For the estimation of the mechanical behavior of adhesively bonded joints, simple polymer samples (e.g., dog bone test) are of limited use, as chemical composition and surface pretreatment of the adherends cannot be considered. This is of special importance if substrate-sensitive adhesives, such as anaerobics, are applied. In technical practice, joints should, wherever possible, be loaded in shear; therefore such destructive lap tests have established themselves as the standard in-situ test methods.
For the design of a joint, the elastic parameters (two out of Young's modulus E, shear modulus G, and Poisson's ratio v) and - in some cases - the failure stress and strain are usually required. For the determination of these characteristics, the thick-adherend tensile-shear test according to ISO 11003-2 (ASTM D 3983-81) is often applied. Substrate deformation can be taken into account by appropriately attached extensometers2 and numerical correction.3