Liu Bangxiong, Lai Jiamei, Liu Hesheng, Huang Zhichao, Liu Bin, Peng Ze, Zhang Wei
Polymer Processing Research Laboratory, School of Advanced Manufacturing, Nanchang University, Nanchang 330031, China.
School of Mechanical and Electronic Engineering, Jingdezhen University, Jingdezhen 333400, China.
Polymers (Basel). 2023 May 27;15(11):2484. doi: 10.3390/polym15112484.
Composite laminates are susceptible to impact events during use and maintenance, affecting their safety performance. Edge-on impact is a more significant threat to laminates than central impact. In this work, the edge-on impact damage mechanism and residual strength in compression were investigated using experimental and simulation methods by considering variations in impact energy, stitching, and stitching density. The damage to the composite laminate after edge-on impact was detected in the test by visual inspection, electron microscopic observation, and X-ray computed tomography techniques. The fiber and matrix damage were determined according to the Hashin stress criterion, while the cohesive element was used to simulate the interlaminar damage. An improved Camanho nonlinear stiffness discount was proposed to describe the stiffness degradation of the material. The numerical prediction results matched well with the experimental values. The findings show that the stitching technique could improve the damage tolerance and residual strength of the laminate. It can also effectively inhibit crack expansion, and the effect increases with increasing suture density.
复合材料层压板在使用和维护过程中容易受到冲击事件的影响，从而影响其安全性能。与中心冲击相比，边缘冲击对层压板的威胁更大。在这项工作中，通过考虑冲击能量、缝合和缝合密度的变化，采用实验和模拟方法研究了边缘冲击损伤机制和压缩残余强度。通过目视检查、电子显微镜观察和X射线计算机断层扫描技术在试验中检测边缘冲击后复合材料层压板的损伤。根据Hashin应力准则确定纤维和基体损伤，同时使用粘结单元模拟层间损伤。提出了一种改进的Camanho非线性刚度折减方法来描述材料的刚度退化。数值预测结果与实验值吻合良好。研究结果表明，缝合技术可以提高层压板的损伤容限和残余强度。它还可以有效地抑制裂纹扩展，并且随着缝合密度的增加效果增强。
