A Study on the Optimal Design of Automobile Interior Plastic Parts (A-Pillar Trim) Considering Heat-Resistant and Mechanical Characteristics

Interior parts that are composed of plastic usually deform under various temperature conditions. It is necessary to obtain the material properties for an analysis of the thermal deformation under the heat cycle test. Specifically, creep data of plastic material was introduced for studying the time-dependent deformational behavior of the pillar trim in the heat cycle test. The time-hardening version of the power-law creep model was applied to account for the permanent deformation following the heat cycle test, which was verified through a comparison of the test results with the result of finite-element analysis for a simple model. In this study, a methodology was developed for the optimal design of the A-pillar trim in terms of the positions of the mounts. The analyzed results were used to approximate a function that was constructed by the response-surface method. Design procedures were repeated to minimize the thermal deformation at the areas of interest. We also developed a methodology for designing the rib pattern of A-pillar trims. Nonlinear finite element analysis has been implemented and integrated with a method of sensitivity analysis for minimizing the thermal deformation at the areas of interest.