Impact Behavior and Damage Mechanisms of CFRP Laminates Containing Manufacturing‐Induced Delamination Defects

ABSTRACT Manufacturing‐induced defects are unavoidable for carbon fiber‐reinforced polymer (CFRP) laminates. Whether to discard defective CFRP components or continue their utilization presents a complex dilemma for engineers, as it involves a critical trade‐off between cost‐effectiveness and safety considerations. To address this, the impact behaviors of CFRP with and without delamination defects are investigated, combining experimental and numerical methods. The influences of defect size and positions are also analyzed. An in‐depth analysis of damage modes, including matrix cracking, fiber damage, and delamination, and the corresponding energy dissipation by each mode is investigated to reveal the underlying reasons behind the changes in impact resistance. Furthermore, the effect of the number of interfaces containing defects and off‐center impacts on the mechanical behavior and damage mechanisms of CFRP laminates is discussed by the validated finite element models. The results show that with the increase of defect area and layer numbers, matrix cracking and fiber damage are more serious when the laminates are impacted. Surprisingly, the toughness of CFRP laminates seems to be enhanced as the total dissipated energy is reduced by the introduction of defects. The contribution of this work is to reveal insights into the impact behavior of CFRP containing defects.