Abstract
In deterministic optimization of structures, the objective function, design constraints and design variables are all treated in a nonstatistical fashion. In some instances, deterministic optimization promotes structures with less redundancy than obtained with more conventional design procedures. Consequently, deterministic optimized structures will usually have higher failure probabilities than unoptimized structures. Therefore, a balance must be developed between the satisfactions of the design requirements and the objectives of reducing manufacturing cost. This paper proposes the reliability-based design optimization (RBDO) technique, which enables the optimum design that considers confidence level for vehicle structures. Response surface method (RSM) is utilized to approximate the performance functions describing the system characteristics in the RBDO procedure. The proposed optimization technique is applied to the pillar section design of vehicle structure. By applying the proposed RBDO methodology, it is possible to optimize the pillar section considering the reliability of the specific performance function.