Ilja Kalmykov, Michael Burger, Carsten Dehning (Fraunhofer Gesellschaft)

at NAFEMS Seminar "The Role of CAE in System Simulation", November 2011 in Wiesbaden

The combination of multi-body dynamics (MBS) and finite element (FEM) simulations can increase the efficiency of computational engineering design tasks addressing vehicle dynamics, structural mechanics or engine dynamics and other areas.

One widespread method consists of integrating a linear model description of the flexible body into the MBS program, also known as a model reduction approach, using methods like “Craig-Bampton” or others. However, there are applications where linear models for flexible bodies are not sufficient.

This is in particular true for the integration of tire models into vehicle dynamics simulations. The simulation code Abaqus from SIMULIA provides the capability to describe a tire component as a nonlinear model. In order to take the full features of non-linear component models into consideration in a system analysis simulation, both FEM and MBS tools can be coupled using the co-simulation interface MpCCI. MpCCI is a general co-simulation interface provided by Fraunhofer SCAI and supports most of the leading FEM and CFD codes. First extensions for functional and system codes like MSC.Adams are available and are being developed further.

The impact of co-simulation can be demonstrated with an example from the vehicle dynamics area. In this example, a nonlinear finite element tire model and a rigid body vehicle model have been coupled. Main fields of interest were parts which inherent takes plastic deformation due to functional purpose, such as tires. In a concrete load case - a passenger car driving over a pothole in the road - the relevant co-simulation key features has been evaluated in some detail.