Stacking design of uniaxial/biaxial braided composite tube under low-velocity impact load

In this paper, the transverse low-velocity impact behavior of uniaxial and biaxial braided composite tubes is investigated to improve the impact resistance of tubular composite structures and to reveal their energy absorption mechanism. Based on the nonlinear progressive damage model, the finite element method is used for experimental verification and numerical analysis. The composite tubes with different stacking sequences and stacking angles were simulated, and their impact responses were evaluated by the peak load F-max, the maximum indentation depth alpha(max) and the energy absorption EA. The results show that the numerical simulation results are in good agreement with the experimental data, and can accurately capture the failure behavior in the actual scene. The damage mode of the braided composite circular tube under low-velocity impact load is mainly manifested as matrix cracking and interlayer separation, and the expansion direction of the damaged area is basically consistent with the fiber orientation. The impact resistance depends more on the stacking sequence, while the stacking angle is the main factor affecting the energy absorption. Under reasonable design, the uniaxial/biaxial hybrid braided tube can obtain the best low-velocity impact characteristics.