On the mechanical performance and damage evolution of rivet-bonded composite T-joint under three-point bending: A combined experimental and numerical study

Abstract

This paper presents an experimental and numerical study on the damage characteristics and failure modes of carbon fiber reinforced thermoplastic (CFRTP) T-joints subjected to quasi-static bending load. First, tensile loading tests were conducted on 6061-T6 aluminum alloy and 304 stainless steel specimens at various triaxial stress levels. Then, on the basis of these tensile tests, Finite Element Modeling (FEM) was used to determine the relationship between the metal’s stress triaxiality and failure strain, allowing for the parameter determination of the Johnson–Cook​ failure criteria. After fabricating the T-joint in vehicle body using thermoplastic carbon fiber reinforced composites and 6061-T6 aluminum alloy with rivet-bonded joining method, the mechanical performance of the structure was evaluated under bending load. The T-joint was tested up to failure under quasi-static loading conditions and load–displacement curves were obtained to evaluate the load-bearing capacity and bending resistance. In the FE analysis, the Johnson–Cook, Hashin, and Cohesive Zone Model were used to numerically simulate the bending failure mode and mechanical properties of the T-joint subjected to bending loading. Good agreement was achieved between numerical and experimental results, which can serve as a reference value for the study of rivet-bonded composite joints with dissimilar materials.