Evaluation method of adhesive joint strength based on the normal–shear stress of adhesive interface and its application in engineering

Traditional material-joining techniques are facing enormous challenges due to the wide use of new materials in engineering. Therefore, the application of bonding technique in engineering becomes more and more important. In order to facilitate designers evaluating the joint strength of bonding structure, a fast and simple strength evaluation method which can be easily used for adhesive joints under complex working conditions was proposed in this article. The normal and shear stresses of the adhesive interface were selected as the main research objects in the method considering the complex working conditions that many bonding structures may face in engineering. Butt joint, single lap joint, and several groups of scarf joint specimens with different adhesive angles were fabricated. Numerous repetitive tensile tests were conducted to obtain the adhesive failure stresses under different conditions. The adhesive failure stress envelope was fitted based on the experimental data, and the evaluation method of adhesive joint strength was developed in detail. Finally, verification experiments were designed. The results indicate that the evaluation method of adhesive joint strength based on the normal–shear stress of the adhesive interface is simple and effective in engineering application.