Strength Degradation of Adhesively Bonded Single-Lap Joints in a Cyclic-Temperature Environment Using a Cohesive Zone Model

Adhesively bonded joints are widely used in automotive industry. Adhesively bonded joints permit to have more uniform stress distributions, join complex shapes, and reduce the weight of the structures. The requirement to reduce the weight of automobiles is also increasing the application of composites. In this article, CFRP (carbon fiber-reinforced plastics) composite was used in experimental tests. In many cases, adverse environments cause non-negligible degradation in joints mechanical performance. So a combined experimental–numerical approach was developed to characterize the effect of cyclic-temperature environment on adhesively bonded joints. Experimental tests were carried out on single-lap joints with CFRP and steel adherend in a cyclic-temperature environment. A cohesive zone model was taken into consideration to predict the results observed during the experimental tests and an environmental degradation model was developed. Scanning electron microscopy was utilized to investigate the fracture surfaces.