An interlaminar damage shell model for typical composite structures

Using the plate/shell elements in commercial software, accurate analysis of interlaminar initial damage in typical composite structures is still a challenging issue. To propose an accurate and efficient model for analysis of interlaminar initial damage, the following work is carried out: (A) A higher-order theory is firstly proposed by introducing the local Legendre polynomials, and then a novel shell element containing initial damage prediction is developed, which can directly predict transverse shear stresses without any postprocessing methods. Unknown variables at each node are independent of number of layers, so the proposed model is more efficient than the 3D-FEM. (B) Compression experiment is carried out to verify the capability of the proposed model. The results obtained from the proposed model are in good agreement with experimental data. (C) Several examples have been analyzed to further assess the capability of the proposed model by comparing to the 3D-FEM results. Moreover, accuracy and efficiency have been evaluated in different damage criterion by comparing with the selected models. The numerical results show that the proposed model can well predict the initial interlaminar damage as well as other damage. Finally, the model is implemented with UEL subroutine, so that the present approach can be readily utilized to analyze the initial damage in typical composite structures.