An experimental investigation of static and fatigue behavior of various adhesive single lap joints under bending loads subjected to hygrothermal and thermal conditions

Abstract

ABSTRACT The objective of this study is to investigate the impact of hygrothermal and thermal aging on adhesive bonding joints of similar and dissimilar specimens. The research focuses on the single lap joint (SLJ) configuration using Aluminum/Aluminum and CFRP/CFRP for similar bonding and Aluminum/CFRP for dissimilar bonding. Understanding the behavior of such joints over time and eventual failure can enhance their durability, reliability, and safety in structures. The study submerged SLJ specimens in tap water at a temperature of 53°C for 20 days to assess hygrothermal aging and kept another group of joints in an oven set at the same temperature for thermal aging. The research evaluated the strength of samples that underwent no aging, hygrothermal and thermal aging, tested through three-point bending tests. Various load levels were tested utilizing a recently designed fixture, including 70%, 60%, and 50% of the static load level. Results showed the highest joint strength in Aluminum/Aluminum SLJs and reduced strength following thermal and hygrothermal aging. The failure patterns and number of cycles leading to failure also varied with load percent and aging. Ultimately, the study aimed to evaluate and contrast the strength of samples that underwent different aging processes.