Design of Suspension Components for Small Overlap Frontal Impact (SOF) Analysis

The Insurance Institute for Highway Safety (IIHS) Small Overlap Frontal (SOF) impact assessment program is one of the latest challenges for the automotive development. The SOF load bypasses the primary crumple zone structure and concentrating the force in the front wheel, suspension and firewall - areas not traditionally designed to absorb and dissipate crash energy. Design changes of architectural components at later stages of product development is very difficult and expensive. This paper deals with the procedure to improve SOF performance through CAE as well as to develop the physical test cart to avoid the full vehicle SOF test. CAE procedure developed on chassis subsystem level to validate the SOF performance of front suspension. Using this procedure, design changes in the suspension components to improve the SOF performance can be done by keeping the suspension durability and other performance requirements as intact. This subsystem model is arrived from the full vehicle crash model and test cart developed using this procedure. We have verified the performance in CAE and correlated test results with physical model. Also, consistency of the test cart performance validated with different vehicle architectures. Ninety percent correlation of the loads distribution in the suspension components with the test results is achieved. The proposed method helps in front loading concepts in vehicle development program, and reduces the cost on full vehicle testing for the SOF performance of front suspension components.