Experimental and numerical investigation on test methods for mode II fracture of composite‐titanium adhesively bonded structures

Abstract

AbstractThe investigation on fracture test methods for dissimilar materials adhesively bonded structures is urgent. In this study, three mode II fracture test methods for composite‐titanium adhesively bonded structures are experimentally and numerically studied. A manual inverse fitting method is adopted to obtain accurate cohesive models, and sensitivity evaluation of test methods is comprehensively conducted. The results show that GII of the experimental end‐notched flexure (ENF) test is nearly 20% greater than end‐loaded split (ELS). The effect of friction can be ignored, while all methods are highly dependent on the adherend's thickness, especially the maximum deviation of ELS that is 23.74%. In addition, the condition that the adherend with smaller flexural stiffness places outside the bending direction should be avoided to achieve mode II dominant possibly. In summary, the ENF test method with span length of 100 mm and small adherend's thickness is recommended for the mode II fracture test of the dissimilar materials adhesively bonded structures.