Yang Lei, Huang Xiaolin, Liao Zhenhao, Wei Zongyou, Zou Jianchao
College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China.
Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong SAR 999077, China.
Polymers (Basel). 2024 Sep 12;16(18):2581. doi: 10.3390/polym16182581.
Numerous studies have demonstrated that under low-velocity, low-energy impact conditions, although the surface damage to fiber-reinforced composite laminates may be minimal, significant internal damage can occur. Consequently, a progressive damage finite element model was specifically developed for thermoplastic carbon fiber-reinforced composite laminates subjected to low-speed impact loads, with the objective of analyzing the damage behavior of laminates under impacts of varying energy levels. The model utilizes a three-dimensional Hashin criterion for predicting intralayer damage initiation, with cohesive elements based on bilinear traction-separation law for predicting interlaminar delamination initiation, and incorporates a damage constitutive model based on equivalent displacement to characterize fiber damage evolution, along with the B-K criterion for interlaminar damage evolution. The impact response of laminates at energy levels of 5 J, 10 J, 15 J, 20 J, and 25 J was analyzed through numerical simulation, drop-hammer experiments, and XCT non-destructive testing. The results indicated that the simulation outcomes closely correspond with the experimental findings, with both the predicted peak error and absorbed energy error maintained within a 5% margin, and the trends of the mechanical response curves aligning closely with the experimental data. The damage patterns predicted by the numerical simulations were consistent with the results obtained from XCT scans. The study additionally revealed that the impact damage of the laminates primarily stems from interlaminar delamination and intralayer tensile failure. Initial damage typically presents as internal delamination; hence, enhancing interlaminar bonding performance can significantly augment the overall load-bearing capacity of the laminate.
众多研究表明，在低速、低能量冲击条件下，尽管纤维增强复合材料层压板的表面损伤可能很小，但仍可能发生显著的内部损伤。因此，专门开发了一种渐进损伤有限元模型，用于分析承受低速冲击载荷的热塑性碳纤维增强复合材料层压板的损伤行为，目的是分析不同能量水平冲击下层压板的损伤行为。该模型采用三维Hashin准则预测层内损伤起始，采用基于双线性牵引-分离定律的粘结单元预测层间分层起始，并结合基于等效位移的损伤本构模型来表征纤维损伤演化，以及用于层间损伤演化的B-K准则。通过数值模拟、落锤试验和XCT无损检测，分析了能量水平为5J、10J、15J、20J和25J时层压板的冲击响应。结果表明，模拟结果与实验结果密切相关，预测的峰值误差和吸收能量误差均保持在5%以内，力学响应曲线的趋势与实验数据紧密吻合。数值模拟预测的损伤模式与XCT扫描结果一致。该研究还表明，层压板的冲击损伤主要源于层间分层和层内拉伸破坏。初始损伤通常表现为内部分层；因此，提高层间粘结性能可显著提高层压板的整体承载能力。
