Comparison of low-velocity impact behavior of thick laminated composite structure with experimental and modeling technique

Abstract

In this study, the dynamic behavior under low-veloctiy impact of E-glass epoxy unidirectional thick laminated composite structure was investigated by numerical methods and compared with experimental results. Thereby, it was aimed to detect the impact behavior of the composite structures with numerical analysis program for reducing experimental tests on these composite structures. LS-DYNA finite element method (FEM) software was used for numerical modeling. The material model MAT055, which is based on the Tsai–Wu matrix failure modeling on damage mechanics, was selected for the analyses in LS-DYNA. Low-velocity impact analyses have been carried out on composite structures at various impact energies as a range of 15–250 J as similar to experiments. From the analysis of the plots, it can be seen that the values of absorption energy provided by the FEM analyses are close to the experimental values at all impact energy levels. It can be determined that the mean difference between the absorption energy levels provided from the experimental and numerical studies is 1.81%. In the same studies, matrix cracking was observed at 50 J impact energy value and full penetration was observed at 250 J impact energy. The error rate between the values obtained using the derived impact energy prediction equation and the values obtained as a result of numerical analysis was maximum 5.26%. Thus, derived equation was found to be reasonable for use in predicting the absorption energy. As a result, these values indicate that the experimental results are agreed well with the numerical results. Highlights: Dynamic behavior under impact of thick laminated composite was investigated. Impact analyses were performed at impact energies as a range of 15–250 J. At 250 J impact energy, the composite deformed with full penetration damage. Impact damage areas were calculated according to impact energy levels. It would be useful to use numerical analysis method in terms of cost and time.