Abstract: Based on the dynamic finite element method in conjunction of neural networks,a strategy for detecting delamination of composite laminates was proposed.To establish the data-base for neural networks,a nonlinear dynamic finite element method,developed by the authors,was used to calculate the values of natural frequencies and mode damping of the delaminated composite plates,while a back propagation ( BP) neural network was employed for training and testing the network.The typical simulating results show that the high order mode damping is better than frequencies as an input parameter for detecting delamination damage,because the former is more sensitive to the extent of delamination.The present strategy is an effective and low cost method for detecting delamination of the composite laminates.