| A strategy for detecting delamination of composite laminates is proposed in this paper, which is based on dynamic finite element method in conjunction of Wavelet Analysis and Neural Networks scheme. Because of the special performance of composite laminates, various forms of damage will appear, this damage will cause the infirmness of the carrying capacity of the structure. Firstly, the current damage detecting approaches have been reviewed. Then, by introducing some basic theory and interrelated conclusions of the Wavelet Analysis and Neural Networks scheme, their advantages and disadvantages are summarized, hence the reasons relating their applicability to damage evaluation could be obviously concluded. Then a dynamic finite element method is developed for the composite laminates with through-width delamination, and the boundary condition of the composite laminates is one side clamped. From the typical examination it can be show that the dynamic finite element method in this paper is reliable. Using Wavelet Analysis, the damage moment could be obviously seen by decomposition of the signals, and the delamination located in different location along the beam with different size could be detected in conjunction with bending modal of the structure. And, all the delaminations of the composite beam could also be detected when the beam is suffering Multi-delaminations. According to the discussion of the input parameter, and the analyse of influences of the length and location of delamination upon the natural frequency, the stylebook for the training of the Neural Network is founded. At last back propagation (BP) neural network in the Toolbox of MATLAB software is established for training and testing the network. From the simulating results it can be shown that present strategy is efficient for detecting delamination of the composite laminates. The research is supported by NSF -Nonlinear Dynamic and Failure Behavior of Stiffened Composite Plate and Shell (10272025)...
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