Research on the static strength performance of adhesive single lap joints subjected to extreme temperature environment for automotive industry

Adhesive bonding technique is widely studied and adopted in automotive industry in recent years, which leads to satisfactory joint mechanical properties and lightweight effects. In this study, the static mechanical performance of adhesively bonded joints after different temperature exposures was investigated through joint quasi-static shear-strength test. A response surface method using MATLAB programming was utilised to analyse the influences of exposure temperature and adhesive mechanical attributes on joint static strength. Visual inspection and scanning electron microscopy were later performed on the fracture surfaces to explain the failure mechanisms. Test results showed that long-term temperature exposure caused degradation in joint strength and failure displacement. It was found through response surface curve that comparing to higher temperature exposure, lower temperature causes greater and faster environmental degradation. Different types of fracture surfaces in the overlap zone were also detected through comparing adhesive joints under different environmental treatments.