Modified Subcell Model Using Solid Elements for Triaxial Braided Composite under Ballistic Impact

In this paper, a modified laminated finite-element model based on subcell of unit cell and CDM material model was developed in nonlinear explicit finite-element code to investigate the dynamic response of 2D triaxial braided composite under ballistic impact of projectile. Six subcells, which were considered as laminate with different stacking sequences using solid elements, were employed to represent one unit cell of triaxial braided composites, therefore, the fiber-laying direction of braiding architecture is reproduced. In the prediction of the subcell model, an approximate round conical deformation area forms in the target and the failure modes are mainly longitudinal and transverse cracking due to tension. Compared with the continuum model, the subcell model is capable of analyzing the energy absorption of fiber in each direction. Although the failure modes are similar for both methods, the subcell model is more effective in prediction of impact wave propagation than the continuum model because it describes the fiber arrangement of triaxial braided composites. The developed subcell model will be an effective tool for the design process of carbon/epoxy composite fan casings.