Cyclic testing of adhesives: Cyclic shear stress-strain loading of adhesive layers

A hysteresis measurement method was used to study and analyze mechanical behavior of adhesive layers under cyclic loading. The tests were performed by applying a periodic triangular load with constant speed of shear deformation of adhesive layer. The elastomeric behavior for the low modulus polyurethane adhesive was analyzed by shear strain rate-controlled multi-step test. The analysis suggested that dynamic shear modulus and dynamic stiffness reacted more sensitively than energy ratios and was more suitable to measure and assess structural changes.