The Experts below are selected from a list of 1653 Experts worldwide ranked by ideXlab platform

Jung Seok Kim - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of structural integrity after ballast-flying impact damage of a GFRP lightweight Bogie Frame for railway vehicles
    Journal of Mechanical Science and Technology, 2015
    Co-Authors: Jun-sung Goo, Jung Seok Kim, Kwang-bok Shin
    Abstract:

    To evaluate the structural integrity of a GFRP composite Bogie Frame induced by ballast-flying phenomena under driving environments of urban trains, an experimental and numerical approach was used in this study. In the experimental approach, a low-velocity impact test and residual compression test after impact were conducted to investigate impact responses and the degradation of mechanical properties of glass fiber/epoxy 4-harness satin woven laminate composites applied to a Bogie Frame. The numerical approach was comprised of two linked phases. The impact analysis was first conducted to determine the mechanical degradation of a composite Bogie Frame due to ballast-flying impact, and then the static analysis was done to evaluate the structural integrity of the damaged composite Bogie Frame with the residual stress and strain results obtained from impact analysis. To verify the reliability of finite element models used for numerical analysis of a composite Bogie Frame, the proposed finite element models were evaluated by comparing the results of the impact test for specimens. The evaluation results of structural integrity after impact for Bogie Frame indicated that there was an insignificant effect on structural integrity by impact damage induced by the ballast flying of composite Bogie Frame. This reason is because the location of post-impact residual compression occurring on the Bogie Frame does not exert a significant influence on the load required for the structural integrity evaluation.

  • Natural frequency evaluation of a lightweight GFRP composite Bogie Frame
    International Journal of Precision Engineering and Manufacturing, 2015
    Co-Authors: Jung Seok Kim, Woo-geun Lee, Il-kyeom Kim, Hyuk-jin Yoon
    Abstract:

    A glass-fiber-reinforced plastic (GFRP) composite Bogie Frame was designed and manufactured in this study. The lightweight GFRP Bogie Frame was designed to not only sustain heavy static and dynamic loads but also have a suspension function. Therefore, its dynamic characteristics are an important factor. In this study, its natural frequency was evaluated by means of a modal test and the test results were validated using a finite element analysis. Given these experimentally obtained dynamic characteristics, the running performance of a railway vehicle equipped with the GFRP Bogie Frame was assessed. The first bending natural frequency of the composite Bogie Frame was 22.8 Hz, which corresponds to 27.7% of the steel Frame. The vehicle dynamic analysis results showed that the derailment index, dynamic wheel unloading, wheel wear index, and ride comfort satisfied the design requirements.

  • Manufacturing and testing of a GFRP composite Bogie Frame with straight side beam members
    Journal of Mechanical Science and Technology, 2013
    Co-Authors: Jung Seok Kim, Woo-geun Lee, Il-kyeom Kim
    Abstract:

    To replace a traditional steel Bogie with a composite one, this study designed and manufactured a composite Bogie Frame made of glass fiber-reinforced plastics to be applied to the Bogie of an urban subway train. To evaluate its structural behavior, the composite Bogie Frame was tested under critical load conditions encompassing vertical loads and a twisting load. The test revealed that the maximum strain measured under the vertical load corresponded to 16.3% of the failure strain of the GEP224 glass fabric/epoxy sample. According to a durability evaluation using Goodman diagrams, both the measured and the calculated stress data were within the endurance limit. Therefore, the composite Bogie Frame satisfied the structural safety requirements. The evaluation of the contribution of each load case clearly showed that the vertical and braking loads were the most critical load cases. Adding the braking load cases led to movement of the critical point from the inner joint to the outer joint due to the increased torsion.

  • A study on evaluation of fatigue strength of a GFRP composite Bogie Frame for urban subway vehicles
    Advanced Composite Materials, 2013
    Co-Authors: Kwang-woo Jeon, Kwang-bok Shin, Jung Seok Kim
    Abstract:

    The fatigue strength and life of a GFRP composite Bogie Frame for urban subway trains were evaluated in this study. The GEP224 glass fabric/epoxy was selected as the structural material of a composite Bogie Frame to save its weight. In order to obtain the fatigue characteristics of the GEP224 glass/epoxy composite material, the tension–compression fatigue test was done with three different stacking sequences of warp direction, fill direction, and warp/fill direction, respectively. A fatigue test was conducted with a stress ratio, R of 0.1 and −1, and up to endurance limit of 107 with frequency of 5 Hz. The fatigue strength of the GFRP composite Bogie Frame was evaluated on the basis of the S-N curve and Goodman diagrams obtained from GEP224 glass/epoxy composites according to the JIS E 4207 and UIC 515/615-4. The result shows that fatigue strength of the GFRP composite Bogie has satisfied the design requirements. Also, the GFRP composite Bogie Frame had a good fatigue performance in comparison with conven...

  • an evaluation of fatigue life and strength of lightweight Bogie Frame made of laminate composites
    Transactions of The Korean Society of Mechanical Engineers A, 2011
    Co-Authors: Kwang-woo Jeon, Kwang-bok Shin, Jung Seok Kim
    Abstract:

    We describe the evaluation of the fatigue life and strength of a lightweight railway Bogie Frame made of glass fiber/epoxy 4-harness satin-woven composites. To obtain the S-N curve for the evaluation of the fatigue characteristics of the composite Bogie Frame, we performed a tension-compression fatigue test for composite specimens with different stacking sequences of the warp direction, fill direction, and 0°/90° direction. We used a stress ratio (R) of -1, a frequency of 5 Hz, and an endurance limit of 10 7 . The fatigue strength of the composite Bogie Frame was evaluated by a Goodman diagram according to JIS E 4207. The results show that the fatigue life and strength of the lightweight composite Bogie satisfy the requirements of JIS E 4207. Given its weight, its performance was better than that of a conventional metal Bogie Frame based on an SM490A steel material.

Shou-guang Sun - One of the best experts on this subject based on the ideXlab platform.

  • An investigation into the fatigue failure of metro vehicle Bogie Frame
    Engineering Failure Analysis, 2020
    Co-Authors: Binjie Wang, Shou-guang Sun, Shuqiang Xie, Chaoyong Jiang, Qingwei Song, Xi Wang
    Abstract:

    Abstract Metro vehicle Bogie Frame is usually subjected to complex external excitations. The fatigue damage accumulation of Bogie Frame is induced by multiple elements and may even lead to failure hazard. Therefore, a comprehensive investigation into the influencing elements was conducted in this paper. To achieve this purpose, a targeted field test was first carried out under normal operating conditions to obtain the dynamic stress and operating state data. Then, P2 resonance frequency of vehicle-track system was calculated, and rail corrugation and 8th order wheel polygon were determined. Damage analysis was performed for rail corrugation, wheel polygon, rail joint, velocity, and passenger capacity. The results indicate that rail corrugation accompanied with wheel polygon are the main reasons for the damage of Bogie Frame. This research will be beneficial for ensuring operation safety and developing reasonable maintenance schedule for metro vehicle.

  • Improving the fatigue reliability of metro vehicle Bogie Frame based on load spectrum
    International Journal of Fatigue, 2020
    Co-Authors: Binjie Wang, Ren Zunsong, Shou-guang Sun
    Abstract:

    Abstract Fatigue cracks, which occur at the junctions between key brackets and the transverse beam of the metro Bogie Frame, significantly affect the operating safety of the vehicle. Since the load inputs in the design specifications used for Bogie Frame cannot fully address the actual operating conditions, it indicates that the fatigue reliability of Bogie Frames in actual operation is critically inadequate. In the event of this problem, a high-precision dynamometric Frame was developed to conduct long-term on-track test to obtain real loading conditions and damage at the fatigue control locations. Taking the discrepancy between the measured fatigue damage and the calculated damage as the objective function, the damage consistency-based load spectrum was established and the damage of the Frame under the operating condition was reproduced. Finally, fatigue reliability improvement of the Bogie Frame was systematically and comprehensively achieved.

  • Strength Evaluation of a Bogie Frame by Different Methods
    Mechanical Engineering Science, 2019
    Co-Authors: Daoyun Chen, Shou-guang Sun
    Abstract:

    Some crucial loads that current strength design specifications have not taken into ac-count are also considered when assessing the strength of a Bogie Frame. Calculation methods of these loads come from load analysis. Finite element simulation and fa-tigue test rig have been used to assess static strength and fatigue strength of a Bogie Frame. In addition to the two methods, actual running test is also used to assess Bogie Frame fatigue strength. In finite element simulation method, endurance limit and modified Goodman fatigue limit diagram are two important tools to judge whether fatigue strength of a Bogie Frame meets requirement. In actual running test method, Miner linear cumulative damage rule is used to assess Bogie Frame fatigue strength. Endurance limit and modified Goodman fatigue limit diagram are two effective tools to judge fatigue strength of the Frame. For the measured dynamic stress data, Miner linear cumulative damage rule seems to be very effective when judging fatigue strength of the Frame. All the above methods have proved that static and fatigue strength of the tested Bogie Frame meets requirement.

  • Analysis of the Load-Stress Response Characteristics of the Bogie Frame in Intercity Electric Multiple Unit
    Chinese Journal of Mechanical Engineering, 2018
    Co-Authors: Hua Zou, Shou-guang Sun, Ren Zunsong
    Abstract:

    Load spectra research for Bogie Frame requires establishing the load-stress relationship on working condition, which has been omitted by the researchers. With the load-stress of the Bogie Frame of an intercity Electric Multiple Unit (Hereinafter referred to as EMU) as the research object, an optimization model of the load-stress transfer relationship is established. The load-stress coefficient for EMU Bogie Frame was calibrated in the laboratory bench and online test was arranged on Dazhou-Chengdu line. Comparison of nonlinear and linear neural networks proves that the linear transitive relation between the load and stress of the Bogie Frame in the operating process is highly suitable. An optimization model of the load-stress transfer coefficient is obtained. The data calculated with the modified coefficient are closer to the dynamic stress results in the actual operating process than the data calculated with the calibration coefficient. The coefficient of the modified transitive relation is unaffected by operating area, empty load, heavy load, or other conditions in the operating process of the intercity EMU. The real loads in actual situations are obtained. The model of online load-stress relationship that is highly suitable for line stress calculation is finally established. The research is helpful for further damage calculation and inferring the time history signal of the load in load spectra research.

  • Theoretical research and experimental validation of elastic dynamic load spectra on Bogie Frame of high-speed train
    Chinese Journal of Mechanical Engineering, 2016
    Co-Authors: Ning Zhu, Shou-guang Sun, Hua Zou
    Abstract:

    When a train runs at high speeds, the external exciting frequencies approach the natural frequencies of Bogie critical components, thereby inducing strong elastic vibrations. The present international reliability test evaluation standard and design criteria of Bogie Frames are all based on the quasi-static deformation hypothesis. Structural fatigue damage generated by structural elastic vibrations has not yet been included. In this paper, theoretical research and experimental validation are done on elastic dynamic load spectra on Bogie Frame of high-speed train. The construction of the load series that correspond to elastic dynamic deformation modes is studied. The simplified form of the load series is obtained. A theory of simplified dynamic load–time histories is then deduced. Measured data from the Beijing–Shanghai Dedicated Passenger Line are introduced to derive the simplified dynamic load–time histories. The simplified dynamic discrete load spectra of Bogie Frame are established. Based on the damage consistency criterion and a genetic algorithm, damage consistency calibration of the simplified dynamic load spectra is finally performed. The computed result proves that the simplified load series is reasonable. The calibrated damage that corresponds to the elastic dynamic discrete load spectra can cover the actual damage at the operating conditions. The calibrated damage satisfies the safety requirement of damage consistency criterion for Bogie Frame. This research is helpful for investigating the standardized load spectra of Bogie Frame of high-speed train.

Jing Zeng - One of the best experts on this subject based on the ideXlab platform.

  • fatigue life reliability evaluation in a high speed train Bogie Frame using accelerated life and numerical test
    Reliability Engineering & System Safety, 2019
    Co-Authors: Heyan Zheng, Jing Zeng, Tianli Chen
    Abstract:

    Abstract Durability fatigue tests for full-scale structures are essential to ensure the fatigue reliability and operational safety of high-speed trains. An accelerated life test (ALT) method is first used to predict the fatigue life of a full-scale Bogie Frame. Three step-up acceleration load spectrum is compiled for an ALT on the basis of the failure mechanism consistency principle. The ALT of a full-scale Bogie Frame is conducted. Then, the acceleration coefficient and cycle times from the accelerated load level to the working load level are calculated. Based on the equal damage principle, combined with the finite element calculation, the fatigue life of the Bogie Frame under acceleration load spectrum is extrapolated. The ALT method is used to compile the acceleration load spectrum and to perform fatigue tests to analyze the acceleration coefficients and predict the fatigue life for a full-scale Bogie Frame, which provides a reference for the reliability evaluation of large structures.

  • HPCA (China) - Reliability and parametric sensitivity analysis of railway vehicle Bogie Frame based on monte-carlo numerical simulation
    Lecture Notes in Computer Science, 2010
    Co-Authors: Jing Zeng, Fei Yang, Qing-hua Guan
    Abstract:

    In order to study the structure reliability more exactly, the probability analysis method, instead of the traditional constant value analysis method, can be applied to overcome the uncertainty problem of the strength model. The reliability of railway vehicle Bogie Frame is influenced by many factors. In order to ensure the high reliability of Bogie Frame design, the precondition is found to be the dominating factor. In this paper, the parametric finite element model of Bogie Frame was established using the probability analysis method. The plate thicknesses, the service loads and material constants of Bogie Frame were set as the random variables and the distributed parameter values were obtained by statistics. The functions of failure state were established by allowed fatigue strength value and maximum principle stress of parent material or weld location of welded Bogie Frame. The reliability and parametric sensitivities of the random variables were simulated by Monte Carlo Method. Based on the analysis results, the random variables which are sensitive to the reliability of Bogie Frame can be controlled and optimized in practice so as to design high reliable Bogie Frame. The method applied in this paper provided an efficient way to evaluate the reliability and parametric sensitivity of the load bearing structure of high speed trains.

  • Modeling of Rigid-Flexible Coupling System Dynamics for Railway Vehicles with Flexible Bogie Frame
    2009 Fourth International Conference on Innovative Computing Information and Control (ICICIC), 2009
    Co-Authors: Jing Zeng, Qing-hua Guan
    Abstract:

    In order to study the influence of the flexible Bogie Frame on the vehicle system dynamic performance, the rigid Bogie Frame was replaced by the flexible Bogie Frame when the dynamic model was built. Based on the substructure method, the DOFs of the Bogie Frame finite element model were reduced by the Guyan method. When the results of full DOFs modal analysis were consistent with the results of reduced DOFs modal analysis, the rigid Bogie Frame in the dynamic model could be replaced by the master DOFs model. The dynamics results illustrate that it is feasible to build the vehicle system dynamic model by the rigid-flexible coupled method based on substructure method, and the flexible Bogie Frame possesses almost the same influence on the vertical vibration response of primary suspension and secondary suspension with the rigid Bogie Frame. But the flexibility of Bogie Frame affects significantly the vibration of itself and the lateral ride comfort of carbody.

Qing-hua Guan - One of the best experts on this subject based on the ideXlab platform.

  • HPCA (China) - Reliability and parametric sensitivity analysis of railway vehicle Bogie Frame based on monte-carlo numerical simulation
    Lecture Notes in Computer Science, 2010
    Co-Authors: Jing Zeng, Fei Yang, Qing-hua Guan
    Abstract:

    In order to study the structure reliability more exactly, the probability analysis method, instead of the traditional constant value analysis method, can be applied to overcome the uncertainty problem of the strength model. The reliability of railway vehicle Bogie Frame is influenced by many factors. In order to ensure the high reliability of Bogie Frame design, the precondition is found to be the dominating factor. In this paper, the parametric finite element model of Bogie Frame was established using the probability analysis method. The plate thicknesses, the service loads and material constants of Bogie Frame were set as the random variables and the distributed parameter values were obtained by statistics. The functions of failure state were established by allowed fatigue strength value and maximum principle stress of parent material or weld location of welded Bogie Frame. The reliability and parametric sensitivities of the random variables were simulated by Monte Carlo Method. Based on the analysis results, the random variables which are sensitive to the reliability of Bogie Frame can be controlled and optimized in practice so as to design high reliable Bogie Frame. The method applied in this paper provided an efficient way to evaluate the reliability and parametric sensitivity of the load bearing structure of high speed trains.

  • Modeling of Rigid-Flexible Coupling System Dynamics for Railway Vehicles with Flexible Bogie Frame
    2009 Fourth International Conference on Innovative Computing Information and Control (ICICIC), 2009
    Co-Authors: Jing Zeng, Qing-hua Guan
    Abstract:

    In order to study the influence of the flexible Bogie Frame on the vehicle system dynamic performance, the rigid Bogie Frame was replaced by the flexible Bogie Frame when the dynamic model was built. Based on the substructure method, the DOFs of the Bogie Frame finite element model were reduced by the Guyan method. When the results of full DOFs modal analysis were consistent with the results of reduced DOFs modal analysis, the rigid Bogie Frame in the dynamic model could be replaced by the master DOFs model. The dynamics results illustrate that it is feasible to build the vehicle system dynamic model by the rigid-flexible coupled method based on substructure method, and the flexible Bogie Frame possesses almost the same influence on the vertical vibration response of primary suspension and secondary suspension with the rigid Bogie Frame. But the flexibility of Bogie Frame affects significantly the vibration of itself and the lateral ride comfort of carbody.

Nam Po Kim - One of the best experts on this subject based on the ideXlab platform.

  • A study on strength evaluation procedure for the welded Bogie Frame of tilting railway vehicles
    International Journal of Vehicle Design, 2007
    Co-Authors: Jung Seok Kim, Nam Po Kim
    Abstract:

    This paper has investigated the strength evaluation procedure of Bogie Frame for the tilting-train that is being developed by the Korea Railroad Research Institute. In this study, the loading conditions imposed on the tilting train were derived and the static and fatigue strength of the Bogie Frame were evaluated. In order to derive the dynamic loads according to the carbody tilting, the load redistribution effect by carbody tilting, the unbalanced lateral acceleration effect by high-speed curving and the tilting actuator force effect, were considered. Multi-body dynamic analyses were carried out to evaluate the tilting load cases, and strength analysis was performed by finite element analysis. From this study, the structural safety of the Bogie Frame could be ensured.

  • Optimum design of tilting Bogie Frame in consideration of fatigue strength and weight
    Vehicle System Dynamics, 2006
    Co-Authors: B H Park, Jung Seok Kim, Nam Po Kim, Kang Yong Lee
    Abstract:

    This paper addresses the use of finite-element (FE) analysis to calculate the fatigue strength of a Bogie Frame, for the development of tilting trains in Korea. A multi-body dynamic analysis was performed to extract the load condition by tilting on curves. Using the results of the multi-body dynamic analysis and the load scenario setout in the UIC standard, FE analysis was performed to obtain the stress distribution and to calculate the fatigue strength. An attempt was made to minimize the weight of the Bogie Frame using a back-propagation artificial neural network (ANN). The results of this study reveal that the stresses at some nodes are near the fatigue limit in the Goodman diagram and by using back-propagation ANN, the weight of the Bogie Frame could be reduced by 4.7%.

  • Structural Assessment for Bogie Frame of 180km/h Korean Tilting Train
    Key Engineering Materials, 2005
    Co-Authors: Jung Seok Kim, Nam Po Kim
    Abstract:

    This paper has performed the fatigue strength evaluation for the Bogie Frame of Korean tilting train. In order to verify the structural safety of the Bogie Frame, we firstly investigated the loading condition imposed on the Bogie Frame. The Bogie Frame of the tilting train is exposed to the more severe loadings compared with the conventional one because of the tilting of the carbody and the high-speed curve negotiation. We have conducted some multi-body dynamic analyses to extract the load condition by tilting on curve. The finite element analysis is used to obtain the stress distribution. Through this study, we could make sure the safety of the tilting Bogie Frame.