Identification of joints for a load-adapted shape in a body in white using steady state vehicle simulations

Abstract

Joints are cost-intensive and have a great influence on the properties of a joined assembly. There is a wide variety of research on optimizing the joint distribution in an assembly. These optimizations are performed with joint models, which are rotational symmetrical and thus have transversely isotropic properties. The potential of joints with direction-dependent stiffness is not exploited in those studies. Joints with different shear stiffness can be oriented concerning the local planar force distribution. In this way, individual joints can be designed regarding the local force distribution and the overall properties of the assembly.This paper presents a method to identify these joints based on numerical simulations. For this purpose, a multibody full vehicle model is created, and various steady state driving simulations are carried out. Within these simulations, both the forces at the suspension struts and the connections between subframe and body are determined. Subsequently, these forces are defined as input of an implicit finite element model of the vehicle body, where the joint forces are calculated. Finally, the joint forces of various driving maneuvers and static load cases are superposed and evaluated.With the presented methodology the joints which are suitable for a load adapted shape are successfully determined. The results show great potential for the use of joints with fully anisotropic properties in a vehicle body, which is currently not realized. Joints with three different stiffness could enhance the stiffness properties of a vehicle body.

Keywords

• Load adapted joints
• Full vehicle simulation
• Selection methodology
• Inertia relief
• Design engineering