开孔圆柱壳模拟疲劳试验模型及加载条件的研究

研究受内压开孔圆柱壳与其受拉伸开孔平板模型在结构和受载条件上的相似性，有限元分析表明，开孔圆柱壳与其相应的平板模型在开孔附近的等效应力分布非常相似，分析和试验结果表明，开孔圆柱壳模拟疲劳试验载荷应由控制疲劳寿命的关键部位（即危险点）的等效应力来确定，当开孔圆柱壳与其平板模型在危害点的等效应力水平和分布相同时，可认为二者的疲劳寿命也相同，在正确的加载条件下，开孔平板模型可用于开孔圆柱壳的模拟疲劳试验，并较精确地预测开孔圆柱壳的疲劳寿命。

MODEL AND LOADING CONDITIONS FOR MODAL FATIGUE TEST OF CYLINDRICAL SHELL WITH A HOLE

The similarities of structure and loading conditions of a cylindrical shell with a hole under inside pressure and that of its plate model(a plate with a hole under tension) are analyzed to improve the precision of its fatigue life prediction by modeling. The similarity between equivalent stress distribution around the holes in cylindrical shell and its plate model is shown through finite element analysis. Analysis and test results reveal that the modal fatigue test load on the plate model should be determined by the equivalent stress at the hot spots that determine the fatigue lives of the cylindrical shell and its plate model. If the equivalent stress levels and distributions at hot spots of the cylindrical shell and its plate model are equal, their fatigue lives will be considered equal too. The plate model can be used to conduct modal fatigue tests of the cylindrical shell and precisely predict its fatigue life under correct loading conditions.