Effect of temperature and humidity on the creep and aging behavior of adhesive joints under static loads

To study the creep and aging behavior under the combined effect of temperature, humidity and static load, polyurethane adhesive was selected to make butt joints. The creep properties of the joint were analyzed experimentally under different static loads in hygrothermal environment. At the same time, an aging test under the combined effect of temperature, humidity and static load was carried out, and the variation law of the residual strength of the joint with the load and loading time was obtained. The complex fracture behavior of polyurethane adhesive joints was studied from macro to microscale. The results show that the hygrothermal environment had a significant effect on the creep properties of polyurethane adhesive joints. The creep strain rate of the joint was significantly higher, and the failure fracture time was shorter in the high temperature and humidity environment. When the temperature, humidity and static load were coupled, the joint failure strength decreased with time. With increasing load, the decline rate of the failure strength increased significantly. The interface failure of the joints and the hydrolysis reaction of the polyurethane adhesive were the main reasons for reducing the failure strength.