CAE-based driving comfort optimization for passenger cars

Abstract

Excellent vehicle dynamics performance has strongly contributed to the appealing driving experience of Ford vehicles. This is achieved via application of advanced suspension concepts, high structural stiffnesses of body and chassis components and extensive tuning work on the vehicle proving grounds. One of the key challenges in vehicle engineering is to optimize vehicle driving comfort without degrading the steering and handling performance. The part of driving comfort discussed in this paper is primarily tactile vibrations up to f = 100 Hz. This paper describes how Multi-Body Dynamics (MBD) Computer Aided Engineering (CAE) tools are applied to optimize such vibrations in an early phase of the development process. A first example demonstrates the effect of subframe isolation to ride comfort via analyses of the forces transmitted to the vehicle body. A second example demonstrates the sensitivity of bushing stiffness to impact harshness using a full vehicle model. A final example demonstrates how impact harshness can be optimized using different levels of compliance split between the subframe and suspension bushings.