The strength prediction of adhesive single lap joints exposed to long term loading in a hostile environment

This work is concerned with investigating the residual static strength of adhesively bonded joints after long-term exposure to a combined mechanical-hygro-thermal environment. Associated experimental data are also reported. The degradation process of the joints was modelled using a fully-coupled approach, with the moisture concentration affecting the stress distribution and the stress state affecting the moisture diffusion analyses simultaneously. A bilinear cohesive zone model was then used to implement the progressive damage FE analysis of the quasi-statically loaded joints following the ageing phase. This model is degraded using the damage factors (creep strain and moisture uptake) accumulated over the ageing process and calibrated against the experimental results from static tests on the bulk adhesive. Predicted and experimentally-measured quasi-static responses for the aged adhesive joints were found to be in good agreement.