2017 年 43 巻 2 号 p. 65-73
Carbon fiber reinforced thermoplastics (CFRTP) have attracted intense attention because of their potential application in both weight reduction and high-volume manufacturing of automotive components. In this study, we focus on the flexural behavior of automobile panel parts by finite element method (FEM) to verify that the optimal structural design of CFRTP is significantly lighter than that of steel with the same stiffness and strength. There are three typical reinforcing structures for CFRTP: ribbed, gradual thickness distribution, and sandwich structures. We investigate the optimal structural design and verify its applicability by taking account of the analytical accuracy for each structure. Our previous research showed that the numerical simulation of ribbed structures does not conform to the experimental results because of low analytical accuracy. Instead, structures with a gradual distribution of thickness and sandwich structures have been used in this study to minimize the weight using a shape optimization technique. The results not only demonstrate nearly 70% reduction in weight as compared with a steel panel possessing the same stiffness, but also indicate that the strength criteria are satisfied.