Stress intensity factor for repaired crack with bonded composite patch under thermo-mechanical loading

In this study, the finite element method is used to analyze the effect of the thermal residual stresses resulting from adhesive curing on the performances of the bonded composite repair in aircraft structures. The stress intensity factor at the crack tip is chosen as the fracture criterion in order to estimate the repair performances. The effects of the curing temperature, the geometrical properties of the patch, and the adhesive properties on the variation of the stress intensity factor are analyzed. The obtained results show a significant negative effect of the thermal residual stresses on the repair efficiency and this effect can be reduced if the different repair parameters are optimized.