Cone-and-Plate Shear Stress Adhesive Test

A test geometry is described which will produce a state of essentially pure constant shear stress in an adhesive bond. The adherends are fabricated from two cylindrical elements, one with a convex conical end section and the other with a flat plate end section. The axes of these two cylinders are aligned and the two end sections are bonded together with the test adhesive. The adhesive test volume is a disk with conical indentation. An analysis of the state of stress in the adhesive, with torsional loading of the adherends, shows that a single component of shear stress is present and this shear stress is essentially constant throughout the adhesive volume for small values of the cone angular opening. The advantages of a constant shear stress adhesive test are many and one of the most significant is the ability to accurately measure in-situ material properties. Preliminary test results are reported.