单螺栓修复对含冲击损伤碳纤维/环氧树脂复合材料层合板压缩承载能力的影响

开展了单钉修复对含冲击损伤碳纤维/环氧树脂复合材料层合板压缩承载能力影响的试验研究。测试了三种不同能量冲击后碳纤维/环氧树脂复合材料层合板的压缩承载能力及失效模式，测定了单螺栓对碳纤维/环氧树脂复合材料层合板压缩承载能力的修复效率，并借助数字图像相关技术(DIC)表征手段揭示了单螺栓修复对含冲击损伤结构失效行为的影响。结果表明:冲击后碳纤维/环氧树脂复合材料层合板的压缩承载能力随着冲击能量的增加而降低，冲击损伤破坏了碳纤维/环氧树脂复合材料层合板结构的对称性，并导致结构在加载初期呈非对称的局部屈曲变形特征，局部屈曲诱发并加剧分层损伤扩展；单螺栓修复能有效恢复结构的整体对称性，在一定程度上抑制含冲击损伤碳纤维/环氧树脂复合材料层合板的局部屈曲，达到可观的修复效率。该研究为复合材料紧固件修理方案的制订及修理损伤容限的定义提供一定的指导意义。 

Effect of single-bolt repair on compression capability of carbon/epoxy composite laminates containing impact damage

The efficiency of single-bolt repairing on the compression capacity of carbon/epoxy composite laminates containing impact damages was experimentally reported. The compression bearing capacity and failure modes of carbon/epoxy composite laminates with impact damage under three different level energies were studied. Simultaneously the efficiency of single bolt repairing on the compression capacity of the above-mentioned impacted carbon/epoxy composite laminates was investigated together with failure behavior based on digital image correlation (DIC) technology. The results show that the compressive load capacity of the laminated plate decreases with the increase of the impact energy, and the impact damage destroys the stiffness symmetry of the carbon/epoxy composite laminates, resulting in asymmetric local buckling deformation from the initial stage of loading. Bolt repairing can restore the overall symmetry of the carbon/epoxy composite laminates, inhibit the local buckling of the delaminated area to a certain extent, and improve considerable repair efficiency. This work is helpful for the decision of fasten repairing strategy and the definition of repair damage tolerance for composites structure.