Transient Dynamic Fatigue Analysis of Automotive Structures using Proving Ground Road Profiles

A methodology is developed using linear system model and road profiles for fatigue life prediction of automotive structures. The main focus is to develop a robust process capable of handling long proving ground tracks which will provide reliable damage prediction away from suspension and an A-to-B class estimate towards the suspension. The method uses normal mode shapes to approximate response and transient dynamic solution is obtained using a special purpose solver, which includes new damping formulation. A new process was used to identify damage critical road tracks from a set of proving ground roads. For a typical vehicle, the method identified more than 80% of peak damage locations predicted using measured loads; some of the damage estimates being very close.