Abstract:
In order to study the effect of thermal residual stress on fatigue life of double-side adhesively bonded composite repairs to damaged metallic plate, LY12CZ aluminum alloy plate containing crack was adhesively bonded with E300/E51 composite patches in two-sides, and the fatigue life of the repaired structure was studied; The crack growth was also investigated from the fracture surface analysis. Simultaneously, the 3-D finite element model with respect of thermal stress effects was built by Abaqus software, and the relations between stress intensity factor (SIF) and crack length were also been calculated by the finite element model. Meanwhile, the relationship between the SIF amplitude and crack length also was got by quadratic polynomials fitting. At last, the materials constant correction method of Pairs law was applied for the fatigue life prediction of the repaired structure. The results indicate that, under the same fatigue load conditions, the fatigue life of cracked plate repaired structure was 23 times as great as unrepaired cracked plate; SIF increased with the increase of thermal residual stress; the fatigue life of cracked plate repaired structure, which was predicted by finite element model, was in good agreement with the experimental result, and the relative error was 3.7%.