The Damage Identification in Laminated Composite Plate under Fatigue Load through Wavelet Packet Energy Curvature Difference Method

In this work, a damage identification framework is presented for Basalt Fiber Reinforced Polymer (BFRP) composite plate systems using the wavelet packet energy curvature difference (WPECD) method. A finite element model (FEM) of the plate is established and an accumulative damage model is introduced to model the plate damage subjected to fatigue, and five damage cases are considered. In the WPECD method for damage identification, dynamic features such as shape models, natural frequencies, and frequency responses is used. To simulate the composite plate damage, four stiffness reduction levels (5%, 10%, 15%, 20%) are employed. The damage can be identified by the WPECD index curve plot, and the influence of the wavelet function and the number of decomposition layers on the damage nodes identification was investigated. The results show that the proposed WPECD index can be identified the low damage levels (i.e. a 5% stiffness reduction). The proposed WPECD index can be employed to effectively identify structural damage.