Rate-dependent Shear Strength and Stress Relaxation of Adhesive Joints

Abstract

For single-lap joints of acrylic adhesive and aluminium adherends, tensile lap shear tests at various crosshead speeds, and also stress relaxation tests were performed at room temperature. In the tensile lap shear tests, it was found that the shear flow stress of the adhesive resin increased remarkably with increasing shearing speed. In the stress relaxation tests, the stress decreased rapidly at the early stage of the relaxation tests, and it gradually approached asymptotic stress values. In order to describe such rate-dependent deformation characteristics of adhesive resin, a viscoplastic constitutive model has been presented in this paper. The shear stress-strain responses, as well as stress relaxation behaviour, predicted by the present model agreed well with the corresponding experimental results.