Finite element modeling of CFRP composite tubes under low velocity axial impact

Abstract The dynamic axial crushing response of circular tubes made of unidirectional carbon fiber‐epoxy composite was investigated numerically applying a new approach to the modeling of the delamination process. In the proposed approach, delamination (interface damage) was modeled by inserting isotropic resin plies capable of damage. They are tied to the adjacent laminae and replace the commonly used surface‐based cohesive model. Two multi‐layer models of laminated tubes having cross‐ply and angle‐ply stacking sequences were simulated using stacked conventional shell elements layers to capture the crushing response and intralaminar and interlayer damage of laminated tubes. The progressive failure analysis in Abaqus/Explicit was utilized to model the successive damage of both the interface and laminae. Both the intralaminar layers and isotropic resin layers were modeled by the conventional reduced integration shell element (S4R). The suggested modeling technique offers some advantages compared to the main‐stream interface modeling of the axial impact of laminated tubes. The computational cost is reduced and yet accurate predictions are obtained. The FE models based on the proposed delamination approach were validated by experimental test results obtained by the authors for cross‐ply and angle‐ply tubes subjected to a low‐velocity impact.