Theoretical Approach for Pillar Trim Design to Reduce Head Injury

This paper presents an analytic method to estimate the proper space and stiffness of the vehicle's pillar trim to meet FMVSS 201 head injury criteria. A practical guideline curve, which is used in determining the adequate space and stiffness of pillar trim, is derived assuming haversine curve for the head impact pulse. Rib structure of pillar trim, which has a required stiffness, is designed using further simplification that models the BIW and the trim as equivalent springs. The required stiffness of the trim was achieved by adding a rib structure to it, and the shape of the rib structure was obtained using finite element analysis. Finite element analysis and experiment were conducted to validate the design of the trim, and the results were very close to the required stiffness.