Development of an MBS/FEM coupling interface with application to vibrations generated by railway vehicles.

Description

Recent decades have been fertile in terms of development of vehicle dynamics simulations. But the usual applications dedicated to the train design rarely take into account ground vibrations. In order to assess the influence of vehicle dynamics on track deflection and therefore on ground wave propagation, the vehicle/track/soil system must be studied globally. Nowadays, multibody system (MBS) simulation tools are widely used to assess the dynamic performances of a vehicle, in terms of interior comfort or train stability. In order to predict the railway vibrations, a model has been developed in the Department of Theoretical Mechanics, Dynamics and Vibrations, consisting in simulating in a first step the vehicle-track subsystem, in order to extract the ground forces which are, in a second step, applied to a finite element model (FEM) of the soil. This assumes a decoupling between the two subsystems. The purpose of this research is to couple the vehicle-track and the soil submodels by co-simulation. Applicability of co-simulation techniques has been largely studied by many researchers, including the development of improved methods (gluing algorithms, force/displacement coupling method, …) with application for solving coupled MBS/FEM problems. In the proposed work, we want to develop an interface for a MBS/FEM coupling in the application of railway-induced ground vibrations. As a practical problem, a hybrid simulation will be considered between the vehicle/track and the soil models. As modelling environment for the FEM, the commercial simulation package ABAQUS is used; a home-made C++software is dedicated to the MBS. Different numerical coupling will be analysed in order to select the most efficient method in the proposed railway application. Various simulations will be performed (tramway, domestic train, high-speed train) and validated with experimental results. Limitation of the present procedure will be also analysed.