The Influence of Combined Hygrothermal Environment and Load on the Performance of Adhesively Bonded CFRP–Aluminum Alloy Joints

Abstract

To provide reference and guidance for the design of the adhesive structures of the CFRP–aluminum alloy in the actual service environments, the aging laws of the adhesive joints under the hygrothermal environment and the load were studied in this paper, and a prediction method considering different aging conditions was proposed based on the cohesive zone model. The structural adhesive Araldite® 2015 was selected to fabricate the CFRP–aluminum alloy butt joint, and the durability tests were carried out under the condition of hygrothermal cycle, combined hygrothermal cycle and static load, and combined hygrothermal cycle and alternating load. The residual strength and failure modes of the joint after aging were analyzed. The results showed that the strength of joints decreased markedly after 60 h of hygrothermal cycle. The load further aggravates the aging of the joint, the adverse effect of dynamic alternating load on the failure strength of joint is more obvious than that of the static load; at the same time, the failure mode of joint has changed after aging, and compared to the selected CFRP, adhesive performance decreased more obviously; The damage factors under different aging conditions were defined, combined with the failure criterion obtained by the test, the classical double linear traction–displacement cohesion rule is modified, and the residual strength of the adhesive joint after aging is predicted by numerical simulation analysis.