MBS/FEM co-simulation for hybrid modeling of railway dynamics

Nowadays in railway traffic, specific speed limitations exist depending on the train charge, due to a fragile subsoil or even an old building that has to be preserved. Depending on the type of vehicle, the type of soil or even the vehicle speed, the groundborne vibration characteristics can significantly vary. It becomes thus important to predict the vibrations generated by a train passing on a track in the surrounding soil. In order to achieve this prediction, a hybrid modeling approach, consisting in a vehicle modeled using the minimal coordinates approach in multibody systems theory and a soil modeled using a finite element method, is developed. The recoupling of this hybrid system is performed using co-simulation between two different software packages with their own solvers. The first software is EasyDyn, an in-house C++ library package dedicated to multibody dynamics and the second software is ABAQUS that is dedicated to finite element analysis. The aim of this paper is to illustrate the results given by this hybrid model. Then two different co-simulation schemes (the sequential Gauß-Seidel scheme and the parallel Jacobi scheme) will be used and compared in terms of accuracy for this specific railway application

Comparison of X–T and X–X co-simulation techniques applied on railway dynamics

peer reviewedCo-simulation techniques start to be of high interest when building a vehicle–track–soil model dedicated to ground-borne vibrations’ assessment. If this model includes a relatively comprehensive representation of the vehicle, track, and soil subdomains, different solvers may be used to simulate them. In this paper, the vehicle and track are modeled in a multibody dedicated software and the soil is simulated in a finite element analysis software. The aim of this paper is to investigate the effect of displacement/force and displacement/displacement co-simulation types in the case of coupled railway-soil dynamics. Both Jacobi and Gauß–Seidel approaches are used without iterations and using a zeroth-order hold extrapolation of the coupling variables. The modeling of the subdomains is described and an implementation of the co-simulation is proposed. By observing the ground and vehicle motions, as well as the peak particle velocity of the soil with respect to the distance from the track, it is stated that the choice of displacement/force or displacement/displacement co-simulation type has a significant effect on the results. Indeed, while the displacement/displacement type offers a larger stability region than the displacement/force type, the accuracy of the results is more heavily affected

A vehicle/track/soil model using co-simulation between multibody dynamics and finite element analysis

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Effect of applied force cosimulation schemes on recoupled vehicle/track problems

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