CCF300/QY8911层压板破孔损伤快速抢修后的拉伸性能

Tensile properties of rapid repaired CCF300/QY8911 laminates with broken hole damage

针对CCF300/QY8911复合材料层压板破孔损伤抢修后的拉伸强度影响规律和表征方法问题,通过对原始材料标准试件、含预制损伤试件及通过胶接、铆接和胶铆联合修理后试件的拉伸试验,得到了相应的强度、刚度、损伤模式和重点部位应变数据。结果表明,修理部位与原结构刚度不协调是影响修理强度的主要因素;胶接修理具有较高的连接刚度,其修理强度影响因素主要是铺层间结合强度;铆接修理连接刚度较低,且铆钉受单剪容易被拉脱是影响其修理强度的主要因素;胶铆联合修理综合了胶接修理刚度高和铆接修理能防止层间撕裂的双重优势;综合采用胶铆联合湿装配工艺、增加铆钉直径和在工件背面加装防拉脱垫片可显著提高修理效果,其抗拉强度分别为常规铆接修理和常规胶接修理的161.5%和135.9%。所提的基于线弹性断裂理论的强度恢复率评价方法能更好地从整体上表征修理后结构的真实承载能力。

The tensile strength of the CCF300/QY8911 composite laminate after hole damage repair was evaluated using a set of rules and characterization methods.To obtain the necessary data,tensile tests were conducted on standard specimens made from the original material,damaged specimens without repair,and specimens repaired using bonding,riveting,and bonding-riveting joint repair techniques.The corresponding data included strength,stiffness,damage mode,and key point strain.The following conclusions were drawn through comprehensive analysis:the incompatibility between the repair location and the original structure stiffness is the main factor affecting the repair strength;bonding repair has a high connection stiffness,and the main influencing factor of repair strength is the lamina bonding strength;on the other hand,riveting repair,which has a low connection stiffness,is mainly affected by the ease of pulling out the rivet in single shear;bonding-riveting joint repair combines the high stiffness of bonding repair and the dual advantage of riveting repair to prevent interlayer tearing;significantly improving the repair effect by adopting the combined wet assembly process of bonding-riveting,increasing the diameter of rivets,and installing anti-slip pads on the back of the workpiece can achieve a tensile strength of 161.5%and 135.9%higher than the conventional riveting repair and conventional bonding repair,respectively.The method described in this study,which is based on the linear elastic fracture theory,provides a more accurate representation of the real bearing capacity of the restored structure from a comprehensive standpoint.