Analytical and Computational Modeling of FRP-Metal Joints Made by Ultrasonic Additive Manufacturing

Abstract

Previous research has developed a process for producing strong fiber reinforced polymers (FRP)-metal joints via ultrasonic additive manufacturing (UAM), and structural tests have been conducted to characterize the mechanical properties of the joints. In this research, an analytical model and a finite element analysis (FEA) model are developed for UAM-produced FRP-metal joints to provide better joint design and application insights. The analytical model applies both the thick-wall cylindrical pressure vessel theory and Tsai-Wu failure criterion to characterize the stress condition in the embedded fibers and the failure mode when tension is applied to the joint. Comparing the analytical model and experimental results of two different sample configurations, the model is able to predict the peak load of the joint with given material properties and joint geometries. Based on the analytical model, an FEA model is built using LS-DYNA to simulate the tensile testing of FRP-metal joint using shell mesh by homogenizing the hybrid portion of the joint. The stress maps obtained from the FEA model for two joint designs show similar distributions when compared to measured digital image correlation (DIC) strain maps, indicating that the failure modes match the experimental results. The FEA simulation results agree well with the experimental result for peak load and displacement at fracture, with an error of less than 5%.