Study on Nondestructive Inspection Method of Single-Lap Adhesive Joints to Eliminate the Influence of Inspector's Behavioral Characteristics
In this study, we conducted a tensile shear test according to JIS K 6850 for a simple superposed adhesive joint, and as a result, it was found that the expected adhesive strength can be obtained only when cohesive failure occurs. The surface enlarged length was measured from a micrograph that observes the surface texture of the boundary between the adhesive and the adherents, and it was found that cohesive failure occurred when the length was longer than a certain length. Surface enlarged length is a new way of thinking. It measures the length of the ridgeline of the unevenness in the microscopic photograph of the surface roughness. By doing so, we can quantitatively determine the effective adhesive length. Effective adhesion length is the length of adhesion of the adhesive as viewed microscopically. We can know the adhesive effect by examining the effective adhesive length. Therefore, we found the relationship between the surface enlarged length (= effective adhesion length) of the bonding interface of the simple superposed adhesive joint and the adhesive strength. Then, it was verified whether adhesion strength could be predicted by setting the standard surface enlarged length as a threshold. As a result, we developed a nondestructive inspection method that can estimate the failure mode after the tensile test.
Luis Rodríguez-Tembleque, Jaime Domínguez and Ferri M.H. Aliabadi
G. Hotta et al., "Study on Nondestructive Inspection Method of Single-Lap Adhesive Joints to Eliminate the Influence of Inspector's Behavioral Characteristics", Key Engineering Materials, Vol. 774, pp. 283-288, 2018