Xiao Xue, Shanyong Xuan, Bin Fu
State-owned Wuhu Machinery Factory, Wuhu 241007, China.
Heliyon. 2023 Aug 15;9(8):e19143. doi: 10.1016/j.heliyon.2023.e19143. eCollection 2023 Aug.
Impact damage can affect the carrying capacity and service life of aerospace composite structures seriously. In this study, the carbon fiber/epoxy composite (ZT7H/EC3448) was used for scarf bonding repair for CFRP (Z7TH/QY9611) laminates to restore strength. In view of the impact sensitivity of bonding repair of CFRP laminates, a three-dimensional (3D) finite element model (FEM) of the whole damaged response from impact to compression-after-impact (CAI) was established by the subroutine of ABAQUS finite element simulation software. Combined with the experiments of low-velocity impact and compression, the impact damage mode and CAI response of the intact laminates and the wet bonding repaired laminates were evaluated by analyzing the impact response, the failure situation and the residual strength. The results show that the damage of both started in the impacted area and expanded to complete failure in the direction of the vertical fiber. Unlike the intact laminates, the patch of the repaired laminates absorbed a lot of impact energy, which greatly reduced the damage to the original laminates, and the CAI performance for the wet bonding repaired laminates by ZT7H/EC3448 recovered to 97.7% of the intact one.
冲击损伤会严重影响航空航天复合材料结构的承载能力和使用寿命。在本研究中，采用碳纤维/环氧树脂复合材料（ZT7H/EC3448）对碳纤维增强塑料（CFRP）（Z7TH/QY9611）层合板进行斜接修复以恢复强度。鉴于CFRP层合板粘结修复的冲击敏感性，通过ABAQUS有限元模拟软件的子程序建立了从冲击到冲击后压缩（CAI）的整个损伤响应的三维（3D）有限元模型（FEM）。结合低速冲击和压缩试验，通过分析冲击响应、失效情况和残余强度，评估了完整层合板和湿法粘结修复层合板的冲击损伤模式和CAI响应。结果表明，两者的损伤均始于冲击区域，并在垂直纤维方向扩展至完全失效。与完整层合板不同，修复层合板的补片吸收了大量冲击能量，大大减少了对原始层合板的损伤，并且ZT7H/EC3448湿法粘结修复层合板的CAI性能恢复到完整层合板的97.7%。
