Finite Element Analyses on Low-velocity Impact Responses of Three-dimensional Braided Composites

Low-velocity impact response and failure mechanism of three-dimensional (3-D) braided composite are investigated both by experiments and finite element analysis method (FEA). A meso-structural FEA model was established. Ductile and shear failure criterions are introduced into the developed model to calculate the impact response and damage evolution under different impact velocities. Five impact velocities of 1 m/s, 2 m/s, 3 m/s, 4 m/s, 6 m/s are applied in this work. The maximum impact load, the displacement at the maximum load and the energy absorbed at the maximum load are obtained from the model. The FE simulations kept in good consistent with experimental results. The results showed that the stress propagation exhibited unique different features along longitudinal, thickness and width direction. In addition, stress concentration regions were appeared at impact locations. Only elastic deformation appeared at impact velocity of 1 m/s, 2 m/s, 3 m/s, 4 m/s. The corresponding thickness displacement increased as velocity increased. Whereas damages were observed on composites and a zigzag damage pattern formed on back surface at impact velocity of 6 m/s.