A two-step approach for damage detection in laminated composite structures using modal strain energy method and an improved differential evolution algorithm

The paper presents a two-step approach based on modal strain energy method and an improved differential evolution algorithm for damage detection in laminated composite structures. First, the modal strain energy based method is employed to identify a set of potential damaged elements. Then, the improved differential evolution algorithm is utilized to minimize the function of mode shape error with design variables relating to the extent of identified damaged elements. Here, the function of mode shape error is defined by the shift between the mode shape of the damaged structure and that of the healthy structure. The proposed approach is applied for a cross-ply (0°/90°/0°) laminated composite beam and a cross-ply (0°/90°/0°) square laminated composite plate with multiple damaged elements. In addition, the effect of noise on the accuracy of damage identification is also investigated. Numerical results show that the proposed approach is effective for damage detection in laminated composite beam and plate structures for both cases with noise and without noise.