Integrated Panel and Skeleton Automotive Structural Optimization

Previous work in structural optimization for the automotive structure has been limited to beam models of the major load-carrying structure. This was primarily done to reduce the amount of computer resources required to minimize the mass. In this study, techniques necessary to include a moderately complex representation of the panels are developed in which some compromises between model fidelity and solution time must be accepted.

As an example, plate elements have been included in a vehicle structural optimization model to represent the roof, floor, dash, motor compartment, and rear quarter. Minimum mass designs subjected to stress, displacement, and frequency constraints are obtained by structural optimization. It was found that most panels were at minimum gage in the optimum design. This suggests that these panels are designed by local criteria as opposed to being controlled by global load and stiffness criteria. A few panels in the highly stressed areas are affected by the global load conditions and should be included in this portion of the optimization.