Papers by Keyword: Multibody Dynamic Simulation

Abstract: For high-speed railway carbody structure durability analysis problems in China, one integrated method based on MBS (multibody simulation) is proposed here. Firstly, one EMU (Electricity Multiple Unit) full vehicle was performed to dynamic modeling and simulation. The numerical simulation results were applied to illustrate the vehicle dynamic characteristics. And the relationships between structural strength, stiffness, and frequency characteristics were also studied. Secondly, the multidisciplinary design technique was used to solve multi-mode coupled vibration of carbody structure on the cumulative effects of local vibration and damage effects, as well as structure light-weighting and other parallel optimization problems. Finally, the effective measures were proposed to control carbody structure’s physical failure.

Abstract: Railway vehicle structure fatigue life consumption monitoring can be used to determine fatigue damage by directly or indirectly monitoring the loads placed on critical vehicle components susceptible to failure from fatigue damage. The sample locomotive carbody structure was used for this study. Firstly, the hybrid fatigue analysis method was used with Multi-Body System (MBS) simulation and Finite Element Method (FEM) for evaluating the carbody structure dynamic stress histories. Secondly, the standard fatigue time domain method was used in fatigue analysis software FE-FATIGUE and MATLAB WAFO (Wave Analysis for Fatigue and Oceanography) tools. And carbody structure fatigue life and fatigue damage were predicted. Finally, and carbody structure dynamic stress experimental data was taken from this locomotive running between Kunming-Weishe for this analysis. The data was used to validate the simulation results based on hybrid method. The analysis results show that the hybrid method prediction error is approximately 30.7%. It also illustrates that the fatigue life and durability of the locomotive can be predicted with this hybrid method. The results of this study can be modified to be representative of the railway vehicle dynamic stress test.

Abstract: In structural design for safety and durability, the primary concern is to reduce structural fatigue damages due to random dynamic loadings during the service life of locomotive vehicle system. Rolling stocks is facing new sever safety problems, such as bogie frame structure components fracture and safety-based design optimization to durability of locomotive. The objective of the current research is to find the most efficient approach to predict structure safety with Multi-Body Simulation (MBS) and Finite Element Method (FEM). The method is implemented to evaluate bogie frame fatigue damages under dynamic stochastic loadings. The time varying boundary conditions and dynamic load history acting on the large structure can be evaluated by applying the Multi-body Simulation technique in software SIMPACK. Stress/strain analysis technology with software ANSYS yields the danger stresses in the critical locations of the structure depending on the unite loads. And modal analysis is used to determine frequencies and mode shapes of structure. Based on these danger stresses distribution and dynamic load time history, fatigue life can be estimated with Palmgren-Miner theory. The standard time history method involves stress or strain cycle counting, damage prediction, and finally life estimation in Software FE-Fatigue with factor of safety technology.