2E12铝合金机身壁板损伤容限分析与试验验证

Analysis and Test Verification of Damage Tolerance of 2E12 Aluminum Alloy Fuselage Panel

2E12为国产新研铝合金材料,拟用于飞机机身蒙皮结构。损伤容限特性是该材料应用于型号的关键指标之一。按损伤容限设计要求,本文设计了3组典型的机身壁板结构试验件,包含了单跨裂纹、双跨裂纹和裂纹修理3种情况,首先完成了裂纹扩展和剩余强度数值分析,随后进行了验证试验,同时与2024铝合金试验件进行了对比分析和试验。研究结果表明:新研2E12铝合金材料损伤容限性能较好,能够满足型号设计要求;相对于单裂纹扩展,多裂纹的存在显著提高了裂纹扩展速率,多裂纹的总寿命缩短约为30%;裂纹扩展分析结果与试验结果误差小于10%;各试验件剩余强度结果一致性很好,分析结果与试验结果的差别约为2.3%。

2E12 is a new aluminum alloy material made in China. It is to be used in aircraft fuselage skin structure. Damage tolerance performance is one of its key indicators for the material. According to the requirement of damage tolerance design, this paper designs three typical test pieces of fuselage panel structure, including single-span crack, double-span crack and crack repair. Firstly, the numerical analysis of crack propagation and residual strength is completed, and then the verification test is carried out. The results are compared with those of 2024 aluminum alloy. The results show that the damage tolerance of 2E12aluminum alloy material can meet the design requirements. Compared with single crack propagation, the existence of multi-crack increases the crack growth rate significantly, and the total life of multi-cracks is shortened by about 30%. The error of crack propagation analysis and test results is less than 10%. The residual strengths of all test pieces are in good agreement, and the difference between the analytical results and the experimental results is about 2.3%.