Abstract: A novel method (PDA-CZM method) is proposed to predict the damage evolution and residual strength of laminated composites bonded with composite patches. The three-dimensional progressive damage analysis (PDA) and the cohesive zone model (CZM) are used to simulate respectively the damage progression in laminated composites and that in the adhesive layer. The initiation and propagation of fibre damage, matrix cracking, delamination,and adhesive failure of repaired composite laminates as well as the coupling effect among them is investigated. Load-displacement curves and ultimate strengths are obtained by numerical analysis. An excellent agreement is found between the numerical results and the test data, and the validity of the analysis method is proved. Finally, the effect of repair parameters on the residual strength of the repaired laminated composites is discussed.

Key words: laminated composite, repair, damage, cohesive zone model, delamination