Mechanical behavior of adhesively bonded butt-joints under cyclic loading: Experiments and constitutive model

The cyclic loading experiments on HP-172B sealant bonded tubular butt-joints were carried out with the strain-controlled mode, and the effects of strain amplitude and mean strain on the cyclic relaxation stress and cyclic softening variable of the bonded butt-joint were investigated. The experimental results show that the stress-strain response curve of the butt-joint presents a corrugated shape under cyclic loading. The cyclic stress relaxation and cyclic softening of the bonded butt-joint occur. The increase of mean strain and strain amplitude intensifies the cyclic stress relaxation and cyclic softening behaviors. According to the experimental observation, a nonlinear viscoelastic model is proposed to predict the mechanical behavior of butt-joints under cyclic loading, which considers the cyclic stress relaxation and cyclic softening of the bonded butt-joint. The comparisons between the model calculation and the experimental data show that the calculated stress-strain curve is in good agreement with the experimental data.