Experiment studies and fem simulation of repaired composite laminates

The compressive experiments and the corresponding finite element modeling were studied for the repaired composite laminates under compressive static load to evaluate the efficiency of repaired panels. The geometric non-linear and linear methods were applied to compute the stress-strain response of the repaired and the unrepaired laminates. The finite element models were analyzed with the three-dimensional S8R shell elements. The non-linear geometry effect was incorporated in the present analysis, and the user material subroutine (UMAT) was programmed to predict the damage initiation and its progression. The predicted strain distribution, damage evolution and strength of the laminates are verified with the experimental results.