Low-velocity impact and compression after impact behaviors of rib-stiffened CFRP panels: Experimental and numerical study

This study aims to experimentally and numerically study the low-velocity impact (LVI) and compression after impact (CAI) behaviors of rib-stiffened CFRP panels. Experimental LVI tests have been initially performed on T- and I-shaped rib-stiffened panels. CAI tests are subsequently implemented on the impacted and intact panels. Furthermore, multiscale models are established according to the hierarchical architectures of plain woven composites. An equivalent cross-ply laminate (ECPL) cell has been constructed via local homogenization on the mesoscale modeling. The ECPL cells are topologically arranged to form macroscale models of the rib-stiffened panels. LVI and CAI simulations have been sequentially carried out to predict the LVI and CAI behaviors. The predicted results possess good agreement with the experimental ones, validating the multiscale models. Matrix damages and delamination are found to be the dominant damage modes for the rib-stiffened panels subjected to LVIs. In comparison, the I-shaped stiffener makes CFRP panel more sensitive to impact loads. During the CAI processes, fierce fiber breakage, matrix cracking and delamination appear in the skin and stiffener. Finally, the comparison of CAI strengths indicates that, the I-shaped stiffener provides CFRP panels with a better resistance to the compressive-property reduction induced by LVIs.