Optimization of vehicle NVH performances becomes possible only if assessing modifications does not require time-consuming analysis of large FE models. In this paper, an engineering approach to analyze and optimize the global bending and torsion modes of a vehicle body is presented. Concept modifications in the body beam-like sections and in the joints are analyzed using the body reduced modal model. This small-sized model can be used to quickly and accurately optimize the low-frequency vehicle performance. Beam elements from standard FE library are used to implement the modifications in the beam-like sections.
These modifications are considered with respect to the existing model, so as a first step, the local equivalent beam properties are evaluated from the body FE model. The joint modifications are considered through static superelements. They consist of a stiffness formulation between the end points of the joint connected to the beam layout. Here also, the modifications are considered with respect to the existing design.
Simple example models are used to assess the accuracy of various equivalent beam and joint representations, and come to an industrial guideline on their validity and applicability for fast modification analysis. The proposed approach is then demonstrated on an industrial vehicle model.
