WorldWideScience

Sample records for bolted joints

  1. Decision Fusion System for Bolted Joint Monitoring

    Directory of Open Access Journals (Sweden)

    Dong Liang

    2015-01-01

    Full Text Available Bolted joint is widely used in mechanical and architectural structures, such as machine tools, industrial robots, transport machines, power plants, aviation stiffened plate, bridges, and steel towers. The bolt loosening induced by flight load and environment factor can cause joint failure leading to a disastrous accident. Hence, structural health monitoring is critical for the bolted joint detection. In order to realize a real-time and convenient monitoring and satisfy the requirement of advanced maintenance of the structure, this paper proposes an intelligent bolted joint failure monitoring approach using a developed decision fusion system integrated with Lamb wave propagation based actuator-sensor monitoring method. Firstly, the basic knowledge of decision fusion and classifier selection techniques is briefly introduced. Then, a developed decision fusion system is presented. Finally, three fusion algorithms, which consist of majority voting, Bayesian belief, and multiagent method, are adopted for comparison in a real-world monitoring experiment for the large aviation aluminum plate. Based on the results shown in the experiment, a big potential in real-time application is presented that the method can accurately and rapidly identify the bolt loosening by analyzing the acquired strain signal using proposed decision fusion system.

  2. Failure analyses of composite bolted joints

    Science.gov (United States)

    Wilson, D. W.; Gillespie, J. W.; York, J. L.; Pipes, R. B.

    1980-01-01

    The complex failure behavior exhibited by bolted joints of graphite epoxy (Hercules AS/3501) was investigated for the net tension, bearing and shearout failure modes using combined analytical and experimental techniques. Plane stress, linear elastic, finite element methods were employed to determine the two dimensional state of stress resulting from a loaded hole in a finite width, semiinfinite strip. The stresses predicted by the finite element method were verified by experiment to lend credence to the analysis. The influence of joint geometric parameters on the state of stress and resultant strength of the joint was also studied. The resulting functional relationships found to exist between bolted joint strength and the geometric parameters, were applied in the formulation of semiempirical strength models for the basic failure modes. A point stress failure criterion was successfully applied as the failure criterion for the net tension and shearout failure modes.

  3. Beam to Column Timber Joints with Pretensioned Bolts

    Directory of Open Access Journals (Sweden)

    Hayashikawa T.

    2011-01-01

    Full Text Available The effects of pretension in bolts on hysteretic response of timber joints exposed to a bending had been reported by the authors, but the cyclic tests were carried out at small displacement level which might not be applicable for earthquake-resistance design. In this study, similar cyclic tests but at large displacement levels were conducted. Beam to column timber joints with steel side plates were fabricated and continuously loaded until failure. At connection, the bolts were pretension in four different magnitudes: 0 kN, 5 kN, 10 kN and 15 kN. The results showed that frictional action between the steel side plates and wood member as a result of bolt pretensioning significantly increased the (frictional hysteretic damping and the equivalent viscous damping ratio. It is obvious from the test results that the pretension force in bolts has no influence on the maximum joint resistance but decreases the joint rotational deformation.

  4. FEM modelling of fatigue loaded bolted flange joints

    Directory of Open Access Journals (Sweden)

    T. Smolnicki

    2007-05-01

    Full Text Available Purpose: The main purpose of this paper is to describe the modelling of large flexible objects in which bolted joints are used and also to present a new FEM calculation methodology of these objects.Design/methodology/approach: In bolted flange joints of flexible constructional elements, bolts are subject not only to tension and torsion but also to bending. Identification of straining of each bolt is only possible by means of numerical methods e.g. the finite element method FEM. In case of large objects, the calculation problem is faithful projection of the phenomena taking place in direct zone of the contact of screw-nut pair. The application of global equivalent models of the whole joint is necessary, to make it possible to precisely determine internal loads in individual bolts and then local models to determine stress fields necessary to assign durability.Calculation methodology based on the construction of two coherent models has been described: global - of an entire flange joint, and local - of a single bolt joint.Findings: The elaborated methodology was applied to estimate the flange joint in the heat exchanger with rotating heating surfaces that was subject to damage. The causes of damage of flange joint were found.Practical implications: Used methodology of FEM modelling of bolted flange joints based on two coherent models may be applied for different similar objects. The paper provides detailed description of methodology steps.Originality/value: The described methodology may be successfully applied to the analysis of large objects, however, significant geometric features with dimensions small in relation to dimensions of the whole object. Thanks to the application of two coherent models, it is possible to reflect all essential phenomena in the FEM model, both in the global scale - of the entire object, and local – a significant fragment of the joint.

  5. Guideline for bolted joint design and analysis : version 1.0.

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Kevin H.; Morrow, Charles W.; Durbin, Samuel; Baca, Allen

    2008-01-01

    This document provides general guidance for the design and analysis of bolted joint connections. An overview of the current methods used to analyze bolted joint connections is given. Several methods for the design and analysis of bolted joint connections are presented. Guidance is provided for general bolted joint design, computation of preload uncertainty and preload loss, and the calculation of the bolted joint factor of safety. Axial loads, shear loads, thermal loads, and thread tear out are used in factor of safety calculations. Additionally, limited guidance is provided for fatigue considerations. An overview of an associated Mathcad{copyright} Worksheet containing all bolted joint design formulae presented is also provided.

  6. Shear fracture of jointed steel plates of bolted joints under impact load

    Science.gov (United States)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

    2013-07-01

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

  7. Bearing Stresses in Bolted Composite Joints with Different Contact Interactions.

    Directory of Open Access Journals (Sweden)

    Hilton Ahmad

    2016-04-01

    Full Text Available In a bolted joint, it has been shown to be better to model the real contact between bolt and hole than to fix the boundary of the hole edge, a practice used by most previous researchers. Master-slave interaction was implemented in ABAQUS to simulate full contact conditions. Stress distributions were plotted along net-tension plane and hole boundary. Due to geometric non-linearity, the clearance and friction coefficients used substantially effected the maximum stress on hole boundary as shown using the benchmarking work of Eriksson. A physically-based constitutive model used is based on state-of-the art fracture mechanics was used for bolted joint strength prediction. Idealized models from Hollmann were remodelled both by fixing the hole boundary (following the original author and by implementing full contact condition using CZM and XFEM. The physically-based constitutive law used independently measured of unnotched strength and fracture energy parameter for crack opening, which is calibrated from available literatures (known as apparent fracture energy. Good correlation with experimental results was found when using the real contact condition.

  8. Experimental study of friction in aluminium bolted joints

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    Full Text Available This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces versus sixth tightening (spoiled surfaces. The study considers M8x1.25 8.8 galvanized screws.

  9. Performance of bolted closure joint elastomers under cask aging conditions

    Energy Technology Data Exchange (ETDEWEB)

    Verst, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Sindelar, R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Skidmore, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Daugherty, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-07-23

    The bolted closure joint of a bare spent fuel cask is susceptible to age-related degradation and potential loss of confinement function under long-term storage conditions. Elastomeric seals, a component of the joint typically used to facilitate leak testing of the primary seal that includes the metallic seal and bolting, is susceptible to degradation over time by several mechanisms, principally via thermo-oxidation, stress-relaxation, and radiolytic degradation under time and temperature condition. Irradiation and thermal exposure testing and evaluation of an ethylene-propylene diene monomer (EPDM) elastomeric seal material similar to that used in the CASTOR® V/21 cask for a matrix of temperature and radiation exposure conditions relevant to the cask extended storage conditions, and development of semiempirical predictive models for loss of sealing force is in progress. A special insert was developed to allow Compressive Stress Relaxation (CSR) measurements before and after the irradiation and/or thermal exposure without unloading the elastomer. A condition of the loss of sealing force for the onset of leakage was suggested. The experimentation and modeling being performed could enable acquisition of extensive coupled aging data as well as an estimation of the timeframe when loss of sealing function under aging (temperature/radiation) conditions may occur.

  10. Modeling and simulation of Polymer Composite laminate bolted Joint

    Directory of Open Access Journals (Sweden)

    B. Sutharson

    2013-10-01

    Full Text Available Environmental awareness today motivates the researchers, worldwide on the studies of natural fiber reinforced polymer composite and cost effective option to synthetic fiber reinforced composites. This work is concerned with the modeling and simulation of bearing properties of hybrid fiber polymer composite mechanical joint using Artificial Neural Network (ANN. In general it was found that increase in bearing capacity was always with increasing the e/d and w/d ratio. However, the extent of increase/decrease depends on the type of stacking sequence. There was increase in strength with rise in natural fiber loading. In this study, an artificial neural network is developed to predict the response of bolt-loaded fiber reinforced polymer composite plates. To predict the behavior of the laminate failure, a multilayered feed-forward neural network trained with the back-propagation algorithm is constructed. The ANN was trained and verified using experimental data. Comparisons of ANN results with desired values showed that there is a good agreement between input and output variables of the experimental data. The results indicate that ANN was illustrated to be a valid useful and powerful tool for the prediction of bearing properties predictions of bolted joints in composite laminates.

  11. Finite Element Modeling and Modal Analysis of Complicated Structure with Bolted Joints

    Institute of Scientific and Technical Information of China (English)

    PU Da-yu; LIAO Ri-dong; ZUO Zheng-xing; FENG Hui-hua

    2009-01-01

    A contact bolt model is proposed as a new modeling technique to investigate the complex structure with bolted joints for modal analysis and compared with the coupled bolt model, and the test results are given. Among these models, the coupled bolt model provides the best accurate responses compared with the experimental results. The contact bolt model shows the best effectiveness and usefulness in view of operational time. The bolt models proposed in this study are adopted for a dynamic characteristic analysis of a large diesel engine consisting of several parts which are connected by many bolts. The dynamic behavior of the entire engine structure was investigated by experiment. The coupled bolt model and the contact bolt model were applied to model the assembly of engine with high preload. The experimental results are in good agreement with the finite element method (FEM) results. Compared with the other models, the contact bolt model presented in this paper is more effective and useful in view of operational time and experience of analysts.

  12. Asymptotic Analysis of the Load Transfer on Double-Lap Bolted Joints

    OpenAIRE

    KRATOCHVIL, Jan

    2012-01-01

    In this thesis, the complex potential method along with the method of compound asymptotic expansions is applied to the analysis of selected problems of plane elasticity related to double-lap bolted joints. The contribution to the thesis lies in the construction of several closed-form approximations of solutions to the considered problems. After a brief introduction of the basic theoretical concepts in Chapter 2, a mathematical model of a double-lap bolted joint is presented in Chapter 3....

  13. Health monitoring of bolted joints using the time reversal method and piezoelectric transducers

    Science.gov (United States)

    Tao, Wang; Shaopeng, Liu; Junhua, Shao; Yourong, Li

    2016-02-01

    In this paper, the time reversal method based on piezoelectric active sensing is investigated for health monitoring of bolted joints. Experiments are conducted on bolted joints to study the relationship between the time reversal focused signal peak amplitudes and the bolt preload. Two piezoelectric patches are bonded on two different sides of a bolted joint. Any one of the piezoelectric patches can be used as an actuator to generate an ultrasonic wave, and the other one can be used as a sensor to detect the propagated wave. With the time reversal method, the received response signal is reversed in the time domain and then is re-emitted as an excitation signal to acquire the time reversal focused signals. The experimental results show that the time reversal focused signal peak amplitudes increase with the increasing bolt preload until reaching saturation, and when the bolt preload increases to a certain value, the focused signal peak amplitudes will remain unchanged. Experiments show that the surface roughness of the bolted joint impacts the saturation value. A higher surface roughness value corresponds to a higher saturation value. In addition, the proposed method has a high signal to noise ratio benefiting from the time reversal method time and space focusing ability.

  14. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Crescimanno, P.J.; Keller, K.L.

    1981-03-01

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples.

  15. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    International Nuclear Information System (INIS)

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples

  16. Analysis profile of the fully grouted rock bolt in jointed rock using analytical and numerical methods

    Institute of Scientific and Technical Information of China (English)

    Ghadimi Mostafa; Shahriar Kourosh; Jalalifar Hossein

    2014-01-01

    The purpose of this study was to investigate the effect of bolt profile on load transfer mechanism of fully grouted bolts in jointed rocks using analytical and numerical methods. Based on the analytical method with development of methods, a new model is presented. To validate the analytical model, five different profiles modeled by ANSYS software. The profile of rock bolts T3 and T4 with load transfer capacity, respectively 180 and 195 kN in the jointed rocks was selected as the optimum profiles. Finally, the selected profiles were examined in Tabas Coal Mine. FLAC analysis indicates that patterns 6+7 with 2NO flexi bolt 4 m better than other patterns within the faulted zone.

  17. Seismic Properties of Moment-resisting Timber Joints with a Combination of Bolts and Nails

    Directory of Open Access Journals (Sweden)

    Awaludin A.

    2011-01-01

    Full Text Available Improvement of cyclic or dynamic performance of timber connections has been intensively conducted since the overall response of wooden structures is merely a function of joint performance. For a bolted joint, filling the lead-hole clearance with epoxy resin or gluing high embedding-strength materials at the interface of the individual timber member are probably the most common methods. This study presents cyclic test results of moment-resisting joints with a combination of bolts and nails. The nails were placed closer to the joint centroid than the bolts, acting as additional fasteners and were expected to improve the seismic performance of the joints. Static-cyclic test results confirmed the increase of joint stiffness and moment resistance due to the additional nails. The nails contribute to the increase of hysteretic damping significantly though pinching behavior or narrowing the hysteresis loops close to zero rotation points was still observed. The results indicated that contribution of nails or bolts on moment resistance and hysteretic damping can be superimposed.

  18. Thermal conductance measurements of bolted copper joints for SuperCDMS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R.; Tatkowski, Greg; Ruschman, M.; Golwala, S. R.; Kellaris, N.; Daal, M.; Hall, Jeter C.; Hoppe, Eric W.

    2015-09-01

    Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

  19. Thermal conductance measurements of bolted copper joints for SuperCDMS

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, R. L. [Fermilab; Tatkowski, G [Fermilab; Ruschman, M. [Fermilab; Golwala, S. [Caltech; Kellaris, N. [UC, Berkeley; Daal, M. [UC, Berkeley; Hall, J. [PNL, Richland; Hoppe, E. W. [PNL, Richland

    2015-05-22

    Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

  20. Effect of Fully Grouted Passive Bolts on Joint Shear Strength Parameters in a Blocky Mass

    Science.gov (United States)

    Srivastava, Lok Priya; Singh, Mahendra

    2015-05-01

    The present paper discusses an experimental study on shear strength response of unreinforced and reinforced block masses to find out the effect of fully grouted passive bolts on the shear strength parameters of joints in a mass. Direct shear tests were conducted on specimens of large-sized blocky masses, each with a dimension of 750 × 750 × 900 mm. Each blocky mass was assembled by piling elemental blocks of size 150 × 150 × 150 mm. For the reinforced condition, the mass was reinforced with three, five, and nine bolts perpendicular to the shear plane. The tests were conducted at different normal stress levels ranging from 0 to 2 MPa, which are common in rock slopes. Results from the tests show that passive bolts enhance the joint shear strength parameters. The strength enhancement is mainly due to improved interlocking and therefore, enhanced cohesion. The value of enhanced cohesion depends on the bolt area, the ratio of bolt spacing to block size and the strength of the intact material for a given set of steel and grout. A correlation has been established to find out enhanced cohesion for the given joints in the mass.

  1. Parameter analysis of anchor bolt support for large-span and jointed rock mass

    Institute of Scientific and Technical Information of China (English)

    LI Xi-bing; ZHOU Zi-long; LI Qi-yue; HU Liu-qing

    2005-01-01

    In order to obtain the optimal parameters of anchor bolt supporting system for large-span and jointed rock mass in Kaiyang Phosphor Mine, it is expensive and unavailable with the method of in-situ experiments. This paper describes a numerical modeling with discrete element method for the supporting effects of different type of anchor bolts. The anchor bolts with variant length of 0.5 m, 0.8 m, 1.0 m, diameter of 10 mm, 15 mm, 20 mm, setting spacing of 3.0 m, 2.5 m, 2.0 m, and setting angle of 10°, 20°, 30°, are simulated respectively. The results show that there exist optimal parameters of anchor bolt support for large-span and jointed rock mass. For the bolt support of the concerning, the optimal length is 2.5-3.5 m, the diameter is 25-35 mm, the spacing is 0.5-0.6 m, and the setting angle is 105°.

  2. Behavior of Fiber Glass Bolts, Rock Bolts and Cable Bolts in Shear

    Science.gov (United States)

    Li, Xuwei; Aziz, Naj; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-07-01

    This paper experimentally compares the shear behavior of fiber glass (FG) bolt, rock bolt (steel rebar bolt) and cable bolt for the bolt contribution to bolted concrete surface shear strength, and bolt failure mode. Two double shear apparatuses of different size were used for the study. The tensile strength, the shear strength and the deformation modulus of bolt control the shear behavior of a sheared bolted joint. Since the strength and deformation modulus of FG bolt, rock bolt and cable bolt obtained from uniaxial tensile tests are different, their shear behavior in reinforcing joints is accordingly different. Test results showed that the shear stiffness of FG bolted joints decreased gradually from the beginning to end, while the shear stiffness of joints reinforced by rock bolt and cable bolt decreased bi-linearly, which is clearly consistent with their tensile deformation modulus. The bolted joint shear stiffness was highly influenced by bolt pretension in the high stiffness stage for both rock bolt and cable bolt, but not in the low stiffness stage. The rock bolt contribution to joint shear strength standardised by the bolt tensile strength was the largest, followed by cable bolts, then FG bolts. Both the rock bolts and cable bolts tended to fail in tension, while FG bolts in shear due to their low shear strength and constant deformation modulus.

  3. Numerical Computation of Stress Intensity Factors for Bolt-hole Corner Crack in Mechanical Joints

    Institute of Scientific and Technical Information of China (English)

    Wang Liqing; Gai Bingzheng

    2008-01-01

    The three-dimensional finite element method is used to solve the problem of the quarter-elliptical comer crack of the bolt-hole in mechanical joints being subjected to remote tension. The square-root stress singularity around the corner crack front is simulated using the collapsed 20-node quarter point singular elements. The contact interaction between the bolt and the hole boundary is considered in the finite element analysis. The stress intensity factors (SIFs) along the crack front are evaluated by using the displacement correlation technique. The effects of the amount of clearance between the hole and the bolt on the SIFs are investigated. The numerical results indicate that the SIF for mode I decrease with the decreases in clearance, and in the cases of clearance being present, the corner crack is in a mix-mode, even if mode I loading is dominant.

  4. A contribution to the selection and calculation of screws in high duty bolted joints

    International Nuclear Information System (INIS)

    The paper deals with the assessment of the correct design methodology that allows selecting the appropriate screw (in terms of reference nominal diameter) to be used in high duty bolted joints. Some Standards or Guidelines are analysed and discussed although the most complete appears the VDI-2230 (February 2003); in many cases the simplifications adopted can only be effective in presence of steel screws clamped on steel plates (often considered as rigid in comparison to the screw) and by considering coefficients of friction which vary in a narrow range (0.15–0.20). Hence, the increasing use of lightweight materials in recent years (e.g. magnesium, aluminium and titanium), as well as design optimisations, is forcing the screw designers to perform an attentive selection of the most appropriate fastening connection. For these reasons, this contribution tries to give a compressed, but comprehensive and clearly structured view about the maximum equivalent stress acting on the bolt as a function of the actual joint parameters (e.g. ratio between tensile and shear forces acting on the joint, ratio between bolt and plates stiffness, effect of coefficient of friction, static or fatigue loads). Highlights: ► The paper presents an innovative method for selecting of ISO metric screws. ► The screws have to be used in high duty bolted joints for lightweight connections. ► Some standards have been deeply analysed. ► The nominal stress acting on the bolt has been accurately determined. ► The most important parameter to be actually controlled is the thread coefficient of friction.

  5. Numerical and experimental analysis on load sharing & optimization of the joint parameters of polymer composite multi bolted joints

    Science.gov (United States)

    Latha Shankar, B.; Sudeep Kumar, T.; Shiva Shankar, G. S.

    2016-09-01

    In the present work, the bearing failure of composite bolted connections of composite laminates was analysed both experimentally and numerically. The glass fiber woven mat 600GSM/ epoxy composite laminates were prepared using wet-layup technique. The process parameters were taken care during preparation of laminates. Examination is done for various estimations of edge-to-hole diameter and width-to-hole diameter proportion. Stress is evaluated in laminates by utilizing Hart-Smith criteria. Ideal estimation of e/d proportion, d/w proportion is recommended for most extreme effectiveness. A numerical technique is utilized for the rough determination of a load shared by bolts in a numerous "bolted" joints loaded in tension were investigated experimentally and numerically. The effect of un-evenness in load shearing is suggested.

  6. Round timber bolted joints reinforced with modified washers and self-drilling screws

    Directory of Open Access Journals (Sweden)

    Antonín Lokaj

    2016-03-01

    Full Text Available Timber constructions made of round timber components are becoming more and more popular. Given that in the current European standards for the design of timber structures, timber-to-timber joint type is solved only for squared timber. This paper presents results of static tests in tension at an angle of 0°, 90°, 60° to the grain of round timber bolted joints. This research looks into reinforcement with modified washers or self-drilling screws, as these are the least labour-intensive (while economically advantageous. The joints samples were experimentally tested in the laboratory of the Faculty of Civil Engineering VŠB TU Ostrava.

  7. Mathematical representation of bolted-joint stiffness: A new suggested model

    International Nuclear Information System (INIS)

    Joint member stiffness in a bolted connection directly influences the safety of a design in regard to both static and fatigue loading, as well as in the prevention of separation in the connection. This work provides a new simple model for computing the member stiffness in bolted connections for both fully and partially developed stress envelope fields. The new model is built using a stress distribution polynomial of third order. Finite element analysis (FEA) is performed for some joints geometries, and the results are used to estimate the best analytical envelope angle in the proposed analytical model that gives suitable convergence between the compared results. An experimental effort is exerted to validate the accuracy of a suggested model. When analytical results are compared with FEA results and experimental data, the maximum absolute percentage errors are found to be 2.69 and 14.69, respectively. Also, a good agreement is obtained when the analytical results are compared with other researchers' results

  8. A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

    International Nuclear Information System (INIS)

    Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. 1. Sense changes in the clamping force of the joint and report this fact. 2. Provide compatibility with the large dynamic range of clamping force. 3. Satisfy the limitations in terms of physical size. 4. Provide the means to electronically interface with the washer. 5. Provide a means of powering the washer in situ. 6. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show

  9. Combined In-Plane and Through-the-Thickness Analysis for Failure Prediction of Bolted Composite Joints

    Science.gov (United States)

    Kradinov, V.; Madenci, E.; Ambur, D. R.

    2004-01-01

    Although two-dimensional methods provide accurate predictions of contact stresses and bolt load distribution in bolted composite joints with multiple bolts, they fail to capture the effect of thickness on the strength prediction. Typically, the plies close to the interface of laminates are expected to be the most highly loaded, due to bolt deformation, and they are usually the first to fail. This study presents an analysis method to account for the variation of stresses in the thickness direction by augmenting a two-dimensional analysis with a one-dimensional through the thickness analysis. The two-dimensional in-plane solution method based on the combined complex potential and variational formulation satisfies the equilibrium equations exactly, and satisfies the boundary conditions and constraints by minimizing the total potential. Under general loading conditions, this method addresses multiple bolt configurations without requiring symmetry conditions while accounting for the contact phenomenon and the interaction among the bolts explicitly. The through-the-thickness analysis is based on the model utilizing a beam on an elastic foundation. The bolt, represented as a short beam while accounting for bending and shear deformations, rests on springs, where the spring coefficients represent the resistance of the composite laminate to bolt deformation. The combined in-plane and through-the-thickness analysis produces the bolt/hole displacement in the thickness direction, as well as the stress state in each ply. The initial ply failure predicted by applying the average stress criterion is followed by a simple progressive failure. Application of the model is demonstrated by considering single- and double-lap joints of metal plates bolted to composite laminates.

  10. Failure analysis of bolted joints in foam-core sandwich composites

    DEFF Research Database (Denmark)

    Zabihpoor, M.; Moslemian, Ramin; Afshin, M.;

    2008-01-01

    This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed. These...... using 3D FEM in ANSYS commercial code. Tsai-Wu failure criterion is used in the failure analysis. The results indicate that the most important parameter in the proposed joint zone design is the foam -solid laminate interface angle which plays an important role on the value of failure criterion (damage...... analysis, the increase of solid laminate size or interface angle could result in considerable higher buckling strength....

  11. Experimental study of bolted connections using light gauge channel sections and packing plates at the joints

    Science.gov (United States)

    Kulkarni, Ravindra B.; Vaghe, Vishal M.

    2014-12-01

    Cold-formed structural members are being used more widely in routine structural design as the world steel industry moves from the production of hot-rolled section and plate to coil and strip, often with galvanized and/or painted coatings. Steel in this form is more easily delivered from the steel mill to the manufacturing plant where it is usually cold-rolled into open and closed section members. In the present experimental study, the use of packing plate at the joints in cold-formed channel sections may increase the load carrying capacity and also reduce the buckling of unconnected cold form channel steel plate at joints. The present study focuses on examining the experimental investigation to use mild steel as a packing plate with cold-formed channel sections by bolted connection at the joints and the connection subjected to axial tension. Series of tests are carried out with increase in the thickness of packing plate and results are observed and analyzed. Total Twelve experimental tests have been carried out on cold-formed channel tension members fastened with single as well as three numbers of bolts at the connection and from the observations the strength of the joint is increased by increasing the various thicknesses of packing plates and also the buckling of unconnected leg of channel specimen is reduced. It is analyzed by plotting the entire load versus elongation path, so that the behavior of the connection is examined.

  12. Failure behavior for composite single-bolted joints in double shear tension

    Science.gov (United States)

    Tang, Zhanwen; Liu, Hanyang; Yang, Zhiyong; Shi, Hanqiao; Sun, Baogang

    2016-05-01

    In order to improve the reliability and load carrying capacity of composite laminates structures which were lap jointed by bolt, in this paper, the failure strength and failure mode of laminated composite pinned-joints is investigated. To determine the effects of joint geometry and stacking sequence on the bearing strength and damage mode, the multi-scale numerical model combining with the Generalized Method of Cells (GMC) and considering the failure and the damage of constituent materials was created based on the ABAQUS and its user subroutine (USDFLD). A three-dimensional finite element technique was used for the stress analysis. Based on the three-dimensional state of stress of each element, different failure modes were detected by the failure theories of constituent materials, all of which are applied at the fiber, matrix and fiber-matrix interface constituent level. Numerical simulations have been carried out by which edge distance-to-hole diameter ratio, and plate width-to-hole diameter ratio are varied, The composite laminated plates are stacked with the following four different orientations: [+45/-45]2s, [90/+45/-45]s, and [0/90/0]s, the results show that failure mode and bearing strength are closely related to by stacking sequence of plates and geometrical parameters. Finally, the ultimate strength and failure modes of composite bolted joints in static tension double-shear loading conditions are predicted by using the progressive damage method established and the effects of layup and dimension of laminates on the properties of the connection structure were researched in this paper. An excellent agreement is found between data obtained from this study and the experiment.

  13. Multi-field coupled sensing network for health monitoring of composite bolted joint

    Science.gov (United States)

    Wang, Yishou; Qing, Xinlin; Dong, Liang; Banerjee, Sourav

    2016-04-01

    Advanced fiber reinforced composite materials are becoming the main structural materials of next generation of aircraft because of their high strength and stiffness to weight ratios, and excellent designability. As key components of large composite structures, joints play important roles to ensure the integrity of the composite structures. However, it is very difficult to analyze the strength and failure modes of composite joints due to their complex nonlinear coupling factors. Therefore, there is a need to monitor, diagnose, evaluate and predict the structure state of composite joints. This paper proposes a multi-field coupled sensing network for health monitoring of composite bolted joints. Major work of this paper includes: 1) The concept of multifunctional sensor layer integrated with eddy current sensors, Rogowski coil and arrayed piezoelectric sensors; 2) Development of the process for integrating the eddy current sensor foil, Rogowski coil and piezoelectric sensor array in multifunctional sensor layer; 3) A new concept of smart composite joint with multifunctional sensing capability. The challenges for building such a structural state sensing system and some solutions to address the challenges are also discussed in the study.

  14. Effect of parameters on local stress field in single-lap bolted joints with the interference fit

    Directory of Open Access Journals (Sweden)

    Jiefeng Jiang

    2016-05-01

    Full Text Available From the interference fit bolt installation to tensile loading stage in single-lap joint with a hi-lock bolt, the stress and strain fields were studied experimentally and numerically. A three-dimensional finite element model was generated to simulate the experimental setup, which was validated using the experimental data. The fatigue behavior of the bolted joint is influenced by the local stress fields on the faying surface near the holes in single-lap joints. Therefore, with the aim to improve design awareness, the effects of the parameters on the local stress fields were investigated by means of finite element simulation. With an increase in the interference fit size, the occurred position of the maximum stress values on the upper plate faying surface moves away from the hole edge gradually. As the clamping force or friction coefficient increases, the position of larger stress area is changed to the side of bearing load from the transverse direction. The lap geometry of the bolted joint as well as the amplitude of tensile load has apparent impact on the maximum stress value.

  15. INJECTION MOLDING AND STRUCTURAL ANALYSIS IN METAL TO PLASTIC CONVERSION OF BOLTED FLANGE JOINT BY CAE

    Directory of Open Access Journals (Sweden)

    Marian Blaško

    2014-12-01

    Full Text Available Many metal parts in various applications are being replaced by plastic parts. There are several reasons for that depending on actual application - minimize part cost, enhance corrosion resistance, integrating more components into one part etc. Most important steps of metal to plastic conversion are material selection and design of plastic part. Plastic part has to withstand the same load as metal part. To fulfill this requirement fiber reinforced engineering plastics are often used. Also it is convenient to substitute heavy wall sections with ribbed structure to increase load-carrying ability of part and decrease cycle time, eliminate voids, sink marks etc. Mechanical properties of such part could be highly affected by fiber orientation. Results of fiber orientation from injection molding filling analysis can be used in stress analysis for better prediction of part response to mechanical load. Such coupled analysis is performed here in this case study on bolted flange joint.

  16. The ITER EC H and CD upper launcher: Design, analysis and testing of a bolted joint for the Blanket Shield Module

    Energy Technology Data Exchange (ETDEWEB)

    Gessner, Robby, E-mail: robby.gessner@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany); Aiello, Gaetano; Grossetti, Giovanni; Meier, Andreas [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany); Ronden, Dennis [DIFFER – Dutch Institute for Fundamental Energy Physics, P.O. Box 1207, NL-3430 BE Nieuwegein (Netherlands); Spaeh, Peter; Scherer, Theo; Schreck, Sabine; Strauss, Dirk; Vaccaro, Alessandro [Karlsruhe Institute of Technology, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe (Germany)

    2013-10-15

    Highlights: ► The BSM of the ECH Launcher is attached to the Launcher Main Frame by a bolted joint. ► The bolts were designed as “captive” in order to avoid their accidental removal from the joint. ► The bolted flange connection using two sets of 15 captive bolts (M22 × 2) placed along the sides. ► The captive bolt design is based on a concept that uses a dedicated spring ring, a standard spiral spring and a tensioning screw with two threads to secure the bolts in a form-locking stop. -- Abstract: The final design of the structural system for the ITER EC H and CD upper launcher is in progress. Many design features of the preliminary design are under revision with the aim to achieve the built-to-print-status. This paper deals with design and analysis of a bolted joint for the Blanket Shield Module with special perspective on Remote Handling capability. The BSM of the ECH Launcher is attached to the Launcher Main Frame by a bolted joint conceived so that in the Hot Cell Facility, RH maintenance can be performed on internal components. The joint must be capable to resist very high Electro-Magnetic loads from disruptions, while it has to sustain substantial thermal cycling during operation. Thus the need for a rigid and reliable design is essential. Beside the set of pre-stressed bolts the flanges were therefore equipped with additional shear keys to divert radial moments away from the bolts. Main focus of the work performed was the mechanical design of the joint and the assessment of the structural integrity with respect to the loads applied and its capability for maintenance by RH procedures. To fulfill a major aspect of the RH requirements, the bolts were designed as “captive” in order to avoid their accidental removal from the joint. The captive bolt design is based on a concept that uses a dedicated spring ring, a standard spiral spring and a tensioning screw with two threads to secure the bolts in a form-locking stop. The final approval phase of

  17. 胶合木外夹钢板群螺栓连接力学性能的试验研究%Experimental study on mechanics performance of multi-bolt steel-glulam-steel joints

    Institute of Scientific and Technical Information of China (English)

    徐德良; 刘伟庆; 刘子彤; 周叮

    2011-01-01

    采用8组40个连接试件,考察胶合木外夹钢板群螺检连接构件在顺纹受拉时的力学性能,探讨其破坏模式和受力机制.研究表明:胶合木外夹钢板群螺栓连接的破坏模式、承载力、刚度和延性与螺栓列数、每列的螺栓数、螺栓的布置方式有关;承载力不具有由螺栓数线性叠加的性质;螺栓总数不变、多列布置螺栓延性较佳.%The mechanics performance of multi-bolt steel-glulam-steel joints subjected to a load parallel to grain was investigated with 8 groups of 40 multi-bolt joints specimens. The failure mode and its mechanism were discussed. For multi-bolt steel-glulam-steel joints, results showed that the failure modes,bearing capacity , stiffness, and ductility were relevant to the rows of bolts, the number of bolts in a row and the way of bolts arranged. The bearing capacity of multi-bolt joints was nonlinear number of bolts. With the same number of bolts, the ductility of bolts arranged in multi-rows was better than that of one-row.

  18. Bolting applications

    Energy Technology Data Exchange (ETDEWEB)

    Czajkowski, C J

    1984-05-01

    An investigation of bolting practices specific to the nuclear industry was performed. The report covered a large spectrum of topics e.g. bolts embedded in concrete, specifications, inspection of bolting, both at receipt and inservice. Plots of preload versus yield strength for different bolting materials in different environments are presented as well as information relative to the stress corrosion cracking resistance of the more recent reactor internals bolting materials A286 and Inconel X-750. Part of the report contains input by Standard Pressed Steel Inc. (a bolting consultant) relative to bolting standards, cottering methods and potential areas for bolting improvement.

  19. 参数化建模的螺栓法兰连接刚度分析%Stiffness analysis of bolted flange joint based on parameterized modeling

    Institute of Scientific and Technical Information of China (English)

    蒋国庆; 李家文; 唐国金

    2014-01-01

    为分析几何参数对螺栓法兰连接刚度的影响,用 MSC.Patran 软件的二次开发工具 PCL(Patran Command Language)建立了螺栓法兰连接的参数化模型。研究了螺栓法兰连接刚度随连接结构几何参数的变化规律并进行了灵敏度分析。经分析可知,连接结构刚度对开孔位置比例参数最敏感,其次是上法兰厚度。当上部段长度大于某一数值时,连接结构刚度对上部段长度参数不敏感,这一结论能为连接结构动力学简化建模提供一定理论参考。%In order to analyze the effects of geometric parameters on the stiffness of bolted flange joint,a parameterized model of bolted flange joint was constructed by using PCL (Patran Command Language)on the platform of software MSC.Patran.The law of the stiffness of bolted flange joint with the change of geometric parameters was studied,and the sensitivity of geometric parameters was analyzed based on the parameterized model.The results show that the ratio of the location of hole is the most sensitive factor to the stiffness of bolted flange joint,and the next one is thickness of upper flange.When the length of upper body is up to a const,the stiffness of bolted flange joint is insensitive to the length of upper body,and this conclusion can provide a reference to simplify the dynamic model of joint.

  20. A novel approach to predict the pin load distribution of multiple bolt-jointed composite laminate based on the circuit model

    Science.gov (United States)

    Yang, Xiankun; Chen, Haoyuan; Cheng, Linan; Zheng, Xitao

    2012-04-01

    The circuit model was applied to predict the pin load distribution of composite multiple bolt-joint structure. The load, flexibility and deformation of the mechanics model were equivalent to the current, resistance and voltage of the circuit model, respectively. Based on the above assumption, it could be found that the Hooke's law and the deformation compatibility equation in the origin mechanics model transformed into the Ohm's law and the voltage balance equation in the new circuit model. This approach translated the complex model of composite multiple bolt-jointed into a simple circuit model which consisted of some series circuits and parallel circuits. The analysis of the new circuit model had formed n-1 independence voltage balance equations and a current balance equation, thus, the current and load of each bolt could be calculated. In the new model, power sources which were added as required in some branch circuits could also simulate the clearance or interference in the origin model. Compared with the result of the multiple bolt-joints composite laminate test, the new approach could make an excellent performance to estimate the load distribution.

  1. Synthetical deformation analysis of anchor bolt in jointed rock mass%节理岩体锚杆的综合变形分析

    Institute of Scientific and Technical Information of China (English)

    张伟; 刘泉声

    2012-01-01

    在总结国内外对节理岩体中锚杆加固机制的试验研究和理论探讨基础上,综合考虑锚杆的切向和轴向变形能力,建立节理锚固锚杆在剪切荷载作用下的变形模型,将节理锚固锚杆的变形区划分为弹性变形段和挤压破坏段,引入表征挤压破坏段长度的变量,对锚杆与岩体的相互作用机制进行理论分析,推导了剪切荷载与剪切位移和轴向荷载与轴向位移的关系.通过分析锚杆的屈服破坏形式,得到了确定挤压破坏段长度的方法.最后,通过算例分析了挤压破坏段长度与锚杆直径、岩体强度、锚固角度等参数的关系,得到了以下结论:(1)节理锚固锚杆抗剪作用的实质是锚杆调动岩体的抗压强度抵抗节理切向荷载.在抗压强度较高的硬岩中,挤压破坏段局限于节理面附近,锚杆影响范围小;而在抗压强度较低的软岩中,挤压破坏段较大,而且会产生较大的剪切变形,锚杆影响范围较大.(2)锚杆屈服破坏形式与岩质和锚杆直径有关.硬质岩体发生剪切屈服,而较软岩体中容易发生弯曲屈服;小直径锚杆一般直接剪切屈服,而大直径锚杆可能发生弯曲屈服.锚杆屈服破坏后出现塑性铰,挤压破坏段范围在节理一侧约为直径的1~2倍,继续增加剪切荷载,挤压破坏段长度不再增大.(3)随岩质的不同,锚杆锚固节理的最优锚固角变化较大.岩质较硬时,最优锚固角度较小,反之则较大.%Based on the former experimental and theoretical researches on the reinforcement mechanisms of anchor bolt in jointed rock mass at home and abroad, and comprehensive considering of the tangential and axial deformability of anchor bolt, a deformation model of joint bolts under shear load is proposed. The deformation of joint bolts is divided into two parts: elastic deformation zone and crushing failure zone. A variable is introduced to express the length of crushing failure zone. Mechanism

  2. Dynamic and Stability of Harmonic Driving Flexible Cartesian Robotic Arm with Bolted Joints Based on the Sensitivity and Multiple Scales Method

    Directory of Open Access Journals (Sweden)

    Yufei Liu

    2015-01-01

    Full Text Available Flexible Cartesian robotic arms (CRAs are typical multicoupling systems. Considering the elastic effects of bolted joints and the motion disturbances, this paper investigates the dynamic and stability of the flexible CRA. With the kinetic energy and potential energy of the comprising components, Hamilton’s variational principle and Duhamel integral are utilized to derive the dynamic equation and vibration differential equation. Based on the proposed elastic restraint model of the bolted joints, boundary conditions and mode equations of the flexible CRA are determined with using the principle of virtual work. According to the mode frequencies and sensitivities analysis, it reveals that the connecting stiffness of the bolted joints has significant influences, and the mode frequencies are more sensitive to the tensional stiffness. Moreover, describing the motion displacement of the driving base as combination of an average motion displacement and a harmonic disturbance, the vibration responses of the system are studied. The result indicates that the motion disturbance has obvious influence on the vibration responses, and the influence enhances under larger accelerating operations. The multiple scales method is introduced to analyze the parametric stability of the system, as well as the influences of the tensional stiffness and the end-effector on the stability.

  3. Analytical large deformation shear strength for bolted rough discontinuous rock

    Institute of Scientific and Technical Information of China (English)

    LIU Bo(刘波); TAO Long-guang(陶龙光); YUE Zhong-qi(岳中琦)

    2004-01-01

    Presented a new analytical model for studying the shear-tensile large deformation behavior near the vicinity of joint interface for bolted rough discontinuous rock, and presented the formulation estimating global shear strength for bolted joints under shearing-tensile loads. The analytical strength curves of bolts contribution on reinforced discontinuous rocks as the function of joint displacements or deformation angle of a bolt at rock joints was obtained. Based on Barton's equation on JRC roughness profiles, the theoretical shearing strength of bolted rough joints was also established. Test results on bolted granite and marble specimen confirm the validity of the analytical approach.

  4. Rock bolts - Improved design and possibilities

    OpenAIRE

    Thomas-Lepine, Capucine

    2012-01-01

    SummaryRock Bolts, improved design and possibilitiesMaster thesis NTNU 2012Student : Capucine Thomas-LepineSupervisor : Leif LiaKey words : rock foundation, small concrete dam, rock mass classification, rock joints, shear strength of rock discontinuities, fully grouted passive rock bolts designMasters Thesis : “Rock bolts, improved design and possibilities” is a continuation from the Masters Thesis NTNU 2011 “Rock bolts in dams, expected capacity” by Lars Kristian Neby. In...

  5. Study on the design of bolted spherical joints%螺栓球节点设计方法研究

    Institute of Scientific and Technical Information of China (English)

    杜新喜; 刘茂青; 程晓燕

    2012-01-01

    Diameter selection formulas in accordance with precise geometrical controlling conditions were deduced, which revises the specification formulas and perfects the controlling formulas for cone-shaped connectors( or end plates) and steel pipe with small included angle. Seven space truss structure nodes were designed by specification formula and paper formula respectively. The contrast results show that the steel consumption of paper formulas (which take fabrication errors into account) is less than that of specification formulas when the included angle is reasonable. When the included angle is small, according to the controlling formulas for cone-shaped connector (or end plate) and steel pipe, the diameter of bolted spherical joints calculated with paper formulas could be increased which could avoid collision between pipes.%按照准确的螺栓球几何控制条件,推导了螺栓球直径控制公式,从而对规程公式进行修正,并完善了杆件夹角较小时锥头(封板)和杆件控制公式。用规程公式和本文公式(考虑螺栓球配件制作各项误差)对7种节点进行设计,对比发现:当杆件夹角较为合理时,本文公式螺栓球节点用钢量明显低于规程公式用钢量;当杆件夹角较小时,按照锥头(封板)和杆件控制公式,本文公式能够增大螺栓球直径,从而避免杆件相碰。

  6. Bolt Analysis Program

    Science.gov (United States)

    Travis, Brandon E.

    2004-01-01

    In designing and testing bolted joints there are multiple parameters to be considered and calculations that must be performed to predict the joint behavior. Each different set of parameters may call for a different set of equations. Determining every parameter in each bolted joint is impractical and in many cases impossible. On the other hand, it is much easier to reduce these calculations to a universal set that can be used for all bolted joints. This is the purpose of the Bolt Analysis Program. My project under the Mechanical and Rotating Systems branch of the Engineering Development and Analysis Division was to take the Bolt Analysis Program Version 2.0 and update the program to a modem and user-friendly format. Version 2.0 of the Bolt Analysis Program is a useful program, but lacks the dynamic capabilities that are needed for current applications. Version 2.0 of the Bolt Analysis Program was written in 1993 using the Pascal programming language in a DOS format. This program allows you to input data in a step-by-step format, calculates the data, and then on a final screen displays the input and the output fiom the calculations. Version 2.0 is still applicable for all bolted joint anaiysis, but has updates that are desired. First, the program runs in DOS format. With the applications available today, my mentor decided it would be best to update the program into Excel using Visual Basic for Applications (VBA). This would allow the program to have multiple Graphical User Interfaces (GUI s) while retaining all functions of the previous program. Version 2.0 only allows you to input data in a step-by-step process. If you make a mistake and need to go back, you must run through the entire program before you can return to fix your error. This becomes tedious when needing to change one parameter or test multiple sets of data. In Version 3.0, the program allows you to enter and change data at any time while displaying real-time output data. If you realize an error, it is

  7. 复合材料多钉连接数值计算方法研究%Numerical Method for Multi-bolt Composite Joint

    Institute of Scientific and Technical Information of China (English)

    冒颖; 刘龙权; 余音

    2011-01-01

    为了研究复合材料多钉机械连接特性,对板与螺栓进行受力分析.考虑连接板对螺栓产生的弯曲效应,建立适合于复合材料连接钉载分配的有限元计算方法.并从载荷-位移曲线方面对其进行比较验证.结果表明,相比传统方法,该方法能更精确地反映复合材料连接的实际特征.采用建模方法进一步研究了板与螺栓间的弯矩随厚度变化.最后使用MSC.Patran二次开发语言PCL编制相应程序,使用模块化方法实现本文数值计算方法的快速应用分析.%To study multi-bolt composite joints, a numerical method is developed to simulate composite joints through detail mechanical analysis of the multi-bolt area, considering the bending effect between interface of the bolts and the laminate wall.The method is validated by comparing load-displacement characteristics to experimental results, which is proved to be more accurate than the traditional method in explaining the real mechanical characteristic of composite joints.And then, the method is used to study the effects of plate thickness on bending in composite joints.Finally, a program, using MSC.Patran secondary development language PCL, is developed to realize the numerical method more efficiently.

  8. Stress analysis of closure bolts for shipping casks

    International Nuclear Information System (INIS)

    This report specifies the requirements and criteria for stress analysis of closure bolts for shipping casks containing nuclear spent fuels or high level radioactive materials. The specification is based on existing information conceming the structural behavior, analysis, and design of bolted joints. The approach taken was to extend the ASME Boiler and Pressure Vessel Code requirements and criteria for bolting analysis of nuclear piping and pressure vessels to include the appropriate design and load characteristics of the shipping cask. The characteristics considered are large, flat, closure lids with metal-to-metal contact within the bolted joint; significant temperature and impact loads; and possible prying and bending effects. Specific formulas and procedures developed apply to the bolt stress analysis of a circular, flat, bolted closure. The report also includes critical load cases and desirable design practices for the bolted closure, an in-depth review of the structural behavior of bolted joints, and a comprehensive bibliography of current information on bolted joints

  9. 木结构螺栓连接的力学性能研究进展%Reviews of Mechanical Properties for Timber Bolted Joints

    Institute of Scientific and Technical Information of China (English)

    张俊珍; 钟永; 赵荣军; 周海宾

    2012-01-01

    Bolted connections have been widely used in modern timber structures. Their mechanical properties are very important for designing safe and durable wood structures. The authors have summarized studies on timber bolt connections for predicting failure, as well as modeling strength and mechanical behaviors under fire and seismic conditions. The authors also have made some suggestions for future modeling mechanical behavior and reliability based on previous development in modern timber bolted joints.%螺拴连接已广泛用于现代木结构建筑中,系统研究其力学性能对建筑结构的安全性评估意义重大.本文从螺栓连接强度的预测方法、力学行为模拟、螺栓预紧、螺栓连接的破坏方式,以及抗火抗震条件下的力学性能等方面进行了总结归纳,针对目前的木结构螺栓连接中尚未解决的问题及有待进一步开展的研究项目,建议加强复螺栓连接的力学行为模拟、可靠性评价等研究.

  10. 胶合木与胶合木螺栓连接力学性能试验研究%Experimental study of bolted glued timber-to-timber joints

    Institute of Scientific and Technical Information of China (English)

    徐德良; 刘伟庆; 周叮; 奚爱峰

    2011-01-01

    试验研究胶合木与胶合木单螺栓连接及群螺栓连接构件在顺纹受拉时的承载能力,分析其破坏模式和破坏机理,试验对象为3组9个单螺栓连接和4组20个群螺栓连接.研究表明:胶合木与胶合木单螺栓连接的力学性能与胶合木的厚度比有关,当侧材厚度比为4.375时,破坏形态Ⅲ型,延性最佳;胶合木与胶合木群螺栓连接的力学性能与螺栓列数及每列的螺栓数有关,群螺栓连接承载力应考虑螺栓的有效个数.两列布置群螺栓,破坏形态螺栓受力较均匀的两列开裂,其延性与一列与三列相比最佳.%Three groups of 9 single-bolted connections and four groups of 20 multi-bolted connections were tested to investigate their mechanical performance. The bearing capacity of single-bolted and multi-bolted glued timber-to-timber connections subjected to a load parallel to grain was studied. The failure modes and failure mechanism of bolted connections were discussed in detail. For the single-bolted glued timber-to-timber connections, it is shown that the failure modes, bearing capacity, stiffness and ductility are related to the thickness ratio of the side members of the structure. When the thickness ratio of the side member is equal to 4. 375, the failure modes is type M. In such a case, the ductility is the best. For multi-bolted timber-to-timber connections, it shows that the failure modes, bearing capacity, stiffness and ductility are relevant to the bolt number in a row and the row number of bolts. The bearing capacity of the joint is relevant to the effective number of bolts rather than the total number of bolts. In all of the multi-row arrangements, the two-row cracks failure mode where the bolts are uniformly loaded exhibits the highest ductility. Glued timber structure; single-bolt glued timber-to-timber connection; multi-bolt glued timber-to-timber

  11. Overall bolt stress optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with International Organization for Standardization metric thread design is examined and optimized. The assumed failure mode is fatigue, so the applied preload and the load amplitude together with the stress concentrations define the connection strength....... Maximum stress in the bolt is found at the fillet under the head, at the thread start, or at the thread root. To minimize the stress concentration, shape optimization is applied. Nut shape optimization also has a positive effect on the maximum stress. The optimization results show that designing a nut...... change to the bolt head and the nut has the positive indirect effect of increasing the member stiffness, all leading to a smaller joint stiffness factor....

  12. 振动工况下螺栓连接自松弛机理研究%Self-loosening mechanism of bolted joints under vibration

    Institute of Scientific and Technical Information of China (English)

    王崴; 徐浩; 马跃; 刘海平

    2014-01-01

    为研究振动工况下螺栓连接自松弛机理,利用 ANSYS 参数化语言建立考虑螺纹的三维螺栓连接有限元模型,用降温法加载预紧力,进行螺栓连接横向振动瞬态分析;研究横向激励幅值、初始预紧力、螺纹啮合面、螺栓头及螺母承压面以及连接物之间结合面的摩擦因数等对螺栓连接自松弛影响。结果表明,横向振动时完全滑移先发生于螺纹啮合面处;横向激励幅值越小、初始预紧力越大、螺纹啮合面及螺栓头、螺母承压面摩擦因数越大,螺栓连接自松弛越不易发生;激励幅值一定时连接物间结合面摩擦因数对自松弛无影响,但摩擦因数越大,发生横向振动所需剪切载荷越大。研究结果对理解螺栓连接自松弛、指导防松设计具有重要意义。%Aiming at analyzing the self-loosening mechanism of bolted joints under vibration,a three dimensional FEA model of bolted joints,taking thread into consideration,was built by using the software ANSYS.Applying the preload on the bolted joints by the method of dropping temperature,the FE transient analysis on bolted joints under transverse cyclic excitation was conducted.The effects of transverse cyclic excitation's amplitude,initial preload,thread, bearing friction coefficients,and joints'surface friction coefficient on self-loosening were investigated.The results show that the complete thread slip occurs prior to the complete bearing surface slip under transverse vibration.The smaller the excitation amplitude is,the greater the initial preload is,and the bigger the thread and bearing friction coefficients are, the more difficult the occurance of self-loosening will be.The joints'surface friction coefficient has little relationship to self-loosening,however,the larger joints'surface friction coefficient makes the needed shearing force,which induces the transversal vibration,larger.These are of great significance for understanding of

  13. Experimental study and stress analysis of rock bolt anchorage performance

    Directory of Open Access Journals (Sweden)

    Yu Chen

    2014-10-01

    Full Text Available A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0°, 20°, 40°, 60°, and 90°, two joint gaps (0 mm and 30 mm, and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite were considered, and stress–strain measurements were conducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0° displacing angle (pure pull to approximately 70 mm at a displacing angle greater than 40°. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50% higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0° of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  14. Experimental study and stress analysis of rock bolt anchorage performance

    Institute of Scientific and Technical Information of China (English)

    Yu Chen

    2014-01-01

    A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0?, 20?, 40?, 60?, and 90?), two joint gaps (0 mm and 30 mm), and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite) were considered, and stressestrain measurements were con-ducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0? displacing angle (pure pull) to approximately 70 mm at a displacing angle greater than 40?. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50%higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0?) of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.

  15. A microprocessor based portable bolt tension monitor

    Science.gov (United States)

    Perey, D. F.

    1991-01-01

    A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

  16. Mechanism analysis of shear deformation of joint bolt based on elastic-plastic theory%基于弹塑性理论的节理处锚杆剪切变形机理分析

    Institute of Scientific and Technical Information of China (English)

    马超甫; 冯涛; 姚琦; 王平; 廖泽

    2016-01-01

    为了研究节理面处锚杆的剪切变形机制,建立了节理岩体中锚杆的受力模型,对锚杆在节理面处的剪切变形进行了理论分析,利用单位载荷法推导了节理面处锚杆竖向位移与载荷、节理宽度、材料性质间的关系。理论分析表明,节理岩体中锚杆的剪切变形过程为:小挠度变形阶段、弹塑性剪切变形阶段、塑性铰阶段;剪切变形至塑性铰阶段时,节理面处杆体将出现两个塑性铰;节理面处锚杆具有一段结构对称、载荷反对称部分;节理宽度对节理处杆体的弹性区、弹塑性区的分界面位置存在线性影响。%The stressing model of anchor bolt in jointed rock mass is established to study the shear deformation mechanism of jointed rock bolts,and the shear deformation at the joints is analyzed theoretically. Relationships between vertical displacement and load,and joint width and material properties of anchor bolt in the vicinity of the joint plane are deducted.The theoretical analysis shows that the shear deformation process of anchor bolt in jointed rock has the following stages,i.e.small deflection deformation stage,elastic -plastic shear deformation stage,and plastic hinge stage.In plastic hinge stage,two plastic hinges will appear on the anchor bolt near the joint plane.The anchor bolt has a section of body of symmetrical structure and anti -symmetrical load near the joint plane.The joint width has linear effect on Interface position between elastic region and elastic-plastic region near the joint.

  17. Study on bolt joint intensity of laminated bamboo for furniture%3种常用螺钉对家具用竹集成材面握钉力的研究

    Institute of Scientific and Technical Information of China (English)

    李吉庆; 陈礼辉; 苏团

    2011-01-01

    以福建省建瓯市所产的毛竹片和低甲醛脲醛树脂胶黏剂为原料,采用正交试验法研究螺钉种类、导孔直径、拧入深度对家具用竹集成材面握钉力的影响.结果表明,螺钉种类对螺钉接合强度影响不显著,其中十字槽沉头自攻螺钉对其影响大些;导孔直径和拧入深度对螺钉接合强度影响显著;减小导孔直径、提高拧入深度能显著提高螺钉接合强度.%The influences of bolt joint factors on joint intensity of laminated bamboo for furniture were studied. The bamboo in Jian' ou City of Fujian Province and low-formaldehyde UF resin were used as main raw materials. Orthogonal design was adopted to analyze the influence of bolt category, diameter of guiding bore and screwing depth. The results showed that bolt joint intensity of laminated bamboo furniture were significantly affected by diameter of guiding bore and screwing depth, and were usually done by bolt category, which cross recessed pan head tapping screws was significantly affected than others. Bolt joint strength of laminated bamboo furniture was obviously increased in usage with the decreasing of diameter of guiding bore and the increasing of screwing depth.

  18. Performance of D-bolts Under Static Loading

    Science.gov (United States)

    Li, Charlie C.

    2012-03-01

    D-bolt is a type of energy-absorbing rock bolt. It is made of a smooth steel bar with anchors spaced along the bolt length. A typical section between adjacent anchors is approximately 1-m long, but it can be adjusted to adapt to the rock conditions. The bolt is fully encapsulated with either cement or resin grout in a borehole. The anchors are firmly fixed into the grout, while the smooth bolt sections can freely deform to absorb deformation energy. Full-scale static pull tests were carried out at different testing facilities in two laboratories. The tests show that a smooth bolt section between anchors may elongate by 110-167 mm depending on the section length. Field trials of the D-bolt were conducted in deep metal mines. The measurements showed that the D-bolts were equally loaded within every anchor-between section, avoiding load peaks and premature bolt failure due to stress concentrations caused by fracture/joint opening. The field trials of rebar and D-bolts in a largely deformed mine tunnel showed that the D-bolts behaved satisfactorily, with only a few failed bolts, while a number of the rebar bolts failed at the thread.

  19. Calculation of mechanical strength of the bolts of the flanged joints of LWR-type reactor pressure vessels (with particular emphasis on the behaviour under critical internal excess pressure, acting like a ''safety valve''). 5. Technical report

    International Nuclear Information System (INIS)

    The reactor pressure vessel has to be made absolutely fail-safe towards excess primary loads (internal pressure). For this purpose, the vessel is equipped with safety valves (e.g. at the pressurizer) which normally are fully sufficient to master any pressure excursion. Nevertheless, a deterministic safety approach requires additional measures to ensure, in case of safety valve failure, control of the pressure so as to prevent reactor pressure vessel bursting. One way to achieve this is to make the flange joints plastify so strongly in the course of a pressure transient that the flange gap will sufficiently widen and thus behave like a 'safety valve'. In order to keep damage as small as possible, these parts should be easy to replace so that the bolts, or rather the washers, seem to be appropriate for modification. Tests have been made to ascertain whether reduction of bolt cross-sectional area (increase in admissible stress), or insertion of suitable washers is the best way to achieve reliable behaviour under normal conditions and also additional function in terms of a safety valve in case of pressure transients. For this purpose, model calculations have been made for all possible flange joints whith all possible stress variations and bolt dimensions. The event simulated is the ATWS', and the strength computations and stress analyses made for the flange joints of the pressure vessel of the Biblis reactor, unit B, are taken as an example. Main attention has been given to the forces affecting the bolts and to the forces acting between the reactor vessel head flange and the vessel flange under internal excess pressure. For assessment of the thermodynamic processes in case of an ATWS, the calculations made for the Grafenrheinfeld reactor have been taken as a basis. (orig.)

  20. Numerical investigation on the position of holes for reducing stress concentration in composite plates with bolted and riveted joints

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper studies the effects of fiber orientaion and holes position on stress concentration and the determination of weakened areas in the composite of glass fiber reinforced epoxy resin around the hole for joints by using the finite element method.In this study,for the observation of areas affected by stress concentration Tsai-Wu failure criterion is used to determine the failed elements and ANSYS Software is implemented for modeling.In order to compare the effect of geometric parameters on stress concen...

  1. Bolt Stress Monitor

    Science.gov (United States)

    1978-01-01

    In photo, an engineer is using a new Ultrasonic Bolt Stress Monitor developed by NASA's Langley Research Center to determine whether a bolt is properly tightened. A highly accurate device, the monitor is an important tool in construction of such structures as pressure vessels, bridges and power plants, wherein precise measurement of the stress on a tightened bolt is critical. Overtightened or undertightened bolts can fail and cause serious industrial accidents or costly equipment break-downs. There are a number of methods for measuring bolt stress. Most widely used and least costly is the torque wrench, which is inherently inaccurate; it does not take into account the friction between nut and bolt, which has an influence on stress. At the other end of the spectrum, there are accurate stress-measuring systems, but they are expensive and not portable. The battery-powered Langley monitor fills a need; it is inexpensive, lightweight, portable and extremely accurate because it is not subject to friction error. Sound waves are transmitted to the bolt and a return signal is received. As the bolt is tightened, it undergoes changes in resonance due to stress, in the manner that a violin string changes tone when it is tightened. The monitor measures the changes in resonance and provides a reading of real stress on the bolt. The device, patented by NASA, has aroused wide interest and a number of firms have applied for licenses to produce it for the commercial market.

  2. Optimization of Bolt Stress

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The state of stress in bolts and nuts with ISO metric thread design is examined and optimized. The assumed failure mode is fatigue so the applied preload and the load amplitude together with the stress concentrations define the connection strength. Maximum stress in the bolt is found at, the fillet...

  3. 带八角垫与双楔角环垫的法兰接头密封性能比较%Comparison of Sealing Performance of Bolted Flange Joints with Octagonal Gasket and Double Tapered Gasket

    Institute of Scientific and Technical Information of China (English)

    荣文波; 陆晓峰; 程可

    2015-01-01

    利用ABAQUS有限元软件对带新型双楔角环垫与带八角垫的螺栓法兰接头进行数值模拟分析,对预紧工况和操作工况下的螺栓与法兰应力最大值、密封面接触压力最大值以及有效密封宽度进行分析对比。结果表明:介质内压使带双楔角环垫的法兰应力最大值下降,但法兰与螺栓应力值仍高于带八角垫的法兰、螺栓应力值;法兰公称直径增加,八角垫内、外侧面的有效密封宽度逐渐减小,而双楔角环垫主、从面有效密封宽度有增大的趋势;双楔角环垫特殊的楔形结构使得主、从面接触应力在介质内压作用后下降幅度小于八角垫内、外侧面,因而具有更好的密封性能,特别是对于大法兰公称直径的密封。%The sealing performances of the bolted flange joints with double tapered gasket and octagonal gasket were an⁃alyzed by finite element software of ABAQUS. The maximum stress between flange and bolt,the maximum contact pressure on each sealing surface and the effective sealing width between two gasket were analyzed and compared under working con⁃ditions and operating conditions. The results show that the internal pressure makes the maximum stress of the flange with double tapered gasket drop, but its stress of flange and bolt is still higher than that of the flange with octagonal gasket. With the increasing of nominal diameter, the effective sealing width of the inside and outside surfaces of octagonal gasket is decreased, but the double tapered gasket shows an increasing trend in the effective sealing width of the master and slave surfaces. The special wedge structure of double tapered gasket makes the decreasing amplitude of contact stress less than the octagonal gasket under internal pressure, therefore double tapered gasket has good sealing performance, especially for the sealing of the flange joints with large nominal diameter.

  4. Dynamic Characteristics Analysis of Bolted Joints Based on Wavelet Analysis%基于小波分析的螺栓联接结构的动态特性分析

    Institute of Scientific and Technical Information of China (English)

    闫航瑞; 曾国英; 赵登峰

    2012-01-01

    Wavelet packet analysis is used to extract the acceleration signals of the bolted joints structure under the peening excitation which contains a natural frequency.The dynamic characteristics which change along with the bolt loose are analyzed by the frequency band signals of that CWT.The experimental system is built based on the Premax data acquisition and analysis equipment Based on the time-frequency characteristic analysis of response signals,the frequency bandwidth of(320~480 )Hz is chosen as the analyzed frequency band and that is restructured. Then, under different connection condition, the time-domain signals within the bandwidth of (320~480)Hz are analyzed by the CWT.The result of the analysis shows that the looseness has a tremendous influence on the dynamic characteristics of the bolted joints structure in the peening vibrational environment, which is ,the smaller the preloading, the faster the signal attenuation, and the greater the structural damping,the more wave energy dissipation,with nonlinear characteristics enhanced.%利用小波包分析技术提取敲击状态下搭接梁螺栓联接结构包含某一固有频率的振动加速度信号,根据该频段信号的连续小波变换(CWT,1-D Continuous Wavelets)分析螺栓联接结构随着预紧力变化的动态特性.首先基于Premax大型数据采集与分析系统搭建实验平台;之后根据振动信号的时频特性选取(320~480)Hz作为分析频段并进行单支重构;然后对不同连接状况下在该频段的时域信号进行一维连续小波变换.分析结果发现螺栓松动变化与其结构的动态特性密切相关,在敲击下,预紧力越小,信号衰减越快,其结构阻尼越大,表示联接结构的能量耗散增大,系统非线性增强.

  5. Manufacture and tests of shape memory actuators for bolted joints of the oil and gas industry; Fabricacao e testes de atuadores de ligas com memoria de forma para unioes aparafusadas do setor de petroleo e gas

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Niedson J. da; Silva, Marcos M. da [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Curso de Pos-graduacao em Ciencia e Engenharia de Materiais; Araujo, Carlos J. de; Santos, Marco A. dos [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia Mecanica

    2008-07-01

    Shape memory alloys (SMA) actuators have a great potential for applications in the engineering field due to the ability of mechanical force generation through the Shape Memory Effect (SME). The SME behavior is the capacity of SMA remember a form established previously when submitted to a temperature variation. In the oil and gas industry there is a variety of possible applications for these active materials, from thermostatic valves to safety devices for piping. Thus, the aim of this work was to study the technical viability of developing SMA washers for potential application in bolted joints of pipelines to improve the reliability of these joints. NiTi SMA washer actuators were produced through casting by plasma skull melting and molding by Push Pull method using the Discovery all machine from EDG equipment and controls. The NiTi SMA washers were obtained and analyzed using electrical resistance and force generation as a function of temperature. The results of force generation as a function of the temperature have demonstrated that important mechanical efforts can be obtained, justifying the application of these SMA for pipeline joints employed in the oil and gas industry. (author)

  6. Modal Experiments and Finite Element Analysis of the Bolted Structure Considering Interface Stiffness and Prtension

    Institute of Scientific and Technical Information of China (English)

    WEI Li-dui; DUAN Shu-lin; WU Ji; WU Qi-li; XING Hui

    2012-01-01

    It is particularly important to evaluate natural frequencies and natural modes of the structure of bolted joints to avoid the failures of the structure due to the resonance. The vibration characteristics of bolted structures are closely connected to surface roughness of contact interfaces, the magnitude of pretension of the bolts and the number of clamping bolts. In this paper, the effect of the factors above on the natural frequencies of bolted structures is sys- tematically investigated by experiments. Then, the finite element method is applied to analyze the effect. Finally, the numerical method is validated by experimental measurements of the natural frequencies.

  7. Numerical Studies on Time-Varying Stiffness of Disk-Drum Type Rotor with Bolt Loosening

    Science.gov (United States)

    Qin, Zhaoye; Chu, Fulei

    2015-07-01

    Disk-drum type rotors are widely used in industry for their high stiffness and low weight properties. In disk-drum type rotors, the adjacent disks and drums are commonly connected by bolted joints. Those rotating joint interfaces are subjected to numerous combinations of loads during normal operation, where loosening of the connecting bolts might occur. The bolt loosening will change the local stiffness of the rotor, which in turn affect the rotor dynamics and even result in structural failures. In this paper, the local stiffness of a disk- drum rotor with bolt loosening is investigated numerically. A three-dimensional (3D) finite element (FE) model for the bolted disk-drum joint is established in ANSYS, where the bolt loosening is simulated by reducing the preloads of certain bolts, and removing those bolts as the limiting case. Simulations are performed on the FE model to evaluate the joint behaviour under static loads. Periodic variations of the joint deflections with respect to the rotation angle of the shaft are obtained, which implies the appearance of the time-varying local stiffness in the rotor system. The studies in this paper help accurate prediction of the rotor dynamics and early detection of bolt loosening.

  8. An investigation into the relation between wheel/rail contact and bolt tightness of rail joints using a dynamic finite element model

    NARCIS (Netherlands)

    Oregui, M.; Li, Z.; Dollevoet, R.P.B.J.

    2012-01-01

    Rail joints have a shorter service life than most other railway track components. The discontinuity between rail ends turns the rail joint into a weak spot, and consequently, into a track component demanding more frequent maintenance measures, which result in high maintenance costs. Moreover, diffic

  9. Turbine casing bolts; a life assessment and bolt replacement strategy

    Energy Technology Data Exchange (ETDEWEB)

    Bulloch, J.H. [ESB, Power Generation, Dublin (Ireland)

    1998-12-31

    The present presentation describes a detailed study concerning the life assessment and replacement strategy of large turbine casing bolts in a 120 MW steam raising unit. After 122000 hours service, circa 1991/92, the Cr-Mo-V steel casing bolts, involving a total of 184 bolts, from two identical 120 MW units, termed Units 1 and 2, were examined to establish the extent of Reverse Temper Embrittlement, RTE, and creep damage suffered during service. The bolt replacement plans for the two units were as follows; Unit 1 bolts were completely replaced with new bolts while Unit 2 embrittled bolts were withdrawn from service and replaced with Non- Embrittled bolts from Unit 1; basically Unit 2 bolts were made up from a mixture of Unit 1 and 2 Non- Embrittled bolts which had been in service for 122000 hours. Remnant life assessments, concerning both embrittlement and creep damage aspects, were earned out on this series of easing bolts at service times 122000, 150000 and 200000 hours. These assessments involved the use of general embrittlement and creep damage laws which were empirically derived and concerned such parameters as microstructural grain size, bulk phosphorus content and accumulated service strain. (orig.) 7 refs.

  10. 基于单体失效的均布螺栓组非等强度连接对传递动力性能的影响分析%An Influence Analysis for Torque Transfer Function Based on Individual Invalidity and Non-equal Strength in an Uniform Set of Bolted Joint

    Institute of Scientific and Technical Information of China (English)

    朱正德

    2011-01-01

    Taking uniform set of bolted joints connected car engines crankshaft flange / fly wheel for example this article introduces a detailed influence analysis about torque transfer function caused individual invalidity in an uniform set of bolted joint. Then it is realizable to make a quantitative assessment of reliability in this case.%论文以连接发动机曲轴法兰/飞轮的均布螺栓组为例,对其中个别螺栓连接由于某种原因引起的失效,将会给整个螺栓组传递扭矩的功能带来的影响进行了详尽的分析,并给出了风险的定量评估.

  11. Preloading of bolted connections in nuclear reactor component supports

    Energy Technology Data Exchange (ETDEWEB)

    Yahr, G T

    1984-10-01

    A number of failures of threaded fasteners in nuclear reactor component supports have been reported. Many of those failures were attributed to stress corrosion cracking. This report discusses how stress corrosion cracking can be avoided in bolting by controlling the maximum bolt preloads so that the sustained stresses in the bolts are below the level required to cause stress corrosion cracking. This is a basic departure from ordinary bolted joint design where the only limits on preload are on the minimum preload. Emphasis is placed on the importance of detailed analysis to determine the acceptable range of preload and the selection of a method for measuring the preload that is sufficiently accurate to ensure that the preload is actually within the acceptable range. Procedures for determining acceptable preload range are given, and the accuracy of various methods of measuring preload is discussed.

  12. Bolt Thread Stress Optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2012-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...

  13. Degradation and failure of bolting in nuclear power plants: Volume 2: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1988-04-01

    A four-year program to resolve the generic safety issue of bolting degradation and failure in nuclear power plants has developed guidelines for material selection, bolting preload control, and plant operation, as well as a realistic method for evaluating the structural integrity of bolted joints. These measures can help improve plant availability while reducing radiation exposure and costs of maintenance and inspection. This report provides the technical basis for resolution of the generic issue of bolting degradation and failure in nuclear power plants.

  14. Autoregressive Model-based Bolted Joints Fault Diagnosis%基于自回归模型的螺纹连接松动诊断

    Institute of Scientific and Technical Information of China (English)

    张言; 曾国英; 赵登峰; 栗明燕

    2012-01-01

    应用自回归模型分析法兰螺纹连接上下壳体的差值信号,进行螺纹连接松动诊断。在螺纹连接模型上,改变某一个螺钉的预紧力,将正常工况下的差值信号作为参考总体,并以此建立AR模型,其他预紧力下的差值信号为待检总体,分别计算参考总体与待检总体之间的Euclide距离和Mahalanobis距离。分析结果表明:基于自回归模型的几何距离是有效的螺纹连接松动指标,可以用于螺纹连接故障诊断。%An autoregressive model-based technique is proposed to detect flange screw-connected joints fault.The AR model can be validated by reference population which is defined as difference signal of normal conditions.The difference signal obtained in other preload conditions is defined as inspection population.The analyses of Euclide distance and Mahalanobis distance between reference population and inspection population indicate that autoregressive model-based geometrical distance is considered as effective index of screw-connected joints fault and it can be used to detect screw-connected joints fault.

  15. A Synthetic Phased Array Surface Acoustic Wave Sensor for Quantifying Bolt Tension

    Directory of Open Access Journals (Sweden)

    Rasim Guldiken

    2012-09-01

    Full Text Available In this paper, we report our findings on implementing a synthetic phased array surface acoustic wave sensor to quantify bolt tension. Maintaining proper bolt tension is important in many fields such as for ensuring safe operation of civil infrastructures. Significant advantages of this relatively simple methodology is its capability to assess bolt tension without any contact with the bolt, thus enabling measurement at inaccessible locations, multiple bolt measurement capability at a time, not requiring data collection during the installation and no calibration requirements. We performed detailed experiments on a custom-built flexible bench-top experimental setup consisting of 1018 steel plate of 12.7 mm (½ in thickness, a 6.4 mm (¼ in grade 8 bolt and a stainless steel washer with 19 mm (¾ in of external diameter. Our results indicate that this method is not only capable of clearly distinguishing properly bolted joints from loosened joints but also capable of quantifying how loose the bolt actually is. We also conducted detailed signal-to-noise (SNR analysis and showed that the SNR value for the entire bolt tension range was sufficient for image reconstruction.

  16. Macro-micro mechanical on joint -grout-bolt interaction in rockmass subjected to shear loading%剪切荷载下岩体结构面-浆体-锚杆相互作用机理宏细观研究

    Institute of Scientific and Technical Information of China (English)

    王刚; 袁康; 蒋宇静; 吴学震

    2015-01-01

    The mechanical behavior of bolted rock joints was researched by using bilinear constitutive model of bolt in virtue of the inner-embed FISH language of PFC based on DEM. Through a variation of the bolt’s elastic modulus and the strength of grout, their influence on macroscopic mechanical response and microscopic mechanical response of anchoring system were studied under the bolt−grout−rock interaction. The results show that there is a clear relationship between the mechanical response of bolted rock joint and the mechanical property of anchoring structures. Macroscopic aspect: the stiffer the bolt the more shear strength of bolted rock joint has. Microscopic aspect: the quantity of cracks in grout and rock increase with the increase of bolt’s stiffness so as to result in more damage to anchoring system. Cracks will appear in the joint and the intersection of bolt and joint initially. With the increase of shear displacement, the cracks in joint will be generated at the place whose compressive contact force is very concentrated while the cracks around the bolt will propagate from the intersection of bolt and joint to the two ends of bolt. Besides, the cracks are mainly concentrated on the compression side. Most of the cracks are tension cracks which are induced by compression among particles. The number of cracks in rock and grout will increase when the strength of grout is much larger or smaller. The cracks are mainly tension cracks which are result from the compression among the particles. When the strength of grout is much smaller, the cracks are mainly concentrated on the rock otherwise the cracks will be mainly distributed in grout. Therefore, the shearing strength of bolted rock joint in macroscopic aspect and the damage of anchoring system resulting from anchoring structure in microscopic aspect should be considered comprehensively while reinforcing jointed rock mass so as to realize the macroscopic-microscopic coupling support. It has a certain

  17. The effect of oxidation on the integrity of bolted structures

    International Nuclear Information System (INIS)

    Oxide growing on mild and low alloy steel components in the high pressure CO2 based coolant of the UK gas cooled nuclear power stations can become porous and continue to grow at the interfaces of structural components even when any interfacial gap has filled with oxide. Because such growth gives rise to a net volume expansion, the adjacent components can be forced apart. Any fastening, such as a weld or bolt, holding them together can then become stressed due to growth of oxide alone, and may sustain mechanical damage. The phenomenon is now well understood and methods of predicting behaviour have been developed and refined over the years to ensure safe and continued plant operation. The basis of such methods is presented for bolted joints, and the way in which joint geometry, environment and mechanical properties of component material influence bolt strain is outlined, with examples. (author)

  18. Finite element analysis of bolted flange connections

    Science.gov (United States)

    Hwang, D. Y.; Stallings, J. M.

    1994-06-01

    A 2-D axisymmetric finite element model and a 3-D solid finite element model of a high pressure bolted flange joint were generated to investigate the stress behaviors. This investigation includes comparisons for axisymmetric loading of both the 2-D and 3-D models, the effects of non-axisymmetric bolt pretensions in the 3-D models, and the differences between 2-D and 3-D models subjected to non-axisymmetric loading. Comparisons indicated differences in von Mises stress up to 12% at various points due to the non-axisymmetric bolt pretensions. Applied bending moments were converted to equivalent axial forces for use in the 2-D model. It was found that the largest von Mises stresses in 3-D model did not occur on the side of the connection where the bending stresses and applied axial stresses were additive. Hence, in the 2-D model where the equivalent axial force (for bending moment) and applied axial forces were added, the 2-D model under estimated the maximum von Mises stress obtained from the 3-D model by 30%.

  19. Rock bolting and pull out test on rebar bolts

    OpenAIRE

    Kristjánsson, Gunnar

    2014-01-01

    Pull out tests were carried out in the laboratory of rock mechanics at Norwegian University of Science and Technology (NTNU) for the purpose of determining the critical embedment length of fully grouted rebar bolts. The 20-mm rebar bolts and the grouting material, “the Rescon Zinc bolt cement” used in the testing are widely used in underground projects in Norway. Different embedment lengths, ranging from 10 cm to 40 cm, were employed in the tests under different water-cement ratios ...

  20. Research on Pin Load Distribution and Joining Strength for Multi-bolt Beveled-lap Composite Joints%复合材料两钉斜削搭接接头钉载分配与连接强度研究

    Institute of Scientific and Technical Information of China (English)

    朱红红; 李成; 何龙; 铁瑛

    2012-01-01

    针对复合材料层合板与斜削金属材料板双搭两钉连接接头,基于有限元分析软件ANSYS技术平台,对7种不同几何参数的连接接头钉载比例进行计算分析,探讨螺栓直径配置及金属板厚度对钉载分配的影响.结果表明,降低靠近层合板加载端螺栓直径有助于改善钉载分配,而提高或降低远离加载端的螺栓直径均无益改善钉载分配,降低接头金属连接板非斜削端厚度有助于优化钉载分配;另对上述接头中等直径螺栓连接的斜削形式和等厚度搭接形式接头进行的损伤累积仿真模拟及静拉伸极限强度计算表明,斜削搭接形式下层合板各角度铺层初始损伤载荷及接头整体最终失效载荷值均高于等厚度搭接,且计算发现,在极限载荷水平下,斜削接头持续保持较等厚度搭接接头钉载分配方面的优势,得出其连接强度的提高与它载荷分配优势从加载初持续到最终失效是分不开的结论.%As to two bolts double lap joints connecting composite laminates with beveled metal plates, the pin load distributions of seven joints of different geometric parameters are calculated and analyzed based on the finite element software ANSYS. The effect of bolt diameters and metal plate thickness on pin load distribution is researched, results show that reducing the diameter of bolt near the loading end and metal plate thickness of non beveled side is good for improving the pin load ratio, whereas increasing or reducing the diameter of bolt away from the loading end is both helpless for optimizing pin load distribution. The simulation of damage accumulation and calculated ultimate strength under static tension load for equal diameter bolted joints above used beveled metal plates and equal thickness ones show that the initial damage load of each laminate layer and joint failure load in beveled lap joints are all higher than that in equal thickness lap joint. And calculation show that

  1. Degradation and failure of bolting in nuclear power plants: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, R.E.

    1988-04-01

    These two volumes provide the documentation for industry resolution of the US Nuclear Regulatory Commission (NRC) generic issue B-29, Degradation and Failure of Bolting in Nuclear Power Plants. The issue was identified as a consequence of concerns about the structural integrity of component supports circa 1980. When bolting integrity became a separate issue in 1982, the utility industry responded by forming a Task Group on Bolting under the aegis of the Atomic Industrial Forum (AIF) and the Materials Properties Council (MPC). The AIF/MPC Task Group on Bolting formulated a comprehensive nineteen-task action plan aimed at resolution of the issue, with implementation of the plan, the responsibility of EPRI and the affected Owner's Groups. EPRI organized a matrix-managed Generic Bolted Joint Integrity Program to carry out the research, with the results reported herein.

  2. Acromioclavicular Joint Dislocation of Types Rockwood Ⅲ, Ⅳ and Ⅴ Treated with Coracoclavicular Bolt Combined with Beak-shoulder Ligament Shif%喙锁螺钉结合喙肩韧带移位治疗Rockwood Ⅲ型、Ⅳ型、Ⅴ型肩锁关节脱位

    Institute of Scientific and Technical Information of China (English)

    谢伟; 郑建平; 黎高明; 吴向科; 傅格深

    2012-01-01

    [目的]探讨喙锁螺钉结合喙肩韧带移位治疗RockwoodⅢ型、Ⅳ型、Ⅴ型肩锁关节脱位的临床疗效.[方法]对32例RockwoodⅢ型、Ⅳ型、Ⅴ型肩锁关节脱位患者采用喙锁螺钉结合喙肩韧带移位治疗,采用Karlasson标准,分析其临床疗效.[结果]术后随访9~21个月,平均13个月,其中A级28例,B级4例,术后均未出现神经血管损伤、螺钉失败等严重并发症.[结论]喙锁螺钉结合喙肩韧带移位是治疗肩锁关节脱位一种有效的治疗方法.%[Objective] To investigate the effects of acromioclavicular joint dislocation of types Rockwood Ⅲ, IV and V treated with coracoclavicular bolt combined with beak-shoulder ligament shift. [Method] Take Karlasson standard to 32 cases, analyse the clinical effect. [Result]Followed up for 9~ 21m after operation, 28 cases were of level A, 4 level B, without nerve or vessel injury or failure bolt or other severe complication. [Conclusion] Coracoclavicular bolt combined with beak-shoulder ligament shift is an effective method for acromioclavicular joint dislocation.

  3. FE-MODELLING OF A CONTACT LAYER BETWEEN ELEMENTS JOINED IN PRELOADED BOLTED CONNECTIONS FOR THE OPERATIONAL CONDITION

    Directory of Open Access Journals (Sweden)

    Rafał Grzejda

    2014-11-01

    Full Text Available Modelling and calculations of a contact layer between elements joined in a preloaded bolted connection for the operational condition are presented. The physical model of the bolted connection is based on a flexible flange element that is joined with a rigid support by means of the no-bolt model (at the assembly stage or the rigid body bolt model (at the operational stage. The contact layer between joined elements is described as the nonlinear Winkler model. The contact joint model considering an experimental normal elastic characteristic is presented. Examples of normal contact pressure and normal contact deformations distributions are contained.

  4. 聚甲酚磺醛栓联合抗宫炎片治疗宫颈糜烂的临床效果观察%The Clinical Effect Observation of Poly Cresol Sulfonated Aldehyde Bolt Joint Kanggongyanpian for the Treatment of Cervical Erosion

    Institute of Scientific and Technical Information of China (English)

    蒋春红

    2015-01-01

    ObjectiveTo analysis the clinical effect of cresol sulfonated aldehyde bolt joint Kanggongyanpian for the treatment of cervical erosion. MethodsOur hospital diagnosis and treatment of 76 cases of patients with as the research object, is divided into observation group and control group, to analyze the curative effect of two groups of patients.Results The results of the study show, total effective rate of observation group was 97.37%, the difference was signiifcant (P<0.05)Conclusion poly cresol sulfonated aldehyde bolt joint Kanggongyanpian of treatment of cervical erosion has good clinical effect.%目的:分析聚甲酚磺醛栓联合抗宫炎片治疗宫颈糜烂的临床效果。方法我院诊治的患者76例作为研究对象,分为观察组与对照组,对两组患者的治疗效果进行分析对比。结果研究结果显示,观察组总有效率为97.37%,差异显著(P<0.05)。结论聚甲酚磺醛栓联合抗宫炎片治疗宫颈糜烂具有良好的临床效果。

  5. Structural Integrity Assessment of High-Strength Anchor Bolt in Nuclear Power Plant based on Fracture Mechanics Concept

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Eunmo; Huh, Namsu [Seoul Nat' l Univ. of Science and Technology, Seoul (Korea, Republic of); Shim, Heejin; Oh, Changkyun; Kim, Hyunsu [KEPCO Engineering and Construction Company, Inc., Yongin (Korea, Republic of)

    2013-07-15

    The failure of a bolted joint owing to stress corrosion cracking (Succ) has been considered one of the most important structural integrity issues in a nuclear power plant. In this study, the failure possibility of bolting, which is used to support the steam generator of a pressurized water reactor, owing to Succ and brittle fracture was evaluated in accordance with guidelines proposed by the Electric Power Research Institute, which are called the Reference Flaw Factor method. For this evaluation, first, detailed finite element stress analyses were conducted to obtain the actual nominal stresses of bolting in which either service loads or bolt preload were considered. Based on these nominal stresses, the structural integrity of bolting was addressed from the viewpoints of Succ and toughness. In addition, the accuracy of the EPRI Reference Flaw Factor for assessing bolting failure was investigated using finite element fracture mechanics analyses.

  6. A Reduced Order Model of Force Displacement Curves for the Failure of Mechanical Bolts in Tension.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Keegan J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brake, Matthew Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry causes issues when generating a mesh of the model. This report will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. The results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.

  7. AN EXPERIMENTAL STUDY ON THE RELAXATION OF BOLTS

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2015-05-01

    Full Text Available Loss of pre-load with time, commonly known as ‘Relaxation’ is an established phenomena. Behaviour of a bolted joint depends upon the pre-load in the bolts in use, not the pre-load introduced by the mechanic. Loss of pre-load is expected due to the many factors such as embedment relaxation, gasket creep, elastic interactions, and vibration loosening or stress relaxation. In a gasketed joint, due to the gasket flexibility, relaxation is always substantial during preliminary passes, as 80 to 100% loss is not uncommon in almost all the bolts, resulting in a dynamic behaviour. Pre-load in a gasketed joint is stabilized and retained to certain extent in the final passes only. In a non-gasketed joint, due to no gasket and no rotation its static behaviour is concluded. This paper highlights the factors affecting the amount of relaxation with time and presents important considerations that can reduce this. Both the short and long term relaxations are recorded and a ‘best fit’ model for relaxation behaviour is derived.

  8. Stud bolt handling equipment for reactor vessel

    International Nuclear Information System (INIS)

    Reactor vessel stud bolt handling equipment includes means for transferring a stud bolt to a carrier from a parking station, or vice versa. Preferably a number of stud bolts are handled simultaneously. The transfer means may include cross arms rotatable about extendable columns, and the equipment is mounted on a mobile base for movement into and out of position. Each carrier comprises a tubular socket and an expandable sleeve to grip a stud bolt. (author)

  9. Real time bolt preload monitoring using piezoceramic transducers and time reversal technique—a numerical study with experimental verification

    Science.gov (United States)

    Parvasi, Seyed Mohammad; Ho, Siu Chun Michael; Kong, Qingzhao; Mousavi, Reza; Song, Gangbing

    2016-08-01

    Bolted joints are ubiquitous structural elements, and form critical connections in mechanical and civil structures. As such, loosened bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of bolted joint connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt connection. Numerical results, backed by experimental results from testing on a bolted connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the bolted connection.

  10. Relaxation behaviour of gasketed joints during assembly using finite element analysis

    Indian Academy of Sciences (India)

    Muhammad Abid; Saad Hussain

    2010-02-01

    Gasketed bolted flange pipe joints are always prone to leakage during operating conditions. Therefore, performance of a gasketed flange joint is very much dependent on the proper joint assembly with proper gasket, proper gasket seating stress and proper pre-loading in the bolts of a joint. For a gasketed flange joint, the two main concerns are the joint strength and the sealing capability. To investigate these, a detailed three-dimensional nonlinear finite element analysis of a gasketed joint is carried out using gasket as a solid plate. Bolt scatter, bolt bending and bolt relaxation are concluded as the main factors affecting the joint’s performance. In addition, the importance of proper bolt tightening sequence, number of passes influence of elastic and elasto-plastic material modelling on joint performance are also presented. A dynamic mode in a gasketed joint is concluded, which is the main reason for its failure.

  11. 硝酸咪康唑栓与阴道冲洗联合治疗复发性外阴阴道假丝酵母感染的临床疗效%Clinical Curative Effect Analysis of Nitric Acid Health Thiazole Microphones and Vagina Washing Joint Bolt on the Treatment of Recurrent Vulvovaginal Candidiasis Candida Yeast Infection

    Institute of Scientific and Technical Information of China (English)

    杨建庆; 张跃

    2013-01-01

    Objective: To study the health thiazole bolt and nitric acid microphones vagina washing joint on the treatment of recurrent vulvovaginal candidiasis candida mycoderma bacteria the treatment effect of the disease. Methods: 252 were our cases of recurrent vulvovaginal candidiasis candida mycoderma bacteria patients average divided into two groups, the observation group using nitric acid health thiazole microphones bolt joint vagina washing method treatment group using clotrimazole suppositories treatment, compared to two groups curative effect. Results: The observation group the cure rate of 91.3%; The control group cure rate was 57.9%. Significant difference (P< 0.05). Conclusion:Mi nitric acid health thiazole bolt and vagina washing joint on the treatment of recurrent vulvovaginal candidiasis candida mycoderma bacteria disease treatment effect is remarkable.%  目的:探讨硝酸咪康唑栓与阴道冲洗联合治疗复发性外阴阴道假丝酵母菌病的治疗效果。方法:将我院2009年3月~2012年6月期间收治的252例复发性外阴阴道假丝酵母菌病患者平均分为两组,对照组患者采用克霉唑栓剂治疗,观察组患者使用硝酸咪康唑栓与阴道冲洗法联合治疗,然后比较两组的临床疗效。结果:观察组的治愈率达91.3%;对照组的治愈率为57.9%。组间差异具有统计学意义(P<0.05)。结论:硝酸咪康唑栓与阴道冲洗联合治疗复发性外阴阴道假丝酵母菌病具有较高的临床疗效。

  12. A study of rock bolting failure modes

    Institute of Scientific and Technical Information of China (English)

    Cao Chen; Jan Nemcik; Ren Ting; Naj Aziz

    2013-01-01

    Rock bolting has advanced rapidly during the past 4 decades due to a better understanding of load transfer mechanisms and advances made in the bolt system technology.Bolts are used as permanent and temporary support systems in tunnelling and mining operations.A review of has indicated that three systems of reinforcement devices have evolved as part of rock bolt and ground anchor while the rock is not generally thought of as being a component of the reinforcement system.A classification of rock bolting reinforcement systems is presented,followed by the fundamental theory of the load transfer mechanism.The failure mode of two phases of rock bolting system is formularised.The failure modes of cable bolting are discussed using a bond strength model as well as an iterative method.Finally,the interfacial shear stress model for ribbed bar is introduced and a closed form solution is obtained using a tri-line stress strain relationship.

  13. Experimental analysis of thread movement in bolted connections due to vibrations

    Science.gov (United States)

    Ramsey, G. ED; Jenkins, Robert C.

    1995-01-01

    This is the final report of research project NAS8-39131 #33 sponsored by NASA's George C. Marshall Space Flight Center (MSFC) and carried out by the Civil Engineering Department of Auburn University (Auburn, Alabama) and personnel of MSFC. The objective of this study was to identify the main design parameters contributing to the loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and a percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration, and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

  14. 卡前列甲酯栓联合葡萄糖酸钙预防宫缩乏力性产后出血的临床观察%Among the bolt joint methyl card calcium gluconate prevention contractions fatigue Sex of postpartum hemorrhage clinical observation

    Institute of Scientific and Technical Information of China (English)

    韩桂芹; 柴光兰; 韩英

    2011-01-01

    目的 研究卡前列甲酯栓联合葡萄糖酸钙在预防产后出血中的临床效果.方法 选择于2009年2月~2010年1月我院住院产妇中,200例在产程中并发宫缩乏力的产妇进性随机分组,观察组100例,胎儿娩出后,立即直肠内放置卡前列甲脂栓,同时静脉推注10%葡萄糖酸钙10ml+5%葡萄糖10ml,缓慢静推;对照组100,胎儿娩出后,立即行缩宫素20μ稀释后静推配合按压子宫.观察两组产妇产后2h内阴道流血量、24h产后出血、第三产程时间及用药后不良反应.结果 卡前列甲酯栓联合葡萄糖酸钙组产后.2h内阴道流量、第三产程时间、产后24h血量均明显少于对照组,差异有显著性(P<0.01),应用卡前列甲酯栓前后血压无变化,无严重不良反应.结论 卡前列甲酯栓联合10%葡萄糖酸钙预防宫索乏力性产后出血安全、有效,是预防产后出血的理想药物.%Objective: To study the bolt joint methyl forefront card calcium gluconate in preventing the clinical effect of postpartum hemorrhage.Methods: Select in February 2009 -2010, our mothers in January, 200 cases were complicated contractions in the lack of maternal into sexual randomized, 100 cases of fetal childbirth, immediately after rectum placed among the card, a fat tethered to inject 10% calcium gluconate 10ml + 5% 10ml glucose slowly, static, Group of 100, fetal childbirth, do 20μ oxytocin immediately after diluted with static push press the uterus.Two groups of maternal postpartum 2h observed within 24 hours, vaginal bleeding amount, the third postpartum hemorrhage and medicine were after the adverse reactions.Results: Among the bolt joint card methyl calcium gluconste group, 2h vaginal discharge postpartum within the third time, postpartum were, are obviously less than 24 hours,the blood control greup ( P < 0.01 ), the application of methyl forefront card and change, blood bolt no serious adverse reactions.Conclusion: The card top 10% of methyl

  15. Ballistics Analysis of Orion Crew Module Separation Bolt Cover

    Science.gov (United States)

    Howard, Samuel A.; Konno, Kevin E.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    NASA is currently developing a new crew module to replace capabilities of the retired Space Shuttles and to provide a crewed vehicle for exploring beyond low earth orbit. The crew module is a capsule-type design, which is designed to separate from the launch vehicle during launch ascent once the launch vehicle fuel is expended. The separation is achieved using pyrotechnic separation bolts, wherein a section of the bolt is propelled clear of the joint at high velocity by an explosive charge. The resulting projectile must be contained within the fairing structure by a containment plate. This paper describes an analytical effort completed to augment testing of various containment plate materials and thicknesses. The results help guide the design and have potential benefit for future similar applications.

  16. Removable Type Expansion Bolt Innovative Design

    Science.gov (United States)

    Wang, Feng-Lan; Zhang, Bo; Gao, Bo; Liu, Yan-Xin; Gao, Bo

    2016-05-01

    Expansion bolt is a kind of the most common things in our daily life. Currently, there are many kinds of expansion bolts in the market. However, they have some shortcomings that mainly contain underuse and unremovement but our innovation of design makes up for these shortcomings very well. Principle of working follows this: expansion tube is fixed outside of bolt, steel balls and expansion covers are fixed inside. Meanwhile, the steel balls have 120° with each other. When using it ,expansion cover is moved in the direction of its internal part. So the front part of expansion bolt cover is increasingly becoming big and steel halls is moved outside. Only in this way can it be fixed that steel balls make expansion tube expand. When removing them, expansion bolt is moved outside. So the front part of expansion bolt cover is gradually becoming small and steel balls moves inside, after expansion tube shrinks, we can detach them.

  17. Plug and play type joints in steel and steel-concrete composite constructions

    NARCIS (Netherlands)

    Bijlaard, F.S.K.; Brekelmans, J.W.P.M.

    2007-01-01

    Traditionally for Western Europe countries, joints in steel frame structures are realised using bolts and welds. In the workshop the components are made using welding and drilling of the bolt holes. On site these structural components are connected together using bolts and nuts. The actions on site

  18. The new structure of fibre glass reinforced plastics bolt

    Institute of Scientific and Technical Information of China (English)

    马念杰; 刘社育

    2003-01-01

    The develop actuality and direction of FRP(fibre glass reinforced plastics) bolt in the world are analyzed. The new type structure of FRP bolt was designed. Trial data indicate that, all kinds of capability target of this FRP bolt all achieve and exceed the country standard, substitute present metal bolt,wood bolt and bamboo bolt and other side bolt, it can gain magnitude technology and economy benefit. FRP bolt mechanization product line produce efficiency is high, its throughput a day are 750 base, this can meet demand of hit-small mining company.

  19. Loosening and Sliding Behaviour of Bolt-Nut Fastener under Transverse Loading

    Directory of Open Access Journals (Sweden)

    Naruse T.

    2010-06-01

    Full Text Available The thread joint has been frequently used for the efficient productivity and maintainability as a machine element. However, many troubles such as loosening of bolted joints or fatigue failure of bolt were often experienced. Many attentions must be paid on the improvement of the strength and the reliability of the thread joints [1, 2]. It is generally said that the fastening axial force rapidly decreases by the rotation loosening of nuts if the relative slippage on the interfaces between nuts and fastened body goes beyond a certain critical limit [3]. This critical relative slippage (Scr that prescribes the upper limit for preventing the loosening behaviour has been estimated according to the theoretically obtained equation considering the bending deformation of bolt and the geometrical constraint condition. In this paper, firstly we present the equation for estimating the Scr based on the fundamental cantilever deformation model. Then we present the investigated results of the deformation behaviour of bolt-nut joint under transverse loading condition considering the reaction moment by nut (Mn. Finaly we can confirmed that these estimated results of critical relative slippage coincided well with the experimental results [4, 5].

  20. Stiffness Measurement Method of Turning Center Acted by Auto-displacing Full Load and Bolt Joint Design Apply%自变位全载荷下车削中心刚度检测及螺栓结合部设计应用

    Institute of Scientific and Technical Information of China (English)

    惠烨; 黄玉美; 杨新刚; 李艳

    2014-01-01

    为了实现对数控车削中心主轴箱刚度准确评价及给主轴箱结构改进方案提供负载下刚度检测依据,深入研究全载荷加载装置的加载原理,提出自动变位全载荷下车削中心主轴箱静刚度检测方法,研制全载荷加载装置,应用自动变位全载荷加载装置对车削中心施加载荷进行主轴箱静刚度检测试验;采用有限元法计算全载荷下车削中心主轴箱的静刚度及刚度分布,分析了主轴箱的刚度分布特点;在试验和有限元分析的基础上改进了主轴箱结构的设计方案,修改主轴箱与床身连接的螺栓结合部,使主轴箱静刚度得以提高;通过将改进前后的试验结果与有限元分析进行对比,验证了试验方法的正确性以及基于螺栓结合部的改进方案的有效性。%In order to evaluate stiffness state of the headstock for CNC turning centers accurately, which can provide the modifying suggestions for improvement structural scheme of the headstock, based on thorough investigation of loading theory of full loading device, static stiffness measurement method acted by auto-displacing full load is proposed, in which the static stiffness of the headstock is detected by the self-developed automatic displacement simulate full load loading device. The stiffness and its distribution of turning center’s headstock is analyzed with finite element method (FEM). According to results of the static stiffness measuring experiment and computing fruits with FEM, the structural schema of the headstock is improved by revising the bolt joint between the headstock and the bed, which enhances the static stiffness of the headstock. By comparing FEM analysis with the experimental results of pre- and post structural improvement, the correctness of the measuring method of static stiffness and the effectiveness of improved structural scheme with bolt joint are verified.

  1. Parametric study on the axial performance of a fully grouted cable bolt with a new pull-out test

    Institute of Scientific and Technical Information of China (English)

    Chen Jianhang⇑; Hagan Paul C.; Saydam Serkan

    2016-01-01

    Modified cable bolts are commonly used in underground mines due to their superior performance in pre-venting bed separation when compared with plain strands. To better test the axial performance of a wide range of cable bolts, a new laboratory short encapsulation pull test (LSEPT) facility was developed. The facility simulates the interaction between cable bolts and surrounding rock mass, using artificial rock cylinders with a diameter of 300 mm in which the cable bolt is grouted. Furthermore, the joint where the load is applied is left unconstrained to allow shear slippage at the cable/grout or grout/rock interface. Based on this apparatus, a series of pull tests were undertaken using the MW9 modified bulb cable bolt. Various parameters including embedment length, test material strength and borehole size were evalu-ated. It was found that within a limited range of 360 mm, there is a linear relationship between the max-imum bearing capacity of the cable bolt and embedment length. Beyond 360 mm, the peak capacity continues to rise but with a much lower slope. When the MW9 cable bolt was grouted in a weak test material, failure always took place along the grout/rock interface. Interestingly, increasing the borehole diameter from 42 to 52 m in weak test material altered the failure mode from grout/rock interface to cable/grout interface and improved the performance in terms of both peak and residual capacity.

  2. 21 CFR 137.280 - Bolted yellow corn meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  3. Assessment of rock bolt systems for underground waste storage

    International Nuclear Information System (INIS)

    A review of existing rock bolting systems was undertaken to assess their suitability in underground design for storage of nuclear waste. Unique engineering considerations are required due to the thermal pulse generated by the waste causing additional stress to the support system and possibly affecting anchorage stability. Field visits were made to four underground projects to assess the performance of a wide variety of rock bolt systems. Cable bolts, point anchor bolts, locally debonded full column cement grout bolts, and yieldable bolt systems show promise. Full scale testing of bolt systems is recommended, together with assessing temperature effects on grout strength and grout longterm stability

  4. An Investigation on Load Bearing Capacities of Cement and Resin Grouted Rock Bolts Installed in Weak Rocks

    Science.gov (United States)

    Kalyoncu Erguler, Guzide; Abiddin Erguler, Zeynal

    2015-04-01

    Rock bolts have been considered one of indispensable support method to improve load bearing capacity of many underground engineering projects, and thus, various types of them have been developed until now for different purposes. Although mechanically anchored rock bolts can be successfully installed to prevent structurally controlled instabilities in hard rocks, in comparison with cement and resin grouted rock bolts, these types of anchors are not so effective in weak rocks characterized by relatively low mechanical properties. In order to investigate the applicability and to measure relative performance of cement and resin grouted rock bolts into weak and heavily jointed rock mass, a research program mainly consisting of pull-out tests was performed in a metal mine in Turkey. The rock materials excavated in this underground mining were described as basalt, tuff, ore dominated volcanic rocks and dacite. To achieve more representative results for rock materials found in this mining and openings excavated in varied dimensions, the pull-out tests were conducted on rock bolts used in many different locations where more convergences were measured and deformation dependent instability was expected to cause greater engineering problems. It is well known that the capacity of rock bolts depends on the length, diameter and density of the bolt pattern, and so considering the thickness of plastic zone in the studied openings, the length and diameter of rock bolts were taken as 2.4 m. and 25 mm., respectively. The spacing between rows changed between 70 and 180 cm. In this study, totally twenty five pull-out tests were performed to have a general understanding about axial load bearing capacity and support reaction curves of cement and resin grouted rock bolts. When pull load-displacement curves belongs to cement and resin grouted rock bolts were compared with each other, it was determined that cement grouted rock bolts carry more load ranging between 115.6 kN and 127.5 kN with

  5. ANCHORING EFFECT ANALYSIS OF TENSIONED BOLTS

    Institute of Scientific and Technical Information of China (English)

    夏建中

    1997-01-01

    The paper analyses quantitatively the anchoring effect of tensioned bolts on surrounding rock strength, and defines two concepts: one is the surrounding rock strength increased amount △τ13 and the other is the strength influence factor k. The anchoring effect of tensioned bolts is considered to increase a strength increased amount △τ13 where △τ13 is the product k and tensioned load p, i. e. △τ13= kp, where k is a function of two variables x and y. The distributive properties both △τ13 and k are also discussed in the paper, obtaining some useful results for designing bolting support parameters.

  6. Study on the material character steel big-end bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie; ZHAN Ping; ZHANG Dian-li

    2008-01-01

    Based on the manufacturing method now used in our country, caused low bear-ing capacity in the bolt-end, which is a potential danger in the bolt supporting tunnel and a waste of money, and presented the new type strong steel big-end bolt can solve this problem. Analyzed the active state of the end of bolt by ANSYS, we can know that it is very disadvantage when bolt bore eccentric load. Contrasted with the different that com-mon bolt and big-end bolt when they bore the same loading. The common bolt is bigger than the big-end bolt in stress value. Study on the processing technic of the new type of the strong steel big-end bolt, the new metal big-end bolt was produced by heat processing over big-end bolt and upset. From the microscopic examination on bolt metal, it is con-cluded that heat processing on the bolt-end refines the crystal grain of the metal material, which not only increase its extension but improve its property. Moreover the strength ability of the bolt material can be exerted completely.

  7. Study on the material character steel big-end bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie; ZHAN Ping; ZHANG Dian-li

    2008-01-01

    Based on the manufacturing method now used in our country,caused low bearing capacity in the bolt-end,which is a potential danger in the bolt supporting tunnel and a waste of money,and presented the new type strong steel big-end bolt can solve this problem.Analyzed the active state of the end of bolt by ANSYS,we can know that it is very disadvantage when bolt bore eccentric load.Contrasted with the different that common bolt and big-end bolt when they bore the same loading.The common bolt is bigger than the big-end bolt in stress value.Study on the processing technic of the new type of the strong steel big-end bolt,the new metal big-end bolt was produced by heat processing over big-end bolt and upset.From the microscopic examination on bolt metal,it is concluded that heat processing on the bolt-end refines the crystal grain of the metal material,which not only increase its extension but improve its property.Moreover the strength ability of the bolt material can be exerted completely.

  8. Computerized UT system for stud bolt

    International Nuclear Information System (INIS)

    Cracking of stud bolts used in steam turbine casing, valve and pressure vessel has caused concern regarding the safety and reliability of power plants. In order to detect harmful cracks in early state, the improvement of UT technique is required. As regarding the ultrasonic inspection technique, a longitudinal beam technique and/or an angle beam technique are generally used. The authors report their development of a computerized UT system for bolt inspection and improvement of the angle beam technique

  9. Research on the bolt supporting principal of developing entry

    Institute of Scientific and Technical Information of China (English)

    XIONG Ren-qin

    2004-01-01

    Based on the principle of rock-soil mechanics, the bolt supporting technology of mine roadway were researched, it is pointed out that the roadway's four corner bolt, the prestressed bolt and the extensible bolt play an important role in keeping road stable; it is also indicated that the walls of roadway safeguarded well is important in keeping road stable, which can make the bolt and surrounding rock load-bearing together; bolt and grounting technology can increase anchorage capacity, which is very applicable for soft rock supporting and developing entry.

  10. Bolted join strength under parallel to grain double shear in guadua angustifolia structures

    Directory of Open Access Journals (Sweden)

    Fabián Augusto Lamus Báez

    2014-01-01

    Full Text Available In a bolted joint of structures that use Guadua angustifolia as the main supporting material, the resistance to the double metal shears paralleled to fiber could be influenced by an extensive list of parameters including parallel to fiber crushing resistance, parallel to metal fiber resistance of the wall and the contact area between elements in the joint. This paper presents experimental results for the resistance to the double metal shears paralleled to fiber, when the element is loaded under compression, for different culm diameters. Moreover, we studied the influence of the bolt diameter and culm thickness in the joint resistance. The tests were conducted on specimens of Guadua angustifolia with variable diameters between seven and fourteen centimeter where bolts of 3/8, 1/2 and 3/4" diameter were used. The Guadua tested came from the outskirts of Armenia in Colombia. It was found that the great amount of the double metal shears paralleled to fiber in the joint is provided by parallel to fiber crushing resistance of the Guadua.

  11. Analysis of the influence of joint characteristic parameters on roadway deformations

    Institute of Scientific and Technical Information of China (English)

    WANG Tong-xu; WANG Wen-bin; JIANG Li-yan; ZHANG Zhen-yu

    2007-01-01

    By means of numerical simulation, the roadway deformation affected by joints was analyzed and the pre-tensioned bolts for reinforcing roadway roof in jointed rock mass was studied. The results show that the roadway roof deformation increases gradually with the accretion of joint length, the increase of joint number, the de- crease of intervals, angles and friction angles of joints. The increase is obvious at beginning and then tends slowly. After pre-tensioned bolts are used, roadway roof deformations reduce obviously,and the supporting action of pre-tensioned bolts is more remarkable with accretion of joint length, increasing of joint number, reducing of joint interval, decreasing of joints angle and joint friction angle, and increasing of joint number that bolts drilling through. With comparison of different cases, the joints supporting effect is more remarkable at a small angel.It indicates that the supporting mechanism of pre-tensioned bolts is to reinforce weak faces, such as joints. The more joints the roof includes, the more visible the pre-tensioned bolts strengthening effect is.

  12. More Nuts and Bolts of Michaelis-Menten Enzyme Kinetics

    Science.gov (United States)

    Lechner, Joseph H.

    2011-01-01

    Several additions to a classroom activity are proposed in which an "enzyme" (the student) converts "substrates" (nut-bolt assemblies) into "products" (separated nuts and bolts) by unscrewing them. (Contains 1 table.)

  13. High-Strength Bolt Corrosion Fatigue Life Model and Application

    Directory of Open Access Journals (Sweden)

    Wang Hui-li

    2014-01-01

    Full Text Available The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life.

  14. Rock bolt mechanical analysis and its application to engineering

    Institute of Scientific and Technical Information of China (English)

    GUO Ling-yun; XIAO Ming; XIAO Ying-chun

    2008-01-01

    Combined with the 3D FEM, end-anchored anchorage bolts were simulated by implicit anchorage bolt element. Implicit anchorage bolt elements hide in the elements of rock mass and extremely simplify the element subdivision. The calculated value of an-chorage bolt stress is larger than the measured one for the most time. we further analyzed the reciprocity of anchorage bolt and rock mass, and then deduced the analytical equa-tions of anchorage bolt stress and rock mass deformation under elasto-plastic state. The results indicate that it is essential to revise the anchorage bolts stress by using the formu-las deduced when rock mass is softened or significantly deformed. Finally, a case study indicates that the calculated results agree with those measured. Some helpful methods are offerd for more accurate simulation of the support effect and anchorage bolts real stress state.

  15. Tension-loaded bolted connections in steel structures

    OpenAIRE

    Skavhaug, Elin Stensrud; Østhus, Svanhild Irene

    2015-01-01

    The purpose of this thesis is to study the behaviour of bolted steel connections subjected to tension. Quasi-static conditions have been considered. By performing laboratory tests on single bolts and simple T-stub connections the failure modes of the bolts have been examined. Finite element models are created and validated to represent the behaviour observed in the laboratory. Different grip length configurations have been tested for a single bolt and nut assembly subjected to pure tensio...

  16. 21 CFR 137.255 - Bolted white corn meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food... of the finished bolted white corn meal does not exceed by more than 0.3 percent the fat content...

  17. Stress wave propagation in supporting bolts: A test for bolt support quality

    Institute of Scientific and Technical Information of China (English)

    Wu Rui; Xu Jinhai; Li Chong; Zhou Baojing; Ma Qianqian; Wang Zhongliang

    2012-01-01

    A test method for the non-destructive determination of bolt length,anchoring length,and bolt body force is described.This addresses the problems of low accuracy,limited number of data,and untimely warning signs encountered with existing test methods.Numerical simulations of the bolt,resin,and rock system show that the length accuracy when using the velocity wave is lower than when using the acceleration wave.It is accepted practice to use the acceleration wave for length tests because of improved signal to noise ratios of the waveforms.Laboratory and in situ underground tests showed that the precision of the measurements meets field requirements.Using this method the anchor properties of each single bolt and,thus,the safety of the entire roadway support may be evaluated.

  18. Investigation of Reliabilities of Bolt Distances for Bolted Structural Steel Connections by Monte Carlo Simulation Method

    Directory of Open Access Journals (Sweden)

    Ertekin Öztekin Öztekin

    2015-12-01

    Full Text Available Design of the distance of bolts to each other and design of the distance of bolts to the edge of connection plates are made based on minimum and maximum boundary values proposed by structural codes. In this study, reliabilities of those distances were investigated. For this purpose, loading types, bolt types and plate thicknesses were taken as variable parameters. Monte Carlo Simulation (MCS method was used in the reliability computations performed for all combination of those parameters. At the end of study, all reliability index values for all those distances were presented in graphics and tables. Results obtained from this study compared with the values proposed by some structural codes and finally some evaluations were made about those comparisons. Finally, It was emphasized in the end of study that, it would be incorrect of the usage of the same bolt distances in the both traditional designs and the higher reliability level designs.

  19. Inedible Nuts and Non-Lightning Bolts

    Science.gov (United States)

    Rynone, William

    2010-01-01

    In this article, the author provides detailed information on a wide variety of commonly used screws, bolts, and other fasteners. The information has been gathered in his engineering career and outside interests (maintenance on his car and airplane, and woodworking). The topic should be of interest to students and educators in many technical…

  20. Parameters determination and bolting control of gateway floor

    Institute of Scientific and Technical Information of China (English)

    GOU Pan-feng; XlN Ya-jun

    2011-01-01

    Gateway floor heave control is the key to guarantee mine safe and efficient production.Through analysis of floor instability characteristics and bolting control,gateway floor strata show second level stress under abutment pressure,which causes plastic flow failure in floor strata; gateway floor instability shows mainly shear-break slippage of “triangle sliding body”.Mechanics of floor bolting is mainly a function of connection and combination.Main area of bolting control lies in two gateway floor angles.The paper analyzes mechanics principle of gateway floor instability,constructs stability mechanics model of gateway floor bolting,obtains gateway floor stability criterion of different bolting angles and optimum formula of bolting parameters,carries out the engineering example,and guides better field application.It provides theoretical base for bolting gateway floor instability control.

  1. Bolting Cabin Assistance System Using a Sensor Network

    Directory of Open Access Journals (Sweden)

    Yung-Hak Mo

    2012-10-01

    Full Text Available The bolting cabin assistance system prevents operators from facing dangerous situations. This system consists of a bolting robot control system and a top view supervisory system. In order to control the bolting robot, circular Hough transforms and fuzzy reasoning are used. First, the circular Hough transform roughly estimates the location of the bolt hole. After that, errors of estimation are compensated for using fuzzy reasoning. In order to track a bolt hole, a region of interest (ROI is used. By setting the region in which to search for a bolt hole, the algorithm tracks the location of the bolt hole. In order to choose an ROI, a template‐based matching algorithm is used. In order to make the top view supervisory system, four cameras are installed at the left, right, front and back of the robot. The four individual images from the various cameras are combined to make the top view image after correcting for distortion.

  2. Analysis of mechanical joint in composite cylinder

    Science.gov (United States)

    Hong, C. S.; Kim, Y. W.; Park, J. S.

    Joining techniques of composite materials are of great interest in cylindrical structures as the application of composites is widely used for weight-sensitive structures. Little information for the mechanical fastening joint of the laminated shell structure is available in the literature. In this study, a finite element program, which was based on the first order shear deformation theory, was developed for the analysis of the mechanical joint in the laminated composite structure. The failure of the mechanical fastening joint for the laminated graphite/epoxy cylinder subject to internal pressure was analyzed by using the developed program. Modeling of the bolt head in the composite cylinder was studied, and the effect of steel reinforcement outside the composite cylinder on the failure was investigated. The stress component near the bolt head was influenced by the size of the bolt head. The failure load and the failure mode were dependent on the bolt diameter, the number of bolts, and fiber orientation. The failure load was constant when the edge distance exceeds three times the bolt diameter.

  3. Analysis of WWER 440 SG primary collector bolted joint damage

    Energy Technology Data Exchange (ETDEWEB)

    Matocha, K.; Wozniak, J. [Vitkovice J.S.C., Ostrava (Switzerland); Pochman, K. [NPP Dukovany (Switzerland)

    1997-12-31

    The susceptibility of CHN35VT-VD and 08CH18N10T stainless steels to stress corrosion cracking in water environment, simulating water solution found in threaded holes, was investigated using rising load line displacement tests of precracked C(T) specimens. To judge the role of oxidant on stress corrosion cracking of both stainless steels, the effect of dissolved oxygen content (fully deaerated water, water aerated at the beginning of the test) was studied. 7 refs.

  4. The design and testing of subscale smart aircraft wing bolts

    International Nuclear Information System (INIS)

    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers. (paper)

  5. The design and testing of subscale smart aircraft wing bolts

    Science.gov (United States)

    Vugampore, J. M. V.; Bemont, C.

    2012-07-01

    Presently costly periodic inspection is vital in guaranteeing the structural integrity of aircraft. This investigation assesses the potential for significantly reducing aircraft maintenance costs without modification of aircraft structures by implementing smart wing bolts, manufactured from TRIP steel, which can be monitored for damage in situ. TRIP steels undergo a transformation from paramagnetic austenite to ferromagnetic martensite during deformation. Subscale smart aircraft wing bolts were manufactured from hot rolled TRIP steel. These wing bolts were used to demonstrate that washers incorporating embedded inductance coils can be utilized to measure the martensitic transformation occurring in the TRIP steel during bolt deformation. Early in situ warning of a critical bolt stress level was thereby facilitated, potentially reducing the costly requirement for periodic wing bolt removal and inspection. The hot rolled TRIP steels that were utilized in these subscale bolts do not however exhibit the mechanical properties required of wing bolt material. Thus warm rolled TRIP steel alloys were also investigated. The mechanical properties of the best warm rolled TRIP steel alloy tested almost matched those of AISI 4340. The warm rolled alloys were also shown to exhibit transformation before yield, allowing for earlier warning when overload occurs. Further work will be required relating to fatigue crack detection, environmental temperature fluctuation and more thorough material characterization. However, present results show that in situ early detection of wing bolt overload is feasible via the use of high alloy warm rolled TRIP steel wing bolts in combination with inductive sensor embedded washers.

  6. Optimization of bolt thread stress concentrations

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in the present paper. Thread root design controls the stress concentration...... factor of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element formulation is used to analyze the bolted connection......, and a study is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities...

  7. Combined and interactive effects of interference fit and preloads on composite joints

    Institute of Scientific and Technical Information of China (English)

    Liu Longquan; Zhang Junqi; Chen Kunkun; Wang Hai

    2014-01-01

    The combined and interactive effects of the bolt-hole fit conditions and the preloads of the fasteners on the load carrying capacity of single-lap composite-to-titanium bolted joints have been investigated both experimentally and numerically. Quasi-static tests of the hybrid joints with different fit conditions are implemented, and a three dimensional finite element progressive failure analysis model is proposed to predict the influences of the bolt-hole fit conditions and fastener’s pre-loads on the mechanical behaviors of the joints. Based on the experimental validated simulation method, a multi-factor, mixed levels orthogonal design table and the analysis of variance method are used to arrange the simulation conditions and to further study the interactive effects of preloads and fit conditions. Through the analysis of the results, for the researched double bolt, single-lap composite-titanium joints, it is found that:the effects of both the interference fit and the preloads change from positive into negative mode with the increase of the interference fit values or preload values; appropriate bolt-hole fit conditions and preloads can improve the bolt-hole contact conditions of the loaded joints, and then retard the fiber failures around the fastener holes, and increase the load carrying capacity of the joints eventually; the interactive effect of the bolt-hole interference fit conditions and preloads cannot be ignored and the parameters need to be considered together and synthetically as the joints are being optimized.

  8. Characteristic Evaluation on Bolt Stress by Ultrasonic Nondestructive Methods

    Directory of Open Access Journals (Sweden)

    Qinxue Pan

    2015-01-01

    Full Text Available Based on the acoustoelasticity theory, a certain relationship exists between ultrasonic velocity and stress. By combining shear and longitudinal waves, this paper provides a nondestructive method of evaluating axial stress in a tightened bolt. For measuring the bolt axial stress in different situations, such as under low or high loads, this paper provides guidelines for calculating the stress for a given load factor. Experimental and calculated results were compared for three bolt test samples: an austenitic stainless steel bolt (A2-70 and low-carbon steel 4.8 and 8.8 bolts. On average, the experimental results were in good agreement with those obtained through calculations, thus providing a nondestructive method for bolt stress measurements.

  9. A marketing plan for Lightning Bolt

    OpenAIRE

    Silveira, Filipa Borges

    2013-01-01

    This project had as main goal to improve the perception of male surfers about the surf brand Lightning Bolt. It was proposed the creation of a collection of wetsuits as well as the “A Pure Source” Project to show the commitment of the brand with the surf community. To promote both several promotional activities are suggested such as the use of magazines, radio, banners and social media. To complement the distribution chain of the brand, a concept store and a mobile store are also recommended....

  10. Structural analysis of closure bolts for shipping casks

    Energy Technology Data Exchange (ETDEWEB)

    Mok, G.C.; Fischer, L.E.

    1993-04-01

    This paper identifies the active forces and moments in a closure bolt of a shipping cask. It examines the interactions of these forces/moments and suggest simplified methods for their analysis. The paper also evaluates the role that the forces and moments play in the structure integrity of the closure bolt and recommends stress limits and desirable practices to ensure its integrity.

  11. 9 CFR 313.15 - Mechanical; captive bolt.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Mechanical; captive bolt. 313.15 Section 313.15 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... INSPECTION AND CERTIFICATION HUMANE SLAUGHTER OF LIVESTOCK § 313.15 Mechanical; captive bolt....

  12. Stiffness Analysis and Improvement of Bolt-Plate Contact Assemblies

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Pedersen, Pauli

    2008-01-01

    of stiffnesses is extended to include different material parameters by including the influence of Poisson's ratio. Two simple practical formulas are suggested and their accuracies are documented for different bolts and different material (Poisson's ratio). Secondly, the contact analysis between the bolt head...

  13. Research on Torque Loading Technology Based on L Lever in Spacecraft Bolt

    Directory of Open Access Journals (Sweden)

    Song Xiaohui

    2015-01-01

    Full Text Available As the main form of structure assembly, the stability of bolt joint is directly related to the performance of spacecraft. This essay is used to analyze the cause of standard torque spanner which is not suitable to the tightening torque and summarized according to different operating conditions. Based on thorough analysis of fastening principles and principle of type serialization, a scheme of integrated L Lever is established. The results of experimentation indicate that the scheme of integrated L Lever is reasonable along with the requirement of developing long-life and high-reliability spacecraft. Therefore, the stability of fasteners is greatly enhanced.

  14. Research on the mechanical property test of a new high-strength metal bolt

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-jun; MA Nian-jie

    2011-01-01

    In order to study how to improve the overall performance of the operational metal bolt,based on the production process of an ordinary metal bolt used in understructure engineering,this paper focused on the existing problems of ordinary metal bolts identified by some survey and analysis.The results show that the structure of operational metal bolts is so unreasonable that the bolt tail is easily fractured by low load capacity.Furthermore,a new type of strong big-end metal bolt and its heat treatment and roughing processing technology were introduced.Through bolt tensile and metallographic tests,the property of the new big-end bolt was analyzed.The new findings indicate that after a special processing,the overall strength and plasticity of the bolt is greatly improved,and the grain of the bolt tail structure is refined,which would help build up favorable working conditions for bolt tails.

  15. Factors Influencing the Quality of Encapsulation in Rock Bolting

    Science.gov (United States)

    Aziz, Naj; Craig, Peter; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-08-01

    Bolt installation quality is influenced by various factors, some are well known and others are less recognised. A programme of field and laboratory studies was undertaken to examine various factors of relevance to the load transfer mechanism between the bolt, resin and rock to ensure test methods truly represent field performance. Short encapsulation tests were undertaken as part of the Australian Coal Association Research Program (ACARP) funded project (C21011) with the ultimate aim of developing standard test methods for assessing bolt encapsulation with chemical resin anchor installations. The field study consisted of a series of Short Encapsulation Pull Tests (SEPT) carried out in three mines with different geological conditions to determine the most representative and practical method of SEPT. Additional field work included installation of bolts into threaded steel tubes for subsequent removal and laboratory evaluation. A series of pull tests was carried out by installing bolts in overhead rig mounted sandstone block, cast in concrete with controlled encapsulation length. Factors of importance considered included; borehole diameter, resin annulus thickness, installation time (including bolt spin to the back and "spin at back"), the effect of gloving and hole over drill. It was found that the borehole diameter had a detrimental effect on the encapsulation bonding strength. Bolt installation time of approximately 10 s constituted an acceptable time for effective bolt installation and within the resin manufacturers recommended time of 14 s. Maintaining constant length of encapsulation was paramount for obtaining consistency and repeatability of the test results. Finally, a numerical simulation study was carried out to assess the capabilities of FLAC 2D software in simulating the pull testing of rock bolts.

  16. Richard H. Bolt-Mentor and colleague

    Science.gov (United States)

    Wetherill, Ewart A.

    2003-04-01

    Of his many accomplishments in acoustics, perhaps one of Richard H. Bolt's greatest legacies will prove to be his contribution, both directly and through his teaching, to everyday hearing conditions in buildings. In a discipline that attempts to bridge the technical and cultural gap between a pure science and the pragmatic and often-haphazard process of building design, he combined a deep understanding of both professions with an ability to communicate complex ideas that is reminiscent of Wallace Clement Sabine. His welcoming enthusiasm and humility enabled him to attract and to work well with people of complementary talents, in both theoretical research and the gritty details of a consulting practice, as well as to envision the potential of still-unexplored subjects. A logical outcome of this combination was the profoundly influential technical group known as BBN, whose pioneering integration of acoustics with building technology is echoed by many consulting groups throughout the world.

  17. 30 CFR 18.33 - Finish of surface joints.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Finish of surface joints. 18.33 Section 18.33... Requirements § 18.33 Finish of surface joints. Flat surfaces between bolt holes that form any part of a flame... § 18.31(a)(6). All metal surfaces forming a flame-arresting path shall be finished during...

  18. Locally reinforced timber joints with expanded tube fasteners

    NARCIS (Netherlands)

    Leijten, A.J.M.

    1999-01-01

    The study presented focuses on the development of a novel timber joint. Traditional timber joints with mechanical fasteners, particular dowel type fasteners, such as bolts exhibit a low strength and an unreliable stiffness and ductility caused by the presence of hole clearance and the unpredictable

  19. Study on full-length recoverable resin-metal bolts

    Institute of Scientific and Technical Information of China (English)

    孙玉宁; 康全玉

    2003-01-01

    The paper introduces a kind of full-length recoverable resin-metal bolts, expounds its structural principle and stress features, and gives some instances in laboratory tests and underground tests. The results show that full-length recoverable resin-metal bolts can be used for supporting the walls of class Ⅰ~Ⅲ mining gateways, that the anchoring force is 50 kN or so, and that the recoverability rate is more than 80%, thus the supporting effect is better than that of split-set bolts.

  20. STUDY ON GATEWAY BOLTING EXCAVATED IN INCLINED COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    陶连金; 王泳嘉; 张倬元

    1997-01-01

    A typical gateway is analyzed using fully-deformable discrete element method. The fractured zone around the gateway is measured in field. Based on the measurement results and theoretical analysis, a comprehensive support scheme adopting bolt and steel belt is proposed. Discrete element method is used to assess the bolting scheme, and displacement monitoring in field is also carried out. Having been put into practice, it is proved that the scheme is both successful and rational. According to theoretical analysis and monitoring in field, some importan tkeynotes that should be noticed in gateway bolting practice are presented as well.

  1. What Makes Usain Bolt Unique as a Sprinter?

    Science.gov (United States)

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-09-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and 200-m individual sprints and in the 4 × 100-m sprint relay. In addition, Bolt left us all wondering what record time he might have run had he not eased into the finish line in the 100-m dash. Naturally, one question many fans and observers immediately ask is: What makes Usain Bolt unique as a sprinter?

  2. An overview of bolt failures in nuclear systems

    International Nuclear Information System (INIS)

    The S.M. Stoller Corporation (SMSC) conducted a survey a material failures in nuclear plant systems using two data bases, i.e., Operating Plant Experience Code and Nuclear Power Experience. Information from the data bases was used to classify material failures as a function of time, type of plant, and type of component. Bolting failures represented 2 percent of all pressurized water reactor (PWR) material failures and 1 percent of all boiling water reactor (BWR) material failures. The majority of the PWR bolt failures have been due to stress corrosion of Inconel X-750 control rod guide tube support pins in Westinghouse reactors and A-286 reactor core thermal shield and core barrel support bolts in B ampersand W reactors. An improved mechanical design and aging treatment are expected to improve the stress corrosion resistance of Inconel X-750 pins. The replacement A-286 bolts employ peening in the head to shank area, rounded thread radii, machining versus hot forging of the head, a locking device to prevent loose parts, and reduced stresses as product improvements. A portion of reactor external PWR bolt failures were due to inadvertent boric acid corrosion of carbon, low alloy, and martensitic steels. Other causes of outside reactor PWR bolting failures were excessive stress, chloride-induced stress corrosion, oxidation, and fatigue of various materials in a variety of applications. BWR bolt failures have been relatively few and apparently not generic. Stress corrosion failures of Inconel X-750 fuel channel fasteners are reported judged to be caused by excess stress, nonoptimal heat treatment, and nonoptimal material selection. No failures have been reported in BWR alloy X-750 channel fastener bolts loaded to approximately 50-percent yield. 3 figs., 6 tabs

  3. What Makes Usain Bolt Unique as a Sprinter?

    Science.gov (United States)

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-01-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and…

  4. Bolt study - behaviour of bolts in drop accident scenarios of the Nirex 3m{sup 3} Box ILW package

    Energy Technology Data Exchange (ETDEWEB)

    Turner, G. [United Kingdom Nirex Ltd., Harwell (United Kingdom); Tso, C.F. [Arup, London (United Kingdom)

    2004-07-01

    The mission of Nirex is to provide the UK with safe, environmentally sound and publicly acceptable options for the long-term management of radioactive materials. One of the key tasks is to ensure that waste is packaged by waste producers in a form which is suitable for safe storage, transport, handling and potential disposal. In pursuit of this key requirement, Nirex has developed specifications to set the standard for the design and performance of waste packages, and has developed standard containers for the packaging of intermediate level (ILW) and some low level waste (LLW) - one of these is the 3m{sup 3} Box for immobilised operational and decommissioning ILW. The dimension envelope of this package is 1716 mm x 1716 mm in plan with 430 mm corner radii, 1226 mm tall. The maximum loaded weight is 12 tonnes. A generic design of this container has been developed, which is a welded structure manufactured from austenitic stainless steel (EN 10088-2 steel number 1.4404). The lid is connected to the body by 28 stainless steel bolts. An extensive study was carried out to develop a robust FE model of the bolts. The specific focus of this work was to use improved bolt modelling to optimize the design of the 3m{sup 3} Box, although this work could be applied to other bolted containers. This paper presents a summary of the findings from the study as follows: 1. Development of a FE bolt model for application in a 3m{sup 3} Box model. 2. Development and execution of a bolt testing programme which included tensile and shear tests on a total of 88 bolts, representing four grades of stainless steel materials, three thread sizes, and two geometries at three strain rates. 3. Benchmarking of the FE bolt model that can be used with confidence in simulating waste package behaviour in drop scenarios.

  5. THE EXPERIMENTAL CHECK OF RELIABILITY OF MATHEMATICAL MODELS OF FRICTION JOINTS

    Directory of Open Access Journals (Sweden)

    A. Yu. Klyukin

    2011-07-01

    Full Text Available Problem statement. Up to now, there has been no model describing work of friction joints on high-strength bolts in elastic stage. All previous models describe the structure after macrodis-placement when bolt was subjected to shearing and crushing. There also has been no model of complex joint with gusset and linings.Results and conclusions. The bolted joint model involving substitution of the friction rigidity for elastic links is presented. Stresses in complex joints of metal bridge are determined experimentally. The results obtained with the use of the model are compared with experimental results. Stresses at the points of joint beyond the reach of experiment are calculated. Experimental results supported the validity of the model.

  6. Non-dissipative joints in seismic resistant building frames - Bolted beam-to-column joints

    OpenAIRE

    Coméliau, Ludivine; Demonceau, Jean-François; Jaspart, Jean-Pierre

    2011-01-01

    According to Eurocode 8, earthquake resistant steel building frames shall be designed following either the “low dissipative structural behaviour concept” or the “dissipative structural behaviour concept”. In the second concept, the capability of parts of the structure to resist earthquake actions through inelastic behaviour is taken into account: energy is dissipated in plastic mechanisms. In such a design, it has to be ensured that the dissipative zones form where they are intended to and th...

  7. Application of ultrasonic phased array technique for inspection of stud bolts in nuclear reactor vessel

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Cracks initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It take too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signal reflected from every thread. In this study, the advanced ultrasonic phased array technique was introduced for inspect stud bolts. The phased array technique provide fast inspection and high detectability of defects. There are sector scanning and linear scanning method in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated.

  8. Development of plastic media blasting device for stud bolt

    International Nuclear Information System (INIS)

    Plastic media blasting is a mechanical cleaning method for removing paint, rust and/or anti-galling material etc on the surface of metal without damaging the metal surface. The method is suitable for cleaning the surface of reusable elements and parts such as bolts and nuts. Anti-galling material such as molybdenum disulfide is applied to fastening stud bolts used for the steam turbine rotor casing. It is necessary to remove this material when new anti-galling material is to be applied. Genden Engineering Services and Construction Co., and Morikawa Industries Corp., have developed a plastic media blasting device to clean the surface of stud bolt screw threads installed in the facility such as lower casing of the turbine. This paper reports the outline of the results. (author)

  9. TENSILE STRESS RELAXATION OF TURBINE BOLT STEELS AT HIGH TEMPERATURE

    Institute of Scientific and Technical Information of China (English)

    G.Q. Jia; H.W. Shen; Y.M. Zhu

    2004-01-01

    Stress relaxation behavior of two turbine bolt steels was evaluated by the manualcontrolled tensile stress relaxation test (TSRT) at high temperature. First, feasibility and the procedure of the manual-controlled tensile stress relaxation test (TSRT) is discussed and carried out on a general creep testing machine. And then, the experimental results from such type of test were compared to the existing data provided by certain Laboratory U.K. Overall good agreement between the results of manualcontrolled TSRT method and the existing data provides confidence in the use of the proposed method in practice. Finally, the experimental results of turbine bolt steels from TSRT were compared with that of bending test. It is observed that great difference exists between the results from two different type stress relaxation tests. It is therefore suggested that the results from TSRT method be adopted in turbine bolt design in engineering.

  10. On prestress stiffness analysis of bolt-plate contact assemblies

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Pedersen, Pauli

    2008-01-01

    Bolt connections are among the most important connections used in structures. The stiffnesses of the bolt and of the connected members are the primary qualities that control the lifetime of the connection. The stiffness of the bolt can be estimated rather easily, in contrast to the member stiffness......, but with finite element (FE) and contact analysis, it is possible to find the stiffness of the member. In the case of many connections and for practical applications, it is not suitable to make a full FE analysis. The purpose of the present paper is to find simplified expressions for the stiffness of the member......, including the case when the width of the member is limited. The calculation of the stiffness is based on the FE, including the solution to the contact problem, and we express the stiffness as a function of the elastic energy in the structure, whereby the definition of the displacements related...

  11. Analysis Of Comparative Strength Model Connection Bolts And Weld To The Plate Materials ST. 42

    OpenAIRE

    Saripuddin. M; Hammada Abbas

    2015-01-01

    The research objective to be achieved is determine the ratio of tensile strength connections of weld combination (longitudinal and transversal) with a tensile strength of connection models with 2 bolts, 3 bolts and 4 bolts. The method used is to form specimens of weld connections (longitudinal and transverse) and the model of connections (2, 3 and 4) bolts, and testing of tensile strength using a tensile test machine to produce maximum load value, the maximum tension and strain. T...

  12. Stress Evolution in Roadway Rock Bolts During Mining in a Fully Mechanized Longwall Face, and an Evaluation of Rock Bolt Support Design

    Science.gov (United States)

    Zhang, Kai; Zhang, Guimin; Hou, Rongbin; Wu, Yu; Zhou, Hongqi

    2015-01-01

    Rock bolts are widely used in coal mines throughout China. Approximately 8,000 km of roadways are excavated in coal mines every year in China, 80 % of which are supported by rock bolts. At present, the design of rock bolt support schemes is mainly based on analogies and experience from previous projects. In the present study, in order to evaluate the design of rock bolt support in roadways, several cross sections of a roadway were monitored for rock bolt stress during the roadway excavation and mining. The study results show that the stress in the rock bolts varied in the areas 20 m behind the excavating face and 30 m ahead of the mining face. For the rock bolts observed in this study, the max axial force was within the design limit of the bolts, thus the support design was shown to be acceptable. Then, numerical simulation was performed using FLAC3D to investigate the stress evolution in the rock bolts during the mining of the fully mechanized longwall face. The simulation results show an overall agreement with the in situ measurements. Finally, parametric study pertaining to length, anchorage length, and rock bolt spacing was carried out with the numerical model, and several suggestions for the support design were proposed.

  13. NUMERICAL SIMULATION ANALYSES ON REINFORCEMENT FUNCTION OF THE TENSIONED AND GROUTED BOLTS

    Institute of Scientific and Technical Information of China (English)

    邹喜正; 李华祥

    1998-01-01

    The purpose of the paper is to calculate the equivalent mechanics parameters of reinforced surroundings, which is based on the assume that the reinforcement of bolts is equivalent to the improvement of mechanics parameters of surroundings and combines with site engineering practice. Use numerical simulation analysis to study the reinforcement mechanism of full length bolts, thus to provide theoretical bases for bolting design.

  14. Analysis on the anchor mechanism of the full length resin bolt

    Institute of Scientific and Technical Information of China (English)

    宋彦波; 刘洪涛

    2003-01-01

    The purpose of this paper is to reveal the stress distribution characteristic along the full length anchor bolt. Based on the mechanic model set up, the author calculated the anchor mechanism of the full length resin rock-bolt. The stress distribution characteristic is different according to different type of surrounding-rock. The conclusion is important to optimize the roadway bolt support design.

  15. Characterization of an Unusual Cytoplasmic Chimera Detected in Bolting Garlic (Allium sativum L.) Clones

    Science.gov (United States)

    Production of a visible flower stalk or bolting has been used as a major trait to categorize garlic clones. Analysis of mitochondrial genome variation with PCR revealed differences between bolting and non-bolting clones of garlic. Screening 333 garlic accessions from diverse geographic origins rev...

  16. STRESS-STRAIN FINITE ELEMENT ANALYSIS AND FATIGUE LIFE PREDICTION FOR BOLTED CONNECTIONS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A cyclic plasticity model is used into finite element (FE) method to obtain the details of elastic-plastic stress-strain in the bolts under cyclic axial loading. Two criteria in multiaxial fatigue are employed to predict fatigue lives of bolts. The predicted fatigue lives are in favorable agreement with the experimental results for machined bolts.

  17. Controllable theory and applications for the wall bolting reinforcement in the roadway of seam

    Institute of Scientific and Technical Information of China (English)

    TAN Yun-liang; ZHANG Li-jun; XIAO Ya-xun

    2007-01-01

    By using the Radar penetrating technology and numerical simulations, the fractured zone could be easily determined. Both wall fractured zone and mining action of coal seam roadway were considered, and the bolt reinforcing criteria for wall including low limit condition and up limit condition were put up, which supply a basis for the bolt reinforcement design. For a particular engineering, there existed a bolt reinforcing controllable range which can be determined by the method put up in this paper. For the out of controllable range of bolt reinforcement in engineering, it is necessary to seek for other kind reinforcing technology, because the bolt reinforcing technology is not omnipotent.

  18. Evaluation of Roof Bolting Requirements Based on In-Mine Roof Bolter Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Syd S. Peng

    2005-10-01

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on this information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. For the prediction of roof geology and stability condition in real time, a micro processor was used and a program developed to monitor and record the drilling parameters of roof bolter. These parameters include feed pressure, feed flow (penetration rate), rotation pressure, rotation rate, vacuum pressure, oil temperature of hydraulic circuit, and signals for controlling machine. From the results of a series of laboratory and underground tests so far, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. The method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter was developed. Also, a set of computational rules has been developed for in-mine roof using measured roof drilling parameters and implemented in MRGIS (Mine Roof Geology Information System), a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. For the development of roof bolting criteria, finite element models were developed for tensioned and fully grouted bolting

  19. The strength of Glued-in Bolts after 9 Years In Situ Loading

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Damkilde, Lars;

    1996-01-01

    An experimental determination of the remaining strength of glued-in bolts after 9 years is presented. The hollow tapered bolts served as the blade to rotor hub connection of a windmill with wooden blades. The test method is presented along with the load history of the bolts, the recorded residual...... strength, the observed fracture modes and the force displacements curves. A total of 11 bolts were pulled out between undamaged bolts. The mean strength was found to be 362 kN with a standard deviation of 37 kN. This residual strength is 95% of previously recorded data. At fracture, a displacement between...

  20. To model bolted parts for tolerance analysis using variational model

    Directory of Open Access Journals (Sweden)

    Wilma Polini

    2015-01-01

    Full Text Available Mechanical products are usually made by assembling many parts. Among the different type of links, bolts are widely used to join the components of an assembly. In a bolting a clearance exists among the bolt and the holes of the parts to join. This clearance has to be modeled in order to define the possible movements agreed to the joined parts. The model of the clearance takes part to the global model that builds the stack-up functions by accumulating the tolerances applied to the assembly components. Then, the stack-up functions are solved to evaluate the influence of the tolerances assigned to the assembly components on the functional requirements of the assembly product. The aim of this work is to model the joining between two parts by a planar contact surface and two bolts inside the model that builds and solves the stack-up functions of the tolerance analysis. It adopts the variational solid model. The proposed model uses the simplified hypothesis that each surface maintains its nominal shape, i.e. the effects of the form errors are neglected. The proposed model has been applied to a case study where the holes have dimensional and positional tolerances in order to demonstrate its effectiveness.

  1. Mechanical Behavior of Dowel-Type Joints Made of Wood Scrimber Composite

    Directory of Open Access Journals (Sweden)

    Minjuan He

    2016-07-01

    Full Text Available As a renewable building material with low embodied energy characteristics, wood has gained more and more attention in the green and sustainable building industry. In terms of material resource and physical properties, scrimber composite not only makes full use of fast-growing wood species, but also has better mechanical performance and less inherent variability than natural wood material. In this study, the mechanical behavior of bolted beam-to-column joints built with a kind of scrimber composite was investigated both experimentally and numerically. Two groups of specimens were tested under monotonic and low frequency cyclic loading protocols. The experimental results showed that the bolted joints built with scrimber composite performed well in initial stiffness, ductility, and energy dissipation. A three-dimensional (3D non-linear finite element model (FEM for the bolted beam-to-column joints was then developed and validated by experimental results. The validated model was further used to investigate the failure mechanism of the bolted joints through stress analysis. This study can contribute to the application of the proposed scrimber composite in structural engineering, and the developed FEM can serve as a useful tool to evaluate the mechanical behavior of such bolted beam-to-column joints with different configurations in future research.

  2. Surface structured bonded composite-metal joint

    OpenAIRE

    Di Giandomenico, Vincenzo

    2014-01-01

    The design of structural joints is one of the critical challenges for the development of composite lightweight aircraft and motorsport structures. Despite the universal reliance upon mechanical fastening and adhesive bonding, the disadvantages of both when applied to high stiffness composites are considerable. For bolting and riveting these include added weight as laminates are thickened to account for stress concentrations. For bonding these include chemical uncertainties o...

  3. COMPOSITE MATERIAL BOLT THREADED NUT CONTACT FINITE ELEMENT ANALYSIS%复合材料锚杆螺纹螺帽接触有限元分析

    Institute of Scientific and Technical Information of China (English)

    温敏; 崔小朝; 王红霞

    2008-01-01

    利用ANSYS大型分析软件,建立属于表面非线性和材料非线性相耦合问题的复合材料锚杆螺纹螺帽联接的弹塑性轴对称接触有限元模型.对复合材料锚杆螺纹螺帽在间隙配合时轴向载荷作用下的应力应变场进行了数值计算.计算结果表明,复合材料锚杆螺纹螺帽联接能够满足煤矿安全生产的强度和刚度要求,为复合材料螺纹螺帽联接的设计提供了理论依据,对复合材料锚杆螺纹螺帽联接在工程实际中的推广使用有着重要的意义.%By means of large-scale analysis software ANSYS, a finite element model of elastic plastic axial symmetry contact problem is established which remained with the nonlinear surface and the nonlinear materials for the connecting of composite material bolt threaded nut. Stress-strain field has been calculated under the axial load with gap coordination of the composite material bolt threaded nut. The results indicate that, the joint of the composite material bolt threaded nut can satisfy the intensity and the rigidity request for the coal mine safety production. The researches in the paper have provided theoretical basis for the design of connecting the composite material bolt thread nut, and have important significance for widely using of the composite material bolt thread nut in project.

  4. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring.

    Science.gov (United States)

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag's antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt's information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  5. Ultrasonic Phased Array Techniques for Detection of Flaws of Stud Bolts in Nuclear Power Plants

    International Nuclear Information System (INIS)

    The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared

  6. Experimental Study on Methane Explosion Ignited by Sparks of Cable Bolt Breakage

    Institute of Scientific and Technical Information of China (English)

    MA Wen-ding; XU Jia-lin; ZHANG Shao-hua

    2004-01-01

    An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.

  7. Introducing aggregate into grouting material and its influence on load transfer of the rock bolting system

    Institute of Scientific and Technical Information of China (English)

    Cao Chen; Ren Ting; Chris Cook

    2014-01-01

    A fully grouted bolt provides greater shear load capacity for transmitting the load from the rock to the bolt, and vice versa. When grout fills irregularities between the bolt and the rock, a keying effect is cre-ated to transfer the load to the bolt via shear resistance at the interface and within the grout. Previous research has revealed that the mechanical properties of the grout had a great impact on the load transfer capacity of the rock bolting system. This paper presents a method to enhance the rock bolting strength by introducing metal granules into the grouting material. Experimental results suggest that both the average peak load of pullout tests and the total energy absorption of the system will increase if some metal gran-ules are mixed into the resin.

  8. Determination of rational support parameters of bolting and shotcreting with wire mesh in soft roadway

    Institute of Scientific and Technical Information of China (English)

    LIU She-yu; MA Nian-jie; LIU Shao-wei

    2005-01-01

    Based on a great number of measured data, the author put forward zonal compressive and tensile deformation mechanism of soft rock around roadway. By using self-supporting capacity of compressive zone and controlling rock deformation of tensile zone, the long bolt or short bolt group supporting form was given for different size of rock compressive zone and tensile zone. Finally, studied on the determining method of rational support parameters of bolting and shotcreting with wire mesh in different support technology.

  9. Improved wire stiffness with modified connection bolts in Ilizarov external frames: a biomechanical study.

    Science.gov (United States)

    Gessmann, Jan; Jettkant, Birger; Königshausen, Matthias; Schildhauer, Thomas Armin; Seybold, Dominik

    2012-01-01

    Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts featuring a smooth, unruffled wire-bolt interface. Six different ring and bolt configurations were tested using a simplified model consisting of a single ring and wire. The holding capacity at two different tightening torques (10 and 14 Nm) of classic cannulated bolts (CB) and slotted bolts (SB) was determined on Ilizarov and Taylor Spatial Frame (TSF™) rings, whereas the modified TrueLok™ CBs and SBs were used with the TrueLok™ rings. The wire stiffness was calculated via a regression analysis of the load-displacement graphs. The modified TrueLok™ bolts demonstrated significantly better slippage resistance than the classic bolts in all configurations and wire stiffness was significantly higher in the TrueLok™ frame set-ups. After maximum loading, all of the wires showed plastic deformation, including constant wire deflection and dent marks at the clamped wire ends. In conclusion, the decrease in wire stiffness can be explained mainly as a result of wire slippage, but plastic deformation and material yielding also contribute. The relatively simple modification made by roughening the wire-bolt interface results in improved holding capacity and wire stiffness. A frame that contains these modified TrueLok™ bolts should provide improved mechanical stiffness.

  10. Influence of Thread Root Radius on Maximum Local Stresses at Large Diameter Bolts under Axial Loading

    Directory of Open Access Journals (Sweden)

    Cojocaru Vasile

    2014-06-01

    Full Text Available In the thread root area of the threaded bolts submitted to axial loading occur local stresses, higher that nominal stresses calculated for the bolts. These local stresses can generate failure and can reduce the fatigue life of the parts. The paper is focused on the study of the influence of the thread root radius on the maximum local stresses. A large diameter trapezoidal bolt was subjected to a static analysis (axial loading using finite element simulation.

  11. Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Keith J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sokolov, Mikhail A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-04-30

    In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniques to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x1021 n/cm2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of

  12. Effects of Rock Bolting on Stress Distribution around Tunnel Using the Elastoplastic Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To ensure the stability of a tunnel during construction, rock bolts are usually installed, which affects the stress distribution around the tunnel.Therefore, it is necessary to study the effects of rock bolting on the stress distribution around the tunnel.In this article, the effects of rock bolting on the stress distribution around the tunnel, including the position and orientation of bolts, the overburden depths, and the bolt lengths, are simulated using the ANSYS software with an elastoplastic model.The effect of multiple bolts of 2 m and 1 m lengths on the stress distribution in the roof and on the lateral sides of a tunnel and at different overburden depths is considered.An important finding is that the tensile stress region that is very dangerous for rock in the bottom of the tunnel grows rapidly with increasing overburden depths when rock bolts are installed only in the roof or on the lateral sides of a tunnel.The determination of the length of the rock bolt used around a tunnel is dependent on the loads and the integrity of the rock mass around the tunnel.In addition, rock bolting around the tunnel can obviously reduce the coefficients and the size of the region of stress concentration, especially when installed in high-stress areas.This fact is very important and essential for the design of tunnels and ensures engineering safety in tunnel engineering.

  13. A critical flaw size approach for predicting the strength of bolted glass connections

    DEFF Research Database (Denmark)

    Watson, James; Nielsen, Jens Henrik; Overend, Mauro

    2013-01-01

    : the complex stress state, the inherent strength of glass and the magnitude of residual thermal stresses. This paper proposes a critical flaw size approach for bolted connections. The approach uses a numerical tempering model and nonlinear finite element analysis to determine the sizes of the critical flaws...... around the bolt hole, from destructive tests on bolted glass components subjected to in-plane loading. The critical flaw sizes determined by this approach agree with the flaw sizes obtained from optical microscopy. These flaw sizes are subsequently used to plot lifetime prediction curves for the bolted...

  14. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

    Science.gov (United States)

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  15. THE PRESENT SITUATION AND DEVELOPMENT OF THE BOLTING AND SHOTCRETING TECHNIQUE IN ROCK TUNNELING

    Institute of Scientific and Technical Information of China (English)

    DUANZhenxi

    1995-01-01

    Application of bolting and shotcreting used in Chinese coal mine underground engineering has been more than 40 years. By the end of 1993. total roadway length adopted bolting and shotcreting was over 21000km. Now, This paper describes developing and achievement of bolting and shotcreting briefly in the recent years. Meanwhile the paper puts forward solving and improving method for problems which exists in present design and construction. Final, combined with feature of coal mine, the paper puts forward some proposals about developing of bolting and shotcreting,dynamic management of both designs and construction, engineering measure and stability judgement as well.

  16. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2016-01-01

    Full Text Available In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system provided valuable information regarding the strengths and weaknesses of the proposed system.

  17. Theoretical and experimental research on characteristics of lateral vibration for a pre-stress bolt supporting system

    Institute of Scientific and Technical Information of China (English)

    LI Qing-feng; ZHU Chuan-qu; DUAN Yu

    2009-01-01

    According to the structure and stress trait of bearing bolts,a lateral-vibration mechanics model was established for them,and the relation between lateral-vibration fre-quency and axial load was analyzed; then,lateral-vibration trait of bearing bolts was stud-ied through laboratory simulation test.The results indicate that vibration frequency of bolt support system increases as well as axial force,the detection on axial load of bolts can be made by generating lateral vibration of bearing bolts.Theoretical and experimental re-search results show that frequency method is effective for detecting the axial force of bolt support system.

  18. Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress

    Institute of Scientific and Technical Information of China (English)

    李术才; 王洪涛; 王琦; 江贝; 王富奇; 郭念波; 刘文江; 任尧喜

    2016-01-01

    In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

  19. Lightning Bolt: an ecology of imagens, noises and extremes sounds

    Directory of Open Access Journals (Sweden)

    Fabrício Lopes da Silveira

    2011-12-01

    Full Text Available The article is focused exclusively on the music video “Dracula Mountain”, by north American noise-rock band Lightning Bolt. The aim is, in fact, sufficiently restricted: to describe the video and call it in question, considering it as a counterpoint to the band sonority and musical performance. At the end, we state that the video is both a symptom and a product of a very particular and contemporary media ecology, in which musical and audiovisual products and genres, as well as musical and audiovisual consumption habits are rebuilt and (repotentialized, sometimes inverted.

  20. Improvement activities for the maintenance of Baffle Former Bolts

    International Nuclear Information System (INIS)

    Baffle Former Bolts (BFBs) in PWR nuclear plant have the possibility to be cracked due to Irradiation Assisted Stress Corrosion Cracking (IASCC). The maintenance guideline for BFBs had been established from Thermal and Nuclear Power Engineering Society in 2000, and BFBs have been maintained in accordance with this maintenance rules. Recently, the new edition of this guideline has been published in order to reflect latest IASCC data and more precise stress evaluation of BFB into maintenance rules. The summary of the revised contents and these improvement activities are introduced in this paper. (author)

  1. Effects of curing time and frequency on ultrasonic wave velocity in grouted rock bolts

    Science.gov (United States)

    Madenga, V.; Zou, D. H.; Zhang, C.

    2006-05-01

    Grouted rock bolts are widely used to reinforce excavated ground in mining and civil engineering structures. To date, opportunities for testing the quality of the grout in grouted rock bolts have been limited to the pull-out tests and the over-coring methods. Both these methods are destructive, time-consuming and costly. These deficiencies have fueled research into the use of ultrasonic methods for testing the quality of the grout in rock bolts. However, only partial success has been achieved in these efforts chiefly due to inadequate knowledge of the ultrasonic wave characteristics such as wave velocity in grouted rock bolts. This paper presents results of an experimental study into the effects of curing time and testing frequency on the velocity of ultrasonic waves propagating along rock bolts grouted in concrete. A substantial wave velocity decrease, as much as 47.7% at certain frequencies, was recorded in rock bolts grouted in fully cured concrete in comparison to non-grouted bolts. The results demonstrate the importance of optimizing the selection of test frequencies as well as suggesting the possibility of a new approach based on wave velocity decrease for testing the grout quality of rock bolts.

  2. The Nuts and Bolts of Michaelis-Menten Enzyme Kinetics: Suggestions and Clarifications

    Science.gov (United States)

    Silverstein, Todd

    2011-01-01

    Matthew Junker's recent article describes a useful and effective enzyme kinetics application and analogy in which students simulate enzyme activity by unscrewing nut-bolt "substrate molecules", thus, converting them into separate nuts and bolts "products". A number of suggestions and corrections are presented that improve the clarity and accuracy…

  3. Enhancement of crack detection in stud bolts of nuclear reactor by ultrasonic technique

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safety of reactor vessels in nuclear power plants. Crack initiation and propagation were reported in stud bolts using closure of reactor vessel and head. Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure and radioactive leakage from nuclear reactor. In conventional ultrasonic testing for inspection of stud bolts, crack was detected by using shadow effect. It takes too much time to inspect stud bolt by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread. In this study, the signal processing technique for enhancing conventional ultrasonic technique and the advanced ultrasonic phased array technique were introduced for inspect stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. The phased array technique provides fast inspection and can be applied for structure of complex shape. There are sector scanning and linear scanning methods in phased array technique, and these scanning methods were applied to inspect stud bolt and detectability was investigated. (author)

  4. Device for distance welding of bolts with a remote controlled gun

    International Nuclear Information System (INIS)

    The welding gun includes two grounded contacts, on each side of the bolt to weld. They are mounted on springs for a better electric contact with the surface to be welded to the bolts. Remote control of the welding unit is provided for working where there is a radiation risk

  5. THE MECHANICAL MODEL OF THE FOREPOLING BOLT STRUCTURE FOR STUDYING THE PRE-SUPPORT MECHANISM

    Institute of Scientific and Technical Information of China (English)

    陶龙光; 侯公羽; 乔河

    1995-01-01

    Based on references ,the mechanical models have been developed to study the presupport mechanism of forepoling bolt structure in this paper. The following problems are discussed:(1) the pre-support mechanism of forepoling bolt structure and stress distribution on its upper broken rock! (2) loading state of forepoling bolt; (3) solution of arching in the cross section of excavation。

  6. Failure Analysis of Bolts%螺钉失效分析

    Institute of Scientific and Technical Information of China (English)

    吴伟

    2001-01-01

    对断裂螺钉的断口观察,分析了螺钉的装配情况,找出了断裂原因。%On the basis of observation of the ruptured section of a bolt, the author analyzes the assembled condition of the bolt. As a result, the rupture reason is found out.

  7. Laboratory evaluation of alloy X-750 clevis bolts removed from D.C. cook unit 1

    International Nuclear Information System (INIS)

    This paper summarizes the results of the laboratory evaluation performed by Babcock and Wilcox on Alloy X-750 clevis bolts removed from the Lower Radial Support System (LRSS) at D.C. Cook Unit 1. A total of 29 clevis bolts - 16 broken and 13 intact - were provided for laboratory analysis and testing to document the extent of degradation, evaluate the integrity of the intact bolts, and identify the bolt degradation/failure mechanism(s). The laboratory work scope included visual and stereo-visual examinations of all bolts. Based on the results of these examinations, four bolts - two broken and two intact - were selected for more detailed analysis/testing, including Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), optical metallography, microhardness, chemical analysis by Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), Rockwell hardness testing, and tensile testing. The laboratory data indicated the bolts failed by intergranular stress corrosion cracking (IGSCC). There was no evidence that the bolts failed due to fatigue cracking or mechanical overload. (authors)

  8. Practical Usage of Effect of Cold Weldability of Metals in Joint of Plastically Deformable Gasket and Flanges of Detachable Joint of Fuel Pipe-Line

    Science.gov (United States)

    Danchenko, V. G.

    2002-01-01

    The performed investigations of the character of changing the leakage of control gas through flange connections in the process of drawing- up the bolts in to calculation moment and subsequent lowering of bolt loading to zero have shown the following. Gradual reduction of leakage through a gasket occurs in the process of increasing the tightening torque up to its complete absence. But there is no leakage through the unloaded gasket after untwisting all nuts and removal of fastening bolts from flanges. The performed analysis has shown that this effect is caused by cold weldability of the gasket with flanges; this is a result of flowing of its material into microrough holes of contact surfaces of flanges at plastic deformation with formation of strong and dense contact. Some technological methods of formation of undetachable joint have been developed for practical application of this effect. According to one of those methods, drawing- up the gasket is performed with the help of flanges preliminarily. Those bolts are substituted by less strong standard bolts for drawing- up by less moment after achievement of stress needed. Method of pressurization of the joint is more effective when technological detachable flanges and bolts are used for reduction of the gasket up to its plastic state. Those flanges and bolts are removed after drawing- up; after that standard flanges are loaded by the moment used for reception of effort only from pressure of operational medium in the pipe- line (Qoper.m.) because drawing- up of the gasket by effort (Qeff.) that provides its plastic state, is already achieved. Then we exclude the first component (Qeff.) in dependence which is known from technical literature: Qdraw. = Qeff . + Qoper .m. = qFgas. + PFpip. (1), and the final formula for calculation of the effort of drawing- up the joint (in which drawing- up the gasket with provision of cold weldability is carried out preliminarily before drawing- up the standard bolts) is expressed in

  9. EVALUATION OF TROQUE VS CLOSURE BOLT PRELOAD FOR A TYPICAL CONTAINMENT VESSEL UNDER SERVICE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.

    2010-02-16

    Radioactive material package containment vessels typically employ bolted closures of various configurations. Closure bolts must retain the lid of a package and must maintain required seal loads, while subjected to internal pressure, impact loads and vibration. The need for insuring that the specified preload is achieved in closure bolts for radioactive materials packagings has been a continual subject of concern for both designers and regulatory reviewers. The extensive literature on threaded fasteners provides sound guidance on design and torque specification for closure bolts. The literature also shows the uncertainty associated with use of torque to establish preload is typically between 10 and 35%. These studies have been performed under controlled, laboratory conditions. The ability to insure required preload in normal service is, consequently, an important question. The study described here investigated the relationship between indicated torque and resulting bolt load for a typical radioactive materials package closure using methods available under normal service conditions.

  10. Development of signal processing technique for inspection of defects in stud bolts of nuclear reactor vessel

    International Nuclear Information System (INIS)

    Bolt failure is a hazard factor for the safety of reactor vessels in nuclear power plants. However, in the practical application of ultrasonic technique for crack detection in stud bolt, the classification of crack signal from the signals reflected from threads in stud bolt is very difficult. In this study, shadow effect technique combined with new signal processing method has been investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of new signal processing concept is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different from the reference signals. It has shown that the small flaws can be effectively detected by novel ultrasonic technique combined with this new signal processing concept.

  11. Detection of cracks in stud bolts of nuclear reactor by novel ultrasonic technique

    International Nuclear Information System (INIS)

    The stud bolt is one of the most critical parts for the safety of reactor vessels in nuclear power plants. However, in the practical application of ultrasonic technique for crack detection in stud bolt, the classification of crack signal from the signals reflected from threads in stud bolt is very difficult. In this study, shadow effect technique combined with new signal processing method has been investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of new signal processing concept is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different from the reference signals. It has shown that the small flaws can be effectively detected by novel ultrasonic technique combined with this new signal processing concept. (orig.)

  12. Enhancement of crack detection in stud bolts of nuclear reactor by ultrasonic signal processing technique

    International Nuclear Information System (INIS)

    'Full-text:' The stud bolts is one of the most critical parts for safety of reactor vessels in the nuclear power plants. However, in the application of ultrasonic technique for crack detection in stud bolt, some difficulties encountered are classification of crack signal from the signals reflected from threads part in stud bolt. In this study, shadow effect technique combined with new signal processing method is Investigated to enhance the detectability of small crack initiated from root of thread in stud bolt. The key idea of signal processing is based on the fact that the shape of waveforms from the threads is uniform since the shape of the threads in a bolt is same. If some cracks exist in the thread, the flaw signals are different to the reference signals. It is demonstrated that the small flaws are efficiently detected by novel ultrasonic technique combined with this new signal processing concept. (author)

  13. Vibration Characteristic of Anchoring System of Bolt and Elastic Wave Propagation Law

    Institute of Scientific and Technical Information of China (English)

    WANG Cheng; LI Yi; NING Jian-guo; LIN Hua-chang

    2006-01-01

    Based on one-dimension wave theory, the propagation law of elastic wave along the rock bolt, rock medium and their coupling system are researched, and the attenuation law and propagation mechanism of wave in the anchoring system are obtained. Meanwhile, the studies on end reflection and dynamic response under load are also carried out experimentally, the relationship between anchoring length and excited wave length is obtained when the end reflection of bolt emerges, and it is concluded that under the condition of bolt loaded,as the load increases, the reflection of the upper interface of anchoring segment weakens while the end reflection strengthens relatively, hence the energy attenuation increases. These results provide some important theory basis for measuring the effective anchoring length of bolt, judging the bonding quality of anchoring end and surrounding rock, and estimating the utmost load force of bolt.

  14. Fasteners 1 dimensional standards for bolts, screws and studs national standards

    CERN Document Server

    2011-01-01

    This 7th edition of DIN Handbook 10 contains 90 currently valid German national standards (DIN Standards) dealing with the dimensions of bolts, screws and studs. In this updated compilation four standards are new: DIN 787 T-head bolts; DIN 1445 Clevis pins with head and threaded portion; DIN 5903-1 Fish bolts - Part 1: With round head and oval neck; DIN 5903-2 Fish bolts - Part 2: With square head. 27 standards have been revised for this edition. DIN Handbook 10 is the companion volume to DIN Handbook 362 "Fasteners 6 - Dimensional standards for bolts and screws - European Standards", which reflects the state of the art in Europe. Together, DIN Handbooks 10 and 362 provide the user with a comprehensive overview of standards in the fasteners sector.

  15. Effects of sowing time on bolting and returning green in welsh onion

    Institute of Scientific and Technical Information of China (English)

    JI Jiaojiao; LIU Jing; XING Xiaoxue; JIANG Xinmei

    2007-01-01

    Qiyechangbai and Hadacongl were used to study the relationship of the leaf age of overwinter to bolting and returning green by the difference of sowing time. The results showed that the earlier the seeds were sown, the older leaf age of overwinter was, the higher the rates of returning green and bolting rate were, the earlier the bolting time was. The leaf age of overwinter of Qiyechangbai sown August 31 to September 14 was 2.1-3.1 leaves and the rate of returning green was 86.5%-92.1%, while the leaf age of overwinter of Hadacongl sown September 7 to September 14 was 2.3-2.7 leaves and the rate of returning green was 88.5%-93.8%, both varieties didn't bolt. In addition, in the same sowing time, the bolting rate of Hadacong1 was higher than that of Qiyechangbai slightly.

  16. Experimental and Numerical Investigation of an End Plate Connection with Using Long Shank SMA Bolts

    Institute of Scientific and Technical Information of China (English)

    Hongwei Ma; Yongbing Zhu; Michael CH Yam; Yang Wang

    2015-01-01

    Superelastic shape memory alloys ( SMAs ) have the ability to recover their original shape after experiencing large strains. End⁃plate connection with using superelastic long shank SMA bolts is proposed in this paper. By using strong beam⁃weak bolt cluster design methodology and special configurations to strength beam ends, a superelastic hinge is expected to form in column flange. To validate the mechanical behavior of the proposed beam⁃to⁃column connection, both quasi⁃static tests and numerical analysis are conducted with cyclic transverse loads applied on the beam ends. The results indicate the connection deformations concentrate on the long shank SMA bolts upon loading and the bolt cluster rotates around the axis near beam flange. By using the super elastic effect, the SMA bolts recover most elongations and the connection recovers to its original shape after experiencing 0�02 rad interstorey drift angle. The connection shows obvious self⁃centering properties.

  17. Thermo-mechanical finite element analyses of bolted cask lid structures

    Energy Technology Data Exchange (ETDEWEB)

    Wieser, G.; Qiao Linan; Eberle, A.; Voelzke, H. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2004-07-01

    The analysis of complex bolted cask lid structures under mechanical or thermal accident conditions is important for the evaluation of cask integrity and leak-tightness in package design assessment according to the Transport Regulations or in aircraft crash scenarios. In this context BAM is developing methods based on Finite Elements to calculate the effects of mechanical impacts onto the bolted lid structures as well as effects caused by severe fire scenarios. I n case of fire it might be not enough to perform only a thermal heat transfer analysis. The complex cask design in connection with a severe hypothetical time-temperature-curve representing an accident fire scenario will create a strong transient heating up of the cask body and its lid system. This causes relative displacements between the seals and its counterparts that can be analyzed by a so-called thermo-mechanical calculation. Although it is currently not possible to correlate leakage rates with results from deformation analyses directly an appropriate Finite Element model of the considered type of metallic lid seal has been developed. For the present it is possible to estimate the behaviour of the seal based on the calculated relative displacements at its seating and the behaviour of the lid bolts under the impact load or the temperature field respectively. Except of the lid bolts the geometry of the cask and the mechanical loading is axial-symmetric which simplifies the analysis considerably and a two-dimensional Finite Element model with substitute lid bolts may be used. The substitute bolts are modelled as one-dimensional truss or beam elements. An advanced two-dimensional bolt submodel represents the bolts with plane stress continuum elements. This paper discusses the influence of different bolt modelling on the relative displacements at the seating of the seals. Besides this, the influence of bolt modelling, thermal properties and detail in geometry of the two-dimensional Finite Element models on

  18. Remote controlled stud bolt handling device for reactor pressure vessel

    International Nuclear Information System (INIS)

    In nuclear power stations, at the time of regular inspection, the works of opening and fixing the upper covers of reactor pressure vessels are carried out for inspecting the inside of reactor pressure vessels and exchanging fuel rods. These upper covers are fastened with many stud bolts, therefore, the works of opening and fixing require a large amount of labor, and are done under the restricted condition of wearing protective clothings and masks. Babcock Hitachi K.K. has completed the development of a remotely controlled automatic bolt tightenig device for this purpose, therefore, its outline is reported. The conventional method of these works and the problems in it are described. The design of the new device aimed at the parallel execution of cleaning screw threads, loosening and tightening nuts, and taking off and putting on nuts and washers, thus contributing to the shortening of regular inspection period, the reduction of the radiation exposure of workers, and the decrease of the number of workers. The function, reliability and endurance of the new device were confirmed by the verifying test using a device made for trial. The device is composed of a stand, a rail and four stations each with a cleaning unit, a stud tensioner and a nut handling unit. (K.I.)

  19. Mechanical Model of Steel-concrete Composite Joint under Sagging Bending Moment

    Science.gov (United States)

    Pisarek, Zdzisław

    2012-06-01

    In buildings with steel-concrete composite floors, joints are designed to transmit mainly hogging bending moment. In case of the large horizontal loads due to wind, earthquake or accidental events, sagging bending moments in a joint can also occur. Additionally, large deformations of the structure cause tying and prying effects. In the paper, a mechanical model based on "component method" for evaluation of characteristics of the composite joint is presented. The influence of tying and prying actions on distribution of the internal forces in a joint is also analyzed. The procedure for calculation of the characteristics of the composite joint with bolted endplate connection is elaborated too.

  20. Numerical simulation of attenuation and group velocity of guided ultrasonic wave in grouted rock bolts

    Science.gov (United States)

    Cui, Y.; Zou, D. H.

    2006-08-01

    In this paper, the guided ultrasonic wave propagating in grouted rock bolts was simulated with finite element method. An 800 mm partially grouted cylindrical rock bolt model was created. Dynamic input signals with frequency from 25 to 100 kHz were used to excite ultrasonic wave. The simulated waveform, group velocity and amplitude ratio matched well with the experimental results. This model made it possible to study the behaviour of the guided waves in the grouted bolt along its central axis. Analysis of the simulated results showed that the group velocity in grouted rock bolts is constant along the grouted length, and the boundary effect on the group velocity is negligible. This paper also presents methods to determine the attenuation coefficient from simulation and to determine the boundary effect on attenuation at the bolt ends. The analysis showed that the attenuation of the guided wave propagating inside the grouted bolts is similar to the theoretical solution in steel bar with infinite length. After correction for the boundary effects the grout length of a grouted rock bolt can be determined using the measured attenuation, with sufficient accuracy.

  1. 连杆螺栓的强度分析%Strength Analysis for Connecting Rod Bolt

    Institute of Scientific and Technical Information of China (English)

    李笑岩; 付冰洋; 张建云; 张士永

    2016-01-01

    对连杆螺栓受力进行了研究,利用ANSYS对螺栓进行静力学分析,得出螺栓的应力分布状况。对连杆螺栓断裂事故进行了分析,得出可能造成螺栓断裂的原因;利用Miner疲劳损伤理论和ANSYS软件,分别对连杆螺栓进行疲劳寿命计算,预估螺栓的使用寿命。%The force of the connecting rod bolts is researched in the paper. Using ANSYS software, static analysis of connecting rod bolts is calculated. And the stress distribution of connecting rod bolts is got from ANSYS. The accident that the connecting rod bolts broken is analyzed and the reason for the bolt fracture is obtained. Using Miner Fatigue Damage Theory and ANSYS software, the fa-tigue life of connecting rod bolt is calculated and the using life of bolt is estimated.

  2. A Study on the Fracture Control of Rock Bolts in High Ground Pressure Roadways of Deep Mines

    Directory of Open Access Journals (Sweden)

    Wen Jinglin

    2015-01-01

    Full Text Available According to the frequent fractures of rock bolts in high ground pressure roadways of deep mines, this paper analyzes the mechanism of fractures and concludes that high ground pressure and material de-fects are main reasons for the fracture of rock bolts. The basic idea of fracture control of rock bolts in high ground pressure roadways of deep mines is to increase the yield load and the limit load of rock bolt materials and reduce the actual load of rock bolts. There are four ways of controlling rock bolt fracture: increasing the rock bolt diameter, strengthening bolt materials, weakening support rigidity and the implementation of double supporting. With the roadway support of the 2302 working face of a coal mine as the project background, this paper carries out a study on the effect of two schemes, increasing the rock bolt diameter and the double supporting technique through methods of theoretical analysis, numerical simulation and so on. It determines the most reasonable diam-eter of rock bolts and the best delay distance of secondary support. Practices indicate that rock bolt fracture can be effectively controlled through the double supporting technique, which strengthens the roof and two sides through the first supporting technique and strengthens side angles through the secondary supporting technique.

  3. Development of Automatic Ultrasonic Testing Equipment for Pressure-Retaining Studs and Bolts in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Bolting degradation problems in primary coolant pressure boundary applications have become a major concern in the nuclear industry. In the bolts concerned, the failure mechanism was either corrosion wastage(loss of bolt diameter) or stress-corrosion cracking. Here the manual ultrasonic testing of RPV(Reactor Pressure Vessel) and RCP(Reactor Coolant Pump) stud has been performed. But it is difficult to detect indications because examiner can not exactly control the rotation angle and can not distinguish the indication from signals of bolt. In many cases, the critical sizes of damage depth are very small(1-2 mm order). At critical size, the crack tends to propagatecompletly through the bolt under stress, Resulting in total fracture. Automatic stud scanner for studs(bolts) was developed because the precise measurement of bolt diameter is required in this circumstance. By use of this scanner, the rotation angle of probe was exactly controlled and the exposure time of radiations was reduced

  4. Application of shape memory alloys in bolted flanged connections

    International Nuclear Information System (INIS)

    The Shape Memory Effect (SME) and super elasticity of the Shape Memory Alloys (SMA) can make up the clamping force decreasing caused by the creep and relaxation behavior in Bolted Flanged Connections (BFC), and improve the reliability of the BFC. Advances in the research of SMA in BFC home and abroad is summarized in this paper. The application prospects of Ti-Ni-Pd, Ti-Ni-Hf, Fe-Mn-Si, Cu-Al-Ni and Ni-Al-Mn in the BFC are also discussed. It is considered that the compressive characteristics of the parent phase of SMA should be studied further for the application of SMA to BFC besides the design of sealing structure. When more basic research data is accumulated, BFC with high sealing performance for the critical engineering applications can be developed based on the comprehensive consideration of the stability and reliability of the clamping force. (authors)

  5. Bolt-Grout Interactions in Elastoplastic Rock Mass Using Coupled FEM-FDM Techniques

    Directory of Open Access Journals (Sweden)

    Debasis Deb

    2010-01-01

    Full Text Available Numerical procedure based on finite element method (FEM and finite difference method (FDM for the analysis of bolt-grout interactions are introduced in this paper. The finite element procedure incorporates elasto-plastic concepts with Hoek and Brown yield criterion and has been applied for rock mass. Bolt-grout interactions are evaluated based on finite difference method and are embedded in the elasto-plastic procedures of FEM. The experimental validation of the proposed FEM-FDM procedures and numerical examples of a bolted tunnel are provided to demonstrate the efficacy of the proposed method for practical applications.

  6. Research on coal roadway truss and numerical simulation of bolting support effect

    Institute of Scientific and Technical Information of China (English)

    NING Jian-guo; ZHANG Xin-guo; GAO Ming-tao

    2007-01-01

    According to the research results in world, the paper comprehensively analyzed and gave a demonstration of mechanism of single-truss and its stressing advantage. Comparison and analysis effect were given to single-truss and bolting supporting. By the way of element simulation. The paper shows that single truss supporting have better effect to bolting supporting to improving the stress condition of surrounding rocks, controlling the surrounding rocks plastic failure development zone and deformation effect of surrounding rocks, which provided the elementary theory basis to the research, experiment and expanding the single-truss bolting technology in colliery.

  7. Stress state and caving danger of the roof in bolt supporting roadway

    Institute of Scientific and Technical Information of China (English)

    LIU Shao-wei; XU Li-li

    2006-01-01

    The start point of this text is the bottleneck problem of bolt supporting coal entry that is security problem of bolt supporting roof,we divide one entry into some sections with different stress, simulate stress field of wall rock and rockbolt solidified at different sections used umbrella disperse soft UDEC(universal distinct element code), we educe that the stress level of wallrock and bolt solidified is higher in roof fall risk section, and roof rockbolt load can reflect this rule clearly, that offer an important guideline in monitoring entry roof fall risk.

  8. Expression of NO scavenging hemoglobin is involved in the timing of bolting in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Hebelstrup, Kim Henrik; Jensen, Erik Østergaard

    2008-01-01

    -symbiotic hemoglobin gene, GLB2, in Arabidopsis thaliana. Lines with GLB1 silencing had a significant delay of bolting and after bolting, shoots reverted to the rosette vegetative phase by formation of aerial rosettes at lateral meristems. Lines with overexpression of GLB1 or GLB2 bolted earlier than wild type plants...... molecule, NO. So far, NO scavenging has only been demonstrated for class 1 non-symbiotic hemoglobins. A direct assay in Arabidopsis leaf cells shows that GLB1 as well as the class 2 non-symbiotic hemoglobin, GLB2, scavenge NO in vivo. NO has also been demonstrated to be a growth stimulating signal...

  9. Prying Force Calculation and Design Method for T-shaped Tensile Connector with High Strength Bolt

    Institute of Scientific and Technical Information of China (English)

    Zhaoxin Hou; Guohong Huang; Chao Gong

    2015-01-01

    In order to establish the design method for T⁃shaped tensile connector with high strength bolt, the theoretical analysis is carried out. Firstly, it analyzes the performance of the connector and establishes prying force calculation model. Based on the model, prying force equation and function between bolt prying force and flange thickness is derived, and the min and max thickness requirement of flange plate under a certain tension load is then obtained. Finally, two simplified design methods of the connector are proposed, which are bolt pulling capacity method and flange plate bending capacity method.

  10. Biomimetic Composite Structural T-joints

    Institute of Scientific and Technical Information of China (English)

    Vimal Kumar Thummalapalli; Steven L.Donaldson

    2012-01-01

    Biological structural fixed joints exhibit unique attributes,including highly optimized fiber paths which minimize stress concentrations.In addition,since the joints consist of continuous,uncut fiber architectures,the joints enable the organism to transport information and chemicals from one part of the body to the other.To the contrary,sections of man-made composite material structures are often joined using bolted or bonded joints,which involve low strength and high stress concentrations.These methods are also expensive to achieve.Additional functions such as fluid transport,electrical signal delivery,and thermal conductivity across the joints typically require parasitic tubes,wires,and attachment clips.By using the biomimetic methods,we seek to overcome the limitations which are present in the conventional methods. In the present work,biomimetic co-cured composite sandwich T-joints were constructed using unidirectional glass fiber,epoxy resin,and structural foam.The joints were fabricated using the wet lay-up vacuum bag resin infusion method.Foam sandwich T-joints with multiple continuous fiber architectures and sandwich foam thickness were prepared.The designs were tested in quasi-static bending using a mechanical load frame.The significantweight savings using the biomimetic approaches is discussed,as well as a comparison of failure modes versus architecture is described.

  11. Twofold hidden conformal symmetry of Kerr-Bolt black holes

    Institute of Scientific and Technical Information of China (English)

    M.R. Setare; V. Kamali

    2012-01-01

    Previously we have shown that a four-dimensional Kerr-Bolt black hole in non-extremal and also in extremal cases could be described by a holographic two-dimensional (2D) conformal field theory (CFT) [Ghezelbash A M,Kamali V and Setare M R 2010 Phys.Rev.D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074].Motivated by recent work [Chen C M,Huang Y M,Sun J R,Wu M F and Zou S J 2010 Phys.Rev.D 82 066004],we show that there is another holographic description for these black holes.The first description is called the J-picture,whose construction is based on the black hole angular momentum.The new description is called the Q-picture,whose constructions originate from the nut charge of the black hole.Similar to the previous cases [Ghezelbash A M,Kamali V and Setare M R 2010 Phys.Rev.D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074],we show that this new picture for a low frequency limit of the wave equation of a massless charged scalar field in the background of a Kerr-Bolt black hole can be written as the Casimir of SL(2,R) symmetry.Our result shows that the entropy of the black hole is reproduced by the Cardy formula.In addition,the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional CFT.

  12. Stress analysis method for clearance-fit joints with bearing-bypass loads

    Science.gov (United States)

    Naik, R. A.; Crews, J. H., Jr.

    1989-01-01

    Within a multi-fastener joint, fastener holes may be subjected to the combined effects of bearing loads and loads that bypass the hole to be reacted elsewhere in the joint. The analysis of a joint subjected to search combined bearing and bypass loads is complicated by the usual clearance between the hole and the fastener. A simple analysis method for such clearance-fit joints subjected to bearing-bypass loading has been developed in the present study. It uses an inverse formulation with a linear elastic finite-element analysis. Conditions along the bolt-hole contact arc are specified by displacement constraint equations. The present method is simple to apply and can be implemented with most general purpose finite-element programs since it does not use complicated iterative-incremental procedures. The method was used to study the effects of bearing-bypass loading on bolt-hole contact angles and local stresses. In this study, a rigid, frictionless bolt was used with a plate having the properties of a quasi-isotropic graphite/epoxy laminate. Results showed that the contact angle as well as the peak stresses around the hole and their locations were strongly influenced by the ratio of bearing and bypass loads. For single contact, tension and compression bearing-bypass loading had opposite effects on the contact angle. For some compressive bearing-bypass loads, the hole tended to close on the fastener leading to dual contact. It was shown that dual contact reduces the stress concentration at the fastener and would, therefore, increase joint strength in compression. The results illustrate the general importance of accounting for bolt-hole clearance and contact to accurately compute local bolt-hole stresses for combined bearings and bypass loading.

  13. Failure Modelling of Woven GFRP Bolted Joints under Quasi-Static Loading

    Directory of Open Access Journals (Sweden)

    Mohd Hilton Ahmad

    2013-12-01

    Full Text Available Current work concentrates in modelling failure and damage of various woven fabric reinforcement system taken from selected literatures. Experimental observations under quasi-static loading revealed that initial failure occurs at notch vicinity consist of one or combinations of matrix cracking, splitting and laminate de-lamination. The crack then propagated along net-section of distance of about one notch radius size, which thereafter occurrence usually corresponds to catastrophic failures that seen significant tow fractures. The distance of cracked zone signifies ultimate material failure usually referred as “effective damage zone” that useful to be implemented within fracture mechanics concept. These complex morphologies mechanisms can be represented by implementing physically-based constitutive model. Series works of notched woven fabric composite systems plate were implemented within two-dimensional extended finite element method (XFEM framework were carried out by implementing constitutive models based on basic material properties data of respective system. Good agreement is shown in comparison with experimental data in various and other closed-form approaches composite fabric systems.

  14. Operational monitoring of temperature and state of stress of primary collectors, their stud bolts and cover and temperatures of steam generator's pressure vessel at the nuclear power unit WWER 440

    International Nuclear Information System (INIS)

    Both primary collectors of the WWER 440 steam generator (STGE) are vertically positioned inside the STGE pressure vessel and connected in their lower part to the primary piping and closed at their upper part by primary covers. The primary cover is pushed against the primary collector flange by 20 stud bolts. Two nickel packing rings are fitted between the primary cover and collector. A leakage in the collector-cover junction could cause flow of the radioactive water into the clean secondary water. If the junction is made in accordance with the Soviet standard design the computed stresses exceed the allowable value in the stud bolts by a factor of 1.5. Therefore an improved design of the primary collector - primary cover flange joint was designed and tested on one STGE at a WWER 440 nuclear power unit in Czechoslovakia. The paper describes the system of joint properties measurement, gives some substantial characteristics of the new stud bolts and primary cover design and comments on significant measured results of state of stress and temperatures in comparison with the operational regime of the STGE. (orig.)

  15. The research of the stud bolt bore checking equipment of the nuclear reactor pressure vessel

    International Nuclear Information System (INIS)

    This article introduces a kind of new equipment that can work under the environment of high radiation and can-automaticly check the main stud bolt bore. The technical parameters and key techniques of the checking equipment are presented. (authors)

  16. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    Institute of Scientific and Technical Information of China (English)

    Esterhuizen Gabriel S; Tulu Ihsan B

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the mod-ified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof.

  17. Performance evaluation of bolt-cutter system on first Taurus launch

    Science.gov (United States)

    Baban, F.; Williams, R.; Amimoto, S.; Hansen, W.; Bixler, T.

    1994-10-01

    In rapid response to the request of the Space Test and Experimentation Directorate in Space Launch Operations, a launch-critical experimental investigation was conducted to evaluate the performance of a particular bolt-cutter system for separating stages on the first Taurus launch. The tests were to examine the variation of tension preloading on the bolt system and to demonstrate the tolerable margin on this parameter for such launches with the new types of bolts since the preloading was known to vary as much as 12% from a preset value before launch. We planned and carried out the experiment, designed and assembled the fixture to properly simulate flight application, and developed diagnostics. Four bolt cutters were purchased from the manufacturer for these tests, and one was provided by the contractor. In addition to the obvious requirement to demonstrate the successful severing of bolts under varying preloads, ignition-wire current and timing of chisel impact on the bolt were monitored. An optical diagnostic was designed to determine the flyout velocity and kinetic energy of the broken pieces. These latter measurements will be useful in anchoring performance codes simulating and assessing the structural dynamics of the bolt-cutter function for future missions. The tests were conducted successfully and the bolts were severed successfully in all five tests. The preloads were successively lowered from 2,500 lb to 2,250, 2,000, 1,500, and 1,000 lb These tests contributed in a timely manner to the STEP launch decision and to launch mission assurance. They demonstrated important margin to the nominally set 3,200 lb. preload. The entire complicated experimental program from inception to completion was accomplished in less than three weeks.

  18. On the performance of Usain Bolt in the 100 metre sprint

    CERN Document Server

    Gómez, J J Hernández; Gómez, R W

    2013-01-01

    A theoretical model of the performance of the 100 m world record sprint of Usain Bolt during the 2009 World Championships at Berlin is developed, assuming a drag force proportional to $v$ and to $v^2$. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Amateur of Athletics Federations that recorded Bolt's position with a LAVEG (laser velocity guard) device. It is worth to note that our model works only for short sprints.

  19. Bolting sequence for attaching the container to the strong-back for 241SY101

    International Nuclear Information System (INIS)

    This bolting sequence is for attaching the container to the strong-back for Tank 241-SY-101. This supporting document includes information for the proper bolting sequence for attaching the container to the strong-back is found in supporting document WHC-SD-WM-DA-165 (WHC 1994a) and is in accordance with Standard Arch-Civil Design Criteria, Design Loads for Facilities (SDC 4.1) Safety Class 3

  20. A new approach for field instrumentation in grouted rock bolt monitoring using guided ultrasonic waves

    Science.gov (United States)

    Zou, D. H.; Cui, Y.

    2011-11-01

    A rock bolt installed in the field for ground support has only one short exposed end on the rock surface. This condition has posed challenges in field instrumentation. In this paper, a new approach for field monitoring of grouted rock bolts using guided ultrasonic waves is proposed with the receiving transducer on the grout surface near the exposed end of the bolt. The effects of the receiver location are studied with numerical modeling. A location correction factor is introduced to correlate the amplitude ratio along the bolt and that on the grout surface. Experiments are conducted to verify the modeling results. This research indicates that it is practically possible to receive meaningful signals with the receiver on the grout surface and that with the recorded data the attenuation and wave velocity of guided waves in grouted rock bolts can be determined with reasonable accuracy. The proper receiver location is found to be 27 to 32 mm from the bolt center for the test condition.

  1. FEM analyses of stress and deformation of a flexible inner pressure bolt

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhong-he; WANG Wei-qiang; ZHANG Le-wen

    2008-01-01

    The flexible inner pressure bolt is a new kind and new structural bolt (anchor rod). A number of structural improvements and performance test have been carried out. The bolt has superior compatibility to the soft crag and the large distortion tunnel with its flexibility. In order to study its stress, deformation and interaction mechanism thoroughly, a number of large distortion calculations and analyses have been carried out on the bolt by FEM (finite element method), especially with the ANSYS software, based on the updated Lagrangian law. The results show that the maximum stress of the inner wall of the bolt is consistent with an elastic analytic solution. The maximum stress on the body occurs in the vicinity of the enhancement material. The link enhancement of the body seems to be quite essential. The experimental results indicate that the maximum injection pressure in the bolt is 2.5 MPa without link enhancement and 8.3 MPa with the enhancement. This link enhancement effect is highly significant. These results provide some basis for the design, application and anchoring stress analysis of the holt.

  2. Ultimate strength of single shear bolted connections with cold-formed ferritic stainless steel

    Institute of Scientific and Technical Information of China (English)

    Jin-seong LIM; Tae-soo KIM; Seung-hun KIM

    2013-01-01

    This paper is focused on the structural behavior of the single shear bolted connections with thin-walled ferritic stainless steel.The purpose of this study is to investigate the ultimate behaviors,such as ultimate strength and fracture mode of the single shear bolted connections of thin-walled ferritic stainless steel (low cost steel) rather than austenitic stainless steel (high cost steel).Bolt arrangement and end distance parallel to the direction of applied load are considered as main variables of the test specimens for bolted connections.Specimens have a constant dimension of edge distance perpendicular to the loading direction,bolt diameter,pitch,and gauge.A monotonic tensile test for specimens has been carried out and some bolted connections with long end distance showed curling (out of plane deformation) occurrence which led to strength reduction.The ultimate behaviors such as fracture mode,ultimate strength are compared with those predicted by current design codes.Further,conditions of curling occurrence and the strength reduction due to curling are investigated and modified strength equations are suggested considering the curling effect.

  3. Stresses In Vehicle Chassis Joints - A Canparison Of SPATE With Other Analysis Techniques

    Science.gov (United States)

    Loader, A. J.; Turner, W. B.; Harwood, N.

    1987-04-01

    Joints in ladder frame chassis have been studied as part of an SERC Teaching Company Schene. The joints between the cross members and side members are complex structures involving bolts, welds and/or rivets, as the cross member section can be tubular, box or C-section. It is therefore difficult to apply simple analytical methods to such joints. This paper compares the stresses obtained by brittle lacquer, strain gauge and SPATE measurements with those found from a finite elenent analysis of the joints.

  4. Assessing the effects of insufficient rebar and missing grout in grouted rock bolts using guided ultrasonic waves

    Science.gov (United States)

    Cui, Y.; Zou, D. H.

    2012-04-01

    One of the challenges in field monitoring of grouted rock bolts, which normally have a short exposed end, is to detect the defects of the bolt or grout. In this paper, grouted rock bolts are studied using guided ultrasonic waves. Numerical modeling for grouted rock bolts is performed to assess the effects of insufficient rebar and missing grout. The numerical results are verified with laboratory tests on rock bolt samples. With introduction of correction factors at the reflection end, the results indicate that it is practically possible to identify insufficient rebar and grout defects with guided ultrasonic signals received at the exposed end. It also indicates that with the attenuation and wave velocity of guided waves, defective rock bolts with insufficient rebar length or missing grout in the ground can be detected with reasonable accuracy.

  5. Lubrication properties of silver-palladium alloy prepared by ion plating method for high temperature stud bolt

    Institute of Scientific and Technical Information of China (English)

    Jung-Dae KWON; Sunghun LEE; Koo-Hyun LEE; Jong-Joo RHA; Kee-Seok NAN; Se-Hun KWON

    2011-01-01

    As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature studbolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.

  6. Improving boiler foundation bolt installation technology%提高锅炉地脚螺栓安装工艺

    Institute of Scientific and Technical Information of China (English)

    李晓峰

    2014-01-01

    阐述了锅炉地脚螺栓安装前的准备工作,通过对螺栓安装施工工艺流程的介绍,分析了提高螺栓与螺栓支架安装精度的方法,并对检验螺栓安装质量的技术要点作了研究,以确保锅炉地脚螺栓安装的正确无误。%The paper illustrates boiler foundation bolt installation preparations. Through introducing bolt installation technology procedures, it analyzes methods of improving bolt and bolt support installation accuracy, and studies technological points of examining bolt installation quality, with a view to guarantee boiler foundation bolt installation correct.

  7. A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections.

    Directory of Open Access Journals (Sweden)

    Muhammad Nasir Amin

    Full Text Available Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the "Extended Hollo-Bolt" (EHB due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach.

  8. European development Rock bolting; Desarrollo Europeo del Bulonaje

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    The project European Development Rockbolting which was developed during the period 1994-1997 and carried out within the OCICARBON Action Program (OCICARBON-ITGE agreement dated September 1, 1994, Code C-13-438) as well as within the framework of the Coal Technical research Program of the D. G. XVII of the EEC, n 7220/AB/143. The project has had the following external partners: DMT (Germany), BCC (UK) and CDF (France), and the collaboration of INERIS (France), RMT (UK) and GEOCONTROL S. A. (Spain). The objective of the investigation was to improve the techniques and design currently used in the application of rockbolts for supporting of both infrastructure and beds in the European coal mining. The most important result, besides that derived from the sharing of experiences and knowledge, was the technological design of a supporting system, which was carried out by each partner for the various proposed exploitations. The Spanish part carried out the works of designing and estimation of the bolting system corresponding to the exploitations of: -Carbones de Pedraforca SA. Saldes mine. -U. E. Provence. Pit Y. Morandat.

  9. Joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret......Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret...

  10. Joint ventures

    NARCIS (Netherlands)

    M.N. Hoogendoorn (Martin)

    2009-01-01

    textabstractEen veel voorkomende wijze van samenwerking tussen ondernemingen is het uitvoeren van activiteiten in de vorm van een joint venture. Een joint venture is bijna altijd een afzonderlijke juridische entiteit. De partners in de joint venture voeren gezamenlijk de zeggenschap uit. In internat

  11. Coracoclavicular joint

    International Nuclear Information System (INIS)

    The coracoclvicular joint, a rear abnormality which may be the cause of pain in the shoulder and limitation of motion of the shoulder joint, is discussed. A case of coracoclvicular joint with shoulder pain was observed in 65 yrs old Korean male

  12. Grout quality and its impact on guided ultrasonic waves in grouted rock bolts

    Science.gov (United States)

    Zou, D. H. Steve; Cheng, Jiulong; Yue, Renjie; Sun, Xiaoyun

    2010-10-01

    Rock bolts are widely used in mining and geotechnical engineering as ground anchorage. The supporting capacity of grouted rock bolts depends greatly on the grout quality in rocks. Measurement of the grout quality in the field is an outstanding issue. In an effort to develop a non-destructive method for estimating the grout quality of grouted rock bolts, the characteristics of guided ultrasonic waves are investigated in this paper. Particular attention is paid to the effects of grout quality on group wave velocity and attenuation. Issues associated to grout quality and bolt failure are also discussed. To simulate the in-situ condition, several specimens were prepared using 20 mm diameter rebar. Each specimen was grouted in a 200 mm diameter concrete cylinder, which was designed with different compressive strength. A large number of tests were conducted on these specimens using ultrasonic waves with frequencies from 10 to 100 kHz. The effects of air content and compressive strength of the grout on attenuation and group velocity of ultrasonic waves in the grouted rock bolts were studied. The results showed large influence from the grout strength and air content and demonstrated the potential for using ultrasonic waves to test grout quality.

  13. International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

    Science.gov (United States)

    Sievers, Daniel E.; Warden, Harry K.

    2010-01-01

    A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism. The mechanism that effects the structural connection of the Common Berthing Mechanism halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per Common Berthing Mechanism. The Common Berthing Mechanism has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface (Figure 1). The Powered Bolt Assemblies are preloaded to approximately 84.5 kN (19000 lb) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes that create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

  14. Submillimeter bolt location in car bodywork for production line quality inspection

    Science.gov (United States)

    Altamirano-Robles, Leopoldo; Arias-Estrada, Miguel; Alviso-Quibrera, Samuel; Lopez-Lopez, Aurelio

    2000-03-01

    In the automotive industry, a vehicle begins with the construction of the vehicle floor. Later on, several robots weld a series of bolts to this floor which are used to fix other parts. Due to several problems, like welding tools wearing, robot miscalibration or momentary low power supply, among others, some bolts are incorrectly positioned or are not present at all, bringing problems and delays in the next work cells. Therefore, it is of importance to verify the quality of welded parts before the following assembly steps. A computer vision system is proposed in order to locate autonomously the presence and quality of the bolts. The system should carry on the inspection in real time at the car assembly line under the following conditions: without touching the bodywork, with a precision in the submillimeter range and in few seconds. In this paper we present a basic computer vision system for bolt location in the submillimeter range. We analyze three arrangements of the system components (camera and illumination sources) that produce different results in the localization. Results are presented and compared for the three approaches obtained under laboratory conditions. The algorithms were tested in the assembling line. Variations up to one millimeter in the welded position of the bolts were observed.

  15. Numerical simulation of the effect of coupling support of bolt-mesh-anchor in deep tunnel

    Institute of Scientific and Technical Information of China (English)

    SUN Xiao-ming; CAI Feng; YANG Jun; CAO Wu-fu

    2009-01-01

    The mechanical effects of bolt-mesh-anchor coupling support in deep tunnels were studied by using a numerical method, based on deep tunnel coupling supporting techniques and non-linear deformation mechanical theory of rock mass at great depths. It is shown that the potential of a rigid bolt support can be efficiently activated through the coupling effect between a bolt-net support and the surrounding rock. It is found that the accumulated plastic energy in the surrounding rock can be sufficiently transformed by the coupling effect of a bolt-mesh-tray support. The strength of the surrounding rock mass can be mobilized to control the deformation of the surrounding rock by a pre-stress and time-space effect of the anchor support. The high stress transformation effect can be realized by the mechanical coupling effect of the bolt-mesh-anchor support, whereby the force of the support and deformation of the surrounding rock tends to become uniform, leading to a sustained stability of the tunnel.

  16. Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa.

    Science.gov (United States)

    Zhang, Y W; Guo, M H; Tang, X B; Jin, D; Fang, Z Y

    2016-01-01

    Bolting and flowering are key processes during the growth and development of Chinese cabbage (Brassica rapa L. ssp pekinensis). Understanding the molecular mechanisms underlying bolting and flowering is of significance for improving production of the vegetable. A leaf-color change from bright green to gray-green has been observed following differentiation of the flowering stem and before bolting in the vegetable, and is considered to be a signal for bolting. Proteomics in meristem tissues of an inbred line (C30) were analyzed by two-dimensional electrophoresis during the transition period. We found that some proteins were specifically expressed while others were differentially expressed. Among these, 17 proteins were specifically expressed before the color change, 18 were specifically expressed after the color change, 21 were downregulated during the color change, and 29 were upregulated. Mass spectrometric analysis (MALDI-TOF-TOF/MS) was used to analyze 17 protein spots, and four proteins (subunit E1 of vacuolar-type H+ transporter ATPase, the large subunit of Rubicon, S-adenosylmethionine synthetase, and tubulin α-2) were identified. qPCR analysis was conducted to quantify the expression of genes encoding these proteins during the transitional period. The expression of BrVHA-E1, BrSAMS, BrrbcL, and BrTUA6 was significantly different before and after the leaf-color change, suggesting that these genes might be involved in regulating flower differentiation and bolting. PMID:27525926

  17. 应力波干涉配合螺接%Stress wave intervening concerted bolt connection

    Institute of Scientific and Technical Information of China (English)

    杨亚文; 李淑萍; 段宝

    2001-01-01

    This paper introduces the importance of fatigue life to the quality of products and the effect of intervening parametre on fatigue life. The method is also proposed on making thread-hole and bolt in interving concerted process, bolt connection as well. In the meantime a new connection method called stress wave bolt connection is introduced.%主要介绍了疲劳寿命对产品质量的重要性,干涉量对疲劳寿命的影响。干涉配合螺接过程中螺孔和螺栓的加工方法以及螺栓的安装方法。另外,还介绍了一种新的干涉配合螺接方法——应力波螺接。

  18. Review Paper on Performance Evaluation of Nut and Bolt Recognition System Using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Shruti Paunikar

    2013-09-01

    Full Text Available There is constant research going on in the field of recognition by means of artificial intelligence to enhance the productivity. The automotive industry requires an automated system to sort different sizes and shapes nut and bolt which are the mainly used component in the industry, to improve the overall productivity. This review paper deals with some feature extraction techniques and its performance impact on the artificial neural network efficiency for the recognition of nut and bolt. The main feature extraction techniques analysed for this review paper are stationary wavelet transform, principle component analysis and radius analysis. The aforementioned techniques are already tested and simulation is done on MATLAB.The results obtained varies depending on pre-processing techniques used for the nut and bolt recognition.

  19. Investigation of corrosion and stress corrosion cracking in bolting materials on light water reactors

    International Nuclear Information System (INIS)

    Laboratory experiments performed at BNL have shown that the concentration of boric acid to a moist paste at approximately the boiling point of water can produce corrosion rates of the order of several tenths of an inch per year on bolting and piping materials, which values are consistent with service experience. Other failure evaluation experience has shown that primary coolant/lubricant interaction may lead to stress corrosion cracking (SCC) of steam generator manway studs. An investigation was also performed on eleven lubricants and their effects on A193 B7 and A540 B24 bolting materials. H2S generation by the lubricants, coefficient of friction results and transgranular SCC of the bolting materials in steam are discussed. 13 refs

  20. Ultrasonic Inspection of Cracks in Stud Bolts of Reactor Vessels in Nuclear Power Plants by Signal Processing of Differential Operation

    International Nuclear Information System (INIS)

    The stud bolt is one of crucial parts for safe operation of reactor vessels in nuclear power plants, Crack initiation and propagation were reported in stud bolts that arc used for closure of reactor vessel and head, Stud bolts are inspected by ultrasonic technique during overhaul periodically for the prevention of stud bolt failure which could induce radioactive leakage from nuclear reactor, In conventional ultrasonic testing for inspection of stud bolts, cracks are detected by using shadow effect It takes too much time to inspect stud bolts by using conventional ultrasonic technique. In addition, there were numerous spurious signals reflected from every oblique surfaces of thread, In this study, the signal processing technique for enhancing conventional ultrasonic technique was introduced for inspecting stud bolts. The signal processing technique provides removing spurious signal reflected from every oblique surfaces of thread and enhances detectability of defects. Detectability for small crack was enhanced by using this signal processing in ultrasonic inspection of stud bolts in Nuclear Power Plants

  1. Handbook on dynamics of jointed structures.

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Nicoli M.; Lauffer, James P.; Jew, Michael D.; Segalman, Daniel Joseph; Gregory, Danny Lynn; Starr, Michael James; Resor, Brian Ray

    2009-07-01

    The problem of understanding and modeling the complicated physics underlying the action and response of the interfaces in typical structures under dynamic loading conditions has occupied researchers for many decades. This handbook presents an integrated approach to the goal of dynamic modeling of typical jointed structures, beginning with a mathematical assessment of experimental or simulation data, development of constitutive models to account for load histories to deformation, establishment of kinematic models coupling to the continuum models, and application of finite element analysis leading to dynamic structural simulation. In addition, formulations are discussed to mitigate the very short simulation time steps that appear to be required in numerical simulation for problems such as this. This handbook satisfies the commitment to DOE that Sandia will develop the technical content and write a Joints Handbook. The content will include: (1) Methods for characterizing the nonlinear stiffness and energy dissipation for typical joints used in mechanical systems and components. (2) The methodology will include practical guidance on experiments, and reduced order models that can be used to characterize joint behavior. (3) Examples for typical bolted and screw joints will be provided.

  2. Pneumatically-powered hand tool used for cutting bolts during bone-fixing in surgery

    OpenAIRE

    Cool, J.C.; Rijnsaardt K.A.

    1996-01-01

    Abstract of NL 1000849 (C2) The tool has at least one pneumatic motor (1a, 1b), transmission (2) and regulator. The motor(s) can be of the piston and cylinder type producing reciprocating motion or of the rotary type. The tool is powered by a commercially-available gas cylinder containing 16g of CO2 at a pressure of 56 bar. Illustrated is a surgical implement to crop bone-fixing bolts. The bolt end is inserted in the hole (7) to enter the eccentric bore (9) of the inner rod (8). The rod rotat...

  3. Ultrasonic measurement on RPV stud-bolt loading under hot transient of Qinshan NPP

    International Nuclear Information System (INIS)

    It is a continuation of research work for sealing analysis and tests on the PRV of PWR. It expounds that the key of solving thermal transient sealing problem lies in giving the thermal increment of stud-bolt fatigue life and transient loading spectrum for vessel analysis. The authors recounted the fundamental works and main results of ultrasonic measurement on RPV stud-bolt loading on the reactor of Qinshan Nuclear Power Plant. The measuring capability exceeds 1 m length and 300 degree C temperature. Therefore, it is possible to be used in the field of NPP

  4. Stud-bolts strength for cell-liner design under shearing deformation

    International Nuclear Information System (INIS)

    This paper presents experimental and analytical stud-bolt strength subjected to large shearing deformation at high temperature. Tensile test result of the material, SM41B, was shown in the range of room temperature to 550degC at 10-3 and 10-4 m/m/s in strain rate. Shearing fracture test result of the stud-bolt is shown at room temperature and 530degC. Shearing fracture criterion was discussed based on both test results and FEM analysis result. (author)

  5. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments.

    Science.gov (United States)

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C-14 h and 25°C/18°C-14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb formation under 20

  6. The Extended Thermodynamic Phase Structure of Taub-NUT and Taub-Bolt

    CERN Document Server

    Johnson, Clifford V

    2014-01-01

    We study aspects of the extended gravitational thermodynamics for the Taub-NUT and Taub-Bolt geometries in four dimensional locally anti-de Sitter spacetime, where the cosmological constant is treated as a dynamical pressure. Attention is paid to the phase structure in the (p,T) plane, which has a line of first order phase transitions extending from the origin. We argue for a dynamical interpretation of the unstable physics in the negative specific heat region. A deformation corresponding to a dyonic Taub-NUT/Bolt system is also explored, and the effect of the deformation on the phase diagram is characterised.

  7. Theoretical Calculation and Analysis on the Composite Rock-Bolt Bearing Structure in Burst-Prone Ground

    Directory of Open Access Journals (Sweden)

    Liang Cheng

    2015-01-01

    Full Text Available Given the increase in mining depth and intensity, tunnel failure as a result of rock burst has become an important issue in the field of mining engineering in China. Based on the Composite Rock-Bolt Bearing Structure, which is formed due to the interaction of the bolts driven into the surrounding rock, this paper analyzes a rock burst prevention mechanism, establishes a mechanical model in burst-prone ground, deduces the strength calculation formula of the Composite Rock-Bolt Bearing Structure in burst-prone ground, and confirms the rock burst prevention criterion of the Composite Rock-Bolt Bearing Structure. According to the rock burst prevention criterion, the amount of the influence on rock burst prevention ability from the surrounding rock parameters and bolt support parameters is discussed.

  8. 煤矿建井施工锚杆支护探析%Built on Coal Mine Well Construction Bolting

    Institute of Scientific and Technical Information of China (English)

    王丹净

    2013-01-01

    This paper built around the coal mine well construction bolting, introduced the principle of the bolt supporting role; analysis to identify bolting parameters, the existing several bolting design method for advantages and disadvantages analysis; this paper discusses how to for bolting project construction and inspection.%文章围绕煤矿建井施工锚杆支护,介绍了锚杆支护的作用原理;分析确定锚杆支护参数,对目前存在的几种锚杆支护设计方法进行优缺点分析;阐述如何进行锚杆支护工程的施工和检验。

  9. The strength of glued-in bolts after 9 years in situ loading. An investigation of fatigue loaded glued-in bolts from the blade-to-hub connection of the Nibe Windmill-B

    Energy Technology Data Exchange (ETDEWEB)

    Uhre Pedersen, M.; Clorius, C.O.

    1995-07-01

    In 1993 one of the three 2.5 t blades from the 20 m radius rotor of the Nibe-B windmill was struck by lightning and subsequently dismounted. The blades had a solid leading edge of glulam and each blade was connected to the hub by 28 glued-in bolts arranged circumferentially in the root section. The mishap offered a unique opportunity to investigate the residual strength of the glued-in bolts after 9 years of oscillating load including a total of 5.0 10{sup 7} cycles. The bolts investigated have a hollow tapering. This geometry was developed at the Department of Structural Engineering and has been reported to give a 20% higher load bearing capacity than similar solid bolts. The holes in the glulam were 2 mm oversized and an epoxy glue was used to bond the shot blasted bolts to the glulam. A test specimen was cut from the root section of one blade. This produced a 0.8 m high solid glulam cylinder with a diameter of 0.86 m containing the 28 glued-in bolts. A 500 kN servo hydraulic double acting actuator delivered the pull-out force at the circumferential position of the bolts, and a hydraulic press delivered a counter force at the centre of the test specimen. The displacement of the actuator piston was used to control the pull-out tests. The time from test start to bolt failure was approximately 4 minutes. A total of 11 bolts were pulled out between undamaged bolts. The mean strength of these bolts was found to be 362 kN with a standard deviation of 37 kN. When comparing this mean residual strength with previously recorded test data a 5% strength reduction was observed. The force displacement curves showed no plastic capacity in the connections. A displacement between 0.4 mm and 1.0 mm was observed at fracture. The bolts pulled out between failed bolts showed a surprisingly high mean residual strength of 304 kN. (EG) 14 refs.

  10. Development of a hybrid dome composed of glued-laminated timbers and steel cables. (Part 3). ; Bending tests of the glulam joint. Daidanmen shuseizai to cable ni yoru hybridter dot dome kozo no kaihatsu. 3. ; Daidanmen shuseizai setsugobu no mage saika jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, N.; Tsubota, H.; Maruyama, N.; Kobayashi, H. (Kajima Corp., Tokyo (Japan))

    1991-10-31

    As a part of the development of the large scale hybrid dome (140 m in diameter, 49 m in height) composed of glued-laminated timbers (glulam) and steel cables, bending tests of full-size glulam joints with steel plates and bolts were conducted to evaluate the bending moment capacity of the joint. As a result, the observed ultimate bending moment capacities of all the joint specimens were larger than the designed ones, and all the specimens failed with splits in the glulam along bolt rows in a tensile zone due to either strong or weak-axial bending. Adhesive enhanced the bending rigidity of the joint in the weak axis, relaxing slightly radical failure. The specific bolt was subjected to tensile force through bending in the strong axis, while all the bolts equally subjected to tensile force in the weak axis. It was rational to design wooden joints by applying the AIJ (Architectural Institute of Japan) standard under the appropriate assumption of the force distribution among members of a bolt group. 2 refs., 11 figs., 2 tabs.

  11. Pull-out test of stud bolts embedded in concrete under an in-plane force

    International Nuclear Information System (INIS)

    There are many steel plates with stud bolts embedded in the R C walls of a nuclear reactor building to support equipment and piping. Under a earthquake, the steel plates are submitted to an out-of-plane force due to the inertia force acting upon equipment and piping. Furthermore, the walls are submitted to an in-plane force, and cracks may occur. A large number of experimental studies have been carried out on the pull-out strength of stud bolts embedded in concrete. Few studies have been performed to understand the strength of stud bolts embedded in concrete under an in-plane force and, further, not any one on the strength for concrete under in-plane force simultaneously to stud bolts under out-of-plane force. This paper describes a test performed to understand the pull-out strength determined by this interaction of in-plane and out-of-plane forces. (author). 5 refs., 9 figs., 5 tabs

  12. Fewer complications with bolt-connected than tunneled external ventricular drainage

    DEFF Research Database (Denmark)

    Jensen, Torben Slott; Carlsen, Jakob Gram; Sørensen, Jens Christian;

    2016-01-01

    BACKGROUND: Ventriculostomy/external ventricular drain (EVD) is a common neurosurgical procedure. Various techniques are used to fixate the drain and the objective of this study was, in a retrospective setting, to compare the incidence of complications when using bolt-connected EVD (BC-EVD) versus...

  13. Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

    Science.gov (United States)

    Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

    2010-11-01

    Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect. PMID:20393855

  14. Residual Strength of Glued-in Bolts After 9 Years In Situ Loading

    DEFF Research Database (Denmark)

    Pedersen, Martin Bo Uhre; Clorius, Christian Odin; Damkilde, Lars;

    1996-01-01

    In 1993 one of the wooden blades of the Nibe-B windmill was struck by lightning and subsequently demounted after 9 years of use. The mishap offered a unique opportunity to investigate the residual strength of the 28 glued-in bolts used to form the blade to rotor hub connection.The test method...

  15. Velocity dispersions in a cluster of stars: How fast could Usain Bolt have run?

    CERN Document Server

    Eriksen, H K; Langangen, O; Wehus, I K

    2008-01-01

    Since that very memorable day at the Beijing 2008 Olympics, a big question on every sports commentator's mind has been "What would the 100 meter dash world record have been, had Usain Bolt not celebrated at the end of his race?" Glen Mills, Bolt's coach suggested at a recent press conference that the time could have been 9.52 seconds or better. We revisit this question by measuring Bolt's position as a function of time using footage of the run, and then extrapolate into the last two seconds based on two different assumptions. First, we conservatively assume that Bolt could have maintained Richard Thompson's, the runner-up, acceleration during the end of the race. Second, based on the race development prior to the celebration, we assume that he could also have kept an acceleration of 0.5 m/s^2 higher than Thompson. In these two cases, we find that the new world record would have been 9.61 +/- 0.04 and 9.55 +/- 0.04 seconds, respectively, where the uncertainties denote 95% statistical errors.

  16. The baffle-barrel-bolting analysis program: evolution and technical accomplishments

    Energy Technology Data Exchange (ETDEWEB)

    Schwirian, R.E.; Forsyth, D.R.; Snyder, M.D.; Bhandari, D.R.; Barsic, J.A.; Rabenstein, W.D. [Westinghouse Electric Company, Pittsburgh, Pennsylvania (United States)

    2001-07-01

    In Westinghouse pressurized water reactors (PWR) the reactor core is surrounded by baffle plates, which provide lateral restraint for the fuel assemblies at the core boundary. Baffle plates are attached to horizontal supports called former plates by baffle-former bolts. The formers are attached to the core barrel which also provides vertical support for the core. The B3 analysis program addresses the possibility of reduced baffle-former bolting in Westinghouse U.S. domestic plant designs with respect to the relevant design criteria. Since safety is the overriding motivation for the program, faulted events have received the most in-depth attention. This focus has been reinforced by the fact that the loads produced by the loss-of-coolant-accident (LOCA) have usually been the most limiting of all those considered. Consequently, much of the presentation below deals with the development of analysis techniques and acceptance criteria to demonstrate that LOCA-induced loads on the bolts and the fuel assemblies will be acceptable with significantly reduced baffle-former bolting. A discussion of the other faulted, normal, and upset analyses performed as part of the program will also be presented. (author)

  17. Numerical simulation of creep characteristics of soft roadway with bolt-grouting support

    Institute of Scientific and Technical Information of China (English)

    王连国; 李海亮; 张健

    2008-01-01

    Based on the engineering background of a soft rock roadway in Qinan Coal Mine 82 Area,Huaibei Mining Group,three creep models with different support patterns in soft rock roadway were established by using geotechnical software of FLAC2D.According to the calculation results of different models,the change law of mechanical properties with the time of bolt-grouting support structure was obtained.Furthermore,for the test bolt-grouting support roadway,the deformation law of surrounding rock got by underground industrial experiment and field observation accords with the creep law got by numerical calculation.The results of numerical calculation and field observation show that,compared with other supports,the creep of bolt-grouting support roadway enters the steady-state creep stage from tertiary creep stage ahead,the deformations of roof,floor and two sides are decreased greatly,the plastically deforming area in surrounding rock is reduced obviously,and the distribution ranges of maximum and minimum principal stress are shrank obviously.All those fully show that the bolt-grouting support has its remarkable advantages in controlling surrounding rock creep and improving the whole strength of surrounding rock and self-bearing capacity.

  18. Influence of strengthening and repair schemes on dowel type timber joints and moment resisting frames

    OpenAIRE

    Yang, Jiaqi; 楊家琦

    2013-01-01

    Timber has been a widely used construction material throughout the history of human development and it is still popular to this day. Timber frames are a common structural form used in historical and modern day structures. An effective means to connect timber members together is via bolts or dowels due to their high strength, ductile behaviour and flexibility in application. Such joints are, however, vulnerable and prone to damage especially during seismic attacks. In order to improve the perf...

  19. Tethered Space Satellite-1 (TSS-1): Wound About a Bolt

    Science.gov (United States)

    O'Connor, Brian; Stevens, Jennifer

    2016-01-01

    integration of the hardware into the Shuttle payload bay. An analysis, called Coupled loads analysis, incorporates any updates to the model due to system level tests of all the different payloads, and any changes that were found during integration. Engineering analysis examines the worst case scenarios for the loads the hardware will see. The two times during the mission where the dynamic loads are the worst were 1) the first 10-second portion of Shuttle lift off, and 2) a 2-second time during landing when the landing gears hit the ground. The coupled loads analysis using the final verification loads showed that a single bolt attaching the deployer reel mechanism to the support structure had a "negative margin" - which is an indication that it might fail - during touch down. Hardware certification rules do not allow for hardware to fly with negative margins. A structural failure of one payload could have serious or catastrophic consequences to other payloads, or may significantly damage the Orbiter. The issue had to be resolved before the flight.

  20. Bacterial artificial chromosome-derived molecular markers for early bolting in sugar beet.

    Science.gov (United States)

    Gaafar, R M; Hohmann, U; Jung, C

    2005-04-01

    Early bolting in sugar beet (Beta vulgaris L.) is controlled by the dominant gene B. From an incomplete physical map around the B gene, 18 bacterial artificial chromosomes (BACs) were selected for marker development. Three BACs were shotgun-sequenced, and 61 open reading frames (ORFs) were identified. Together with 104 BAC ends from 54 BACs, a total number of 55,464 nucleotides were sequenced. Of these, 37 BAC ends and 12 ORFs were selected for marker development. Thirty-one percent of the sequences were found to be single copy and 24%, low copy. From these sequences, 15 markers from ten different BACs were developed. Ten polymorphisms were determined by simple agarose gel electrophoresis of either restricted or non-restricted PCR products. Another five markers were determined by tetra-primer amplification refractory mutation system-PCR. In order to select candidate BACs for cloning the gene, genetic linkage between seven markers and the bolting gene was calculated using 1,617 plants from an F2 population segregating for early bolting. The recombination values ranged between 0.0033 and 0.0201. In addition, a set of 41 wild and cultivated Beta accessions differing in their early bolting character was genotyped with seven markers. A common haplotype encompassing two marker loci and the b allele was found in all sugar beet varieties, indicating complete linkage disequilibrium between these loci. This suggests that the bolting gene is located in close vicinity to these markers, and the corresponding BACs can be used for cloning the gene.

  1. Failure of dissimilar material bonded joints

    Science.gov (United States)

    Konstantakopoulou, M.; Deligianni, A.; Kotsikos, G.

    2016-03-01

    Joining of materials in structural design has always been a challenge for engineers. Bolting and riveting has been used for many years, until the emergence of fusion welding which revolutionised construction in areas such as shipbuilding, automotive, infrastructure and consumer goods. Extensive research in the past 50 years has resulted in better understanding of the process and minimised the occurrence of failures associated with fusion welding such as, residual stress cracking, stress corrosion and corrosion fatigue cracking, localised reduction in mechanical properties due to microstructural changes (heat affected zone) etc. Bonding has been a technique that has been proposed as an alternative because it eliminates several of the problems associated with fusion welding. But, despite some applications it has not seen wide use. There is however a renewed interest in adhesively bonded joints, as designers look for ever more efficient structures which inevitably leads to the use and consequently joining of combinations of lightweight materials, often with fundamentally different mechanical and physical properties. This chapter provides a review of adhesively bonded joints and reports on improvements to bonded joint strength through the introduction of carbon nanotubes at the bond interface. Results from various workers in the field are reported as well as the findings of the authors in this area of research. It is obvious that there are several challenges that need to be addressed to further enhance the strength of bonded joints and worldwide research is currently underway to address those shortcomings and build confidence in the implementation of these new techniques.

  2. Linkage Map Construction and Quantitative Trait Loci Analysis for Bolting Based on a Double Haploid Population of Brassica rapa

    Institute of Scientific and Technical Information of China (English)

    Xu Yang; Yang-Jun Yu; Feng-Lan Zhang; Zhi-Rong Zou; Xiu-Yun Zhao; De-Shuang Zhang; Jia-Bing Xu

    2007-01-01

    Early bolting of Chinese cabbage (Brassica rapa L.) during spring cultivation often has detrimental effects on the yield and quality of the harvested products. Breeding late bolting varieties is a major objective of Chinese cabbage breeding programs. in order to analyze the genetic basis of bolting traits, a genetic map of B. rapa was constructed based on amplified fragment-length polymorphism (AFLP), sequence-related amplified polymorphism (SRAP), simple sequence repeat (SSR), random amplification of polymorphic DNA (RAPD), and isozyme markers. Marker analysis was carried out on 81 double haploid (DH) lines obtained by mlcrospore culture from F1 progeny of two homozygous parents: B. rapa L. ssp. pekinensis (BY) (an extra-early bolting Chinese cabbage line) and B. rapa L. ssp. rapifera (MM) (an extra-late bolting European turnip line). A total of 326 markers including 130 AFLPs, 123 SRAPs, 16 SSRs, 43RAPDs and 14 isozymes were used to construct a linkage map with 10 linkage groups covering 882 cM with an average distance of 2.71 cM between loci. The bolting trait of each DH line was evaluated by the bolting index under controlled conditions. Quantitative trait loci (QTL) analysis was conducted using multiple QTL model mapping with MapQTL5.0 software. Eight QTLs controlling bolting resistance were identified. These QTLs, accounting for 14.1% to 25.2% of the phenotyplc variation with positive additive effects, were distributed into three linkage groups. These results provide useful information for molecular marker-assisted selection of late bolting traits in Chinese cabbage breeding programs.

  3. Joint pain

    Science.gov (United States)

    ... or conditions. It may be linked to arthritis , bursitis , and muscle pain . No matter what causes it, ... Autoimmune diseases such as rheumatoid arthritis and lupus Bursitis Chondromalacia patellae Crystals in the joint: gout (especially ...

  4. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and review of the literature

    Institute of Scientific and Technical Information of China (English)

    Sameer Aggerwal; Nitesh Gahlot; Uttam C. Saini; Kamal Bali

    2011-01-01

    Breakage of locking bolts is an important cause of interlocking nail failure in femoral fractures. It usually occurs in the form of single breakage in one of the distal bolts of the nail or nail breakage around the distal locking hole. Here we report an unusual case of intramedullary femoral nail failure with segmental breakage of both the distal locking bolts. Such a scenario usually complicates further management. We successfully managed this case with exchange nailing without bone grafting. Here we briefly reviewed the literature regarding such an unusual presentation and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation.

  5. Applied on bolting-cable anchor support of full-seam roadway in weaker thick coal seam

    Institute of Scientific and Technical Information of China (English)

    赵庆彪; 张生华; 郭励生

    2003-01-01

    The designing method and the supporting mechanism of both bolt and small cable anchor for full-seam roadway in the weaker thick coal seam are systematically analyzed, and the construction technology and the supporting results are briefly summarized.

  6. Non-Destructive Evaluation of Rock Bolts Associated With Optical Strain Sensors at the Homestake Gold Mine

    Science.gov (United States)

    Kogle, M. M.; Fratta, D.; Wang, H. F.; Geox^Tm

    2010-12-01

    Fiber-Bragg Grating (FBG) optical strain sensors have been installed in the former Homestake Gold Mine (Lead, SD) as part of an early science project at the Deep Underground Science and Engineering Laboratory (DUSEL). FBG sensors are anchored within an alcove at the 4100’ level of the mine using rock bolts and coupled to the rock mass with resin epoxy and cement grout. The quality of the coupling between the rock bolt and the rock mass is essential to assure that true rock mass strains are being recorded. To evaluate the integrity of the installed rock bolt system, guided ultrasonic waves can be used as a non-destructive monitoring system. The propagation of reflected ultrasonic waves capture information about the degree of coupling between the steel rock bolt and resin epoxy/cement grout and between the resin epoxy/cement grout and the surrounding rock mass, and hence the integrity of the installed rock bolt system. In this study, we use the phase velocity obtained from ultrasonic wave propagation to estimate the rock modulus. In our initial testing we generated a broadband elastic wave along the length of a rock bolt anchored in a concrete cylinder while monitoring multiple reflections with a single accelerometer affixed at the exposed end of the rock bolt. The captured waveforms include several reflections that were then analyzed to obtain frequency response, coherence, phase velocity, and damping between multiple reflections. As the wavelength increases, the response captures first elastic properties of the steel and then the combined elastic properties of the rock bolt/rock mass system. Challenges associated with implementing this non-destructive testing technique in rock masses include the generation of wide bandwidth signals having enough strength to produce multiple reflections with high enough signal-to-noise ratios to capture properties of multi-scale systems.

  7. Effect of pre-tensioned rock bolts on stress redistribution around a roadway insight from numerical modeling

    Institute of Scientific and Technical Information of China (English)

    GAO Fu-qiang; KANG Hong-pu

    2008-01-01

    The importance of the pre-tensioned force of rock bolts has been recognized by more and more researchers. To investigate the effect of pre-tensioned rock bolts on stress redistribution around roadways, a numerical analysis was carded out using FLAC3D and a special post-process methodology, using surfer, is proposed to process the numerical simulation results. The results indicate that pre-tensioned rock bolts have a significant effect on stress redistribution around a roadway. In the roof, pre-tensioned rock bolts greatly increase vertical stress; as a result, the strength of the rock mass increased significantly which results in a greater capacity of bearing a large horizontal stress. The horizontal stress decreases in the upper section of the roof, indicating that pre-tensioned rock bolts significantly reduce the coefficient and the size of the region concentration of horizontal stress. At the lateral side, pre-tensioned rock bolts greatly increase the horizontal stress; therefore, the rock mass strength significantly increases which results also in a greater capacity of bearing a large vertical stress. The greater the size of pre-tensioned force, the larger the region of stress redistribution around a roadway is affected and the higher the size of the stress on the roadway surface the more the rock mass strength increases.

  8. Failure analysis of the stud bolt of a canned motor pump of heavy water plant, Talcher

    International Nuclear Information System (INIS)

    Detailed investigations have been carried out on the failed stud bolts (made of DIN 1.4021 X 20Cr 13) of a canned motor pump of Heavy Water Plant, Talcher, using metallographic, microhardness testing, scanning electron microscopy and electron probe micro-analysis(EPMA) techniques. The studs had failed in a brittle manner in the mid-length portion. The origin of the fracture has been identified to be a corroded region on the stud surface. Branching cracks propagating through silicon rich inclusions have been noted. Two types of inclusions, one containing Mn and S and other containing S, Mn and O2 have been found in the material. Clusters of large and small inclusions of the above types have been found near the origin of the fracture. It has been concluded that the fracture was caused by corrosion fatigue, initiating at the cluster of inclusions present on the surface of the stud bolts. (author). 7 refs., 5 figs

  9. Contact Stress Analysis around Elliptical Bolt-loaded Hole in Orthotropic Plates

    Directory of Open Access Journals (Sweden)

    O. Aluko

    2012-12-01

    Full Text Available The practicality of changing the bolt shape from circular to elliptical under friction effects in order to reduce the contact stress distributions was analytically investigated. The analysis utilized the complex stress functions obtained from the assumed displacement expressions that satisfy the boundary conditions around the hole to determine the contact stresses. In the method of solution coulomb friction was used to determine the prescribed displacements at the boundary. The material properties of graphite/epoxy and carbon fiber reinforced plastics laminates were used in this investigation and the results compared with available literature. It was revealed that the stress distributions followed the same pattern in both geometries but with lower magnitude in elliptical shape and the reduction in stress distributions caused by changing the bolt shape from circular to elliptic depend on friction coefficient.

  10. Rock mass movements around development workings in various density of standing-and-roof-bolting support

    Institute of Scientific and Technical Information of China (English)

    MAJCHERCZYK Tadeusz; MALKOWSKLI Piotr; NIEDBALSKI Zbighiew

    2008-01-01

    Presented measurement results of roof rocks and wall rock movements of un-derground development workings after their drifting. The research was carried out in thecoal mine workings with standing-and-roof bolting support. There were various density ofthe support, so the aim of the special monitoring programme was to determine movementintensity of rock mass in the premises of the heading area. There were four types of re-search did by the authors. They measured convergence, roof layers separation using tell-tales and sonic probes and load bearing of the headings' roofs by hydraulic dynamometers.Evaluation of fracture zone around the heading and investigation the load zone caused byfailed roof rocks may become a basement for the determination of support parameters ofthe workings. The combined system of standing support and roof bolting seems to be anessential for underground headings protection.

  11. Variety Seeking, Purchase Timing, and the "Lightning Bolt" Brand Choice Model

    OpenAIRE

    Pradeep K. Chintagunta

    1999-01-01

    The "Lightning Bolt" (LB) model provides a comprehensive framework for accommodating the effects of habit persistence, unobserved heterogeneity, and state dependence on household brand choice behavior. This paper presents a discrete, dynamic brand-choice model that belongs to the LB class of models. We propose a method for incorporating the effects of variety seeking into the LB model formulation. The proposed formulation explicitly links brand choice and purchase timing behavior via the effe...

  12. Experimental Study on Mechanical Characteristics of Cracked Rock Mass Reinforced by Bolting and Grouting

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The stress hardening characteristics of the reinforced rock mass in uniaxial compression tests were revealed by means of the experimental study on mechanical characteristics of cracked rock mass reinforced by bolting and grouting. And the load-bearing mechanism of the reinforced rock mass was perfectly reflected by the experiment. The results can offer some useful advice for support design and stability analysis of deep drifts in unstable strata.

  13. Assessment of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest in veal calves.

    Science.gov (United States)

    Bartz, B; Collins, M; Stoddard, G; Appleton, A; Livingood, R; Sobcynski, H; Vogel, K D

    2015-09-01

    The purpose of this study was to evaluate the impact of nonpenetrating captive bolt stunning followed by electrical induction of cardiac arrest on veal calf welfare, veal quality, and blood yield. Ninety calves from the same farm were randomly assigned to 1 of 2 treatment groups in a balanced unpaired comparison design. The first treatment group (the "head-only" method-application of the pneumatic nonpenetrating stun to the frontal plate of the skull at the intersection of 2 imaginary lines extending from the lateral canthus to the opposite poll [CONTROL]) was stunned with a nonpenetrating captive bolt gun ( = 45). The second group ( = 45) was stunned with a nonpenetrating captive bolt gun followed by secondary electrical induction of cardiac arrest (the "head/heart" method-initial application of the pneumatic nonpenetrating captive bolt stun followed by 1 s application of an electrical stun to the ventral region of the ribcage directly caudal to the junction of the humerus and scapula while the stunned calf was in lateral recumbence [HEAD/HEART]). Stunning efficacy was the indicator of animal welfare used in this study. All calves were instantly rendered insensible by the initial stun and did not display common indicators of return to consciousness. For meat quality evaluation, all samples were collected from the 12th rib region of the longissimus thoracis. Meat samples were evaluated for color, drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The L* values (measure of meat color lightness) were darker ( 0.05) observed in a* (redness) and b* (yellowness) values between treatments. No differences ( > 0.05) were observed in drip loss, ultimate pH, cook loss, and Warner-Bratzler shear force. The blood yield from the CONTROL group (7,217.9 ± 143.5 g) was greater ( veal calves. PMID:26440354

  14. Joint purpose?

    DEFF Research Database (Denmark)

    Pristed Nielsen, Helene

    2013-01-01

    Starting from Crenshaw´s point that antiracism often fails to interrogate patriarchy and that feminism often reproduces racist practices (1991: 1252), this paper asks: What are the theoretical reasons for believing that feminism and anti-racism can be regarded as fighting for the joint purpose of...

  15. Joint imaging

    International Nuclear Information System (INIS)

    Joint imaging is a proven diagnostic procedure which has become indispensable to the detection and treatment of different joint diseases in almost all disciplines. The method is suited for early diagnosis of joint affections both in soft tissue and bone which cannot be detected by X-ray or other procedures. The local activity accumulation depends on the rate of metabolism and is visualized in the scan, which in turn enables the extension and floridity of focal lesions to be evaluated and followed-up. Although joint scans may often give hints to probabilities relevant to differential diagnosis, the method is non-specific and only useful if based on the underlying clinical picture and X-ray finding, if possible. The radiation exposure is very low and does not represent a hazard in cases of adequate assessment of indication. In pregnant women and children the assessment of indication has to be based on very strict principles. The method is suited for out-patient diagnosis and can be applied in all installations equipped with a gamma camera and a technetium generator. (orig.)

  16. Roof strata horizontal movement assessed by instrumented bolts monitoring and FEM modelling

    Energy Technology Data Exchange (ETDEWEB)

    Pytel, W. [CBPM ' ' Cuprum' ' OBR (Poland)

    2004-07-01

    Results of investigation concerning in-situ assessment of roof strata 3-d movement in the vicinity of a selected hard rock yielding pillar are presented in the paper. Based on laboratory calibration tests it was possible to establish the analytical relationships between the load (or stress) increment within the bolt rod, and the extensometer read-out box increment for all pairs of extensometers, glued-in at five measurement horizons. These relationships were a base for the assessment of rod axial forces and bending moments in time domain. The finite difference method technique was used for bolt rod deflection (lateral) assessment based on the elastic beam (rod) deflection differential equation solution involving the values of in-situ measurement based bending moments. In-situ obtained measurement data were supplemented with numerical experiments performed in a large geometric scale. The numerical models based on the 3-d finite element method, represented the roof bolting-pillar-floor systems in the in-situ measurement sites conditions.

  17. Holographic description of Kerr-Bolt-AdS-dS Spacetimes

    CERN Document Server

    Chen, B; Kamali, V; Setare, M R

    2010-01-01

    We show that there exists a holographic 2D CFT description of a Kerr-Bolt-AdS-dS spacetime. We first consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt-AdS-dS spacetimes and find in the "near region", the wave equation in extremal limit could be written in terms of the $SL(2,R)$ quadratic Casimir. This suggests that there exist dual CFT descriptions of these black holes. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction. Furthermore we study the holographic description of the generic four dimensional non-extremal Kerr-Bolt-AdS-dS black holes. We find that if focusing on the near-horizon region, for the massless scalar scattering in the low-frequency limit, the radial equation could still be rewritten as the $SL(2,R)$ quadratic Casimir, suggesting the existence of dual 2D description. We read the temperatures of the dual CFT from the conformal coordinates and obtain the cent...

  18. Characterization of tensile and shear loading on indented PC-strand cable bolts

    Institute of Scientific and Technical Information of China (English)

    Tadolini Stephen C.; ⇑; Derycke Steven; Bhagwat Anand

    2016-01-01

    The tensile and shear strength of intrinsic bolting support systems has always been a major concern of designers. A comprehensive laboratory testing program was designed to evaluate the tensile and shear strength of individual wires and completely wound PC-strand cables. PC-strand cables with smooth wires and the recent anchorage enhancement innovation of indentation were evaluated and compared. The testing protocol detailed in ISO Standard 15630 utilizes a mandrel system that was investigated at 3 different diameters which alters the wire to mandrel ratio from 2:1 to 9:1. The results demonstrate that the difference between smooth and indented wires is statistically insignificant when larger diameter mandrels are used, and that indentation does not adversely affect strand properties and performance. Insight into the shearing mechanism and evaluation techniques are discussed with the introduction of triaxial loading to describe the PC-strand tensile and shearing mechanisms. Another important result indicates that the shear strength of PC-strand cable bolting systems has a greater shear strength value than traditional steel bar bolting systems.

  19. Holographic description of Kerr-Bolt-AdS-dS spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, B., E-mail: bchen01@pku.edu.c [Department of Physics, and State Key Laboratory of Nuclear Physics and Technology, and Center for High Energy Physics, Peking University, Beijing 100871 (China); Ghezelbash, A.M., E-mail: masoud.ghezelbash@usask.c [Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Kamali, V., E-mail: vkamali1362@gmail.co [Department of Campus of Bijar, Kurdistan University, Bijar (Iran, Islamic Republic of); Setare, M.R., E-mail: rezakord@ipm.i [Department of Campus of Bijar, Kurdistan University, Bijar (Iran, Islamic Republic of)

    2011-07-01

    We show that there exists a holographic 2D CFT description of a Kerr-Bolt-AdS-dS spacetime. We first consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt-AdS-dS spacetimes and find in the 'near region', the wave equation in extremal limit could be written in terms of the SL(2,R) quadratic Casimir. This suggests that there exist dual CFT descriptions of these black holes. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction. Furthermore we study the holographic description of the generic four-dimensional non-extremal Kerr-Bolt-AdS-dS black holes. We find that if focusing on the near-horizon region, for the massless scalar scattering in the low-frequency limit, the radial equation could still be rewritten as the SL(2,R) quadratic Casimir, suggesting the existence of dual 2D description. We read the temperatures of the dual CFT from the conformal coordinates and obtain the central charges by studying the near-horizon geometry of near-extremal black holes. We recover the macroscopic entropy from the microscopic counting. We also show that for the super-radiant scattering, the retarded Green's functions and the corresponding absorption cross sections are in perfect match with CFT prediction.

  20. Developing a highly reliable cae analysis model of the mechanisms that cause bolt loosening in automobiles

    Directory of Open Access Journals (Sweden)

    Ken Hashimoto

    2014-10-01

    Full Text Available In this study, we developed a highly reliable CAE analysis model of the mechanisms that cause loosening of bolt fasteners, which has been a bottleneck in automobile development and design, using a technical element model for highly accurate CAE that we had previously developed, and verified its validity. Specifically, drawing on knowledge gained from our clarification of the mechanisms that cause loosening of bolt fasteners using actual machine tests, we conducted an accelerated bench test consisting of a threedimensional vibration load test of the loosening of bolt fasteners used in mounts and rear suspension arms, where interviews with personnel at an automaker indicated loosening was most pronounced, and reproduced actual machine tests with CAE analysis based on a technical element model for highly accurate CAE analysis. Based on these results, we were able to reproduce dynamic behavior in which larger screw pitches (lead angles lead to greater non-uniformity of surface pressure, particularly around the nut seating surface, causing loosening to occur in areas with the lowest surface pressure. Furthermore, we implemented highly accurate CAE analysis with no error (gap compared to actual machine tests.

  1. A three-dimensional nonlinear reduced-order predictive joint model

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Mechanical joints can have significant effects on the dynamics of assembled structures. However, the lack of efficacious predictive dynamic models for joints hinders accurate prediction of their dynamic behavior. The goal of our work is to develop physics-based, reduced-order, finite element models that are capable of replicating the effects of joints on vibrating structures. The authors recently developed the so-called two-dimensional adjusted Iwan beam element (2-D AIBE) to simulate the hysteretic behavior of bolted joints in 2-D beam structures. In this paper, 2-D AIBE is extended to three-dimensional cases by formulating a three-dimensional adjusted Iwan beam element (3-D AIBE). Impulsive loading experiments are applied to a jointed frame structure and a beam structure containing the same joint. The frame is subjected to excitation out of plane so that the joint is under rotation and single axis bending. By assuming that the rotation in the joint is linear elastic, the parameters of the joint associated with bending in the frame are identified from acceleration responses of the jointed beam structure, using a multi-layer feed-forward neural network (MLFF). Numerical simulation is then performed on the frame structure using the identified parameters. The good agreement between the simulated and experimental impulsive acceleration responses of the frame structure validates the efficacy of the presented 3-D AIBE, and indicates that the model can potentially be applied to more complex structural systems with joint parameters identified from a relatively simple structure.

  2. 煤矿锚杆支护技术现状与展望%On research status and prospect of mine bolt support technique and theory

    Institute of Scientific and Technical Information of China (English)

    朱雷; 周游

    2011-01-01

    The paper introduced the research status of mine bolt support technique and theory,summarized the design methods of bolt support and prospected the bolt support technique and theory.%介绍了锚杆技术及锚杆支护理论的研究现状,总结了锚杆支护的设计方法,提出了发展锚杆支护技术理论所需要开展的内容。

  3. Testing of nuclear grade lubricants and their effects on A540 B24 and A193 B7 bolting materials

    International Nuclear Information System (INIS)

    An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanical properties of common bolting materials; that MoS2 can hydrolyze to form H2S at 1000C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H2O at 2800C in notched tensile tests

  4. Identification of QTLs Related to Bolting in Brassica rapa ssp. pekinensis(syn. Brassica campestris ssp. pekinensis)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-wei; XIE Cong-hua; WANG Xiao-wu; WU Jian; ZHAO Jian-jun; SONG Xiao-fei; LI Ying; ZHANG Yan-guo; XU Dong-hui; SUN Ri-fei; YUAN Yu-xiang

    2006-01-01

    A genetic linkage map of Brassica rapa ssp. pekinensis was constructed with 186 AFLP (amplified fragment length polymorphism) markers by using a doubled-haploid (DH) population with 183 individuals. The individuals were derived from F1 which was developed by crossing a bolting resistant DH line Y-177-12 and an easy bolting DH line Y195-93a.AFLPs were generated by the use of restriction enzymes EcoR Ⅰ and Mse Ⅰ. The segregation of each marker and linkage was analyzed by using JoinMap version 3.0. Mapped markers were aligned in ten linkage groups which covered 887.8 cM with an average marker interval of 4.47 cM. Markers showing skewed segregation ratio were clustered in six LGs.Quantitative trait loci (QTL) were mapped for bolting resistance by using MAPQTL 4.0 package. Four QTLs explaining from 7.0 to 9.4% of the total variation were detected, all of them increase bolting resistance. These mapped QTLs could be used to develop a marker assisted selection programme for bolting resistance breeding.

  5. The nuts and bolts of proofs an introduction to mathematical proofs

    CERN Document Server

    Cupillari, Antonella

    2005-01-01

    The Nuts and Bolts of Proof instructs students on the basic logic of mathematical proofs, showing how and why proofs of mathematical statements work. It provides them with techniques they can use to gain an inside view of the subject, reach other results, remember results more easily, or rederive them if the results are forgotten.A flow chart graphically demonstrates the basic steps in the construction of any proof and numerous examples illustrate the method and detail necessary to prove various kinds of theorems.* The "List of Symbols" has been extended.* Set Theory section has been strengthened with more examples and exercises.* Addition of "A Collection of Proofs"

  6. A prediction model of IASCC initiation stress for bolts in PWR core internals

    Energy Technology Data Exchange (ETDEWEB)

    Fukuya, Koji, E-mail: fukuya@inss.co.j [Institute of Nuclear Safety System, 64 Sata, Mihama, Mikata, Fukui 919-1205 (Japan); Fujii, Katsuhiko; Nishioka, Hiromasa [Institute of Nuclear Safety System, 64 Sata, Mihama, Mikata, Fukui 919-1205 (Japan); Takakura, Kenichi; Nakata, Kiyotomo [Japan Nuclear Energy Safety Organization, 3-17-1 Toranomon, Minato, Tokyo 105-0001 (Japan)

    2010-03-15

    A model of IASCC initiation stress for bolts of core internals in pressurized water reactors was developed considering differences in material property changes due to irradiation and material conditions. Assuming that IASCC initiation was controlled by grain boundary composition and yield strength, these values for each specimen of post-irradiation IASCC initiation tests were calculated by physical kinetic models considering dose rate, temperature, material composition and surface hardening. Then, correlations of grain boundary composition and yield strength with IASCC initiation stress were determined. The model predicted that the IASCC initiation stress became lower with dose and was lower for higher temperature, lower flux and higher surface hardening level.

  7. Tests and analysis of mechanical behaviours of rock bolt components for China's coal mine roadways

    OpenAIRE

    Hongpu Kang; Jinghe Yang; Xianzhi Meng

    2015-01-01

    A series of laboratory tests were performed to study the mechanical behaviours of newly developed high strength rock bolt components, including rebar, thread, plate, and domed washer. The characteristics of deformation and damage of each component were presented. The stress distribution of plate and domed washer was investigated through finite element modelling. The numerical results show that the yield and tensile strengths of the developed high strength rebar are 33.6%–58.3% and 17.2%–28.7%...

  8. The Nuts and Bolts of Proofs An Introduction to Mathematical Proofs

    CERN Document Server

    Cupillari, Antonella

    2011-01-01

    The Nuts and Bolts of Proofs instructs students on the primary basic logic of mathematical proofs, showing how proofs of mathematical statements work. The text provides basic core techniques of how to read and write proofs through examples. The basic mechanics of proofs are provided for a methodical approach in gaining an understanding of the fundamentals to help students reach different results. A variety of fundamental proofs demonstrate the basic steps in the construction of a proof and numerous examples illustrate the method and detail necessary to prove various kinds of theorems. Jumps r

  9. New bolting structure of fractured roof based on the Bossinesq equations

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Present support theories contain a number of shortcomings in the designation of fractured roof bolt parameters of rectangular or trapezoidal coal roadways.Roof fall accidents occur easily in this kind of roadway.Based on the Bossinesq equations and the Mohr strength theory,we propose a theory of an anchored cluster structure for fractured roofs and have investigated the formation of such an anchored cluster structure,its self stability mechanism and mechanical properties.The results show that an anchor and ...

  10. Traducción de elementos culturales en A man for all seasons, de Robert Bolt

    OpenAIRE

    Currás Móstoles, María Rosa

    2010-01-01

    Esta tesis doctoral se centra en el estudio del tratamiento de los referentes culturales en A Man for All Seasons, de Robert Bolt. Partiendo del hecho de que los textos literarios son productos de la cultura que los alojan, una obra literaria manifiesta su adscripción a dicha cultura por medio de ciertos elementos conocidos como referentes culturales. La importancia de los elementos culturales en traducción viene reforzada por la consideración de que los estudios de traducción actualmen...

  11. Use of the cylindrically guided wave technique for the inspection of stud bolts, valve stems and pump shafts

    International Nuclear Information System (INIS)

    Over the last several years, nuclear power plants have expressed concern about failures of bolting, valve stems, and pump shafts. This paper reports on the development of an ultrasonic technique to inspect these components. The authors have successfully demonstrated the cylindrically guided wave technique (CGWT) on a wide range of stud bolts. The CGWT employs zero-degree longitudinal waves constrained to travel within the boundary of the cylindrically shaped components during inspection. Theoretically explained, mode conversion occurs because the ultrasonic wave is guided down the length of the component. These mode-converted signals are dependent upon the diameter of the component under inspection and the longitudinal- and shear-wave velocities of the component material. This technique has also been successfully used on valve stems in the field. The geometry of the valve stem is very similar to that of the stud bolt

  12. Upon bolting the GTR1 and GTR2 transporters mediate transport of glucosinolates to the inflorescence rather than roots

    DEFF Research Database (Denmark)

    Andersen, Tonni Grube; Halkier, Barbara Ann

    2014-01-01

    We recently described the glucosinolate transporters GTR1 and GTR2 as actively contributing to the establishment of tissue-specific distribution of the defense compounds glucosinolates in vegetative Arabidopsis plants. Upon bolting and thereby development of the inflorescence and initiation of seed...... setting, the spatial distribution of glucosinolates does undergo major changes. Here we investigate the role of GTR1 and GTR2 in establishment of glucosinolate source-sink relationships in bolting plants. By in vivo feeding the exogenous p-hydroxybenzylglucosinolate to a rosette leaf or the roots of...... wildtype and a gtr1 gtr2 mutant, we show that this glucosinolate can specifically translocate from the rosette and the roots to the inflorescence in a GTR1- and GTR2-dependent manner. This marks that, upon bolting, the inflorescence rather than the roots constitute the strongest sink for leaf...

  13. SEALING PERFORMANCE OF GASKETED FLANGE JOINTS – A PARAMETRIC STUDY

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2014-12-01

    Full Text Available ABSTRACT: This paper aims at finding the leak rate through ANSI class#150 flange joints using compressed asbestos sheet gasket under combined structural and thermal transient loading conditions. The solution is obtained using two different leak rate models and two different bolt up values. The gasket compressive strain based model employs strains that are determined using finite element analysis. The other model is based on the porous media theory in which gasket is considered as porous media. Leak rates determined using these leak rate models are compared for different tightness classes and discussed. ABSTRAK: Kajian bertujuan mencari kadar bocor menerusi sambungan bebibir kelas ANSI#150 menggunakan gasket kepingan asbestos termampat di bawah kondisi bebanan gabungan struktur dan terma fana. Solusinya diperolehi dengan menggunakan dua model kadar bocor yang berbeza dan dua nilai atas bolt yang berlainan. Model terikan berasaskan pemampat gasket menggunakan terikan yang ditentukan dengan analisis unsur terhingga. Model yang lainnya berasaskan teori bahantara berongga di mana gasket digunakan sebagai medium. Kadar bocor ditentukan dengan menggunakan model kadar bocor, yang kemudiannya dibandingkan pada kelas keketatan yang berbeza dan keputusannya dibincangkan.KEYWORDS: bolted flange; gasket; leak rate; finite element analysis; tightness class compressive strains; porous media Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

  14. Development of ultrasonic testing technique for anchor bolts. Part 2. Development of nondestructive examination method for fatigue cracks by ultrasonic phased array technology

    International Nuclear Information System (INIS)

    Cracks may initiate in anchor bolts in nuclear power plants due to a severe earthquake. Moreover, number of fatigue cracks have been found in the anchor bolts in aged nuclear and thermal power plants. Ultrasonic phased array technology is effective to detect such cracks, and a method is proposed to determine crack depth by using refection echo at the vicinity of crack according to simulation results of wave propagation within bolts. However, detectability of crack and applicability of this method for crack sizing are not known though they are essential to evaluation of crack in bolts by ultrasonic phased array technology. In this report, we prepared M24 and M30 bolt specimens with various slits and fatigue cracks introduced. Three linear array probes with respective frequency of 2, 5 and 10 MHz are used to measure these specimens. The investigation of fracture surface is also performed after finishing all measurements. Measurement results show the following: (1) the frequency of 10 MHz is more appropriate than frequencies of 5 and 2 MHz for detecting crack in bolts; (2) it is easy to detect 1-mm-deep cracks; and (3) it is possible to determine crack depth for M30 bolts with the deviation of 2 mm from actual depth by proposed method, but difficult for M24 bolts. (author)

  15. Discussion on Wind Turbine Bolt Connection Design%风力发电机组高强螺栓连接设计的探讨

    Institute of Scientific and Technical Information of China (English)

    刘洪海; 于春来

    2012-01-01

    本文根据风力发电机组运行特点,从多个角度介绍了风力发电机组高强螺栓连接设计时需要注意的问题.介绍了风力发电机组中高强螺栓连接类型、螺栓连接类型的选择、改善螺栓受力的措施、拧入机体螺栓最小拧入深度的确定、螺栓连接防松方法的选择.通过风电实例,对螺栓连接设计进行了探讨,对风电机组设计有借鉴和启发意义.%Based on the operational features of the wind turbine, wind turbine bolt connection design was presented from multiple perspectives. Bolt connection types, how to properly choose the type of bolt connection, measures to improve the bolt force, screwed into the determination of the minimum depth of the body bolts, bolted locking method selection were presented. By the wind turbine bolt connection design instance, bolt connection design was discussed, which had reference and inspiration to wind turbine design.

  16. Behaviour of high stretch bolts in tension working as part of elements of steel structures, and their tendency to delayed fracturing

    Directory of Open Access Journals (Sweden)

    Moyseychik Evgeniy Alekseevich

    2014-12-01

    Full Text Available In the article, the author has proven that manufacturing and installation errors, as well as contact deformations of high strength bolts, if analyzed as part of tensile connections of steel structures, work in eccentric tension. In pursuance of the effective state standards, the analysis of these bolts is based on the axial tension. The author has analyzed the failure of a steel structure, caused by the fracture of eccentrically loaded bolts made of steel grade XC 42 (France, or C40 (Germany, that later followed the delayed fracturing pattern. The author provides the findings of the lab tests, whereby the above bolts were tested in the presence of an angle washer. The author has also analyzed the findings of low-temperature tests of bolts in tension. The author demonstrates that the strength of high strength bolts is driven by the material, the structure shape, and the thermal treatment pattern. Eccentric tension tests of bolts have proven that cracks emerge in the areas of maximal concentration of stresses (holes in shafts, etc. that coincide with the areas where fibers are in tension; cracks tend to follow the delayed fracturing pattern, and their development is accompanied by the deformation-induced metal heating in the fracture area. Therefore, the analysis of high strength bolts shall concentrate on the eccentric tension with account for contact-induced loads, while the tendency to delayed fracturing may be adjusted through the employment of both metallurgical and process techniques.

  17. Test and application of hydraulic expansion bolts in a roadway under goaf with ultra-close separation

    Institute of Scientific and Technical Information of China (English)

    Wang Xiangyu; Bai Jianbiao; Guo Guanlong; Yu Yang

    2014-01-01

    The roof of a roadway under goaf with ultra-close separation consists of thin rock strata and rocks caving in upper goaf. Influenced by the mining of the upper coal seam, the roof is loose and broken, and its integ-rity is poor. Resin anchored bolts cannot provide an effective anchoring force in such roof conditions. By conducting free expansion tests and field pull-out tests on a hydraulic expansion bolt, this study has ana-lyzed the influencing factors and laws of radial expansion and anchoring force changes in the rod body. This has revealed the anchoring mechanism of such bolts, and has obtained reasonable water injection pressures and suitable drilling diameters (which are 20–25 MPa and 32–35 mm respectively) for the hydraulic expansion bolt (u28 mm) used in these tests. Based on pull-out tests at different interlayer spacing, the applicability of hydraulic expansion bolts had been verified for controlling the roof of road-ways under goaf with ultra-close distance. Combined with the deformation and failure characteristics of the test roadway roof, this paper proposes a united roof-control technology based on the use of hydraulic expansion bolts and advancing intubation for the roof. Engineering practice indicated that the roof of the test roadway did not generate leaking and caving phenomenon, and the amount of roof deformation was controlled to within 150 mm. Maintenance of the roadway roof has been improved significantly, which ensures safe mining in coal seams with ultra-close separation.

  18. STATISTICAL ENTROPIES OF THE TAUB-NUT/BOLT AdS SPACES FROM THE HORIZON CONFORMAL FIELD THEORY

    Institute of Scientific and Technical Information of China (English)

    JING JI-LIANG; ZHOU SAN-QING; HUANG YI-BIN

    2001-01-01

    The covariant phase technique is used to compute the constraint algebra of the four-dimensional space-times which are asymptotic to anti-de Sitter (AdS), such as the planar Taub-NUT AdS and Taub-bolt AdS spaces, and the hyperbolic Taub-bolt AdS space. The standard Virasoro subalgebrae with corresponding central charges for these objects are constructed and the resulting densities of states yield the expected Bekenstein-Hawking entropies.

  19. The Extended Thermodynamic Properties of a topological Taub-NUT/Bolt-AdS spaces

    CERN Document Server

    Lee, Chong Oh

    2015-01-01

    We consider the extended thermodynamic quantities of higher dimensional topological Taub-NUT/Bolt-AdS black holes with a cosmological constant treated as a pressure and find their general form for arbitrary dimensions and the thermodynamics of these configurations is argued to some extent. In particular by introducing Gibbs free energy, it is found out to be a new thermodynamically stable region of these black holes. At an equilibrium condition we find an entropy of a NUT solution, volume, and latent heat are negative where the Clapeyron equation is satisfied for these thermodynamic quantities. These negative volume and entropy may be interpreted as that the environment applies work to the system in the process of the Taub-NUT-AdS black hole formation, and such negative latent heat may indicate a net release of latent energy back into the environment because of evaporating of the system. Intriguingly, we also find that like the AdS black hole case, Taub-Bolt-AdS black hole with two phases (phase of small and ...

  20. A real-time visual inspection method of fastening bolts in freight car operation

    Science.gov (United States)

    Nan, Guo; Yao, JunEn

    2015-10-01

    A real-time inspection of the key components is necessary for ensuring safe operation of freight car. While traditional inspection depends on the trained human inspectors, which is time-consuming and lower efficient. With the development of machine vision, vision-based inspection methods get more railway on-spot applications. The cross rod end fastening bolts are important components on both sides of the train body that fixing locking plates together with the freight car main structure. In our experiment, we get the images containing fastening bolt components, and accurately locate the locking plate position using a linear Support Vector Machine (SVM) locating model trained with Histograms of Oriented Gradients (HOG) features. Then we extract the straight line segment using the Line Segment Detector (LSD) and encoding them in a range, which constitute a straight line segment dataset. Lastly we determine the locking plate's working state by the linear pattern. The experiment result shows that the localization accurate rate is over 99%, the fault detection rate is over 95%, and the module implementation time is 2f/s. The overall performance can completely meet the practical railway safety assurance application.

  1. Development of elastomeric isolators to reduce roof bolting machine drilling noise

    Science.gov (United States)

    Michael, Robert; Yantek, David; Johnson, David; Ferro, Ernie; Swope, Chad

    2015-01-01

    Among underground coal miners, hearing loss remains one of the most common occupational illnesses. In response to this problem, the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) conducts research to reduce the noise emission of underground coal-mining equipment, an example of which is a roof bolting machine. Field studies show that, on average, drilling noise is the most significant contributor to a roof bolting machine operator’s noise exposure. NIOSH OMSHR has determined that the drill steel and chuck are the dominant sources of drilling noise. NIOSH OMSHR, Corry Rubber Corporation, and Kennametal, Inc. have developed a bit isolator that breaks the steel-to-steel link between the drill bit and drill steel and a chuck isolator that breaks the mechanical connection between the drill steel and the chuck, thus reducing the noise radiated by the drill steel and chuck, and the noise exposure of the roof bolter operator. This paper documents the evolution of the bit isolator and chuck isolator including various alternative designs which may enhance performance. Laboratory testing confirms that production bit and chuck isolators reduce the A-weighted sound level generated during drilling by 3.7 to 6.6 dB. Finally, this paper summarizes results of a finite element analysis used to explore the key parameters of the drill bit isolator and chuck isolator to understand the impact these parameters have on noise. PMID:26568650

  2. A Noble Approach of Process Automation in Galvanized Nut, Bolt Manufacturing Industry

    Directory of Open Access Journals (Sweden)

    Akash Samanta

    2012-05-01

    Full Text Available Corrosion costs money”, The Columbus battle institute estimates that corrosion costs Americans more than $ 220 billion annually, about 4.3% of the gross natural product [1].Now a days due to increase of pollution, the rate of corrosion is also increasing day-by-day mainly in India, so, to save the steel structures, galvanizing is the best and the simplest solution. Due to this reason galvanizing industries are increasing day-by-day since mid of 1700s.Galvanizing is a controlled metallurgical combination of zinc and steel that can provide a corrosion resistance in a wide variety of environment. In fact, the galvanized metal corrosion resistance factor can be some 70 to 80 times greater that the base metal material. Keeping in mind the importance of this industry, a noble approach of process automation in galvanized nut-bolt  manufacturing plant is presented here as nuts and bolts are the prime ingredient of any structure. In this paper the main objectives of any industry like survival, profit maximization, profit satisfying and sales growth are fulfilled. Furthermore the environmental aspects i.e. pollution control and energy saving are also considered in this paper. The whole automation process is done using programmable logic controller (PLC which has number of unique advantages like being faster, reliable, requires less maintenance and reprogrammable. The whole system has been designed and tested using GE, FANUC PLC.

  3. Design and demonstration of Bolt Retractor Separation system for X-38 Deorbit Propulsion Stage

    Science.gov (United States)

    Ahmed, R.; Johnston, A. S.; Garrison, J. C.; Gaines, J. L.; Waggoner, J. D.

    2003-09-01

    A separation system was designed for the X-38 experimental crew return vehicle program to allow the Deorbit Propulsion Stage (DPS) to separate from the X-38 lifting body during reentry operations. The configuration chosen was a spring-loaded plunger, known as the Bolt Retractor Subsystem (BRS), that retracts each of the six DPS-to-lifting body attachment bolts across the interface plane after being triggered by a separation nut mechanism. The system was designed to function on the ground in an atmospheric environment as well as in space. The BRS provides the same functionality as that of a completely pyrotechnic shear separation system that would normally be considered ideal for this application, but at a much lower cost. This system also could potentially be applied to future space station crew return vehicles. The design goal of 40 ms retraction time was successfully met in a series of demonstrations performed at the NASA Marshall Space Flight Center's Pyrotechnic Shock Facility (PSF) and Flight Robotics Laboratory (FRL). It must be emphasized that a full-scale test series was not performed on the BRS due to program schedule and cost constraints.

  4. Entry roof truss-bolt system test under the gob of contiguous seams

    Institute of Scientific and Technical Information of China (English)

    LIAN Chuan-jie; XU Wei-ya; WANG Ya-jie

    2007-01-01

    Roof bolt support system has been widely applied in the No.7.9 seam in Caozhuang coal mine.However,it has not been able to be applied in the NO.10-2 seam since the small interburden(2m)between NO.9 and NO.10-2 seam.The NO.9 and NO.10-2 seams are contiguous seams.The NO.9 seam has been mined out and the NO.10-2 seam will be mined under the gob of the NO.9 seam.The roof strata of the NO.10-2 seam may have been weakened and fractured due to the shear failure caused by the NO.9 seam mining activities.The steel beam sets spaced at 0.8 m have been used to support the entry of the NO.10-2 seam.In order to speed up the advance rate and cut entry development cost,a test area,using roof bolt in conjunction with truss-system,was successfully conducted.This paper presents the support system design,application of designed system,and the test results.Test results provide a cheaper,quicker,and safer way to support entry for the No.10-2 seam.

  5. Noise trauma induced by a mousetrap--sound pressure level measurement of vole captive bolt devices.

    Science.gov (United States)

    Frank, Matthias; Napp, Matthias; Lange, Joern; Grossjohann, Rico; Ekkernkamp, Axel; Beule, Achim G

    2010-05-01

    While ballistic parameters of vole captive bolt devices have been reported, there is no investigation on their hazardous potential to cause noise trauma. The aim of this experimental study was to measure the sound pressure levels of vole captive bolt devices. Two different shooting devices were examined with a modular precision sound level meter on an outdoor firing range. Measurements were taken in a semi-circular configuration with measuring points 0 degrees in front of the muzzle, 90 degrees at right angle of the muzzle, and 180 degrees behind the shooting device. Distances between muzzle and microphone were 0.5, 1, 2, 10, and 20 m. Sound pressure levels exceeded 130 dB(C) at any measuring point within the 20-m area. Highest measurements (more than 172 dB[C]) were taken in the 0 degrees direction at the 0.5-m distance for both shooting devices proving the hazardous potential of these gadgets to cause noise trauma. PMID:20345785

  6. Bolt Pull-Out Tests of Anchorage Body under Different Loading Rates

    Directory of Open Access Journals (Sweden)

    Tong-bin Zhao

    2015-01-01

    Full Text Available Based on the force analysis and mechanical transmission mechanism of grouting bolts, the self-developed test apparatus for interfacial mechanics is used to study the distribution rule of axial force and interfacial stress of bolts in anchorage body. At the same time, pull-out tests of anchorage body are simulated with the particle flow code software PFC2D, and stress distribution and failure patters are researched under different loading rates. The results show that the distribution of axial force and interfacial shear stress is nonuniform along the anchorage section: axial force decreases, shear force increases first and then decreases, and the maximum value of both of them is closed to the pull-out side; with the increase of loading rates, both of axial force and interfacial shear stress show a trend of increase in the upper anchorage section but changes are not obvious in the lower anchorage section, which causes serious stress concentration; failure strength of pull-out and loading rates show a linear correlation; according to loading rates’ impact on the anchoring effect, the loading rates’ scope can be divided into soft scope (v100 mm/s.

  7. Professor Usain Bolt Welcomes You to the Schoolyard: Physics for Champions

    Science.gov (United States)

    Vourlias, Kostas; Seroglou, Fanny

    2016-01-01

    Could Usain Bolt achieve what teachers often fail to do? Could this famous Olympic winner challenge and motivate students to study mechanics and introduce them to the principles of physics in a fun way, outside of the classroom? In order to answer these questions, we "invited" for one semester the world record holder to visit our Greek high school in Thessaloniki as a guest teacher. For 13 weeks, 27 fifteen-year-olds run (or at least try to run) side by side with this great athlete, intending to learn his secrets. Within 9.58 s or 100 m, students have the chance to study a "phenomenon" of their daily lives and be introduced to a variety of concepts of physics in a pleasant and effective way. Students use simple athletic and innovative biomechanical equipment for their experiments, but mostly their own bodies, as experimental tools in order to study and to "feel" physics. Students have the chance to compare their athletic abilities to Bolt's and confront some of their ideas concerning concepts of physics.

  8. Mechanical mechanism and support design analysis on bolt-beam-net support in soft rock roadway in Qigou Coal Mine

    Institute of Scientific and Technical Information of China (English)

    LI Tao; SHAN Ren-liang; HAN Huan-shang; YANG Wei-hong; LIU Nian

    2012-01-01

    The deformation and failure mechanical mechanism in soft rock roadway is related to the stability of supported tunnels,which is important to coal mine production and construction.By physical mechanics experiments and X-ray diffraction (XRD) tests,the engineering mechanical properties of soft rock,as well as main mineral composition of the surrounding soft rock of Qigou Coal Mine,were obtained.Based on analysis results,a method using bolt-beam-net combination to support was put forward.Mechanical analysis of the support form was done by using the calculation software FLAC3D.Results show that clay minerals of this mine are kaolinite and illite mixed layer,of which the water absorption is relatively obvious and presented mudding characteristic after absorbing water,with the plasticity index of 0.35,with small expansibility,which is weakly consolidated colloid with strong connected force in unit cell.The rock blocks have the characteristics of moisture absorption softening,and the deformation mechanical mechanism of which is with the coexistence of molecular expansive mechanism,colloid expansive mechanism,and weak layer trend type.The calculation results show that the bolt-beam-net support structure makes the bolt,beam,and roof deform compatibly.The beams make the force in the bolt relatively homogeneous,which restricts the displacement of the tunnel roof as well.Finally,using in situ monitoring,the numerical results were verified.

  9. The characteristics of head wounds inflicted by "humane killer" (captive-bolt gun)--a 15-year study.

    Science.gov (United States)

    Simic, Milan; Draskovic, Dragan; Stojiljkovic, Goran; Vukovic, Radenko; Budimlija, Zoran M

    2007-09-01

    The "humane killer" or captive-bolt gun, is the tool/weapon widely used in meat industry and private farmer households for slaughtering animal stock. Out of 17,250 autopsies performed at the Institute of Forensic Medicine in Novi Sad during the 15-year period (1991-2005), 29 cases of suicides and two homicides were committed by captive-bolt pistols. Wounds inflicted by captive-bolt guns have specific morphological features, distinctive from wounds made by other kinds of hand firearms. Selected features of the captive-bolt wounds (punched round entrance and a double pattern of smoke soiling) depend on distance and angle of instrument at the time of firing. Autopsy findings were compared with an experimental model consisting of 20 domestic pigs. Obtained results confirmed that the appearance of the entrance hole and soot deposits, along with differences in shape, location, extent, and density of soot blackening, could be useful in identification of weapon, direction of discharge, shooting distance, and angle of the muzzle to the frontal and sagittal planes of the head at the moment of fire. PMID:17767661

  10. Reliability of Tubular Joints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    In this paper the preliminary results obtained by tests on tubular joints are presented. The joints are T-joints and the loading is static. It is the intention in continuation of these tests to perform tests on other types of joints (e.g. Y-joints) and also with dynamic loading. The purpose...... of the test is partly to obtain empirical data for the ultimate load-carrying capacity of tubular T-joints and partly to obtain some experience in performing tests with tubular joints. It is well known that tubular joints are usually designed in offshore engineering on the basis of empirical formulas obtained...

  11. Spacesuit mobility knee joints

    Science.gov (United States)

    Vykukal, H. C. (Inventor)

    1979-01-01

    Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  12. Preliminary Design and Analysis of an In-plane PRSEUS Joint

    Science.gov (United States)

    Lovejoy, Andrew E.; Poplawski, Steven

    2013-01-01

    As part of the National Aeronautics and Space Administration's (NASA's) Environmentally Responsible Aviation (ERA) program, the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) has been designed, developed and tested. However, PRSEUS development efforts to date have only addressed joints required to transfer bending moments between PRSEUS panels. Development of in-plane joints for the PRSEUS concept is necessary to facilitate in-plane transfer of load from PRSEUS panels to an adjacent structure, such as from a wing panel into a fuselage. This paper presents preliminary design and analysis of an in-plane PRSEUS joint for connecting PRSEUS panels at the termination of the rod-stiffened stringers. Design requirements are provided, the PRSEUS blade joint concept is presented, and preliminary design changes and analyses are carried out to examine the feasibility of the proposed in-plane PRSEUS blade joint. The study conducted herein focuses mainly on the PRSEUS structure on one side of the joint. In particular, the design requirements for the rod shear stress and bolt bearing stress are examined. A PRSEUS blade joint design was developed that demonstrates the feasibility of this in-plane PRSEUS joint concept to terminate the rod-stiffened stringers. The presented design only demonstrates feasibility, therefore, some areas of refinement are presented that would lead to a more optimum and realistic design.

  13. BOLTS: a BiOphysical Larval Tracking System for Measuring Dispersal Characteristics and Marine Population Connectivity

    Science.gov (United States)

    Paris, C. B.; Srinivasan, A.; Kourafalou, V.; Sponaugle, S.; Cowen, R. K.

    2008-12-01

    While metapopulation research with hypothetical dispersal matrices has shown how the scales of larval dispersal, transport processes, local recruitment, and temporal and spatial variability in dispersal influence population persistence, the pattern of demographic connectivity produced by larval dispersal is still a key uncertainty. To address this problem, a coupled bio-physical model has been developed that quantifies the degree of connectivity between populations. Such spatially explicit models, forced by dynamic currents coupled to a realistic seascape and life history traits, produce dispersal kernels for a range of scales over which dispersal is practically unquantifiable by current empirical methods. The BiOphysical Larval Tracking System (BOLTS) presented here allows a Lagrangian stochastic individual-based model (IBM) to be coupled via OPENDAP framework to any 3-dimensional fields of circulation models including to domains of various resolutions through 'Lagrangian nesting'. We demonstrate the capabilities of the software in measuring the characteristics of dispersal and evaluating the variability of larval connectivity through two examples at different scales: 1) Caribbean-scale simulations of BOLTS using the large scale (resolution ~7 km) Hybrid Coordinate Ocean Model (HYCOM) from the Global Data Assimilative Experiment (GODAE) provide us with expected connectivity patterns of a reef building coral. By seeding the model with a large number of active particles, it is possible to assemble dispersal kernels and migration matrices from the start (spawning) and the end point (settlement) of individual particle trajectories. Any single run is a stochastic realization of a probabilistic process, thus the full probability density function (pdf) of the kernel requires averaging over many dispersal events. The model output is further corroborated with empirical measures of gene flow among coral colonies around the Caribbean. 2) Coastal-scale simulations of BOLTS

  14. Inflatable rock bolt bond strength versus rock mass rating (RMR):A comparative analysis of pull-out testing data from underground mines in Nevada

    Institute of Scientific and Technical Information of China (English)

    Barnard Chase; Kallu Raj R.; Warren Sean; Thareja Rahul

    2016-01-01

    The purpose of this paper is to establish confidence in anticipated minimum bond strength for inflatable rock bolts by comparing the bond strength to variable geotechnical conditions using the rock mass rating (RMR) system. To investigate a correlation between these parameters, the minimum bond strength of pull-out tested inflatable rock bolts was compared to the RMR of the rock in which these bolts were placed. Bond strength vs. RMR plots indicate that expected minimum bond strength is positively corre-lated with RMR;however, the correlation is not strong. Cumulative percent graphs indicate that 97%of pull-out tests result in a minimum bond strength of 3.3 and 1.7 ton/m in RMR P 45 and<45, respectively. Although lower bond strengths are more commonly encountered in low RMR ground, high bond strengths are possible as well, yielding higher variability in bond strengths in low RMR ground. Bond strength of friction bolts relies on contact between the rock bolt and drill hole. Experience in Nevada indicates that RMR is known to affect both the quality and consistency of drill holes which likely affects bond strength. Drilling and bolting in low RMR ground is more sensitive to drilling and bolting practices, and strategies for maximizing bond strength in these conditions are discussed.

  15. Fracture failure analysis of driving bolts%驱动螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    邓德伟; 张翠萍; 鲁俊

    2013-01-01

    Driving bolts made of 3Cr13 stainless steel was fractured during the service .Chemical composition , mechanical properties and microstructure of the failed bolt were analysed .The results show that the inappropriate heat treatment leads anormal microstructure to unquenched and untempered which result to the bolt failure .The microstructure is tempered martensites and undissolved carbides that lead to high microhardness .Additionally , globular nonmetallic inclusions and multidirectional cracks are also observed in the bolt and accelerated the failure when the bolt is suffered from a shock or a torsional load .%3 Cr13不锈钢驱动螺栓在服役一段时间后在螺纹处发生断裂,对其化学成分、力学性能、断口及显微组织进行观察和分析。结果表明,螺栓断裂主要是由于热处理工艺不当,导致螺栓最终服役状态并非调质态,显微组织为回火马氏体及未溶碳化物颗粒,螺栓整体硬度过高;另外,组织中存在链状及球状非金属夹杂物,螺纹部位也有多种取向的裂纹,因而螺栓在受到冲击或扭转载荷时,裂纹和非金属夹杂可能成为裂纹源,以致发生脆性断裂。

  16. INFORMATION FOR USERS OF NUTS, BOLTS, SCREWS, NAILS AND RIVETS (SCEM GROUP 47)

    CERN Multimedia

    Logistics Group

    2002-01-01

    We should like to remind users that, since the closure of the self-service stores, nuts, bolts, screws, nails and rivets (Group 47 of the Stores Catalogue) can be obtained, in smaller packages than via EDH, from the 'Emergency Counter' in the Central Stores (Building 73, R-002) upon presentation of a duly completed hard-copy Materials Request form. The 'Emergency Counter' is open Mondays to Fridays from 7.30 a.m. to 11.50 a.m. and from 1.00 p.m. to 4.20 p.m. Information concerning the available packages can be found under the appropriate SCEM reference number in the Stores Catalogue. Logistics Group SPL Division

  17. 1300 MPa High Strength Steel for Bolt with Superior Delayed Fracture Resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By the increase in Mo content, the addition of microalloying elements V and Nb and by reducing the contents of Mn, P and S based on the composition of steel 42CrMo, we have developed a 1300 MPa-grade high strength steel (ADF1) for bolts. The sustained load bending test, sustained load tensile test and stress corrosion cracking test have been carried out to evaluate the delayed fracture resistance of steel ADF1 and commercial steel 42CrMo. The results showed that steel ADF1 has superior delayed fracture resistance to that of 42CrMo steel. It's concluded that the superior delayed fracture resistance of ADF1 is mainly due to the increase of tempering temperature, fine homogeneously distributed MC carbide and fine prior austenite grain size.

  18. Resolution of Generic Safety Issue 29: Bolting degradation or failure in nuclear power plants

    International Nuclear Information System (INIS)

    This report describes the US Nuclear Regulatory Commission's (NRC's) Generic Safety Issue 29, ''Bolting Degradation or Failure in Nuclear Power Plants,'' including the bases for establishing the issue and its historical highlights. The report also describes the activities of the Atomic Industrial Forum (AIF) relevant to this issue, including its cooperation with the Materials Properties Council (MPC) to organize a task group to help resolve the issue. The Electric Power Research Institute, supported by the AIF/MPC task group, prepared and issued a two-volume document that provides, in part, the technical basis for resolving Generic Safety Issue 29. This report presents the NRC's review and evaluation of the two-volume document and NRC's conclusion that this document, in conjunction with other information from both industry and NRC, provides the bases for resolving this issue

  19. Extraction of Bolt Supporting Role%浅议锚杆支护技术

    Institute of Scientific and Technical Information of China (English)

    刁先锋

    2015-01-01

    In recent years, with the continuous development of coal mining technology, mining depth increase gradually. Mines and roadway support is an important guarantee of coal mine safety production. At present,which has been widely applied bolting. This article from the category,anchor supporting form,function and matters needing attention aspects in this paper,the personal views.%近几年来,随着煤矿开采技术的不断发展,开采深度逐步增加。矿井和巷道支护是煤矿安全生产的重要保证。目前,锚杆支护应用较为广泛。从锚杆类别、支护形式、作用、注意事项等方面阐述个人观点。

  20. Crystalline capsules: metal-organic frameworks locked by size-matching ligand bolts.

    Science.gov (United States)

    Wang, Hao; Xu, Jian; Zhang, Da-Shuai; Chen, Qiang; Wen, Rong-Mei; Chang, Ze; Bu, Xian-He

    2015-05-11

    Metal-organic frameworks (MOFs) are shown to be good examples of a new class of crystalline porous materials for guest encapsulation. Since the encapsulation/release of guest molecules in MOF hosts is a reversible process in nature, how to prevent the leaching of guests from the open pores with minimal and nondestructive modifications of the structure is a critical issue. To address this issue, we herein propose a novel strategy of encapsulating guests by introducing size-matching organic ligands as bolts to lock the pores of the MOFs through deliberately anchoring onto the open metal sites in the pores. Our proposed strategy provides a mechanical way to prevent the leaching of guests and thereby has less dependence on the specific chemical environment of the hosts, thus making it applicable for a wide variety of existing MOFs once the size-matching ligands are employed.

  1. Numerical study of rock bolting parameter variation effect on stability of stratified, composite roof structure of drift in a coal mine

    Institute of Scientific and Technical Information of China (English)

    LU Ting-kan; LIU Yu-zhou

    2005-01-01

    Described the outcomes of a comprehensive numerical modeling on the rock bolting performance for preventing the deformation of stratified, composite roof structure of drift in a coal mine. The investigation was undertaken in the adverse geological conditions, with variation of belt parameters, including length, density, distribution, pretension,as well as the geometry of opening, so as to determine the effect of bolting parameter variation on roof deformation and stability. The outcomes clearly demonstrated that a significant improvement of roof stability can be achieved associating with bolting parameters optimization, and indicated the importance of flexible geotechnical designation of rock mbolting reinforcement in mining practice.

  2. 上海中心大厦巨型框架关键节点设计研究%Research on key joints design of mega frame of the Shanghai Tower

    Institute of Scientific and Technical Information of China (English)

    丁洁民; 李久鹏; 何志军

    2011-01-01

    The Shanghai Tower adopts the lateral resisting system of mega frame-core-outrigger structure. Joints design is the key phase during design procedure of the mega frame. Firstly, the principles of the performance-based design of joints were introduced briefly. Secondly, the design of two typical joint of the mega frame, the joint of outrigger to super-column and the long bolt joint of the belt truss, were checked. The joint of outrigger to super-column bears bending moment and axial force, the stress state of which was very complicated. The reasonableness of simplified formula was verified by using finite element analysis. The results show that the simplified formula meets the project requirements and can be accepted as a check formula in the preliminary design. The long bolt joint of the belt truss which has a super-long length includes a large quantity of bolts, thick splice plates and thick member sections. According to finite element analysis, the performance and mechanical behavior of the joint are revealed and its reliability is verified too. The results show that the bolt joint has enough capacity under specific performance requirements. Terminal bolts transfer more force and intermediate bolts transfer little. With the increasing of loads, the nonhomogeneity of transfer force of bolts reduces. The mechanical property of members will be changed as the bolt joint has large length.%上海中心大厦主体结构采用巨型框架-伸臂-核心筒结构体系,节点设计是巨型框架设计中的关键环节.介绍了基于性能的节点设计原则,研究了伸臂桁架与巨型柱连接节点、环带桁架螺栓拼接节点两类典型节点.伸臂桁架与巨型柱连接节点,节点区受力复杂,同时承受较大的轴力与弯矩,运用有限元方法对该类节点简化设计公式的适用性进行了验证.研究表明:简化设计公式能够满足工程精度要求,可作为该类节点初步估算的验算公式;环带桁架螺栓节点具有

  3. International joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2001-01-01

    The article analysis problems connected with corporate joint ventures. Among others the possible conflicts between the joint venture agreement and the statutes of the companies is examined, as well as certain problems connected to the fact that the joint venture partners have created commen control...... over their joint company....

  4. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  5. Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt.

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon-bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon-bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon-bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon-bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  6. Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Zhi-Yu Wang

    2016-08-01

    Full Text Available Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details.

  7. Ultrasonic Detection of Small Crack in Studs[Bolts] by Time Difference of Thread Signals(TDTS)

    International Nuclear Information System (INIS)

    It is difficult to detect such flaws as stress - corrosion cracking or corrosion wastage(loss of bolt diameter) in the threads. In many cases the critical size of a flaw is very small(1-2 mm order). This paper describes how it is possible to discriminate small flaw indications in threads using the time difference or thread signals(TDTS) by a signal-conditioning technique

  8. 飞轮连接螺栓可靠性提升研究%Reliability Improvement Of Flywheel Connecting Bolt

    Institute of Scientific and Technical Information of China (English)

    栗明; 胡伟; 李广; 赵建永

    2016-01-01

    The flywheel and crankshaft is connected with the bolt of the flywheel,As flywheel connecting boltsis an important part of the transmission torque.If there is a problem of the flywheel connecting bolt fracture,is a great harm,it will cause the crank and the connecting parts to be declared worthless,cause serious economic losses. In order to ensure the reliability of the bolt connection,the following file will through the working condition、the influence of the EVB、driver’s driving habits、clutch matching specification、the bolts design to put forward corrective and preventive measures.%飞轮与曲轴采用飞轮连接螺栓进行联接,由于飞轮连接螺栓是传递力矩的重要部件,如果出现飞轮连接螺栓断裂的问题,危害性极大,会导致曲轴和曲轴连接件报废,造成严重的经济损失;为了确保螺栓联接的可靠性,文章从使用的工况、 EVB排气制动使用对发动机影响情况、用户驾驶习惯、离合器匹配规范、曲轴飞轮连接螺栓设计等方面提出整改预防措施。

  9. Cortisol Hormone Concentration and Meat Quality of Beef Cattle Stunned by Captive Bolt Stun Gun before Slaughtering

    OpenAIRE

    K. Maghfiroh; H. Latif; K. Santoso

    2014-01-01

    This study was aimed to describe cortisol hormone concentration and meat quality which were produced in beef cattle stunned with captive bolt stun gun before slaughtering. Blood and meat samples were taken from Brahman cross steers (n= 11) in two abattoirs located in West Java and Banten. Blood samples were collected immediately after slaughtering. Cortisol hormone concentration in the serum was measured by using radioimmunoassay (RIA). The descriptive, correlation, and regression analyses we...

  10. Review of "System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal

    OpenAIRE

    McSharry Patrick E

    2007-01-01

    Abstract "System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal introduces the relevant concepts, terminology, and techniques of this field of science. It emphasises the modelling and computational challenges of taking a multidisciplinary approach to biology. This book provides a comprehensive introduction to systems biology and will form a valuable resource for students, teachers and researchers from both experimental and theoretical discipli...

  11. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series To use the sharing features ... 4 out of 4 Normal anatomy Overview The knee is a complex joint. It contains the distal ...

  12. Shoulder Joint Replacement

    Science.gov (United States)

    ... en because of implant loosening, wear, infection, and dislocation. When this occurs, a second joint replacement surgery — called a revision surgery — may be necessary. Is Shoulder Joint Replacement for You? The decision to have ...

  13. Culture - joint fluid

    Science.gov (United States)

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  14. Tunneling by Mining Method:Lecture III:Anchor Bolts%漫谈矿山法隧道技术第三讲--锚杆

    Institute of Scientific and Technical Information of China (English)

    关宝树

    2016-01-01

    分析我国隧道锚杆支护技术中存在的主要问题,包括:1)没有实现商品化;2)多采用注浆式锚杆,没有针对不同的围岩条件采用不同的锚杆;3)不设垫板的锚杆比比皆是;4)锚杆功能单一;5)锚杆施工管理不到位。针对这些问题:1)重申了锚杆的功能;2)认为要实现锚杆的商品化,首先要求锚杆规格标准化,生产工厂化,介绍了英国的《锚杆技术标准》,指出我国也应着手编写《锚杆行业标准》,以利于锚杆商品化的实现,或者以一条新铁路线或以企业为试点设置锚杆制备厂;3)着重介绍了提高锚杆支护功能的措施———提高附着刚性和剪切刚性、提高锚固材料的充填饱满度、强化锚杆施工管理;4)介绍了几种新型锚杆的构造、规格、功能、优点、适用条件等,包括摩擦式锚杆(ZAM膨胀型锚杆、高承载力摩擦式锚杆、具有排水效果和注浆功能的锚杆)和纤维锚杆;5)介绍了发光型简易锚杆轴力计,并将其与通常的轴力量测进行对比,结果大致吻合。最后指出,锚杆的首要问题是加快工厂化(商业化)进程,编制了行业标准;提高锚杆支护效果要在锚固材料和围岩2方面下功夫;针对性地加强对摩擦式锚杆的研究及锚杆充填率评价方法的研究也应提到日程上来。%In this paper,the major limitations of application of anchor bolt to tunnel in China are analyzed,which mainly include:1)Non-industrialization of anchor bolt.2)Merely using grouting anchor bolt regardless of other types. 3)Gasket is not applied for anchor bolt.4)The anchor bolt function is simple.5 )Poor anchor bolt construction management system.In order to address these problems,the following issues are discussed:1)The anchor bolt function should be fully re-assessed.2)The anchor bolt should be standardized and the manufacturing of the anchor bolt should be

  15. 3-D Analysis of Flanged Joints Through Various Preload Methods Using ANSYS

    Science.gov (United States)

    Murugan, Jeyaraj Paul; Kurian, Thomas; Jayaprakash, Janardhan; Sreedharapanickar, Somanath

    2015-10-01

    Flanged joints are being employed in aerospace solid rocket motor hardware for the integration of various systems or subsystems. Hence, the design of flanged joints is very important in ensuring the integrity of motor while functioning. As these joints are subjected to higher loads due to internal pressure acting inside the motor chamber, an appropriate preload is required to be applied in this joint before subjecting it to the external load. Preload, also known as clamp load, is applied on the fastener and helps to hold the mating flanges together. Generally preload is simulated as a thermal load and the exact preload is obtained through number of iterations. Infact, more iterations are required when considering the material nonlinearity of the bolt. This way of simulation will take more computational time for generating the required preload. Now a days most commercial software packages use pretension elements for simulating the preload. This element does not require iterations for inducing the preload and it can be solved with single iteration. This approach takes less computational time and thus one can study the characteristics of the joint easily by varying the preload. When the structure contains more number of joints with different sizes of fasteners, pretension elements can be used compared to thermal load approach for simulating each size of fastener. This paper covers the details of analyses carried out simulating the preload through various options viz., preload through thermal, initial state command and pretension element etc. using ANSYS finite element package.

  16. Asthmagenicity of coal mine roof-bolting resins: an assessment using inhalation provocation tests

    Energy Technology Data Exchange (ETDEWEB)

    Convery, R.; Ward, A.; Ward, R.; Bromly, C.L.; Dennis, J.H.; Stenton, S.C.; Bourke, S.J.; Hendrick, D.J. [University of Newcastle Upon Tyne, Newcastle upon Tyne (United Kingdom). Dept. of Respiratory Medicine

    2001-03-01

    Inhalation provocation tests were used to assess whether the volatile products of an activated resin had caused occupational asthma in a non-random sample of six asthmatic coal miners. The resin system uses the polymerization of polyester and styrene under the influence of the cross-linking agent dibenzoyl peroxide to secure roof, wall and floor bolts in mine tunnels. The tests were conducted sequentially in a double-blind fashion over a 'dose' range which extended just beyond the maximum likely to have been experienced occupationally during a single day's work. The tests were monitored by symptoms, changes in the forced expiratory volume in 1 s (FEV1) and changes in airway responsiveness. All subjects completed the series of tests without any significant decrements in FEV1 or significant increases in airway responsiveness. It was concluded that the use of this resin system is not likely to have been the cause of the asthma in the test subjects, nor in the larger group of miners of which they were a sample, but neither possibility is fully excluded and the participants may not have been adequately representative of other asthmatic coal miners.

  17. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Directory of Open Access Journals (Sweden)

    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  18. Failure Analysis on Fracture of Worm-gear Connecting Bolts%蜗轮连接螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    王荣; 李玲

    2012-01-01

    装卸料机上的蜗轮连接螺栓材料为35钢,强度等级为10.9级,在设备运行大约10a后发生断裂。对断裂螺栓进行宏观、化学成分、硬度、金相、能谱和断口分析后得出,该螺栓的断裂性质为双向弯曲疲劳断裂,螺栓表面的脱碳和螺纹颈部的应力集中降低了该部位的疲劳性能。通过综合分析和螺栓受力估算后得出,螺栓断裂的主要原因是螺栓和内齿轮螺栓孔之间存在较大的间隙,使螺栓的受力状态和受力大小过早地发生了变化,造成连接螺栓疲劳断裂。%The worm-gear connecting bolts of refueling machines of a nuclear power plant,with material of 35 steel and strength grade of 10.9,fractured after the device running for about a decade,and means such as macro examination,chemical compositions analysis,hardness test,metallographic examination,fracture SEM analysis and so on,were used to analyze the fractured bolts.The results show that the fracture property of the bolts is two-way bending fatigue fracture.Surface decarburization of the bolts and stress concentration at the bolt thread neck decreased the fatigue strength,which resulted fatigue cracks formed here.By comprehensive analysis and force estimating,it was concluded that the main reason for the fracture is that there is a big gap between the bolt shank parts and their matching internal gear bolt holes,which made the force state and force size of the bolts changed early and finally resulted in fatigue fracture of the worm-gear connecting bolts.

  19. Design on the Transporting and Bolting Machine with Hopper and Two Arms%料斗式两臂运锚机的研制

    Institute of Scientific and Technical Information of China (English)

    马昭

    2014-01-01

    The transporting and bolting machine with hopper and two arms is a kind of equipment which is researched according to parallel working of the excavating and bolting integration on fully mechanized winning faces. It has the function of bolt supporting, materials transporting and self-driving. Its main structure, operation principle and service condition are introduced. It realizes reasonably connect of excavating, bolting and transporting work. The excavating and bolting efficiency is improved.%料斗式两臂运锚机是基于井下综掘工作面掘锚平行作业而研制的一种可进行锚杆支护和物料转运的具有自行走功能的运锚装备,本文详细介绍了该机的主要结构组成、工作原理以及使用情况,可实现掘锚运作业的合理衔接,提高了成巷效率。

  20. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts

    Science.gov (United States)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  1. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    Science.gov (United States)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  2. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    Science.gov (United States)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests. PMID:27475551

  3. Experimental and Numerical Analysis of the Shear Behaviour of Cemented Concrete-Rock Joints

    Science.gov (United States)

    Tian, H. M.; Chen, W. Z.; Yang, D. S.; Yang, J. P.

    2015-01-01

    The shear behaviour of cemented concrete-rock joints is a key factor affecting the shear resistance of dam foundations, arch bridge foundations, rock socketed piles and rock bolts in rock engineering. This paper presents an experimental and numerical investigation of the shear behaviour of cemented concrete-rock joints by direct shear tests. In this study we focused on the bond strength of cemented concrete-rock joints, so limestone with smooth surfaces was used for samples preparation to reduce the roughness effect. The experimental results show that the shear strength of joints with good adhesion is strongly dependent on the bond strength of the cohesive interfaces when the applied normal stress is less than 6 MPa. In addition, the sudden and gradual bond failure processes of the cohesive interfaces were observed with an increase of the normal stress. A simple, yet realistic, model of cemented concrete-rock joint is proposed to simulate the observed behaviour, including elastic behaviour of the bond before peak shear stress and post-peak behaviour due to bond failure and friction increase. Finally, the parameters analysis and calibration of the proposed model are presented.

  4. SEALING LARGE-DIAMETER CAST-IRON PIPE JOINTS UNDER LIVE CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kiran M. Kothari; Gerard T. Pittard

    2005-07-01

    Utilities in the U.S. operate over 75,000 km (47,000 miles) of old cast-iron pipes for gas distribution. Bell-and-spigot joints that connect pipe sections together tend to leak as these pipes age. Current repair practices are costly and highly disruptive. The objective of this program is to design, test and commercialize a robotic system capable of sealing multiple castiron bell and spigot joints from a single pipe entry point. The proposed system will perform repairs with the pipe in service by traveling through the pipe, cleaning each joint surface, and installing a stainless-steel sleeve lined with an epoxy-impregnated felt across the joint. This approach will save considerable time and labor, minimize excavation, avoid traffic disruption, and eliminate any requirement to interrupt service to customers (which would result in enormous expense to utilities). Technical challenges include: (1) repair sleeves must compensate for diametric variation and eccentricity of old cast-iron pipes; (2) the assembly must travel long distances through pipes containing debris; (3) the pipe wall must be effectively cleaned in the immediate area of the joint to assure good bonding of the sleeve; and (4) an innovative bolt-on entry fitting is required to conduct safe repair operations on live mains.

  5. Jointly Poisson processes

    CERN Document Server

    Johnson, D H

    2009-01-01

    What constitutes jointly Poisson processes remains an unresolved issue. This report reviews the current state of the theory and indicates how the accepted but unproven model equals that resulting from the small time-interval limit of jointly Bernoulli processes. One intriguing consequence of these models is that jointly Poisson processes can only be positively correlated as measured by the correlation coefficient defined by cumulants of the probability generating functional.

  6. Regulation of bolting and identification of the α-tubulin gene family in Brassica rapa L. ssp pekinensis.

    Science.gov (United States)

    Zhang, Y W; Jin, D; Xu, C; Zhang, L; Guo, M H; Fang, Z Y

    2016-01-01

    Microtubules are important components of eukaryotic cells, and they play vital roles in cell morphogenesis, carrying of signaling molecules, transport of materials, and establishing the cell polarity. During bolting of biennial plants, cell division and elongation are involved, and cell elongation inevitably involves the microtubules arrangement and expression of related genes. So we deduce that it is of great significance to figure out the mechanism of bolting and flowering in which TUA genes are involved. In the present study, bioinformatic methods were used to predict and identify the α-tubulin gene family (BrTUAs) in Brassica rapa L. ssp pekinensis (Chinese cabbage) through the alignment of AtTUA gene sequence from Arabidopsis thaliana with the B. rapa genome database (http://brassicadb.org/brad/) using the basic local alignment search tool. The change in the structure and functions of BrTUAs during the process of evolution, cis-acting elements in the promoter sequences of BrTUAs, and the expression of the identified genes was also analyzed. Twelve members of the α-tubulin gene family were identified from Chinese cabbage. The gene length, intron, exon, and promoter regions were determined to have changed significantly during the genome evolution. Only five of the 12 members were encoded completely and were observed to differ in their spatial and temporal expression. The five BrTUA promoter sequences contained different numbers of cis-elements responsive to light and low-temperature response, cis-elements responsive among which hormonal responses were significantly different. We also report that the BrTUAs were involved in the regulation of the bolting in Chinese cabbage, and propose that this process could be controlled by regulating the expression of BrTUAs. PMID:26909938

  7. Discussion on Bolt Load of Lens Gasket Seal%透镜垫密封螺栓载荷的探讨

    Institute of Scientific and Technical Information of China (English)

    刘国振; 杨晓雨; 刘利云; 张建秀

    2015-01-01

    讨论了HG/T 20582—2011中透镜垫密封的螺栓载荷,并采用有限元方法对透镜垫螺栓载荷进行了分析,指出了螺栓载荷计算公式中存在的一些问题,并提出了新的计算公式,以供工程设计参考。%The bolt load of lens gasket seal in HG/T 20582—201 1 was discussed,and the bolt load was analyzed by the finite element method.Some problems on the calculated formula of the bolt load were pointed out.The new formula was presented for engineering design reference.

  8. Ultrasonic testing of core baffle former bolts of the core tanks of pressurised water reactors; Ultraschallpruefung von Kernumfassungsschrauben der Kernbehaelter von Druckwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Bies, Christian M.; Alaerts, Louis; Bonitz, Frank W. [Westinghouse Electric Germany GmbH, Mannheim (Germany); Devlin, Russell S.; Minogue, Patrick [WesDyne International, Madison, PA (United States)

    2013-07-01

    This article presents the MIDAS VI testing robot used by Westinghouse / WesDyne. This is a remotely operated underwater vehicle which positions ultrasonic probes under camera control. This vehicle makes it possible to substantially reduce the time required for setting up and preparing ultrasonic tests on core baffle former bolts. It has also accelerated the test procedure itself. Test methods have also been developed for bolt types which were hitherto considered incapable of being tested. One of these methods is based on a phased array probe. The article also reports on experiences gained over the course of years in testing core baffle former bolts in European nuclear power plants using the SUPREEM testing robot.

  9. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and re- view of the literature

    Directory of Open Access Journals (Sweden)

    Aggerwal Sameer

    2011-06-01

    Full Text Available 【Abstract】Breakage of locking bolts is an impor- tant cause of interlocking nail failure in femoral fractures. It usually occurs in the form of single breakage in one of the distal bolts of the nail or nail breakage around the distal locking hole. Here we report an unusual case of intramedul- lary femoral nail failure with segmental breakage of both the distal locking bolts. Such a scenario usually complicates further management. We successfully managed this case with exchange nailing without bone grafting. Here we briefly reviewed the literature regarding such an unusual presenta- tion and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation. Key words: Femoral fractures; Bone screws; Frac- ture fixation, intramedullary; Fracture healing

  10. Mechanics of Sheeting Joints

    Science.gov (United States)

    Martel, S. J.

    2015-12-01

    Physical breakdown of rock across a broad scale spectrum involves fracturing. In many areas large fractures develop near the topographic surface, with sheeting joints being among the most impressive. Sheeting joints share many geometric, textural, and kinematic features with other joints (opening-mode fractures) but differ in that they are (a) discernibly curved, (b) open near the topographic surface, and (c) form subparallel to the topographic surface. Where sheeting joints are geologically young, the surface-parallel compressive stresses are typically several MPa or greater. Sheeting joints are best developed beneath domes, ridges, and saddles; they also are reported, albeit rarely, beneath valleys or bowls. A mechanism that accounts for all these associations has been sought for more than a century: neither erosion of overburden nor high lateral compressive stresses alone suffices. Sheeting joints are not accounted for by Mohr-Coulomb shear failure criteria. Principles of linear elastic fracture mechanics, together with the mechanical effect of a curved topographic surface, do provide a basis for understanding sheeting joint growth and the pattern sheeting joints form. Compressive stresses parallel to a singly or doubly convex topographic surface induce a tensile stress perpendicular to the surface at shallow depths; in some cases this alone could overcome the weight of overburden to open sheeting joints. If regional horizontal compressive stresses, augmented by thermal stresses, are an order of magnitude or so greater than a characteristic vertical stress that scales with topographic amplitude, then topographic stress perturbations can cause sheeting joints to open near the top of a ridge. This topographic effect can be augmented by pressure within sheeting joints arising from water, ice, or salt. Water pressure could be particularly important in helping drive sheeting joints downslope beneath valleys. Once sheeting joints have formed, the rock sheets between

  11. Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.)

    Institute of Scientific and Technical Information of China (English)

    Gui-xiao LA; Ping FANG; Yi-bo TENG; Ya-juan LI; Xian-yong LIN

    2009-01-01

    The effects of CO2 enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassioa alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height,stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem,11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L,elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios.Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition.

  12. Managing Joint Production Motivation

    DEFF Research Database (Denmark)

    Lindenberg, Siegwart; Foss, Nicolai Juul

    2011-01-01

    representations of actions and tasks; cognitively coordinate cooperation; and choose their own behaviors in terms of joint goals. Using goal-framing theory, we explain how motivation for joint production can be managed by cognitive/symbolic management and organizational design....

  13. JET Joint Undertaking

    International Nuclear Information System (INIS)

    The paper presents the progress report of the Joint European Torus (JET) Joint Undertaking, 1986. The report contains a survey of the scientific and technical achievements on JET during 1986; the more important articles referred to in this survey are reproduced as appendices to this Report. The last section discusses developments which might improve the overall performance of the machine. (U.K.)

  14. Creep of timber joints

    NARCIS (Netherlands)

    Van de Kuilen, J.W.G.

    2008-01-01

    A creep analysis has been performed on nailed, toothed-plates and split-ring joints in a varying uncontrolled climate. The load levels varied between 30% and 50% of the average ultimate short term strength of these joints, tested in accordance with ISO 6891. The climate in which the tests were perfo

  15. KEY TECHNIQUE TO COMPOSITELY SUPPORTING THE ROADWAY DRIVEN ALONG PREVIOUS GOAF WITH BOLTS,BARS AND CHAIN MESHES UNDER COMPLEX CONDTTIONS

    Institute of Scientific and Technical Information of China (English)

    HOUChaojiong; HEYanan; ZHANGYidong; GUANXuemao

    1995-01-01

    Large cross sectional roadways driven along the previous goaf are always in fragmental surrounding rocks, and remarkably deform under the influence of mining disturbance. It can successfully be supported by the composite bolt-bar-chain mesh support. However, success can only be achieved by getting hold of the key techniques as follows: rationally determining the size of the goaf-side rib, adopting bolts with extendible rod, determining rational parameters and strengthening the integral structure of the supporting system. These have proved effective and profitable by the practice at Dongpang colliery, Xingtai Coal Mining Administration. Hebei province,and are now in application there.

  16. Strategies for joint appointments.

    Science.gov (United States)

    Royle, J; Crooks, D L

    1985-01-01

    The structure and policies governing joint appointments discussed above, are developed primarily through cooperation and collaboration between nursing service and education institutions. The joint appointee participates in the process of negotiation of salary, benefits and role responsibilities and exploration of the implications of the appointment for personal career development. Implementation and maintenance of the appointment requires the collaborative efforts of the joint appointee with both contracting agencies. Factors influencing the functioning of joint appointees have been identified and strategies to facilitate functioning presented. The joint appointee must be independent in thought and action yet adaptable to work within the boundaries of two social systems with differing values and expectations. Nursing management, peers and students can provide the support needed to overcome the frustrations and to achieve the rewards inherent in successful implementation of an exciting and innovative role. PMID:3852805

  17. Experimental study on using expansion bolt anchoring half pipe to reinforce beam negative moment area%膨胀螺栓外锚半钢管加固梁负弯矩区的试验研究

    Institute of Scientific and Technical Information of China (English)

    王智巍; 张鸿梅; 周静雅

    2013-01-01

    The test used the implant expansion bolt anchor half pipe technology to achieve carbon fiber reinforced frame beam negative moment area of purpose. Providing a new reinforcement technology that uses half pipe to anchor CFRP at the negative moment of the beam position for node reinforcement. To verify the efficiency of the strengthening methods, five frame joints have been tested under static loading test and analyzed with the ANSYS non-linear finite element analysis software. The test and analysis results show that by the strengthening way of this paper the ultimate load of the five specimens are increased.%试验采用内植膨胀螺栓外锚半钢管技术来达到碳纤维布加固框架节点梁负弯矩区的目的.提出利用半钢管对负弯矩区加固的碳纤维布进行锚固的一种新技术.通过对5个框架节点的静力加载试验,以及用非线性软件ANSYS进行模拟分析,验证了本文采用的加固方法可行.试验及分析结果表明,本文采用的加固方法加固效果明显,能有效提高试件的承载力.

  18. Cylindrically guided wave technique for detection of stress corrosion cracking and corrosion wastage in long stud-bolts

    International Nuclear Information System (INIS)

    The authors discuss how, when performing an ultrasonic inspection of a cylindrical body, the sound waves, or pulses, will interact with the boundaries of the cylinder and produce mode-converted as well as normal longitudinal waves. The elastic energy of the wave propagating along the length of the cylinder is concentrated and produces strong echoes from shallow defects in the specimen. In threaded specimens, the guided wave produces signals from the threads that can be differentiated from defects in the cylinder. This paper reports on a study using the guided wave theory conducted to determine the optimum inspection transducer size and frequency relative to stud-bolt diameter and length. Bolts ranging from 25 to 285 cm (10 to 112 in.) in length and 2.5 to 11.5 cm (1 to 4.5 in.) in diameter were tested. For all cases, theoretical predictions agreed well with the experimental data. In this paper, the theory, experimental apparatus, and testing results are discussed

  19. Cortisol Hormone Concentration and Meat Quality of Beef Cattle Stunned by Captive Bolt Stun Gun before Slaughtering

    Directory of Open Access Journals (Sweden)

    K. Maghfiroh

    2014-12-01

    Full Text Available This study was aimed to describe cortisol hormone concentration and meat quality which were produced in beef cattle stunned with captive bolt stun gun before slaughtering. Blood and meat samples were taken from Brahman cross steers (n= 11 in two abattoirs located in West Java and Banten. Blood samples were collected immediately after slaughtering. Cortisol hormone concentration in the serum was measured by using radioimmunoassay (RIA. The descriptive, correlation, and regression analyses were used to interprete data. Meat quality assessment was based on pH, cooking loss, and complete drainage of blood. The average of cortisol hormone concentration was 26.59 ng/mL. Meat pH at 1 h postmortem and 24 h postmortem were 6.65 and 6.21, respectively. Meat cooking loss was 26.77%. Blood drainage in meat samples of each cattle showed complete drainage. There was a significant correlation (P<0.05 between cortisol concentrations and pH at 1 hour postmortem as well as cortisol concentration and cooking loss. There was no significant correlation between pH at 24 h postmortem and cooking loss. Cattle was stunned with a captive bolt stun gun before slaughtering produced meat with complete blood drainage but had high cortisol hormone concentration and pH ultimate.

  20. Structural health monitoring for bolt loosening via a non-invasive vibro-haptics human-machine cooperative interface

    Science.gov (United States)

    Pekedis, Mahmut; Mascerañas, David; Turan, Gursoy; Ercan, Emre; Farrar, Charles R.; Yildiz, Hasan

    2015-08-01

    For the last two decades, developments in damage detection algorithms have greatly increased the potential for autonomous decisions about structural health. However, we are still struggling to build autonomous tools that can match the ability of a human to detect and localize the quantity of damage in structures. Therefore, there is a growing interest in merging the computational and cognitive concepts to improve the solution of structural health monitoring (SHM). The main object of this research is to apply the human-machine cooperative approach on a tower structure to detect damage. The cooperation approach includes haptic tools to create an appropriate collaboration between SHM sensor networks, statistical compression techniques and humans. Damage simulation in the structure is conducted by releasing some of the bolt loads. Accelerometers are bonded to various locations of the tower members to acquire the dynamic response of the structure. The obtained accelerometer results are encoded in three different ways to represent them as a haptic stimulus for the human subjects. Then, the participants are subjected to each of these stimuli to detect the bolt loosened damage in the tower. Results obtained from the human-machine cooperation demonstrate that the human subjects were able to recognize the damage with an accuracy of 88 ± 20.21% and response time of 5.87 ± 2.33 s. As a result, it is concluded that the currently developed human-machine cooperation SHM may provide a useful framework to interact with abstract entities such as data from a sensor network.

  1. Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts.

    Science.gov (United States)

    Schwenk, Barbara K; Lechner, Isabel; Ross, Steffen G; Gascho, Dominic; Kneubuehl, Beat P; Glardon, Matthieu; Stoffel, Michael H

    2016-03-01

    Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0mm (56.0-100.0mm) vs 36.6mm (29.3-44.3mm) and from skin to the thalamus 144.8mm (117.1-172.0mm) vs 102.0 (101.0-121.0mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes. PMID:26610289

  2. 基于ADAMS的枪机碰撞力研究%Bolt's Impact Simulation Based on ADAMS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    In this paper ,the simple model of the barrel and automation was established by ADAMS ,the counter-recoil velocity and the mass of bolt and bolt box were defined by Impact function in ADAMS ,and the accurate control of step size and interpolation algorithm was realized ,then the counter-recoil collision force was obtained .%  建立由枪管和自动机构件组成的简易模型,通过在ADAMS中进行动力学仿真,赋予枪机和枪机框实际的复进到位速度和质量,利用ADAMS中的Impact函数对参数进行设置,并对求解步长和插值算法等进行精确控制,对结果进行测量,得到了枪机复进到位的碰撞力。

  3. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

  4. Hip joint replacement

    Science.gov (United States)

    ... may have problems with infection, loosening, or even dislocation of the new hip joint. Over time the artificial ... Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, ...

  5. Joint Injection/Aspiration

    Science.gov (United States)

    ... Working It Out: Common Techniques for Conflict Resolution Workplace Diversity & Team Performance CME & MOC Understanding MOC ACR's MOC ... infection is suspected, aspirating the joint to gather cultures is ... Communications and Marketing. This patient information is provided for ...

  6. MP Joint Arthritis

    Science.gov (United States)

    ... Therapist? Media Find a Hand Surgeon MP Joint Arthritis Email to a friend * required fields From * To * ... in to name and customize your collection. DESCRIPTION Arthritis is the wearing away of the cartilage at ...

  7. Temporomandibular Joint Disorder

    Science.gov (United States)

    ... 2008 Previous Next Related Articles: Temporomandibular Joint Disorder (TMD) Are You Biting Off More Than You Can Chew? Equilibration May Lessen TMD Pain Fender-benders: Source of TMD? First Comes ...

  8. Healthy Joints Matter

    Science.gov (United States)

    ... dietary supplements, such as green tea and various vitamins, to see if they can keep your joints ... body, such as your ears, nose, and windpipe. Fibromyalgia (fi-bro-my-AL-juh). A condition that ...

  9. Joint Quantum Institute

    Data.gov (United States)

    Federal Laboratory Consortium — The Joint Quantum Institute (JQI) is pursuing that goal through the work of leading quantum scientists from the Department of Physics of the University of Maryland...

  10. Torque ultra difference fault analysis of flywheel bolt tightening machine%飞轮螺栓拧紧机力矩超差问题分析

    Institute of Scientific and Technical Information of China (English)

    李绍红

    2013-01-01

    对轿车发动机主装配线飞轮螺栓拧紧机力矩超差原因进行分析并排除故障.%In this paper, the main assembly line for car engine flywheel bolt tightening machine torque error cause is analyzed, and the troubleshooting process is described.

  11. 一种螺栓拉伸器校准方法研究%A Calibration Method Research for Bolt Tensioners

    Institute of Scientific and Technical Information of China (English)

    赵兴亮; 杨思凡; 李玮; 陈宝有

    2015-01-01

    A calibration method for bolt tensioners is presented. According to the theory of Newton's Third Law, the calibration device is researched and designed to calibrate the bolt tensioners. The meas-urement error and repeatability analysis and uncertainty evaluation show the linearity is good. Considering the measurement error is within ±1%, which meets the calibration requirements for bolt tensioners, the designed calibration device is capable to carry out the calibration work for bolt tensioners.%介绍了螺栓拉伸器的一种校准方法,运用牛顿第三定律的基本原理,研究并设计了一种拉伸器校准装置对螺栓拉伸器进行校准,通过对实验结果的误差和重复性分析,以及不确定度评定,表明该拉伸器校准装置具有良好的线性度,测量误差在±1%以内,符合螺栓拉伸器校准要求,达到了校准螺栓拉伸器的目的,可以开展螺栓拉伸器校准工作。

  12. Joint Venture Contracts

    OpenAIRE

    Pimentel, Dinarco

    2015-01-01

    Joint Venture contracts are contracting models typically designed to reach international markets. In spite of being used at the national level, a joint venture is based on single or multiple contracts between two individuals, two institutions, two organizations or two different entrepreneurial entities joining forces, meeting synergies to reach a common goal.Initially, these types of contracts were justifiable based on the need of different economic agents penetrating the most inaccessible ma...

  13. Joint contingency contracting

    OpenAIRE

    Johnson, Ellsworth K.; Paton, Bryan H.; Threat, Edward W.; Haptonstall, Lisa A.

    2005-01-01

    The purpose of this Master of Business Administration (MBA) Professional Report is to investigate and analyze the means by which Contingency Contracting Officers (CCO) can effectively operate in a Joint contingency environment and to validate the Defense Contract Management Agency's (DCMA) entry and exit criteria for contingency contracting missions. Joint contingencies encompass regional conflicts, humanitarian and peacekeeping missions, and international or domestic disaster relief missions...

  14. High pressure ceramic joint

    Science.gov (United States)

    Ward, Michael E.; Harkins, Bruce D.

    1993-01-01

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  15. The use of hydraulic bolts for coupling in order to shorten the maintenance critical path in turbo generator sites; Uso de tornillos hidraulicos para acoplamiento a fin de acortar la ruta critica del mantenimiento en sitios de turbogeneradores

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Arelle, Carlos [Turbomaquinas S. A. de C.V., La Piedad, Michoacan (Mexico)

    2007-11-15

    The use of hydraulic bolts has permitted to diminish the time in the critical path of the maintenance, attaining to reduce the total costs and avoiding that some bolts are stuck, benefits the on time planning of the maintenance. The bolts of radial adjustment provide significant benefits to the General Turbine operator. The hydraulic bolts avoid the normal problems of the conventional coupling bolts and rapidly help to re-establish the couple concentricity. The bolts are individually designed to meet a specific geometry and are a direct replacement of the conventional bolts. [Spanish] El uso de tornillos hidraulicos ha permitido disminuir el tiempo de la ruta critica del mantenimiento, logrando reducir los costos totales y al evitar que algun tornillo se atore, beneficia la planeacion de mantenimientos a tiempo. Los tornillos de ajuste radial proveen beneficios significativos al operador de la Turbina General. Los tornillos hidraulicos eliminan los problemas normales de los tornillos de acoplamiento convencionales y rapidamente ayudan a restablecer la concentridad del cople. Los tornillos son disenados individualmente para completar una geometria especifica y son un reemplazo directo de los tornillos convencionales.

  16. Failure Analysis of Ruptured Bolts in Coal Gas Heater%煤气加热器断裂螺栓的失效分析

    Institute of Scientific and Technical Information of China (English)

    朱岗; 邱艳丽; 杨振国

    2008-01-01

    对350 MW燃气轮机发电装置煤气加热器盲板上的螺栓断裂的失效机理及其起因进行了系统性的研究. 采用一系列的微宏观表征方法,分析其化学组成、金相结构、宏观外形、微观形态和微区的化学结构. 试验结果表明:螺栓的失效主要是由其材质不良、表面加工不当、紧固力不合理以及腐蚀环境等共同作用造起的. 进一步讨论了螺栓的电偶腐蚀、缝隙腐蚀和应力腐蚀开裂的相关机理,并提出相应的预防措施.%The failure mechanisms and causes of the ruptured bolts of blind plate on a coal gas heater of 350 MW gas turbine generating unit were systematically studied. A series of macroscopic and microscopic analysis methods were used to characterize chemical composition, metallographic structure, macroscopic appearance, microscopic morphology and microarea chemical composition of the bolts. The experimental results showed that the failure of the bolts were mainly caused by galvanic corrosion, crevice corrosion and followed stress corrosion cracking, which were resulted from inferior material, unqualified processing quality, and unsuitable fastening force and corrosive environment. The relevant mechanisms on crevice corrosion and stress corrosion cracking of the bolts were carefully discussed and countermeasures for preventing the bolts were also proposed.

  17. Statistical time series methods for damage diagnosis in a scale aircraft skeleton structure: loosened bolts damage scenarios

    International Nuclear Information System (INIS)

    A comparative assessment of several vibration based statistical time series methods for Structural Health Monitoring (SHM) is presented via their application to a scale aircraft skeleton laboratory structure. A brief overview of the methods, which are either scalar or vector type, non-parametric or parametric, and pertain to either the response-only or excitation-response cases, is provided. Damage diagnosis, including both the detection and identification subproblems, is tackled via scalar or vector vibration signals. The methods' effectiveness is assessed via repeated experiments under various damage scenarios, with each scenario corresponding to the loosening of one or more selected bolts. The results of the study confirm the 'global' damage detection capability and effectiveness of statistical time series methods for SHM.

  18. Depillaring of total thickness of a thick coal seam in single lift using cable bolts:A case study

    Institute of Scientific and Technical Information of China (English)

    Kumar Rakesh; Mishra Arvind Kumar; Singh Arun Kumar; Singh Amit Kumar; Ram Sahendra; Singh Rajendra

    2016-01-01

    Explaining fundamentals of application of cable bolting for a thick seam depillaring, this paper summa-rizes the results of field studies conducted during adoption of this approach in more than fifteen panels of Madhusudanpur 7 pit and incline mine. Nearly 7.0 m thick Kajora top coal seam of this mine is developed on pillars along the floor horizon to an average height of 3.0 m, leaving a coal band of around 4.0 m along the roof. Analysis of procured core samples showed that roof strata are easily caveable with a caveability index value of around 2000 only. Easily caveable overlying strata and shallow depth of cover alleviated most of the expected strata mechanics problems of the thick seam mining. However, extraction of total thickness at shallow cover caused differential-subsidence and cracks on the surface. These manifestations were immediately tackled to avoid creation of a breathing path for spontaneous heating in the extracted area.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-15

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

  20. Statistical time series methods for damage diagnosis in a scale aircraft skeleton structure: loosened bolts damage scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Kopsaftopoulos, Fotis P; Fassois, Spilios D, E-mail: fkopsaf@mech.upatras.gr, E-mail: fassois@mech.upatras.gr [Stochastic Mechanical Systems and Automation (SMSA) Laboratory Department of Mechanical and Aeronautical Engineering University of Patras, GR 265 00 Patras (Greece)

    2011-07-19

    A comparative assessment of several vibration based statistical time series methods for Structural Health Monitoring (SHM) is presented via their application to a scale aircraft skeleton laboratory structure. A brief overview of the methods, which are either scalar or vector type, non-parametric or parametric, and pertain to either the response-only or excitation-response cases, is provided. Damage diagnosis, including both the detection and identification subproblems, is tackled via scalar or vector vibration signals. The methods' effectiveness is assessed via repeated experiments under various damage scenarios, with each scenario corresponding to the loosening of one or more selected bolts. The results of the study confirm the 'global' damage detection capability and effectiveness of statistical time series methods for SHM.

  1. [Biomechanics of the ankle joint].

    Science.gov (United States)

    Zwipp, H

    1989-03-01

    According to Fick, the tree-dimensional patterns of foot motion are best characterized as jawlike movement. Anatomically and biomechanically, this process represents conjoined, synchronous motion within the three mobile segments of the hindfoot: the ankle joint, the posterior subtalar joint, and the anterior subtalar joint. Foot kinematics can be described more completely if the anterior subtalar joint is defined not only as the talocalcaneal navicular joint, but as including the calcaneocuboid joint, thus representing the transverse joint of the tarsus, i.e., the Chopart joint. The axes of these three joints can be defined precisely. In some parts they represent a screwlike motion, clockwise or counter-clockwise, around the central ligamentous structures (fibulotibial ligament, talocalcaneal interosseous ligament, bifurcate ligament). The individual anatomy and structure of these ligaments provide variations in the degree and direction of foot motion. A precise knowledge of foot kinematics is important in surgical ligament and joint reconstruction and in selective foot arthrodeses.

  2. Tests and analysis of mechanical behaviours of rock bolt components for China’s coal mine roadways

    Institute of Scientific and Technical Information of China (English)

    Hongpu Kang; Jinghe Yang; Xianzhi Meng

    2015-01-01

    A series of laboratory tests were performed to study the mechanical behaviours of newly developed high strength rock bolt components, including rebar, thread, plate, and domed washer. The characteristics of deformation and damage of each component were presented. The stress distribution of plate and domed washer was investigated through finite element modelling. The numerical results show that the yield and tensile strengths of the developed high strength rebar are 33.6%e58.3% and 17.2%e28.7% greater than those of the conventional rebar, respectively. The increase in yield strength was higher than that in tensile strength, suggesting an increase in yield to tensile strength ratio and a decrease in elongation. It is well-known that the thread processing may not be of high precision and accuracy as expected, which is characterised as rough thread surface, non-identical tooth height, toe stripping, and cracks in the surface. Hardening during thread processing tends to increase the thread yield and tensile strengths. In this paper, the typical deformation process of arch-shaped plate is classified into five stages. The tested plates exhibited distinct deformation characteristics and bearing capacities due to variations in shape, size, material and presence of washer. It was observed that uneven bottom surface, low bearing arch and large radius of the transitional arc connecting bearing arch and bottom surface were the major reasons ac-counting for low load-bearing capacity of plates. The performance of domed washer has a close relation with the shape, size, strength, and deformation compatibility with plate. Stress concentration was observed on the periphery of the contact surface between domed washer and plate, which is significantly influenced by the strength of domed washer and is considered to be 20%e30%higher than that of plate. Finally, a case study in the Datong coal mining district was presented, and the support pattern and effect of the developed rock bolt

  3. Joint ventures in medical services.

    Science.gov (United States)

    Rublee, D A

    1987-01-01

    This paper is an overview of joint-venture activity in healthcare, describing trends in joint ventures and raising issues for physicians. The purposes are to discuss the major current facets of joint-venture alliances in healthcare and to identify policy issues that arise from the trend to use joint ventures as an organizational tool. Speculation is made about the future role of joint ventures in the organization of healthcare.

  4. Investigation of Residual Stresses and Distortion in Welded Pipe-Flange Joint of Different Classes

    Directory of Open Access Journals (Sweden)

    Muhammad Abid

    2012-10-01

    Full Text Available ABSTRACT: Pipe and flange joints are commonly used in petrochemical, nuclear and process industries. Commonly, welding is used to make these joints which produces residual stresses and distortions. These stresses have detrimental effects on the structural integrity and service performance of the welded pipe joints. The objective of this study is to investigate the residual stresses and distortions during Gas Metal Arc Welding of pipe of schedule 40, nominal diameter 200 mm with different ANSI flanges of class numbers 150, 300, 600, 900, 1500, and 2500. Welding parameters including: voltage, current and heat as inputs were selected based on the literature available. The behaviour of the flanges of different classes is also discussed. In addition, the finite element methodology presented, in this paper, can be helpful for developing welding procedures for a range of pipe flange welded joint sizes in order to control the residual stresses and deformations. This will lead to optimised performance during bolt up and operating conditions.ABSTRAK: Paip dan sambungan flan biasanya digunakan dalam industri petrokimia, nuklear dan proses. Kimpalan menghasilkan tegasan sisa dan herotan, yang memberikan kesan yang merbahaya ke atas integriti struktur dan prestasi servis sambungan kimpalan paip. Objektif kajian ini adalah untuk mengkaji tegasan sisa dan herotan ketika kimpalan arka logam gas paip berjadual 40, diameter nominal 200mm dengan flan ANSI yang berbeza kelas # 150, 300, 600, 900, 1500, dan 2500. Parameter kimpalan termasuklah; voltan, arus dan haba input yang dipilih berdasarkan literatur sediada. Kelakuan flan yang berbeza kelas telah dibincangkan. Kaedah elemen finit yang dibentangkan adalah berguna dalam membangunkan prosedur kimpalan bagi julat saiz kimpalan flan paip unutk mengawal tegasan sisa dan canggaan i.e. bagi mengoptimakan prestasi ketika bolt up dan sedang beroperasi.                                 

  5. The temporomandibular joint

    International Nuclear Information System (INIS)

    Whilst the temporomandibular joint is in many ways unique, it is subject to all the diseases and disorders found in joints in other parts of the human skeleton. By far the most common disorder is injury, followed by arthropathy, acute and chronic dislocations, ankylosis, and in rare instances, neoplasms. The diagnosis and management of the temporomandibular joint are the primary responsibility of the oral surgeon. Nevertheless, this anatomical region is an area in which the cooperation of medical and dental disciplines may be required for the satisfactory conclusion of treatment. The more so when the disease process involves either associated psychosomatic illness or malignancy. The mainstay of the diagnosis is a careful radiological examination of the joint. There exists a delicate relationship between the dentition, the muscles of mastication, and the temporomandibular articulation, which is controlled by arthrokinetic reflex activity of the branches of the 5th cranial nerve. Imbalance between one or more of the components of this integrated system frequently leads to disturbances in function. Pain-dysfunction disorders constitute the larger part of temporomandibular joint disturbances generally encountered

  6. Distal radioulnar joint injuries

    Directory of Open Access Journals (Sweden)

    Binu P Thomas

    2012-01-01

    Full Text Available Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint , forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments.The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis.

  7. Dissimilar metals joint evaluation

    Science.gov (United States)

    Wakefield, M. E.; Apodaca, L. E.

    1974-01-01

    Dissimilar metals tubular joints between 2219-T851 aluminum alloy and 304L stainless steel were fabricated and tested to evaluate bonding processes. Joints were fabricated by four processes: (1) inertia (friction) weldings, where the metals are spun and forced together to create the weld; (2) explosive welding, where the metals are impacted together at high velocity; (3) co-extrusion, where the metals are extruded in contact at high temperature to promote diffusion; and (4) swaging, where residual stresses in the metals after a stretching operation maintain forced contact in mutual shear areas. Fifteen joints of each type were prepared and evaluated in a 6.35 cm (2.50 in.) O.D. size, with 0.32 cm (0.13 in.) wall thickness, and 7.6 cm (3.0 in) total length. The joints were tested to evaluate their ability to withstand pressure cycle, thermal cycle, galvanic corrosion and burst tests. Leakage tests and other non-destructive test techniques were used to evaluate the behavior of the joints, and the microstructure of the bond areas was analyzed.

  8. Periprosthetic Joint Infections

    Directory of Open Access Journals (Sweden)

    Ana Lucia L. Lima

    2013-01-01

    Full Text Available Implantation of joint prostheses is becoming increasingly common, especially for the hip and knee. Infection is considered to be the most devastating of prosthesis-related complications, leading to prolonged hospitalization, repeated surgical intervention, and even definitive loss of the implant. The main risk factors to periprosthetic joint infections (PJIs are advanced age, malnutrition, obesity, diabetes mellitus, HIV infection at an advanced stage, presence of distant infectious foci, and antecedents of arthroscopy or infection in previous arthroplasty. Joint prostheses can become infected through three different routes: direct implantation, hematogenic infection, and reactivation of latent infection. Gram-positive bacteria predominate in cases of PJI, mainly Staphylococcus aureus and Staphylococcus epidermidis. PJIs present characteristic signs that can be divided into acute and chronic manifestations. The main imaging method used in diagnosing joint prosthesis infections is X-ray. Computed tomography (CT scan may assist in distinguishing between septic and aseptic loosening. Three-phase bone scintigraphy using technetium has high sensitivity, but low specificity. Positron emission tomography using fluorodeoxyglucose (FDG-PET presents very divergent results in the literature. Definitive diagnosis of infection should be made by isolating the microorganism through cultures on material obtained from joint fluid puncturing, surgical wound secretions, surgical debridement procedures, or sonication fluid. Success in treating PJI depends on extensive surgical debridement and adequate and effective antibiotic therapy. Treatment in two stages using a spacer is recommended for most chronic infections in arthroplasty cases. Treatment in a single procedure is appropriate in carefully selected cases.

  9. Temporomandibular joint examination reviewed

    Directory of Open Access Journals (Sweden)

    L. Guarda Nardini

    2011-09-01

    Full Text Available The temporo-mandibular joint (TMJ it’s a joint closely related to the skull base, the spine, and the jaws; all these anatomical structures must be taken in consideration when evaluating pain involving the tmj. In order to detect patients affected by pathology or dysfunctions of the tmj, physical examination is of great value in orienting the diagnosis. Inspection must consider the symmetry of the body, the dental status and the type of occlusion. Palpation is a way to assess contractiont involving the muscles of the masticatory system and of the neck. Auscultation, based on articular noise provides means to determine whether we are dealing with degeneration of the joint or a dislocation of the intrarticular disc. In order to confirm the diagnosis obtained with the clinical evaluation, it’s useful to perform imaging techniques as opt, tomography and TC of the tmj and electromyokineosiography – index of the mandibular functionality and of the muscles status. MRI and dynamic MRI are among the non invasive exams which give the greatest amount of information, regarding the disc position and the joint degeneration. Arthroscopy is an invasive technique that allows early diagnosis of degeneration and is helpful to reveal early inflammatory processes of the joint.

  10. Distal radioulnar joint injuries.

    Science.gov (United States)

    Thomas, Binu P; Sreekanth, Raveendran

    2012-09-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  11. 锚杆尾部断裂机制和防破断方法应用%Fracture Mechanism of the Bolt Tail and Applications of Anti-breaking Methods

    Institute of Scientific and Technical Information of China (English)

    李夕兵; 马少维; 马春德; 李金跃; 郭阳

    2013-01-01

    基于岩体弹性能释放对锚杆的冲击作用,采用冲击动力学中刚性块对杆轴向碰撞的应力解,推导出了锚杆断裂的4种围岩应力条件.在此基础上分析了岩石弹性模量、锚杆弹性模量、锚杆直径与岩石泊松比等因素对锚杆断裂的影响.分析结果显示:在这4种围岩应力条件中,杆头被一次冲断基本上是不可能的,由于其他几种锚杆断裂时的围岩应力条件很接近,所以在实际中锚杆尾部被一次冲断的可能性最高,这也印证了锚杆尾部容易断裂的观点;另外,锚杆断裂的围岩应力条件受岩石弹性模量、岩石泊松比、岩石密度、锚杆弹性模量、锚杆密度、锚杆直径等因素的影响,其中影响较大的是岩石弹性模量与锚杆弹性模量的比值、锚杆直径和岩石泊松比;锚杆尾部断裂的围岩应力条件对于改进锚杆形式、优化锚杆力学性质有理论指导意义.最后,以马路坪矿的巷道工程为例,说明了锚杆防破断方法的具体应用,收到了良好的效果,可以在实际工程中推广应用.%Based on the bolt impacted by the elastic energy of rock mass and the stress solution that a rigid block collides with rod along axially in impact dynamics is adopted; four stress conditions of rock mass are derived before the bolt is fractured. And on the basis, several factors, including elastic modulus of rock, elastic modulus of bolt, diameter of bolt, and Poisson's ratio of rock, are discussed. The analytical results show as follows: In four stress conditions of rock mass, it is impossible that bolt head is directly fractured, but the rest parts have high possibility. In addition, the rest bolts have the similar stress conditions of rock mass, therefore it has a high possibility that the bolt tail is directly fractured, it also confirms with the view that bolt tail is easily broken; Besides, before the bolt is fractured, the stress condition of rock mass is affected by

  12. Ground Support Strategies at the Turquoise Ridge Joint Venture, Nevada

    Science.gov (United States)

    Sandbak, L. A.; Rai, A. R.

    2013-05-01

    Weak rock masses of high grade Carlin-trend gold mineralization are encountered in the Turquoise Ridge Joint Venture underground mine. The sediments consist of very weak and altered limestone, mudstone, and carbon-rich clays. The rock mass ratings are described as very poor to poor (Bieniawski in Proceedings of the symposium on exploration for rock engineering, Johannesburg, South Africa, pp. 97-106, 1976). The undercut and fill or boxes stoping mining methods are used because of the low dipping ore body geometry, complex geology, and weak rock mass. Design criteria are chosen to keep openings in weak rock as small as possible to prevent unraveling and to minimize supplementary support. Typical ground support for drifting includes the use of bolts, mesh, spiling, and shotcrete. Quality control of cemented rock fill (CRF) through sampling and aggregate sieve testing is necessary to insure high support strength. Specific support may include shotcrete arches with steel ring sets and CRF "arches" as a replacement of weak rock masses around long-term mine openings. Movement monitoring is utilized in problem areas and is needed to quantify and validate computer modeling.

  13. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications. PMID:26868932

  14. Studies of welded joints

    Directory of Open Access Journals (Sweden)

    J. M. Krupa

    2010-07-01

    Full Text Available Studies of a welded joint were described. The joint was made as a result of the reconstruction of a truss and one of the possible means to make a repair. The studies were of a simulation character and were targeted at the detection of welding defects and imperfections thatshould be eliminated in a real structure. A model was designed and on this model the tests and examinations were carried out. The modelwas made under the same conditions as the conditions adopted for repair. It corresponded to the real object in shape and dimensions, and in the proposed technique of welding and welding parameters. The model was composed of five plates joined together with twelve beads.The destructive and non-destructive tests were carried out; the whole structure and the respective welds were also examined visually. Thedefects and imperfections in welds were detected by surface methods of inspection, penetration tests and magnetic particle flaw detection.The model of the welded joint was prepared by destructive methods, a technique that would never be permitted in the case of a realstructure. For the investigations it was necessary to cut out the specimens from the welded joint in direction transverse to the weld run. The specimens were subjected to metallographic examinations and hardness measurements. Additionally, the joint cross-section was examined by destructive testing methods to enable precise determination of the internal defects and imperfections. The surface methods were applied again, this time to determine the severity of welding defects. The analysis has proved that, fabricated under proper conditions and with parameters of the welding process duly observed, the welded joint has good properties and repairs of this type are possible in practice.

  15. Transversely Compressed Bonded Joints

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Schmidt, Jacob Wittrup; Stang, Henrik

    2012-01-01

    The load capacity of bonded joints can be increased if transverse pressure is applied at the interface. The transverse pressure is assumed to introduce a Coulomb-friction contribution to the cohesive law for the interface. Response and load capacity for a bonded single-lap joint was derived using...... non-linear fracture mechanics. The results indicated a good correlation between theory and tests. Furthermore, the model is suggested as theoretical base for determining load capacity of bonded anchorages with transverse pressure, in externally reinforced concrete structures....

  16. Numerical and experimental assessment of stainless and carbon bolted tensioned members with staggered bolts Avaliação numérica e experimental de membros tracionados em aço carbono e aço inoxidável com parafusos defasados

    Directory of Open Access Journals (Sweden)

    João de Jesus dos Santos

    2013-06-01

    Full Text Available Current stainless steel design codes, like the Eurocode 3, part 1.4, (2006, are still largely based on analogies with carbon steel structural behavior. The net section rupture represents one of the ultimate limit states usually verified for structural elements submitted to normal tension stress. An investigation aiming to evaluate the tension capacity of carbon and stainless steel bolted structural elements was performed and in this article, the results are discussed and compared in terms of stress distribution, and force-displacement curves, among others. The result assessment was done by comparisons to the Eurocode 3 (2003 provisions for carbon and stainless steels. The investigation indicated that when stainless steel is used in certain structural engineering applications like joints under tension forces, the current design criteria based on deformation limits need to be re-evaluated, especially due to the differences in the yields for ultimate deformation and stress ratios.As normas atuais de projeto de estruturas em aço inoxidável, como o Eurocódigo 3, parte 1.4 (2006, são, em grande parte, baseadas em analogias assumidas com o comportamento de estruturas desenvolvidas com aço carbono. A ruptura da seção transversal representa um dos estados-limites últimos usualmente verificados para elementos estruturais submetidos a tensões normais de tração. Esse artigo apresenta uma investigação para se avaliar a resistência à tração de elementos aparafusados em aço carbono e aço inoxidável. Os resultados são discutidos e comparados em termos de distribuição de tensões, curvas carga-deslocamento, entre outros. Esses resultados foram comparados com as recomendações de projeto do Eurocódigo 3, para aço carbono e aço inoxidável, respectivamente. Essa investigação indicou que, quando o aço inoxidável é utilizado em certas aplicações da engenharia estrutural, como ligações submetidas a esforços de tração, o crit

  17. Seismic behavior and mechanism analysis of innovative precast shear wall involving vertical joints

    Institute of Scientific and Technical Information of China (English)

    孙建; 邱洪兴

    2015-01-01

    To study the seismic performance and load-transferring mechanism of an innovative precast shear wall (IPSW) involving vertical joints, an experimental investigation and theoretical analysis were successively conducted on two test walls. The test results confirm the feasibility of the novel joints as well as the favorable seismic performance of the walls, even though certain optimization measures should be taken to improve the ductility. The load-transferring mechanism subsequently is theoretically investigated based on the experimental study. The theoretical results show the load-transferring route of the novel joints is concise and definite. During the elastic stage, the vertical shear stress in the connecting steel frame (CSF) distributes uniformly;and each high-strength bolt (HSB) primarily delivers vertical shear force. However, the stress in the CSF redistributes when the walls develop into the elastic-plastic stage. At the ultimate state, the vertical shear stress and horizontal normal stress in the CSF distribute linearly;and the HSBs at both ends of the CSF transfer the maximum shear forces.

  18. Structural development of laminar flow control aircraft chordwise wing joint designs

    Science.gov (United States)

    Fischler, J. E.; Jerstad, N. M.; Gallimore, F. H., Jr.; Pollard, T. J.

    1989-01-01

    For laminar flow to be achieved, any protuberances on the surface must be small enough to avoid transition to turbulent flow. However, the surface must have joints between the structural components to allow assembly or replacement of damaged parts, although large continuous surfaces can be utilized to minimize the number the number of joints. Aircraft structural joints usually have many countersunk bolts or rivets on the outer surface. To maintain no mismatch on outer surfaces, it is desirable to attach the components from the inner surface. It is also desirable for the panels to be interchangeable, without the need for shims at the joint, to avoid surface discontinuities that could cause turbulence. Fabricating components while pressing their outer surfaces against an accurate mold helps to ensure surface smoothness and continuity at joints. These items were considered in evaluating the advantages and disadvantages of the joint design concepts. After evaluating six design concepts, two of the leading candidates were fabricated and tested using many small test panels. One joint concept was also built and tested using large panels. The small and large test panel deflections for the leading candidate designs at load factors up to +1.5 g's were well within the step and waviness requirements for avoiding transition.The small panels were designed and tested for compression and tension at -65 F, at ambient conditions, and at 160 F. The small panel results for the three-rib and the sliding-joint concepts indicated that they were both acceptable. The three-rib concept, with tapered splice plates, was considered to be the most practical. A modified three-rib joint that combined the best attributes of previous candidates was designed, developed, and tested. This improved joint met all of the structural strength, surface smoothness, and waviness criteria for laminar flow control (LFC). The design eliminated all disadvantages of the initial three-rib concept except for

  19. A symptomatic coracoclavicular joint

    NARCIS (Netherlands)

    Cheung, T.F.S.; Boerboom, A.L.; Wolf, R.F.E.; Diercks, Ron

    2006-01-01

    Bilateral coracoclavicular joints were found in a 44-year-old male patient following a fall. He had an Indonesian mother and a Dutch father. Prior to the injury he was asymptomatic and had full range of movement in both shoulders but the trauma resulted in pain and limitation of movement in the left

  20. Joint Custody and Coparenting.

    Science.gov (United States)

    Sell, Kenneth D.

    Results are presented of an intensive search of U.S. newspapers and periodicals on the joint custody of children after divorce, where both parents have continued responsibility for parenting and where the children spend part of each week, month, or year with both of the parents. Areas of concern addressed by these materials include the following:…

  1. 螺栓组拧紧顺序对结构体接触刚度的影响研究%Research on Influence of Contact Stiffness of Bolted Assembly Structure from Bolt-up Sequence

    Institute of Scientific and Technical Information of China (English)

    李培林; 王庆力; 王崴; 刘晓卫

    2014-01-01

    针对螺栓连接结构体接触刚度受拧紧顺序影响机理研究存在的不足,首先建立了单螺栓拧紧扭矩T与结合面刚度K的关联模型;然后在ANSYS中仿真分析了不同拧紧顺序下结合面模态频率特征,根据频率f与结合面刚度K之间的映射关系,进而得出最佳拧紧顺序;最后利用实验进行验证。结果表明,不同拧紧顺序结合面等效刚度K不同,结构的一阶固有频率也随之改变,同时拧紧最优、对角拧紧次之、顺序拧紧最差,说明拧紧顺序与固有频率之间存在着非线性关系。仿真分析与测试得到的一阶模态频率间的误差较小,证明了该建模方法能够有效分析拧紧顺序对结合面动力学性能的影响。%According to the existence problems of study on the mechanism of contact stiffness of bolted as-sembly structure formed by tightening sequence ( TS ) , a TK model of single bolt structure is established;then the frequency characteristics of combined surface under different TS was analyzed by using ANSYS;the optimal TS is obtained based on the frequency and the interface stiffness mapping. At last, a group of experiments was done to verify the above conclusions. The results show that the interface stiffness is verify under different TS, and so does the first rank natural frequency of the structure;the nonlinear response of the structure is significantly affected by TS that tighten at the same time is the optimal method compared with other TS. A small error of modal frequency between simulating and testing proves that the modeling method can effectively analyze impacts of the TS on the dynamic properties of the interface.

  2. Load-bearing Capacity Analysis Method for Explosive Bolt on Launch Vehicle%运载火箭爆炸螺栓承载能力分析方法

    Institute of Scientific and Technical Information of China (English)

    杨帆; 张希; 章凌; 曾杜娟; 郑卫东

    2015-01-01

    The transverse unlocking plane of fairing in launch vehicle is usually connected by explosive bolts. The empirical formula used for calculating explosive bolt strength is rash without considering local deformation effect. In this paper, finite-element method was adopted to stimulate the local deformation of explosive bolt which disclosed the mechanism of local deformation of explosive bolt. A method for calculating explosive bolt load-bearing capacity was proposed. By comparing with finite-element calculation results, the revised method can enhance the calculating precision of explosive bolt load-bearing capacity significantly.%运载火箭的整流罩横向解锁面一般采用爆炸螺栓连接,目前针对爆炸螺栓强度计算采用的是经验算法,由于没有考虑局部变形效应往往偏于冒进.采用有限元方法对爆炸螺栓的局部变形进行详细的仿真,揭示了爆炸螺栓结构的局部变形机理,并提出一种计算爆炸螺栓承载能力的方法,通过与有限元计算结果的对比,修正后的方法能够大幅提高爆炸螺栓承载力的计算精度.

  3. Stress Analysis of Building Curtain Wall Post Embedment Anchor Bolt%建筑幕墙后置埋件锚栓受力分析

    Institute of Scientific and Technical Information of China (English)

    陆新鑫; 吴强

    2014-01-01

    本文根据JGJ 145—2013《混凝土结构后锚固技术规程》第5.2.2条,对后置埋件在双向受弯矩、双向受剪力、以及扭矩、拉力的共同作用下进行的锚栓受力做了分析,提出了复合力作用下后置埋件锚栓的计算公式。%This paper, according to article 5.2.2 of JGJ 145 -2013 “technical specification for concrete structure of anch-oring force”, made an analysis of the force analysis of post anchor bolt under the interaction of bi-directional torque, shear force, bending, put ing forward the calculation formula of posts anchor bolt under composite force.

  4. Shoulder Joint For Protective Suit

    Science.gov (United States)

    Kosmo, Joseph J.; Smallcombe, Richard D.

    1994-01-01

    Shoulder joint allows full range of natural motion: wearer senses little or no resisting force or torque. Developed for space suit, joint offers advantages in protective garments for underwater work, firefighting, or cleanup of hazardous materials.

  5. Joint Infection (Beyond the Basics)

    Science.gov (United States)

    ... for some deep joints (eg, hip, shoulder), surgical placement of a drainage tube. ARTIFICIAL JOINT INFECTION — People ... medications, the user is advised to check the product information sheet accompanying each drug to verify conditions ...

  6. Joint cumulants for natural independence

    OpenAIRE

    Hasebe, Takahiro; Saigo, Hayato

    2011-01-01

    Many kinds of independence have been defined in non-commutative probability theory. Natural independence is an important class of independence; this class consists of five independences (tensor, free, Boolean, monotone and anti-monotone ones). In the present paper, a unified treatment of joint cumulants is introduced for natural independence. The way we define joint cumulants enables us not only to find the monotone joint cumulants but also to give a new characterization of joint cumulants fo...

  7. Nonlinear Progressive Damage Analysis of Notched or Bolted Fibre-Reinforced Polymer (FRP Laminates Based on a Three-Dimensional Strain Failure Criterion

    Directory of Open Access Journals (Sweden)

    Yue Liu

    2014-03-01

    Full Text Available Notching and bolting are commonly utilised in connecting fibre-reinforced polymer (FRP laminates. These mechanical methods are usually superior to other connections, particularly when joining thick composite laminates. Stress distributions, damage modes and ultimate strengths in notched or bolted FRP laminate designs are of particular interest to the industrial community. To predict the ultimate strengths and the failure processes of notched or bolted composite laminates, nonlinear progressive damage analyses (PDA based on the finite element method (FEM at the meso-scale level are performed in this paper. A three-dimensional strength criterion in terms of strains, which can distinguish different damage modes, was developed and adopted in the analysis model to detect damage initiation in the laminates. Different material degradation methods and the influence of cohesive layers were discussed and compared with results of verification experiments. The results showed that the analysis model that used the succinct strength criterion proposed in this paper could properly predict the damage initiation and the ultimate strengths of notched or bolted FRP laminates. The errors between the numerical results and experimental data were small. The material degradation method with continuum damage mechanics (CDM-based exponential damage factors using the damage index as the independent variable achieved greater accuracy and convergence than the method with CDM-based exponential damage factors using the square index as the independent variable or than the method with constant damage factors. Adding cohesive layers in the model had negligible influence on the final results, largely because the succinct analysis model proposed in this paper is sufficiently accurate in cases of small delamination.

  8. Further development of remote testing of submerged bolts and screws in reactors; Weiterentwicklung der ferngesteuerten Schrauben- und Stiftpruefung unter Wasser in Reaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Mohr, F.; Schirner, G.; Meier, R.; Wiesinger, W. [intelligeNDT Systems und Services, Erlangen (Germany)

    2007-07-01

    Since the eighties, intelligeNDT has been carrying out ultrasonic tests of bolts in reactor containments and pressure vessels both in Germany and abroad. The ultrasonic equipment used belonged to the SAPHIR/SAPHIRplus line. The recording and online evaluation software was adapted to the test requirements and optimized for high test rates and quality-assured documentation. As test manipulator, the 'SUSI' submarine by AREVA NP was used with good results. (orig.)

  9. Bending calculation analysis of composite beam with bolt connection%螺栓连接组合梁的弯曲计算

    Institute of Scientific and Technical Information of China (English)

    郭作杰

    2015-01-01

    由于螺栓连接组合梁的弯曲是一个静不定问题,一些文献把螺栓连接组合梁弯曲作为静定问题来处理,有时会导致螺栓连接组合梁叠层梁弯曲应力、弯曲挠度、螺栓剪力的计算结果存在很大的误差。本文按静不定问题研究了螺栓连接组合梁弯曲变形,导出了螺栓连接组合梁弯曲的弯曲应力、弯曲挠度、螺栓剪力计算公式。通过有限元法及实验验证了把螺栓连接组合梁弯曲作为静不定问题处理是正确的。%The bending of composite beam with bolt connection is a statically indeterminate problem in fact;some mechanics of materials textbooks related take it as statically determinate problem, which may lead to large calculation error for the bending stress, bending deflection and shear force of composite beam with bolt connection. By taking it as statically indeterminate structures, the calculation formula for bending stress, bending deflection and shear force of composite beam with bolt connection were derived. The finite element method and experiments verify that taking composite beam with bolt connection as a statically indeterminate problem is right.

  10. A feasibility study for experimentally determining dynamic force distribution in a lap joint.

    Energy Technology Data Exchange (ETDEWEB)

    Mayes, Randall Lee

    2013-11-01

    Developing constitutive models of the physics in mechanical joints is currently stymied by inability to measure forces and displacements within the joint. The current state of the art estimates whole joint stiffness and energy loss per cycle from external measured force input and one or two acceleration responses. To validate constitutive models beyond this state requires a measurement of the distributed forces and displacements at the joint interface. Unfortunately, introducing measurement devices at the interface completely disrupts the desired physics. A feasibility study is presented for a non-intrusive method of solving for the interface dynamic forces from an inverse problem using full field measured responses. The responses come from the viewable surface of a beam. The noise levels associated with digital image correlation and continuous scanning laser Doppler velocimetry are evaluated from typical beam experiments. Two inverse problems are simulated. One utilizes the extended Sum of Weighted Accelerations Technique (SWAT). The second is a new approach dubbed the method of truncated orthogonal forces. These methods are much more robust if the contact patch geometry is well identified. Various approaches to identifying the contact patch are investigated, including ion marker tracking, Prussian blue and ultrasonic measurements. A typical experiment is conceived for a beam which has a lap joint at one end with a single bolt connecting it to another identical beam. In a virtual test using the beam finite element analysis, it appears that the SWAT inverse method requires evaluation of too many coefficients to adequately identify the force distribution to be viable. However, the method of truncated orthogonal forces appears viable with current digital image correlation (and probably other) imaging techniques.

  11. Achieving joint benefits from joint implementation

    Energy Technology Data Exchange (ETDEWEB)

    Moomaw, W.R. [Tufts Univ., Medford, MA (United States)

    1995-11-01

    Joint Implementation (JI) appears to have been born with Applied Energy Services Guatemala project in 1988. That project, to plant 52 million trees, protect existing forests from cutting and fire, and enhance rural development, is being implemented by CARE Guatemala to offset 120 per cent of the emissions of a small coal burning power plant that has been built in Connecticut. Since that time, several utilities and governments have initiated additional projects. Not all of these necessarily consist of tree planting in other countries, but may consist of energy efficiency or energy conservation programs designed to reduce carbon emissions by at least as much as the additional releases from a new facility. All JI projects share the characteristic of linking the release of greenhouse gases in an industrial country with an offset that reduces or absorbs a comparable amount in another country. The emitter in the industrial country is willing to pay for the reduction elsewhere because costs are less than they would be at home.

  12. JOINT VENTURES AMONG EXPORTING FIRMS

    OpenAIRE

    CHAUDHURI, Prabal Ray

    2000-01-01

    In this paper we examine the incentive for joint venture formation among exporting firms. We show that an increase in domestic demand increases the incentive for joint venture formation. An increase in world price, however, can either increase or decrease the incentive for joint venture formation.

  13. 液压机常用地脚螺栓锚固方法%Common Anchoring Methods of Foundation Bolt for Hydraulic Press

    Institute of Scientific and Technical Information of China (English)

    魏征宇

    2011-01-01

    There are three common anchoring methods of foundation bolt for hydraulic press. The first is preburied bolt method, which is mainly used for anchoring of hook holt. The second is pre-buried anchor plate method,which is mainly used for anchoring of T-type foundation holt. The last is reserved hole method, which is mainly used for anchoring of anchor plate holt. The detailed applications of the above three methods in the hydraulic press have been introduced in the text. and the calculations of anchoring strength and depth have been put forward, as well as the. serewing.and unscrewing bolts.%液压机常用地脚螺栓锚固方法基本上有三种:①预埋螺栓法,主要用于弯钩螺栓的锚固;②预设锚板法,主要用于T形地脚螺栓的锚固;⑧预留孔法,主要用于锚板螺栓的锚固.本文详细介绍了这几种锚固方法在液压机中的应用、锚固强度和锚固深度的计算以及地脚螺栓的拧紧与防松.

  14. Joint hypermobility syndrome pain.

    Science.gov (United States)

    Grahame, Rodney

    2009-12-01

    Joint hypermobility syndrome (JHS) was initially defined as the occurrence of musculoskeletal symptoms in the presence of joint laxity and hypermobility in otherwise healthy individuals. It is now perceived as a commonly overlooked, underdiagnosed, multifaceted, and multisystemic heritable disorder of connective tissue (HDCT), which shares many of the phenotypic features of other HDCTs such as Marfan syndrome and Ehlers-Danlos syndrome. Whereas the additional flexibility can confer benefits in terms of mobility and agility, adverse effects of tissue laxity and fragility can give rise to clinical consequences that resonate far beyond the confines of the musculoskeletal system. There is hardly a clinical specialty to be found that is not touched in one way or another by JHS. Over the past decade, it has become evident that of all the complications that may arise in JHS, chronic pain is arguably the most menacing and difficult to treat. PMID:19889283

  15. JET Joint Undertaking

    International Nuclear Information System (INIS)

    The paper presents the annual report of the Joint European Torus (JET) Joint Undertaking, 1986. The report is divided into two parts: a part on the scientific and technical programme of the project, and a part setting out the administration and organisation of the Project. The first part includes: a summary of the main features of the JET apparatus, the JET experimental programme, the position of the Project in the overall Euratom programme, and how JET relates to other large fusion devices throughout the world. In addition, the technical status of JET is described, as well as the results of the JET operations in 1986. The final section of the first part outlines the proposed future programme of JET. (U.K.)

  16. Laundry joint venture.

    Science.gov (United States)

    Giancola, D; Voyvodich, M

    1984-12-01

    Many hospitals are concerned about the loss of control which is associated with contracting for linen service. On the the hand, many laundries do not have the resources or experience to serve hospitals in a comprehensive and trouble-free manner. In many communities a joint venture, such as the one described here, can successfully combine the interests of the hospital and laundry communities without causing the hospitals to lose control of the service and without requiring the laundry operator to have detailed knowledge of hospital operations. As more hospitals opt for contract service, and if this service is to be provided at the lowest total cost, the hospitals and the laundries must come to grips with the problems surrounding the laundry-hospital interface. A joint venture, such as that described here, is one way to accomplish this.

  17. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  18. Posttraumatic Temporomandibular Joint Disorders

    OpenAIRE

    Giannakopoulos, Helen E.; Quinn, Peter D.; Granquist, Eric; Chou, Joli C.

    2009-01-01

    The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding,...

  19. The Joint Cities

    Directory of Open Access Journals (Sweden)

    Romano Fistola

    2010-04-01

    Full Text Available The new connections, which high speed train allows to activate among the metropolitan systems, seem to be able to give life to new urban macro-structures for which the transfer time, among the main poles of the railway segment, becomes comparable to an inside moving into the city and therefore considered as an inter-functional mobility. The tunnel effect generated by the high speed connection seems to be able to allow a new temporal and functional joint among the metropolitan systems consequently supporting the possibility, for the users, to move themselves among the different urban functions belonging to the different cities. The birth of these urban aggregations seems to drive towards new megalopolis, which we can define for the first time with the term: joint-city. For this new metropolitan settlement it seems to be very interesting to investigate the constitutive peculiarities, the systemic articulation, its relational structures, the evolutionary scenarios, and so on. The urban functions (activities can be considered as structures of relationships between people that allows to define "organizational links" inside the community; the urban functions are located in specific places inside urban container or in open spaces. The urban functions represent the urban engines and the functional system can be thought as the “soul of the city", abstract but essential to its survival. In the definition set out here the analysis is carried out for many interconnected urban functional system points (specifically those in Rome and Naples. The new high speed railway has to be considered not only as a new channel of mobility between cities, but as a real possibility of joint between the functional systems of the two centres. A final consideration can be carried out in relation to the possibility of implementing new measures of governance of urban transformations considering the new macro-city: the "Joint City".

  20. Jet Joint Undertaking

    International Nuclear Information System (INIS)

    The paper presents the Jet Joint Undertaking annual report 1987. A description is given of the JET and Euratom and International Fusion Programmes. The technical status of JET is outlined, including the development and improvements made to the system in 1987. The results of JET Operation in 1987 are described within the areas of: density effects, temperature improvements, energy confinement studies and other material effects. The contents also contain a summary of the future programme of JET. (U.K.)

  1. Shoulder joint tuberculosis

    International Nuclear Information System (INIS)

    Despite the fact that joint tuberculosis is one of the most common forms of extrapulmonary tuberculosis, it is a disease entity that is very rare in Poland (less than 100 cases a year in the last 10 years). The symptoms are non-specific, and thus the disease is rarely taken into account in preliminary differential diagnosis. A 68-year-old female patient was admitted to the Internal Diseases Clinic due to oedema and pain of the right shoulder joint. The pain has been increasing for about 8 months. Physical examination revealed increased circumference and elevated temperature of the right shoulder joint. Limb function was retained. The full range of radiological and laboratory diagnostic examinations was performed, including the biopsy of the affected tissue which revealed the presence of Mycobacterium tuberculosis in the bacterial culture. Clinical improvement was obtained after introduction of TB drugs. Radiological diagnostic methods (X-ray, CT scans, MRI scans) provide high precision monitoring of articular lesions. However, the decisive diagnosis requires additional laboratory tests as well as histopathological and bacteriological assays

  2. The neuropathic joint.

    Science.gov (United States)

    Sequeira, W

    1994-01-01

    Neuropathic arthritis is a destructive arthropathy frequently associated with loss of proprioception. A third of patients, however, may have no demonstrable neurological deficit. Patients with diabetes, syphilis, syringomyelia and other neuropathies are particularly prone to developing this joint disease. The diagnosis of Charcot's joints should be considered in anyone who develops what appears to be a severe osteoarthritis or a transverse fracture of the tibia or fibula after minor trauma. Scoliosis with particularly destructive changes on radiography should prompt a search for syringomyelia or syphilis. The most common radiographic abnormalities are those of distension in 3D (Dislocation, Destruction and Degeneration). An atrophic form with resorption of the proximal humerus, most frequently described in syringomyelia, has been observed in diabetes. Loss of the distal end of the clavicle has not been described before in the neuropathies. These changes coupled with speckled calcification or shards of bone in the periarticular soft tissue confirm the diagnosis. Infection and CPPD crystal disease can be difficult to exclude. The joint fluid may be inflammatory and infection may be a complication. Treatment includes anti-inflammatories and splinting. Indications for surgery are limited. PMID:8070170

  3. Formation of tough composite joints

    Energy Technology Data Exchange (ETDEWEB)

    Brun, M.K. [GE Corporate Research and Development, Schenectady, NY (United States)

    1997-05-01

    Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si{sub 3}N{sub 4}-coated fibers had a 0/90{degree} architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses.

  4. Laboratory characterization of rock joints

    International Nuclear Information System (INIS)

    A laboratory characterization of the Apache Leap tuff joints under cyclic pseudostatic and dynamic loads has been undertaken to obtain a better understanding of dynamic joint shear behavior and to generate a complete data set that can be used for validation of existing rock-joint models. Study has indicated that available methods for determining joint roughness coefficient (JRC) significantly underestimate the roughness coefficient of the Apache Leap tuff joints, that will lead to an underestimation of the joint shear strength. The results of the direct shear tests have indicated that both under cyclic pseudostatic and dynamic loadings the joint resistance upon reverse shearing is smaller than that of forward shearing and the joint dilation resulting from forward shearing recovers during reverse shearing. Within the range of variation of shearing velocity used in these tests, the shearing velocity effect on rock-joint behavior seems to be minor, and no noticeable effect on the peak joint shear strength and the joint shear strength for the reverse shearing is observed

  5. Laboratory characterization of rock joints

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, S.M.; Kana, D.D.; Ahola, M.P.; Chowdhury, A.H.; Ghosh, A. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1994-05-01

    A laboratory characterization of the Apache Leap tuff joints under cyclic pseudostatic and dynamic loads has been undertaken to obtain a better understanding of dynamic joint shear behavior and to generate a complete data set that can be used for validation of existing rock-joint models. Study has indicated that available methods for determining joint roughness coefficient (JRC) significantly underestimate the roughness coefficient of the Apache Leap tuff joints, that will lead to an underestimation of the joint shear strength. The results of the direct shear tests have indicated that both under cyclic pseudostatic and dynamic loadings the joint resistance upon reverse shearing is smaller than that of forward shearing and the joint dilation resulting from forward shearing recovers during reverse shearing. Within the range of variation of shearing velocity used in these tests, the shearing velocity effect on rock-joint behavior seems to be minor, and no noticeable effect on the peak joint shear strength and the joint shear strength for the reverse shearing is observed.

  6. FINITE ELEMENT NUMERICAL SIMULATION OF BOLT CONNECTION%钢结构螺栓连接的有限元数值模拟

    Institute of Scientific and Technical Information of China (English)

    王智

    2013-01-01

    螺栓连接是钢结构连接的主要方式之一,具有施工简单、拆装方便等优点.现行钢结构规范中对螺栓连接的计算都是在一定的假设条件下进行的.本文以钢结构规范中的计算公式为基础,运用有限元数值分析的方法,采用ABAQUS来分析普通螺栓群在受剪和受拉条件下的各个螺栓的受力情况.将有限元软件模拟的结果与公式计算结果进行比较,证明规范公式的正确性.文中分别模拟分析了普通螺栓群在受剪的情况下承受轴心力、扭矩,和普通螺栓群在受拉的情况下承受拉力、弯矩的受力情况.%The bolt connection as one of the main ways of steel connection, has advantages of simple construction, easy demolition and so on. The calculation of bolt connection is in a certain hypothesis conditions in the current code. This article is based on calculation formulas included in code for design of steel structures, it is adopted that finite element analysis method and the software ABAQUS to analyse the behaviours of the ordinary bolt group which are in shear and tensile conditions. Then, the simulation results and the outcome calculated by formulas are compared in order to prove the correctness of the formulas of the code. The paper analyses the behaviours of the bolt group in the case of bearing shear force and torque. At the same time , it is also analysed that the behaviours of the bolt group in the case of tension and moment

  7. Assessment and evaluation of noise controls on roof bolting equipment and a method for predicting sound pressure levels in underground coal mining

    Science.gov (United States)

    Matetic, Rudy J.

    Over-exposure to noise remains a widespread and serious health hazard in the U.S. mining industries despite 25 years of regulation. Every day, 80% of the nation's miners go to work in an environment where the time weighted average (TWA) noise level exceeds 85 dBA and more than 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the permissible exposure limit (PEL). Additionally, MSHA coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage comprise only seven different types of machines; auger miners, bulldozers, continuous miners, front end loaders, roof bolters, shuttle cars (electric), and trucks. In addition, the MSHA data indicate that the roof bolter is third among all the equipment and second among equipment in underground coal whose operators exceed 100% dosage. A research program was implemented to: (1) determine, characterize and to measure sound power levels radiated by a roof bolting machine during differing drilling configurations (thrust, rotational speed, penetration rate, etc.) and utilizing differing types of drilling methods in high compressive strength rock media (>20,000 psi). The research approach characterized the sound power level results from laboratory testing and provided the mining industry with empirical data relative to utilizing differing noise control technologies (drilling configurations and types of drilling methods) in reducing sound power level emissions on a roof bolting machine; (2) distinguish and correlate the empirical data into one, statistically valid, equation, in which, provided the mining industry with a tool to predict overall sound power levels of a roof bolting machine given any type of drilling configuration and drilling method utilized in industry; (3) provided the mining industry with several approaches to predict or determine sound pressure levels in an underground coal mine utilizing laboratory test results from a roof bolting

  8. The Use of the Direct Optimized Probabilistic Calculation Method in Design of Bolt Reinforcement for Underground and Mining Workings

    Directory of Open Access Journals (Sweden)

    Martin Krejsa

    2013-01-01

    Full Text Available The load-carrying system of each construction should fulfill several conditions which represent reliable criteria in the assessment procedure. It is the theory of structural reliability which determines probability of keeping required properties of constructions. Using this theory, it is possible to apply probabilistic computations based on the probability theory and mathematic statistics. Development of those methods has become more and more popular; it is used, in particular, in designs of load-carrying structures with the required level or reliability when at least some input variables in the design are random. The objective of this paper is to indicate the current scope which might be covered by the new method—Direct Optimized Probabilistic Calculation (DOProC in assessments of reliability of load-carrying structures. DOProC uses a purely numerical approach without any simulation techniques. This provides more accurate solutions to probabilistic tasks, and, in some cases, such approach results in considerably faster completion of computations. DOProC can be used to solve efficiently a number of probabilistic computations. A very good sphere of application for DOProC is the assessment of the bolt reinforcement in the underground and mining workings. For the purposes above, a special software application—“Anchor”—has been developed.

  9. Experimental Study on a New Bolt Connnection Used in Mutti-story Fabricated Steel Structure%多层预拼装钢结构系统特殊连接螺栓抗剪性能试验研究

    Institute of Scientific and Technical Information of China (English)

    张齐; 张其林; 丁娟

    2014-01-01

    A new kind of bolt connection consisted of self-tapping steel plate and high strength bolt will be used in a multistory fabricated steel structure system .But there are no regulations on such kind of bolted con-nection .Therefore ,extensive experimental research on bolted connection was taken .The objective of the re-search was to determine the ductility and resistance of such connection .The failure mode of bolted connections could be observed in the test .The ultimate bearing capacities of friction type high-strength bolt and bearing type high-strength bolt are different due to different design provisions and both bearing capacities were dotained in this experiment .The ultimate bearing capacities were compared with that predicted by the current connec-tion provisions specified in china steel design standards .%某新型多层预拼装钢结构系统采用了钢板自攻螺纹螺栓连接形式,超出现行规范中连接类型,需进行相关试验进行论证,针对工程常用6种规格高强螺栓自攻螺纹连接进行了单个螺栓抗剪试验,研究了此种连接的抗剪破坏模式,并依据摩擦型高强螺栓及承压型高强螺栓不同的设计假定确定两种情况下的极限承载力,与规范要求承载力设计值进行比对,为该种新型螺栓连接提供设计依据。

  10. Joint Advisory Appeals Board

    CERN Multimedia

    2003-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Poul Frandsen concerning his assimilation into the new career structure. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 13 to 24 January 2003. Human Resources Division Tel. 74128

  11. Posttraumatic temporomandibular joint disorders.

    Science.gov (United States)

    Giannakopoulos, Helen E; Quinn, Peter D; Granquist, Eric; Chou, Joli C

    2009-05-01

    The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding, and with opposing approaches. The following article explores various treatment options for problems presenting as a result of a history of trauma to the TMJ. PMID:22110802

  12. THE JOINT MONITORING COMMISSION

    Directory of Open Access Journals (Sweden)

    Helmoed-Römer Heitman

    2012-02-01

    Full Text Available The Joint Monitoring Commission (JMC was created to oversee the withdrawal of South African forces from the portion of Angola's southern Cunene province in which they had operated for some time, and its re-occupation by the Angolan Armed Forces (Fapla. It was to ensure that neither Swapo nor Cuban forces moved into this area as the South African Defence Force (SADF withdrew. The JMC consisted of SADF and Fapla headquarters (HQ personnel and infantry from both armies to monitor the area concerned. It operated in southern Angola from February 1984 to May 1985.

  13. Joint Advisory Appeals Board

    CERN Multimedia

    2003-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Aloïs Girardoz with regard to classification and advancement. As the appellant has not objected, the Board's report and the Director-General's decision will be brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 15 to 29 August 2003. Human Resources Division Tel. 74128

  14. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Personnel Division

    1999-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Joào Bento with regard to residential category. As the appellant has not objected, the recommendations of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article RÊVIÊ1.20 of the Staff Regulations.The relevant documents will therefore be posted on the notice boards of the Administration Building (N¡ 60) from 29 October to 12 November 1999.Personnel DivisionTel. 74128

  15. Surgery center joint ventures.

    Science.gov (United States)

    Zasa, R J

    1999-01-01

    Surgery centers have been accepted as a cost effective, patient friendly vehicle for delivery of quality ambulatory care. Hospitals and physician groups also have made them the vehicles for coming together. Surgery centers allow hospitals and physicians to align incentives and share benefits. It is one of the few types of health care businesses physicians can own without anti-fraud and abuse violation. As a result, many surgery center ventures are now jointly owned by hospitals and physician groups. This article outlines common structures that have been used successfully to allow both to own and govern surgery centers.

  16. Acromioclavicular Joint Reconstruction.

    Science.gov (United States)

    Scillia, Anthony J; Cain, E Lyle

    2015-12-01

    Our technique for acromioclavicular joint reconstruction provides a variation on coracoclavicular ligament reconstruction to also include acromioclavicular ligament reconstruction. An oblique acromial tunnel is drilled, and the medial limb of the gracilis graft, after being crossed and passed beneath the coracoid and through the clavicle, is passed through this acromial tunnel and sutured to the trapezoid graft limb after appropriate tensioning. Tenodesis screws are not placed in the bone tunnels to avoid graft fraying, and initial forces on the graft are offloaded with braided absorbable sutures passed around the clavicle. PMID:27284528

  17. Optical rotary joint

    Science.gov (United States)

    May, R. G., Jr.

    1982-06-01

    The primary objective of this contract is the design, fabrication, and testing of an optical rotary joint which permits transmission of signals through optical fibers across the interface of two environments rotating relative to each other. Outstanding optical performance is achieved through the use of gradient index lenses to couple radiation across the separation between two fibers. The salient features of this device are bidirectional operation at two wavelengths (850 nm and 1300 nm), low insertion loss, low rotationally induced variation of attenuation, a seven-circuit electrical slip-ring assembly, and rugged construction. The device is designed to facilitate the application of future designs to pressurized, subsea environments.

  18. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel against the decision to grant him only a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main building (bldg. 500) from 1 September to 14 September 2008. Human Resources Department (73911)

  19. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel against the decision to grant him only a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main Building (Bldg. 500) from 1 September to 14 September 2008. Human Resources Department (73911)

  20. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2007-01-01

    The Joint Advisory Appeals Board was convened to examine an internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has requested that the report of the Board and the final decision of the Director-General be brought to the notice of the members of the personnel, in accordance with Article R VI 1.18 of the Staff Regulations. The relevant documents will therefore be posted on the notice board of the Main building (Bldg. 60) from 24 September to 7 October 2007. Human Resources Department

  1. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main Building (Bldg. 500) from 26 May to 6 June 2008. Human Resources Department (73911)

  2. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board was convened to examine an internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel, in accordance with Article R VI 1.18 of the Staff Regulations. These documents will therefore be posted on the notice board of the Main Building (Bldg. 60) from 21 January to 3 February 2008. Human Resources Department (73911)

  3. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2006-01-01

    The Joint Advisory Appeals Board was convened to examine an appeal lodged by a member of the personnel with regard to advancement. The person concerned has requested that the report of the Board and the final decision of the Director-General be brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (No. 60) from 24 March to 10 April 2006. Human Resources Department Tel. 74128

  4. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel with regard to the decision not to award him a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main building (Bldg. 500) from 17 March to 30 March 2008. Human Resources Department Tel. 73911

  5. Joint Advisory Appeals Board

    CERN Multimedia

    2013-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a former member of the personnel, a beneficiary of the CERN Pension Fund, against the calculation of his pension in the framework of the Progressive Retirement Programme.   The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be available from 26 July to 11 August 2013 at the following link. HR Department Head Office

  6. Lisfranc Joint Injuries

    Institute of Scientific and Technical Information of China (English)

    Lisa Chinn

    2009-01-01

    @@ The ankle and foot are the most common sites for athletic injuries.[1]Midfoot,or Lisfranc,injuries are the second most common foot injury and have a high in cidence in particular sports.They account for 4% of all football injuries per year,occurring frequently in linemen.[2]They are also common in equestrians,surfers,and windsurfers.[2]Lisfranc injuries are often misdiagnosed and if not treated properly can have lingering symptoms.It is estimated that Lisfranc joint injuries occur in 1 in every 55,000 persons every year.[3,4

  7. Jointly Sponsored Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Everett A. Sondreal; John G. Hendrikson; Thomas A. Erickson

    2009-03-31

    U.S. Department of Energy (DOE) Cooperative Agreement DE-FC26-98FT40321 funded through the Office of Fossil Energy and administered at the National Energy Technology Laboratory (NETL) supported the performance of a Jointly Sponsored Research Program (JSRP) at the Energy & Environmental Research Center (EERC) with a minimum 50% nonfederal cost share to assist industry in commercializing and effectively applying highly efficient, nonpolluting energy systems that meet the nation's requirements for clean fuels, chemicals, and electricity in the 21st century. The EERC in partnership with its nonfederal partners jointly performed 131 JSRP projects for which the total DOE cost share was $22,716,634 (38%) and the nonfederal share was $36,776,573 (62%). Summaries of these projects are presented in this report for six program areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, and (6) advanced materials. The work performed under this agreement addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration; near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources.

  8. Joint collaborative technology experiment

    Science.gov (United States)

    Wills, Michael; Ciccimaro, Donny; Yee, See; Denewiler, Thomas; Stroumtsos, Nicholas; Messamore, John; Brown, Rodney; Skibba, Brian; Clapp, Daniel; Wit, Jeff; Shirts, Randy J.; Dion, Gary N.; Anselmo, Gary S.

    2009-05-01

    Use of unmanned systems is rapidly growing within the military and civilian sectors in a variety of roles including reconnaissance, surveillance, explosive ordinance disposal (EOD), and force-protection and perimeter security. As utilization of these systems grows at an ever increasing rate, the need for unmanned systems teaming and inter-system collaboration becomes apparent. Collaboration provides a means of enhancing individual system capabilities through relevant data exchange that contributes to cooperative behaviors between systems and enables new capabilities not possible if the systems operate independently. A collaborative networked approach to development holds the promise of adding mission capability while simultaneously reducing the workload of system operators. The Joint Collaborative Technology Experiment (JCTE) joins individual technology development efforts within the Air Force, Navy, and Army to demonstrate the potential benefits of interoperable multiple system collaboration in a force-protection application. JCTE participants are the Air Force Research Laboratory, Materials and Manufacturing Directorate, Airbase Technologies Division, Force Protection Branch (AFRL/RXQF); the Army Aviation and Missile Research, Development, and Engineering Center Software Engineering Directorate (AMRDEC SED); and the Space and Naval Warfare Systems Center - Pacific (SSC Pacific) Unmanned Systems Branch operating with funding provided by the Joint Ground Robotics Enterprise (JGRE). This paper will describe the efforts to date in system development by the three partner organizations, development of collaborative behaviors and experimentation in the force-protection application, results and lessons learned at a technical demonstration, simulation results, and a path forward for future work.

  9. Safety aspects of joints and coatings for plasma facing components with composite structures

    Energy Technology Data Exchange (ETDEWEB)

    Zucchetti, M.; Ferraris, M. E-mail: ferraris@athena.polito.it; Salvo, M

    2001-11-01

    Silicon carbide fibres silicon carbide matrix (SiC/SiC) composites are among the most promising materials for high temperature applications, but they cannot be joined by traditional ways because they do not melt and the typical mechanical joints (rivets, bolts, etc.) are ineffective with these new materials: this is a problem for the preparation of complex structures, such as those of plasma-facing components (PFCs) for fusion reactors. Furthermore, these composites show a poor resistance towards the oxidation, they are porous and permeable to fluids. PFCs made of composite materials and in which joints and coatings are made with advanced materials pose some new problems regarding their safety. In particular, the following aspects have been addressed in this paper: (a) tritium inventory; (b) activated dust in plasma chamber; (c) accident-relevant low-activation properties; and (d) long-term relevant low-activation properties. As a result of all the above mentioned aspects, some safety-relevant guidelines for the choice of joining and coating materials for PFCs are finally discussed.

  10. Tapered joint design for power transmission of MW-grade wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jong Hun; Bae, Jun Woo; Oh, Han Yong [Dept. of Mechatronics, Jungwon University, Geosan (Korea, Republic of); Kwon, Yong Chul [Kyeongnam Technopark, Changwon (Korea, Republic of)

    2015-11-15

    This study focuses on the design of the tapered joints of a wind power turbine. The main variables of the tapered joint are the transmitted torque, shaft diameter, contact area of the tapered ring, and tightening torque of the bolts, which applies a compressive pressure from the hub to the shaft. The stress distribution of the taper fit was calculated under axisymmetric plane strain conditions because of the small taper angle. The axial displacement of the clamp can be calculated from the radial elastic deformation and the taper angle. The stress field of each ring is obtained from the cylinder stress equation. To verify the accuracy of the calculation, finite element (FE) analysis was performed, and the results of the calculation and FE analysis were compared. The hoop stress of the tapered surface showed a discrepancy of approximately 10, but the trends of the stress distributions of each component and the relative movement obtained by FE analysis were in good agreement with the analytical calculation results.

  11. OIG targets contractual joint ventures.

    Science.gov (United States)

    O'Hare, Patrick K

    2003-09-01

    A recent OIG Special Advisory Bulletin raises questions for providers involved in joint ventures. The Bulletin describes several characteristics that the OIG views as potentially suspect, including a referral stream controlled by the provider initiating the joint venture and the use of a wholly owned subsidiary of the provider to bill and collect for services. According to the OIG, profits paid by the subsidiary to the provider owner in such "suspect contractual joint ventures" could constitute illegal remuneration for referrals.

  12. Arthrography of the knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Keyl, W.; Jaeger, M.

    1981-10-01

    The standardized examination technique and the clinical problems of the arthrographic mehtod applied on the knee joint is explained by the results obtained in 3000 examinations. Whereas the accuracy of the knee-joint arthrography provides a high degree in cases of meniscus lesions, computer tomography presents in chondral and capsular ligament lesions, and sonography in popliteal cysts better diagnostic information; but in any case arthroscopy gains more and more importance in knee-joint diagnostics.

  13. Goniometry in limited joint mobility

    OpenAIRE

    Gopinath, S.; Manoj, K.; Rubiya

    2012-01-01

    Aim: To study about the utility of goniometry in screening for limited joint mobility (LJM) in patients attending a secondary level Diabetic Clinic. Materials and Methods: Randomly selected data of 100 patients attending a secondary level diabetic clinic without any complications were used. Baseline neuropathy assessments, namely monofilament and biothesiometry were done. Range of movement around the ankle joint and 1 st metatarsal joint was done using goniometry. Both the results were compar...

  14. Variable Joint Elasticities in Running

    Science.gov (United States)

    Peter, Stephan; Grimmer, Sten; Lipfert, Susanne W.; Seyfarth, Andre

    In this paper we investigate how spring-like leg behavior in human running is represented at joint level. We assume linear torsion springs in the joints and between the knee and the ankle joint. Using experimental data of the leg dynamics we compute how the spring parameters (stiffness and rest angles) change during gait cycle. We found that during contact the joints reveal elasticity with strongly changing parameters and compare the changes of different parameters for different spring arrangements. The results may help to design and improve biologically inspired spring mechanisms with adjustable parameters.

  15. TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND GENERALIZED JOINT HYPERMOBILITY

    NARCIS (Netherlands)

    DIJKSTRA, PU; DEBONT, LGM; STEGENGA, B; BOERING, G

    1992-01-01

    Peripheral joint mobility of temporomandibular joint (TMJ) osteoarthrosis and internal derangement patients (n = 25) and of a control group (n = 29) was measured according to a rigidly standardized protocol, in order to study the relationships between TMJ osteoarthrosis and internal derangement and

  16. Index of Joint Condition for PVC push-fit joints

    NARCIS (Netherlands)

    Arsenio, A.M.; Vreeburg, J.H.G.; Rietveld, L.

    2014-01-01

    The Index of Joint Condition (IJC) for polyvinyl chloride (PVC) push-fit joints, discussed in this article, was derived from installation guidelines and from destructive laboratory tests. The IJC is presented in a graphical framework and is a powerful tool to employ in order to visualize and compare

  17. 温度对树脂锚杆锚固性能影响研究%Study on Influence of Temperature on Anchorage Performance of Resin Anchored Bolt

    Institute of Scientific and Technical Information of China (English)

    胡滨; 康红普; 林健; 蔡嘉芳; 姜鹏飞

    2012-01-01

    为了分析在靠近自燃发火区的巷道进行锚杆支护时,树脂锚杆锚固力降低的现象,采用实验室试验和数值模拟相结合的方法进行了温度对树脂锚杆锚固性能的影响研究.不同温度下树脂锚杆拉拔试验结果表明:温度对树脂锚杆锚固性能影响比较大,温度为25℃时树脂锚杆锚固力最大,随着模拟钻孔温度的升高,树脂锚杆锚固力呈现明显递减规律;运用FLAC3D有限差分程序对单根锚杆支护小范围锚固系统的数值模拟结果表明:岩体应力场与温度场之间存在一定程度上的耦合作用,在相同外载荷作用下,热源温度不同,岩体应力分布状态也不同.在上述研究基础上,指出温度变化对岩体物理力学性质以及树脂锚固剂固化反应过程都会产生一定的影响,并提出了不同温度环境下保证锚杆支护效果的技术途径.%To analyze the phenomenon that anchoring force of resin anchored bolt often decreased where rock bolting was carried out in the roadway near spontaneous combustion region, we studied the influence of temperature on anchoring performance of resin anchored bolts in this paper, by using the comprehensive research of laboratory test and numerical simulation. The results of pull-out tests of resin anchored bolts under different temperatures show that temperatures have great influence on anchorage performance of resin anchored bolt. The anchoring force is the largest when the temperature is 25 °C, and the anchoring force descends obviously with the borehole temperature increases. Additionally, FLAC3D was adopted to simulate and analyze the anchorage system of single bolt support small-scale, and the results show that the coupled multi-physics processes exist to a certain extent between the stress field and temperature field of rock mass. The stress distribution states of rock mass are different under the same external load when the temperatures of heat source are different. On the

  18. Temporomandibular joint arthrography

    International Nuclear Information System (INIS)

    The stress and occlusion disturbance are very important etiologic factors in the temporomandibular joint (TMJ) pain dysfunction syndromes. Authors performed TMJ arthrograms in the patients with TMJ problem such as pain, click sound, limited motion and locking, etc. The following results noted: 1. The arthrographic findings of 22 TMJ were analyzed. a) Normal: 6 cases b) Anterior disc displacement with rediction: 6 cases · Early reduction: 2 cases · Intermediate reduction: 3 cases · Late reduction: 1 case c) Anterior disc displacement without reduction: 6 cases · Two cases had adhesion between the posterior portion of disc and the posterior surfaces of the articular eminence. 2. Among 22 cases, the clinical findings of 16 cases (73%) were compatible with arthrographic findings. 6 cases showed disparity between them.

  19. 爆炸螺栓预紧力对冲击响应影响分析%Influence of pretightening force of explosive bolts on impulse response

    Institute of Scientific and Technical Information of China (English)

    黄含军; 王军评; 毛勇建; 岳晓红; 吕剑

    2015-01-01

    爆炸分离冲击环境地面模拟试验中一般通过悬挂试验实现。试验中连接两分离部件的爆炸螺栓预紧力可能会对分离冲击响应产生影响。爆炸螺栓预紧力由螺栓安装拧紧力矩与分离下件重量产生,通过分析该力矩及该重量变化研究预紧力对响应影响。通过数值模拟、试验研究,分别在时、频域对响应影响进行分析。结果表明,爆炸螺栓安装力矩及分离下件重量在一定范围内的变化对中远场冲击响应影响较小。%The pyroshock simulation test on the ground is usually achieved through a hanging test.In the test,two separation parts are connected by explosive bolts,and the pretightening force of explosive bolts may have influence on impulse response during a pyroshock event.The pretightening force determined by the tightening torque and the weight of the lower separation part were considered as two important influential factors in the investigation.A FE numerical simulation and a hanging test were carried out.Different tightening torques and separation part weights were considered. The experimental results were analyzed both in time and frequency domain.Both the simulation and experimental results indicate that the influence of thoses two factors is limited in the mid-field and far-field of the bolts explosion.

  20. Discussion on the Installation Position of the Locknut of the Puller Bolt%顶紧螺栓的防松螺母安装位置探讨

    Institute of Scientific and Technical Information of China (English)

    李文鹏

    2016-01-01

    顶紧螺栓配合防松螺母的结构在工程实际中得到广泛应用,防松螺母安装在顶紧螺栓的工作面侧和非工作面侧都比较常见,本文分析了这两种安装方式的螺旋副受力情况,认为两种方式各有优劣。安装在非工作面侧时,螺母预紧力的操作方向和螺栓的顶紧操作方向一致,拆卸方向也一致,操作方便,但是需要的预紧力要大于受到的外力;安装在工作面侧时,螺母预紧力的操作方向和螺栓的顶紧操作方向相反,拆卸方向也相反,防松效果较好,但是需要从工艺上保证防松效果。%In the engineering practice, the structure of the puller bolt and locknut is widely used. It is common in the working face and non working side of the bolt. This paper analyzes the two kinds of screw pair force condition, and thinks that the two methods have their own advantages and disadvantages. Installed in the non working side, nuts pretightening force operating direction and bolt top tight operating in the same direction, disassembly direction, easy to operate, but need to preload to greater than by force; installed in the side of the working face, nuts pretightening force operating direction and bolt the top tight operating in the opposite direction, disassembly direction is opposite, anti loosening effect is good, but need to from process ensure locking effect.

  1. 非金属垫片螺栓法兰连接寿命评价%Life Assessment of Non-metallic Gasket Bolted Flanged Connections 

    Institute of Scientific and Technical Information of China (English)

    孙振国; 顾伯勤

    2011-01-01

    分析非金属垫片密封的时效特性,考虑高温条件下材料退化和垫片载荷松弛过程对密封性能的影响,依据多孔介质理论,建立非金属垫片密封的时效泄漏模型.将螺栓法兰连接系统寿命划分为密封寿命和部件寿命.提出密封寿命试验方法,在考虑垫片泄漏特性变化的基础上,基于指标泄漏率分析螺栓法兰连接系统密封寿命;基于蠕变和疲劳损伤准则分析高温螺栓的剩余寿命,探讨螺栓法兰连接系统的密封寿命和各部件寿命之间的关系.建立螺栓法兰连接系统的寿命预测最弱环模型,将垫片的变形特性和泄漏特性统一于螺栓法兰连接系统中进行研究,提出基于指标泄漏率和结构完整性的螺栓法兰连接系统寿命评价方法.%The time-correlated leakage characteristic of nonmetallic gaskets was analyzed. Considering the effect of the gasket compressive stress relaxation and the deterioration of material on gasket sealing performance at elevated temperature,a time-correlated leakage prediction model of non-metallic gasket sealing connections based on the porous medium theory was proposed. The life of bolted flanged connections was divided into sealing life and component life. A testing method of sealing life was put forward,the sealing life can be predicted based on target leakage rate in considering the change of gasket leakage characteristic,and the life of bolts can be obtained based on creep and fatigue damage criterion. The relationship between sealing life and component life of sealing system was discussed, and a weakest-link model for predicting the life of bolted flanged connections was established. A life evaluation method of bolted flanged connections based on the target leakage rate and the structural integrity was proposed, in which the deformation and leakage characteristic of the sealing system were both taken into consideration.

  2. Sonidegib for the treatment of advanced basal cell carcinoma: a comprehensive review of sonidegib and the BOLT trial with 12-month update.

    Science.gov (United States)

    Chen, Leon; Silapunt, Sirunya; Migden, Michael R

    2016-09-01

    The Hedgehog inhibitors are promising alternative for patients with advanced basal cell carcinoma that are not amenable to radiotherapy or surgery. Sonidegib, also known as LDE225, is an orally available SMO antagonist that was recently approved by the US FDA for the treatment of patients with locally advanced basal cell carcinoma. This article will provide an overview of the pharmacology and pharmacokinetics of sonidegib and in-depth analysis of the BOLT trial with additional data from the 12-month update. The present challenges associated with Hedgehog inhibitors will also be discussed. PMID:27189494

  3. Saving Joint with Aerosol physics

    International Nuclear Information System (INIS)

    Full text: Using electro spray method to analyze wear debris from artificial joints. Well known aerosol techniques have been applied to determine the size distribution and concentration of wear particles found in joint fluids. The organic fraction (cells and large molecules) are removed by digestion. Knowing these data the risk of clogging of blood vessels can be medicinally reduced. (author)

  4. Structuring managed care joint ventures.

    Science.gov (United States)

    Williams, L

    1995-08-01

    Providers that undertake joint ventures to secure managed care contracts must understand the important governance, operational, legal, and political issues involved. Careful planning in all these areas can help ensure that the joint venture will meet its goals and avoid problems such as inappropriately negotiated contracts and legal violations.

  5. 螺纹钢树脂锚杆的研究现状与趋势%Research Status-quo and Tendency of Thread-steel Resin Anchored Bolt

    Institute of Scientific and Technical Information of China (English)

    林健; 康红普

    2009-01-01

    Based on development status-quo of resin anchored bolt in Chinese collieries, this paper firstly presented current problem of thread-steel resin anchored bolt including steel quality, shape, transverse rib and interval of ribs, screw thread and components during production and use. Then, it put forward research key to anchored bolt supporting and problems which should be resolved.%针对近年来我国煤矿树脂锚杆发展现状,指出了目前高强度螺纹钢锚杆钢材质量、外形、横肋及肋间距、尾部螺纹及配套构件在生产及使用过程中存在的问题,并提出今后锚杆支护重点的研究方向和应解决的问题.

  6. Development and application of new-type recyclable resin metal bolts%新型可回收树脂金属锚杆的研制与应用

    Institute of Scientific and Technical Information of China (English)

    吴锐; 徐金海; 周保精; 王强

    2011-01-01

    新型可回收树脂金属锚杆弥补了普通树脂锚固式锚杆安装后难拆除的缺陷.经力学性能试验和现场应用,该锚杆具有适应性强、承载力大、可靠性高、综合力学性能好等多项优点,能够满足回采巷道支护的要求.%The new-type recyclable resin metal bolt overcomes the fault that the ordinary resin anchored bolt is difficult to remove once installed The mechanical tests and field applications show that the new-type bolt has strong adaptability, large carrying capacity, high reliability and excellent complex mechanical properties, as well as meets the supporting requirements in mining laneways.

  7. 我国蒜薹产业2010年回顾和2011年展望%2011 Review and 2010 Outlook of Garlic Bolt Industry in China

    Institute of Scientific and Technical Information of China (English)

    马岩松; 孙广智; 宋茂树; 杜孟学

    2011-01-01

    The article reviewed acquisition price,storage and sales status of garlic bolts in main producing areas of China in 2010,analysed the main factors and problems which affect operating conditions of our garlic bolt industry such as climate, the vegetable market and garlic planting, and looked forward to the development prospects of garlic bolt industry in 2011.%从2010年全国各主产区蒜薹收购价格比较及收贮与销售蒜薹情况的回顾,分析了气候、蔬菜市场、大蒜种植等影响我国蒜薹产业经营状况的主要因素及存在的问题,展望了2011年蒜薹产业的发展前景.

  8. Numerical simulation and structural parameter analysis of pushing bolt preload connection%顶推螺栓预紧连接数值模拟及结构参数影响分析

    Institute of Scientific and Technical Information of China (English)

    李占山; 程可; 陆晓峰

    2014-01-01

    Aiming at the situation that the preload of large-sized bolt is difficult to control and the stress concentration at the bottom of the thread is serious,which may cause crack and connection failure,the pushing bolt preload connection was introduced in-to the large-scale and high-load critical devices.In this paper,three-dimensional numerical simulation of a pushing bolt preload con-nection was conducted by means of finite element software ABAQUS,the stress distribution of each connecting component was stud-ied and also compared with the common bolt connection,and the influences of the pushing bolt circle diameter and pitch on the con-nection structural stress were analyzed.The result shows that the pre-tightening connection makes the maximum stress decrease by 50% at the bottom of the first thread in main bolt,and with the increase of overall stress of the round nut, the inhomogeneity of thread bottom stress along the axial is reduced by 30% ,the stress concentration is greatly improved;the main bolt thread root stress will be reduced by decreasing the concentric circle diameter of the pushing bolt,but it will cause nut stress increase, while the effect on pushing bolt stress is not significant;the nut stress will be decreased slightly with the increment of the pushing bolt pitch,the maximum stress at the bottom of main bolt thread also increase slightly,when the pushing bolt pitch is 1.5 mm,the thread stress is the minimum.%针对大规格螺栓预紧力难以控制、螺纹根部应力集中严重,极易形成裂纹而造成连接失效的现状,顶推螺栓预紧连接方式逐渐被引入高负荷的大型关键设备中。该文利用有限元软件ABAQUS对一顶推螺栓预紧连接进行了三维数值模拟,研究了各连接元件的应力分布并和普通螺栓预紧连接进行了对比,分析了顶推螺栓中心圆直径及其螺距对连接结构应力的影响。结果表明,此预紧连接使主螺栓第1道

  9. 37 CFR 1.45 - Joint inventors.

    Science.gov (United States)

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Joint inventors. 1.45 Section... Patent § 1.45 Joint inventors. (a) Joint inventors must apply for a patent jointly and each must make the... patent for an invention invented by them jointly, except as provided in § 1.47. (b) Inventors may...

  10. Low-Friction, Low-Profile, High-Moment Two-Axis Joint

    Science.gov (United States)

    Lewis, James L.; Le, Thang; Carroll, Monty B.

    2010-01-01

    The two-axis joint is a mechanical device that provides two-degrees-of-freedom motion between connected components. A compact, moment-resistant, two-axis joint is used to connect an electromechanical actuator to its driven structural members. Due to the requirements of the overall mechanism, the joint has a low profile to fit within the allowable space, low friction, and high moment-reacting capability. The mechanical arrangement of this joint can withstand high moments when loads are applied. These features allow the joint to be used in tight spaces where a high load capability is required, as well as in applications where penetrating the mounting surface is not an option or where surface mounting is required. The joint consists of one base, one clevis, one cap, two needle bearings, and a circular shim. The base of the joint is the housing (the base and the cap together), and is connected to the grounding structure via fasteners and a bolt pattern. Captive within the housing, between the base and the cap, are the rotating clevis and the needle bearings. The clevis is attached to the mechanical system (linear actuator) via a pin. This pin, and the rotational movement of the clevis with respect to the housing, provides two rotational degrees of freedom. The larger diameter flange of the clevis is sandwiched between a pair of needle bearings, one on each side of the flange. During the assembly of the two-axis joint, the circular shims are used to adjust the amount of preload that is applied to the needle bearings. The above arrangement enables the joint to handle high moments with minimal friction. To achieve the high-moment capability within a low-profile joint, the use of depth of engagement (like that of a conventional rotating shaft) to react moment is replaced with planar engagement parallel to the mounting surface. The needle bearings with the clevis flange provide the surface area to react the clevis loads/moments into the joint housing while providing minimal

  11. 某电厂节理岩质边坡抗震稳定验算%Checking of Seismic Stability of Jointed Rock Slope in a Power Plant

    Institute of Scientific and Technical Information of China (English)

    曾伟雄; 刘伟

    2014-01-01

    本文采用三维离散元数值分析软件分析了岩质高边坡稳定性。结果表明,三维离散元法可以较好地模拟岩质边坡节理分布、楔形体滑动及岩块崩落的过程。采用锚杆对破碎岩体进行加固后,能满足抗震的稳定要求,锚杆受力合理。%This paper applied the three-dimensional discrete element numerical analysis software to analyze the stability of high rock slope. The results showed that, the 3D discrete elem-ent method can bet er simulate the distribution of jointed rock slopes, wedge sliding and the process of rock block caving. The reinforcement of broken rock by sing bolt can meet the seismic stability requirements and the stress of bolt is reaso-nable.

  12. General joint hypermobility and temporomandibular joint derangement in adolescents.

    OpenAIRE

    Westling, L; Mattiasson, A.

    1992-01-01

    Joint mobility was assessed in each member of an epidemiological sample of 96 girls and 97 boys, 17 years old, and graded by means of the hypermobility score of Beighton et al. Twenty two per cent of the girls and 3% of the boys could perform five or more of the nine manoeuvres. The prevalence of symptoms and signs of internal derangement in the temporomandibular joint was higher in adolescents with hypermobility of joints (score greater than or equal to 5/9). In subjects with a high mobility...

  13. Theoretical and experimental research on the vibration characteristics excited at the end of pre-stressed rock-bolt%预应力锚杆端部受激振动特性的理论与实验研究

    Institute of Scientific and Technical Information of China (English)

    李青锋; 朱川曲

    2015-01-01

    In order to improve the random and non-destructive dynamic detection accuracy of pre-stress of rock-bolt, according to pre-stressed rock-bolt mechanical characteristics loaded on the sur-rounding rock, the mechanical model of non-destructive dynamic detection of pre-stress of rock-bolt has been firstly put forward. Secondly, based on elastic dynamics and structural dynamics, the theoretical analysis of vibration mechanical model of pre-stressed rock-bolt has been presented when it is stimu-lated at its outer end, and the pre-stress formula of pre-stressed rock-bolt has been obtained. Finally, with the simulation of surrounding rock with concrete block, and anchored resin rock-bolt in the re-served hole of concrete block, the non-prestressed and prestressed rock-bolt have been detected by non-destructive dynamic detection instrument. The result has shown that the cantilever dynamics model is consistent with vibration mechanics characteristics of pre-stressed rock-bolt when stimulated at its outer end, and that test error basically meets the requirement of the field.%为了提高预应力锚杆预应力的随机、无损动力检测精度,首先根据预应力锚杆对围岩的加载力学特点,提出了预应力锚杆的预应力无损动力检测力学模型;然后基于弹性动力学和结构动力学对预应力锚杆外端受激振动力学模型进行理论分析,得到了预应力锚杆的预应力计算式;最后以混凝土试块模拟围岩,并在混凝土试块预留孔中锚固了树脂锚杆,采用动力测试仪对无预应力和有预应力锚杆进行无损动力测试。结果表明,悬臂梁式动力学模型符合预应力锚杆外端受激振动力学特点,测试误差基本满足现场要求。

  14. Failure Anaylsis of Bolt Cracking in Pressure Gauge of Liquid Chlorine Tank%液氯储罐压力表用螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    端震

    2011-01-01

    对液氯储罐压力表用螺栓的断裂进行了失效分析.通过对化学成分分析、断口分析和金相检验,探讨了压力表用螺栓断裂的主要原因,并提出了相应的预防措施.%Failure analysis of cracking bolts was carried out. Through the analysis of macroscopic and microscopic fracture, chemical composition and microstructure, the main reasons for the bolt cracking in pressure gauge were discussed, and the preventing way was proposed.

  15. Arts-inspired students sync their assets to a nuts and bolts world: A career mentoring pilot progam

    Science.gov (United States)

    Hudson, Lynn

    This research examined how students who are arts-inspired feel about their futures in a STEM-based work climate. Science, Technology, Engineering, and Math are the nuts and bolts, and in education today, the only avenue touted for our country and our students' success in this 21st century economy. This can be disconcerting to those interested in other fields, like the arts. This study was guided by the following questions in an effort to understand if our artists and arts-inspired students realize their options and importance in this 21st century climate. The pilot study was designed to help improve the students' perception of their abilities or self-efficacy in the STEM areas by introducing STEM professionals as mentors who designed hands-on activities that simulate work in the STEM fields. Research Questions: 1. Do arts-inspired students have an interest in a STEM career area prior to participating in the career mentoring program? 2. Does participation in a STEM career mentoring program improve student's self-efficacy in STEM fields? 3. Does participation in STEM career mentoring program increase student's interest in pursuing STEM-related careers? Lent, Brown and Hackett's Social Cognitive Career Theory and Daniel Pink's, "A Whole New Mind: Why Left-Brainers Will Rule the Future" were used as the theoretical framework for this study. Seventeen African-American girls who were enrolled in the "I AM COMPLETE" summer program participated in the pilot study. Data was collected from the College Foundation of North Carolina Career Interest Explorer and the STEM Career Interest Survey, which served as a pre and post-test. This pilot offered limited support for the hypothesis, however, career mentoring and opportunities for young people to experience careers, especially in the STEM areas must continue to grow. The role that the arts play in this process is pivotal in galvanizing females and minorities to join these professions. It is the hope of this researcher that the

  16. 复合材料小尺寸螺栓的成型工艺方法探讨%Discussion on Molding Process of Smallsize Composite Bolts

    Institute of Scientific and Technical Information of China (English)

    孙博

    2014-01-01

    复合材料螺栓已经广泛应用到汽车、航天、航空等各个领域,其中小尺寸螺栓的热塑性注塑工艺成型方法也比较成熟,但热固性模压工艺成型的方法还处于研究阶段,本文通过对热塑性注塑成型的工艺方法和热固性模压成型的工艺方法的对比,阐明热固性模压成型的工艺方法的优、劣势,并对热固性模压成型的工艺方法进行分析和探讨。%Composite bolts are widely used in the fields of automobiles ,aerospace ,aviation and so on .Thermoplastic in-fusion process for smallsize bolts is mature ,but thermosetting mould pressing is still in research .In this paper ,by the com-parison of the two processes ,the advantages and disadvantages of the thermosetting mould pressing are illustrated ; mean-while,the thermosetting mould pressing is also analyzed and discussed .

  17. TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND TEMPOROMANDIBULAR-JOINT HYPERMOBILITY

    NARCIS (Netherlands)

    DIJKSTRA, PU; DEBONT, LGM; DELEEUW, R; STEGENGA, B; BOERING, G

    1993-01-01

    For studying the relationship between condylar hypermobility of the temporomandibular joint (TMJ) and osteoarthrosis (OA), 13 patients with bilateral condylar hypermobility were evaluated clinically and radiographically, 30 years after non-surgical treatment. The evaluation included range of motion,

  18. Design/Analysis of Metal/Composite Bonded Joints for Survivability at Cryogenic Temperatures

    Science.gov (United States)

    Bartoszyk, Andrew E.

    2004-01-01

    A major design and analysis challenge for the JWST ISM structure is the metal/composite bonded joints that will be required to survive down to an operational ultra-low temperature of 30K (-405 F). The initial and current baseline design for the plug-type joint consists of a titanium thin walled fitting (1-3mm thick) bonded to the interior surface of an M555/954-6 composite truss square tube with an axially stiff biased lay-up. Metallic fittings are required at various nodes of the truss structure to accommodate instrument and lift-point bolted interfaces. Analytical experience and design work done on metal/composite bonded joints at temperatures below liquid nitrogen are limited and important analysis tools, material properties, and failure criteria for composites at cryogenic temperatures are virtually nonexistent. Increasing the challenge is the difficulty in testing for these required tools and parameters at 30K. A preliminary finite element analysis shows that failure due to CTE mismatch between the biased composite and titanium or aluminum is likely. Failure is less likely with Invar, however an initial mass estimate of Invar fittings demonstrates that Invar is not an automatic alternative. In order to gain confidence in analyzing and designing the ISM joints, a comprehensive joint development testing program has been planned and is currently running. The test program is designed for the correlation of the analysis methodology, including tuning finite element model parameters, and developing a composite failure criterion for the effect of multi-axial composite stresses on the strength of a bonded joint at 30K. The testing program will also consider stress mitigation using compliant composite layers and potential strength degradation due to multiple thermal cycles. Not only will the finite element analysis be correlated to the test data, but the FEA will be used to guide the design of the test. The first phase of the test program has been completed and the

  19. Joint ventures in health care.

    Science.gov (United States)

    Pelfrey, S; Theisen, B A

    1989-04-01

    To remain competitive, many not-for-profit hospitals have turned to joint ventures with for-profit and other not-for-profit entities. The authors examine the organizational structures that are used most often to form joint ventures (contractual agreements, subsidiary corporations, partnerships, and not-for-profit title-holding corporations), as well as the advantages and disadvantages associated with each form. Nurse executives must be aware of the opportunities that joint ventures provide their institutions. These arrangements can help improve and expand services and profitability.

  20. Development of rock bolt grout and shotcrete for rock support and corrosion of steel in low-pH cementitious materials

    International Nuclear Information System (INIS)

    It is foreseen that cementitious products will be utilized in the construction of the final repository. The use of conventional cementitious material creates pulses in the magnitude of pH 12.13 in the leachates and release alkalis. Such a high pH is detrimental mainly to impairment of bentonite functioning, but also to possibly enhanced dissolution of spent fuel and alteration of fracture filling materials. It also complicates the safety analysis of the repository, as the effect of a high pH-plume should be considered in the evaluation. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis, although limiting the amount of low-pH cement is recommended. In earlier studies it was found that shotcreting, standard casting and rock bolting with low-pH cement (pH . 11 in the leachate) should be possible without any major development work. This report summarizes the results of development work done during 2008 and 2009 in the fields of low-pH rock bolt grout, low-pH shotcrete and steel corrosion in low-pH concrete. Development of low-pH rock bolt grout mixes and laboratory testing of the selected grout was followed by installation of twenty rock bolts for rock support at Aspo HRL using the chosen low-pH grout. The operation was successful and the bolts and grout are subject to follow up the next ten years. Low-pH shotcrete for rock support was initially developed within the ESDRED project, which was an Integrated Project within the European Commission sixth framework for research and technological development. ESDRED is an abbreviation for Engineering Studies and Demonstrations of Repository Designs. ESDRED was executed from 1st February 2004 to 31st January 2009. The development of the mix design described in this report was based on the results from ESDRED. After laboratory testing of the chosen mix, it was field tested in niche NASA 0408A at Aspo HRL. Further, some areas in the TASS-tunnel were

  1. Development of rock bolt grout and shotcrete for rock support and corrosion of steel in low-pH cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Boden, Anders (Vattenfall Power Consultant AB, Vaellingby (Sweden)); Pettersson, Stig (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2011-04-15

    It is foreseen that cementitious products will be utilized in the construction of the final repository. The use of conventional cementitious material creates pulses in the magnitude of pH 12.13 in the leachates and release alkalis. Such a high pH is detrimental mainly to impairment of bentonite functioning, but also to possibly enhanced dissolution of spent fuel and alteration of fracture filling materials. It also complicates the safety analysis of the repository, as the effect of a high pH-plume should be considered in the evaluation. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis, although limiting the amount of low-pH cement is recommended. In earlier studies it was found that shotcreting, standard casting and rock bolting with low-pH cement (pH . 11 in the leachate) should be possible without any major development work. This report summarizes the results of development work done during 2008 and 2009 in the fields of low-pH rock bolt grout, low-pH shotcrete and steel corrosion in low-pH concrete. Development of low-pH rock bolt grout mixes and laboratory testing of the selected grout was followed by installation of twenty rock bolts for rock support at Aspo HRL using the chosen low-pH grout. The operation was successful and the bolts and grout are subject to follow up the next ten years. Low-pH shotcrete for rock support was initially developed within the ESDRED project, which was an Integrated Project within the European Commission sixth framework for research and technological development. ESDRED is an abbreviation for Engineering Studies and Demonstrations of Repository Designs. ESDRED was executed from 1st February 2004 to 31st January 2009. The development of the mix design described in this report was based on the results from ESDRED. After laboratory testing of the chosen mix, it was field tested in niche NASA 0408A at Aspo HRL. Further, some areas in the TASS-tunnel were

  2. US Joint Ventures 2014 revision

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A joint venture is a self-directed partnership of agencies, organizations, corporations, tribes, or individuals that has formally accepted the responsibility of...

  3. Joint Performance and Planning System

    Data.gov (United States)

    US Agency for International Development — A joint State/USAID system hosted by State that integrates resource and performance information at the program level and enables more flexible and frequent entry of...

  4. Campus/Industry Joint Ventures.

    Science.gov (United States)

    McDonald, Eugene J.

    1985-01-01

    Opportunities for joint economic ventures of colleges and industry are discussed, and a variety of ventures undertaken by Duke University are outlined, including a health club, hotel, and office building. Tax and financing considerations are noted. (MSE)

  5. Joint audits - benefit or burden?

    DEFF Research Database (Denmark)

    Holm, Claus; Thinggaard, Frank

    In this paper we examine whether there are perceived and observed benefits or burdens from using two audit firms instead of one. In 2005 the mandatory joint audit requirement was abolished in Denmark. This provides a unique setting for studying the consequences and implications of going from...... a joint audit regime to a single auditor/voluntary joint audit regime. The dataset used in this paper has been collected for the full population of non-financial Danish companies listed on the Copenhagen Stock Exchange (CSE) in the years 2004 and 2005. We find that a majority of firms perceive joint...... driving-force behind this seems to be initial price cuts due to competition. However, the results indicate that efficiency gains may also be part of the explanation. We do not find either a general or marginal Big Four effect in the Danish audit market....

  6. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  7. Finishing touch to joint venture

    CERN Multimedia

    2003-01-01

    "A new process for polishing titanium and its alloys has been announced following an agreement between Bripol (an Anopol/Delmet joint venture) of Birmingham and the European Organisation for Nuclear Reseach (CERN) in Geneva" (1 paragraph).

  8. IRS memorandum limits joint ventures.

    Science.gov (United States)

    Herman, A W

    1992-08-01

    Based on a new memorandum, the Internal Revenue Service (IRS) will be looking at joint hospital/physician activities with greater attention to the nuances of public versus private benefit. As a result, hospitals face greater risk of losing their tax-exempt status in the maze of joint ventures, physician recruitment, and practice acquisition. To be successful, ventures will have to be backed by sound reasoning and thorough documentation.

  9. "Fraud alert": joint venture arrangements.

    Science.gov (United States)

    Vipperman, R M

    1989-01-01

    The Office of Inspector General of the Department of Health and Human Services recently issued a special "Fraud Alert" identifying those characteristics of joint venture arrangements that it views as indicators of potentially unlawful activity. As discussed in this article, participants in joint ventures should examine their arrangements to see if one or more of the questionable features are present, and, if so, should take steps to eliminate them, to the extent possible.

  10. Joint probabilities and quantum cognition

    CERN Document Server

    de Barros, J Acacio

    2012-01-01

    In this paper we discuss the existence of joint probability distributions for quantum-like response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

  11. 基于图像识别技术的螺栓裂缝识别系统研究%The Research of Bolt Cracks Discern System based on Image Recognition Technology

    Institute of Scientific and Technical Information of China (English)

    李亚琳; 王玉增; 李柏震; 刘双源

    2013-01-01

    提出了一种基于图像识别技术的螺栓裂缝非接触识别技术.利用高精度工业相机对待检螺栓进行拍摄,然后采用细化、提高曝光度、图像分割等技术对拍摄到的图片进行处理,获取图像特征,最终达到识别裂缝的目的.实验表明,将图像识别技术应用于螺栓裂缝识别领域,可以大大简化识别步骤,提高识别精度,为螺栓裂缝检测提供了新的发展方向.%Propose a non-contact identification of bolt crack based on image recognition technology. Take photo of every bolt waiting for the detection with high-precision industrial cameras, then process the photos with image thinning, improve exposure, edge detection technology, so we can get the image feature, and finally achieve the purpose of crack identification. The experiment shows that the use of image recognition technology in bolt cracks identification can greatly simplify the identification step, improving recognition accuracy, and provides a new direction of development for the bolt cracks detection.

  12. Failure Analysis on 12.9 Grade Hex Head Bolt of Mine Car Brake%12.9级矿车制动盘螺栓断裂失效分析

    Institute of Scientific and Technical Information of China (English)

    姜招喜

    2014-01-01

    The 12.9 grade hex head bolts,made of SCM435 steel,fractured after being installed and laid up for 42 h.The chemical composition analysis,macro-and micro-analysises of the fractured bolt were performed by using photoelectric direct-reading spectrograph,OM,SEM and hydrogen tester to reveal cause of the bolt fracture.The results show that the bolt fracture is a hydrogen-assisted delayed cracking.%材料为SCM435钢的12.9级六角头螺栓服役42 h后发生断裂。为了揭示螺栓断裂的原因,采用光电直读光谱仪、光学显微镜、扫描电镜和测氢仪对断裂的螺栓进行了化学成分、宏观和微观等分析。研究结果表明,螺栓断裂是氢致延迟断裂。

  13. Numerical simulation optimization research of bolt profile configuration with resin full-length anchoring%树脂全长锚固锚杆外形尺寸优化数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    林健; 任硕

    2015-01-01

    锚杆全长预应力锚固支护方式是解决复杂困难巷道支护的有效手段,但是由于施工困难,一直制约着它的应用与推广。本文致力于通过优化锚杆外形的方法,在保证锚杆锚固性能前提下,解决煤矿巷道全长锚固施工困难的问题。论文采用数值模拟的方法,对锚杆外形与锚杆锚固性能之间的关系进行了研究,提出锚杆外形相关参数的合理值。优化后的锚杆横肋高度由原来的1.46 mm降低为1.20 mm,横肋间距由原来的11 mm增加到30 mm,横肋宽度由3 mm增加到10 mm。优化后的锚杆在锚固性能不降低的情况下,搅拌阻力降低50%左右,搅拌效果理想,达到了优化的目的。%Bolting with resin full-length anchor and high prestress is an effective means to solve sup-port problem of complex and difficult roadway, but its application and promotion have always been re-stricted due to the construction difficulties. This paper is committed to solving the difficult problem of coal mine roadway full-length anchoring through optimized anchor shape under the premise of the guarantee of anchor performance. The numerical simulation methods have been used to research the re-lationship between the bolt shape and anchorage bolt performance. Optimized bolt cross rib height is reduced from 1.46 mm to 1.20 mm;bolt cross rib spacing is increased from 11 mm to 30 mm;and the bolt cross rib width is increased from 3 mm to 10 mm. The optimized bolt shearing resistance is reduced by about 50%under the condition of not reducing in the anchorage performance. Consequently, mixing effect is ideal, achieving the goal of the optimization.

  14. 12 CFR 347.107 - Joint ventures.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Joint ventures. 347.107 Section 347.107 Banks... INTERNATIONAL BANKING § 347.107 Joint ventures. (a) Joint ventures. If a bank, directly or indirectly, acquires or holds an equity interest in a foreign organization that is a joint venture, and the bank or...

  15. Condylar hyperplasia following unilateral temporomandibular joint replacement.

    Science.gov (United States)

    Machon, V; Levorova, J; Hirjak, D; Foltan, R

    2015-06-01

    Total joint replacement of the temporomandibular joint (TJR) can be associated with intraoperative and postoperative complications. We report herein the occurrence of a postoperative open bite malocclusion, the result of condylar hyperplasia affecting the non-operated joint at 1 year after unilateral total joint replacement. PMID:25662429

  16. Management of acromioclavicular joint injuries.

    Science.gov (United States)

    Li, Xinning; Ma, Richard; Bedi, Asheesh; Dines, David M; Altchek, David W; Dines, Joshua S

    2014-01-01

    Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these

  17. Migrating bone shards in dissecting Charcot joints.

    Science.gov (United States)

    Forrester, D M; Magre, G

    1978-06-01

    Extensive periarticular calcification is characteristic of Charcot joints. Fragmentation of the articular margins of bone contributes to the bony detritus, but the majority forms de novo in the joint capsule. Occasionally the calcific debris is seen far removed from the joint. Dissection of a chronically distended joint along muscle planes is most commonly associated with the inflammatory joint disease of rheumatoid arthritis. Its occurrence in Charcot joints is documented by arthrography, which demonstrates continuity of the joint space and the distant calcifications. PMID:418652

  18. Elastic stress distributions: axial and shear stress distributions in an anchor bolt during a pullout test%弹性拉拔中锚杆轴力和剪力分布力学计算

    Institute of Scientific and Technical Information of China (English)

    刘建庄; 张农; 韩昌良

    2012-01-01

    Planar and 3-D mechanical models were used to test rock-bolt pull out. The results were used to derive formulas for the axial force and bond shear stress in the bolt under elastic conditions. A new term, the decay of shear stress coefficient, is proposed that has an obvious effect on the stress distributions. Theoretical estimates of how cement or resin-anchored bolt stresses decay in sandstone rock are presented. These estimates are then compared to bolt properties in a coal body. Axial force and grout shear stress in soft rock are found to be distrib- uted along the entire length of the bolt. However, in hard rock the axial force decays rapidly, dropping by 95 percent along 80 to 100 cm in the grout. The grout shear stress decays to 0.06 MPa within about 40 to 50 cm in the grout.%通过构建平面和三维力学模型,推导了弹性状态下沿杆长方向轴力和黏结剪应力的分布函数,提出了锚杆剪应力衰减系数的概念,并给出了力学算式;对比分析了围岩为砂岩和煤体时,水泥锚固和树脂锚固两种情况下,锚杆轴力和剪力的衰减特征.结果表明:软岩锚固中轴力和剪力为全长分布型,硬岩0.8-1.0m左右即衰减为拉拔力的5%,黏结剪应力的主要作用范围为0-0.5m,在0.4-0.5m处衰减为0.06MPa左右.

  19. Experimental Study on a New Bolt Connection Used in Multistory Fabricated Steel Structure%多层预拼装钢结构系统特殊连接螺栓性能试验研究

    Institute of Scientific and Technical Information of China (English)

    丁娟; 张其林; 张齐; 陈国栋; 杨彬

    2014-01-01

    A new kind of bolt connection consisted of self-tapping steel plate and high strength bolt will be used in a multistory fabricated steel structure system.But there are no regulations on such kind of bolted con-nection.Therefore,extensive experimental research on bolted connection was taken.The objective of the re-search was to determine the ductility and resistance of such connection.Different failure modes of bolted con-nections could be observed in the test.The ultimate bearing capacity was compared with that predicted by the current connection provisions specified in Chinese steel design standards.Besides a pretension experience was put,which demonstrates that this new kind of connection can satisfy the requirement of Chinese steel design code on pretension.%某新型多层预拼装钢结构系统采用了钢板自攻螺纹螺栓连接形式,非现行规范中的连接类型,需完成相关试验进行论证。针对工程常用6种规格高强螺栓自攻螺纹连接进行了单向拉伸试验,研究了两种破坏模式,并将极限承载力与规范要求承载力设计值与预紧力进行比对,并且对 M20(8.8S)螺栓进行预紧力时变效应测试,研究表明,此种连接类型在使用过程中可以保持一定的预紧力水平。

  20. Experimental and numerical analysis of clamped joints in front motorbike suspensions

    Directory of Open Access Journals (Sweden)

    Vincenzi N.

    2010-06-01

    Full Text Available Clamped joints are shaft-hub connections used, as an instance, in front motorbike suspensions to lock the steering plates with the legs and the legs with the wheel pin, by means of one or two bolts. The preloading force, produced during the tightening process, should be evaluated accurately, since it must lock safely the shaft, without overcoming the yielding point of the hub. Firstly, friction coefficients have been evaluated on “ad-hoc designed” specimens, by applying the Design of Experiment approach: the applied tightening torque has been precisely related to the imposed preloading force. Then, the tensile state of clamps have been evaluated both via FEM and by leveraging some design formulae proposed by the Authors as function of the preloading force and of the clamp geometry. Finally, the results have been compared to those given by some strain gauges applied on the tested clamps: the discrepancies between numerical analyses, the design formulae and the experimental results remains under a threshold of 10%.