【摘要】 多处损伤(MSD)是老龄飞机关注的焦点之一。提出了计算多处损伤铝合金加筋板的应力强度因子的工程方法。用工程方法和有限元方法分别计算了多处损伤铝合金加筋板的剩余强度,进行了三种类型9件铝合金加筋板的剩余强度试验。主裂纹和多裂纹用钼丝切割制备。估算结果与试验结果具有良好的一致性,满足工程精度要求。结果还表明,MSD明显降低了加筋板的剩余强度。更多还原

【Abstract】 Experimental and analytical investigations on the residual strength of the stiffened LY12CZ aluminum alloy panels with widespread fatigue damage (WFD) are conducted. Nine stiffened LY12CZ aluminum alloy panels with three different types of damage are tested for residual strength. Each specimen is pre-cracked at rivet holes by saw cuts and subjected to a monotonically increasing tensile load until failure is occurred and the failure load is recorded. The stress intensity factors at the tips of the lead crack and the adjacent WFD cracks of the stiffened aluminum alloy panels are calculated by compounding approach and finite element method (FEM) respectively. The residual strength of the stiffened panels with WFD is evaluated by the engineering method with plastic zone linkup criterion and the FEM with apparent fracture toughness criterion respectively. The predicted residual strength agrees well with the experiment results. It indicates that in engineering practice these methods can be used for residual strength evaluation with the acceptable accuracy. It can be seen from this research that WFD can significantly reduce the residual strength and the critical crack length of the stiffened panels with WFD. The effect of WFD crack length on residual strength is also studied.更多还原