Self-Piercing Rivet을 이용한 CFRP/Steel/Aluminum 3매 겹침 접합평가

Abstract

Multi-material integration between lightweight materials such as aluminum alloy, carbon fiber reinforced plastic (CFRP), ultra-high-strength steel (UHSS), etc. is one of the key techniques for achieving weight reduction. For its wide use, productive and reliable technologies for the dissimilar joining of the lightweight materials is required. In this study, three-layer dissimilar joining of CFRP, GA-590DP, and Al5052-H32 was investigated using self-piercing rivet (SPR). The tensile shear load and the failure modes were evaluated for four different layering sequences. It was identified that the failure originates from the CFRP which rips out the rivet as it tears off from the joint. Therefore, the joining strength was stronger when the CFRP was sandwiched between the metals preventing the fractured CFRP from prematurely ripping out the rivets. Also, it was found that using Al5052-H32 as the lower sheet exhibited similar joining strength compared to that of using GA-590DP as the lower sheet. Finally, the tensile shear load increased as the CFRP thickness is increased in all the layering sequences.