飞机铆钉孔排布及孔边裂纹对2024-T3铝合金剩余强度的影响

The residual tensile strength (RTS) of 2024-T3 aluminum alloy sheet with rivet holes and cracks in fuselage of aged aircraft was evaluated by using digital image correlation (DIC) technology. Firstly, the effects of row spacing and column spacing on RTS were studied by tensile test. Then, four types of cracks were prefabricated to simulate the multi-site damage phenomenon of aircraft skin, the influence of the change of crack direction on the RTS of samples with staggered holes was analyzed, and the crack growth path was further discussed. Finally, the net section yield criterion was modified. The results show that the RTS increases with the increase of the column spacing. When the column spacing is fixed, the RTS increases with the increase of the row spacing, and when the row spacing is greater than 32 mm, the RTS tends to decrease. The modified net section yield criterion can predict the RTS of the staggered hole structure with multi-site damage, and the prediction error is less than 8%.