NUMERICAL ANALYSIS ON THE BOND PERFORMANCE OF DIFFERENT ANCHORED JOINTS UNDER MONOTONIC AND CYCLIC PULL-PUSH LOADING

Abstract

The research on the bond behaviour of hybrid joints has increased in recent years as a result of their widespread use in many industry sectors that have the goal of building lightweight structures with good long-term performance. Although the bond behaviour of hybrid bonded joints under monotonic load is now well understood, their bond behaviour under cyclic loading still has to be improved. The goal of this study is to mitigate that gap by presenting a series of numerical simulations of Carbon Fiber Reinforced Polymer (CFRP) bonded onto a steel substrate through the use of the Distinct Element Method (DEM). Different bonding methods are considered and the results provided by the Externally Bonded Reinforcement (EBR) are used as reference. The other simulated bonding techniques included the linear increase of the width of the CFRP composite, the assumption of a mixed adhesive in which two solutions were investigated, and using an additional steel plate bonded on the top of the CFRP. The simulations that followed the selected cyclic loading history (loading/unloading) allowed us to notice a decrease in the joint bond strength with the number of cycles when compared to the monotonic loading simulations. However, the strength of the CFRP-to-steel joints was not affected if the overlapping bonded joint had a long length. On the other hand, the simulations of the CFRP-to-steel joints with a short bonded length revealed that the strength and ductility of these specimens are severely affected whether subjected to a monotonic or the adopted cyclic loading history.