Stochastic Analysis of a Body-on-Frame Vehicle to Achieve Reliable and Robust Shake Performance

This paper addresses the influence of variability resulting from mount / bushing rates and gages of major structural members to the vehicle shake response. Comparisons of two vehicles to study the concepts of reliability and robustness from vehicle shake perspective are presented. The relationship between vehicle tunability and robustness has been addressed.

The First Order Second Moment (FOSM) method is used to provide an initial estimate of the variability or robustness of the design. The influence of body gages, body mount rates and suspension bushings, for two different modal management strategies, has been included. These studies have been compared with Monte Carlo Simulation using a dynamically condensed model.

The influence of modal management as a key enabler to achieve a reliable NVH performance has been presented. Various factors influencing robustness in modal management and vehicle shake performance have been discussed. Critical vehicle design parameters which, need to be controlled with tight tolerances to achieve a very robust and reliable system from shake perspective have been identified.