含MSD铝合金平板的剩余强度试验研究

针对飞机结构中日趋显著的多部位损伤(MSD)问题,进行含多部位损伤铝合金平板结构剩余强度的试验研究.试验中使用三种不同的试验件,将其在相同应力水平下预制出一定长度的多条裂纹后拉断,记录断裂时的载荷.试验结果与常用的五种评估含多裂纹结构失效准则进行计算分析和对比,了解各个准则的准确程度.最后的对比表明,五种估算剩余强度的方法中,净截面失效和裂纹尖端张开位移法误差较大,断裂力学估算方法对于有显著主裂纹的情况更适用,塑性区连通和平均应力准则预测的偏差较小.

Test Research of Residual Strength on Aluminum Panels with Multiple Site Damage

Tests of residual strength on aluminum panels with multiple site damage(MSD)were conducted.Three different kinds of typical specimens were used,which had multiple cracks under the same stress level.The failure load was recorded when the test specimens were broken.Five different failure criterions were used to predict the failure load,and the predict results were compared with the test results in order to study the validity of these failure criterions.The results indicate that the Swift and average stress criterion can give better results than net ligament loss,CTOD criterion and the fracture mechanics criterion.