In this study, we analyzed the effect of a single overload fatigue cycle on the efficiency of bonded composite patch repair on a cracked Al 2024 T3 aluminum plate. Experimental and numerical analyses were performed to achieve the objective of the study. In the experimental part of the study, fatigue tests were conducted on a V-notched aluminum plate subjected to a constant amplitude fatigue loading with an overload applied at a relative crack length of 0.06 (a/W = 0.06). The plate was repaired with a carbon/epoxy composite patch. A fatigue life curve (a = f(N)) was plotted for the patched and unpatched specimens using the results of the experimental tests, and scanning electron microscopy images of the fracture surfaces of the failed specimens were observed. In the numerical part, the elastic–plastic finite element method was used to evaluate the plasticity induced by the overload on the patched plate and to analyze the adhesive damage after this overload was applied. The obtained results demonstrate that the patch deposition of the overload can lead to an extended fatigue life, and the adhesive damage after the overload is quite significant, but the risk of total failure of the adhesive layer is not high.

在本研究中，我们分析了单个过载疲劳循环对裂纹 Al 2024 T3 铝板粘合复合补片修复效率的影响。进行了实验和数值分析以实现研究的目标。在研究的实验部分，对V型缺口铝板进行了恒幅疲劳加载，并在相对裂纹长度为0.06（a / W  = 0.06）处施加过载。该板用碳/环氧树脂复合材料补片修复。疲劳寿命曲线 ( a  =  f ( N)) 使用实验测试结果绘制修补和未修补试样，并观察失效试样断口的扫描电子显微镜图像。在数值部分，采用弹塑性有限元方法评估修补板上过载引起的塑性，并分析施加过载后的粘附损伤。得到的结果表明，过载的贴片沉积可以延长疲劳寿命，过载后的胶粘剂损伤相当显着，但胶粘层完全失效的风险不高。