Multi-material forming using DP780 and CFRTP

Abstract

Recently, carbon fiber reinforced thermo-plastic (CFRTP) has been used widely in a number of composite applications owing to the growing concerns about reducing energy consumption and protecting the environment. Various attempts have also been made to apply CFRTP to automotive parts in place of metal alloys because of the superior mechanical properties and being lightweight. Generally, CFRTP is applied to automotive parts with metal alloys because of the high material price. Therefore, research has been conducted on the multi-material forming process to reduce the process price. However, it is difficult to predict the formability of multi-materials and to design the shape of a CFRTP part because there is little research on the design and formability prediction of multi-materials. The aim of this study is to develop the B-pillar on automobile reinforced with CFRTP. Since the B-pillar is deformed simultaneously with CFRTP and DP780, the following study is required. First, a shape optimization analysis was performed to design the B-pillar reinforcement using CFRTP. The determined shape of the B-pillar reinforcement was used to determine the thickness of the product that satisfied the bending stiffness of the conventional product. Next, the friction coefficient at the interface between DP780 and CFRTP was measured for a multi-material forming analysis. The problems that occurred during forming process were analyzed through a multi-material forming analysis. Finally, the developed product was manufactured through the same method as in the analysis, and any problems were evaluated and analyzed.