Multi-objective design optimization for crash safety of a vehicle with a viscoelastic body and wide tapered multi-cell energy absorber using DOE method

Due to the extensive use of cars and progresses in the vehicular industries, it has become necessary to design vehicles with higher levels of safety standards. Development of the computer aided design and analysis techniques has enabled employing well-developed commercial finite-element-based crash simulation computer codes, in recent years. The present study is an attempt to optimize behavior of the structural components of a passenger car in a full-frontal crash through including three types of energy absorptions: (i) structural damping of the car body, (ii) viscoelastic characteristics of the constituent materials of the bumper, and (iii) a proposed wide tapered multi-cell energy absorber. The optimization technique relies on the design of experimental (DOE) method to enables finding the absolute extremum solution through the response surface method (RSM) in MINITAB software. First, the car is modeled in PATRAN and meshed in ANSA software. Then, the full-scale car model is analyzed in ABAQUS/CAE software. The optimization has been accomplished through a multi-objective function to simultaneously, maximize the observed energy and minimize the passenger’s deceleration. Results are verified by the experimental results and effects of using non-equal importance coefficients for the absorbed energy and passenger’s deceleration in the multi-objective function are also evaluated. Influence of the optimized parameters on the frontal crash behavior of the vehicle body structure and passenger’s deceleration is investigated, too.