复杂载荷下疲劳寿命估算  

FATIGUE LIFE ESTIMATION UNDER COMPLEX LOADING

作　　者：田丁拴 吴富民[2] 

机构地区：[1]飞行试验研究院 [2]西北工业大学

出　　处：《航空学报》1991年第2期B079-B086,共8页Acta Aeronautica et Astronautica Sinica

摘　　要：本文给出了LY12CZ铝合金板材的循环硬化规律;以材料在循环载荷作用下累积的塑性滞后能作为疲劳损伤准则,证明了应力控制等幅循环加载条件下损伤累积随循环次数变化的非线性,导出了材料瞬态塑性应变能的计算公式,算出了破坏发生时材料耗散的总塑性应变能,并给出了它与应力变程的关系。文中把疲劳损伤分为静拉伸损伤与循环损伤两部分,给出了损伤累积模型。以该模型为基础,计算了两级加载、4级加载和程序加载下光滑试件的疲劳寿命。计算结果与试验结果符合很好。The cyclic property of aluminium alloy sheet LY12-CZ is given quantitatively. Accumulated plastic hysteresis energy under cyclic loading is taken as damage criterion. Nonlinearity of damage accumulation with cycle number under cyclic loading is proven. The formula used to calculate instantaneous plastic strain energy is derived. The total dissipated plastic strain energy for the whole life period is calculated and its variation with stress range is shown. Fatigue damage is separated into two parts-static tension damage and cyclic damage. With the help of above analysis, a fatigue life estimation model is presented. Fatigue life estimations with the model of two stress level, four stress level and programed loading are completed. Comparison are made between calculated fatigue lives and the corresponding experimental data and the agreements are satisfactory.

关 键 词：疲劳损伤 疲劳寿命 飞机 循环硬化 

分 类 号：V215.51[航空宇航科学与技术—航空宇航推进理论与工程]