Strength and failure modes of adhesively bonded composite joints with easily fabricated nonflat interfaces

摘要

Modifying the geometry of a bonded area improves the strength of adhesively bonded joints. In this study, the joint performance of an adhesively bonded joint with nonflat interfaces was experimentally and numerically evaluated. Various parameters of embedded reinforcements were studied. A new fracture mechanism, termed a two-stage failure mode, was discovered. Moreover, two dominant factors were identified as influencing the strength of the bonded joints. The optimized nonflat-interface specimens exhibited improvements in the ultimate load and average shear stress of up to 45% and 52%, respectively, compared with typical flat-interface specimens. Applying the proposed nonflat joints together with artificial defects has little influence on the ultimate load of specimens and further reduces total weight, and joints can be fabricated without using an additional mold. Therefore, these joints are significantly advantageous for promoting this technique in the industry.