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Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sliding contact between wheel and rail will occur when the train is starting, braking, or passing through curved tracks and long-heavy down grades. In subways, the sliding contact is more frequent. The wear caused by sliding contact has a significant effect on the stress and friction heat of contact region. According to the numerical calculation method and friction heat transfer theory, a wheel-rail contact wear model and a friction heat transfer model are established. The wear-dependent contact stress is introduced, and a moving heat source is employed to simulate the friction heat. The temperature-dependent material parameters are adopted in models. The influences of wear on stress and temperature are studied. The results show that, with the increase of sliding distance, the wheel-rail contact patch becomes larger, the shape of contact patch changes from convex to flat, the maximum contact stress descends gradually, and the distribution of contact stress tends to be uniform. When the wear depth of wheel exceeds 0.2 mm, the node temperature values calculated by the initial contact stress are higher than those calculated by the wear-dependent contact stress. And as the sliding distance increases, the difference in temperatures increases gradually. At the end of sliding contact, the maximum temperatures of wheel and rail calculated by the initial contact stress are 113. 9 °C and 61.0 °C respectively higher than those obtained by the wear-dependent contact stress. The research results indicate that the wear obviously influences the contact stress and friction heat, and these influences should be fully considered when calculating the stress and friction heat. [ABSTRACT FROM AUTHOR]

To study the thermal ‐ force bulging behavior of roll profile electromagnetic control technology (RPECT), the variation laws of the comprehensive roll crown, the thermal ‐ force contribution roll crown and the ratio of the force crown with the heat of contact zone under different current densities and frequencies were analyzed by finite element method, and the mapping relationship and establishment condition between the heat of contact zone and the thermal‐force bulging ability were explored. The results show that, within the range of the middle and low values of the heat of contact zone, the thermal‐force control ability corresponding to the same value of the heat of contact zone cannot be affected by the magnetic parameters. Therefore, an efficient control strategy of RPECT can be proposed, which takes the heat of contact zone as the bridge value between the input parameter and the control ability. The strategy can quickly achieve the target temperature rise effect of the contact zone by increasing the magnetic parameters, and then obtain the target control ability. Taking the roll gap crown requirement of 20 μm as an example, the comparison between the original and the efficient control strategy shows that the control time of the new strategy can be effectively shortened to 19. 57% of the original control time. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The ANSYS finite element software is introduced to simulate the cooling efficiency and thermal conductivity of the internal structure of the roll to study the influence of cooling water temperature, flow rate and aluminum melt on the roll temperature field and thermal conductivity. The research results show that in the process of casting and rolling, the aluminum melt is in contact with the rolls in the casting and rolling area, where the maximum temperature of the rolls is 520 °C. The temperature of the roll is gradually reduced to 40 °C, and then the roll continues to rotate until it enters the casting and rolling area, and the cycle is repeated. The reduction of the cooling water temperature could not significantly improve the roll temperature field. The increase of the cooling water flow rate can reduce the temperature field of the cooling water channel in the roll core. The temperature of aluminum melt at the exit of the casting nozzle can significantly increase the temperature field of the roll and the rolling temperature of the aluminum melt at the center of the roll gap, but it does not affect the temperature distribution at the exit of the roll gap after the aluminum melt is cooled by the roll. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the rail corrugation phenomenon with the wavelength of 160-250mm in the steel spring floating slab track of a certain subway straight section, a rigid-flexible coupling dynamics model of the vehicle-steel spring floating slab track is established based on the finite element theory and the vehicle-track coupling dynamics theory. From the point of view of the vibration characteristics of track system and the contact characteristics of wheel and rail, the causes and mitigation measures of rail wave wear are studied by taking the rail wear power as the evaluation index. The generation of rail corrugation may be related to the transverse co-direction/reverse bending vibration modes of the rails on the left and right sides of the 8-15 order, the vertical bending mode of the track plate of the 8-9 order, and the torsional vibration mode of the track plate of the 6-8 order. Under the premise of not affecting driving safety, wear power at the rail wave wear frequency can be reduced by taking the vertical stiffness of the fastener 10~30 MN/ m, the vertical damping of the fastener more than 20 kN·s/m or the lateral damping of the fastener 30 kN·s/m, so as to slow down the development of rail wave wear. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the rapid development of wind power industry, people pay more attention to the fatigue life prediction of wind turbine components. In this paper, the contact load and maximum contact stress of double row tapered roller bearing are calculated, and the distribution law of contact load is analyzed. The maximum contact load rolling element/raceway contact model is established by using ANSYS Workbench, and the static calculation is completed. The maximum contact stress calculated by theory is compared with the maximum contact stress obtained by simulation. The stress fatigue life was predicted by n Code. The results show that the maximum contact load on the left side is greater than that on the right side, and the maximum contact load occurs at the contact between the first roller and the outer ring with zero contact angle on the left side; the error between the theoretical calculation and simulation results of the maximum contact stress is 5.7%; the error between the theoretical calculation result and the simulation analysis result is 0.69%, which verifies the correctness and feasibility of the simulation method and model Line. The maximum contact stress and the location of fatigue failure can be observed through numerical simulation analysis, which provides reference for bearing design in practical engineering, plays a role of optimization design, and has a certain guiding significance for experiments. [ABSTRACT FROM AUTHOR]

In order to overcome the shortcomings of the steel spring floating slab track structure in the urban rail transit with short sleepers in the steel spring floating slab structure due to its poor maintenance accuracy, large adjustment workload, difficulty in assembling the rail row, and slow construction progress, the optimized double-block sleepers ballastless track technology is introduced into the steel spring floating slab structure to form a new double-block sleepers floating slab structure with high precision of the double-block sleepers ballastless track and high vibration damping effect of steel spring floating slab. The static characteristics under the four conditions of lifting, stacking, hoisting and construction are analyzed and studied by a finite element model established, optimal structural design parameters are determined, the overall and local reinforcement design of the structure is carried out according to the limit state design method of partial reinforcement design, and the test section is prepared and dynamic performance test is conducted. The results show that the new double-block sleeper can effectively reduce the cracks of the ballast bed on account of its better rail bottom slope accuracy and smoothness, simple construction and fast speed; within the speed range of 80~120 km/h, the maximum derailment coefficient is 0. 52, and the maximum wheel load reduction rate is 0. 28, which are all less than the specified limits, and the vibration reduction effect reaches 14 dB; and it has good driving safety indicators and vibration reduction performance. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Wool Textile Journal is the property of National Wool Textile Science & Technology Information Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin University of Science & Technology is the property of Journal of Harbin University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The influence of nitriding treatment on wheel/rail rolling contact fatigue and surface wear behavior of CL60 wheel was studied on JD-DRCF/M rolling contact fatigue/wear tester,the wheel surface nitriding treatment on the mechanisms of wheel/rail surface damage are compared and analyzed. The results showed that the surface nitriding treatment could form a uniform and dense white layer about 3 μm ～ 5 μm thick and a diffusion layer about 20 μm thick on the wheel surface. Under the wheel surface after nitriding process,the adhesive coefficient between wheel/rail was reduced by 11. 7% in dry condition,and reduced by 18. 4% in aqueous media,but the nitriding treatment still can keep the higher adhesive coefficient between wheel/rail system,which can prevent the occurrence of the phenomenon such as wheel-slip; Nitriding treatment not only significantly improve the wear resistance on the surface of the wheel,but also effectively reduce the wear of the rail sample,the amount of damage reduced by 58. 05% and 10. 77%,respectively. In short,the nitriding on wheel for wheel/rail system can effectively reduce the wear,improve the rolling contact fatigue resistance of wheel materials. The method is applied to the actual,it can effectively improve the service life of wheel/rail system,reduce the damage of wheel/rail material under the heavy-load condition.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problems of fluffing and thread breakage of the weft due to the large peak value of the rapier acceleration,adding a roller between the kendo and the slider to improve the kinematic characteristics of spatial linkage.The influence of rolling contact on the rapier acceleration curve was analyzed. By establishing a virtual prototype of a space link weft insertion mechanism and performing kinematics analysis in ADAMS to obtain a kinematic characteristic curve, and static analysis of kendo was made. The results show that the peak value of the acceleration curve of the rapier of the weft insertion mechanism after adding the roller is reduced by 11. 11% and the stress is reduced by 36%. The kendo meets the strength requirements and the design requirements. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to diagnose the incipient fault of a rolling bearing, an approach for incipient fault diagnosis using the component-envelope detection method is presented in this paper. SVD is first used to reconstruct the one-dimensional sampling time sequence into high dimensions space. Then subspace containing fault feature information can be found. An inverse transformation is performed to change this subspace into component signal. With envelope analysis, the envelope spectrum of the component signal is obtained. Through the envelope spectrum, the incipient fault feature of rolling bearing can be detected obviously. Both simulation and engineering experimental results validate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

This paper presents a method for the fault diagnosis of rolling element bearings using the principal components analysis of the bispectrum and hidden Markov models (HMM). It has been shown that the bispectrum magnitudes and distribution characteristics are significantly different under different failure status of bearings, but much more similar for the same type of faults under different operation conditions. Thus, the bispectrum can be used as the observation quantity for HMM to detect the fault category. Then, a principal component analysis (PCA) based method is used to extract the significant components so as to reduce the dimension of the feature vector, and the number of the principal components is also determined with the eigenvalue cumulative contribution rate. Finally, we conducted a number of experiments under different operation conditions and fault severities to validate the efficiency of the proposed method. The results show that the proposed method is effective in the detection of the various bearings faults, and also robust to the variation of the operation conditions. [ABSTRACT FROM AUTHOR]

When fault arises in the rolling bearing it usually takes on cyclical characteristics. Firstly, the desired source signal is extracted coarsely and the weight separation matrix ... is obtained by the proposed algorithm using the estimated fundamental period of the desired fault signal. Then, the fixed-point algorithm is applied to the observed signals using ... as its initial weight matrix and more accurate desired source signal is derived. The proposed method has the following advantages over the constrained independent component analysis (CICA) : it neither need to estimate the fundamental period τ of the desired source accurately nor need to construct the reference signal precisely which is otherwise for the CICA method. Besides, the proposed method has a higher accuracy over the recent BSE methods. At last, the above stated advantages of the proposed method are verified through simulation and the fault diagnosis test of rolling bearings. [ABSTRACT FROM AUTHOR]

In order to improve the finishing eeficiency of pneumatic wheel for laser hardening mold, and solve the subtle crack problem of pneumatic wheel caused by high frequency vibration and prolonged pressure during the long time finishing, a composite pneumatic wheel of SBR reinforced by PPTA-pulp was designed. Through the axial tensile test of the standard sample, the stress-strain relationship and the elastic modulus of composite pneumatic wheel were received. Using ANSYS/LS-DYNA the modal and strees distribution of composite pneumatic wheel were simulated, the distribution curve of the modal frequency and contact stress were received. According to the finishing experiment of laser hardening molt!, the correctnees of the simulation was verified. The results show that the frequency of the composite pneumatic wheel has been improved significantly, and the strees distribution is uniform, so as to improve the finishing eeficiency for mold with high hardnees and wear resistance. If adding 3.3% PPTA-pulp, both the profile ability and the strees distribution would be preferable. That could be beter for the laser hardening mold finishing. [ABSTRACT FROM AUTHOR]

Fault diagnosis of the low-speed rolling bearings is difficult, due to the reasons of the special structure, the peculiar working condition and the complex fault mechanism. Due to the fault features of the low-speed rolling bearings, in this paper, by applying stress waves and wavelet analysis, a new method for the fault diagnosis of those rolling bearings was presented. Firstly, the 01B65EX Cooper rolling bearing with low speed is taken as an example, and the three-dimension contact models for the good and inner race fault bearings were set up, which is studied through finite element method, and then the stress, the strain and the contact stress distribution are then given. The stress and strain distribution law of the outer race and the contact stress distribution law of the interface on good and fault bearing were compared. Then on the basis of the stress wave analysis, the wavelet transform of data signals that are collected in the experiments are carried out, for which the db6 wavelet with 4 scales is employed. Finally the characteristic frequencies of the stress waves with the simulative faults are extracted. The fault of low-speed rolling bearing is well diagnosed. Results show that stress wave and wavelet analysis is an effective method for diagnosing the fault of low-speed machinery. [ABSTRACT FROM AUTHOR]

The fault characteristic signals of rolling bearings are in low frequency band, and the useful signals are often buried in heavy noise and difficult to be detected. Two-dimensional approximate entropy (AE2d) was proposed to measure the states of chaotic oscillator, and a method based on chaotic oscillator and AE2d was presented to diagnose rolling bearings fault. By using the characters of chaotic Oscillator being sensitive to weak periodic signal. and AE2d being effective to recognizing the change of chaotic oscillator, the fault could be identified. Diagnosis of inner and outer race fault of rolling bearing confirm the effectiveness of this method. [ABSTRACT FROM AUTHOR]