Low‐velocity impact response and damage tolerance of hybrid biaxial/triaxial braided composite laminates

The structural properties of braided composite laminates are significantly affected by the low-velocity impact (LVI). In this paper, resistance and damage tolerance triaxial braid structure at different positions were mainly studied. Three hybrid biaxial (B)/triaxial (T) structures BBTT, BTTB, TTBB designed, LVI test post-impact compression tests carried out. results show that fabric with quasi-isotropic on side caused more significant matrix cracks along axis yarn direction, area delamination larger. For ply high curl levels, severe fiber fracture relatively concentrated occurred first non-impact side. Interestingly, fabrics exhibited better in terms mechanical response when distributed across specimen surface. However, a global pattern appears energy which seriously reduced residual strength showed worst tolerance. quantification analysis cracks, dent depths, compressive shaft number was out work, provided valuable reference for engineering failure rational optimization laminates.