Development and Validation of a Process Chain for a Real-Time Capable Simulation of a Vehicle with a Cracked Rear Axle Tie Rod

Up to now, cracked axle components are subjectively examined in real vehicle tests. In order to save development costs and time, these tests should be carried out in a dynamic driving simulator. A necessary prerequisite for this is a real-time capable full vehicle model that correctly represents all crack-related non-linear effects. This publication develops and validates a purely virtual process chain to describe cracked axle components in real time. Rear axle tie rods with different crack lengths at the same position are considered as an example. First, the stiffness behaviour is simulated at the component level and compared with real tests. The determined stiffness curves serve as a basis for the parameterisation of a physical substitute model. The tie rods are modelled as a non-linear FE component, as a linear flexible body and via the physical substitute model. These modelling approaches are integrated and validated in a FE semi-axle model as well as in the MBS full vehicle model. It is shown that the physical substitute model provides very good results. Finally, the full vehicle model with a cracked tie rod is converted into a real-time model based on elastokinematic maps and validated based on the MBS model.