat pad with the aim to clarify the morphology of its adipocytes, stroma and microcirculation, with particular reference to the stem niches. Histological and ultrastructural studies showed that the main peculiar feature of the trochanteric fat concerns its stromal component, which appears less dense than in the other subcutaneous WATs studied. The intra-parenchymal collagen stroma is poor and the extracellular compartment shows large spaces, filled with electron-light material, in which isolated collagen bundles are present. The adipocytes are wrapped in weak and easily detachable collagen baskets. These connective sheaths are very thin compared to the sheaths in other subcutaneous WAT depots. The capillaries are covered by large, long and thin elements surrounded by an external lamina; these perivascular cells are poor in organelles and mainly contain poly-ribosomes. In conclusion, when compared to other WAT deposits, the trochanteric fatty pad shows structural peculiarities in its stroma and microcirculation suggesting a high regenerative potential. Resistance, dissociability, microvascular weft and high regenerative potential make the trochanteric fatty pad a privileged source for harvesting in autologous WAT-based regenerative procedures.

  14. MuPAD tutorial

    CERN Document Server

    Creutzig, Christopher

    2004-01-01

    This book explains the basic use of the software package called MuPAD and gives an insight into the power of the system. MuPAD is a so-called com­ puter algebra system, which is developed mainly by Sciface Software and the MuPAD Research Group of the University of Paderborn in Germany. This introduction addresses mathematicians, engineers, computer scientists, natural scientists and, more generally, all those in need of mathematical com­ putations for their education or their profession. Generally speaking, this book addresses anybody who wants to use the power of a modern computer algebra package. There are two ways to use a computer algebra system. On the one hand, you may use the mathematical knowledge it incorporates by calling system functions interactively. For example, you can compute symbolic integrals or generate and invert matrices by calling appropriate functions. They comprise the system's mathematical intelligence and may implement sophisticated al­ gorithms. Chapters 2 through 15 discuss this...

  15. The Role of Solid Lubricants for Brake Friction Materials

    Directory of Open Access Journals (Sweden)

    Werner Österle

    2016-02-01

    Full Text Available This review article comprises of three parts. Firstly, reports of brake manufacturers on the beneficial impact of solid lubricants for pad formulations are surveyed. Secondly, since tribofilms were identified to play a crucial role in friction stabilization and wear reduction, the knowledge about tribofilm structures formed during automotive braking was reviewed comprehensively. Finally, a model for simulating the sliding behavior of tribofilms is suggested and a review on modelling efforts with different model structures related to real tribofilms will be presented. Although the variety of friction composites involved in commercial brake systems is very broad, striking similarities were observed in respect to tribofilm nanostructures. Thus, a generalization of the tribofilm nanostructure is suggested and prerequisites for smooth sliding performance and minimal wear rates have been identified. A minimum of 13 vol % of soft inclusions embedded in an iron oxide based tribofilm is crucial for obtaining the desired properties. As long as the solid lubricants or their reaction products are softer than magnetite, the main constituent of the tribofilm, the model predicts smooth sliding and minimum wear.

  16. The Electronic Wedge Brake - EWB

    Energy Technology Data Exchange (ETDEWEB)

    Ho, L.M.; Roberts, R.P.; Hartmann, H.; Gombert, B. [Siemens VDO Automotive (Germany)

    2006-07-01

    Future driver assistance systems will not only monitor the current traffic situation, but actively assist the driver in the day to day driving routines and as well in emergency situations. Autonomous intervention in the vehicle behavior will help to keep the vehicle under control, even in hazardous situations. A fast and smart braking system is one of the basics for the next generation of driver assistance systems. Siemens VDO sees its electronic wedge brake (EWB) brake-by-wire technology as the answer to future vehicle chassis safety, weight, reliability and space requirements. Particularly in the automobile sector, there is an increasing trend towards replacing existing hydraulic or pneumatic brake systems with drive 'by-wire' solutions. While mechatronics, i.e. intelligent, controllable electromechanical actuators, are already in use in many automotive and non automotive areas, there are particularly strict requirements for purely electromechanical braking systems which require complex development processes. These are highly safety critical systems, which must provide both excellent control quality and sophisticated fail-safe behavior. The challenge is to achieve a high power density in the wheel brake actuators. (orig.)

  17. On airborne nano/micro-sized wear particles released from low-metallic automotive brakes.

    Science.gov (United States)

    Kukutschová, Jana; Moravec, Pavel; Tomášek, Vladimír; Matějka, Vlastimil; Smolík, Jiří; Schwarz, Jaroslav; Seidlerová, Jana; Safářová, Klára; Filip, Peter

    2011-04-01

    The paper addresses the wear particles released from commercially available "low-metallic" automotive brake pads subjected to brake dynamometer tests. Particle size distribution was measured in situ and the generated particles were collected. The collected fractions and the original bulk material were analyzed using several chemical and microscopic techniques. The experiments demonstrated that airborne wear particles with sizes between 10 nm and 20 μm were released into the air. The numbers of nanoparticles (release of nanoparticles was measured when the average temperature of the rotor reached 300°C, the combustion initiation temperature of organics present in brakes. In contrast to particle size distribution data, the microscopic analysis revealed the presence of nanoparticles, mostly in the form of agglomerates, in all captured fractions. The majority of elements present in the bulk material were also detected in the ultra-fine fraction of the wear particles.

  18. Thermomechanical Simulation of Wear and Hot Bands in a Disc Brake by Adopting an Eulerian Approach

    OpenAIRE

    Rashid, Asim; Strömberg, Niclas

    2013-01-01

    In this paper frictional heating of a disc brake is simulated while taking wear into account. By performing thermomechanical finite element analysis, it is studied how the wear history will influence the development of hot bands. The frictional heat analysis is based on an Eulerian formulation of the disc, which requires significantly lower computational time as compared to a standard Lagrangian approach. A real disc-pad system to a heavy truck is considered, where complete three-dimensional ...

  19. Brake Performance Analysis of ABS for Eddy Current and Electrohydraulic Hybrid Brake System

    Directory of Open Access Journals (Sweden)

    Ren He

    2013-01-01

    Full Text Available This paper introduces an eddy current and electro-hydraulic hybrid brake system to solve problems such as wear, thermal failure, and slow response of traditional vehicle brake system. Mathematical model was built to calculate the torque of the eddy current brake system and hydraulic brake system and analyze the braking force distribution between two types of brake systems. A fuzzy controller on personal computer based on LabVIEW and Matlab was designed and a set of hardware in the loop system was constructed to validate and analyze the performance of the hybrid brake system. Through lots of experiments on dry and wet asphalt roads, the hybrid brake system achieves perfect performance on the experimental bench, the hybrid system reduces abrasion and temperature of the brake disk, response speed is enhanced obviously, fuzzy controller keeps high utilization coefficient due to the optimal slip ratio regulation, and the total brake time has a smaller decrease than traditional hydraulic brake system.

  20. Pad

    Institute of Scientific and Technical Information of China (English)

    舟华

    2011-01-01

    Pad又叫平板电脑,这种由苹果iPad在2010年掀起热潮的移动终端.在本年度终于全面爆发。在刚结束的CES 2011上,各大厂商纷纷发力,推出搭载各种操作系统的Pad新品:摩托罗拉Xoom、黑莓PlayBook、联想乐Pad……加上即将来临的苹果iPad2,2011无疑就是Pad年。

  1. Edgeless silicon pad detectors

    Science.gov (United States)

    Perea Solano, B.; Abreu, M. C.; Avati, V.; Boccali, T.; Boccone, V.; Bozzo, M.; Capra, R.; Casagrande, L.; Chen, W.; Eggert, K.; Heijne, E.; Klauke, S.; Li, Z.; Mäki, T.; Mirabito, L.; Morelli, A.; Niinikoski, T. O.; Oljemark, F.; Palmieri, V. G.; Rato Mendes, P.; Rodrigues, S.; Siegrist, P.; Silvestris, L.; Sousa, P.; Tapprogge, S.; Trocmé, B.

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in "edgeless" planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5±8 stat..±6 syst.) μm.

  2. Edgeless silicon pad detectors

    Energy Technology Data Exchange (ETDEWEB)

    Perea Solano, B. [CERN, CH-1211 Geneva 23 (Switzerland)]. E-mail: blanca.perea.solano@cern.ch; Abreu, M.C. [LIP and University of Algarve, 8000 Faro (Portugal); Avati, V. [CERN, CH-1211 Geneva 23 (Switzerland); Boccali, T. [INFN Sez. di Pisa and Scuola Normale Superiore, Pisa (Italy); Boccone, V. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Bozzo, M. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Capra, R. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Casagrande, L. [INFN Sez. di Roma 2 and Universita di Roma 2, Rome (Italy); Chen, W. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Eggert, K. [CERN, CH-1211 Geneva 23 (Switzerland); Heijne, E. [CERN, CH-1211 Geneva 23 (Switzerland); Klauke, S. [CERN, CH-1211 Geneva 23 (Switzerland); Li, Z. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Maeki, T. [Helsinki Institute of Physics, Helsinki (Finland); Mirabito, L. [CERN, CH-1211 Geneva 23 (Switzerland); Morelli, A. [INFN Sez. di Genova and Universita di Genova, Genoa (Italy); Niinikoski, T.O. [CERN, CH-1211 Geneva 23 (Switzerland); Oljemark, F. [Helsinki Institute of Physics, Helsinki (Finland); Palmieri, V.G. [Helsinki Institute of Physics, Helsinki (Finland); Rato Mendes, P. [LIP and University of Algarve, 8000 Faro (Portugal); Rodrigues, S. [LIP and University of Algarve, 8000 Faro (Portugal); Siegrist, P. [CERN, CH-1211 Geneva 23 (Switzerland); Silvestris, L. [INFN Sez. Di Bari, Bari (Italy); Sousa, P. [LIP and University of Algarve, 8000 Faro (Portugal); Tapprogge, S. [Helsinki Institute of Physics, Helsinki (Finland); Trocme, B. [Institut de Physique Nucleaire, Villeurbanne (France)

    2006-05-01

    We report measurements in a high-energy pion beam of the sensitivity of the edge region in 'edgeless' planar silicon pad diode detectors diced through their contact implants. A large surface current on such an edge prevents the normal reverse biasing of the device, but the current can be sufficiently reduced by the use of a suitable cutting method, followed by edge treatment, and by operating the detector at low temperature. The depth of the dead layer at the diced edge is measured to be (12.5{+-}8{sub stat.}.{+-}6{sub syst.}) {mu}m.

  3. iPad Made Simple

    CERN Document Server

    Trautschold, Martin; Learning, MSL Made Simple

    2010-01-01

    The new iPad is sleek, powerful, and most importantly, it's much more than just a big iPhone. Your iPad is can be used for reading, surfing the web, emailing, watching TV/Movies, getting work done, and much more. And with the upcoming wave of iPad apps, the possibilities are endless. iPad X Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instructions on how to set up and use the iPad * Illust

  4. Magnetic Braking Revisited

    CERN Document Server

    Taam, R E

    2003-01-01

    We present a description for the angular momentum loss rate due to magnetic braking for late type stars taking into account recent observational data on the relationship between stellar activity and rotation. The analysis is based on an idealized two component coronal model subject to constraints imposed on the variation of the coronal gas density with rotation period inferred from the observed variation of X-ray luminosity, L_x, with rotation rate, Omega, (L_x \\propto Omega^2) for single rotating dwarfs. An application of the model to high rotation rates leads to a gradual turnover of the X-ray luminosity which is similar to the saturation recently observed in rapidly rotating dwarfs. The resulting angular momentum loss rate, \\dot J, depends on Omega in the form \\dot J \\propto Omega^beta where beta ~ 3 for slow rotators and ~ 1.3 for fast rotators. The relation at high rotation rates significantly differs from the power law exponent for slowly rotating stars, depressing the angular momentum loss rate without...

  5. Finite Element Analysis on the Brake Noise of Disc Brake Based on NASTRAN%基于Nastran盘式制动器制动噪声的有限元分析

    Institute of Scientific and Technical Information of China (English)

    方韶华; 方永寿

    2015-01-01

    为降低盘式制动器制动尖叫噪声,应用制动盘和摩擦片的耦合模型直接复特征值分析方法研究制动器的运动状态,采用Nastran有限元软件建立制动盘和摩擦片的有限元模型,用线性弹簧力来表示制动摩擦面间的法向力,其中线性弹簧力与摩擦因数的乘积就是制动摩擦力;通过解特征方程得到特征根,并根据特征根实部的正负判断制动器发生制动尖叫噪声的趋势。结果显示,盘片间的摩擦不规则是制动器噪声产生重要因素,认为制动器噪声可以通过降低制动器盘片间的摩擦因数来抑制。%In order to suppress the brake noise of disc brake, motion stability of disc brake is studied using a direct complex eigenvalue analysis technique of coupled model of the disc and the pads. Finite element software NASTRAN is applied to establish finite element model of disc brake including one disc and two pads.In the model, the normal force at the contact interface is shown with linear spring force. The friction force is taken as the product of linear spring force and friction coefficient. Numerical simulation result shows that the friction coefficient of the disc and the pads have significant influence on the occurrence of brake noise. Brake noise can be suppressed by reducing the friction coefficient.

  6. The design of brake fatigue testing system

    Directory of Open Access Journals (Sweden)

    Huang, Xiaoya

    2015-01-01

    Full Text Available Brake is used to reduce the operating speed of the machinery equipment or to make it stop. It is essential for vehicles, climbing machines and many fixed equipment in their safety work. Brake tester is an experimental apparatus to measure and analyse the braking performance. Based on the PLC technology and for the purpose of testing brake shoe friction material’s life, this paper designed a virtual brake test platform. In it, inverter were used to control the motor, so that it can load automatically and ensure brake drum constant speed output; what is more, closed loop control system were used to control the brake shoe, so that the cylinder pressure keeps stable in the process of dynamic braking.

  7. Brakes, brake control and driver assistance systems function, regulation and components

    CERN Document Server

    2014-01-01

    Braking systems have been continuously developed and improved throughout the last years. Major milestones were the introduction of antilock braking system (ABS) and electronic stability program. This reference book provides a detailed description of braking components and how they interact in electronic braking systems. Contents Motor vehicle safety.- Basic principles of vehicle dynamics.- Car braking systems.- Car braking-system components.- Wheel brakes.- Antilock breaking systems.- Traction control system.- Electronic stability program.- Automatic brake functions.- Hydraulic modulator.- Sensors for brake control.- Sensotronic brake control.- Active steering.- Occupant protection systems.- Driver assistance systems.- Adaptive cruise control.- Parking systems.- Instrumentation.- Orientation methods.- Navigation systems.- Workshop technology. The target groups Motor-vehicle technicians in education and vocational training Master-mechanics and technicians in garage-workshops Teachers and lecturers in vocation...

  8. Braking Distance Prediction by Hydroplaning Analysis of 3-D Patterned Tire Model

    Science.gov (United States)

    Cho, Jin-Rae; Choi, Joo-Hyoung; Lee, Hong-Woo; Woo, Jong-Shik; Yoo, Wan-Suk

    In this paper, we present a wet-road braking distance estimate for the vehicles equipped with ABS (Anti-lock Brake System). In order to effectively compute the interval-wise braking times and the resulting total braking distance, we divide the entire speed interval at braking into finite number of uniform sub-intervals and apply the energy conservation law to individual sub-intervals. The proposed method is based on a numerical-analytical approach such that the frictional energy loss of the patterned tire is computed by 3-D hydroplaning analysis while the other at the disc pad is analytically derived. The hydroplaning simulation is performed by generally coupling an Eulerian finite volume method and an explicit Lagrangian finite element method. The operation of ABS is numerically implemented by controlling the tire angular velocity such that the preset tire slip ratio on the wet road is maintained. Numerical results are presented to illustrative and verify the the proposed numerical estimate.

  9. Magnetic braking in ultracompact binaries

    CERN Document Server

    Farmer, Alison

    2010-01-01

    Angular momentum loss in ultracompact binaries, such as the AM Canum Venaticorum stars, is usually assumed to be due entirely to gravitational radiation. Motivated by the outflows observed in ultracompact binaries, we investigate whether magnetically coupled winds could in fact lead to substantial additional angular momentum losses. We remark that the scaling relations often invoked for the relative importance of gravitational and magnetic braking do not apply, and instead use simple non-empirical expressions for the braking rates. In order to remove significant angular momentum, the wind must be tied to field lines anchored in one of the binary's component stars; uncertainties remain as to the driving mechanism for such a wind. In the case of white dwarf accretors, we find that magnetic braking can potentially remove angular momentum on comparable or even shorter timescales than gravitational waves over a large range in orbital period. We present such a solution for the 17-minute binary AM CVn itself which a...

  10. 30 CFR 56.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... stop under normal operating conditions. Parking or emergency (secondary) brakes are not to be actuated... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Brakes. 56.14101 Section 56.14101...

  11. 49 CFR 236.712 - Brake pipe.

    Science.gov (United States)

    2010-10-01

    ...-pneumatic brake equipment on each vehicle of the train. ... 49 Transportation 4 2010-10-01 2010-10-01 false Brake pipe. 236.712 Section 236.712 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.712 Brake pipe. A...

  12. iPads og undervisningsdifferentiering

    DEFF Research Database (Denmark)

    Lorentzen, Rasmus Fink

    2013-01-01

    Artiklen er blevet til på baggrund af udviklingsprojektet med iPad i Odder Kommune. Den generaliserer på baggrund af en række eksempler herfra og peger på at med iPad'en drejer det sig om at udnytte mulighederne for at lade eleverne arbejde producerende, kollaborativt og fagligt meningsfuldt...

  13. Mountain Braking Test Venue Study

    Science.gov (United States)

    2013-12-12

    resistance, and engine braking. The following equation shows this relationship: PB = W ∙ V ∙ ϴ - PA – PRR – PE. (1) The engine braking power...vehicle rolling resistance is due to tires and can be characterized as: PRR = CRR ∙ W ∙ V ∙ CT / 375 (HP), (3) where CRR is the tire-road interface...resistance is proportional to tire load results in the following equation: PRR = (0.0002455 ∙ V2 + 1.784 ∙ V) ∙ W/80,000 (HP). (4) The power absorbed

  14. Braking performance of aircraft tires

    Science.gov (United States)

    Agrawal, Satish K.

    This paper brings under one cover the subject of aircraft braking performance and a variety of related phenomena that lead to aircraft hydroplaning, overruns, and loss of directional control. Complex processes involving tire deformation, tire slipping, and fluid pressures in the tire-runway contact area develop the friction forces for retarding the aircraft; this paper describes the physics of these processes. The paper reviews the past and present research efforts and concludes that the most effective way to combat the hazards associated with aircraft landings and takeoffs on contaminated runways is by measuring and displaying in realtime the braking performance parameters in the aircraft cockpit.

  15. iPad Portable Genius

    CERN Document Server

    McFedries, Paul

    2010-01-01

    Everything everyone wants to know about using the Apple iPad. On January 27, 2010, Apple announced the latest in its line of revolutionary, ultraportable devices - the iPad. iPad Portable Genius is the latest in a line of ultra handy, go-to and goes-with you anywhere guides for getting the most out of a new Apple product. Written to provide readers with highly useful information that's easily accessible, iPad Portable Genius is full of tips, tricks and techniques for maximizing each of the iPad's most popular features.:; Designed in full-color with an Apple look and feel, and written in a hip,

  16. The design of brake fatigue testing system

    OpenAIRE

    2015-01-01

    Brake is used to reduce the operating speed of the machinery equipment or to make it stop. It is essential for vehicles, climbing machines and many fixed equipment in their safety work. Brake tester is an experimental apparatus to measure and analyse the braking performance. Based on the PLC technology and for the purpose of testing brake shoe friction material’s life, this paper designed a virtual brake test platform. In it, inverter were used to control the motor, so that it can load automa...

  17. Developing of a software for determining advanced brake failures in brakes test bench

    Directory of Open Access Journals (Sweden)

    Hakan Köylü

    2016-08-01

    Full Text Available At present time, the brake test bench conducts the braking and suspension tests of front or rear axles and the test results are evaluated through one axle. The purpose of the brake testing system is to determine braking force and damping coefficient dissymmetry of one axle. Thus, this test system evaluates the performance of service brake, hand brake and suspension systems by considering separately front and rear axle dissymmetry. For this reason, the effects of different braking and damping forces applied by right and left wheels of both axles on braking performance of all vehicle are not determined due to available algorithm of the test bench. Also, the other brake failures are not occurred due to the algorithm of brake test system. In this study, the interface has been developed to determine the other effects of dissymmetry and the other brake failures by using the one axle results of brake test bench. The interface has algorithm computing the parameters according to the interaction between front and rear axles by only using measured test results. Also, it gives the warnings by comparing changes in the parameters with braking performance rules. Braking and suspension tests of three different vehicles have been conducted by using brake test bench to determine the performance of the algorithm. Parameters based on the axle interaction have been calculated by transferring brake test results to the interface and the test results have been evaluated. As a result, the effects of brake and suspension failures on braking performance of both axle and vehicle have been determined thanks to the developed interface.

  18. IDEAL BRAKE FORCE DISTRIBUTION BETWEEN THE AXLES OF THE TWO-AXLE VEHICLE SERVICE BRAKE APPLICATIONS

    Directory of Open Access Journals (Sweden)

    M. Podryhalo

    2015-07-01

    Full Text Available The obtained analytical expressions allow us to evaluate the stability of two-axle vehicles at various slowdowns. An analytical expression for calculating the ideal according to condition stability ensuring of a two-axle vehicle at service brake applications of brake force distribution allows to offer automatic control devices for brake force adjucement. With decellerationg growth of the two-axle vehicle at service braking the braking force acting on the front axle should decrease relative to the brake force on the rear axle.

  19. iPad Fully Loaded

    CERN Document Server

    Hess, Alan

    2011-01-01

    Alan knows-and he's telling! All about your iPad. It's an iPod. It's an e-reader. It's an instant classic. And now you can discover all the secrets to this dazzling device, thanks to Alan Hess. You may think you already know your iPad inside and out, until Alan shows you how to write your own books, stream your iTunes, view comic book files, and transfer photos with Eye-Fi. He provides all the tips and techniques you need to get the absolute most out of your iPad. Figure you already get all things iPad? Don't count on it-until you read this book! Browse through the iBooksStore and start speed

  20. Teaching with iPads

    Science.gov (United States)

    Maj, Hubert

    2015-04-01

    Bilingual students in high school with bilingual units in Boguchwała have received iPads for learning English and a few subjects using CLIL (biology, basics of entrepreneurship, geography, IT and mathematics). Lessons with iPads are interesting for students for several reasons. First of all, teenagers like new technologies and using iPads for teaching helps students to learn by fun. Secondly, iPads give new possibilities of looking for knowledge about each theme. Moreover, teaching with iPads develops students' engagement. They have a chance to choose a few among over 65 000 applications for gathering and then presenting information about the lesson topic. They can easily prepare presentations, movies, cartoons, mind maps or whatever they like. Teaching students, thanks to the iPads, makes it their initiative, and the teacher can inspire them to look for the knowledge rather than disciplining pupils. But teaching with iPads is connected with many problems. For instance, there are not any examples on how to teach using these tools. It is very up-to-date technology and teachers firstly must learn the possibilities of iPads and look for new applications. It takes much time, especially at the beginning, and is difficult especially for inexperienced teachers. In addition, it is almost impossible to maintain control of the iPads for all of the students during the lesson. They can use their iPads for something unconnected with the topic of the lesson. Thirdly is lack of time - active methods (with iPads as well) are more time-consuming and it could be that they do not finish the whole program. And of course the last, but not at least, is the problem of money. Some of the applications must be paid for, and it is usually obligatory to possess a credit card. Fortunately, it is not expensive - applications usually cost a few euros and many of them are free and really good.

  1. Brake Fluid Compatibility Studies with Advanced Brake Systems

    Science.gov (United States)

    2016-01-16

    identified as silane based compounds. Therefore, we can eliminate brake fluid polymerization as a possible cause since no siloxane based polymers were...cm-1 indicate presence of O-H peak corresponding UNCLASSIFIED DRAFT UNCLASSIFIED 21 to water ; 1631.50 cm-1 indicate presence of C=C peak...measurements are usually made using an auxiliary liquid with a known density. In this case, water is used as the auxiliary liquid. The weight of the o

  2. A double modal synthesis approach for brake squeal prediction

    Science.gov (United States)

    Monteil, M.; Besset, S.; Sinou, J.-J.

    2016-03-01

    This paper is devoted to propose a new efficient reduction method for predicting the stability analysis of a brake system subjected to friction-induced vibration. The finite element brake system under study is composed of a disc and a pad. The contact is modeled by introducing contact elements at the friction interface with the classical Coulomb law and a constant friction coefficient. It will be demonstrated that it is possible to build efficient reduced finite element models by developing a reduced model based on a Double Modal Synthesis (i.e. a classical modal reduction via Craig & Bampton plus a condensation at the frictional interface). Special attention is being conducted to validate the convergence of the reduced model especially on the approximation of the unstable modes with respect to real and imaginary parts. This complete numerical strategy based on Double Modal Synthesis allows us to perform relevance squeal prediction of unstable vibration modes. It is demonstrated that the numerical results via the Double Modal Synthesis are in good agreement with those of the classical Craig & Bampton method.

  3. 49 CFR 393.49 - Control valves for brakes.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Control valves for brakes. 393.49 Section 393.49... NECESSARY FOR SAFE OPERATION Brakes § 393.49 Control valves for brakes. (a) General rule. Except as provided..., which is equipped with power brakes, must have the braking system so arranged that one application...

  4. 49 CFR 393.41 - Parking brake system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Parking brake system. 393.41 Section 393.41... NECESSARY FOR SAFE OPERATION Brakes § 393.41 Parking brake system. (a) Hydraulic-braked vehicles...,536 kg (10,000 pounds) shall be equipped with a parking brake system as required by FMVSS No....

  5. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  6. Design and Analysis of a Novel Centrifugal Braking Device for a Mechanical Antilock Braking System.

    Science.gov (United States)

    Yang, Cheng-Ping; Yang, Ming-Shien; Liu, Tyng

    2015-06-01

    A new concept for a mechanical antilock braking system (ABS) with a centrifugal braking device (CBD), termed a centrifugal ABS (C-ABS), is presented and developed in this paper. This new CBD functions as a brake in which the output braking torque adjusts itself depending on the speed of the output rotation. First, the structure and mechanical models of the entire braking system are introduced and established. Second, a numerical computer program for simulating the operation of the system is developed. The characteristics of the system can be easily identified and can be designed with better performance by using this program to studying the effects of different design parameters. Finally, the difference in the braking performance between the C-ABS and the braking system with or without a traditional ABS is discussed. The simulation results indicate that the C-ABS can prevent the wheel from locking even if excessive operating force is provided while still maintaining acceptable braking performance.

  7. Friction Wear Property of Brake Materials by Copper-based Powder Metallurgy With Various Brake Speeds

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xiu; GAO Hong-xia; WEI Xiu-lan

    2004-01-01

    The experiment is conducted on MM-1000 friction test machine, which tests friction wear property of copper-based brake materials by powder metallurgy at different brake speeds. It shows that the coefficient of friction and wear volume are greatly influenced by brake speed. When the brake speed is 4000 r/min, which is a bit higher, the material still has a higher coefficient of friction with 0.47. When the brake speed is over 4000r/min, the coefficient of friction decreased rapidly. When the brake speed is 3000r/min, the material's wear is in its minimum. That is to say no matter how higher or lower the brake speed is the wear volume is bigger relatively. With the brake speed of the lower one it mainly refers to fatigue wear; while of higher one it mainly refers to abradant and oxidation wear.

  8. CFD Analysis Of Straight Ventilated Disc Brake

    Directory of Open Access Journals (Sweden)

    Nikhil K

    2016-05-01

    Full Text Available Brakes are the key pieces of a vehicle that plays an active role in safety and performance of the system. The study of aerodynamic cooling of a disc brake in real working condition of vehicle is important in present situations. Brake discs get very hot quickly, so it should be dissipated properly through different modes of heat transfer. Contributions of these heat transfer modes are different in different type of problems. The cooling transfer rates are different in vane surface and frictional surface of a disc brake. Also the temperature varies in each small interval of braking time. So a transient problem simulation is important to study the cooling of a disc brake when a vehicle decelerates from a particular speed. ANSYS CFX tool is used for the simulation of this transient problem.

  9. An Experimental Analysis of Brake Efficiency Using four Fluids in a Disc Brake System

    Directory of Open Access Journals (Sweden)

    Seth Daniel Oduro

    2013-02-01

    Full Text Available The paper studies disc brake failure in Mini-buses using an experimental analysis to test the maximum braking force when different brake fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The experimental results clearly showed that the soap solution appears to be the best fluid as far as low viscosity and stability of viscosity with increase in temperature are concerned. However, the soap solution is not compatible with other fluid which makes it difficult to be substitute as a clean brake fluid. The result of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal brake of 117 kN produce a brake force of 0.96 kN for clean brake fluid, 0.91 kN for the less dirty, 0.85 kN for dirty and 1.44 kN for soap solution. The value of 1.44 kN which was achieved when the soap solution was used indicated a positive braking force and the indicating that soap solution could be used to produce a high pedal force within a very short time (about 10-30 min and can therefore be used only in case of emergency. The brake efficiency test indicated that under hot conditions the braking efficiency is reduced and the presence of air in the system renders the braking ineffective because higher pedal force was needed to be able to produce a significant braking force which is noted for causing brake failure.

  10. Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

    Science.gov (United States)

    2008-05-20

    shields removed, inspect the internal brake components, perform a camshaft rotation test and record the measurement obtained. c. If with non-removable...preceding 24 months, perform a camshaft rotation test and record the measurement. (2) When proof of wheel removal is not provided, remove brake drum(s...adjustment. Reject the vehicle if: • The adjustment is not within the manufacturer’s specifications. 15. Brake Camshafts Procedure: With

  11. Automotive brake squeal analysis with rotating finite elements of asymmetric disc in time

    Science.gov (United States)

    Kang, Jaeyoung

    2017-04-01

    The new finite element brake squeal model is proposed where the finite elements of a real brake disc rotate in time. Contact nodal forces between the rotating disc and stationary pads are allocated to the moving contact area at every time step. When the proposed model is applied to an asymmetric automotive brake disc, it becomes the periodic time-varying brake system. The stability boundary of the discrete time-varying system is numerically calculated by the Floquet theory. Also, the quasi-static linearized eigenvalue analysis is conducted to show that the unstable modes repeatedly appear at the short interval of the disc rotation angle. The results are consistent with the angle-dependent local phenomenon of squeal termed squeal periodicity in the squeal experiment. In the nonlinear time-domain analysis, the squeal vibration increases and then decays in time for the rotating mode shape functions. It demonstrates that the rotation of an asymmetric disc can change the nonlinear squeal behavior as well as the linear stability character drastically.

  12. Design and preliminary validation of a tool for the simulation of train braking performance

    Institute of Scientific and Technical Information of China (English)

    Luca Pugi; Monica Malvezzi; Susanna Papini; Gregorio Vettori

    2013-01-01

    Train braking performance is important for the safety and reliability of railway systems. The availability of a tool that allows evaluating such performance on the basis of the main train features can be useful for train system designers to choose proper dimensions for and optimize train’s subsystems. This paper presents a modular tool for the prediction of train braking performance, with a par-ticular attention to the accurate prediction of stopping distances. The tool takes into account different loading and operating conditions, in order to verify the safety require-ments prescribed by European technical specifications for interoperability of high-speed trains and the corresponding EN regulations. The numerical results given by the tool were verified and validated by comparison with experi-mental data, considering as benchmark case an Ansaldo EMU V250 train-a European high-speed train-currently developed for Belgium and Netherlands high-speed lines, on which technical information and experimental data directly recorded during the preliminary tests were avail-able. An accurate identification of the influence of the braking pad friction factor on braking performances allowed obtaining reliable results.

  13. Dynamics of Braking Vehicles: From Coulomb Friction to Anti-Lock Braking Systems

    Science.gov (United States)

    Tavares, J. M.

    2009-01-01

    The dynamics of braking of wheeled vehicles is studied using the Coulomb approximation for the friction between road and wheels. The dependence of the stopping distance on the mass of the vehicle, on the number of its wheels and on the intensity of the braking torque is established. It is shown that there are two regimes of braking, with and…

  14. BRAKE TEST OF SiCp/A356 BRAKE DISK AND INTERPRETATION OF EXPERIMENTAL RESULTS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhiyong; HAN Jianmin; LI Weijing; WANG Jinhua

    2007-01-01

    Material properties are obvious different between aluminum matrix composites and iron and steel materials. After the brake disk braked at the same speed, the average temperature of the aluminum brake disk is 1.5 times as high as one of iron and steel brake disk, the thermal expansion value of the aluminum brake disk is 2 times as big as one of iron and steel brake disk. Mechanical property of the material decreases with the temperature increasing generally during braking, on the other hand, the big thermal stress in the brake disk happens because the material expansion is constrained. Firstly, the reasons of the thermal stress generation and the fracture failure of brake disks during braking are analyzed qualitatively by virtue of three-bar stress frame and sandwich deformation principles in physic, and then the five constraints which cause the thermal stress are summarized. On the base of the experimental results on the 1:1 emergency brake test, the thermal stress and temperature fields are simulated; The behavior of the fracture failure is interpreted semi-quantitatively by finite element analysis. There is the coincident forecast for the fraction position in term of the two methods. In the end, in the light of the analysis and calculation results, it is the general principles observed by the structure design and assembly of the brake disk that are summarized.

  15. Verification of pneumatic railway brake models

    Science.gov (United States)

    Piechowiak, Tadeusz

    2010-03-01

    The article presents a survey of diverse methods for validation of pneumatic train brake modelling. Various experimental measurements of railway pneumatic brakes were made chiefly on a test stand at Poznań University of Technology; other test stands and some results have been taken from the literature. The measurements, some of them unconventional, were performed on separate pneumatic elements, brake devices, the brake pipe and fragments thereof. Mechanical devices were also included. The experimental measurement results were used for the verification of numerical models and for the determination of parameters. The latter was partially performed using an optimisation method.

  16. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

    Yang Yan; Lin Chang-Hua; Li Hui; Zhou Jing

    2004-01-01

    A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield.

  17. Video game induced knuckle pad.

    Science.gov (United States)

    Rushing, Mary E; Sheehan, Daniel J; Davis, Loretta S

    2006-01-01

    Controversy and concern surround the video game playing fascination of children. Scientific reports have explored the negative effects of video games on youth, with a growing number recognizing the actual physical implications of this activity. We offer another reason to discourage children's focus on video games: knuckle pads. A 13-year-old black boy presented with an asymptomatic, slightly hyperpigmented plaque over his right second distal interphalangeal joint. A punch biopsy specimen confirmed knuckle pad as the diagnosis, and a traumatic etiology from video game playing was suspected. Knuckle pads can be painful, cosmetically unappealing, and refractory to treatment. They can now be recognized as yet another potential adverse consequence of chronic video game playing.

  18. Analysis of Braking Characteristic for Tire Rotary-drum Machine%轮胎转鼓试验设备制动特性分析

    Institute of Scientific and Technical Information of China (English)

    鲍晓东; 侯勇; 张绍国

    2012-01-01

    制动系统是转鼓试验设备重要的安全部件,通过分析制动系统的材料属性,建立了制动系统的简化模型.对盘式制动器在不同制动压力下的紧急制动过程进行仿真模拟,深入分析了制动系统在不同工作负荷下制动装置摩擦表面的应力、温度场分布情况以及有效的制动时间.对比不同工况下的计算结果,得到了制动盘和刹车片的应力和温度场分布规律,并且分析了制动压力与制动时间之间的关系.结果表明制动压力越大,制动时间越短,但制动系统温升越明显,相关结论为指导设备制动系统参数的合理选定提供了理论依据.%Braking system is an important safety component for the rotating, drum test equipment, through the analysis on the material properties of the braking system, the model of braking system was es-tablishea\\Emergency braking process of the disc brake was simulated under different pressure,and then friction surface stress, temperature field distribution and effective braking time of brake system in different workload stress were further analyzedAccording to the calculation results ,stress and temperature field distribution for braking disc and pad were obtained,and relationship between braking pressure and braking time was analyzed.The results show that as the braking pressure enhanced, the braking time is shorter,however, the temperature rise for braking system is more obvious.Conclusion provides a theoretical basis for brake system rational parameter selection.

  19. Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, D.M., E-mail: davidb@itox.ch [Consultant in Toxicology, Geneva (Switzerland); Rogers, R.A., E-mail: rarogers5@yahoo.com [Rogers Imaging, Needham, MA (United States); Sepulveda, R. [Rogers Imaging, Needham, MA (United States); Kunzendorf, P., E-mail: Peter.Kunzendorf@GSA-Ratingen.de [GSA Gesellschaft für Schadstoffanalytik mbH, Ratingen (Germany); Bellmann, B. [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Ernst, H., E-mail: Heinrich.ernst@item.fraunhofer.de [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Creutzenberg, O. [Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover (Germany); Phillips, J.I., E-mail: jim.phillips@nioh.nhls.ac.za [National Institute for Occupational Health, National Health Laboratory Service, Johannesburg South Africa and Department of Biomedical Technology, Faculty of Health Sciences, University of Johannesburg, Johannesburg (South Africa)

    2015-02-15

    This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly

  20. Diagnosis of heel pad injuries

    DEFF Research Database (Denmark)

    Matteoli, Sara

    of the present thesis is to obtain a thorough understanding of the mechanical properties of in vivo human heel pad by studying the anatomical and physiological structure of healthy and diseased tissue, and to develop quantitative methods for diagnosing injuries. A compression device was built in order to record...... load-displacement curves from in vivo heel pads. To ensure applicability also for pathological feet, the device uses force levels lower than those needed to reproduce the physiological conditions of walking. One hundred twenty seven healthy volunteers were enrolled for compression tests and ultrasound...

  1. Effect of surface texture and working gap on the braking performance of the magnetorheological fluid brake

    Science.gov (United States)

    Wang, Na; Li, Dong Heng; Li Song, Wan; Chao Xiu, Shi; Zhi Meng, Xiang

    2016-10-01

    In this paper, the effect of the surface textures of braking disc on the braking performance is experimentally investigated under the conditions of different working gaps and applied currents. For this purpose, a new configuration of magnetorheological fluid brake (MRB) with adjustable working gap is developed to improve the manufacturing accuracy and cost, and to reduce the problem of replacing the braking disc. In addition, the braking discs with three types of surface texture are designed and machined. Based on the test bed developed for the proposed MRB, a series of experiments are carried out on the manufactured prototype and the results are presented to obtain the relationship among the surface texture of the braking disc, applied current, working gap and the braking performance. The results show that the braking torque is significantly influenced by the working gap and surface texture of the braking disc, and the maximum braking torque is obtained on the conditions of 0.25 mm working gap and the braking disc with square surface texture.

  2. Electronic Brake-Force Distribution Control Methods of ABS-Equipped Vehicles During Cornering Braking

    Institute of Scientific and Technical Information of China (English)

    WANG Guo-ye; LIU Zhao-du; MA Yue-feng; QI Zhi-quan

    2007-01-01

    Based on the dynamics of ABS-equipped vehicles during cornering braking,the electronic brakeforce distribution (EBD) control methods of ABS-equipped vehicles during cornering braking are proposed.According to the dynamics and the tire model under tire adhesion limit,the stability acceptance criteria of vehicles during cornering braking are proposed.According to the stability acceptance criteria and the ABS control,the EBD control methods of ABS-equipped vehicles during cornering braking are implemented by adjusting the threshold values of tires slip independently.The vehicle states during cornering braking at two typical initial velocities of the vehicle are analyzed by the EBD control methods,whose results indicate the EBD control methods can improve the braking performances of the vehicle during cornering braking comparing with the ABS control.

  3. 14 CFR 27.735 - Brakes.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Landing Gear § 27.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the pilot... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  4. 14 CFR 29.735 - Brakes.

    Science.gov (United States)

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Landing Gear § 29.735 Brakes. For rotorcraft with wheel-type landing gear, a braking device must be installed that is— (a) Controllable by the... torque when starting or stopping the rotor; and (2) Hold the rotorcraft parked on a 10-degree slope on...

  5. Research on temperature rise of hoisting machine disk brake

    Institute of Scientific and Technical Information of China (English)

    MA Jun; JANG Hai-bo

    2012-01-01

    A mathematical model and finite element model for analysis of temperature rise of the hoisting machine brake system was constructed,limit conditions were defined,and the law of temperature rise of brake shoes during emergent brake course was analyzed and calculated by using finite element software.By analyzing the calculation results,the law of temperature change of surface of brake disk and shoes during the braking process was found.The law of brake shoes surface temperature distribution and the law of temperature change along with thickness of brake shoes at brake time 0.5 s,1.0 s and 1.5 s was analyzed.A hoisting machine emergent braking test was carried out.Finally,the author concluded that velocity rebound in the process of hoisting machine emergent brake is due to decreased friction coefficient caused by the temperature rise of the brake shoes surface.

  6. Your P.A.D. Checklist

    Science.gov (United States)

    ... turn Javascript on. Feature: Peripheral Artery Disease Your P.A.D. Checklist Past Issues / Fall 2011 Table ... and reduce your risk of peripheral artery disease (P.A.D.). That can start by making sure ...

  7. What brakes the Crab pulsar?

    CERN Document Server

    Čadež, A; Barbieri, C; Calvani, M; Naletto, G; Barbieri, M; Ponikvar, D

    2015-01-01

    Optical observations provide convincing evidence that the optical phase of the Crab pulsar follows the radio one closely. Since optical data do not depend on dispersion measure variations, they provide a robust and independent confirmation of the radio timing solution. The aim of this paper is to find a global mathematical description of Crab pulsar's phase as a function of time for the complete set of published Jodrell Bank radio ephemerides (JBE) in the period 1988-2014. We apply the mathematical techniques developed for analyzing optical observations to the analysis of JBE. We break the whole period into a series of episodes and express the phase of the pulsar in each episode as the sum of two analytical functions. The first function is the best-fitting local braking index law, and the second function represents small residuals from this law with an amplitude of only a few turns, which rapidly relaxes to the local braking index law. From our analysis, we demonstrate that the power law index undergoes "inst...

  8. 盘式制动器热应力磨损耦合行为的数值模拟%Numerical Simulation on the Coupling Behavior Between Thermal Load, Contact Stress and Wear in a Disc Brake

    Institute of Scientific and Technical Information of China (English)

    张方宇; 桂良进; 范子杰

    2014-01-01

    本文中探讨了盘式制动器制动过程中摩擦片和制动盘之间的热负荷接触应力磨损耦合行为的数值模拟方法。首先建立了盘式制动器的有限元模型;然后研究了应力磨损耦合分析的数值计算方法,并且模拟了摩擦片和制动盘的磨合过程;最后分别对热应力耦合条件下和紧急制动工况下的摩擦片磨损行为进行了模拟。结果表明,所提出的模拟方法是有效的。%The numerical simulation method of thermal load,contact stress and wear coupling behavior be-tween the pad and disk of disk brake during braking process is investigated in this paper. Firstly the finite element model for disk brake is built. Then the numerical calculation method of stress-wear coupling analysis is studied and the running-in process between pad and disk is simulated. Finally the wear behavior of brake pad in both stress-wear coupling and emergency braking conditions are simulated respectively. The results show that the simulation method proposed is effective.

  9. An Experimental Analysis of Brake Efficiency Using Four Fluids in a Drum Brake System

    Directory of Open Access Journals (Sweden)

    Prince Owusu-Ansah

    2014-06-01

    Full Text Available This paper studies drum brake failure in Mini-buses using an experimental analysis to test the viscosities and the maximum braking force when different fluids such as clean, less dirty, dirty and soapy water solution were used in the braking system. The effects of each of these fluids when successive increments in pedal force were applied at hot and cold conditions for drum brakes were studied. The results of the Thepra Universal Brake Testing Equipment used for the braking efficiency test indicated that a pedal force of 110 kN produce a brake force of 0.61 kN for clean fluid, 0.56 kN for less dirty, 0.51 kN for dirty and 0.92 kN. The value of 0.92 kN which was achieved when the soapy water solution was used indicated a positive braking force and that soap water solution could be used to produce a high pedal force within a very short time (10-30 min and can therefore be used only in case of emergency. It was observed that the clean brake fluid gave the best braking force followed by the less dirty and finally the dirty brake fluid. In a situation where air has been trapped in the system under hot condition with or without a servo unit, clean brake fluid performed much better at least three times better than the other three fluids. For soap solution, braking was effective only when it was operated at cold condition but less effective when the system was hot. Soap solution is therefore not reliable when used for a very long time but effective only for emergency situations.

  10. 基于有限元技术的汽车盘式制动器性能研究%Performance Research of Automobile Disc Brake based on Finite Element Technology

    Institute of Scientific and Technical Information of China (English)

    何亚峰

    2012-01-01

    盘式制动器由于散热性能和制动效能好等优点,被广泛应用于汽车行业中.利用大型AN-SYS有限元平台对汽车盘式制动器进行了应力应变场量数值分析,通过改变制动器设计参数(制动力、摩擦因数、制动片厚度)得到了设计参数与制动性能的影响关系,其结果可为汽车制动器设计提供一定的理论依据和参考.%Due to good cooling and braking performance, the disc brake is widely used in automotive industry. The numerical analysis of stress and strain field for automobile disc brake is carried out by using ANSYS finite element platform, ihe influence relalionship of design parameters and braking performance is obtained by changing design pa rametere of the brake (braking force, friction coefficienl, brake pad thickness), A certain theoretical basis and refer ence for the automotive brake designer is provided from the results.

  11. Peripheral Arterial Disease (P.A.D.)

    Science.gov (United States)

    ... page please turn Javascript on. Peripheral Artery Disease (P.A.D.) What is P.A.D.? Arteries Clogged With Plaque Peripheral arterial ... Escape (Esc) button on your keyboard.) Why Is P.A.D. Dangerous? Click for more information Blocked ...

  12. Study on Braking Sensation Based on Urban Working Conditions

    Directory of Open Access Journals (Sweden)

    Abi Lanie

    2017-01-01

    Full Text Available In this paper we researched the vehicle braking sense in three aspects of human, vehicle and environment and analysed their impacts on brake feeling. Through the real vehicle test we analysed the relationship among pedal force, pedal travel and deceleration. We used dynamometer test method to study the brake noise question. We designed a fixture which could imitate the suspension and made the test more close to the true level. Moreover we discussed how to establish the evaluation system of vehicle braking condition. Through real vehicle test of braking, we can test and record the brake system parameters in the braking process under urban working conditions. We recorded the brake frequency, the change of brake speed and brake disc temperature. Meanwhile, based on the analysis of braking condition, we put forward the index of brake load to reflect the city’s traffic conditions. Experiment show that the braking condition and brake feel are related, braking condition also provides theoretical support for the design of brake system.

  13. 49 CFR 570.55 - Hydraulic brake system.

    Science.gov (United States)

    2010-10-01

    ... parking brake and turn the ignition to start to verify that the brake system failure indicator lamp is... 49 Transportation 6 2010-10-01 2010-10-01 false Hydraulic brake system. 570.55 Section 570.55... 10,000 Pounds § 570.55 Hydraulic brake system. The following requirements apply to vehicles...

  14. 49 CFR 238.317 - Class II brake test.

    Science.gov (United States)

    2010-10-01

    ... locomotives that utilize an electric signal to communicate a service brake application and only a pneumatic... 49 Transportation 4 2010-10-01 2010-10-01 false Class II brake test. 238.317 Section 238.317... Requirements for Tier I Passenger Equipment § 238.317 Class II brake test. (a) A Class II brake test shall...

  15. 49 CFR 236.701 - Application, brake; full service.

    Science.gov (United States)

    2010-10-01

    ... developed. As applied to an automatic or electro-pneumatic brake with speed governor control, an application... 49 Transportation 4 2010-10-01 2010-10-01 false Application, brake; full service. 236.701 Section... § 236.701 Application, brake; full service. An application of the brakes resulting from a continuous...

  16. Dynamic characteristics of polymer faced tilting pad journal bearings

    DEFF Research Database (Denmark)

    Simmons, Gregory F.; Cerda Varela, Alejandro Javier; Santos, Ilmar

    2014-01-01

    Dynamic characteristics of polymer faced tilting pad journal bearings are presented. Investigations are conducted using a single pad, load on pad configuration over a range of shaft speeds and loads. Two polyether ether ketone (PEEK) faced pads, one polytetrafluoroethylene (PTFE) faced pad and two...... for entirely PEEK pads compared to pads with a PEEK lining and steel backing. Similar effects were observed by using a softer (PTFE) pad liner with a steel backing....

  17. A Conceptual Design Method of Disc Brake Systems for Reducing Brake Squeal Considering Pressure Distribution Variations

    OpenAIRE

    松島, 徹; 泉井, 一浩; 西脇, 眞二

    2011-01-01

    This paper proposes a design optimization method for disc brake systems that specifically aims to reduce brake squeal, with robustness against changes on contact surface pressure distribution, based on the concept of First Order Analysis. First, a simplified analysis model is constructed in which a pressure distribution parameter is introduced, and the relationships between the occurrence of brake squeal and the characteristics of various components is then clarified, using the simplified mod...

  18. Ultrasound appearance of knuckle pads

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ben, R. [Univ. of Alabama, Birmingham (United States). Dept. of Diagnostic Radiology; Dehghanpisheh, K.; Chatham, W.W.; Alarcon, G.S. [Univ. of Alabama, Birmingham (United States). Dept. of Medicine; Lee, D.H.; Oakes, J. [Univ. of Alabama, Birmingham (United States). Dept. of Surgery

    2006-11-15

    We describe the ultrasound appearance of knuckle pads. Retrospective analysis of imaging in a series of five patients initially referred for evaluation of periarticular soft-tissue swelling of the hands involving the dorsum of the PIP and MP joints. Two patients had associated Dupuytren's contractures. Ultrasound and radiographs of the hands in all patients were reviewed and correlated with clinical history and physical exams. Radiographs in four patients demonstrated dorsal soft-tissue thickening. Ultrasound exams showed increased dorsal subcutaneous thickening, with either diffuse or focal hypoechoic areas corresponding to the areas of soft-tissue fullness identified on physical exam. No erosions or synovial proliferation were identified either by radiographs or ultrasound of the underlying joints. Knuckle pads can sometimes be difficult to distinguish from synovitis on physical examination. Musculoskeletal ultrasound can quickly identify these superficial lesions and exclude underlying synovial proliferation.

  19. Thermal analysis and temperature characteristics of a braking resistor for high-speed trains for changes in the braking current

    Science.gov (United States)

    Lee, Dae-Dong; Kang, Hyun-Il; Shim, Jae-Myung

    2015-09-01

    Electric brake systems are used in high-speed trains to brake trains by converting the kinetic energy of a railway vehicle to electric energy. The electric brake system consists of a regenerative braking system and a dynamic braking system. When the electric energy generated during the dynamic braking process is changed to heat through the braking resistor, the braking resistor can overheat; thus, failures can occur to the motor block. In this paper, a braking resistor for a high-speed train was used to perform thermal analyses and tests, and the results were analyzed. The analyzed data were used to estimate the dependence of the brake currents and the temperature rises on speed changes up to 300 km/h, at which a test could not be performed.

  20. Optimal design and selection of magneto-rheological brake types based on braking torque and mass

    Science.gov (United States)

    Nguyen, Q. H.; Lang, V. T.; Choi, S. B.

    2015-06-01

    In developing magnetorheological brakes (MRBs), it is well known that the braking torque and the mass of the MRBs are important factors that should be considered in the product’s design. This research focuses on the optimal design of different types of MRBs, from which we identify an optimal selection of MRB types, considering braking torque and mass. In the optimization, common types of MRBs such as disc-type, drum-type, hybrid-type, and T-shape types are considered. The optimization problem is to find an optimal MRB structure that can produce the required braking torque while minimizing its mass. After a brief description of the configuration of the MRBs, the MRBs’ braking torque is derived based on the Herschel-Bulkley rheological model of the magnetorheological fluid. Then, the optimal designs of the MRBs are analyzed. The optimization objective is to minimize the mass of the brake while the braking torque is constrained to be greater than a required value. In addition, the power consumption of the MRBs is also considered as a reference parameter in the optimization. A finite element analysis integrated with an optimization tool is used to obtain optimal solutions for the MRBs. Optimal solutions of MRBs with different required braking torque values are obtained based on the proposed optimization procedure. From the results, we discuss the optimal selection of MRB types, considering braking torque and mass.

  1. Hunting Plan Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan provides guidelines for administration of hunting activity and for development, maintenance, and enforcement of regulations and guidelines on Morgan Brake...

  2. A statistical approach to estimate the LYAPUNOV spectrum in disc brake squeal

    Science.gov (United States)

    Oberst, S.; Lai, J. C. S.

    2015-01-01

    The estimation of squeal propensity of a brake system from the prediction of unstable vibration modes using the linear complex eigenvalue analysis (CEA) in the frequency domain has its fair share of successes and failures. While the CEA is almost standard practice for the automotive industry, time domain methods and the estimation of LYAPUNOV spectra have not received much attention in brake squeal analyses. One reason is the challenge in estimating the true LYAPUNOV exponents and their discrimination against spurious ones in experimental data. A novel method based on the application of the ECKMANN-RUELLE matrices is proposed here to estimate LYAPUNOV exponents by using noise in a statistical procedure. It is validated with respect to parameter variations and dimension estimates. By counting the number of non-overlapping confidence intervals for LYAPUNOV exponent distributions obtained by moving a window of increasing size over bootstrapped same-length estimates of an observation function, a dispersion measure's width is calculated and fed into a BAYESIAN beta-binomial model. Results obtained using this method for benchmark models of white and pink noise as well as the classical HENON map indicate that true LYAPUNOV exponents can be isolated from spurious ones with high confidence. The method is then applied to accelerometer and microphone data obtained from brake squeal tests. Estimated LYAPUNOV exponents indicate that the pad's out-of-plane vibration behaves quasi-periodically on the brink to chaos while the microphone's squeal signal remains periodic.

  3. Constraining the Braking Indices of Magnetars

    CERN Document Server

    Gao, Z F; Wang, N; Yuan, J P; Peng, Q H; Du, Y J

    2015-01-01

    Due to the lack of long term pulsed emission in quiescence and the strong timing noise, it is impossible to directly measure the braking index $n$ of a magnetar. Based on the estimated ages of their potentially associated supernova remnants (SNRs), we estimate the values of $n$ of nine magnetars with SNRs, and find that they cluster in a range of $1\\sim$41. Six magnetars have smaller braking indices of $13$ for other three magnetars are attributed to the decay of external braking torque, which might be caused by magnetic field decay. We estimate the possible wind luminosities for the magnetars with $13$ within the updated magneto-thermal evolution models. We point out that there could be some connections between the magnetar's anti-glitch event and its braking index, and the magnitude of $n$ should be taken into account when explaining the event. Although the constrained range of the magnetars' braking indices is tentative, our method provides an effective way to constrain the magnetars' braking indices if th...

  4. Brake squeal reduction of vehicle disc brake system with interval parameters by uncertain optimization

    Science.gov (United States)

    Lü, Hui; Yu, Dejie

    2014-12-01

    An uncertain optimization method for brake squeal reduction of vehicle disc brake system with interval parameters is presented in this paper. In the proposed method, the parameters of frictional coefficient, material properties and the thicknesses of wearing components are treated as uncertain parameters, which are described as interval variables. Attention is focused on the stability analysis of a brake system in squeal, and the stability of brake system is investigated via the complex eigenvalue analysis (CEA) method. The dominant unstable mode is extracted by performing CEA based on a linear finite element (FE) model, and the negative damping ratio corresponding to the dominant unstable mode is selected as the indicator of instability. The response surface method (RSM) is applied to approximate the implicit relationship between the unstable mode and the system parameters. A reliability-based optimization model for improving the stability of the vehicle disc brake system with interval parameters is constructed based on RSM, interval analysis and reliability analysis. The Genetic Algorithm is used to get the optimal values of design parameters from the optimization model. The stability analysis and optimization of a disc brake system are carried out, and the results show that brake squeal propensity can be reduced by using stiffer back plates. The proposed approach can be used to improve the stability of the vehicle disc brake system with uncertain parameters effectively.

  5. On the safety of braking mine up-haulage devices

    Energy Technology Data Exchange (ETDEWEB)

    Murzin, V.A.; Samusia, V.I.

    1982-01-01

    Experiments conducted on several mine up-haulage devices to analyze breakdowns due to the operator who quickly turned on the brake showed that sudden braking may really invoke maximum brake application on the machine winding much earlier than preventive braking and may lead to shutdown. It was concluded that in the Safety Regulations or Engineering Regulations that use of the handbrake should be more clearly outlined to preclude breakdown. One method of prevention is to develop and use a diagram showing build-up and magnitude of the braking moment when using the manual brake.

  6. Teach yourself visually iPad

    CERN Document Server

    Hart-Davis, Guy

    2013-01-01

    Fully updated coverage on the latest iPad and iPad mini! As the amazing iPad continues to evolve, so does this invaluable visual guide. Bestselling veteran author Guy Hart-Davis gets you up to date on the latest generation of the iPad, the new iPad Air, as well as the iPad mini with his clear step-by-step, image-driven guidance that is perfectly geared towards those who learn best with visual assistance. You'll get all the latest information for accessing and downloading books, apps, music, and video content as well as sending photos and e-mails, syncing with other devices and services, and

  7. Information Hiding Using Improper Frame Padding

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2010-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents interprotocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  8. 从制动副的摩擦磨损特性看陶瓷基刹车片的性能优势%The Performance Advantage of Ceramic Matrix Pods According to The Brake Pair Friction and Wear Characteristics

    Institute of Scientific and Technical Information of China (English)

    李云鹏; 邢记龙

    2011-01-01

    Automobile brake shoes material friction and wear characteristics influenced braking of safety, comfort and the replacement cycle.For the safety and reliabihty, people hope the braking deputy at high temperatures could still keep high friction coefficient (namely have enough brake friction torque). Based on the brake friction characteristics analysis and comparison, the brake deputy on the basic requirements were obtained. The good performance and development tendency of ceramic matrix pads were evaluted. The development of the automotive brake material ,plays a farreaching influence to our country.%汽车刹车片材料的摩擦磨损特性影响着车辆制动的安全性、舒适性与衬片的更换周期.从安全可靠性的角度来看,人们希望制动副在高温下仍能保持较高的摩擦系数(即有足够的制动摩擦力矩).通过对制动副摩擦磨损特性的分析,得出制动副对刹车片的基本要求,并对陶瓷基刹车片的性能优势和发展趋势作出评价,对我国汽车制动摩擦材料的发展起到了深远的影响.

  9. Braking Index of Isolated Pulsars

    CERN Document Server

    Hamil, Oliver Q; Urbanec, Martin; Urbancova, Gabriela

    2016-01-01

    Isolated pulsars are rotating neutron stars with accurately measured angular velocities $\\Omega$, and their time derivatives that show unambiguously that the pulsars are slowing down. The commonly accepted view is that it arises through emission of magnetic dipole radiation (MDR) from a rotating magnetized body. The calculated energy loss by a rotating pulsar with a constant moment of inertia is assumed proportional to a model dependent power of $\\Omega$. This relation leads to the power law $\\dot{\\Omega}$ = -K $\\Omega^{\\rm n}$ where $n$ is called the braking index. The MDR model predicts $n$ exactly equal to 3. Selected observations of isolated pulsars provide rather precise values of $n$, individually accurate to a few percent or better, in the range 1$ <$ n $ < $ 2.8, which is consistently less than the predictions of the MDR model. In spite of an extensive investigation of various modifications of the MDR model, no satisfactory explanation of observation has been found yet. The aim of this work is t...

  10. AARP iPad Tech to Connect

    CERN Document Server

    Boyd, Barbara

    2012-01-01

    The world is at your fingertips with iPad! AARP iPad: Tech to Connect introduces you to the world?s most popular tablet device, the iPad, and all the amazing things it has to offer. In clear, non-technical language, this book guides you through registering and setting up your iPad, getting acquainted with the multitouch interface, navigating around the screen, finding and downloading apps, reading books, listening to music, watching videos, surfing the web, and communicating with friends and family. Developed in partnership with AARP and dedicated to helping readers stay connected with friends

  11. iPad mini for dummies

    CERN Document Server

    Baig, Edward C

    2014-01-01

    Find out why the iPad mini has never been bigger This new edition of iPad mini For Dummies covers all the latest tips and tricks for getting an even bigger bang out of your iPad mini. Presented in full-color and written in the straightforward but fun language that has defined the For Dummies brand for more than twenty years, this friendly guide walks you through the multitouch interface, going online, getting connected, packing your iPad mini with apps, games, e-books, photos, music, and movies, synchronizing your data, texting with iMessage, working with Siri, importing pictures and launching

  12. iPad for digital photographers

    CERN Document Server

    Story, Derrick

    2013-01-01

    Discover innovative ways to strengthen your photography business with your iPad Many photographers are turning to the flexible, easy-to-use tools of the iPad and relying on them to wear a variety of hats in their photography business. Whether portable portfolio, editing tool, payment-tracking system, or appointment calendar, the iPad melds together the best attributes of the cell phone and a laptop computer and this unique book highlights them all. With this helpful resource, you'll learn how to get the most out of your iPad to not only improve your business but also enhance your p

  13. iPad 4th generation and iPad mini portable genius

    CERN Document Server

    McFedries, Paul

    2012-01-01

    Everything you need to know about the newest iPads from Apple! If you have finally decided to get in the iPad game, then don't forget to pick up the iPad's must-have accessory: your own copy of iPad 4th Generation & iPad mini Portable Genius! This hip little guide is packed with easy-to-understand tips, tricks, and advice to help you get the most out of your iPad with beautiful Retina display or the new iPad mini. You'll learn how to maximize features of the iPad, such as the Retina display, multitouch screen, FaceTime HD camera, Bluetooth and Wi-Fi +4G capability, eReader functionality, an

  14. 49 CFR 232.609 - Handling of defective equipment with ECP brake systems.

    Science.gov (United States)

    2010-10-01

    ... conventional pneumatic brakes shall not move in a freight train operating in ECP brake mode unless it would otherwise have effective and operative brakes if it were part of a conventional pneumatic brake-equipped... pneumatic brakes shall not operate with freight cars equipped with stand-alone ECP brake systems unless:...

  15. The strength of the hybrid braking calipers analysis

    Institute of Scientific and Technical Information of China (English)

    Li Weitao; Yu Haiqing; Jiang Xiaoyan

    2015-01-01

    The braking system is an important part to ensure the safety of the vehicle, so the strength analysis is essential to the brake caliper. In this article, the forces will be mixed in the caliper brake systems theoretical analysis, and based on the actual working conditions established calipers ABAQUS finite element model to simulate calipers provide a theoretical basis for the structural design of the brake caliper.

  16. A Review of a Study on Disc Brake Noise

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the development of the automotive industry, disc brake noise has become an issue of growing concern to the automotive industry and customers. In this paper, the types of disc brake noise have been discussed. Ajter that, the theories and models that have been proposed as an explanation of brake squeal are reviewed. On the basis of these theories and models, some example simulations of disc brake squeal which use the Finite Element method and mathematical model have been introduced.

  17. ACTIVE FRONT STEERING DURING BRAKING PROCESS

    Institute of Scientific and Technical Information of China (English)

    CHEN Deling; CHEN Li; YIN Chengliang; ZHANG Yong

    2008-01-01

    An active front steering (AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

  18. Hillside, Morgans Brake, and Mathews Brake National Wildlife Refuges Deer Harvest Records are from 2008 and 2014

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These harvest data are from Hillside, Morgans Brake, and Mathews Brake NWRs during the 2008 and 2014 deer seasons. They measure weight, antler size, prevalence of...

  19. Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges in 2001 and 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Biweekly Waterfowl Counts from Mathews Brake, Morgan Brake, and Hillside National Wildlife Refuges conducted from October 2001 to February 2002

  20. Central Mississippi Refuges: Yazoo, Panther Swamp, Hillside, Morgan Brake & Bathews Brake: Annual narrative report: Calendar year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Yazoo, Hillside, Panther Swamp, Morgan Brake, and Mathews Brake NWRs covers refuge activities during 2001. The report begins with a...

  1. iPads in learning

    DEFF Research Database (Denmark)

    Meyer, Bente Tobiesen

    2014-01-01

    the learning activity. This is specifically relevant when the object of study is mobile learning, where devices are flexible and follow the learner in his/her shifting learning activities and needs. This paper focuses on the ways in which iPads as learning technologies become involved in sociomaterial......Research in learning technologies has often focused on the affordances of single technologies such as pcs, smartphones or interactive whiteboards. However, in most learning environments technologies do not stand alone but are embedded in activity structures and webs of materials that make up...... practices that are emergent and improvisational and how this contributes to educational change. The paper proposes that the introduction of tablets into classrooms will enroll devices in networks of learning that establish new and significant relationships between learning technologies such as i...

  2. 49 CFR 238.319 - Running brake test.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Running brake test. 238.319 Section 238.319... Requirements for Tier I Passenger Equipment § 238.319 Running brake test. (a) As soon as conditions safely permit, a running brake test shall be performed on each passenger train after the train has received,...

  3. 49 CFR 393.40 - Required brake systems.

    Science.gov (United States)

    2010-10-01

    ... motor vehicle must meet the applicable service, parking, and emergency brake system requirements....49, and 393.52 of this subpart. (c) Parking brakes. Each commercial motor vehicle must be equipped with a parking brake system that meets the applicable requirements of § 393.41. (d) Emergency...

  4. 49 CFR 238.309 - Periodic brake equipment maintenance.

    Science.gov (United States)

    2010-10-01

    ... that all of the equipment's brake system pneumatic components that contain moving parts and are sealed... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic brake equipment maintenance. 238.309... Maintenance Requirements for Tier I Passenger Equipment § 238.309 Periodic brake equipment maintenance....

  5. 30 CFR 75.1404 - Automatic brakes; speed reduction gear.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic brakes; speed reduction gear. 75.1404... Automatic brakes; speed reduction gear. Each locomotive and haulage car used in an underground coal mine... brakes, locomotives and haulage cars shall be subject to speed reduction gear, or other similar...

  6. 49 CFR 229.57 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 229.57 Section 229.57 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Foundation brake gear. A lever, rod, brake beam, hanger, or pin may not be worn through more than 30...

  7. iPad 2 Made Simple

    CERN Document Server

    Mazo, Gary; Ritchie, Rene

    2011-01-01

    The iPad 2 is thinner, more powerful, intuitive and very fun for users of all ages. Your iPad can be used for reading, surfing the web, emailing, watching TV and movies, getting work done and much more. And with over 65,000 apps just for the iPad, as well as the ability to run over 30,000 iPhone apps, the possibilities are endless. iPad 2 Made Simple clarifies all of the key features on the iPad, introduces what's new, and also reveals dozens of time-saving shortcuts and techniques. The book has over 1,000 screen shots that are carefully annotated with step-by-step instructions. * Clear instru

  8. The braking indices in pulsar emission models

    CERN Document Server

    Wu, F; Gil, J; Gil, Janusz

    2003-01-01

    Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that the interaction between them is negligible. We suggest that it is likely that the inverse Compton scattering induced polar vacuum gap and the outer gap coexist in the pulsar magnetosphere. We include the new near threshold vacuum gap models with curvature-radiation and inverse Compton scattering induced cascades, respectively; and find that these models can well reproduce the measured values of the braking indices.

  9. Hillside, Morgan Brake, and Mathews Brake National Wildlife Refuges Reforestation Plan for 1992-1996

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan addresses the history of reforestation at Hillside National Wildlife Refuge and its two satellite refuges, Morgan Brake National Wildlife Refuge and...

  10. Study on Braking Energy Regeneration System for City Bus

    Institute of Scientific and Technical Information of China (English)

    ZOU Zheng-yao; CHEN Ru-wen; YANG Xue-mei; LIU Gou-bing; JIN Jia-jun

    2011-01-01

    Braking of the urban vehicles of public service wastes a large number of engine energy in the condition of starting and stopping frequently. Aiming at the problem, an electro-mechanical braking energy regeneration system was proposed which adopted a high-speed flywheel and a battery to recover the braking energy and achieve the secondary traction for the auxiliary start function. The system strategy was designed and the braking simulation was processed to validate its feasibility. The experiment results show that the system can effectively recover the braking energy, improve the starting performance of the city bus and it can be applied to the engineering.

  11. BRAKING PROCESS OF ENDURO AND HIGHWAY-TOURIST MOTORBIKES

    Directory of Open Access Journals (Sweden)

    Paweł SKRZYPCZYK

    2015-06-01

    Full Text Available In the event of an emergency, head of the motorcycle has a split second to decide what to do defensive maneuver. The most common choice is the braking maneuver. Starting motorcycle braking is associated with the selection of additional brake, which uses a driver. It is here to choose to use the front brake, rear or both simultaneously. The paper presents the study of the effects of such decision on the braking process. Tests were carried out for enduro and highway-tourist motorbikes.

  12. A HIGH BRAKING INDEX FOR A PULSAR

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, R. F.; Ferdman, R. D.; Kaspi, V. M.; Tendulkar, S. P. [Department of Physics and McGill Space Institute, McGill University, 3600 University Street, Montréal, QC H3A 2T8 (Canada); Gotthelf, E. V. [Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027-6601 (United States); Guillot, S. [Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 782-0436 Macul, Santiago (Chile); Harrison, F. A. [Cahill Center for Astrophysics, California Institute of Technology, 1216 East California Boulevard, Pasadena, CA 91125 (United States); Keane, E. F. [SKA Organization, Jodrell Bank Observatory, Cheshire SK11 9DL (United Kingdom); Pivovaroff, M. J. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550-9234 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Tomsick, J. A. [Space Science Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States)

    2016-03-01

    We present a phase-coherent timing solution for PSR J1640–4631, a young 206 ms pulsar using X-ray timing observations taken with NuSTAR. Over this timing campaign, we have measured the braking index of PSR J1640–4631 to be n = 3.15 ± 0.03. Using a series of simulations, we argue that this unusually high braking index is not due to timing noise, but is intrinsic to the pulsar's spin-down. We cannot, however, rule out contamination due to an unseen glitch recovery, although the recovery timescale would have to be longer than most yet observed. If this braking index is eventually proven to be stable, it demonstrates that pulsar braking indices greater than three are allowed in nature; hence, other physical mechanisms such as mass or magnetic quadrupoles are important in pulsar spin-down. We also present a 3σ upper limit on the pulsed flux at 1.4 GHz of 0.018 mJy.

  13. 30 CFR 57.14101 - Brakes.

    Science.gov (United States)

    2010-07-01

    ... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Machinery and Equipment Safety... equipped on self-propelled mobile equipment, parking brakes shall be capable of holding the equipment with... surface-operated equipment at underground mines when an MSHA inspector has reasonable cause to...

  14. Massive star models with magnetic braking

    CERN Document Server

    Meynet, Georges; Maeder, Andre

    2010-01-01

    Magnetic fields at the surface of a few early-type stars have been directly detected. These fields have magnitudes between a few hundred G up to a few kG. In one case, evidence of magnetic braking has been found. We investigate the effects of magnetic braking on the evolution of rotating ($\\upsilon_{\\rm ini}$=200 km s$^{-1}$) 10 M$_\\odot$ stellar models at solar metallicity during the main-sequence (MS) phase. The magnetic braking process is included in our stellar models according to the formalism deduced from 2D MHD simulations of magnetic wind confinement by ud-Doula and co-workers. Various assumptions are made regarding both the magnitude of the magnetic field and of the efficiency of the angular momentum transport mechanisms in the stellar interior. When magnetic braking occurs in models with differential rotation, a strong and rapid mixing is obtained at the surface accompanied by a rapid decrease in the surface velocity. Such a process might account for some MS stars showing strong mixing and low surfa...

  15. Asbestos free friction composition for brake linings

    Indian Academy of Sciences (India)

    Arnab Ganguly; Raji George

    2008-02-01

    An asbestos free friction material composite for brake linings is synthesized containing fibrous reinforcing constituents, friction imparting and controlling additives, elastomeric additives, fire retarding components and a thermosetting resin. The composite shows exemplary friction characteristics and has great resistance to wear and shows good temperature stability.

  16. NAC Off-Vehicle Brake Testing Project

    Science.gov (United States)

    2007-05-01

    Project Officer ( TIPO ) US Army National Automotive Center (NAC) Warren, MI Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden...May 2007 FinalR1 UNCLAS: Dist A. Approved for public release Leo Miller, Technology Insertion Project Officer ( TIPO ) NAC Off-vehicle Brake Testing

  17. Comparative Frictional Analysis of Automobile Drum and Disc Brakes

    Directory of Open Access Journals (Sweden)

    H.P. Khairnar

    2016-03-01

    Full Text Available In the present work, a comparative frictional behaviour of drum brakes and disc brakes in automobiles has been investigated. The influential factors; contact force and friction radius were modeled for the estimation of the friction coefficient for drum as well as disc brakes. The effect of contact force and friction radius is studied with varying conditions of parameters; longitudinal force, caliper force and torque on piston side as well as non-piston side. The numerical results obtained have been compared with the similar obtained from virtual Matlab/Simulink models for drum and disc brakes. The results evidenced that friction radius predominantly affects brake pressure and thus the friction coefficient, also the increase in contact force resulted with decrease in friction coefficient both for drum and disc brakes. Further it has been found that disc brakes exhibit gradual decrease of friction coefficient due to the equitable distribution of braking effort while drum brake presents sudden variations in friction coefficient. It can be revealed that frictional behaviour of disc brake is more consistent than drum brake.

  18. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability wer...

  19. Pedestrian injury mitigation by autonomous braking.

    Science.gov (United States)

    Rosén, Erik; Källhammer, Jan-Erik; Eriksson, Dick; Nentwich, Matthias; Fredriksson, Rikard; Smith, Kip

    2010-11-01

    The objective of this study was to calculate the potential effectiveness of a pedestrian injury mitigation system that autonomously brakes the car prior to impact. The effectiveness was measured by the reduction of fatally and severely injured pedestrians. The database from the German In-Depth Accident Study (GIDAS) was queried for pedestrians hit by the front of cars from 1999 to 2007. Case by case information on vehicle and pedestrian velocities and trajectories were analysed to estimate the field of view needed for a vehicle-based sensor to detect the pedestrians one second prior to the crash. The pre-impact braking system was assumed to activate the brakes one second prior to crash and to provide a braking deceleration up to the limit of the road surface conditions, but never to exceed 0.6 g. New impact speeds were then calculated for pedestrians that would have been detected by the sensor. These calculations assumed that all pedestrians who were within a given field of view but not obstructed by surrounding objects would be detected. The changes in fatality and severe injury risks were quantified using risk curves derived by logistic regression of the accident data. Summing the risks for all pedestrians, relationships between mitigation effectiveness, sensor field of view, braking initiation time, and deceleration were established. The study documents that the effectiveness at reducing fatally (severely) injured pedestrians in frontal collisions with cars reached 40% (27%) at a field of view of 40 degrees. Increasing the field of view further led to only marginal improvements in effectiveness.

  20. Modeling and design of cooperative braking in electric and hybrid vehicles using induction machine and hydraulic brake

    Directory of Open Access Journals (Sweden)

    Zaini Dalimus

    2016-07-01

    Full Text Available In mixed-mode braking applications, the electric motor / generator (M/G and hydraulic pressure valve are controlled to meet the driver’s braking demand. Controlling these braking elements is achieved by modulating the current generated by the M/G and adjusting the fluid pressure to the wheel brake cylinders. This paper aims to model and design combined regenerative and hydraulic braking systems which, comprise an induction electric machine, inverter, NiMH battery, controller, a pressure source, pressure control unit, and brake calipers. A 15 kW 1500 rpm induction machine equipped with a reduction gear having a gear ratio of 4 is used. A hydraulic brake capable to produce fluid pressure up to 40 bar is used. Direct torque control and pressure control are chosen as the control criteria in the M/G and the hydraulic solenoid valve. The braking demands for the system are derived from the Federal Testing Procedure (FTP drive cycle. Two simulation models have been developed in Matlab®/Simulink® to analyze the performance of the control strategy in each braking system. The developed model is validated through experiment. It is concluded that the control system does introduce torque ripple and pressure oscillation in the braking system, but these effects do not affect vehicle braking performance due to the high frequency nature of pressure fluctuation and the damping effect of the vehicle inertia. Moreover, experiment results prove the effectiveness of the developed model.

  1. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  2. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric-pressure plasma technology. Compared to...

  3. Plasma Air Decontamination System (PADS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric pressure plasma technology that operates...

  4. iPad application development for dummies

    CERN Document Server

    Goldstein, l

    2012-01-01

    The fun and easy guide to creating iPad apps, updated for iOS 5! iPad app development is hot, with more than 140,000 apps available specifically for the device and that number growing every day. The introduction of iOS 5 and iCloud gives developers even more options to create incredible iPad apps. This fast and friendly guide to iPad app development is fully updated for the most recent upgrades and covers everything you need to know, starting with how to download the SDK and become an Apple developer all the way to finishing up your app and submitting it to the App Store. Zeroes in on essentia

  5. iPad 2 The Missing Manual

    CERN Document Server

    Biersdorfer, JD

    2011-01-01

    With iOS 5, Apple added more than 200 new features to the iPad 2, but there's still no printed guide to using all its amazing capabilities. That's where this full-color Missing Manual comes in. You'll learn how to stuff your iPad with media, organize your personal life, wirelessly stream content to and from your tablet, stay connected to friends, and much more. The important stuff you need to know: Build your media library. Fill your iPad with music, movies, TV shows, eBooks, eMagazines, photos, and more.Go wireless. Sync content between your computer and iPad-no wires needed.Get online. Con

  6. iPad for the older and wiser get up and running with your Apple iPad, iPad Air and iPad Mini

    CERN Document Server

    McManus, Sean

    2013-01-01

    Apple's iPad puts a limitless world of entertainment, communication, and everyday functionality in the palms of your hands. iPad for the Older and Wiser, 4th Edition quickly teaches you how to make the most of your new gadget with easy-to-follow instructions. Fully updated to include the iPad Air and iOS 7, this step-by-step guide shows you exactly how to set up your device and discover what it can do - all in jargon-free language. Learn how to: Set up your iPad and copy music and photos from your computerKeep in touch with email and messagesBrowse the web and shop onlineHave video chats wi

  7. Exploring iPad 2 For Dummies

    CERN Document Server

    Gruman, Galen

    2011-01-01

    Making iPad Easier! The iPad combines the best of your favorite gadgets into one amazing ultraportable touch device. And this cool guide is your one-stop resource for making the most of your iPad 2 or iPad and all it has to offer! Let your fingers lead the wayLearn to navigate the multitouch screen, surf the web, view maps, and even get driving directions, all with a simple touch. That's entertainmentListen to your favorite tunes, watch videos, unwind with a great book, video chat with FaceTime, and find apps to indulge your interests. Take your best shotShoot HD videos and photos, add awesome

  8. Pad B Liquid Hydrogen Storage Tank

    Science.gov (United States)

    Hall, Felicia

    2007-01-01

    Kennedy Space Center is home to two liquid hydrogen storage tanks, one at each launch pad of Launch Complex 39. The liquid hydrogen storage tank at Launch Pad B has a significantly higher boil off rate that the liquid hydrogen storage tank at Launch Pad A. This research looks at various calculations concerning the at Launch Pad B in an attempt to develop a solution to the excess boil off rate. We will look at Perlite levels inside the tank, Boil off rates, conductive heat transfer, and radiant heat transfer through the tank. As a conclusion to the research, we will model the effects of placing an external insulation to the tank in order to reduce the boil off rate and increase the economic efficiency of the liquid hydrogen storage tanks.

  9. [Mechanical buffering characteristics of feline paw pads].

    Science.gov (United States)

    Zhang, Xiaopeng; Yang, Jialing; Yu, Hui

    2012-12-01

    In the long time of natural evolution, the bodies of some animals, such as feline, that live in the wild and complicate surroundings have evolved to possess outstanding buffering characteristics, which make the animals adapt to the environment perfectly. These animals generally have well-developed paw pads under their soles to play an important role in attenuating the intensity of impact when they land on the ground. Investigating the buffering characteristics of these animals' paw pads could help us to design "bionic" buffering and energy-absorption devices. In this paper, based on observations of animal jumping test, a simple mass-spring-buffer model was proposed to explore the buffering characteristics of the animals' paw pads. By analytically solving the differential equations of this model, the parameters concerned with paw pads functions were discussed and some significant results were obtained.

  10. iPad & Siri for dummies

    CERN Document Server

    Baig, Edward C

    2012-01-01

    Two complete e-books on using iPad and Siri for one low price! This unique value-priced e-book set brings together two bestselling For Dummies books in a single e-book file. Including a comprehensive table of contents and the full text of each book, complete with cover, this e-book set helps you get the most out of your iPad and Siri, its artificial intelligence personal assistant. Best of all, you'll pay less than the cost of each book purchased separately. You'll get the complete text of: iPad For Dummies, which helps you toSet up your iPad, browse the

  11. Simulation and analysis of vehicle stability based on ADAMS/CAR differential brake

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To improve the braking safety of automobiles, the author studied the effect of differential brake on the stabilities. To analyze the mechanical characteristics of differential brake, automotive subsystem models were built by applying ADAMS/CAR, and automotive mechanics simulation model was built by setting the main subsystems such as body, engine and brake. The simulation model studied the distribution mode of three kinds of differential brake, and beeline braking stability and turning braking stability were simulated. It shows that differential brake can amend turning shortage of automobile brake and improve its braking stability, but the effect of automobile mass on its braking stability is great. So the distribution mode of braking force and the effect of mass change should be considered while differential brake is applied.

  12. Enter the iPad (or Not?)

    Science.gov (United States)

    Waters, John K.

    2010-01-01

    Few computing devices have sparked the burning gizmo lust ignited by the iPad. Apple's latest entry into the tablet PC market didn't generate much heat when it was first unveiled in January, but by April 3, the day of the official release, feverish customers were mobbing Apple stores. The company claims to have sold 300,000 iPads by midnight on…

  13. IT Does Not Love iPads

    Science.gov (United States)

    Fredette, Michelle

    2013-01-01

    On many campuses, iPads have taken over the hearts and minds of everyone. Everyone, that is, except the IT department. These sexy tablets might be the apple of faculty and students' eyes, but for IT directors and their staffs, working with iPads in an enterprise network environment is not the stuff of a love affair. To state the problem…

  14. Heavy Metal Pad Shielding during Fluoroscopic Interventions

    OpenAIRE

    Dromi, Sergio; Wood, Bradford J.; Oberoi, Jay; Neeman, Ziv

    2006-01-01

    Significant direct and scatter radiation doses to patient and physician may result from routine interventional radiology practice. A lead-free disposable tungsten antimony shielding pad was tested in phantom patients during simulated diagnostic angiography procedures. Although the exact risk of low doses of ionizing radiation is unknown, dramatic dose reductions can be seen with routine use of this simple, sterile pad made from lightweighttungsten antimony material.

  15. An Intelligent Regenerative Braking Strategy for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Zhibin Song

    2011-09-01

    Full Text Available Regenerative braking is an effective approach for electric vehicles (EVs to extend their driving range. A fuzzy-logic-based regenerative braking strategy (RBS integrated with series regenerative braking is developed in this paper to advance the level of energy-savings. From the viewpoint of securing car stability in braking operations, the braking force distribution between the front and rear wheels so as to accord with the ideal distribution curve are considered to prevent vehicles from experiencing wheel lock and slip phenomena during braking. Then, a fuzzy RBS using the driver’s braking force command, vehicle speed, battery SOC, battery temperature are designed to determine the distribution between friction braking force and regenerative braking force to improve the energy recuperation efficiency. The experimental results on an “LF620” prototype EV validated the feasibility and effectiveness of regenerative braking and showed that the proposed fuzzy RBS was endowed with good control performance. The maximum driving range of LF620 EV was improved by 25.7% compared with non-RBS conditions.

  16. 21 CFR 884.5435 - Unscented menstrual pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Unscented menstrual pad. 884.5435 Section 884.5435... § 884.5435 Unscented menstrual pad. (a) Identification. An unscented menstrual pad is a device that is a pad made of cellulosic or synthetic material which is used to absorb menstrual or other...

  17. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232... Train brake tests conducted using yard air. (a) When a train air brake system is tested from a yard air... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The...

  18. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  19. Impacts of iPad attributes, Lifestyles and media dependency on adoption of iPad and intensity of iPad usage in Mainland China

    OpenAIRE

    2012-01-01

    The goal of this exploratory research is to identify attributes that can distinctly characterize iPad and examine the predictive power of iPad attributes, lifestyles, media dependency, and demographics on adoption of iPad, iPad usage patterns and intensity of iPad usage. Using a snowballing sample, an online survey was conducted with 623 university students in Mainland China, among which 217 were iPad users and 406 were non-users. Results of regression analyses show that application affordanc...

  20. Plasma Braking Due to External Magnetic Perturbations

    Science.gov (United States)

    Frassinetti, L.; Olofsson, Kejo; Brunsell, P. R.; Khan, M. W. M.; Drake, J. R.

    2010-11-01

    The RFP EXTRAP T2R is equipped with a comprehensive active feedback system (128 active saddle coils in the full-coverage array) and active control of both resonant and non-resonant MHD modes has been demonstrated. The feedback algorithms, based on modern control methodology such as reference mode tracking (both amplitude and phase), are a useful tool to improve the ``state of the art'' of the MHD mode control. But this tool can be used also to improve the understanding and the characterization of other phenomena such as the ELM mitigation with a resonant magnetic perturbation or the plasma viscosity. The present work studies plasma and mode braking due to static RMPs. Results show that a static RMP produces a global braking of the flow profile. The study of the effect of RMPs characterized by different helicities will also give information on the plasma viscosity profile. Experimental results are finally compared to theoretical models.

  1. A high performance pneumatic braking system for heavy vehicles

    Science.gov (United States)

    Miller, Jonathan I.; Cebon, David

    2010-12-01

    Current research into reducing actuator delays in pneumatic brake systems is opening the door for advanced anti-lock braking algorithms to be used on heavy goods vehicles. However, these algorithms require the knowledge of variables that are impractical to measure directly. This paper introduces a sliding mode braking force observer to support a sliding mode controller for air-braked heavy vehicles. The performance of the observer is examined through simulations and field testing of an articulated heavy vehicle. The observer operated robustly during single-wheel vehicle simulations, and provided reasonable estimates of surface friction from test data. The effect of brake gain errors on the controller and observer are illustrated, and a recursive least squares estimator is derived for the brake gain. The estimator converged within 0.3 s in simulations and vehicle trials.

  2. Elastoplastic finite element analysis for wet multidisc brake during lasting braking

    Directory of Open Access Journals (Sweden)

    Ji Zhanling

    2015-01-01

    Full Text Available Addressed to serious heat degradation problem of the braking continuously performed in the drag brake application for a long time, finite element analysis for bidirectional thermal-structure coupling is adopted to investigate temperature and stress when material properties are temperature-dependent. Based on the constitutive relations of heat transfer and strain-stress, three-dimensional transient finite element equilibrium equations with many kinds of boundary conditions for bidirectional thermal-structure coupling were derived. And it was originally presented that start time, location, severity and evolution laws of plastic deformation were depicted using dimensionless stress distribution contour with the yield limit related to temperature. The change laws of plastic element number and contact area versus braking time were expressed by plasticity ratio and contact ratio curves, respectively. The laws revealed by the numerical calculation results are in accordance with the objective perception and reasoning.

  3. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle.

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  4. Development of Anti-lock Braking System (ABS) for Vehicles Braking

    Science.gov (United States)

    Minh, Vu Trieu; Oamen, Godwin; Vassiljeva, Kristina; Teder, Leo

    2016-11-01

    This paper develops a real laboratory of anti-lock braking system (ABS) for vehicle and conducts real experiments to verify the ability of this ABS to prevent the vehicle wheel from being locked while braking. Two controllers of PID and fuzzy logic are tested for analysis and comparison. This ABS laboratory is designed for bachelor and master students to simulate and analyze performances of ABS with different control techniques on various roads and load conditions. This paper provides educational theories and practices on the design of control for system dynamics.

  5. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    OpenAIRE

    Jian-ping Wen; Chuan-wei Zhang

    2015-01-01

    In order to improve energy utilization rate of battery-powered electric vehicle (EV) using brushless DC machine (BLDCM), the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO) to observe actual braking current and the unknown disturbances of regenerative braking system, ...

  6. iPad For Seniors For Dummies

    CERN Document Server

    Muir, Nancy C

    2010-01-01

    The full-color guide to the exciting new iPad, written specifically with the needs of seniors in mind!. The iPad is the perfect device for the senior market, combining the Web, e-mail, photos, video, and book reading into an intuitive, portable device. Written by veteran Dummies author Nancy Muir, this fun and friendly guide shows you how to use the many features and capabilities of the iPad to make life easier! You'll learn how to use the multitouch screen to zoom in and out on Web pages and choose a font and size that makes reading comfortable so that you can get directions, plan vacations,

  7. iPad The Missing Manual

    CERN Document Server

    Biersdorfer, J

    2010-01-01

    The iPad 2 is faster, lighter, and more versatile than its predecessor, but there's still no printed guide to using its amazing features. That's where this full-color Missing Manual comes in. Learn how to stream HD video, make video calls, manage your email, surf the Web, listen to music, play games, and maybe even do a little iWork. This is the book that should have been in the box. Build your media library. Fill your iPad with music, movies, TV shows, eBooks, photos, and more.Share with others. Stream music, HD movies, TV shows, and more, to and from your iPad.Create your own media. Use the

  8. Teach Yourself VISUALLY iPad

    CERN Document Server

    Watson, Lonzell

    2010-01-01

    An ideal, visual guide for the image-driven iPad. Whether your interests veer towards movies, games, books, or music—the iPad is the computing device for dazzling graphics, crisp and clear audio, and effortless portability. If ever there existed a device that demanded a reading companion for the visual learner, it's the iPad—and this resource is perfectly suited for the visual audience. Veteran VISUAL author Lonzell Watson walks you through all the features unique to the iPad and shows you how to download books, apps, music, and video content, as well as send photos and e-mails. Plus, you'll d

  9. 17 Pseudoaneurysms Treated by Padding and Compression

    Institute of Scientific and Technical Information of China (English)

    WANGLu-ping; MEIXiao-rong; XUYu-lan; LIUYi; ZHENGCheng-fei; WANGGang

    2004-01-01

    To introduce the method and curative effect of treating pseudoaneurysms by padding and compression. Method: retrospectively analyze the curative effect of treating 17 pseudoaneurysms bypadding hard things and compression. Result: 15 of them was completely recovered by doing so,murmur disappeared and the local skin became even, there was no recurrences and complications after 0.5-3year's following up,but the other two were the same as before the therapy. Conclusion: pseudoaneurysms can be treated effectively by padding and compression

  10. Exploring iPad For Dummies

    CERN Document Server

    Gruman, Galen

    2012-01-01

    What the book covers: Meet the iPad, getting connected, syncing files, searching your iPad, running apps, navigating the multitouch interface, taking a web Safari, setting up e-mail, sharing through e-mail, twitter, or Message, admiring pictures, showing slideshows, taking pictures and video, making video calls with FaceTime, playing your tunes, exploiting playlists, buying music, getting organized with contacts, calendars, and reminders, taking notes, discovering productivity apps, staying connected with Notification Center, locating anything with Maps, finding and watching videos, streaming

  11. A novel highly flexible, simple, rapid and low-cost fabrication tool for paper-based microfluidic devices (μPADs) using technical drawing pens and in-house formulated aqueous inks.

    Science.gov (United States)

    Nuchtavorn, Nantana; Macka, Mirek

    2016-05-05

    Paper-based microfluidic devices (μPADs) are capable of achieving rapid quantitative measurements of a variety of analytes inexpensively. μPADs rely on patterning hydrophilic-hydrophobic regions on a sheet of paper in order to create capillary channels within impermeable fluidic brakes on the paper. Here, we present a novel, highly flexible and low-cost fabrication method using a desktop digital craft plotter/cutter and technical drawing pens with tip size of 0.5 mm. The pens were used with either commercial black permanent ink for drawing fluidic brakes, or with specialty in-house formulated aqueous inks. With the permanent marker ink it was possible to create barriers on paper rapidly and in a variety of designs in a highly flexible manner. For instance, a design featuring eight reservoirs can be produced within 10 s for each μPAD with a consistent line width of brakes (%RSD < 1.5). Further, we investigated the optimal viscosity range of in-house formulated inks controlled with additions of poly(ethylene glycol). The viscosity was measured by capillary electrophoresis and the optimal viscosity was in the range of ∼3-6 mPa s. A functional test of these μPADs was conducted by the screening of antioxidant activity. Colorimetric measurements of flavonoid, phenolic compounds and DPPH free radical scavenging activity were carried out on μPADs. The results can be detected by the naked eye and simply quantified by using a camera phone and image analysis software. The fabrication method using technical drawing pens provides flexibility in the use of in-house formulated inks, short fabrication time, simplicity and low cost.

  12. Quality control of cast brake discs

    Directory of Open Access Journals (Sweden)

    M. Stawarz

    2008-04-01

    Full Text Available The largest industrial application so far have the gray cast irons which are characterized by low tensile and bending strength, while at the same time they have good ultimate comprehensive strength. Additionally, the fatigue strength of gray cast irons is comparatively low and they are only to some extend sensitive for the surface waters effects. Cast iron is the material, which is comparatively easy to be processed, and for this reason – it is not expensive. Brake discs are exploited in particularly hard conditions. They must be resistant both against the thermal fatigue and abrasion wearing (at dry friction as well as against seizing, corrosion and mechanical load [1-3]. The gray cast iron, better than other materials, fulfills all the requirements necessary for making the material for the casts resistant against such tough conditions. This work reflects the researches aiming to define the quality of cast brake discs (ventilated and non-ventilated ones upon a period of their exploitation in real conditions. The following researches were performed: evaluations of the disc surface condition, measurement of disc thickness, examination of run – out flank and metallographic analysis. In order to more detailed recognition of mechanisms and reasons of brake discs wearing in real conditions, one should conduct additional examinations: computer analysis of the microstructure, chemical composition analysis, etc., as well as study of the technology of their production in foundries, where they are manufactured [4]. By obtaining the full set of the mentioned above data one can draw final conclusions and remove causes of possible defects.

  13. THE THEORETICAL MODEL FOR PREDICTING CIRCULATION VELOCITY OF HYDRAULIC BRAKE

    Institute of Scientific and Technical Information of China (English)

    刘英林; 侯春生

    1997-01-01

    By rational hypothesis of fluid flow pattern, applied the law of conservation of energy and integrated the laboratory test results, finished the prediction by the theoretical model of circulation velocity of hydraulic brake which is important parameter. Thus provide the theoritical basis for hydraulic brake of belt conveyor whose research has just been started.

  14. Ileal brake activation: Macronutrient-specific effects on eating behavior?

    NARCIS (Netherlands)

    Avesaat, M. van; Troost, F.J.; Ripken, D.; Hendriks, H.F.; Aam, M.

    2015-01-01

    BACKGROUND: Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown. OBJECTIVE: The objective of t

  15. Characterisation of motorcyclist's upper body motion during braking manoeuvre

    NARCIS (Netherlands)

    Ioannis, S.; Kavadarli, G.; Fraga, F.; Rooij, L. van; Schuller, E.; Peldschus, S.

    2010-01-01

    Motorcycle braking experiments with volunteers were performed in lab, to study the body posture and reactions of the motorcyclists during braking with the aim of providing input for human modelling. Human motion capture methods were employed for the kinematics and the recorded data was further analy

  16. Development of a multi-pole magnetorheological brake

    Science.gov (United States)

    Shiao, Yaojung; Nguyen, Quang-Anh

    2013-06-01

    This paper presents a new approach in the design and optimization of a novel multi-pole magnetorheological (MR) brake that employs magnetic flux more effectively on the surface of the rotor. MR brakes with conventional single ring-type electromagnetic poles have reached the limits of torque enhancement. One major reason is the limitation of the magnetic field strength within the active area of the MR fluid due to the geometric constraints of the coil. The multi-pole MR brake design features multiple electromagnetic poles surrounded by several coils. As a result, the active chaining areas for the MR fluid are greatly increased, and significant brake torque improvement is achieved. The coil structure, as a part of the stator, becomes flexible and customizable in terms of space usage for the winding and bobbin design. In addition, this brake offers extra options in its dimensions for torque enhancement because either the radial or the axial dimensions of the rotor can be increased. Magnetic circuit analysis was conducted to analyze the effects of the design parameters on the field torque. After that, simulations were done to find the optimal design under all major geometric constraints with a given power supply. The results show that the multi-pole MR brake provides a considerable braking torque increase while maintaining a compact and solid design. This is confirmation of its feasibility in actual braking applications.

  17. 49 CFR 393.48 - Brakes to be operative.

    Science.gov (United States)

    2010-10-01

    ...) The steering axle of a three-axle dolly which is steered by a co-driver; (5) Loaded house moving... times be capable of operating. (b) Devices to reduce or remove front-wheel braking effort. A commercial motor vehicle may be equipped with a device to reduce the front wheel braking effort (or in the case...

  18. Ileal brake activation: macronutrient-specific effects on eating behavior?

    NARCIS (Netherlands)

    Avesaat, van M.; Troost, F.J.; Ripken, D.; Hendriks, H.F.; Masclee, A.A.M.

    2015-01-01

    Background:Activation of the ileal brake, by infusing lipid directly into the distal part of the small intestine, alters gastrointestinal (GI) motility and inhibits food intake. The ileal brake effect on eating behavior of the other macronutrients is currently unknown.Objective:The objective of this

  19. Report of a family with idiopathic knuckle pads and review of idiopathic and disease-associated knuckle pads.

    Science.gov (United States)

    Hyman, Charles H; Cohen, Philip R

    2013-05-15

    Knuckle pads are a rare, frequently overlooked, thickening of the skin usually overlying the extensor surface of the proximal interphalangeal joints. They are well- circumscribed, benign lesions that generally do not require treatment. Idiopathic knuckle pads must be differentiated from similar appearing lesions or trauma-induced pseudo-knuckle pads. Knuckle pads have been observed in association with autosomal dominant conditions such as Bart-Pumphrey syndrome, Dupuytren's contracture, Ledderhose disease, and Peyronie's disease. To the best of our knowledge, idiopathic familial knuckle pads have not previously been described in the English language literature. We describe a sister and brother with familial idiopathic knuckle pads with no associated conditions.

  20. Do foot pad scores measure Turkey welfare

    NARCIS (Netherlands)

    Hocking, P.M.; Harkness, A.; Veldkamp, Teun; Vinco, L.J.

    2017-01-01

    The main aim of the project was to assess the painfulness of different levels of foot pad dermatitis (FPD) in turkeys. Three different analgesics (butorphanol, carprofen and meloxicam) were used to assess their effect on behaviour. Video recordings were taken when the birds were treated with either

  1. Er iPad digital udeskole?

    DEFF Research Database (Denmark)

    Schilhab, Theresa

    2014-01-01

    Hvor ’konkret’ skal en oplevelse være, for at intuitionen om, at det selvoplevede styrker læringen, holder? Er brug af tablets (e.g. iPads) et ligebyrdigt alternativ til den konkrete oplevelse?...

  2. DATA TRANSLATION BETWEEN PADS AND CAM350

    Directory of Open Access Journals (Sweden)

    E. B. Romanova

    2015-07-01

    Full Text Available The subject matter of the paper is the process of data translation between computer-aided design system for electronic devices PADS VX and system for technological preparation of production of printed circuit boards CAM350 10. The object of this study is two-way translation of data in these systems. Experimental researches are applied as research methods based on repeated playback of forward and reverse data translation process between PADS and CAM350 systems. The aim is to examine the challenges of data exchange between systems and to find out the ways of their solution. The basis of the work is functionality analysis of PADS and CAM350 systems while data translation, which was carried out in the course of operating experience of these systems. The paper presents advantages and disadvantages of translation methods and their comparison. Errors arising in the process are analyzed. Possible reasons of errors origination are described. The main results are recommendations for data exchange between PADS and CAM350 systems. The proposed recommendations give the possibility to optimize the exchange of data between these systems. Practical significance of the work lies in the implementation of results at LLC «Abeo». Recommendations have been used in the development of dozens of different electronic devices. The use of these results made it possible to reduce the production run-up time, to increase data transmission correctness, thereby improving the quality of products and reduction of their cost.

  3. A Comparative Study on Automotive Brake Testing Standards

    Science.gov (United States)

    Kumbhar, Bhau Kashinath; Patil, Satyajit Ramchandra; Sawant, Suresh Maruti

    2016-06-01

    Performance testing of automotive brakes involves determination of stopping time, distance and deceleration level. Braking performance of an automobile is required to be ensured for various surfaces like dry, wet, concrete, bitumen etc. as well as for prolonged applications. Various brake testing standards are used worldwide to assure vehicle and pedestrian safety. This article presents methodologies used for automotive service brake testing for two wheelers. The main contribution of this work lies in comparative study of three main brake testing standards; viz. Indian Standards, Federal Motor Vehicle Safety Standards and European Economic Commission Standards. This study shall help the policy makers to choose the best criteria out of these three while formulating newer edition of testing standards.

  4. Parity space-based fault diagnosis of CCBII braking system

    Institute of Scientific and Technical Information of China (English)

    黄志武; 杨迎泽; 王晶; 李赟

    2013-01-01

    Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faults. A parity space-based method was proposed for fault diagnosis of CCBII braking systems. Firstly, the mathematical models were established according to three function modules of CCBII braking systems where the air fluid theory was utilized. Then, parity vector and threshold function were designed for each output of the system so as to identify more system faults. Fault character matrix was built based on the causal relationship between the output and the fault according to the system function and internal structure. Finally, fault detection and isolation can be realized by the comparison of the observed system output and the fault character matrix. Simulation results show that the proposed method is entirely feasible and effective.

  5. Design optimization of a magnetorheological brake in powered knee orthosis

    Science.gov (United States)

    Ma, Hao; Liao, Wei-Hsin

    2015-04-01

    Magneto-rheological (MR) fluids have been utilized in devices like orthoses and prostheses to generate controllable braking torque. In this paper, a flat shape rotary MR brake is designed for powered knee orthosis to provide adjustable resistance. Multiple disk structure with interior inner coil is adopted in the MR brake configuration. In order to increase the maximal magnetic flux, a novel internal structure design with smooth transition surface is proposed. Based on this design, a parameterized model of the MR brake is built for geometrical optimization. Multiple factors are considered in the optimization objective: braking torque, weight, and, particularly, average power consumption. The optimization is then performed with Finite Element Analysis (FEA), and the optimal design is obtained among the Pareto-optimal set considering the trade-offs in design objectives.

  6. Prevent P.A.D.: Know Your Numbers

    Science.gov (United States)

    ... Home Current Issue Past Issues Special Section Prevent P.A.D.: Know Your Numbers Past Issues / Summer ... By Mary Best "Timely detection and treatment of P.A.D. are critical," says Dr. Patrice Desvigne- ...

  7. Design and Analysis of Electro-mechanical Hybrid Anti-lock Braking System for Hybrid Electric Vehicle Utilizing Motor Regenerative Braking

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jianlong; YIN Chengliang; ZHANG Jianwu

    2009-01-01

    Braking on low adhesion-coefficient roads, hybrid electric vehicle's motor regenerative torque is switched off to safeguard the normal anti-lock braking system (ABS) function. When the ABS control is terminated, the motor regenerative braking is readmitted.Aiming at avoiding permanent cycles from hydraulic anti-lock braking to motor regenerative braking, a novel electro-mechanical hybrid anti-lock braking system using fuzzy logic is designed. Different from the traditional single control structure, this system has a two-layered hierarchical structure. The first layer is responsible for harmonious adjustment or interaction between regenerative system and anti-lock braking system. The second layer is responsible for braking torque distribution and adjustment. The closed-loop simulation model is built. Control strategy and method for coordination between regenerative and anti-lock braking are developed. Simulation braking on low adhesion-coefficient roads with fuzzy logic control and real vehicle braking field test are presented. The results from simulating analysis and experiment show braking performance of the vehicle is perfect, harmonious coordination between regenerative and anti-lock braking function, significant amount of braking energy can be recovered and the proposed control strategy and method are effective.

  8. PROTOBINARY EVOLUTION DRIVEN BY MAGNETIC BRAKING

    Science.gov (United States)

    Zhao, Bo; Li, Z.; Kratter, K. M.

    2014-01-01

    The majority of stars are in multiple systems, especially binaries. Such objects form in dense cores of molecular clouds that are observed to be strongly magnetized. Most previous studies of binary formation have either ignored magnetic fields or focused on the initial core fragmentation into binary seeds. Here I focus on the effects of the magnetic field on the orbital evolution of the protobinary during the main accretion phase, after a pair of stellar seeds have formed. By simulating a 'seed' binary system with the sink particle treatment, we show that magnetic field plays a crucial role in removing the gas angular momentum and shrinking the binary separation. Through magnetic braking, strong magnetic field is very effective in suppressing the formation of circumstellar disks and circumbinary disk along with its spiral arm structures. The magnetic field can also be responsible for the population of the low mass-ratio binaries in the observed distribution. The magnetically-braked material will have equal chance of being accreted onto either binary seed, instead of the preferential accretion onto the secondary when magnetic field is absent. Furthermore, large field mis-alignment helps to produce rotationally-supported circumbinary disks even for relatively strong magnetic fields, by weakening the magnetically-dominated structure close to the binary. Hence to explain the observed properties of binaries, the magnetic effects deserve more careful considerations in the larger context of binary formation in future studies.

  9. Simulation study of the plasma brake effect

    CERN Document Server

    Janhunen, Pekka

    2014-01-01

    The plasma brake is a thin negatively biased tether which has been proposed as an efficient concept for deorbiting satellites and debris objects from low Earth orbit. We simulate the interaction with the ionospheric plasma ram flow with the plasma brake tether by a high performance electrostatic particle in cell code to evaluate the thrust. The tether is assumed to be perpendicular to the flow. We perform runs for different tether voltage, magnetic field orientation and plasma ion mass. We show that a simple analytical thrust formula reproduces most of the simulation results well. The interaction with the tether and the plasma flow is laminar when the magnetic field is perpendicular to the tether and the flow. If the magnetic field is parallel to the tether, the behaviour is unstable and thrust is reduced by a modest factor. The case when the magnetic field is aligned with the flow can also be unstable, but does not result in notable thrust reduction. We also fix an error in an earlier reference. According to...

  10. PsyPad: a platform for visual psychophysics on the iPad.

    Science.gov (United States)

    Turpin, Andrew; Lawson, David J; McKendrick, Allison M

    2014-03-11

    This article introduces PsyPad, a customizable, open-source platform for configuring and conducting visual psychophysics experiments on iPads without the need for any code development for the iPad. Stimuli for experiments are created off-line as a library of images. The PsyPad app (obtainable from the Apple App Store) presents the images according to either built-in, customizable staircase or method of constant stimuli procedures, mapping stimuli levels to images based on the image file names. On-screen buttons for responses are configurable and matched to "correct" using the image file name of any given stimulus. All actions are logged into a text file and sent to a specified server at the end of the test if an Internet connection is available. If the iPad is not connected, the results are uploaded the next time the iPad is online. We provide a secure server for this purpose, but the server-side software is also open source if researchers choose to run their own server.

  11. 21 CFR 880.5270 - Neonatal eye pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neonatal eye pad. 880.5270 Section 880.5270 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... § 880.5270 Neonatal eye pad. (a) Identification. A neonatal eye pad is an opaque device used to...

  12. 21 CFR 890.5740 - Powered heating pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered heating pad. 890.5740 Section 890.5740...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5740 Powered heating pad. (a) Identification. A powered heating pad is an electrical device intended for medical...

  13. iPads in Higher Education--Hype and Hope

    Science.gov (United States)

    Nguyen, Lemai; Barton, Siew Mee; Nguyen, Linh Thuy

    2015-01-01

    This paper systematically reviews current research on using iPads in the higher education sector. Since the release of iPads by Apple in 2010, this new technology has been quickly adopted everywhere, especially by the younger generation and professionals. We were motivated to find out how iPads have been adopted for use in the higher education…

  14. 49 CFR 232.211 - Class III brake tests-trainline continuity inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class III brake tests-trainline continuity... § 232.211 Class III brake tests-trainline continuity inspection. (a) A Class III brake test shall be... configuration of the train has changed in certain ways. In particular, a Class III brake test shall be...

  15. 49 CFR 232.103 - General requirements for all train brake systems.

    Science.gov (United States)

    2010-10-01

    ... pneumatic technology, the integrity of the train line shall be monitored by the brake control system. (c) A... straight air brake 30-50 (7) Self-lapping portion for electro-pneumatic brake (minimum full application... 49 Transportation 4 2010-10-01 2010-10-01 false General requirements for all train brake...

  16. Research on Modeling and Control of Regenerative Braking for Brushless DC Machines Driven Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Jian-ping Wen

    2015-01-01

    Full Text Available In order to improve energy utilization rate of battery-powered electric vehicle (EV using brushless DC machine (BLDCM, the model of braking current generated by regenerative braking and control method are discussed. On the basis of the equivalent circuit of BLDCM during the generative braking period, the mathematic model of braking current is established. By using an extended state observer (ESO to observe actual braking current and the unknown disturbances of regenerative braking system, the autodisturbances rejection controller (ADRC for controlling the braking current is developed. Experimental results show that the proposed method gives better recovery efficiency and is robust to disturbances.

  17. Control strategy of disc braking systems for downward belt conveyors

    Institute of Scientific and Technical Information of China (English)

    Hou Youfu; Xie Fangwei; Huang Fei

    2011-01-01

    Reliability of braking systems is a key requirement to ensure the safety of in using downward belt conveyor brakes.By analyzing and comparing three commonly used braking velocity curves,we conclude that the Harrison curve is the best.Given the characteristics of a downward belt conveyor,we studied the control in a closed-loop velocity,a conventional PID method and an optimal PID control method.We used MATLAB/Simulink to simulate the three control methods.Our simulation results show that optimal PID control is especially suitable for disc braking systems.To verify the results from theoretical analysis and simulation,a multifunctional test-bed was developed to simulate the braking process of a disc brake system.Our experimental results demonstrate that the optimal PID control can make the output velocity to follow a preset velocity correctly with only small fluctuations,meeting the requirements of a flexible brake for a belt conveyor.

  18. Regenerative braking control strategy in mild hybrid electric vehicles equipped with automatic manual transmission

    Institute of Scientific and Technical Information of China (English)

    QIN Datong; YE Ming; LIU Zhenjun

    2007-01-01

    The actual regenerative braking force of an integrated starter/generator (ISG),which is varied with desired braking deceleration and vehicle speed,is calculated based on an analysis of the required deceleration,maximum braking force of ISG,engine braking force and state of charge (SOC) of battery.Braking force distribution strategies are presented according to the actual regenerative braking force of ISG.To recover the vehicle's kinetic energy maximally,braking shift rules for a mild hybrid electric vehicle (HEV) equipped with automatic manual transmission (AMT) are brought forward and effects of transmission ratios are considered.A test-bed is built up and regenerative braking tests are carried out.The results show that power recovered by the braking shift rules is more than that recovered by the normal braking control rules.

  19. iPad all-in-one for dummies

    CERN Document Server

    Muir, Nancy C

    2015-01-01

    For iPad users who want more information than the basics of the iPad,  iPad All-in-One For Dummies provides the goods! Based on Apple's new iOS software, which includes Siri for iPad, new and improved maps with turn by turn directions, shared photo streams, Facebook integration, Passbook, FaceTime video calls over cellular, new calling features such as instant text reply and callback reminders, improved email with a VIP inbox, iCloud browsing tabs, and much more. The book is organized into the following minibooks: iPad Basics - Covers basic functionality, synching with your computer and getti

  20. Bit-padding information guided channel hopping

    KAUST Repository

    Yang, Yuli

    2011-02-01

    In the context of multiple-input multiple-output (MIMO) communications, we propose a bit-padding information guided channel hopping (BP-IGCH) scheme which breaks the limitation that the number of transmit antennas has to be a power of two based on the IGCH concept. The proposed scheme prescribes different bit-lengths to be mapped onto the indices of the transmit antennas and then uses padding technique to avoid error propagation. Numerical results and comparisons, on both the capacity and the bit error rate performances, are provided and show the advantage of the proposed scheme. The BP-IGCH scheme not only offers lower complexity to realize the design flexibility, but also achieves better performance. © 2011 IEEE.

  1. Characterization of magnetic tunnel junction test pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Kjær, Daniel; Nielsen, Peter Folmer

    2015-01-01

    We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method...... on square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements...... as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment....

  2. MODIFICATION OF FLAKE REINFORCED FRICTION BRAKE COMPOSITE MATERIAL

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to the recent development trend and need of the friction brake material, the flake reinforced friction brake material has been made out by adjusting the recipe and techniques. The two-dimensional flake vermiculite is selected as the reinforced stuffing of the material; the modified resin is used as the basal bed of the material. The tests manifest that the properties of mechanics are high, the friction coefficients are suitable and stable,and especially in high temperatures the wear is low. It is an excellent friction brake material.

  3. A model of heat dissipation for MR based brake

    Energy Technology Data Exchange (ETDEWEB)

    Wiehe, A; Noack, V; Maas, J [Hochschule Ostwestfalen-Lippe - University of Applied Sciences, Control Engineering and Mechatronics, Liebigstrasse 87, D-32657 Lemgo (Germany)], E-mail: ansgar.wiehe@hs-owl.de

    2009-02-01

    In contrast to conventional brakes actuators based on magnetorheological fluids (MRF) offer an advantage in short term, peak load decelerating. The dissipation of a high amount of energy in a short period of time results in a thermal destruction of conventional brakes. Due to the volume based energy dissipation of MR actuators, instead of the surface based energy dissipation of conventional brakes, the rise of temperature and the distribution of energy shows significant advantages. In this paper a design rule for special peak load MR actuators is derived. Furthermore the simplified model, which is the basis of the design rule, is compared to several simulation models, with different levels of detail.

  4. STUDY KOMPARASI LOST FOAM DAN KONVENSIONAL CASTING PRODUK DISC BRAKE

    OpenAIRE

    Yoso, Sumeru; -, Suyitno

    2014-01-01

    Disc brake component is a vital component with gray cast iron base material, it’s also fast lasting wearing part, so it has be replaced often. The disc brake replacement component in a local market is being supplied by the small scale local metal casting industries have the same quality as the genuine part.Disc brake making process is utilizing casting method inserting RCS core between drag and coup, than metal molten poured inside mold. The problem of this method is the product result often ...

  5. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    OpenAIRE

    Jiankun Peng; Hongwen He; Wei Liu; Hongqiang Guo

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking s...

  6. Collagenous skeleton of the rat mystacial pad.

    Science.gov (United States)

    Haidarliu, Sebastian; Simony, Erez; Golomb, David; Ahissar, Ehud

    2011-05-01

    Anatomical and functional integrity of the rat mystacial pad (MP) is dependent on the intrinsic organization of its extracellular matrix. By using collagen autofluorescence, in the rat MP, we revealed a collagenous skeleton that interconnects whisker follicles, corium, and deep collagen layers. We suggest that this skeleton supports MP tissues, mediates force transmission from muscles to whiskers, facilitates whisker retraction after protraction, and limits MP extensibility.

  7. Interactive 3D display simulator for autostereoscopic smart pad

    Science.gov (United States)

    Choe, Yeong-Seon; Lee, Ho-Dong; Park, Min-Chul; Son, Jung-Young; Park, Gwi-Tae

    2012-06-01

    There is growing interest of displaying 3D images on a smart pad for entertainments and information services. Designing and realizing various types of 3D displays on the smart pad is not easy for costs and given time. Software simulation can be an alternative method to save and shorten the development. In this paper, we propose a 3D display simulator for autostereoscopic smart pad. It simulates light intensity of each view and crosstalk for smart pad display panels. Designers of 3D display for smart pad can interactively simulate many kinds of autostereoscopic displays interactively by changing parameters required for panel design. Crosstalk to reduce leakage of one eye's image into the image of the other eye, and light intensity for computing visual comfort zone are important factors in designing autostereoscopic display for smart pad. Interaction enables intuitive designs. This paper describes an interactive 3D display simulator for autostereoscopic smart pad.

  8. Tuning the Brake While Raising the Stake

    DEFF Research Database (Denmark)

    Meder, David; Haagensen, Brian Numelin; Hulme, Oliver

    2016-01-01

    to stop to bank the current balance. Within each gambling round, the accumulation of gains gradually increased reaction times for "continue" choices, indicating growing uncertainty in the decision to continue. Neural activity evoked by "continue" choices was associated with growing activity...... and connectivity of a cortico-subcortical "braking" network that positively scaled with the accumulated gains, including pre-supplementary motor area (pre-SMA), inferior frontal gyrus, caudate, and subthalamic nucleus (STN). The influence of the STN on continue-evoked activity in the pre-SMA was predicted...... a paradigm where subjects experienced increasing potential rewards coupled with increasing risk, this study addressed two unresolved questions in the field of decision-making: First, we investigated an "inhibitory" network of regions that has so far been investigated with externally cued action inhibition...

  9. Comparisonal Analysis of Manuevering and Braking

    Directory of Open Access Journals (Sweden)

    Artūras Žukas

    2011-04-01

    Full Text Available This article covers the possibility of avoiding a traffic accident considering a car driver who is fallen in a dangerous situation. In such a case, the driver can choose one of the following ways: hard braking or one of the types of maneuvering, including turning off, turning with straightening or changing a line regarding road surface type (dry asphalt, wet asphalt or snowy asphalt. The article also proposes formulas for calculating road distance the car travels till dead stop. Moreover, the tables display theoretical values taking into account various car speeds and road surfaces. The pictures help with determining the most suitable type of action in light of road and weather conditions as well as car speed. The pictures clearly show the dependence of road length on movement speed. At the end of the article, conclusions are proposed.Article in Lithuanian

  10. Linear Control Technique for Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    Chankit Jain

    2014-08-01

    Full Text Available Antilock braking systems are used in modern cars to prevent the wheels from locking after brakes are applied. The dynamics of the controller needed for antilock braking system depends on various factors. The vehicle model often is in nonlinear form. Controller needs to provide a controlled torque necessary to maintain optimum value of the wheel slip ratio. The slip ratio is represented in terms of vehicle speed and wheel rotation. In present work first of all system dynamic equations are explained and a slip ratio is expressed in terms of system variables namely vehicle linear velocity and angular velocity of the wheel. By applying a bias braking force system, response is obtained using Simulink models. Using the linear control strategies like PI-type the effectiveness of maintaining desired slip ratio is tested. It is always observed that a steady state error of 10% occurring in all the control system models.

  11. Evaluation strategy of regenerative braking energy for supercapacitor vehicle.

    Science.gov (United States)

    Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

    2015-03-01

    In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%.

  12. Numerical Modeling of Disc Brake System in Frictional Contact

    Directory of Open Access Journals (Sweden)

    A. Belhocine

    2014-03-01

    Full Text Available Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyse the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor by holding account certain parameters such as; the material used, the geometric design of the disc and the mode of braking. The analysis also gives us, the heat flux distribution for the two discs.

  13. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc, proposes an SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane mechanism to switch...

  14. Mathews Brake National Wildlife Refuge Public Use Development Plan - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for Mathews Brake NWR involves setting station public use goals, project a positive attitude, welcome and orient visitors, develop key resources awareness,...

  15. Handy Brake National Wildlife Refuge Habitat Management Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Handy Brake National Wildlife Refuge Habitat Management Plan provides a long-term vision and specific guidance on managing habitats for the resources of concern...

  16. Fishing Plan for Mathews Brake National Wildlife Refuge - 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal calls for the opening of Mathews Brake NWR to sport fishing. General regulations pertaining to licenses, creel limits, and methods of taking fish will...

  17. Fishery Management Plan for Mathews Brake National Wildlife Refuge - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U.S. Fish and Wildlife Service for Mathew's Brake National Wildlife Refuge. Data was provided by the refuge and area office...

  18. Fishery Management Plan for Morgan Brake National Wildlife Refuge - 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This management plan was prepared by the U. S. Fish and Wildlife Service for Morgan Brake National Wildlife Refuge. Data was provided by the Refuge and Area Office...

  19. Brake Pedal Displacement Measuring System based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Chang Wang

    2013-10-01

    Full Text Available Displacement of brake pedal was an important characteristic of driving behavior. This paper proposed a displacement measure algorithm based on machine vision. Image of brake pedal was captured by camera from left side, and images were processed in industry computer. Firstly, average smooth algorithm and wavelet transform algorithm were used to smooth the original image consecutively. Then, edge extracting method which combined Roberts’s operator with wavelet analysis was used to identify the edge of brake pedal. At last, least square method was adopted to recognize the characteristic line of brake pedal’s displacement. The experimental results demonstrated that the proposed method takes the advantages of Roberts’s operator and wavelet transform, it can obtain better measurement result as well as linear displacement sensors

  20. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    Directory of Open Access Journals (Sweden)

    A. Bessarab

    2013-01-01

    Full Text Available All over the world safety of maintained vehicles has the major value. For motor vehicles of the Republic of Belarus this problem is also actual. Maintenance of high reliability of brake systems of cars in operation is one of ways of the decision of a problem of increase of traffic safety.The analysis of reliability of brake systems of buses MAZ is carried out following the results of the state maintenance service in 2010 and the analysis of premature returns from routes of movement of buses MAZ-103 and МАZ-104 one of the motor transportation enterprises of a city of Minsk. Principal causes of structural parameters modification of brake pneumatic system of buses, the brake mechanism and elements АBS are considered.

  1. Crayfish survey at Morgan Brake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Crayfish sampling on Morgan Brake NWR for vernal crawfish and other species was done for 3 days at five sites. Data are present on species of crawfish and amphibians...

  2. Deployable Engine Air-Brake for Drag Management Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ATA Engineering, Inc., (ATA) proposes a Phase II SBIR program to demonstrate an innovative engine air-brake (EAB) technology that uses a deployable swirl vane...

  3. Morgan Brake National Wildlife Refuge Public Use Development Plan - 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This plan for Morgan Brake NWR involves setting station public use goals, project a positive attitude, welcome and orient visitors, develop key resources awareness,...

  4. AASPT Carbon/Carbon Aircraft Brake Disk Granted MPA

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    @@ Xi'an Chaoma Technology Co. Ltd. was issued Parts Manufacturer Approval (PMA) for Carbon/Carbon aircraft brake disk for Airbus 320 series by Civil Aviation Administration of China (CAAC). The company is held by Academy of Aerospace Solid Propulsion Technology (AASPT), a subsidiary of China Aerospace Science and Technology Corporation (CASC). It is the first approval given to a Chinese company to design and produce brakes for main civilian aircraft.

  5. FES-Assisted Walking with Spring Brake Orthosis: Simulation Studies

    OpenAIRE

    R. Jailani; Tokhi, M.O.; Gharooni, S. C.; B.S.K.K Ibrahim

    2011-01-01

    This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES) with spring brake orthosis (SBO). A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO...

  6. OPTIMAL EMERGENCY VEHICLE BRAKING CONTROL BASED ON DYNAMIC FRICTION MODEL

    Directory of Open Access Journals (Sweden)

    L. Olmos

    2005-04-01

    Full Text Available A dynamic friction model for the tire-road interface is used in an optimal control scheme for emergency braking ofvehicles. The controller sets a target relative velocity curve that the vehicle must track in order to achieve braking inminimum time. It is shown that this curve corresponds to the solution of a minimum time optimal control problem.The final goal of the control is to improve the safety levels in highway transportation.

  7. Brake subharmonic solutions of first order Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,we mainly use the Galerkin approximation method and the iteration inequalities of the L-Maslov type index theory to study the properties of brake subharmonic solutions for the first order non-autonomous Hamiltonian systems.We prove that when the positive integers j and k satisfy the certain conditions,there exists a jT-periodic nonconstant brake solution zj such that zj and zkj are distinct.

  8. Investigation of aerodynamic braking devices for wind turbine applications

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D.A. [R. Lynette & amp; Associates, Seattle, WA (United States)

    1997-04-01

    This report documents the selection and preliminary design of a new aerodynamic braking system for use on the stall-regulated AWT-26/27 wind turbines. The goal was to identify and design a configuration that offered improvements over the existing tip brake used by Advanced Wind Turbines, Inc. (AWT). Although the design objectives and approach of this report are specific to aerodynamic braking of AWT-26/27 turbines, many of the issues addressed in this work are applicable to a wider class of turbines. The performance trends and design choices presented in this report should be of general use to wind turbine designers who are considering alternative aerodynamic braking methods. A literature search was combined with preliminary work on device sizing, loads and mechanical design. Candidate configurations were assessed on their potential for benefits in the areas of cost, weight, aerodynamic noise, reliability and performance under icing conditions. As a result, two configurations were identified for further study: the {open_quotes}spoiler-flap{close_quotes} and the {open_quotes}flip-tip.{close_quotes} Wind tunnel experiments were conducted at Wichita State University to evaluate the performance of the candidate aerodynamic brakes on an airfoil section representative of the AWT-26/27 blades. The wind tunnel data were used to predict the braking effectiveness and deployment characteristics of the candidate devices for a wide range of design parameters. The evaluation was iterative, with mechanical design and structural analysis being conducted in parallel with the braking performance studies. The preliminary estimate of the spoiler-flap system cost was $150 less than the production AWT-26/27 tip vanes. This represents a reduction of approximately 5 % in the cost of the aerodynamic braking system. In view of the preliminary nature of the design, it would be prudent to plan for contingencies in both cost and weight.

  9. Reducing the leakage of body-worn incontinence pads.

    Science.gov (United States)

    Clancy, B; Malone-Lee, J

    1991-02-01

    The aim of this research was to evaluate the effect of various absorbent materials (fluff pulp and superabsorbent) on the leakage performance of incontinence pads. A shaped pad-and-pant system was used as the basic design and four pad types made to different specifications were compared using a double-blind technique. Forty-five elderly hospital residents who were incontinent of urine used all four pad types in a randomly allocated order. Data were recorded on more than 5000 pads over a 2-month period. Leakage was reduced by adding a second layer of fluff pulp and, whilst the addition of a superabsorbent material tended to reduce leakage further, we found no clear relationship between the amount of superabsorbent and the reduction of leakage. Other data indicated the importance of securing the pad in place with the appropriate net pants and the leakage rates of pads in relation to the amount of urine they contained. This research suggests that superabsorbent materials have great potential for reducing the leakage rate of incontinence pads but that the way in which they are incorporated into the pad, the amount of fluff pulp and the design of the pad also play an important part.

  10. Design and development of coil casing MRF brake system

    Directory of Open Access Journals (Sweden)

    Siti Lydia R.

    2017-01-01

    Full Text Available Nowadays magneto-rheological brakes has been introduce to overcome the drawback of conventional braking such as bulky, leakage and late build up pressure. Magnetic field is a main parameter need to be maximized in order to increase the efficiency of the brake. In MRF brake system the magnetic field directly affected by coil casing shapes. This paper focused on the study of the effect of coil casing shapes to the magnetic field distribution in MR brake. Finite Element Method will be used to analyze the magnetic field distribution produced by the coil. Five coils shape that different angle from 50° to 90° used in this study. As the result magnetic field was change quadratically by increasing the angle size. The best angle is between 60° to 70°. The peak value is at 70°. If more than that the magnetic field will drop. The significant of this study is to get the most efficient angle for the electromagnet casing for the MR brakes.

  11. Infrared characterization of thermal gradients on disc brakes

    Science.gov (United States)

    Panier, Stephane; Dufrenoy, Philippe; Bremond, Pierre

    2003-04-01

    The heat generated in frictional organs like brakes and clutches induces thermal distortions which may lead to localized contact areas and hot spots developments. Hot spots are high thermal gradients on the rubbing surface. They count among the most dangerous phenomena in frictional organs leading to damage, early failure and unacceptable braking performances such as brake fade or undesirable low frequency vibrations called hot judder. In this paper, an experimental study of hot spots occurrence in railway disc brakes is reported on. The aim of this study was to better classify and to explain the thermal gradients appearance on the surface of the disc. Thermograph measurements with an infrared camera have been carried out on the rubbing surface of brake discs on a full-scale test bench. The infrared system was set to take temperature readings in snap shot mode precisely synchronized with the rotation of the disc. Very short integration time allows reducing drastically haziness of thermal images. Based on thermographs, a classification of hot-spots observed in disc brakes is proposed. A detailed investigation of the most damaging thermal gradients, called macroscopic hot spots (MHS) is given. From these experimental researches, a scenario of hot spots occurrence is suggested step by step. Thanks to infrared measurements at high frequency with high resolution, observations give new highlights on the conditions of hot spots appearance. Comparison of the experimental observations with the theoretical approaches is finally discussed.

  12. Development of automobile brake lining using pulverized cow hooves

    Directory of Open Access Journals (Sweden)

    Katsina C. BALA

    2016-06-01

    Full Text Available Asbestos has been used for so long as automobile brake lining material because of its good physical and chemical properties. However, due to the health hazard associated with its handling, it has lost favour and several alternative materials are being increasingly used. Asbestos-free brake lining was developed in this work using pulverized cow hooves along with epoxy resin, barium sulphate, graphite and aluminium oxide. This was with a view to exploiting the characteristics of cow hooves, which are largely discarded as waste materials to replace asbestos which has been found to be carcinogenic. Samples of brake linings were produced using compressive moulding in which the physical and mechanical properties of the samples were studied. The results obtained showed that proper bonding was achieved as the percentage by weight of epoxy resin increased and percentage by weight of pulverized cow hooves decreased. The hardness, compressive strength, coefficient of friction, water and oil absorption, relative density and wear rate of the brake linings were determined and compared with existing brake lining properties. The result indicates that pulverized cow hooves can be used as brake lining material for automobiles.

  13. RESEARCH ON AUTOMOTIVE BRAKE DISCS OF SiCP/Al COMPOSITE%SiC颗粒增强铝基复合材料制动盘的研究

    Institute of Scientific and Technical Information of China (English)

    齐海波; 丁占来; 樊云昌; 姜稚清

    2001-01-01

    采用半固态搅拌熔炼-液态模锻工艺制备了与Santana轿车前制动器相匹配的SiC颗粒增强铝基复合材料制动盘,对该制动盘进行了材料拉伸性能和微观结构分析,并在SCHENCK制动试验台上进行了制动性能和制动磨损试验。结果表明,复合材料的拉伸性能优于传统制动盘材料HT250铸铁;在各种制动工况条件下,复合材料制动盘对制动衬片的摩擦系数均在大众公司企业标准规定的范围之内,且较稳定;此外,复合材料制动盘质轻、耐磨,制动噪音小、温升低,运转平稳;因此,可望以其替代传统的铸铁制动盘,提高制动器的安全可靠性和服役寿命,减轻轿车悬挂系统的重量,降低油耗。%The SiCP/Al composite brake disc designed for the front brake of SANTANA cars was prepared by semi-solid stirring melting and liquid forging. The tensile properties and microstructures of the disc materials were examined, and the tribological-wear performances of the disc were tested on the SCHENCK brake testing system made in Germany. The results show that the tensile properties of the composites are superior to those of the conventional disc material, grey cast iron; and that under different braking conditions, the friction coefficients of the composite disc against the conventional brake pad are within the range specified by the standard of VOLKSWAGEN company and with small fluctuations. It is also found that the brake disc made of the composite has such advantages as light weight, high wear resistance, low braking noise and low braking temperature rises, smooth operating, etc. Hence, it is hopeful to substitute the composite disc for the traditional cast iron disc to increase reliability and to prolong the survice life of the car brake, to lighten the weight of the hanging system, and thus, to decrease gas expenditure of cars.

  14. Sistem Pendingin Paksa Anti Panas Lebih (Over Heating pada Rem Cakram (Disk Brake Kendaraan

    Directory of Open Access Journals (Sweden)

    Joni Dewanto

    2010-01-01

    Full Text Available Until now, the vehicle brakes are not usually equipped with a special cooling system, so that the release of heat into the air occurs naturally. When used continuously, the brakes can suffer damage as a result of the occurrence of over-heating. This condition is potentially causing a fatal accident. Physically, the over-heating often occurs in type disc brake, because the heat transfer surface is less proportionately, especially for high braking loads. This research aims to develop a brake disc with an active cooling system to prevent overheating. The system is applied to a simulated model of disc brakes empirically. The test was conducted at several levels of constant disc speed and breaking force. The results of this research indicate that at various braking load, the development of disc brakes with an active cooling system in the form of water vapor that is sprayed, can control the brake temperature rise and prevent over-heating.

  15. Regenerative Braking Algorithm for an ISG HEV Based on Regenerative Torque Optimization

    Institute of Scientific and Technical Information of China (English)

    XIAO Wen-yong; WANG Feng; ZHUO Bin

    2008-01-01

    A novel regenerative braking algorithm based on regenerative torque optimization with emulate engine compression braking (EECB) was proposed to make effective and maximum use of brake energy in order to improve fuel economy. The actual brake oil pressure of driving wheel which is reduced by the amount of the regenerative braking force is supplied from the electronic hydraulic brake system. Regenerative torque optimization maximizes the actual regenerative power recuperation by energy storage component, and EECB is a useful extended type of regenerative braking. The simulation results show that actual regenerative power recuperation for the novel regenerative braking algorithm is more than using conventional one, and life-span of brake disks is prolonged for the novel algorithm.

  16. Metal pad instabilities in liquid metal batteries

    CERN Document Server

    Zikanov, Oleg

    2015-01-01

    A mechanical analogy is used to analyze the interaction between the magnetic field, electric current and deformation of interfaces in liquid metal batteries. It is found that, during charging or discharging, a sufficiently large battery is prone to instabilities of two types. One is similar to the metal pad instability known for aluminum reduction cells. Another type is new. It is related to the destabilizing effect of the Lorentz force formed by the azimuthal magnetic field induced by the base current and the current perturbations caused by the local variations of the thickness of the electrolyte layer.

  17. Determining Compatibilities of Reactive Dyes in Pad Dyeing

    Institute of Scientific and Technical Information of China (English)

    屠天民

    2001-01-01

    Compatibilities of reactive dyes were conventionally shown by exhausting curves. But the change of proportion of dyes in padding dyebath was difficult for pad dyeing to be described by these curves. In this paper, a kind of simulation of pad dyeing process was used to determine dyestuff compatibility in pad dyeing for ramie and linen fabrics. Seven reactive dyes were divided into three groups and tested., The group with Cibacron Yellow C - 2R, Red C - R, and Blue C - R showed very good compatibility both for ramie and linen,and the other two groups of dyes gave out correspondingly low compatibilities in the pad dyeing tests. The results of the method for determining the compatibility of dyes displayed good consistency with the actul pad dyeing process.

  18. Take control of media on your iPad

    CERN Document Server

    Carlson, Jeff

    2011-01-01

    Join media-savvy author Jeff Carlson as he helps you enjoy media on your iPad like never before. Jeff explains basic and advanced ways of adding media to your iPad, and gives you a thorough grounding in Apple's core media apps-iBooks, iPod, Videos, and Photos. He also helps you integrate your iPad with an Apple TV and looks at various ways of using an iPad as a TV remote. You'll also get plenty of suggestions for third-party apps and products, whether you want to read books not available in the iBookstore, stream music from the Internet to your iPad, convert your own DVD library to iPad-frien

  19. PadSteg: Introducing Inter-Protocol Steganography

    CERN Document Server

    Jankowski, Bartosz; Szczypiorski, Krzysztof

    2011-01-01

    Hiding information in network traffic may lead to leakage of confidential information. In this paper we introduce a new steganographic system: the PadSteg (Padding Steganography). To authors' best knowledge it is the first information hiding solution which represents inter-protocol steganography i.e. usage of relation between two or more protocols from the TCP/IP stack to enable secret communication. PadSteg utilizes ARP and TCP protocols together with an Etherleak vulnerability (improper Ethernet frame padding) to facilitate secret communication for hidden groups in LANs (Local Area Networks). Basing on real network traces we confirm that PadSteg is feasible in today's networks and we estimate what steganographic bandwidth is achievable while limiting the chance of disclosure. We also point at possible countermeasures against PadSteg.

  20. iPad all-in-one for dummies

    CERN Document Server

    Muir, Nancy C

    2012-01-01

    Six minibooks in one show you how to power-use the iPad For work, play, and life on the road, the iPad has quickly become indispensable, and the new iPad is packed with even more features and power than ever. In this fun and practical guide, long-time For Dummies author Nancy C. Muir walks you through the latest functions, features, and capabilities of the iPad. Get up to speed on the basics, see how to use your iPad to get more organized and productive, learn to use your iPad for work, and discover all the ways to have fun. This book covers it all, and in full color! Packs six minibooks in on

  1. Electro-mechanical Braking Method in Hybrid Electric Vehicles Based on Feedback Control Theory

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YU Jun-quan; LIU Zheng-yu; CHANG Cheng

    2014-01-01

    In this paper, the hybrid electric vehicle braking process is researched, by using variables consists of HEV speed, motor speed, and state of charge established, functions of mechanical braking force, regenerative braking force and efficiency of energy recovery are constructed, and the control goal is to maximization the energy recovery efficiency. Under the feedback control strategy, with the constrain condition of braking strength and braking stability, combining experiments in ADVISOR, in different experiments of different working conditions, we can see that in UDDS Cycle, the regenerative braking efficiency is the best. What’s more, compared with strategies in ADVISOR, strategy proposed in this paper is obviously better.

  2. An integrated control strategy for the composite braking system of an electric vehicle with independently driven axles

    Science.gov (United States)

    Sun, Fengchun; Liu, Wei; He, Hongwen; Guo, Hongqiang

    2016-08-01

    For an electric vehicle with independently driven axles, an integrated braking control strategy was proposed to coordinate the regenerative braking and the hydraulic braking. The integrated strategy includes three modes, namely the hybrid composite mode, the parallel composite mode and the pure hydraulic mode. For the hybrid composite mode and the parallel composite mode, the coefficients of distributing the braking force between the hydraulic braking and the two motors' regenerative braking were optimised offline, and the response surfaces related to the driving state parameters were established. Meanwhile, the six-sigma method was applied to deal with the uncertainty problems for reliability. Additionally, the pure hydraulic mode is activated to ensure the braking safety and stability when the predictive failure of the response surfaces occurs. Experimental results under given braking conditions showed that the braking requirements could be well met with high braking stability and energy regeneration rate, and the reliability of the braking strategy was guaranteed on general braking conditions.

  3. Foot-pad dermatitis in broilers and turkeys

    OpenAIRE

    Berg, Charlotte C.

    1998-01-01

    Foot-pad dermatitis is a condition characterised by lesions on the ventral foot-pads of poultry. It is a type of contact dermatitis, which in an early stage results in hyperkeratosis, erosions and discoloration of the skin. The erosions can develop into ulcers. In severe cases, the foot-pad lesions may cause pain which together with a deteriorated state of health constitutes a welfare issue. It has also been indicated that broilers with severe foot-pad dermatitis show slower weight gain. The ...

  4. Intelligently Controllable Walker with Magnetorheological Fluid Brake

    Science.gov (United States)

    Kikuchi, Takehito; Tanida, Sosuke; Tanaka, Toshimasa; Kobayashi, Keigo; Mitobe, Kazuhisa

    Caster walkers are supporting frames with casters and wheels. These tools are regularly utilized as life support tools or walking rehabilitation tools in hospitals, nursing homes and individual residences. Users of the walkers can easily move it thanks to its wheels and casters. However falling accidents often happen when it moves without users. The falling accident is very serious problem and one of leading causes of secondary injuries. In the other case, it is hard to move to desired directions if users have imbalance in their motor functions or sensory functions, e.g., hemiplegic patients. To improve safeness and operability of the walkers, we installed compact MR fluid brakes on the wheels and controlled walking speed and direction of the walker. We named this intelligently controllable walker, “i-Walker” and discussed on the control methods and experimental results in this paper. Preliminary trials for direction control of the first-generation of the i-Walker (i-Walker1) are presented. On the basis of the results, we improved the control method and hardware of the i-Walker1, and developed the second-generation (i-Walker2). System description and experimental results of the i-Walker2 are also described. The i-Walker2 has better operability and lower energy consumption than that of the i-Walker1. The line-tracing controller of the i-Walker2 well controls human motions during walking experiments on the target straight line.

  5. Flow braking and the substorm current wedge

    Science.gov (United States)

    Birn, J.; Hesse, M.; Haerendel, G.; Baumjohann, W.; Shiokawa, K.

    1999-09-01

    Recent models of magnetotail activity have associated the braking of earthward flow with dipolarization and the reduction and diversion of cross-tail current, that is, the signatures of the substorm current wedge. Estimates of the magnitude of the diverted current by Haerendel [1992] and Shiokawa et al. [1997, 1998] tend to be lower than results from computer simulations of magnetotail reconnection and tail collapse [Birn and Hesse, 1996], despite similar underlying models. An analysis of the differences between these estimates on the basis of the simulations gives a more refined picture of the diversion of perpendicular into parallel currents. The inertial currents considered by Haerendel [1992] and Shiokawa et al. [1997] contribute to the initial current reduction and diversion, but the dominant and more permanent contribution stems from the pressure gradient terms, which change in connection with the field collapse and distortion. The major effect results from pressure gradients in the z direction, rather than from the azimuthal gradients [Shiokawa et al., 1998], combined with changes in By and Bx. The reduction of the current density near the equatorial plane is associated with a reduction of the curvature drift which overcompensates changes of the magnetization current and of the gradient B drift current. In contrast to the inertial current effects, the pressure gradient effects persist even after the burst of earthward flow ends.

  6. The Analysis of Ttransient Temperature Field Distribution of Vehicle Ventilated Disc Brake under Emergency Braking Condition%紧急制动工况下汽车通风盘式制动器瞬态温度场分布的研究

    Institute of Scientific and Technical Information of China (English)

    简弃非; 吴昊

    2016-01-01

    The ventilated disc brake which used in a passenger vehicle front wheel as the research object is set,its thermal-structure coupled three-dimensional finite element analysis model is set up. Then direct coupling method is adopt to simulate the transient temperature field of ventilated disc brake under emergency braking condition on the basis of model,eventually the distribution and change characteristics of temperature field of ventilated brake disc and pad in emergency braking are gotten. The results show that the temperature field distribution of brake disc is not axial symmetry in emergency braking,there are certain temperature gradient in radial,circumferential and axial three directions. The highest temperature of the brake disc appeared in 1. 91 s,the highest temperature is 227. 1℃. Meanwhile the ventilated disc brake bench test is carried on under the brake condition as same as the simulation a-nalysis,the obtained experimental result basic consistent with the result of the simulation calculation,thus the validi-ty of the simulation analysis is verified,and a theoretical basis for design and optimization of ventilated disc brake is provided.%以某乘用车前轮采用的通风盘式制动器为研究对象,建立其热-结构耦合的3维有限元分析模型.在此基础上采用直接耦合法对该通风盘式制动器在紧急制动工况下的瞬态温度场进行仿真分析,获得整个通风式制动盘和摩擦片在紧急制动过程中温度场的分布情况及变化特性.结果显示:在整个紧急制动过程中,制动盘温度场的分布不是轴对称的,其在径向、周向及轴向3个方向上均存在着一定的温度梯度;制动盘的最高温度出现在1.91 s,最高温度为227.1℃.同时对该通风盘式制动器进行了与仿真分析相同制动工况下的台架试验,所获得的实验结果与仿真计算结果基本一致,从而验证了仿真分析的有效性,为通风盘式制动器的设计及优化提供了理论基础.

  7. Gecko adhesion pad: a smart surface?

    Science.gov (United States)

    Pesika, Noshir S.; Zeng, Hongbo; Kristiansen, Kai; Zhao, Boxin; Tian, Yu; Autumn, Kellar; Israelachvili, Jacob

    2009-11-01

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  8. Gecko adhesion pad: a smart surface?

    Energy Technology Data Exchange (ETDEWEB)

    Pesika, Noshir S [Chemical and Biomolecular Engineering Department, Tulane University, New Orleans, LA 70118 (United States); Zeng Hongbo [Chemical and Materials Engineering Department, University of Alberta, Edmonton, AB, T6G 2V4 (Canada); Kristiansen, Kai; Israelachvili, Jacob [Chemical Engineering Department, University of California, Santa Barbara, CA 93117 (United States); Zhao, Boxin [Chemical Engineering Department and Waterloo Institute of Nanotechnology, University of Waterloo, Ontario, N2L 3G1 (Canada); Tian Yu [State Key Laboratory of Tribology, Department of Precision Instruments, Tsinghua University, Beijing 100084 (China); Autumn, Kellar, E-mail: npesika@tulane.ed [Department of Biology, Lewis and Clark College, Portland, OR 97219 (United States)

    2009-11-18

    Recently, it has been shown that humidity can increase the adhesion of the spatula pads that form the outermost (adhesive) surface of the tokay gecko feet by 50% relative to the main adhesion mechanism (i.e. van der Waals adhesive forces), although the mechanism by which the enhancement is realized is still not well understood. A change in the surface hydrophobicity of a gecko setal array is observed when the array, which supports the spatulae, is exposed to a water drop for more than 20 min, suggesting a change in the hydrophilic-lyophilic balance (HLB), and therefore of the conformation of the surface proteins. A surface force apparatus (SFA) was used to quantify these changes, i.e. in the adhesion and friction forces, while shearing the setal array against a silica surface under (i) dry conditions, (ii) 100% humidity and (iii) when fully immersed in water. The adhesion increased in the humid environment but greatly diminished in water. Although the adhesion forces changed significantly, the friction forces remained unaffected, indicating that the friction between these highly textured surfaces is 'load-controlled' rather than 'adhesion-controlled'. These results demonstrate that the gecko adhesive pads have the ability to exploit environmental conditions to maximize their adhesion and stabilize their friction forces. Future designs of synthetic dry adhesives inspired by the gecko can potentially include similar 'smart' surfaces that adapt to their environment.

  9. PENGARUH PENGELUARAN PEMERINTAH TERHADAP PDRB DAN PAD

    Directory of Open Access Journals (Sweden)

    Harry A. P. Sitaniapessy

    2013-04-01

    Full Text Available Abstrak: Pengaruh Pengeluaran Pemerintah Terhadap PDRB dan PAD. Penelitian ini bertujuan untuk menentukan  pengaruh pengeluaran pemerintah terhadap Produk Domestik Regional Bruto dan Pendapatan Asli Daerah Kabupaten Maluku Tengah periode 2005-2011. Penelitian ini lebih difokuskan pada tiga sektor utama yaitu sektor pengeluaran pemerintah yaitu sektor pertanian, perikanan serta perindustrian dan perdagangan karena ketiga sektor tersebut memiliki pengeluaran yang lebih besar dibanding sektor – sektor lain. Untuk menganalisis data, penelitian ini menggunakan analisis regresi sederhana dan regresi berganda. Pengujian dilakukan dengan menggunakan regresi berganda dan regresi sederhana untuk empat hipotesis yang diujikan. Hasil penelitian menunjukkan bahwa keempat hipotesis yang diajukan dalam penelitian ini terdukung.   Kata Kunci:    Pengeluaran Pemerintah, Produk Domestik Regional Bruto, Pendapatan Asli Daerah.   Abstract: Government Expenditure Influence on Gross Regional Domestic Product and Regional Income. This study aims to determine the impact of government expenditure towards GRDP and PAD of Kabupaten Maluku Tengah in period 2003-2011. This study are focused to three majors of government expenditure ;  agriculture,  fishery, industry and commerce, because they have larger expenditure than the others. The analysis of the data were conducted using simple regression analysis and multiple regression. Testing was done using multiple regression and simple regression for the four hypotheses tested. The result shows that the four hypotheses proposed in this study is supported.   Keywords:    government expenditure, gross regional domestic product, regional income

  10. Launch Pad 39 Hail Monitor Array System

    Science.gov (United States)

    2008-01-01

    Weather conditions at Kennedy Space Center are extremely dynamic, and they greatly affect the safety of the Space Shuttles sitting on the launch pads. For example, on May 13, 1999, the foam on the External Tank (ET) of STS-96 was significantly damaged by hail at the launch pad, requiring rollback to the Vehicle Assembly Building. The loss of ET foam on STS-114 in 2005 intensified interest in monitoring and measuring damage to ET foam, especially from hail. But hail can be difficult to detect and monitor because it is often localized and obscured by heavy rain. Furthermore, the hot Florida climate usually melts the hail even before the rainfall subsides. In response, the hail monitor array (HMA) system, a joint effort of the Applied Physics Laboratory operated by NASA and ASRC Aerospace at KSC, was deployed for operational testing in the fall of 2006. Volunteers from the Community Collaborative Rain, Hail, and Snow (CoCoRaHS) network, in conjunction with Colorado State University, continue to test duplicate hail monitor systems deployed in the high plains of Colorado.

  11. Infrapatellar fat pad haemangioma: Case report

    Directory of Open Access Journals (Sweden)

    Dzoleva-Tolevska Roza

    2014-07-01

    Full Text Available We present a case of a 38-year-old woman with a soft tissue mass on the right knee in medial infrapatellar area. The flexion of the knee appeared to be limited and a pain was present at maximal flexion. Ultrasonography, standard X-ray and CT scan were performed for diagnosis of this soft tissue tumour. MRI was not done due to technical problems. Anyhow the MRI could provide us with more presumptions of the type of the tumour, but it will not affect the surgeon's decision for operation. Anyway the final diagnosis will come out of the histopatological findings. Arthroscopic examination was performed in order to eliminate possible problems into the joint followed by open wide excision. A soft tissue tumour with dimensions of 5 x 4 x 1.5 cm was excised. Histopathological diagnosis was synovial haemangioma located in the infrapatellar fat pad. The patient was asymptomatic postoperatively. Haemangiomas located in infrapatellar fat pad are rare. Orthopaedic surgeons can often be confused by more common entities like chondromallatia of patella, synovitis of the knee, Hoffa's disease, other soft tissue tumours, even lesion of meniscus. So, accurate diagnosis is very important for differentiation. Operative excision, arthroscopic or open wide, is definitive treatment for this benign tumour.

  12. Piecewise polynomial chaos expansion with an application to brake squeal of a linear brake system

    Science.gov (United States)

    Sarrouy, E.; Dessombz, O.; Sinou, J.-J.

    2013-02-01

    This paper proposes numerical developments based on polynomial chaos (PC) expansions to process stochastic eigenvalue problems efficiently. These developments are applied to the problem of linear stability calculations for a simplified brake system: the stability of a finite element model of a brake is investigated when its friction coefficient or the contact stiffness are modeled as random parameters. Getting rid of the statistical point of view of the PC method but keeping the principle of a polynomial decomposition of eigenvalues and eigenvectors, the stochastic space is decomposed into several elements to realize a low degree piecewise polynomial approximation of these quantities. An approach relying on continuation principles is compared to the classical dichotomy method to build the partition. Moreover, a criterion for testing accuracy of the decomposition over each cell of the partition without requiring evaluation of exact eigenmodes is proposed and implemented. Several random distributions are tested, including a uniform-like law for description of friction coefficient variation. Results are compared to Monte Carlo simulations so as to determine the method accuracy and efficiency. Some general rules relative to the influence of the friction coefficient or the contact stiffness are also inferred from these calculations.

  13. Unusual Braking Indices in Young X-ray Pulsars

    Science.gov (United States)

    Frederic Archibald, Robert; Kaspi, Victoria M.; Beardmore, Andrew P.; Gehrels, Neil; Kennea, Jamie; Gotthelf, Eric V.; Ferdman, Robert; Guillot, Sebastien; Harrison, Fiona; Keane, Evan; Pivovaroff, Michael; Stern, Daniel; Tendulkar, Shriharsh P.; Tomsick, John

    2016-04-01

    Pulsars spin down over time. By measuring braking indices of pulsars, effectively the change in the spin-down rate over time, we can probe the underlying driving engine of the spin-down. For a magnetic dipole in a vacuum, n is predicted to be 3. To date, all measured braking indices are less than 3, which can be explained, e.g. by particle winds, changes in the magnetic field. In all models of braking indices, n should be nearly constant on year time-scales. Here, I will discuss two recent observation results that challenge this model, interestingly both coming from young X-ray pulsars with no detected radio emission. The first, a long-lived decrease in the braking index of PSR J1846-0258 following a burst of magnetar-like activity, and secondly, the first stationary braking index greater than three. Understanding neutron-star spin evolution is key to constraining these objects' long-term energy output and has relevance to topics ranging from pulsar wind nebulae and supernova remnants to core-collapse supernova rates, physics, and expected outcomes.

  14. Hall drift and the braking indices of young pulsars

    CERN Document Server

    Gourgouliatos, K N

    2014-01-01

    Braking index measurements of young radio pulsars are all smaller than the value expected for spin down by magnetic dipole braking. We investigate magnetic field evolution in the neutron star crust due to Hall drift as an explanation for observed braking indices. Using numerical simulations and a semi-analytic model, we show that a $\\approx 10^{14}\\ {\\rm G}$ quadrupolar toroidal field in the neutron star crust at birth leads to growth of the dipole moment at a rate large enough to agree with measured braking indices. A key factor is the density at which the crust yields to magnetic stresses that build up during the evolution, which sets a characteristic minimum Hall timescale. The observed braking indices of pulsars with inferred dipole fields of $\\lesssim 10^{13}\\ {\\rm G}$ can be explained in this picture, although with a significant octupole component needed in some cases. For the stronger field pulsars, those with $B_d\\gtrsim 10^{13}\\ {\\rm G}$, we find that the magnetic stresses in the crust exceed the max...

  15. Prosthetic leg powered by MR brake and SMA wires

    Science.gov (United States)

    Nguyen, The; Munguia, Vicente; Calderon, Jose

    2014-04-01

    Current knee designs for prosthetic legs rely on electric motors for both moving and stationary states. The electric motors draw an especially high level of current to sustain a fixed position. The advantage of using magnetorheological (MR) fluid is that it requires less current and can have a variable braking torque. Besides, the proposed prosthetic leg is actuated by NiTinol wire, a popular shape memory alloy (SMA). The incorporation of NiTinol gives the leg more realistic weight distribution with appropriate arrangement of the batteries and wires. The prosthesis in this research was designed with MR brake as stopping component and SMA wire network as actuating component at the knee. The MR brake was designed with novel non-circular shape for the rotor that improved the braking torque while minimizing the power consumption. The design also helped simplify the control of braking process. The SMA wire network was design so that the knee motion was actively rotated in both directions. The SMA wires were arranged and played very similar role as the leg's muscles. The study started with the overall solid design of the knee including both MR and SMA parts. Theoretical models were derived and programmed in Simulink for both components. The simulation was capable of predicting the power required for moving the leg or hold it in a fixed position for a certain amount of time. Subsequently, the design was prototyped and tested to validate the theoretical prediction. The theoretical models were updated accordingly to correlate with the experimental data.

  16. Charging valve of the full hydraulic braking system

    Directory of Open Access Journals (Sweden)

    Jinshi Chen

    2016-03-01

    Full Text Available It is known that the full hydraulic braking system has excellent braking performance. As the key component of the full hydraulic braking system, the parameters of the accumulator charging valve have a significant effect on the braking performance. In this article, the key parameters of the charging valve are analyzed through the static theoretical and an Advanced Modeling Environment for performing Simulation of engineering systems (AMESim simulation model of the dual-circuit accumulator charging valve is established based on the real structure parameters first. Second, according to the results of the dynamic simulation, the dynamic characteristics of the charging pressure, the flow rate, and the frequency of the charging valve are studied. The key parameters affecting the serial production are proposed and some technical advices for improving the performance of the full hydraulic system are provided. Finally, the theoretical analysis is validated by the simulation results. The comparison between the simulation results and the experimental results indicates that the simulated AMESim model of the charging valve is accurate and credible with the error rate inside 0.5% compared with the experimental result. Hence, the performance of the charging valve meets the request of the full hydraulic braking system exactly.

  17. Freshwater Fish Survey of Mathews Brake Water Body - 1980 and 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Freshwater Fish Survey of Mathews Brake water body including land not within Mathews Brake NWR. Methods included Electroshocker, creel census, and seine.

  18. Maslov-type index and brake orbits in nonlinear Hamiltonian systems

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we study the Maslov-type index theory for linear Hamiltonian systems with brake orbits boundary value conditions and its applications to the existence of multiple brake orbits of nonlinear Hamiltonian systems.

  19. 77 FR 46633 - Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits

    Science.gov (United States)

    2012-08-06

    ... RIN 2126-AB28 Parts and Accessories Necessary for Safe Operation: Brakes; Adjustment Limits AGENCY... Safety Administration (FMCSA) amends the requirements regarding brake readjustment limits in the Federal Motor Carrier Safety Regulations (FMCSRs). This rule amends the readjustment limits, clarifies...

  20. Implementing iPads in the Inclusive Classroom Setting

    Science.gov (United States)

    Maich, Kimberly; Hall, Carmen

    2016-01-01

    This column provides practical suggestions to help guide teachers in utilizing classroom sets of iPads. Following a brief introduction to tablet technology in inclusive classrooms and the origin of these recommendations from a case study focus group, important elements of setting up classroom iPad use, from finding funding to teaching apps, are…

  1. Choosing and using disposable body-worn continence pads.

    Science.gov (United States)

    Gilbert, Rachel

    Disposable, body-worn pads are the product most commonly chosen to contain and absorb urine and faeces (Pomfret, 2000). The cost to the NHS of supplying continence pads has been estimated at 80 million pounds per annum (Euromonitor, 1999) and is a huge financial burden on local services.

  2. Control and sensor techniques for PAD servo motor drive

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Zhang, Zhe; Andersen, Michael A. E.;

    2015-01-01

    The Piezoelectric Actuator Drive (PAD) is a new type of electrical motor that employs piezoelectric multilayer actuators coupled with a form-fitted micro-mechanical gearing to generate rotary motion. The PAD is precise, having a positioning error of less than 2 arc-seconds. Its typical output...

  3. Modelling of LEG tilting pad journal bearings with active lubrication

    DEFF Research Database (Denmark)

    Cerda Varela, Alejandro Javier; García, Asier Bengoechea; Santos, Ilmar

    2017-01-01

    This work constitutes the first step in a research effort aimed at studying the feasibility of introducing an active lubrication concept in tilting pad journal bearings (TPJBs) that feature the leading edge groove (LEG) lubrication system. The modification of the oil flow into each pad supply...

  4. EL device pad-printed on a curved surface

    Science.gov (United States)

    Lee, Taik-Min; Hur, Shin; Kim, Jae-Hyun; Choi, Hyun-Cheol

    2010-01-01

    This paper is unique in that the electro-luminescence (EL) display device is fabricated on a curved surface using the pad-printing method. The precision of the pad-printing process is explored to verify whether it can be used for micro patterning. The minimum pattern size and pattern distortion, which is caused by use of the pad, were tested and simulated. The minimal pattern was found to be 35 µm wide and 2.4 µm thick. Pattern distortion when pad-printing on a flat surface, caused by the deformation of the silicon pad, was less than 5 µm. Numerical analysis shows how to estimate pattern distortion when pad-printing on a curved surface. The proposed EL display device consists of five layers, namely a bottom electrode, dielectric layer, phosphor, transparent electrode and a bus electrode. The ink of each layer was reformulated with solvents and the pad-printing conditions were controlled. A PEN film was used first in order to realize the pad-printing process condition of each layer. Finally, the EL display device was printed onto a dish with a radius of curvature of 80 mm. The luminance was 180 cd m-2.

  5. iPads in Inclusive Classrooms: Ecologies of Learning

    Science.gov (United States)

    Meyer, Bente

    2013-01-01

    This paper builds on data from a project where iPads were used in a lower secondary school in Denmark to support school development and inclusive learning environments. The paper explores how iPads enter into and work as part of an ecology of learning in five classes in lower secondary school. The paper argues that we should disengage approaches…

  6. iPad Use and Student Engagement in the Classroom

    Science.gov (United States)

    Mango, Oraib

    2015-01-01

    iPads and handheld digital devices have been securing their place in educational institutions surrounded by debates between advocates and skeptics. In light of not enough evidence supporting the use of iPads in education, this study examined the ways that college students in two foreign language classrooms perceived the influence of the use of…

  7. 21 CFR 872.3540 - OTC denture cushion or pad.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a...-counter. (b) Classification. (1) Class I if the device is made of wax-impregnated cotton cloth that the... denture cushion or pad is made of a material other than wax-impregnated cotton cloth or if the...

  8. Control and sensor techniques for PAD servo motor drive

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Zhang, Zhe; Andersen, Michael A. E.;

    2015-01-01

    The Piezoelectric Actuator Drive (PAD) is a new type of electrical motor that employs piezoelectric multilayer actuators coupled with a form-fitted micro-mechanical gearing to generate rotary motion. The PAD is precise, having a positioning error of less than 2 arc-seconds. Its typical output tor...

  9. Patient-centred Prevention among PAD Patients

    DEFF Research Database (Denmark)

    Pii, Kathrine Hoffmann

    2014-01-01

    Intro: This paper discusses a central professional dilemma in patient-centred education: on one hand the concern for ensuring patients autonomy and right to make their own decisions regarding their treatment and, on the other hand, a concern for getting patients to make the “right” decisions......-centredness is thus promoted as a way to organize health more effectively (in terms of cost and treatment outcomes) and as a way to ensure patients’ autonomy and fundamental right to make their own decisions regarding their treatment. Critical voices within social and nursing theory have however argued...... of a patient-centred prevention programme aimed at PAD patients, which includes medical treatment as well as individual nurse-led lifestyle-oriented conversations (inspired by psychological theory and methods such as Motivational Interviewing). Method: The findings are based on four months ethnographic field...

  10. Learning through telepresence with iPads

    DEFF Research Database (Denmark)

    Meyer, Bente Tobiesen

    2015-01-01

    This study aims to present findings from an ongoing study in three rural schools in Denmark where videoconferences are used as part of the teaching at lower secondary level. The research focuses on how students learn from videoconferences that are both one-to-many and peer-to-peer. Videoconferenc......This study aims to present findings from an ongoing study in three rural schools in Denmark where videoconferences are used as part of the teaching at lower secondary level. The research focuses on how students learn from videoconferences that are both one-to-many and peer......-to-peer. Videoconferencing, conceptualized by the schools in question as telepresence, is performed in a unique combination of desktop interaction through mobile devices (iPads) and studio-based large screen lectures and interaction....

  11. Metal pad instabilities in liquid metal batteries

    Science.gov (United States)

    Zikanov, Oleg

    2016-11-01

    Strong variations between the electrical conductivities of electrolyte and metal layers in a liquid metal battery indicate the possibility of 'metal pad' instabilities. Deformations of the electrolyte-metal interfaces cause strong perturbations of electric currents, which, hypothetically, can generate Lorentz forces enhancing the deformations. We investigate this possibility using two models: a mechanical analogy and a two-dimensional linearized approximation. It is found that the battery is prone to instabilities of two types. One is similar to the sloshing-wave instability observed in the Hall-Héroult aluminum reduction cells. Another is new and related to the interactions of current perturbations with the azimuthal magnetic field induced by the base current. Financial support was provided by the U.S. National Science Foundation (Grant CBET 1435269).

  12. Launch Pad Flame Trench Refractory Materials

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Parlier, Christopher R.; Bucherl, Cori; Sampson, Jeffrey W.; Curran, Jerome P.; Kolody, Mark; Perusich, Steve; Whitten, Mary

    2010-01-01

    The launch complexes at NASA's John F. Kennedy Space Center (KSC) are critical support facilities for the successful launch of space-based vehicles. These facilities include a flame trench that bisects the pad at ground level. This trench includes a flame deflector system that consists of an inverted, V-shaped steel structure covered with a high temperature concrete material five inches thick that extends across the center of the flame trench. One side of the "V11 receives and deflects the flames from the orbiter main engines; the opposite side deflects the flames from the solid rocket boosters. There are also two movable deflectors at the top of the trench to provide additional protection to shuttle hardware from the solid rocket booster flames. These facilities are over 40 years old and are experiencing constant deterioration from launch heat/blast effects and environmental exposure. The refractory material currently used in launch pad flame deflectors has become susceptible to failure, resulting in large sections of the material breaking away from the steel base structure and creating high-speed projectiles during launch. These projectiles jeopardize the safety of the launch complex, crew, and vehicle. Post launch inspections have revealed that the number and frequency of repairs, as well as the area and size of the damage, is increasing with the number of launches. The Space Shuttle Program has accepted the extensive ground processing costs for post launch repair of damaged areas and investigations of future launch related failures for the remainder of the program. There currently are no long term solutions available for Constellation Program ground operations to address the poor performance and subsequent failures of the refractory materials. Over the last three years, significant liberation of refractory material in the flame trench and fire bricks along the adjacent trench walls following Space Shuttle launches have resulted in extensive investigations of

  13. Pad printer for electronics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This is the Final report on DARPA-sponsored development Program Pad Printer for Electronics DE-FC04-95AL87486 which was initiated in February, 1995 and intended to run 24 months to February 1997. The Program has significant value to the Thick Film processing industry, an electronic manufacturing alternative for producing functional modules integrated at the multichip level. The result is highly reliable, high volumetric efficiency, subassemblies for military applications and for commercial applications in severe environments, such as automotive, portable communications, and bio-implantable devices. The program progressed quite satisfactorily through 19 months, when it encountered severe, non-technical, difficulties. Resolving these difficulties resulted in several months of delay in completing the Program, but resulted in only a trivial increase in total program cost and no increase in cost to the sponsor. The principle Objective of the Program was the development of a printing system -- machine and appropriate inks -- compatible with existing thick-film processing but offering a 5x improvement in line density. This objective has been met. The Pad Printer is capable of printing suitable inks in traces 25 g wide on 50g centers to a fired thickness of 3 {mu}; each of these parameters is roughly 1/5 the value of the current alternative, silk-screen printing. The available inks represent an assortment of conductor, dielectric, and insulator formulations and the knowledge developed permits extending this family of inks to new and diverse functional materials. An important secondary objective was maximum compatibility with existing Thick Film processing; the printer and ink systems may be substituted directly for the silk screen printers in existing processes. The Program reached or exceeded its other Technical Objectives in almost every case and, in those few instances where the objective was only partially met, work continues under private funding.

  14. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  15. Thermal Modeling of Disc Brake Rotor in Frictional Contact

    Science.gov (United States)

    Ali, Belhocine; Ghazaly, Nouby Mahdi

    2013-01-01

    Safety aspect in automotive engineering has been considered as a number one priority in development of new vehicle. Each single system has been studied and developed in order to meet safety requirement. Instead of having air bag, good suspension systems, good handling and safe cornering, there is one most critical system in the vehicle which is brake systems. The objective of this work is to investigate and analyze the temperature distribution of rotor disc during braking operation using ANSYS Multiphysics. The work uses the finite element analysis techniques to predict the temperature distribution on the full and ventilated brake disc and to identify the critical temperature of the rotor. The analysis also gives us, the heat flux distribution for the two discs.

  16. Braking the Gas in the beta Pictoris Disk

    CERN Document Server

    Fern'andez, R; Wu, Y; Brandeker, Alexis; Fern\\'andez, Rodrigo

    2006-01-01

    (Abridged) The main sequence star beta Pictoris hosts the best studied circumstellar disk to date. Nonetheless, a long-standing puzzle has been around since the detection of metallic gas in the disk: radiation pressure from the star should blow the gas away, yet the observed motion is consistent with Keplerian rotation. In this work we search for braking mechanisms that can resolve this discrepancy. We find that all species affected by radiation force are heavily ionized and dynamically coupled into a single fluid by Coulomb collisions, reducing the radiation force on species feeling the strongest acceleration. For a gas of solar composition, the resulting total radiation force still exceeds gravity, while a gas of enhanced carbon abundance could be self-braking. We also explore two other braking agents: collisions with dust grains and neutral gas. Grains surrounding beta Pic are photoelectrically charged to a positive electrostatic potential. If a significant fraction of the grains are carbonaceous (10% in t...

  17. Braking Performance of a Biomimetic Squid-Like Underwater Robot

    Institute of Scientific and Technical Information of China (English)

    Md.Mahbubar Rahman; Sinpei Sugimori; Hiroshi Miki; Risa Yamamoto; Yugo Sanada; Yasuyuki Toda

    2013-01-01

    In this study,the braking performance of the undulating fin propulsion system ofa biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model.The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results.Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage.The stopping performance of the undulating fin propulsion system tured out to be excellent considering the short stopping time and short stopping distance.This is because of the large negative thrust produced by progressive wave in opposite direction.It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.

  18. Stability Control of Vehicle Emergency Braking with Tire Blowout

    Directory of Open Access Journals (Sweden)

    Qingzhang Chen

    2014-01-01

    Full Text Available For the stability control and slowing down the vehicle to a safe speed after tire failure, an emergency automatic braking system with independent intellectual property is developed. After the system has received a signal of tire blowout, the automatic braking mode of the vehicle is determined according to the position of the failure tire and the motion state of vehicle, and a control strategy for resisting tire blowout additional yaw torque and deceleration is designed to slow down vehicle to a safe speed in an expected trajectory. The simulating test system is also designed, and the testing results show that the vehicle can be quickly stabilized and kept in the original track after tire blowout with the emergency braking system described in the paper.

  19. Dynamics Models of Interacting Torques of Hydrodynamic Retarder Braking Process

    Directory of Open Access Journals (Sweden)

    Wenhao Shen

    2013-01-01

    Full Text Available Hydrodynamic retarder is a kind of assist braking device, which can transfer the vehicle kinetic energy into the heat energy of working medium. There are complicated three-dimensional viscous incompressible turbulent flows in hydrodynamic retarder, so that it is difficult to represent the parameters changing phenomenon and investigate the interactional law. In order to develop a kind of reliable theoretical model for internal flow field, in this study, the dynamics models of interacting torques between impellers and working fluid were constructed based on braking energy transfer principle by using Euler theory to describe the flow state in view of time scale. The model can truly represent the dynamic braking process.

  20. Taking Your iPad 2 to the Max

    CERN Document Server

    Sadun, Erica; Sande, Steve

    2011-01-01

    iPad 2: It looks different. It acts different. It connects to the world, yet it is as personal as a well-worn book. And now it has two cameras!. Taking Your iPad 2 to the Max is written so that anyone can quickly get up to speed on Apple's latest hit. As bloggers at The Unofficial Apple Weblog (TUAW.com), the authors have the happy privilege of working with Apple products every day, and they'll guide you through all of the perks of being an iPad 2 owner. This book takes you from selecting and buying an iPad, to connecting it to the Internet, to using the incredible power of the iPad and all it

  1. Incontinence pads: clinical performance, design and technical properties.

    Science.gov (United States)

    Cottenden, A M

    1988-11-01

    The paper describes the functional requirements of urinary incontinence pads and reviews the results of several studies which seek to relate the clinical performance of pads to their design and the technical properties of their constituent materials. Pad designs covered include: simple rectangular (for use with conventional pants or marsupial pants containing a pouch); wing-folded; shaped; and all-in-one infant-style diapers. Data on the clinical and technical properties of fluff wood pulp and hydrogel absorbents, and viscose rayon, polyester, polypropylene and polyethylene coverstocks are presented. Attention is focussed on four major aspects of pad function: freedom from leakage; freedom from discomfort and skin damage; ease of application and removal; and aesthetic properties. The relationships established between clinical and technical data will be of interest to health care professionals selecting products; organizations seeking to create standards; and pad designers.

  2. Beginning iPad Development for iPhone Developers Mastering the iPad SDK

    CERN Document Server

    Wooldridge, Dave; Mark, D

    2010-01-01

    It's in magazines and newspapers, it's on television and radio, it's on busses and billboards and pretty much everywhere you look (except for Apple stores, where it's likely still sold out). The iPad is the hot new touchscreen tablet from Apple, representing the next generation of mobile computing.Packed with dozens of new features, the iOS 3.2 SDK enables you to build sophisticated, desktop-quality apps for this exciting new platform. Every iPhone and iPod touch app developer looking to take the next step and move into the iPad arena will want to read this book from cover to cover. Beginning

  3. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Jiankun Peng

    2015-01-01

    Full Text Available This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved.

  4. Hierarchical Control Strategy for the Cooperative Braking System of Electric Vehicle

    Science.gov (United States)

    Peng, Jiankun; He, Hongwen; Liu, Wei; Guo, Hongqiang

    2015-01-01

    This paper provides a hierarchical control strategy for cooperative braking system of an electric vehicle with separated driven axles. Two layers are defined: the top layer is used to optimize the braking stability based on two sliding mode control strategies, namely, the interaxle control mode and signal-axle control strategies; the interaxle control strategy generates the ideal braking force distribution in general braking condition, and the single-axle control strategy can ensure braking safety in emergency braking condition; the bottom layer is used to maximize the regenerative braking energy recovery efficiency with a reallocated braking torque strategy; the reallocated braking torque strategy can recovery braking energy as much as possible in the premise of meeting battery charging power. The simulation results show that the proposed hierarchical control strategy is reasonable and can adapt to different typical road surfaces and load cases; the vehicle braking stability and safety can be guaranteed; furthermore, the regenerative braking energy recovery efficiency can be improved. PMID:26236772

  5. Investigation of Product Performance of Al-Metal Matrix Composites Brake Disc using Finite Element Analysis

    Science.gov (United States)

    Fatchurrohman, N.; Marini, C. D.; Suraya, S.; Iqbal, AKM Asif

    2016-02-01

    The increasing demand of fuel efficiency and light weight components in automobile sectors have led to the development of advanced material parts with improved performance. A specific class of MMCs which has gained a lot of attention due to its potential is aluminium metal matrix composites (Al-MMCs). Product performance investigation of Al- MMCs is presented in this article, where an Al-MMCs brake disc is analyzed using finite element analysis. The objective is to identify the potentiality of replacing the conventional iron brake disc with Al-MMCs brake disc. The simulation results suggested that the MMCs brake disc provided better thermal and mechanical performance as compared to the conventional cast iron brake disc. Although, the Al-MMCs brake disc dissipated higher maximum temperature compared to cast iron brake disc's maximum temperature. The Al-MMCs brake disc showed a well distributed temperature than the cast iron brake disc. The high temperature developed at the ring of the disc and heat was dissipated in circumferential direction. Moreover, better thermal dissipation and conduction at brake disc rotor surface played a major influence on the stress. As a comparison, the maximum stress and strain of Al-MMCs brake disc was lower than that induced on the cast iron brake disc.

  6. 49 CFR 232.207 - Class IA brake tests-1,000-mile inspection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Class IA brake tests-1,000-mile inspection. 232... Class IA brake tests—1,000-mile inspection. (a) Except as provided in § 232.213, each train shall receive a Class IA brake test performed by a qualified person, as defined in § 232.5, at a location...

  7. 49 CFR 238.15 - Movement of passenger equipment with power brake defects.

    Science.gov (United States)

    2010-10-01

    ... cutting out of secondary brake systems; (B) Inoperative or otherwise defective handbrakes or parking... 49 Transportation 4 2010-10-01 2010-10-01 false Movement of passenger equipment with power brake... § 238.15 Movement of passenger equipment with power brake defects. Beginning on January 1, 2002,...

  8. 75 FR 5553 - Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids

    Science.gov (United States)

    2010-02-03

    ... Federal Motor Vehicle Safety Standards; Motor Vehicle Brake Fluids AGENCY: National Highway Traffic Safety... NPRM proposes to amend FMVSS No. 116, Motor Vehicle Brake Fluids, so that brake fluids would be tested... Date VII. Rulemaking Analyses and Notices VIII. Public Participation I. Background Federal...

  9. 49 CFR 214.529 - In-service failure of primary braking system.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false In-service failure of primary braking system. 214... Maintenance Machines and Hi-Rail Vehicles § 214.529 In-service failure of primary braking system. (a) In the event of a total in-service failure of its primary braking system, an on-track roadway...

  10. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-01-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in…

  11. 77 FR 51649 - Federal Motor Vehicle Safety Standards; Motorcycle Brake Systems

    Science.gov (United States)

    2012-08-24

    .... George Soodoo, Division Chief, Vehicle Dynamics (NVS-122), Office of Crash Avoidance Standards (Email... technologies would help prevent the introduction of unsafe motorcycle brake systems on the road. Moreover... the proper grade of brake fluid. If the service brake system is a split hydraulic type, a...

  12. Stability analysis of automotive disc brake system with random parameters%随机参数汽车盘式制动器的稳定性分析

    Institute of Scientific and Technical Information of China (English)

    吕辉; 于德介

    2014-01-01

    针对不确定性参数汽车制动器噪声的抑制问题,基于随机参数分析理论,将响应面法与有限元复特征值技术相结合,提出了一种随机参数汽车制动器系统稳定性的分析方法。该方法用随机参数对制动器系统的不确定性进行描述,系统的摩擦系数、制动压力、制动盘厚度、制动片厚度和支撑背板的厚度参数分别采用随机变量表示;为提高分析效率,建立了包含随机变量的制动器不稳定特征值的响应面近似模型,进而根据系统特征值的随机特性对系统稳定性进行分析。用该方法对某车的浮钳盘式制动器系统进行研究,采用蒙特卡洛方法分析了随机参数正态分布假设下系统特征值的概率统计特性和参数灵敏度。结果表明:通过修改制动器支撑背板的厚度以提高支撑刚度,可有效改善制动器系统的稳定性,减小制动噪声的产生。%To suppress the brake noises of an automotive disc brake system with uncertain parameters ,a stability analysis method of automotive brake systems is presented in this paper .The essential idea of this method is to combine the RSM (Re-sponse Surface Method) and complex eigenvalue analysis techniques with random parameters introduced to describe such uncer-tainties in the brake system as friction coefficients ,brake pressure ,disc thickness ,pad thickness and backplate thickness .In order to improve the analysis efficiency ,RSM is used to build up the approximation models to express the functional relation-ships between the unstable eigenvalues and the system parameters ,which makes it available to study the stability of the brake system according to the random characteristics of the unstable eigenvalues .The stability analysis of a float caliper disc brake system is carried out by the proposed method with the random parameters assumed to follow normal distributions .The statisti-cal characteristics and the sensitivities

  13. EFFECT OF GENDER DIFFERENCE ON BRAKE REACTION TIME

    Directory of Open Access Journals (Sweden)

    Ashok

    2016-02-01

    Full Text Available BACKGROUND OF THE STUDY Reaction time is the time taken to respond to a stimulus or change in the environment. It is a method to assess the time taken from the perception of a stimulus followed by mental processing for a motor response. Reaction time in various day to day activities as in driving a car is very important. Brake reaction time (BRT is the time taken for the driver to respond to visualize an object and to press the brake pedal. It is affected by many features like age, gender, neuromuscular disorders. OBJECTIVE OF THE STUDY Study has been undertaken to compare the BRT in male and female drivers and to analyze the effect of sex difference on Brake reaction time. MATERIALS & METHODS Male and female subjects between the age group of 25 – 35 years with driving license were included. Study is conducted in a stationary car. An in-house built; braking timer is fixed to the electric circuit of the braking system in the car. This device is wirelessly connected to the reaction time software installed in the laptop. The subject is instructed to press the brake pedal when the light changed from red to green in the laptop screen. 5 readings are taken and the mean BRT is recorded. STATISTICAL ANALYSIS & RESULTS Statistical analysis done with unpaired student t test indicates that the BRT was more in the females than the males and was statistically significant (p value - 0007. CONCLUSION Gender difference has a significant effect on BRT and reaction time in female is longer than for the males.

  14. RELIABILITY OF BRAKE SYSTEMS OF BUSES OF GROUP MAZ

    OpenAIRE

    A. Bessarab

    2013-01-01

    All over the world safety of maintained vehicles has the major value. For motor vehicles of the Republic of Belarus this problem is also actual. Maintenance of high reliability of brake systems of cars in operation is one of ways of the decision of a problem of increase of traffic safety.The analysis of reliability of brake systems of buses MAZ is carried out following the results of the state maintenance service in 2010 and the analysis of premature returns from routes of movement of buses M...

  15. Effect of comfort pads and incubator design on neonatal radiography

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xia; Baad, Michael; Reiser, Ingrid; Feinstein, Kate A.; Lu, Zhengfeng [University of Chicago Medicine, Department of Radiology, Chicago, IL (United States)

    2016-01-15

    There has been increasing interest in patient dose reduction in neonatal intensive care units. Removing comfort pads for radiography has been identified as a potential means to decrease patient dose. To assess the effect of comfort pads and support trays on detector entrance exposure (DEE) and image quality for neonatal radiography, and its implication for patient dose. Comfort pads and support trays from three incubator and warmer systems were examined. The attenuation of the primary beam by these structures was measured using a narrow beam geometry. Their effect on DEE and image quality was then assessed using typical neonatal chest radiography techniques with three configurations: (1) both the comfort pad and support included in the beam, (2) only the support tray included and (3) both the comfort pad and support tray removed. Comfort pads and support trays were found to attenuate the primary beam by 6-15%. Eliminating these structures from the X-ray beam's path was found to increase the detector entrance exposure by 28-36% and increase contrast-to-noise ratio by more than 21%, suggesting room for patient dose reduction when the same image quality is maintained. Comfort pads and tray support devices can have a considerable effect on DEE and image quality, with large variations among different incubator designs. Positioning the image detector directly underneath neonatal patients for radiography is a potential means for patient dose reduction. However, such benefit should be weighed against the risks of moving the patient. (orig.)

  16. Failure analysis of energy storage spring in automobile composite brake chamber

    Science.gov (United States)

    Luo, Zai; Wei, Qing; Hu, Xiaofeng

    2015-02-01

    This paper set energy storage spring of parking brake cavity, part of automobile composite brake chamber, as the research object. And constructed the fault tree model of energy storage spring which caused parking brake failure based on the fault tree analysis method. Next, the parking brake failure model of energy storage spring was established by analyzing the working principle of composite brake chamber. Finally, the data of working load and the push rod stroke measured by comprehensive test-bed valve was used to validate the failure model above. The experimental result shows that the failure model can distinguish whether the energy storage spring is faulted.

  17. Asynchronous Electric Motor with Built-in Combined Braking Device Based on Electro-Mechanical Brake and Electro-Magnetic Clutch

    OpenAIRE

    V. V. Solenkov; Brel, V. V.

    2011-01-01

    The paper shows advantages and disadvantages of the known designs of asynchronous motors with electro-mechanical braking device. A new developed and studied asynchronous motor design with built-in combined braking device based on an electro-mechanical brake and an electro-magnetic clutch is given in the paper. The paper describes its advantages and prospects of its usage for electric drives operating in intermittent cycle.

  18. Design of Braking Caliper's Braking Torque in Hydraulic Disc Braking System%液压盘式刹车系统制动钳制动力矩的设计

    Institute of Scientific and Technical Information of China (English)

    高燕; 宋胜涛; 王跃军; 韩美香; 郭太清

    2012-01-01

    针对目前液压盘式刹车系统刹车力矩小,刹车性能不稳定等现状,基于老算法对制动转矩的计算原理设计了一种新算法,对制动钳的工作制动转矩,紧急制动转矩及驻车制动转矩,冗余安全设计等进行了计算.为提高液压盘式刹车系统的设计效率和安全系数,该算法从制动钳的工作原理出发,通过对制动钳的制动结构进行分析,以下放到井中的最重套管柱所形成的静制动转矩作为盘刹系统能满足的最小工作制动转矩为依据,通过验证计算结果,保障了液压盘式刹车系统的安全性和有效性.%The current braking torque of the hydraulic disc braking system is small and braking performance is instable.A new algorithm was designed based on the braking torque's calculation of the old algorithm.The work braking torque, emergency braking torque, park braking torque and the redundant safety design were calculated in this new algorithm.To improve the design efficiency and safety coefficient of the hydraulic disc braking system, the algorithm based on the working principle of the braking caliper, through the braking structure analysis of the braking caliper, according to the static braking torque formed by the heaviest casing string that put into the well could be taken as the minimum working braking torque which the disc braking system could meet.The safety and effectiveness of the hydraulic disc braking system are safeguarded through the authentication and calculation of the result.

  19. Coaxial magnetic brakes using single-domain YBCO

    Energy Technology Data Exchange (ETDEWEB)

    Putman, P.T. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)], E-mail: pputman@uh.edu; Salama, K. [Texas Center for Superconductivity and Department of Mechanical Engineering, University of Houston, Houston, TX 77204 (United States)

    2008-06-15

    In coaxial magnetic brakes, the changing field produced by movement of a solenoidal magnet induces a current in the wall of a conductive tube. The interaction of the field and current leads to a repulsive force that slows the motion of the magnet. For brake applications that require high force density, melt-textured YBCO is a clear choice of material for the magnet because it can carry high currents at a given field and temperature, and is inherently capable of operating in persistent current mode. We present calculations of the performance of this type of brake as a function of magnet current density for catch tubes composed of aluminum and titanium. These results are validated with low speed (20 m/s) tests. Calculations indicate that melt-textured magnets can decelerate projectiles with a mass of 1 kg from 2000 m/s to rest in distances on the order of 10 m. This suggests that this type of brake is suitable for use in hypervelocity experiments, which sometimes requires nondestructive deceleration of projectiles for diagnostic purposes.

  20. 49 CFR 571.106 - Standard No. 106; Brake hoses.

    Science.gov (United States)

    2010-10-01

    ... identifiable stripes of at least one-sixteenth of an inch in width, placed on opposite sides of the brake hose... a twisted orientation in either side of the vehicle, need not meet the requirements of S5.2.1. S5.2... assemblies with end fittings that do not permit entry of the gauge (e.g., restrictive orifice or...

  1. ANALYSIS OF FAILURE MECHANISM IN MULTIPLE DISC WET BRAKES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    By the numberical calculation of dynamic lining pressure distributions,temperature fields and thermal stress fields of steel plates,a method using nonlinear finite element techniques to analyze failure mechanism of a multiple disc wet brake is detailed ,and some measures for combatting these failures are provided.

  2. CFD Analysis of Automotive Ventilated Disc Brake Rotor

    Directory of Open Access Journals (Sweden)

    Amol V. More

    2014-04-01

    Full Text Available Disc brakes work on the principle of friction by converting kinetic energy into heat energy. The key objective of a disc brake rotor is to accumulate this heat energy and dissipate it immediately. The effect of rotational speed on the aero-thermal performance is assessed. The rotor speed is observed to have substantial effect on the rotor performance. The heat dissipation and thermal performance of ventilated brake discs intensely be influenced by the aerodynamic characteristics of the air flow through the rotor passages. In order to investigate the aero-thermal performance of the ventilated disc brake at several altered driving speeds of the vehicle, the simulations were carried out at 3 different rotational speeds of 44rad/s 88 rad/s and 120 rad/s. The semi-automatic geometric model is created using the package Solid Works and the mesh for the model is done using ICEM CFD and the Post processing of the results is done using FLUENT-14.5.The results are discussed and presented in detail.

  3. 49 CFR 238.315 - Class IA brake test.

    Science.gov (United States)

    2010-10-01

    ... first morning departure of each commuter or short-distance intercity passenger train, unless all of the... repeated at the first passenger terminal if the train remains on a source of compressed air and: (1) The... that utilize an electric signal to communicate a service brake application and only a pneumatic...

  4. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.;

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coil...

  5. Can dark matter explain the braking index of neutron stars?

    DEFF Research Database (Denmark)

    Kouvaris, C.; Perez-Garcia, M. A.

    2014-01-01

    We explore a new mechanism of slowing down the rotation of neutron stars via accretion of millicharged dark matter. We find that this mechanism yields pulsar braking indices that can be substantially smaller than the standard n similar to 3 of the magnetic dipole radiation model for millicharged...... dark matter particles that are not excluded by existing experimental constraints thus accommodating existing observations....

  6. Chinese Enterprises Slams the Brakes on Acquisition of Overseas Mines

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On June 25,China Mining Association revealed that,as of the middle of June,Chinese enterprises slammed the brakes on acquisition of overseas mines.There are only 53 overseas mine acquisition cases so far this year,

  7. iPad mini测评手记

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    正如世人预料的那样,苹果推出了小号版的iPad。它被称为iPad Mini——这一点也不意外。我的两位同事Jason Snell和Dan Moren出席了苹果的发布会,有机会得以在第一时间试用iPad mini。下面是我们及同事在使用iPad Mini后的初步印象。

  8. Accurate micro Hall effect measurements on scribe line pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Wang, Fei;

    2009-01-01

    Hall mobility and sheet carrier density are important parameters to monitor in advanced semiconductor production. If micro Hall effect measurements are done on small pads in scribe lines, these parameters may be measured without using valuable test wafers. We report how Hall mobility can...... be extracted from micro four-point measurements performed on a rectangular pad. The dimension of the investigated pad is 400 × 430 ¿m2, and the probe pitches range from 20 ¿m to 50 ¿m. The Monte Carlo method is used to find the optimal way to perform the Hall measurement and extract Hall mobility most...

  9. Diagnostic accuracy of heel pad palpation - A phantom study

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Matteoli, Sara; Wilhjelm, Jens E.;

    2008-01-01

    Falanga torture involves repetitive blunt trauma to the soles of the feet and typically leaves few detectable changes. Reduced elasticity in the heel pads has been reported as characteristic sequelae and palpatory testing of heel pad elasticity is therefore part of medicolegal assessment of alleged...... torture victims. The goal was to test the accuracy of two experienced investigators in determining whether a heel pad model was soft, medium or hard. The skin-to-bone distance in the models varied within the human range....

  10. Peptidomimetics as protein arginine deiminase 4 (PAD4) inhibitors.

    Science.gov (United States)

    Trabocchi, Andrea; Pala, Nicolino; Krimmelbein, Ilga; Menchi, Gloria; Guarna, Antonio; Sechi, Mario; Dreker, Tobias; Scozzafava, Andrea; Supuran, Claudiu T; Carta, Fabrizio

    2015-06-01

    The protein arginine deiminase 4 (PAD4) is a calcium-dependent enzyme, which catalyses the irreversible conversion of peptidyl-arginines into peptidyl-citrullines and plays an important role in several diseases such as in the rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, Creutzfeldt-Jacob's disease and cancer. In this study, we report the inhibition profiles and computational docking toward the PAD4 enzyme of a series of 1,2,3-triazole peptidomimetic-based derivatives incorporating the β-phenylalanine and guanidine scaffolds. Several effective, low micromolar PAD4 inhibitors are reported in this study.

  11. Teach yourself visually the new iPad

    CERN Document Server

    Watson, Lonzell

    2012-01-01

    A new edition of a bestseller, fully updated on the latest features of the iPad! The evolution of the iPad continues to deliver amazing possibilities, which is exactly why this bestselling guide evolves right along with it! Fully updated with coverage on the latest generation of the iPad, this full-color, step-by-step guide is perfectly suited for anyone who is a visual learner and learns best by visual cues and a tactile interface. You'll learn to access and download books, apps, music, and video content as well as send photos and emails, sync with other devices and services, and confidently

  12. Correcting Students' Misconceptions about Automobile Braking Distances and Video Analysis Using Interactive Program Tracker

    Science.gov (United States)

    Hockicko, Peter; Trpišová, Beáta; Ondruš, Ján

    2014-12-01

    The present paper informs about an analysis of students' conceptions about car braking distances and also presents one of the novel methods of learning: an interactive computer program Tracker that we used to analyse the process of braking of a car. The analysis of the students' conceptions about car braking distances consisted in obtaining their estimates of these quantities before and after watching a video recording of a car braking from various initial speeds to a complete stop and subsequent application of mathematical statistics to the obtained sets of students' answers. The results revealed that the difference between the value of the car braking distance estimated before watching the video and the real value of this distance was not caused by a random error but by a systematic error which was due to the incorrect students' conceptions about the car braking process. Watching the video significantly improved the students' estimates of the car braking distance, and we show that in this case, the difference between the estimated value and the real value of the car braking distance was due only to a random error, i.e. the students' conceptions about the car braking process were corrected. Some of the students subsequently performed video analysis of the braking processes of cars of various brands and under various conditions by means of Tracker that gave them exact knowledge of the physical quantities, which characterize a motor vehicle braking. Interviewing some of these students brought very positive reactions to this novel method of learning.

  13. A mechanical brake hardware-in-the-loop simulation of a railway vehicle that accounts for hysteresis and pneumatic cylinder dynamics

    OpenAIRE

    Dong-Chan Lee; Chul-Goo Kang

    2015-01-01

    A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installat...

  14. Design and testing of a rotational brake with shear thickening fluids

    Science.gov (United States)

    Tian, Tongfei; Nakano, Masami

    2017-03-01

    A rotational brake working with shear thickening fluid (STF) was designed and tested in this study. With the optimisation in design, most of the STF in the brake can receive the same shear rate when the brake rotates. The parts of this brake were fabricated with a 3D printer and then assembled manually. Three types of STFs with various carrier fluids and different particles were fabricated and tested with a rheometer. Then the brake with each STF was separately tested with the rheometer. The estimated and measured torques as a function of the angular velocity fit each other well. The stability of the rotational STF brake was investigated in repeated tests, which proved the function of the brake for a long time.

  15. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    Directory of Open Access Journals (Sweden)

    Fei Gao

    2014-01-01

    Full Text Available The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc radial direction was caused by severe friction in short time and the low heat transfer coefficient of its material. Parametric analysis for disc brakes have been carried out by comparison of grouped brake applications conform to UIC code, the main factor cause the high temperature gradient and thermal stress of brake disc is brake force and its initial speed.

  16. A low cost, light weight cenosphere–aluminium composite for brake disc application

    Indian Academy of Sciences (India)

    V Saravanan; P R Thyla; S R Balakrishnan

    2016-02-01

    The commonly used composite material for brake rotor consists of silicon carbide (SiC) or aluminium oxide (Al$_2$O$_3$) particles which are more expensive. The weight of conventionally used composite is more compared to base alloy. The aim of this paper is to develop a light weight material for brake disc applications thereby substituting base alloy and conventional composite. This analysis led to 10 vol% cenosphere reinforced aluminium alloy (AA) 6063 composite as the most appropriate material for brake disc. To ensure the manufacturability of composite, composite brake rotor was casted using the sand casting technique and was machined to achieve the final component. Thermal capability of brake disc was ensured by studying temperature variation through vehicle testing procedure of disc brake. Cost reduction is one of the important benefit acquired using cenosphere reinforced composite. This was ensured by cost estimation and analysis. The cost estimated to manufacture the AA6063 brake disc was compared with composite cost.

  17. Synthesis and Characterization of Antifriction Magnetorheological Fluids for Brake

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2013-07-01

    Full Text Available Magnetorheological (MR fluids are smart materials with shear strength ranging between zero to 100 kPa under the influence of magnetic field. The present paper discusses the synthesis of MR fluid and its application in brake. In MR brake, gap between stator and rotor is filled with low (off-state viscosity MR fluid. On the application of magnetic field, MR fluid changes its state from liquid to semi-solid by aligning magnetic particles in chains. Due to such chaining action, yield strength of fluid increases, friction between stator and rotor increases and fulfils the braking function. The strength of magnetic particle is a function of relative speed between stator and rotor, applied magnetic field, and volume percentage of magnetic particle. In this study antifriction (off-state and strong chain (on-state CI based MR fluid has been prepared by mixing oleic acid as antifriction additives and tetramethylammonium hydroxide as surfactant to reduce the agglomeration of the MR fluid. Yield strengths of the synthesized MR fluid in on-state and off-state have been compared with commercially available MRF 241ES fluid. A flywheel based MR brake experimental setup has been developed to analyze the performance of designed and developed MR brake.Results show that synthesized MR fluid is stronger and faster in response compared to MRF 241ES fluid.Defence Science Journal, 2013, 63(4, pp.408-412, DOI:http://dx.doi.org/10.14429/dsj.63.2633

  18. Pericruciate fat pad of the knee: anatomy and pericruciate fat pad inflammation: cadaveric and clinical study emphasizing MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Skaf, Abdalla Youssef [Hospital do Coracao (HCor), Department of Radiology, Sao Paulo, SP (Brazil); Hernandez Filho, Guinel [Santa Casa de Sao Paulo Hospital, Department of Radiology, Sao Paulo, SP (Brazil); Dirim, Berna [Izmir Atatuerk Training and Research Hospital, Department of Radiology, Karsiyaka, izmir (Turkey); Wangwinyuvirat, Mani [Rajavithi Hospital, Department of Radiology, Bangkok (Thailand); Trudell, Debra; Resnick, Donald [University of California, San Diego, Department of Radiology, Veterans Affairs Medical Center, La Jolla, CA (United States); Haghigi, Parvitz [University of California, San Diego, Department of Pathology, Veterans Affairs Medical Center, La Jolla, CA (United States)

    2012-12-15

    The pericruciate fat pad is located in the intercondylar fossa, intimate with the cruciate ligaments. With MR imaging, signal abnormality of the pericruciate fat pad has been observed in patients with posterior knee pain. The purpose of this study was to describe the anatomy of the pericruciate fat pad in cadaveric specimens and to document the clinical spectrum of pericruciate fat pad inflammation. Twelve cadaveric knees underwent MR imaging with T1 and T2 multiplanar images. Cadaveric sections were then prepared for macroscopic evaluation, with additional histologic analysis performed in four cases. MR images in seventeen patients (ten males, seven females; average age, 31.5 years; age range, 19-57 years) involved in intensive sporting activity and with posterior knee pain were reviewed. MR images in cadaveric specimens showed a fat pad that was located above and between the cruciate ligaments, near their attachment sites in the inner portion of the femoral condyles, within the intercondylar fossa. Fatty tissue covered by a thin layer of synovial membrane was confirmed at histology. Seventeen patients with posterior knee pain and without gross cartilage, meniscal, or ligamentous abnormalities all revealed an increased signal in this fat pad in fluid-sensitive fat-suppressed images, mainly in the sagittal and axial planes. In eight cases, enhancement of this fat pad was demonstrated following intravenous gadolinium administration. The pericruciate fat pad is a structure located in the intercondylar fossa, intimate with both the anterior and posterior cruciate ligaments. Inflammatory changes in this fat pad may be found in patients, especially athletes with posterior knee pain. (orig.)

  19. Lily Pad: Towards Real-time Interactive Computational Fluid Dynamics

    CERN Document Server

    Weymouth, Gabriel D

    2015-01-01

    Despite the fact that computational fluid dynamics (CFD) software is now (relatively) fast and freely available, it is still amazingly difficult to use. Inaccessible software imposes a significant entry barrier on students and junior engineers, and even senior researchers spend less time developing insights and more time on software issues. Lily Pad was developed as an initial attempt to address some of these problems. The goal of Lily Pad is to lower the barrier to CFD by adopting simple high-speed methods, utilising modern programming features and environments, and giving immediate visual feed-back to the user. The resulting software focuses on the fluid dynamics instead of the computation, making it useful for both education and research. LilyPad is open source and available online at https://github.com/weymouth/lily-pad for all use under the MIT license.

  20. Review of Tour of the Nile [iPad App

    Directory of Open Access Journals (Sweden)

    Helen Strudwick

    2013-07-01

    Full Text Available A review of the iPad app, Tour of the Nile. The app promises 'a virtual journey along the Nile Valley' plus the chance to 'handle' objects through the technology of augmented reality.

  1. Preventive medicine oversight of splash pads on military installations.

    Science.gov (United States)

    Hardcastle, Lisa Raysby; Perry, Matthew; Browne, Ashley

    2015-01-01

    Over the past several years, an increasing number of military installations have installed splash pads that provide fun, recreational water entertainment for Soldiers and their families. The addition of splash pads brings added responsibilities for medical treatment facility preventive medicine oversight and installation facilities maintenance to ensure a safe and healthy environment. Currently, there are no consistent standards or detailed guidance for military installations to follow when installing and maintaining splash pads. The central issues associated with splash pads on military installations are water quality and risk for waterborne illnesses, responsibility for safety and health oversight, and federal energy and water sustainability mandates. This article examines the importance of implementing a standard for design and oversight to ensure the health and safety of Soldiers and their families.

  2. Protected Areas Database of the United States (PAD-US)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS Protected Areas Database of the United States (PAD-US) is the nation's inventory of protected areas, including public open space and voluntarily provided,...

  3. On the Design of Tilting-Pad Thrust Bearings

    DEFF Research Database (Denmark)

    Heinrichson, Niels

    2007-01-01

    Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous...... friction and a small pressure build-up. As in parallel-step bearings the recesses may also have a depth of the same order of magnitude as the oil film thickness. Such recesses are characterized by a strong pressure build-up caused by the reduction of the flow area at the end of the recess. Numerical models...... based on the Reynolds equation are used. They include the effects of variations of viscosity with temperature and the deformation of the bearing pads due to pressure and thermal gradients. The models are validated using measurements. Tilting-pad bearings of standard design are studied and the influences...

  4. Biomechanical analysis of padding in child seats and head injury.

    Science.gov (United States)

    Kumaresan, Srirangam; Sances, Anthony; Carlin, Fred

    2002-01-01

    Head injury is a common finding for infants and young children involved in automobile accidents. Although the child restraint seats have increased the level of safety for the pediatric population, skull fracture and/or brain injury occur during the interaction between the child's head and interior of the car seats with no padding. The introduction of effective and sufficient padding may significantly reduce the head injury. The present study was designed to evaluate the biomechanical effects of padding in child seats to reduce the potential for head injury. A head drop test of a six-month old anthropomorphic dummy was conducted. The side of the dummy head impacted the interior wing of child car seats of relatively soft and stiff materials, and a rigid metal plate at velocities of 2.2, 4.5 and 6.7 m/s. In all tests, three types of padding environments were used (no padding, comfort foam, 16 to 19 mm polypropylene padding). All data were collected at 10 kHz and filtered. A total of 39 tests were conducted. The head injury criteria (HIC), and head acceleration, and head angular acceleration were obtained. The HIC was calculated over a 36 ms interval from the resultant tri-axial acceleration. The angular accelerations were derived from the angular velocity data. The head injury biomechanical parameters decreased with the addition of padding. The HIC, peak acceleration, and angular acceleration were reduced up to 91%, 80%, and 61% respectively. The present results emphasize the importance of energy absorbing padding to provide an improved safety environment in child car seats.

  5. Proof Pad: A New Development Environment for ACL2

    Directory of Open Access Journals (Sweden)

    Caleb Eggensperger

    2013-04-01

    Full Text Available Most software development projects rely on Integrated Development Environments (IDEs based on the desktop paradigm, with an interactive, mouse-driven user interface. The standard installation of ACL2, on the other hand, is designed to work closely with Emacs. ACL2 experts, on the whole, like this mode of operation, but students and other new programmers who have learned to program with desktop IDEs often react negatively to the process of adapting to an unfamiliar form of interaction. This paper discusses Proof Pad, a new IDE for ACL2. Proof Pad is not the only attempt to provide ACL2 IDEs catering to students and beginning programmers. The ACL2 Sedan and DrACuLa systems arose from similar motivations. Proof Pad builds on the work of those systems, while also taking into account the unique workflow of the ACL2 theorem proving system. The design of Proof Pad incorporated user feedback from the outset, and that process continued through all stages of development. Feedback took the form of direct observation of users interacting with the IDE as well as questionnaires completed by users of Proof Pad and other ACL2 IDEs. The result is a streamlined interface and fast, responsive system that supports using ACL2 as a programming language and a theorem proving system. Proof Pad also provides a property-based testing environment with random data generation and automated interpretation of properties as ACL2 theorem definitions.

  6. Modeling of Tilting-Pad Journal Bearings with Transfer Functions

    Directory of Open Access Journals (Sweden)

    J. A. Vázquez

    2001-01-01

    Full Text Available Tilting-pad journal bearings are widely used to promote stability in modern rotating machinery. However, the dynamics associated with pad motion alters this stabilizing capacity depending on the operating speed of the machine and the bearing geometric parameters, particularly the bearing preload. In modeling the dynamics of the entire rotor-bearing system, the rotor is augmented with a model of the bearings. This model may explicitly include the pad degrees of freedom or may implicitly include them by using dynamic matrix reduction methods. The dynamic reduction models may be represented as a set of polynomials in the eigenvalues of the system used to determine stability. All tilting-pad bearings can then be represented by a fixed size matrix with polynomial elements interacting with the rotor. This paper presents a procedure to calculate the coefficients of polynomials for implicit bearing models. The order of the polynomials changes to reflect the number of pads in the bearings. This results in a very compact and computationally efficient method for fully including the dynamics of tilting-pad bearings or other multiple degrees of freedom components that interact with rotors. The fixed size of the dynamic reduction matrices permits the method to be easily incorporated into rotor dynamic stability codes. A recursive algorithm is developed and presented for calculating the coefficients of the polynomials. The method is applied to stability calculations for a model of a typical industrial compressor.

  7. Preparation of solder pads by selective laser scanning

    Institute of Scientific and Technical Information of China (English)

    Wenqing Shi; Yongqiang Yang; Yanlu Huang; Guoqiang Wei; Wei Guo

    2009-01-01

    We propose a new laser preparation technique to solder Sn-Ag3.5-Cu0.7 on a copper clad laminate (CCL). The experiment is conducted by selective laser heating and melting the thin solder layer and then preprint-ing it on CCL in order to form the matrix with solder pads. Through the analysis of macro morphology of the matrix with solder pads and microstructure of single pads, this technique is proved to be suitable for preparing solder pads and that the solder pads are of good mechanical properties. The results also reveal that high frequency laser pulse is beneficial to the formation of better solder pad, and that the 12-W fiber laser with a beam diameter of 0.030 mm can solder Sn-Ag3.5-Cu0.7 successfully on CCL at 500-kHz pulse frequency. The optimized parameters of laser soldering on CCL are as follows: the laser power is 12 W, the scanning speed is 1.0 mm/s, the beam diameter is 0.030 mm, the lead-free solder is Sn-Ag3.5-Cu0.7, and the laser pulse frequency is 500 kHz.

  8. Pad Plane Design and Readout for SAMURAI TPC

    Science.gov (United States)

    Barney, J.; Chajecki, Z.; Chan, C. F.; Dunn, J. W.; Estee, J.; Gilbert, J.; Lu, F.; Lynch, W. G.; Shane, R.; Tsang, M. B.; McIntosh, A. B.; Yenello, S. J.; Famiano, M.; Isobe, T.; Sakurai, H.; Taketani, A.; Murakami, T.; Samurai-Tpc Collaboration

    2011-10-01

    The SAMURAI TPC is being built at Michigan State University to be used in the SAMURAI spectrometer at RIKEN in Japan, as part of the Symmetry Energy project, which focuses on obtaining constraints on the symmetry energy at supra-saturation densities. The presentation will discuss the development of the TPC as well as design for readout plane design for the TPC. These involve enabling the use of existing and future front end electronics (FEE), making the most of limited space, designing a circuit board for the pad plane, and techniques to glue the pad plane. The pad plane has been designed to work with either STAR or AGET electronics. The pad plane is made of a circuit board designed to minimize crosstalk and capacitance. The board must be built in smaller pieces and tiled, using alignment pins and precision gluing. Prototypes for the pad plane to FEE connection, pad plane gluing and STAR card mounting will be presented. Supported by the Department of Energy under Grant DE-SC0004835.

  9. The CIMSS iPad Library and ESIP Teacher Workshops

    Science.gov (United States)

    Dahlman, L.; Mooney, M. E.

    2012-12-01

    The Cooperative Institute for Meteorological Satellite Studies (CIMSS) at the University of Wisconsin-Madison launched a new initiative in 2012 to engage teachers and students in data acquisition and regional climate studies. The CIMSS iPad Library, part of a NASA funded Climate Literacy Ambassadors project, loans iPads to science teachers for an entire school year. The first units were distributed at a NOAA funded teacher workshop conducted at the annual Earth Science Information Partners (ESIP) summer conference. Educators learned about numerous NOAA and NASA resources at the ESIP Teacher Workshop and also several different climate-related Apps, including SatCam, an application for iOS devices that allows users to collect observations of local cloud and surface conditions coordinated with an overpass of the Terra, Aqua, or Suomi NPP satellite. This presentation will outline connections between the Climate Literacy Ambassadors community and ESIP Teacher Workshops before delving into details about the new iPad Library and SatCam. We will discuss considerations and challenges related to a technology loaning library, software recoding to HTML5, and some advantages and limitations related to iPads. We will also share feedback acquired over the fall from ESIP Educators using the SatCam App with their students with the iPads they borrowed (like books) from the CIMSS iPad Library.

  10. Aircraft Conceptual Design Using Vehicle Sketch Pad

    Science.gov (United States)

    Fredericks, William J.; Antcliff, Kevin R.; Costa, Guillermo; Deshpande, Nachiket; Moore, Mark D.; Miguel, Edric A. San; Snyder, Alison N.

    2010-01-01

    Vehicle Sketch Pad (VSP) is a parametric geometry modeling tool that is intended for use in the conceptual design of aircraft. The intent of this software is to rapidly model aircraft configurations without expending the expertise and time that is typically required for modeling with traditional Computer Aided Design (CAD) packages. VSP accomplishes this by using parametrically defined components, such as a wing that is defined by span, area, sweep, taper ratio, thickness to cord, and so on. During this phase of frequent design builds, changes to the model can be rapidly visualized along with the internal volumetric layout. Using this geometry-based approach, parameters such as wetted areas and cord lengths can be easily extracted for rapid external performance analyses, such as a parasite drag buildup. At the completion of the conceptual design phase, VSP can export its geometry to higher fidelity tools. This geometry tool was developed by NASA and is freely available to U.S. companies and universities. It has become integral to conceptual design in the Aeronautics Systems Analysis Branch (ASAB) here at NASA Langley Research Center and is currently being used at over 100 universities, aerospace companies, and other government agencies. This paper focuses on the use of VSP in recent NASA conceptual design studies to facilitate geometry-centered design methodology. Such a process is shown to promote greater levels of creativity, more rapid assessment of critical design issues, and improved ability to quickly interact with higher order analyses. A number of VSP vehicle model examples are compared to CAD-based conceptual design, from a designer perspective; comparisons are also made of the time and expertise required to build the geometry representations as well.

  11. 21 CFR 884.5425 - Scented or scented deodorized menstrual pad.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Scented or scented deodorized menstrual pad. 884... Therapeutic Devices § 884.5425 Scented or scented deodorized menstrual pad. (a) Identification. A scented or scented deodorized menstrual pad is a device that is a pad made of cellulosic or synthetic material...

  12. Climate Based Performance of Carbon-Carbon Disc Brake for High Speed Aircraft Braking System

    Directory of Open Access Journals (Sweden)

    R. M. Mohanty

    2013-09-01

    Full Text Available Carbon composite brake discs are lighter, economical, and have excellent high energy friction characteristics. These have twice thermal capability compared to steel, remain unaffected by thermal shocks and mechanical fatigue. These are highly useful in emergency breaking situations. Prior to this work, two dimensional (2D reinforced carbon composite laminates were prepared through pitch impregnation process. In an effort to protect the exposed non frictional surface from high temperature service degradations, multilayered ceramic coating systems were developed on 2D composite. Oxidation studies have been carried out on these systems viz., C-SiC, C-SiC-MoSi2-Al2O3 and C-SiC-B4C. These were performed both in dynamic and static conditions up to 1200 °C in 60 per cent humid climate. The hardness, surface topography, developed phases and integrity of layers on the samples at various stages of the experiment have been characterized and analyzed. It was observed that C-SiC-B4C system performs well in the oxidizing environment.Defence Science Journal, 2013, 63(5, pp.531-538, DOI:http://dx.doi.org/10.14429/dsj.63.3932

  13. Heavy and Overweight Vehicle Brake Testing: Five-Axle Combination Tractor-Flatbed Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Capps, Gary J [ORNL; Franzese, Oscar [ORNL

    2013-10-01

    The Federal Motor Carrier Safety Administration, in coordination with the Federal Highway Administration, sponsored the Heavy and Overweight Vehicle Brake Testing (HOVBT) program in order to provide information about the effect of gross vehicle weight (GVW) on braking performance. Because the Federal Motor Carrier Safety Regulations limit the number of braking system defects that may exist for a vehicle to be allowed to operate on the roadways, the examination of the effect of brake defects on brake performance for increased loads is also relevant. The HOVBT program seeks to provide relevant information to policy makers responsible for establishing load limits, beginning with providing test data for a combination tractor/trailer. This testing was conducted on a five-axle combination vehicle with tractor brakes meeting the Reduced Stopping Distance requirement rulemaking. This report provides a summary of the testing activities, the results of various analyses of the data, and recommendations for future research. Following a complete brake rebuild, instrumentation, and brake burnish, stopping tests were performed from 20 and 40 mph with various brake application pressures (15 psi, 25 psi, 35 psi, 45 psi, 55 psi, and full system pressure). These tests were conducted for various brake conditions at the following GVWs: 60,000, 80,000, 91,000, 97,000, 106,000, and 116,000 lb. The 80,000-lb GVWs included both balanced and unbalanced loads. The condition of the braking system was also varied. To introduce these defects, brakes (none, forward drive axle, or rear trailer axle) were made inoperative. In addition to the stopping tests, performance-based brake tests were conducted for the various loading and brake conditions. Analysis of the stopping test data showed the stopping distance to increase with load (as expected) and also showed that more braking force was generated by the drive axle brakes than the trailer axle brakes. The constant-pressure stopping test data

  14. 基于瞬态分析法的轮盘制动系统摩擦自激振动研究%Study on Friction-induced Self-excited Vibration of a Wheel-disc Brake System Using Transient Analysis Method

    Institute of Scientific and Technical Information of China (English)

    黄盼盼; 陈光雄; 莫继良

    2014-01-01

    There are two analysis methodologies available for predicting brake squeal using the finite element method, namely,complex eigenvalue analysis method and dynamic transient analysis method. Not all the unstable frequency ob-tained using complex eigenvalue analysis method can be observed in experiments,while transient analysis method is able to predict real unstable frequency in theory. A transient dynamic model of a wheel-disc brake system of EMU was estab-lished to study friction-induced self-excited vibration of the brake system,in which the friction coupling between brake pads and disc was imposed. Results show that the value of the dominant vibration frequency of the contact force between the brake pad and disc is consistent with that of the normal vibration of the brake pad. The dominant vibration frequency obtained by the transient analysis method is very close to the value of the unstable frequency obtained by the complex ei-genvalue method.%在制动噪声的有限元分析方法中,复特征值方法预测得到的不稳定频率过于保守,而瞬态分析方法在理论上可以得到较为真实的不稳定频率。考虑制动闸片与制动盘接触点间的摩擦力耦合作用,基于建立的高速动车轮盘制动系统的有限元模型,采用瞬态分析法对高速动车轮盘制动系统进行摩擦自激振动分析,并与复特征值分析法得到结果的进行比较。结果表明,接触面间法向接触力的振动主频与闸片法向振动的主频一致;制动系统瞬态动力学分析得到的振动主频与其复特征值分析得到的不稳定频率基本相符。

  15. Study on the dynamic characteristics of a high frequency brake based on giant magnetostrictive material

    Science.gov (United States)

    Xu, Ai Qun

    2016-06-01

    In order to meet the requirements of rapid and smooth braking, high-frequency braking using a giant magnetostrictive actuator is proposed, which can solve the problems in hydraulic braking, such as, it leaks easily, catches fire easily, is difficult to find failures, high cost on maintenance and repairing, etc. The main factors affecting the force of a high-frequency braking actuator are emphatically analyzed, the brakes dynamic model is established and a performance testing device for high frequency braking is constructed based on LabVIEW. The output force of the actuator increases with the excitation current of the driving coil increasing, and the increased multiple of the output force is greater than that of the excitation current; the range of the actuator force amplitude is 121.63 N ∼ 158.14 N, which changes little, while excitation frequency changes between 200 Hz ∼ 1000 Hz. In a minor range of pre-stress, the output force decreases with an increase in the axial pre-stress of the giant magnetostrictive rod, but is not obvious. It is known by finite element simulation analysis that high-frequency braking shortens the braking displacement and time effectively, which proves the feasibility and effectiveness of high frequency braking. Theoretical analysis and experimental results indicate that the output force of the actuator changes at the same frequency with excitation current; it is controllable and its mechanical properties meet the requirements of high frequency braking.

  16. Diagnostics monitor of the braking efficiency in the on board diagnostics system for the motor vehicles

    Science.gov (United States)

    Gajek, Andrzej

    2016-09-01

    The article presents diagnostics monitor for control of the efficiency of brakes in various road conditions in cars equipped with pressure sensor in brake (ESP) system. Now the brake efficiency of the vehicles is estimated periodically in the stand conditions on the base of brake forces measurement or in the road conditions on the base of the brake deceleration. The presented method allows to complete the stand - periodical tests of the brakes by current on board diagnostics system OBD for brakes. First part of the article presents theoretical dependences between deceleration of the vehicle and brake pressure. The influence of the vehicle mass, initial speed of braking, temperature of brakes, aerodynamic drag, rolling resistance, engine resistance, state of the road surface, angle of the road sloping on the deceleration have been analysed. The manner of the appointed of these parameters has been analysed. The results of the initial investigation have been presented. At the end of the article the strategy of the estimation and signalization of the irregular value of the deceleration are presented.

  17. Inhibition of PAD4 activity is sufficient to disrupt mouse and human NET formation

    Science.gov (United States)

    Lewis, Huw D.; Liddle, John; Coote, Jim E.; Atkinson, Stephen J.; Barker, Michael D.; Bax, Benjamin, D.; Bicker, Kevin L.; Bingham, Ryan P.; Campbell, Matthew; Chen, Yu Hua; Chung, Chun-wa; Craggs, Peter D.; Davis, Rob P.; Eberhard, Dirk; Joberty, Gerard; Lind, Kenneth E.; Locke, Kelly; Maller, Claire; Martinod, Kimberly; Patten, Chris; Polyakova, Oxana; Rise, Cecil E.; Rüdiger, Martin; Sheppard, Robert J.; Slade, Daniel J.; Thomas, Pamela; Thorpe, Jim; Yao, Gang; Drewes, Gerard; Wagner, Denisa D.; Thompson, Paul R.; Prinjha, Rab K.; Wilson, David M.

    2015-01-01

    PAD4 has been strongly implicated in the pathogenesis of autoimmune, cardiovascular and oncological diseases, through clinical genetics and gene disruption in mice. Novel, selective PAD4 inhibitors binding to a calcium-deficient form of the PAD4 enzyme have, for the first time, validated the critical enzymatic role of human and mouse PAD4 in both histone citrullination and neutrophil extracellular trap formation. The therapeutic potential of PAD4 inhibitors can now be explored. PMID:25622091

  18. Performance evaluation of three different types of local evaporative cooling pads in greenhouses in Sudan

    OpenAIRE

    Ahmed, Egbal Mohammed; Abaas, Osama; Ahmed, Mohammed; Ismail, Mohd Rodzi

    2010-01-01

    This study was conducted in Date Palm Technology Company Limited, Shambat, Khartoum State. To evaluate performance of three types of evaporative cooling pads for greenhouses (celdek pads, straw pads and sliced wood pads), as compared to the conditions outside the greenhouses (control), for pads. Performance evaluation includes environmental parameters (temperature and relative humidity at 8 am, 1 pm and 6 pm) and crop parameters (length and stem diameter, leaves number and width, fruit length...

  19. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    Science.gov (United States)

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  20. Can non-ideal magnetohydrodynamics solve the magnetic braking catastrophe?

    CERN Document Server

    Wurster, James; Bate, Matthew R

    2015-01-01

    We investigate whether or not the low ionisation fractions in molecular cloud cores can solve the `magnetic braking catastrophe', where magnetic fields prevent the formation of circumstellar discs around young stars. We perform three-dimensional smoothed particle non-ideal magnetohydrodynamics (MHD) simulations of the gravitational collapse of one solar mass molecular cloud cores, incorporating the effects of ambipolar diffusion, Ohmic resistivity and the Hall effect alongside a self-consistent calculation of the ionisation chemistry assuming 0.1 micron grains. When including only ambipolar diffusion or Ohmic resistivity, discs do not form in the presence of strong magnetic fields, similar to the cases using ideal MHD. With the Hall effect included, disc formation depends on the direction of the magnetic field with respect to the rotation vector of the gas cloud. When the vectors are aligned, strong magnetic braking occurs and no disc is formed. When the vectors are anti-aligned, a disc with radius of 13AU ca...

  1. Tearing mode velocity braking due to resonant magnetic perturbations

    Science.gov (United States)

    Frassinetti, L.; Menmuir, S.; Olofsson, K. E. J.; Brunsell, P. R.; Drake, J. R.

    2012-10-01

    The effect of resonant magnetic perturbations (RMPs) on the tearing mode (TM) velocity is studied in EXTRAP T2R. Experimental results show that the RMP produces TM braking until a new steady velocity or wall locking is reached. The braking is initially localized at the TM resonance and then spreads to the other TMs and to the rest of the plasma producing a global velocity reduction via the viscous torque. The process has been used to experimentally estimate the kinematic viscosity profile, in the range 2-40 m2 s-1, and the electromagnetic torque produced by the RMP, which is strongly localized at the TM resonance. Experimental results are then compared with a theoretical model which gives a reasonable qualitative explanation of the entire process.

  2. Analysis of natural frequency variability of a brake component

    Science.gov (United States)

    Gallina, A.; Lisowski, W.; Pichler, L.; Stachowski, A.; Uhl, T.

    2012-10-01

    The manufacture of automotive disc brake calipers is subjected to many inherent variabilities resulting in product variability. In particular, the dispersion of natural frequency values is a primary issue in the context of vehicle comfort. This paper aims to quantify natural frequency variability and search for its causes. Extensive experimental tests and numerical simulations, described in the paper, point out the fundamental role of mold wear and assembling process in this variability.

  3. Subway Train Braking System: A Fuzzy Based Hardware Approach

    Directory of Open Access Journals (Sweden)

    Mamun B.I. Reaz

    2011-01-01

    Full Text Available Problem statement: Automated subway train-braking system require perfection, efficiency and fast response. In order to cope with this concerns, an appropriate algorithm need to be developed which need to be implemented in hardware for faster response. Approach: In this research, the FPGA realization of fuzzy based subway train braking system has been presented on an Alter FLEX10K device to provide an accurate and increased speed of convergence of the network. The fuzzy based subway train braking system is comprised of fusilier, inference, rule selector and defuzzifier modules. Sixteen rules are identified for the rule selector module. After determining the membership functions and its fuzzy variables, the Max-Min Composition method and Madman-Min implication operator are used for the inference module and the Centre of Gravity method is used for the defuzzification module. Each module is modeled individually using behavioral VHDL. The layers are then connected using structural VHDL. Two 8-bit and one 8-bit unsigned digital signals are used for input and output respectively. Six ROMs are defined in order to decrease the chances of processing and increasing the throughput of the system. Results: Functional simulations were commenced to verify the functionality of the individual modules and the system as well. We have validated the hardware implementation of the proposed approach through comparison, verification and analysis. The design has utilized 2372 units of LC with a system frequency of 139.8MHz. Conclusion: In this research, the FPGA realization of fuzzy brake system of subway train has been successfully implemented with minimum usage of logic cells. The validation study with C model shows that the hardware model is appropriate and the hardware approach shows faster and accurate response with full automatic control.

  4. Adaptive Brake By Wire: From Human Factors to Adaptive Implementation

    OpenAIRE

    Spadoni, Andrea

    2013-01-01

    The introduction of the Brake By Wire is replacing the traditional mechanical control systems with ECUs and it is raising the need to reproduce feelings of eliminated static mechanical components (i.e. hydraulic fluids, pumps and cylinders). Thanks to electromechanical actuators and human-machine interfaces (i.e. active pedal) it is possible to reproduce such feelings and, therefore, arbitrarily change their features. In this way it will be possible to customize the pedal feelings and the veh...

  5. Slide Mode Control for Integrated Electric Parking Brake System

    OpenAIRE

    Bin Wang; Xuexun Guo; Chengcai Zhang; Zhe Xiong; Huan Xia; Jie Zhang

    2013-01-01

    The emerging integrated electric parking brake (IEPB) system is introduced and studied. Through analyzing the various working stages, the stages switched IEPB system models are given with the consideration of the friction and system idle inertia. The sliding mode control (SMC) method is adopted to control the clamping force by the widely used motor angle and clamping force relationship method. Based on the characteristics of the state equations, two sliding surfaces are built to control the m...

  6. Carbon nanotube torsional springs for regenerative braking systems

    Science.gov (United States)

    Liu, Sanwei; Martin, Corbin; Lashmore, David; Schauer, Mark; Livermore, Carol

    2015-10-01

    The modeling and demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as energy-storing actuators for regenerative braking systems. An originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing incrementally until failure. The measured average extractable energy density values are 2.9 kJ kg-1  ±  1.2 kJ kg-1 and 3.4 kJ kg-1  ±  0.4 kJ kg-1 for 1-ply CNT yarns and 2-ply CNT yarns, respectively. Additionally, a regenerative braking system is demonstrated to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yarn’s twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking setup are on average 3.3 kJ kg-1 and 0.67 kW kg-1, respectively, with maximum measured values of up to 4.7 kJ kg-1 and 1.2 kW kg-1, respectively. A slightly lower energy density of up to 1.2 kJ kg-1 and a 0.29 kW kg-1 mean power density are measured for CNT yarns in a more complex setup that mimics a unidirectional rotating regenerative braking mechanism.

  7. A Combined Cooperative Braking Model with a Predictive Control Strategy in an Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Hongqiang Guo

    2013-12-01

    Full Text Available Cooperative braking with regenerative braking and mechanical braking plays an important role in electric vehicles for energy-saving control. Based on the parallel and the series cooperative braking models, a combined model with a predictive control strategy to get a better cooperative braking performance is presented. The balance problem between the maximum regenerative energy recovery efficiency and the optimum braking stability is solved through an off-line process optimization stream with the collaborative optimization algorithm (CO. To carry out the process optimization stream, the optimal Latin hypercube design (Opt LHD is presented to discrete the continuous design space. To solve the poor real-time problem of the optimization, a high-precision predictive model based on the off-line optimization data of the combined model is built, and a predictive control strategy is proposed and verified through simulation. The simulation results demonstrate that the predictive control strategy and the combined model are reasonable and effective.

  8. An Investigation into Regenerative Braking Control Strategy for Hybrid Electric Vehicle

    Institute of Scientific and Technical Information of China (English)

    PENG Dong; YIN Cheng-liang; ZHANG Jian-wu

    2005-01-01

    Energy regeneration during braking is an important technique for hybrid electric vehicle (HEV) to improve their fuel economy and extend their driving range. Due to the effect of regenerative braking torque which is added by electric motor, the braking torque distribution between front and rear axles should be changed and the control logic of anti-lock braking system (ABS) ought to be adjusted according to the regenerative braking torque. This paper put forward a braking control strategy for hybrid electric vehicle; the control strategy is implemented with eight DOFs (Degree-of-Freedom) nonlinear vehicle forward simulation model which is built under the environment of Matlab/Simulink. Based on target wheel slip ratio, a fuzzy logic approach was applied to maintain the optimal target slip ratio so that best compromise between hydraulic torque and regenerative torque can be obtained for the vehicle.

  9. Design and analysis of the hybrid excitation rail eddy brake system of high-speed trains

    Institute of Scientific and Technical Information of China (English)

    Ji-en MA; Bin ZHANG; Xiao-yan HUANG; You-tong FANG; Wen-ping CAO

    2011-01-01

    Compared to the current eddy braking patterns using a single magnetic source,hybrid excitation rail eddy brakes have many advantages,such as controllability,energy saving,and various operating models.Considering the large braking power consumption of the high-speed train,a hybrid excitation rail eddy brake system,which is based on the principle of electromagnetic field,is proposed to fulfill the needs of safety and reliability.Then the working processes of the mechanical lifting system and electromagnetic system are demonstrated.With the electromagnetic system analyzed using the finite element method,the factors such as speed,air gap,and exciting current have influences on the braking force and attractive force.At last,the structure optimization of the brake system is discussed.

  10. 苹果发布新款iPad%Apple Unveils New iPad

    Institute of Scientific and Technical Information of China (English)

    Jefferson Graham

    2012-01-01

    苹果公司前不久刚刚发布了其最新的iPad。和预想的一样,第三代iPad有更清楚的显示屏和更快的处理器,有语音听写功能,并能适应更快的蜂窝网络。此次发布会之前,很多人猜测苹果的这款新设备会叫做"iPad 3"或者"高清iPad"。但是,苹果公司高管却简单地称它为"新款iPad"。

  11. Optimal design of a new multipole bilayer magnetorheological brake

    Science.gov (United States)

    Shiao, Yaojung; Ngoc, Nguyen Anh; Lai, Chien-Hung

    2016-11-01

    This article presents a new high-torque multipole bilayer magneto-rheological brake (MRB). This MRB has a unique structural design with multiple electromagnetic poles and multiple media layers of magnetorheological fluid (MRF). The MRB has two rotors located on the outer and inner sides of a six-pole stator, and therefore, it can provide higher torque and a larger torque-to-volume ratio (TVR) than conventional single- or multipole single-layer MRBs can. Moreover, the problem of potential MRF leakage is solved by using cylindrical separator rings around the stator. In this study, first, the structure of the proposed MRB is introduced. An analog magnetic circuit was built for the MRB to investigate the effects of the MRB parameters on the magnetic field intensity of the MRF layers. In addition, a 3D electromagnetic model of the MRB was developed to simulate and examine the magnetic flux intensity and corresponding braking torque. An approximate optimization method was then applied to obtain the optimal geometric dimensions for the major dimensional parameters of the MRB. The MRB was manufactured and tested to validate its torque and dynamic characteristics. The results showed that the proposed MRB exhibited great enhancement of the braking torque and TVR.

  12. Effects of Magnetic Braking and Tidal Friction on Hot Jupiters

    CERN Document Server

    Barker, A J

    2009-01-01

    Tidal friction is thought to be important in determining the long-term spin-orbit evolution of short-period extrasolar planetary systems. Using a simple model of the orbit-averaged effects of tidal friction Eggleton, Kiseleva & Hut (1998), we analyse the effects of the inclusion of stellar magnetic braking on the evolution of such systems. A phase-plane analysis of a simplified system of equations, including only the stellar tide together with a model of the braking torque proposed by Verbunt & Zwaan (1981), is presented. The inclusion of stellar magnetic braking is found to be extremely important in determining the secular evolution of such systems, and its neglect results in a very different orbital history. We then show the results of numerical integrations of the full tidal evolution equations, using the misaligned spin and orbit of the XO-3 system as an example, to study the accuracy of simple timescale estimates of tidal evolution. We find that it is essential to consider coupled evolution of th...

  13. A Predictive Distribution Model for Cooperative Braking System of an Electric Vehicle

    OpenAIRE

    Hongqiang Guo; Hongwen He; Xuelian Xiao

    2014-01-01

    A predictive distribution model for a series cooperative braking system of an electric vehicle is proposed, which can solve the real-time problem of the optimum braking force distribution. To get the predictive distribution model, firstly three disciplines of the maximum regenerative energy recovery capability, the maximum generating efficiency and the optimum braking stability are considered, then an off-line process optimization stream is designed, particularly the optimal Latin hypercube d...

  14. Thermo-Mechanical Simulation of Brake Disc Frictional Character by Moment of Inertia

    OpenAIRE

    Fei Gao

    2014-01-01

    The distribution of temperatures gradient and thermal stress of brake disc has been simulated by FEM code to make brake disc thermal stress more homogenously. In this study, using moment of inertia to simulate the realistic brake process instead of theoretically predefines the train deceleration rate, nonlinear deceleration rate and thermo-mechanical behavior has been revealed. The FEM models build upon LS-DYNA® thermo-mechanical code and contact algorithm. Non-uniform temperature alone disc ...

  15. Development of electronic diagnostic system for improving the diagnosis reliability of passenger car brakes

    OpenAIRE

    2016-01-01

    The mathematical model that allows determining the pressure in the brake cylinder, distributor chambers and auxiliary reservoir of the car depending on the absolute pressure changes in the air flow through the throttle openings for a scheduled time is developed in the paper for diagnosing the parameters of the brake system of the individual car or train. It is embedded in the hardware-software system algorithm. This allows simulating the operation of the serviceable brake equipment and provid...

  16. An approach of inertia compensation based on electromagnetic induction in brake test

    Directory of Open Access Journals (Sweden)

    Xiaowen Li

    2016-04-01

    Full Text Available This paper briefly introduced the operational principle of the brake test bench, and points out the shortcomings when controlling the current of brake test, which means the reference measuring data is instantaneous. Aimed at this deficiency, a current control model based on electromagnetic induction and DC voltage is proposed. On the principle of electromagnetic induction, continuous data and automatic processes are realized. It significantly minimized errors owing to instantaneous data, and maximized the accuracy of the brake test.

  17. Development of Parking Brake Component : Product Development and Mechanical Design Process

    OpenAIRE

    Rintamäki, Julia

    2013-01-01

    This report represents the bachelor thesis examination by Julia Kastehelmi Rintamäki. The examination has been performed during spring semester 2013 at Volvo Construction Equipment in Eskilstuna. This report, Development of parking brake component, describes the product development process of the parking brake component for articulated hauler, wheel loader and grader. Volvo CE has problems with the parking brake switch that exist today on articulated hauler, wheel loader and grader. The purpo...

  18. Visible light active photocatalyst from recycled disposable heating pads

    Science.gov (United States)

    Lee, Meng-Chien; Wang, Chun-Yu; Chen, Che-Chin; Wang, Chih-Ming; Hsiao, Ta-Chih; Tsai, Din Ping

    2016-01-01

    Alpha-Fe2O3 (α-Fe2O3) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe2O3. Here, we collect and purify the α-Fe2O3 powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H2 energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe2O3 is also investigated. It is found that H2 evolution rate can be enhanced 15% using α-Fe2O3 nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe2O3 nanoparticles coated without Au layer.

  19. Multi-angle deformation analysis of Hoffa's fat pad

    Science.gov (United States)

    Stevenson, Kevin; Schweitzer, Mark; Hamarneh, Ghassan

    2006-03-01

    Recent advances in medical research hypothesize that certain body fat, in addition to having a classical role of energy storage, may also have mechanical function. In particular, we analyzed the infrapatellar fat pad of Hoffa using 3D CT images of the knee at multiple angles to determine how the fat pad changes shape as the knee bends and whether the fat pad provides cushioning in the knee joint. The images were initially processed using a median filter then segmented using a region growing technique to isolate the fat pad from the rest of the knee. Next, rigid registration was performed to align the series of images to match the reference image. Finally, multi-resolution FEM registration was completed between the aligned images. The resulting displacements fields were used to determine the local volume change of the fat pad as the knee bends from extension to flexion through different angles. This multi-angle analysis provides a finer description of the intermediate deformations compared to earlier work, where only a pair of images (full extension and flexion) was analyzed.

  20. A Study on Control Strategy of Regenerative Braking in the Hydraulic Hybrid Vehicle Based on ECE Regulations

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2013-01-01

    Full Text Available This paper establishes a mathematic model of composite braking in the hydraulic hybrid vehicle and analyzes the constraint condition of parallel regenerative braking control algorithm. Based on regenerative braking system character and ECE (Economic Commission of Europe regulations, it introduces the control strategy of regenerative braking in parallel hydraulic hybrid vehicle (PHHV. Finally, the paper establishes the backward simulation model of the hydraulic hybrid vehicle in Matlab/simulink and makes a simulation analysis of the control strategy of regenerative braking. The results show that this strategy can equip the hydraulic hybrid vehicle with strong brake energy recovery power in typical urban drive state.

  1. Analysis of the stability of PTW riders in autonomous braking scenarios.

    Science.gov (United States)

    Symeonidis, Ioannis; Kavadarli, Gueven; Erich, Schuller; Graw, Matthias; Peldschus, Steffen

    2012-11-01

    While fatalities of car occupants in the EU decreased remarkably over the last decade, Powered Two Wheelers (PTWs) fatalities still increase following the increase of PTW ownership. Autonomous braking systems have been implemented in several types of vehicles and are presently addressed by research in the field of PTWs. A major concern in this context is the rider stability. Experiments with volunteers were performed in order to find out whether autonomous braking for PTWs will produce a greater instability of the rider in comparison to manual braking. The PTW's braking conditions were simulated in a laboratory with a motorcycle mock-up mounted on a sled, which was accelerated with an average of 0.35 g. The motion of the rider was captured in autonomous braking scenarios with and without pre-warning as well as in manual braking scenarios. No significant differences between the scenarios were found with respect to maximum forward displacement of the volunteer's torso and head (pautonomous braking at low deceleration will not cause significant instabilities of the rider in comparison to manual braking in idealized laboratory conditions. Based on this, further research into the development and implementation of autonomous braking systems for PTWs, e.g. by extensive riding tests, seems valuable.

  2. Real-Time Dynamic Brake Assessment Proof of Concept Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lascurain, Mary Beth [ORNL; Franzese, Oscar [ORNL; Capps, Gary J [ORNL

    2011-11-01

    This proof-of-concept research was performed to explore the feasibility of using real-world braking data from commercial motor vehicles to make a diagnosis of brake condition similar to that of the performance-based brake tester (PBBT). This was done by determining the relationship between pressure and brake force (P-BF), compensating for the gross vehicle weight (GVW). The nature of this P-BF relationship (e.g., low braking force for a given brake application pressure) may indicate brake system problems. In order to determine the relationship between brake force and brake application pressure, a few key parameters of duty cycle information were collected. Because braking events are often brief, spanning only a few seconds, a sample rate of 10 Hz was needed. The algorithm under development required brake application pressure and speed (from which deceleration was calculated). Accurate weight estimation was also needed to properly derive the braking force from the deceleration. In order to ensure that braking force was the predominant factor in deceleration for the segments of data used in analysis, the data was screened for grade as well. Also, the analysis needed to be based on pressures above the crack pressure. The crack pressure is the pressure below which the individual brakes are not applied due the nature of the mechanical system. This value, which may vary somewhat from one wheel end to another, is approximately 10 psi. Therefore, only pressures 15 psi and above were used in the analysis. The Department of Energy s Medium Truck Duty Cycle research has indicated that under the real-world circumstances of the test vehicle brake pressures of up to approximately 30 psi can be expected. Several different types of data were collected during the testing task of this project. Constant-pressure stopping tests were conducted at several combinations of brake application pressure (15, 20, 25, and 30 psi), load conditions (moderately and fully laden), and speeds (20 and

  3. 重载列车制动管路对制动性能的影响%Influence of braking pipe on braking performance for heavy haul train

    Institute of Scientific and Technical Information of China (English)

    魏伟; 杜念博

    2011-01-01

    应用流体动力学理论,建立了重载列车制动管路模型与分配阀模型,求解了制动管路和边界点的动力学方程,仿真计算了制动过程中的制动系统性能,分析了列车主管和支管长度对制动系统性能的影响。分析结果表明:当列车主管长度由13.24 m增大为17.24 m时,在常用制动下,列车管路减压时间增大了30.75%,制动缸升压时间增大了20.45%,主管长度对常用制动的影响要强于对紧急制动的影响;当列车支管长度由0.50 m增大到5.00 m时,在常用制动下,列车管路减压时间增大了6.63%,制动缸升压时间增大了5.22%,支管长度对常用制动和紧急制动影响程度差别不大。列车制动管路长度增大降低了列车制动管路减压速度与制动缸升压速度;列车主管长度对制动性能的影响要明显大于列车支管长度的影响,车辆位置距机车越远影响越明显。%With fluid dynamics theory,the models of braking pipe and distributing valve for heavy haul train were built,the equations of braking pipe and boundary point were solved,the braking system performances in braking process were simulated,and the influence of the lengths of main pipe and branch pipe on the braking performances was analyzed.Analysis result shows that under common braking,when the length of main pipe increases from 13.24 m to 17.24 m,the decompression time of braking pipe increases by 30.75%,and the boost time of braking cylinder increases by 20.45%.The influence of main pipe on common braking is even stronger than that of main pipe on emergency braking.Under common braking,when the length of branch pipe increases from 0.50 m to 5.00 m,the decompression time of braking pipe increases by 6.63%,and the boost time of braking cylinder increases by 5.22%.The influence of branch pipe on common braking is almost same for that of branch pipe on emergency braking.The increase length of braking pipe reduces the decompression speed of braking pipe

  4. 动态摩擦因数对蝶式制动器温度场影响的试验和模拟研究%Experimental and Simulation Research on the Influence of Dynamic Friction Coefficient to the Temperature Field of Disc Brake

    Institute of Scientific and Technical Information of China (English)

    周俊峰; 王伟; 张晨; 刘焜

    2016-01-01

    To research into temperature field of disc brake, as needed, a constant speed braking bench is developed to simulate the braking condition of motorcycle under long slope by similarity principle. The disc fixed on rotating shaft, which is clamped by three jaw chuck of lathe, rotate with constant speed. The disc is clamped by inner pad and outward pad though hydraulic pressure. Temperature evolution of certain point on outward pad, braking torque evolution, mean value of braking pressure, temperature evolution on the frictional area of disc are measured by thermal couple, pressure sensor, piezometer, thermal imager respectively. The braking bench could realize the dynamic test of all variables under different rational speed and different braking pressure. The maximum temperature is chosen as variable to research the evolution of friction coefficient with temperature increasing. Based on experiment, simulation and analysis are did by ABAQUS. Simulation models are made from actual model by the ratio 1:1, load and boundary conditions are the same as reality, the evolution of friction coefficient with increasing temperature is put into contact condition, finally, the evolutions of the temperature fields of disc and pad are obtained. Compare to the simulation result and experimental result, it shows that the contact model with dynamic friction coefficient is better fit into the actual braking condition.%针对蝶式制动器制动过程中温度场研究的需要,利用相似原理研制定速制动试验台,用以模拟摩托车匀速下长坡时的制动工况。制动试验台用车床的三爪卡盘控制固定在旋转轴上的制动盘做定速旋转运动,内外摩擦片通过液压力夹紧制动盘,使制动盘与摩擦片发生摩擦运动,通过热电偶、拉压力传感器、压力表、热成像仪分别测出定速制动50 s的摩擦片上固定点的温度变化、制动扭矩(经计算得出)的动态变化、制动力的均值、制动盘摩

  5. On pads and filters: Processing strong-motion data

    Science.gov (United States)

    Boore, D.M.

    2005-01-01

    Processing of strong-motion data in many cases can be as straightforward as filtering the acceleration time series and integrating to obtain velocity and displacement. To avoid the introduction of spurious low-frequency noise in quantities derived from the filtered accelerations, however, care must be taken to append zero pads of adequate length to the beginning and end of the segment of recorded data. These padded sections of the filtered acceleration need to be retained when deriving velocities, displacements, Fourier spectra, and response spectra. In addition, these padded and filtered sections should also be included in the time series used in the dynamic analysis of structures and soils to ensure compatibility with the filtered accelerations.

  6. The SciencePAD treasure hunt of Persistent Identifiers

    CERN Multimedia

    Beatrice Bressan, for the European Middleware Initiative (EMI)

    2013-01-01

    Have you ever followed a reference for an article that eventually turned out to be unavailable? Have you always thought that experiment data or research results should be permanently accessible? If so, you will probably be interested in the latest news on the current status of software and digital information issues, and you shouldn’t miss the SciencePAD Persistent Identifiers Workshop (SPID2013).   The workshop is being organised by the European Middleware Initiative (EMI) together with its SciencePAD (formerly known as ScienceSoft) project and will take place on 30 January 2013 at CERN. SciencePAD is a community-enabler, working on providing the necessary one-stop-shop tools, including software, catalogues, statistics, reference citation systems, marketplaces, technical services links, platform integration supports, etc. It allows researchers and open source software developers from scientific communities to interact with each other within and beyond their area of expertise, and co...

  7. Fast micro Hall effect measurements on small pads

    DEFF Research Database (Denmark)

    Østerberg, Frederik Westergaard; Petersen, Dirch Hjorth; Nielsen, Peter F.

    2011-01-01

    reference measurements, when only small sheet resistance variations are present. For samples with a sheet resistance variation of more than 5%, a more time consuming method must be used. Here, the theoretically expected measurement values are computed based on the sheet resistance variation using a finite...... pads is non-trivial. In this paper we discuss how conformal mapping can be used to evaluate theoretically expected measurement values on small pads. Theoretical values calculated from analytical mappings of simple geometries are compared to the values found from the numerical conformal mapping......Sheet resistance, carrier mobility, and sheet carrier density are important parameters in semiconductor production, and it is therefore important to be able to rapidly and accurately measure these parameters even on small samples or pads. The interpretation of four-point probe measurements on small...

  8. Tilting-Pad Guide Bearing in Large Hydro-unit

    Directory of Open Access Journals (Sweden)

    Li-Feng Ma

    2000-01-01

    Full Text Available A new numerical method is proposed for predicting the nonlinearity of tilting-pad guide bearing oilfilm force in the rotor-bearing system in a large hydro-unit. Nonlinear displacement and velocity of the journal center, as well as nonlinear tilting angles and angular velocities of the pads in non-stationary Reynolds equation are taken into account. This method is also suited for other small rotor-bearing system. As an example, the response due to a momentarily created unbalance is Calculated. The nonlinear motion patterns of the pad and journal whirling orbit are obtained. Finally, the nonlinear orbit is compared to the linear one that could be calculated from linear stiffness and damping coefficients. It is shown that there are important differences between those two orbits and that the nonlinear simulation is more accurate.

  9. iPads betydning for studerendes læring

    DEFF Research Database (Denmark)

    Bisgaard, Kirsten; Melander, Thomas; Sjøstedt, Peter

    Dette brief fremlægger resultaterne af en undersøgelse af iPads betydning for studerendes læring på Institut for Sprog ved Forsvarsakademiet. Undersøgelsen rejser en række pædagogiske og tekniske spørgsmål vedrørende anvendelse af iPads i undervisningen, der kan være relevante at drøfte og...... undersøge i forbindelse med anvendelse og anskaffelse af tablets i forbindelse med undervisning. Konklusionen på den gennemførte undersøgelse på Institut for Sprog er, at det lokale studiemiljø og de studerendes individuelle præferencer for teknologi og studieteknik har stor betydning for anvendelsen af iPads...

  10. SCIENTIFIC PROGRESS OF THE MC-PAD NETWORK

    CERN Document Server

    Aguilar, J; Ambalathankandy, P; Apostolakis, J; Arora, R; Balog, T; Behnke, T; Beltrame, P; Bencivenni, G; Caiazza, S; Dong, J; Heller, M; Heuser, J; Idzik, M; Joram, C; Klanner, R; Koffeman, E; Korpar, S; Kramberger, G; Lohmann, W; Milovanović, M; Miscetti, S; Moll, M; Novgorodova, O; Pacifico, N; Pirvutoiu, C; Radu, R; Rahman, S; Rohe, T; Ropelewski, L; Roukoutakis, F; Schmidt, C; Schön, R; Sibille, J; Tsagri, M; Turala, M; Van Beuzekom, M; Verheyden, R; Villa, M; Zappon, F; Zawiejski, L; Zhang, J

    2013-01-01

    MC-PAD is a multi-site Initial Training Network on particle detectors in physics experiments. It comprises nine academic participants, three industrial partners and two associated academic partners. 17 recruited Early Stage and 5 Experienced Researchers have performed their scientific work in the network. The research and development work of MC-PAD is organized in 12 work packages, which focus on a large variety of aspects of particle detector development, electronics as well as simulation and modelling. The network was established in November 2008 and lasted until October 2012 (48 months). This report describes the R&D activities and highlights the main results achieved during this period.

  11. The iPad as a Tool for Play

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    Over the last couple of years, tablets - especially Apple's iPad - have become more frequent as a new, truly mobile technology in school settings, day care institutions and private homes. Tablets are being used for numerous purposes, being a sort of mix between a ‘real’ computer and a mobile phone...... implications and challenges related to conducting ethnographically inspired fieldwork of people’s everyday uses of mobile technologies. What is interesting about the iPad as a tool - or a toy - is the way in which it invites and supports certain types of use, and how it contributes to new, emerging ways...

  12. Best iPad Apps The Guide for Discriminating Downloaders

    CERN Document Server

    Meyers, Peter

    2010-01-01

    What really wows iPad fans is when their touchscreen does what's impossible on other gadgets: the finger-painting app that turns a cross-country flight into a moving art class, the mini music studio (two-dozen instruments strong, each with motion-induced warble effects), and the portable fireworks display that you sculpt by swiping. Problem is, with tens of thousands of apps available for your iPad, who knows what to download? You can try to sort through a gazillion customer reviews with a mix of 5- and 1-star ratings, but that's a head-hurting time-waster. The stakes are getting higher, too

  13. PAD-US: National Inventory of Protected Areas

    Science.gov (United States)

    Gergely, Kevin J.; McKerrow, Alexa

    2013-11-12

    The Gap Analysis Program produces data and tools that help meet critical national challenges such as biodiversity conservation, renewable energy development, climate change adaptation, and infrastructure investment. The Protected Areas Database of the United States (PAD-US) is the official inventory of protected open space in the United States. With over 715 million acres in thousands of holdings, the spatial data in PAD-US include public lands held in trust by national, State, and some local governments, and by some nonprofit conservation organizations.

  14. Cellular Activity of New Small Molecule Protein Arginine Deiminase 3 (PAD3) Inhibitors.

    Science.gov (United States)

    Jamali, Haya; Khan, Hasan A; Tjin, Caroline C; Ellman, Jonathan A

    2016-09-08

    The protein arginine deiminases (PADs) catalyze the post-translational deimination of arginine side chains. Multiple PAD isozymes have been characterized, and abnormal PAD activity has been associated with several human disease states. PAD3 has been characterized as a modulator of cell growth via apoptosis inducing factor and has been implicated in the neurodegenerative response to spinal cord injury. Here, we describe the design, synthesis, and evaluation of conformationally constrained versions of the potent and selective PAD3 inhibitor 2. The cell activity of representative inhibitors in this series was also demonstrated for the first time by rescue of thapsigargin-induced cell death in PAD3-expressing HEK293T cells.

  15. Analysis of heat conduction in a drum brake system of the wheeled armored personnel carriers

    Science.gov (United States)

    Puncioiu, A. M.; Truta, M.; Vedinas, I.; Marinescu, M.; Vinturis, V.

    2015-11-01

    This paper is an integrated study performed over the Braking System of the Wheeled Armored Personnel Carriers. It mainly aims to analyze the heat transfer process which is present in almost any industrial and natural process. The vehicle drum brake systems can generate extremely high temperatures under high but short duration braking loads or under relatively light but continuous braking. For the proper conduct of the special vehicles mission in rough terrain, we are talking about, on one hand, the importance of the possibility of immobilization and retaining position and, on the other hand, during the braking process, the importance movement stability and reversibility or reversibility, to an encounter with an obstacle. Heat transfer processes influence the performance of the braking system. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of analyzed vehicle wheels. In the present work a finite element model for the temperature distribution in a brake drum is developed, by employing commercial finite element software, ANSYS. These structural and thermal FEA models will simulate entire braking event. The heat generated during braking causes distortion which modifies thermoelastic contact pressure distribution drum-shoe interface. In order to capture the effect of heat, a transient thermal analysis is performed in order to predict the temperature distribution transitional brake components. Drum brakes are checked both mechanical and thermal. These tests aim to establish their sustainability in terms of wear and the variation coefficient of friction between the friction surfaces with increasing temperature. Modeling using simulation programs led eventually to the establishment of actual thermal load of the mechanism of brake components. It was drawn the efficiency characteristic by plotting the coefficient of effectiveness relative to the coefficient of friction shoe-drum. Thus induced

  16. To a question of an estimation of possibilities and efficiency of various kinds of electric braking of industrial electric locomotives

    OpenAIRE

    Sinchuk, O. N.; Sinchuk, I. O.; Jakimets, S. N.; Kljuchka, A. S.

    2010-01-01

    The analysis of efficiency of the use of different types of the electric braking by the hauling electromechanics of mines electric locomotives is resulted. Efficiency of the electrodynamic braking is led to. The schemotechnycs decisions are resulted.

  17. Energy-Regenerative Braking Control of Electric Vehicles Using Three-Phase Brushless Direct-Current Motors

    OpenAIRE

    Bo Long; Shin Teak Lim; Ji Hyoung Ryu; Kil To Chong

    2013-01-01

    Regenerative braking provides an effective way of extending the driving range of battery powered electric vehicles (EVs). This paper analyzes the equivalent power circuit and operation principles of an EV using regenerative braking control technology. During the braking period, the switching sequence of the power converter is controlled to inverse the output torque of the three-phase brushless direct-current (DC) motor, so that the braking energy can be returned to the battery. Compared with ...

  18. Product Quality Improvement Using FMEA for Electric Parking Brake (EPB)

    Science.gov (United States)

    Dumitrescu, C. D.; Gruber, G. C.; Tişcă, I. A.

    2016-08-01

    One of the most frequently used methods to improve product quality is complex FMEA. (Failure Modes and Effects Analyses). In the literature various FMEA is known, depending on the mode and depending on the targets; we mention here some of these names: Failure Modes and Effects Analysis Process, or analysis Failure Mode and Effects Reported (FMECA). Whatever option is supported by the work team, the goal of the method is the same: optimize product design activities in research, design processes, implementation of manufacturing processes, optimization of mining product to beneficiaries. According to a market survey conducted on parts suppliers to vehicle manufacturers FMEA method is used in 75%. One purpose of the application is that after the research and product development is considered resolved, any errors which may be detected; another purpose of applying the method is initiating appropriate measures to avoid mistakes. Achieving these two goals leads to a high level distribution in applying, to avoid errors already in the design phase of the product, thereby avoiding the emergence and development of additional costs in later stages of product manufacturing. During application of FMEA method using standardized forms; with their help will establish the initial assemblies of product structure, in which all components will be viewed without error. The work is an application of the method FMEA quality components to optimize the structure of the electrical parking brake (Electric Parching Brake - E.P.B). This is a component attached to the roller system which ensures automotive replacement of conventional mechanical parking brake while ensuring its comfort, functionality, durability and saves space in the passenger compartment. The paper describes the levels at which they appealed in applying FMEA, working arrangements in the 4 distinct levels of analysis, and how to determine the number of risk (Risk Priority Number); the analysis of risk factors and established

  19. A New Model of Stopping Sight Distance of Curve Braking Based on Vehicle Dynamics

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2016-01-01

    Full Text Available Compared with straight-line braking, cornering brake has longer braking distance and poorer stability. Therefore, drivers are more prone to making mistakes. The braking process and the dynamics of vehicles in emergency situations on curves were analyzed. A biaxial four-wheel vehicle was simplified to a single model. Considering the braking process, dynamics, force distribution, and stability, a stopping sight distance of the curve braking calculation model was built. Then a driver-vehicle-road simulation platform was built using multibody dynamic software. The vehicle test of brake-in-turn was realized in this platform. The comparison of experimental and calculated values verified the reliability of the computational model. Eventually, the experimental values and calculated values were compared with the stopping sight distance recommended by the Highway Route Design Specification (JTGD20-2006; the current specification of stopping sight distance does not apply to cornering brake sight distance requirements. In this paper, the general values and limits of the curve stopping sight distance are presented.

  20. Evolution of the pulsar inclination angle in the wind braking model

    CERN Document Server

    Kou, F F; Wang, N

    2016-01-01

    In a plasma filled magnetosphere, in addition to providing a torque to brake down the pulsar, the magnetosphere will also generate a torque to align the pulsar magnetic and rotational axes. The evolution of pulsar inclination angle in the wind braking model is calculated. In the wind braking model, the oblique pulsar tends to align. The pulsar alignment will also affect the spin-down behavior. Braking index will increase firstly and then decrease as the pulsar evolving from the magneto-dipole radiation dominated case to the wind braking dominated case. Braking index may be larger than $3$ in the early time. And during the following long time, braking index will be always smaller than $3$. This can explain braking index observations of larger than $3$ and smaller than $3$. Besides, the pulsar will evolve downwards straightly to the death valley after pulsar death in the $P-\\dot{P}$ diagram. This may explain the observed maximum spinning period of pulsars. And the long-term evolution of pulsars in the wind brak...

  1. 30 CFR 75.523-3 - Automatic emergency-parking brakes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Automatic emergency-parking brakes. 75.523-3... SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Electrical Equipment-General § 75.523-3 Automatic emergency-parking brakes. (a) Except for personnel carriers, rubber-tired,...

  2. 49 CFR 571.135 - Standard No. 135; Light vehicle brake systems.

    Science.gov (United States)

    2010-10-01

    ... powered by an electric motor drawing current from rechargeable storage batteries, fuel cells, or other... charge batteries and components thereof. Electrically-actuated service brakes means service brakes that... lightly loaded vehicle weight, and, if an EV, with the propulsion batteries at a state of charge of...

  3. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK62 Federal Motor Vehicle Safety... that amended the Federal motor vehicle safety standard for air brake systems by requiring substantial... 37122) amending Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to...

  4. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... Administration 49 CFR Part 571 [Docket No. NHTSA-2009-0175] RIN 2127-AK84 Federal Motor Vehicle Safety Standards... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to require improved...

  5. INVESTIGATION OF ANTILOCK BRAKE SYSTEM EFFECT ON PASSENGER CAR BRAFKING EFFICIENCY

    Directory of Open Access Journals (Sweden)

    I. Davidenko

    2011-01-01

    Full Text Available It has been experimentally proved that in case of emergency braking the constant decelera-tion of passenger cars equipped by antilock brake system exceeds the tabulated statistical data by 7,7–17 % that is recommended to apply at technical expertise at traffic accident causes investigation.

  6. Brake wear from vehicles as an important source of diffuse copper pollution

    NARCIS (Netherlands)

    Hulskotte, J.H.J.; Gon, H.A.C.D. van der; Visschedijk, A.J.H.; Schaap, M.

    2007-01-01

    In this article we show that brake wear from road traffic vehicles is an important source of atmospheric (participate) copper concentrations in Europe. Consequently, brake wear also contributes significantly to deposition fluxes of copper to surface waters. We estimated the copper emission due to br

  7. Searchlights Illuminate Apollo 8 on Pad 39-A

    Science.gov (United States)

    1968-01-01

    Searchlights penetrate the darkness surrounding Apollo 8 on Pad 39-A at Kennedy Space Center. This mission was the first manned flight using the Saturn V. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

  8. Exploring the use of iPads in Danish schools

    DEFF Research Database (Denmark)

    2014-01-01

    million to develop the use of IT in elementary schools in Denmark. Since then, many municipalities have purchased iPads for schools for large sums. The existing literature, however, says very little about how these IT resources are being used or should be used in teaching. This paper contributes...

  9. Evaluation of the microdialysis technique in the dog fat pad

    DEFF Research Database (Denmark)

    Stallknecht, B; Madsen, J; Galbo, H

    1999-01-01

    In the present study the microdialysis technique was evaluated in an isolated autoperfused dog fat pad. Concentrations of glucose, lactate, and glycerol were measured in interstitial fluid by microdialysis and simultaneously in arterial and adipose venous plasma. Adipose tissue blood flow...

  10. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power efficien

  11. Fibroma of tendon sheath of the infrapatellar fat pad

    Energy Technology Data Exchange (ETDEWEB)

    Hur, J. [College of Medicine, State University of New York Health Science Center at Syracuse, Syracuse, NY (United States); Damron, T.A. [Department of Orthopedic Surgery, 550 Harrison Center, Syracuse, NY (United States); Vermont, A.I. [Department of Radiology, State University of New York Health Science Center at Syracuse, Syracuse, NY (United States); Mathur, S.C. [Department of Pathology, State University of New York Health Science Center at Syracuse, Syracuse, NY (United States)

    1999-07-01

    We report on a 13-year-old boy who was found to have a fibroma of the tendon sheath associated with the patellar tendon and within Hoffa`s fat pad of the knee. This benign tumor has never been described in this location previously. The MRI characteristics are correlated with the histologic findings. (orig.) With 2 figs., 18 refs.

  12. Control and sensor techniques for PAD servo motor drive

    DEFF Research Database (Denmark)

    Zsurzsan, Tiberiu-Gabriel; Zhang, Zhe; Andersen, Michael A. E.

    2015-01-01

    torque is 4 Nm, without any additional gearing. The whole motor is fully non-magnetic, enabling its use in applications where magnetic neutrality is of importance. The main challenges of the PAD are the hysteretic behavior of the ceramic actuators used and their highly capacitive nature. After...

  13. Teacher's Use of iPads in Higher Education

    Science.gov (United States)

    Churchill, Daniel; Wang, Tianchong

    2014-01-01

    Mobile devices (e.g. iPads or galaxy tab) are increasingly being used in educational contexts. There has been growing investment in higher education institutions in Hong Kong by the HKSAR Education Bureau in relation to educational uses of mobile technology. However, current research into educational applications of this technology is limited.…

  14. iPad Acceptance by English Learners in Saudi Arabia

    Science.gov (United States)

    Lawrence, Barry A. M.

    2016-01-01

    This study used the Unified Theory of Acceptance and Use of Technology (UTAUT; Venkatesh, Morris, Davis, & Davis, 2003) model to investigate factors predicting the acceptance of iPad tablets by learners of English as a foreign language (EFL) at a technical vocational college in Saudi Arabia. An online survey was conducted on 199 male learners,…

  15. Visual discrimination learning with an iPad-equipped apparatus.

    Science.gov (United States)

    Leising, Kenneth J; Wolf, Joshua E; Ruprecht, Chad M

    2013-02-01

    Visual discrimination tasks are commonly used to assess visual learning and memory in non-human animals. The current experiments explored the suitability of an iPad (Apple, Cupertino, California), as a low-cost alternative touchscreen for visual discrimination tasks. In Experiment 1, rats were trained with patterned black-and-white stimuli in a successive non-match to sample procedure. Rats successfully interacted with the iPad but failed to learn to withhold responding on trials in which the sample matched the comparison. Experiment 2 used the same patterned stimuli, but the procedure was simplified to a successive discrimination procedure and we explored the use of procedures known to facilitate discrimination learning. Rats that received training with differential outcomes and a differential reinforcement of other behavior schedule successfully acquired the task. In Experiment 3, the same rats were tested in a simultaneous discrimination task and we explored the use of a correction and non-correction method during acquisition. Rats that failed to learn the discrimination in the previous experiment, improved while trained with the correction method. These experiments support the use of the iPad in visual discrimination tasks and inform future studies investigating learning and memory within a touchscreen-equipped (iPad or other) apparatus.

  16. Response of tender cactus pads to Salmonella strains

    Science.gov (United States)

    Tender cactus pads (cladodes) or nopalitos (Opuntia ficus-indica L) are an important vegetable in Mexico. They are often pre-trimmed, cut and packaged, and while usually consumed cooked, they may also be eaten raw in salads. Salmonella is an enteropathogenic bacterium that can adapt to adverse envir...

  17. MAGNETIC BRAKING AND FIELD DISSIPATION IN THE PROTOSTELLAR ACCRETION PHASE

    Directory of Open Access Journals (Sweden)

    D. Galli

    2009-01-01

    Full Text Available We summarize recent theoretical work addressing the role of magnetic elds in the process of star formation. First, we concentrate on the efficiency of magnetic braking during cloud collapse and its consequences on the formation of centrifugally supported disks around young stars. Then, we relate this issue to the well-known magnetic ux problem of star formation, and we show that the introduction of non-ideal MHD e ects is a necessary step toward the development of self-consistent models for the collapse of molecular clouds and the formation and evolution of accretion disks around young stars.

  18. Taking the brakes off proppant-pack conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gulbis, J.; Hawkins, G.; King, M.; Pulsinelli, R.; Brown, E.; Elphick, J.

    1991-01-01

    Fracture stimulation treatments often fail to achieve predicted results because design data have not accounted for the downhole environment. Since 1986, the Dowell Schlumberger fracture conductivity laboratory has been carrying out realistic evaluations of proppants, fracturing fluids and additives. One element of this program has shown that viscous components of the treatment fluid remain in the proppant and significantly block flow of oil and gas. This knowledge has been applied to develop a new way of breaking down flow resistance, taking the brakes off proppant-pack conductivity. 13 figs., 4 ills., 1 tab., 12 refs.

  19. Modal reduction of brake squeal systems using complex interface modes

    Science.gov (United States)

    Besset, S.; Sinou, J.-J.

    2017-02-01

    This paper deals with a new efficient reduction method for predicting the stability analysis of a damped nonlinear brake system subjected to friction-induced vibration. The originality of the present work is to propose a generalized double modal synthesis method that combines a classical modal reduction and a condensation at the frictional interface by computing a reduced complex mode basis. Comparisons with the existing double modal synthesis reduction method are performed. It is demonstrated that the new suggested reduction technique is more efficient. It allows to provide satisfactory results with a small number of interfaces modes.

  20. Dynamic Braking System of a Tidal Generator: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Wright, Alan; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2016-08-01

    Renewable energy generation has experienced significant cost reductions during the past decades, and it has become more accepted by the global population. In the beginning, wind generation dominated the development and deployment of renewable energy; however, during recent decades, photovoltaic (PV) generation has grown at a very significant pace due to the tremendous decrease in the cost of PV modules. The focus on renewable energy generation has now expanded to include new types with promising future applications, such as river and tidal generation. The input water flow to these types of resources is more predictable than wind or solar generation. The data used in this paper is representative of a typical river or tidal generator. The analysis is based on a generator with a power rating of 40 kW. The tidal generator under consideration is driven by two sets of helical turbines connected to each side of the generator located in between the turbines. The generator is operated in variable speed, and it is controlled to maximize the energy harvested as well as the operation of the turbine generator. The electrical system consists of a three-phase permanent magnet generator connected to a three-phase passive rectifier. The output of the rectifier is connected to a DC-DC converter to match the rectifier output to the DC bus voltage of the DC-AC inverter. The three-phase inverter is connected to the grid, and it is controlled to provide a good interface with the grid. One important aspect of river and tidal generation is the braking mechanism. In a tidal generator, the braking mechanism is important to avoid a runaway condition in case the connection to the grid is lost when there is a fault in the lines. A runaway condition may lead to an overspeed condition and cause extreme stresses on the turbine blade structure and eventual disintegration of the mechanical structure. In this paper, the concept of the dynamic braking system is developed and investigated for normal

  1. 49 CFR 236.565 - Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading...

    Science.gov (United States)

    2010-10-01

    ... pneumatic brake-applying apparatus by double-heading cock; requirement. 236.565 Section 236.565... preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. Where provision is made for preventing the operation of the pneumatic brake-applying appartus of an...

  2. Auxiliary brakes for trucks : research into the behaviour of a tractor-semi-trailer combination during emergency breaking.

    NARCIS (Netherlands)

    Dijks, A. Blijswijk, W.A.M. van Genugten, J. van Meeke, G.J.M. & Schlösser, L.H.M.

    1976-01-01

    The purpose of the research was to obtain an insight into various secondary braking systems for goods vehicles. Practical tests were carried out with a tractor- semi-trailer combination. The performance of various split braking systems as well as spring brake actuators are shown. With nearly all of

  3. TID Test Results for 4th Generation iPad(TradeMark)

    Science.gov (United States)

    Guertin, S. M.; Allen, G. R.; McClure, S. S.; LaBel, K. A.

    2013-01-01

    TID testing of 4th generation iPads is reported. Of iPad subsystems, results indicate that the charging circuitry and display drivers fail at lowest TID levels. Details of construction are investigated for additional testing of components.

  4. Treating P.A.D. | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... turn Javascript on. Feature: Peripheral Artery Disease Treating P.A.D. Past Issues / Fall 2011 Table of ... provider to develop a supervised weight loss plan. P.A.D. Glossary Ankle-brachial index (ABI) A ...

  5. Development of brake system of railway vehicles for real-time HILS

    Science.gov (United States)

    Kim, Min-Soo; Park, Joon-Hyuk; Goo, Byeong-Choon

    2007-12-01

    Brake system of railway vehicles has a crucial role for the safety as well as riding quality of passengers. Its core technology for successful development of the brake system is to design of ECU (Electric Control Unit) containing antiskid control, brake blending control, load compensating control, and so on. Each development procedure of ECU involves a verifying test for each step and is completed by an evaluation test of the comprehensive performance verification for the overall systems. The development tool which is applied to this objective is the HILS (Hardware-In-the- Loop-Simulation). In order to design a controller, a good representative model of the system is needed. This paper describes the dynamic modeling of brake system of railway vehicle for HILS and analyzes some dynamic behavior under emergency braking force.

  6. Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

    Science.gov (United States)

    Byrdsong, T. A.

    1973-01-01

    An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

  7. Distribution and Dissipation of Braking Power of Wet Multidisc Brake%湿式多片制动器制动能的分配和耗散

    Institute of Scientific and Technical Information of China (English)

    阎清东; 宿新东

    2000-01-01

    研究湿式多片制动器制动过程制动能的分配和耗散,确定制动器的热负荷及摩擦偶件间热流分布的状况. 结合车辆的制动过程提出制动能四次分配的概念,利用有限元法计算制动能的三次、四次分配. 紧急制动中湿式多片制动器制动能的三次、四次分配主要与摩擦偶件的材料有关;持续制动中制动器吸收的能量主要由冷却润滑油带走. 为研究摩擦副的失效及摩擦材料的适用性提供了依据.%To study the distribution and dissipation of braking power of wet multidisc brake and determine thermal load and thermal flux distribution between mated discs, the concept of distributing brake power four times was put forward. The third and the fourth distribution of brake power were calculated by using finite element(FE) software ANSYS. The third and the fourth distribution of wet multidisc brake are mainly related to material characteristics of discs during emergency braking, while most of the braking power is carried off during continuous braking. Basis is provided for further analysis of disc failure and applicability of different friction materials.

  8. Arachnids secrete a fluid over their adhesive pads.

    Directory of Open Access Journals (Sweden)

    Anne M Peattie

    Full Text Available BACKGROUND: Many arachnids possess adhesive pads on their feet that help them climb smooth surfaces and capture prey. Spider and gecko adhesives have converged on a branched, hairy structure, which theoretically allows them to adhere solely by dry (solid-solid intermolecular interactions. Indeed, the consensus in the literature is that spiders and their smooth-padded relatives, the solifugids, adhere without the aid of a secretion. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated the adhesive contact zone of living spiders, solifugids and mites using interference reflection microscopy, which allows the detection of thin liquid films. Like insects, all the arachnids we studied left behind hydrophobic fluid footprints on glass (mean refractive index: 1.48-1.50; contact angle: 3.7-11.2°. Fluid was not always secreted continuously, suggesting that pads can function in both wet and dry modes. We measured the attachment forces of single adhesive setae from tarantulas (Grammostola rosea by attaching them to a bending beam with a known spring constant and filming the resulting deflection. Individual spider setae showed a lower static friction at rest (26%±2.8 SE of the peak friction than single gecko setae (Thecadactylus rapicauda; 96%±1.7 SE. This may be explained by the fact that spider setae continued to release fluid after isolation from the animal, lubricating the contact zone. SIGNIFICANCE: This finding implies that tarsal secretions occur within all major groups of terrestrial arthropods with adhesive pads. The presence of liquid in an adhesive contact zone has important consequences for attachment performance, improving adhesion to rough surfaces and introducing rate-dependent effects. Our results leave geckos and anoles as the only known representatives of truly dry adhesive pads in nature. Engineers seeking biological inspiration for synthetic adhesives should consider whether model species with fluid secretions are appropriate to their

  9. Functionally different pads on the same foot allow control of attachment: stick insects have load-sensitive "heel" pads for friction and shear-sensitive "toe" pads for adhesion.

    Directory of Open Access Journals (Sweden)

    David Labonte

    Full Text Available Stick insects (Carausius morosus have two distinct types of attachment pad per leg, tarsal "heel" pads (euplantulae and a pre-tarsal "toe" pad (arolium. Here we show that these two pad types are specialised for fundamentally different functions. When standing upright, stick insects rested on their proximal euplantulae, while arolia were the only pads in surface contact when hanging upside down. Single-pad force measurements showed that the adhesion of euplantulae was extremely small, but friction forces strongly increased with normal load and coefficients of friction were [Formula: see text] 1. The pre-tarsal arolium, in contrast, generated adhesion that strongly increased with pulling forces, allowing adhesion to be activated and deactivated by shear forces, which can be produced actively, or passively as a result of the insects' sprawled posture. The shear-sensitivity of the arolium was present even when corrected for contact area, and was independent of normal preloads covering nearly an order of magnitude. Attachment of both heel and toe pads is thus activated partly by the forces that arise passively in the situations in which they are used by the insects, ensuring safe attachment. Our results suggest that stick insect euplantulae are specialised "friction pads" that produce traction when pressed against the substrate, while arolia are "true" adhesive pads that stick to the substrate when activated by pulling forces.

  10. Study of heat transfer on front– and back-vented brake discs

    Directory of Open Access Journals (Sweden)

    Supachai Lakkam

    2013-12-01

    Full Text Available A brake disc plays an important role in the automotive industry since it concerns directly with safety. In order to develop proper heat ventilation a wide range of brake discs have been designed. Different types of physical brake disc geometries, as front- and back-vented brake discs, affect the heat ventilation directly. This is a vital factor of the brake’s capability. We recognized the importance of this circumstance and therefore attempted to create a test to investigate the temperature gradient of the brake disc in order to evaluate the coefficients of heat convection. The coefficients were modified by the change of temperature distribution in both brake discs under the forced heat convection in steady state conditions. However, the heat radiation value does not take into account that the heat convection is dominated by the physical geometry of the brake disc. To set up the experimental test for investigating the heat transfer by convection the JASO C406 standard is adopted. The experimental results in terms of heat convection coefficients are used in the numerical simulation via the finite element method in order to study the temperature diffusion and heat ventilation of front and back-vented brake discs. Conse-quently, the experimental results reveal that the overall heat convection coefficients of the front-vented brake disc are higher than these of the back-vented one. In other words the simulation yields that the front-vented brake disc allows stronger heat ventilation than its compared object, leading to larger temperature differences between outboard and inboard rotors, resulting in more thermal stress. This makes it more susceptible to be damaged during operation.

  11. Direct interaction between the Arabidopsis disease resistance signaling proteins, EDS1 and PAD4.

    Science.gov (United States)

    Feys, B J; Moisan, L J; Newman, M A; Parker, J E

    2001-10-01

    The Arabidopsis EDS1 and PAD4 genes encode lipase-like proteins that function in resistance (R) gene-mediated and basal plant disease resistance. Phenotypic analysis of eds1 and pad4 null mutants shows that EDS1 and PAD4 are required for resistance conditioned by the same spectrum of R genes but fulfil distinct roles within the defence pathway. EDS1 is essential for elaboration of the plant hypersensitive response, whereas EDS1 and PAD4 are both required for accumulation of the plant defence-potentiating molecule, salicylic acid. EDS1 is necessary for pathogen-induced PAD4 mRNA accumulation, whereas mutations in PAD4 or depletion of salicylic acid only partially compromise EDS1 expression. Yeast two-hybrid analysis reveals that EDS1 can dimerize and interact with PAD4. However, EDS1 dimerization is mediated by different domains to those involved in EDS1-PAD4 association. Co-immunoprecipitation experiments show that EDS1 and PAD4 proteins interact in healthy and pathogen-challenged plant cells. We propose two functions for EDS1. The first is required early in plant defence, independently of PAD4. The second recruits PAD4 in the amplification of defences, possibly by direct EDS1-PAD4 association.

  12. Internal strain estimation for quantification of human heel pad elastic modulus: A phantom study

    DEFF Research Database (Denmark)

    Holst, Karen; Liebgott, Hervé; Wilhjelm, Jens E.;

    2013-01-01

    Shock absorption is the most important function of the human heel pad. However, changes in heel pad elasticity, as seen in e.g. long-distance runners, diabetes patients, and victims of Falanga torture are affecting this function, often in a painful manner. Assessment of heel pad elasticity...

  13. Use of Doceri Software for iPad in Online Delivery of Chemistry Content

    Science.gov (United States)

    Silverberg, Lee J.; Tierney, John; Bodek, Matthew J.

    2014-01-01

    Doceri software for iPad is useful for both synchronous online and asynchronous online delivery of chemistry course content. Using the Doceri wireless connection between the iPad and a personal computer that is running Adobe Connect, online synchronous instruction can be accomplished in which drawings can be completed by hand on the iPad. For…

  14. Digital Sliding Mode Control of Anti-Lock Braking System

    Directory of Open Access Journals (Sweden)

    MITIC, D. B.

    2013-02-01

    Full Text Available The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

  15. FES-Assisted Walking with Spring Brake Orthosis: Simulation Studies

    Directory of Open Access Journals (Sweden)

    R. Jailani

    2011-01-01

    Full Text Available This paper presents a simulation of bipedal locomotion to generate stimulation pulses for activating muscles for paraplegic walking with wheel walker using functional electrical stimulation (FES with spring brake orthosis (SBO. A new methodology for paraplegic gait, based on exploiting natural dynamics of human gait, is introduced. The work is a first effort towards restoring natural like swing phase in paraplegic gait through a new hybrid orthosis, referred to as spring brake orthosis (SBO. This mechanism simplifies the control task and results in smooth motion and more-natural like trajectory produced by the flexion reflex for gait in spinal cord injured subjects. SBO can eliminate reliance on the withdrawal reflex and foot-ground clearance without extra upper body effort. The stored energy in the spring of SBO is used to replace stimulation pulses in knee flexion and reduce total required torque for the paraplegic walking with wheel walker. The study is carried out with a model of humanoid with wheel walker using the Visual Nastran (Vn4D dynamic simulation software. Stimulated muscle model of quadriceps is developed for knee extension. Fuzzy logic control (FLC is developed in Matlab/Simulink to regulate the muscle stimulation pulse-width required to drive FES-assisted walking gait and the computed motion is visualised in graphic animation from Vn4D. The simulation results show that SBO can be successfully used with FES for paraplegic walking with wheel walker with all the advantages discussed over the current hybrid orthoses available.

  16. Structure Analysis at the Micro Iron Pour at Gray Brake

    Directory of Open Access Journals (Sweden)

    Melya D. Sebayang

    2012-01-01

    Full Text Available The use of gray cast iron brake drum as the material is the most appropriate choice, because it has properties which have good heat conductivity, hardness, toughness, good friction properties and the ability to absorb vibration. The purpose of this study to determine the ratio of the microstructure on both original material drum that is new and original drum ex-wear. With the aim of analysis is expected to be used as basis in planning the development of better vehicle brakes. Of all the test results it can be mentioned chemical composition of test results with the main alloying elements, to drum new original: C 4:13%, 2:51% Si, 0.15% S, 0.65% Mn, 0.0054% P, and the original drum ex-wear: C 4:13%, 2:17% Si, 0.15% S, 0.53% Mn, 0.0054% P. So the comparison of properties of the resulting structure after the testing process on each drum is the hardness and resistance to wear and tear on a new original drum better when compared with the original drum ex-wear.

  17. iPad for the Older and Wiser Get Up and Running Safely and Quickly with the Apple iPad

    CERN Document Server

    McManus, Sean

    2011-01-01

    Easy-to-follow, friendly advice on using the iPad 2 This heavily illustrated, approachable guide for the anyone over 50 provides a solid resource for learning how to use the iPad in everyday situations. Veteran author and technology expert Sean McManus clearly explains how to use the iPad to send e-mails, listen to music, watch movies, and play games. Detailed coverage walks you step by step through setting up and registering your iPad, connecting to the Internet, syncing your iPad to other devices, and much more. The iPad is an ideal companion for making your life easier, and this friendly gu

  18. Optimal design of disc-type magneto-rheological brake for mid-sized motorcycle: experimental evaluation

    Science.gov (United States)

    Sohn, Jung Woo; Jeon, Juncheol; Nguyen, Quoc Hung; Choi, Seung-Bok

    2015-08-01

    In this paper, a disc-type magneto-rheological (MR) brake is designed for a mid-sized motorcycle and its performance is experimentally evaluated. The proposed MR brake consists of an outer housing, a rotating disc immersed in MR fluid, and a copper wire coiled around a bobbin to generate a magnetic field. The structural configuration of the MR brake is first presented with consideration of the installation space for the conventional hydraulic brake of a mid-sized motorcycle. The design parameters of the proposed MR brake are optimized to satisfy design requirements such as the braking torque, total mass of the MR brake, and cruising temperature caused by the magnetic-field friction of the MR fluid. In the optimization procedure, the braking torque is calculated based on the Herschel-Bulkley rheological model, which predicts MR fluid behavior well at high shear rate. An optimization tool based on finite element analysis is used to obtain the optimized dimensions of the MR brake. After manufacturing the MR brake, mechanical performances regarding the response time, braking torque and cruising temperature are experimentally evaluated.

  19. Performance Evaluation of an Anti-Lock Braking System for Electric Vehicles with a Fuzzy Sliding Mode Controller

    Directory of Open Access Journals (Sweden)

    Jingang Guo

    2014-10-01

    Full Text Available Traditional friction braking torque and motor braking torque can be used in braking for electric vehicles (EVs. A sliding mode controller (SMC based on the exponential reaching law for the anti-lock braking system (ABS is developed to maintain the optimal slip value. Parameter optimizing is applied to the reaching law by fuzzy logic control (FLC. A regenerative braking algorithm, in which the motor torque is taken full advantage of, is adopted to distribute the braking force between the motor braking and the hydraulic braking. Simulations were carried out with Matlab/Simulink. By comparing with a conventional Bang-bang ABS controller, braking stability and passenger comfort is improved with the proposed SMC controller, and the chatting phenomenon is reduced effectively with the parameter optimizing by FLC. With the increasing proportion of the motor braking torque, the tracking of the slip ratio is more rapid and accurate. Furthermore, the braking distance is shortened and the conversion energy is enhanced.

  20. Corrosion investigation of material combinations in a mobile phone dome-key pad system

    DEFF Research Database (Denmark)

    Ambat, Rajan; Møller, Per

    2007-01-01

    Mobile phone dome-key pad system is the device that connects the phone keys to the printed circuit board (PCB). The material combination for a typical dome-key pad system is Ag/AISI 202 steel for the dome and Au/Ni/Cu for the key pad. Under humid conditions dome-key pad system is susceptible...... microstructural studies, polarization measurements using microelectrochemical technique, salt spray testing, and corrosion morphology analysis. The immersion Au layer on pads showed pores, and rolled bonded silver layer on dome had cracks and kinks. The difference in electrochemical behaviour of the metallic...

  1. Multi-objective optimization of the control strategy of electric vehicle electro-hydraulic composite braking system with genetic algorithm

    Directory of Open Access Journals (Sweden)

    Zhang Fengjiao

    2015-03-01

    Full Text Available Optimization of the control strategy plays an important role in improving the performance of electric vehicles. In order to improve the braking stability and recover the braking energy, a multi-objective genetic algorithm is applied to optimize the key parameters in the control strategy of electric vehicle electro-hydraulic composite braking system. Various limitations are considered in the optimization process, and the optimization results are verified by a software simulation platform of electric vehicle regenerative braking system in typical brake conditions. The results show that optimization objectives achieved a good astringency, and the optimized control strategy can increase the brake energy recovery effectively under the condition of ensuring the braking stability.

  2. Toxic effects of brake wear particles on epithelial lung cells in vitro

    Directory of Open Access Journals (Sweden)

    Perrenoud Alain

    2009-11-01

    Full Text Available Abstract Background Fine particulate matter originating from traffic correlates with increased morbidity and mortality. An important source of traffic particles is brake wear of cars which contributes up to 20% of the total traffic emissions. The aim of this study was to evaluate potential toxicological effects of human epithelial lung cells exposed to freshly generated brake wear particles. Results An exposure box was mounted around a car's braking system. Lung cells cultured at the air-liquid interface were then exposed to particles emitted from two typical braking behaviours („full stop“ and „normal deceleration“. The particle size distribution as well as the brake emission components like metals and carbons was measured on-line, and the particles deposited on grids for transmission electron microscopy were counted. The tight junction arrangement was observed by laser scanning microscopy. Cellular responses were assessed by measurement of lactate dehydrogenase (cytotoxicity, by investigating the production of reactive oxidative species and the release of the pro-inflammatory mediator interleukin-8. The tight junction protein occludin density decreased significantly (p Conclusion These findings suggest that the metals on brake wear particles damage tight junctions with a mechanism involving oxidative stress. Brake wear particles also increase pro-inflammatory responses. However, this might be due to another mechanism than via oxidative stress.

  3. A method to model anticipatory postural control in driver braking events.

    Science.gov (United States)

    Östh, Jonas; Eliasson, Erik; Happee, Riender; Brolin, Karin

    2014-09-01

    Human body models (HBMs) for vehicle occupant simulations have recently been extended with active muscles and postural control strategies. Feedback control has been used to model occupant responses to autonomous braking interventions. However, driver postural responses during driver initiated braking differ greatly from autonomous braking. In the present study, an anticipatory postural response was hypothesized, modelled in a whole-body HBM with feedback controlled muscles, and validated using existing volunteer data. The anticipatory response was modelled as a time dependent change in the reference value for the feedback controllers, which generates correcting moments to counteract the braking deceleration. The results showed that, in 11 m/s(2) driver braking simulations, including the anticipatory postural response reduced the peak forward displacement of the head by 100mm, of the shoulder by 30 mm, while the peak head flexion rotation was reduced by 18°. The HBM kinematic response was within a one standard deviation corridor of corresponding test data from volunteers performing maximum braking. It was concluded that the hypothesized anticipatory responses can be modelled by changing the reference positions of the individual joint feedback controllers that regulate muscle activation levels. The addition of anticipatory postural control muscle activations appears to explain the difference in occupant kinematics between driver and autonomous braking. This method of modelling postural reactions can be applied to the simulation of other driver voluntary actions, such as emergency avoidance by steering.

  4. Experimental Method for Analyzing Friction Phenomenon Related to Drum Brake Squeal

    Directory of Open Access Journals (Sweden)

    J. GLIŠOVIĆ

    2010-12-01

    Full Text Available Automobile brakes have been intensively developed during past few decades, but the maximum motor’s power, that should amortized in vehicle brakes, has been significantly increased also. Most of the kinetic energy of the moving vehicles is transforming into heat through friction. But the small part of kinetic energy transforms into sound pressure and makes noise. Low frequency squeal of drum brakes is very intense and can lead to customers’ complain. The interaction between the brake system and the vehicle framework and suspension is often very substantial during occurrence of brake noise. Unfortunately, to solve this type of squeal problem is also difficult because of the large number of components involved. The other cause is attributed to self-excited vibration that is induced when the friction material has a negative slope in relation to the relative velocity. This paper illustrates an approach to experimental studies of drum brakes in road conditions in order to monitor changes in the coefficient of friction that can generate drum brake squeal at low frequencies.

  5. Evaluation the course of the vehicle braking process in case of hydraulic circuit malfunction

    Science.gov (United States)

    Szczypiński-Sala, W.; Lubas, J.

    2016-09-01

    In the paper, the results of the research were discussed, the aim of which was the evaluation of the vehicle braking performance efficiency and the course of this process with regard to the dysfunction which may occur in braking hydraulic circuit. As part of the research, on-road tests were conducted. During the research, the delay of the vehicle when braking was measured with the use of the set of sensors placed in the parallel and the perpendicular axis of the vehicle. All the tests were conducted on the same flat section of asphalt road with wet surface. Conditions of diminished tire-to-road adhesion were chosen in order to force the activity of anti-lock braking system. The research was conducted comparatively for the vehicle with acting anti-lock braking system and subsequently for the vehicle without the system. In both cases, there was a subsequent evaluation of the course of braking with efficient braking system and with the dysfunction of hydraulic circuit.

  6. Plugging Braking of Two-PMSM Drive in Subway Applications with Fault-Tolerant Operation

    Directory of Open Access Journals (Sweden)

    Adel A. obed

    2016-06-01

    Full Text Available The Permanent Magnet Synchronous Motor (PMSM is commonly used as traction motors in the electric traction applications such as in subway train. The subway train is better transport vehicle due to its advantages of security, economic, health and friendly with nature. Braking is defined as removal of the kinetic energy stored in moving parts of machine. The plugging braking is the best braking offered and has the shortest time to stop. The subway train is a heavy machine and has a very high moment of inertia requiring a high braking torque to stop. The plugging braking is an effective method to provide a fast stop to the train. In this paper plugging braking system of the PMSM used in the subway train in normal and fault-tolerant operation is made. The model of the PMSM, three-phase Voltage Source Inverter (VSI controlled using Space Vector Pulse Width Modulation technique (SVPWM, Field Oriented Control method (FOC for independent control of two identical PMSMs and fault-tolerant operation is presented. Simulink model of the plugging braking system of PMSM in normal and fault tolerant operation is proposed using Matlab/Simulink software. Simulation results for different cases are given.

  7. Study on Parameter Optimization Design of Drum Brake Based on Hybrid Cellular Multiobjective Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2012-01-01

    Full Text Available In consideration of the significant role the brake plays in ensuring the fast and safe running of vehicles, and since the present parameter optimization design models of brake are far from the practical application, this paper proposes a multiobjective optimization model of drum brake, aiming at maximizing the braking efficiency and minimizing the volume and temperature rise of drum brake. As the commonly used optimization algorithms are of some deficiency, we present a differential evolution cellular multiobjective genetic algorithm (DECell by introducing differential evolution strategy into the canonical cellular genetic algorithm for tackling this problem. For DECell, the gained Pareto front could be as close as possible to the exact Pareto front, and also the diversity of nondominated individuals could be better maintained. The experiments on the test functions reveal that DECell is of good performance in solving high-dimension nonlinear multiobjective problems. And the results of optimizing the new brake model indicate that DECell obviously outperforms the compared popular algorithm NSGA-II concerning the number of obtained brake design parameter sets, the speed, and stability for finding them.

  8. Office for iPad and Mac for dummies

    CERN Document Server

    Weverka, Peter

    2015-01-01

    The easy way to work with Office on your iPad or Mac Are you a Mac user who isn't accustomed to working with Microsoft Office? Consider this friendly guide your go-to reference! Written in plain English and packed with easy-to-follow, step-by-step instructions, Office for iPad and Mac For Dummies walks you through every facet of Office, from installing the software and opening files to working with Word, Excel, PowerPoint, and Outlook-and beyond. Plus, you'll discover how to manage files, share content and collaborate online through social media, and find help when you need it. Two things a

  9. View and Manage Your Photos on the iPad

    CERN Document Server

    Biersdorfer, J

    2010-01-01

    One of the iPad's big pluses is its beautiful, high-resolution display. That makes it a perfect way to stroll down memory lane-from the comfort of your armchair. View and Manage Your Photos on the iPad: The Mini Missing Manual shows you how to import, organize, and enjoy your photos using clear, jargon-free explanations and step-by-step instructions. You'll learn to create slideshows complete with your own soundtrack and transitions, connect your tablet to a big-screen TV so you can gather the family around, turn your slab into a digital picture frame (a great idea when you recharge your 'Pa

  10. Pad A Main Flame Deflector Sensor Data and Evaluation

    Science.gov (United States)

    Parlier, Christopher R.

    2011-01-01

    Space shuttle launch pads use flame deflectors beneath the vehicle to channel hot gases away from the vehicle. Pad 39 A at the Kennedy Space Center uses a steel structure coated with refractory concrete. The solid rocket booster plume is comprised of gas and molten alumina oxide particles that erodes the refractory concrete. During the beginning of the shuttle program the loads for this system were never validated with a high level of confidence. This paper presents a representation of the instrumentation data collected and follow on materials science evaluation of the materials exposed to the SRB plume. Data collected during STS-133 and STS-134 will be presented that support the evaluation of the components exposed to the SRB plume.

  11. Simulative Design of Pad Structure for High Density Electronic Interconnection

    Institute of Scientific and Technical Information of China (English)

    Mingyu LI; Chunqing WANG

    2005-01-01

    Solder bridge is a serious defect of solder joints in ultrafine pitch electronic device assemblies. Generation of the solder bridge is closely related to forming process of the solder joints. A three-dimensional model to simulate the formation of the solder bridge of QFP256 (quad flat packaging with 256 leads) is established and numerically calculated to predict the formation shape of the solder joints using surface evolver program. Based on the model, influence of structure of pads printed on circuit board on solder bridging is investigated. The results show that there is a critical solder volume Vc for solder joints to avoid solder bridging, and parameters of the pad size influence the critical solder volume.

  12. Flexible bending of aluminum profiles with polyurethane pad

    Institute of Scientific and Technical Information of China (English)

    HE Zhu-bin; LIU Gang; WANG Zhong-ren

    2006-01-01

    The high flexibility of profile bending with hyperelastic pad enables it to be a promising method for small lot or single part production, especially for space frame and roof-rail parts in automotive and aerospace industries. Bending of two aluminum profiles with different sections was carried out to investigate the effect of main process parameters on the bending process. Results show that the shape of the cross-section and its relative thickness and section modulus in bending are the main factors that determine the bending properties of the profiles. Roller stroke, properties of polyurethane pad and constraints on profiles are key factors that determine the bending radius and section deformation of bent profiles. Failures and quality problems met in experiments were also analyzed.

  13. DETERMINATION OF BRAKING OPTIMAL MODE OF CONTROLLED CUT OF DESIGN GROUP

    Directory of Open Access Journals (Sweden)

    A. S. Dorosh

    2015-06-01

    Full Text Available Purpose. The application of automation systems of breaking up process on the gravity hump is the efficiency improvement of their operation, absolute provision of trains breaking up safety demands, as well as improvement of hump staff working conditions. One of the main tasks of the indicated systems is the assurance of cuts reliable separation at all elements of their rolling route to the classification track. This task is a sophisticated optimization problem and has not received a final decision. Therefore, the task of determining the cuts braking mode is quite relevant. The purpose of this research is to find the optimal braking mode of control cut of design group. Methodology. In order to achieve the purpose is offered to use the direct search methods in the work, namely the Box complex method. This method does not require smoothness of the objective function, takes into account its limitations and does not require calculation of the function derivatives, and uses only its value. Findings. Using the Box method was developed iterative procedure for determining the control cut optimal braking mode of design group. The procedure maximizes the smallest controlled time interval in the group. To evaluate the effectiveness of designed procedure the series of simulation experiments of determining the control cut braking mode of design group was performed. The results confirmed the efficiency of the developed optimization procedure. Originality. The author formalized the task of optimizing control cut braking mode of design group, taking into account the cuts separation of design group at all elements (switches, retarders during cuts rolling to the classification track. The problem of determining the optimal control cut braking mode of design group was solved. The developed braking mode ensures cuts reliable separation of the group not only at the switches but at the retarders of brake position. Practical value. The developed procedure can be

  14. Detection of visually unrecognizable braking tracks using Laser-Induced Breakdown Spectroscopy, a feasibility study

    Science.gov (United States)

    Prochazka, David; Bilík, Martin; Prochazková, Petra; Brada, Michal; Klus, Jakub; Pořízka, Pavel; Novotný, Jan; Novotný, Karel; Ticová, Barbora; Bradáč, Albert; Semela, Marek; Kaiser, Jozef

    2016-04-01

    Identification of the position, length and mainly beginning of a braking track has proven to be essential for determination of causes of a road traffic accident. With the introduction of modern safety braking systems and assistance systems such as the Anti-lock Braking System (ABS) or Electronic Stability Control (ESC), the visual identification of braking tracks that has been used up until the present is proving to be rather complicated or even impossible. This paper focuses on identification of braking tracks using a spectrochemical analysis of the road surface. Laser-Induced Breakdown Spectroscopy (LIBS) was selected as a method suitable for fast in-situ element detection. In the course of detailed observations of braking tracks it was determined that they consist of small particles of tire treads that are caught in intrusions in the road surface. As regards detection of the "dust" resulting from wear and tear of tire treads in the environment, organic zinc was selected as the identification element in the past. The content of zinc in tire treads has been seen to differ with regard to various sources and tire types; however, the arithmetic mean and modus of these values are approximately 1% by weight. For in-situ measurements of actual braking tracks a mobile LIBS device equipped with a special module was used. Several measurements were performed for 3 different cars and tire types respectively which slowed down with full braking power. Moreover, the influence of different initial speed, vehicle mass and braking track length on detected signal is discussed here.

  15. Orion Pad Abort 1 Flight Test - Ground and Flight Operations

    Science.gov (United States)

    Hackenbergy, Davis L.; Hicks, Wayne

    2011-01-01

    This paper discusses the ground and flight operations aspects to the Pad Abort 1 launch. The paper details the processes used to plan all operations. The paper then discussions the difficulties of integration and testing, while detailing some of the lessons learned throughout the entire launch campaign. Flight operational aspects of the launc are covered in order to provide the listener with the full suite of operational issues encountered in preparation for the first flight test of the Orion Launch Abort System.

  16. A simple guide to iPad 2

    CERN Document Server

    Woodward, C Michael

    2011-01-01

    From built-in apps such as iPod, iTunes, iBooks, Maps, Photo Booth, Facetime, and Spotlight Search to the coolest, most entertaining, and most useful apps on the App Store, this guide helps readers take the maximum advantage of their iPad and set it up to meet their needs and interests. The book also discusses how to take pictures and videos, maximize power usage, and connect to the internet using both 3G and wireless.

  17. ClimatePad: Enabling public exploration of climate data

    Science.gov (United States)

    Walsh, J. E.; Chapman, W. L.

    2012-12-01

    Informal learners interested in climate issues can find a wealth of information in the print and online media related to climate and climate change. Throughout these resources, the equal use of generic terms like 'global warming' and 'climate change' suggest a level of nuance in the science that is not easy to convey in this conventional media. Perhaps more than any other discipline, climate literacy has the most potential to be enhanced via the process of cognitive construction and reconstruction, rather than simple transmission of knowledge. Constructionism suggests that meaningful learning happens most effectively if the learner is actively engaged in constructing a product in the real world rather than absorbing information passively. Recent technological innovations have introduced mobile computing devices with sufficient power to do serious data analysis. The potential of these devices to augment climate literacy by turning citizens into scientists has yet to be exploited. We introduce ClimatePad, an iPad application that permits students and public to actively browse climate datasets, construct trends, plot time series, create composite differences and view animations of real-world climate data. Interactions with the ClimatePad permits varying the starting and ending dates of trends and differences. Climate analysis maps and animations can be customized with different color palettes, enticing the user to delve into and absorb the subtleties of the regional and temporal variations of the recent climate record. Finally, user-generated climate visualizations created with ClimatePad can be emailed to friends and shared via Facebook, entraining even more active learners.

  18. Finger pad friction and its role in grip and touch

    Science.gov (United States)

    Adams, Michael J.; Johnson, Simon A.; Lefèvre, Philippe; Lévesque, Vincent; Hayward, Vincent; André, Thibaut; Thonnard, Jean-Louis

    2013-01-01

    Many aspects of both grip function and tactile perception depend on complex frictional interactions occurring in the contact zone of the finger pad, which is the subject of the current review. While it is well established that friction plays a crucial role in grip function, its exact contribution for discriminatory touch involving the sliding of a finger pad is more elusive. For texture discrimination, it is clear that vibrotaction plays an important role in the discriminatory mechanisms. Among other factors, friction impacts the nature of the vibrations generated by the relative movement of the fingertip skin against a probed object. Friction also has a major influence on the perceived tactile pleasantness of a surface. The contact mechanics of a finger pad is governed by the fingerprint ridges and the sweat that is exuded from pores located on these ridges. Counterintuitively, the coefficient of friction can increase by an order of magnitude in a period of tens of seconds when in contact with an impermeably smooth surface, such as glass. In contrast, the value will decrease for a porous surface, such as paper. The increase in friction is attributed to an occlusion mechanism and can be described by first-order kinetics. Surprisingly, the sensitivity of the coefficient of friction to the normal load and sliding velocity is comparatively of second order, yet these dependencies provide the main basis of theoretical models which, to-date, largely ignore the time evolution of the frictional dynamics. One well-known effect on taction is the possibility of inducing stick–slip if the friction decreases with increasing sliding velocity. Moreover, the initial slip of a finger pad occurs by the propagation of an annulus of failure from the perimeter of the contact zone and this phenomenon could be important in tactile perception and grip function. PMID:23256185

  19. Steroid-induced Kager's fat pad atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Taneja, Atul K. [Hospital Israelita Albert Einstein, Musculoskeletal Radiology Division, Imaging Department, Sao Paulo (Brazil); Musculoskeletal Imaging, Diagnostic Center, Hospital do Coracao (HCor) and Teleimagem, Sao Paulo, SP (Brazil); Santos, Durval C.B. [Hospital Israelita Albert Einstein, Musculoskeletal Radiology Division, Imaging Department, Sao Paulo (Brazil)

    2014-08-15

    We report a rare case of Kager's fat pad atrophy and fibrosis in a 60-year-old woman 1 year after a steroid injection for Achilles tendinopathy. There are few published reports of steroid-induced atrophy affecting deeper layers of fat tissue. To our knowledge, this case report is the first to illustrate its features using magnetic resonance imaging. A review of the scientific literature is also presented. (orig.)

  20. 汽车刹车片用复合型金属陶瓷涂层制备及性能研究%Preparation and Property Study of Composite Cermet Coating Used in Automobile Brake Shoes

    Institute of Scientific and Technical Information of China (English)

    侯占祥; 靳清

    2012-01-01

    The Preparation process and application property of composite cermet coating used in automobile brake shoes were studied in this paper. A new type of WC-CoCr10/4 cermet powder that joint R&D with a domestic research institute were selected and the optimized HVOF spraying process were uesd to made coating directly on the braking disc. The study found that, using the composite cermet coating as a braking disc can make its tensile strength up to 75 Mpa above with brake pads, Microhardness can reach 1300 (HV0.3), at the same time, the coating has compact structure and low porosity, which not only improving the wearing resistance and significant extending the life of brake shoes, but also reduce the cost of production,. And the coatings fully meet the practical use requirements and have a broad application prospect.%本文进行了将复合型金属陶瓷涂层用于汽车刹车片的制备工艺与应用性能的初步研究。选用与国内某研究机构联合研制的新型WC—CoCr10/4金属陶瓷粉体作为刹车片材料并采用优化后的HVOF超音速火焰喷涂工艺直接在制动盘上制备,经研究发现,采用该复合涂层作为刹车片可以使其与制动盘之间的拉伸结合强度达到75Mpa以上,显微硬度可达HV0.31300,同时该涂层具有组织致密、孔隙率低等特点,在提高刹车片耐磨性、显著延长使用寿命的同时也降低了生产成本,完全满足实际使用需求,具有广阔的应用前景。