Crush Simulation of Cars with FEA

Abstract

This article illustrates that while crash analyses have been carried out with success, a crush analysis is much more difficult to achieve. In a crash analysis, the inertia effects smooth out the nonlinearities and deficiencies in the solution algorithms. In a crush test, it takes about 10 to 30 seconds to crush the car to the required maximum displacement of the steel plate. Since the critical time step for explicit time integration in a crash code is on the order of microseconds, millions of time steps must be used to perform the analysis in a physically correct manner. With sufficient numerical experimentation, involving changes to the load application speed and perhaps to other parameters, LSDYNA results can be obtained that would match laboratory test results, but such experimentation requires a lot of time and computational effort. A solution that corresponds to the actual physical conditions and is computationally efficient is much more desirable. Such a computed solution is given above for a Ford Taurus model. The calculated crush results obtained with ADINA using implicit integration compare favorably with the laboratory test results.