A damage evolution study of E-glass/epoxy composite under low velocity impact

To predict the behavior of composites in case of low velocity impact, various material models are available in the literature. Damage evolves exponentially or linearly with strain in these models. These models are using either characteristic length 'Lc' or material exponent parameters, 'm' to solve the problem of strain localization. A method to relate these parameter to each other is suggested here. The choice of material exponent, 'm' for a particular mesh size is also discussed. Low velocity impact simulations for E-glass/epoxy composite are performed using continuum damage mechanics based material model and compared with the experiments. The damage observed through the light projected area on the laminate, contact forces and displacement plots with respect to time were studied and compared with finite element analysis results to demonstrate the effectiveness of the model. Digital Image Correlation (DIC) technique is used for experimentation to obtain displacement on the surface of the plate.