基于等效损伤线实验建立的疲劳寿命分析方法

 通过固定一组循环数进行不同应力水平加载试验,用韧性耗散法测得三种材料等效损伤线族,它显示了损伤场全貌。分析得到的损伤线族方程与实验数据拟合很好,由该损伤线族方程导出了复杂加载下损伤累积模型及疲劳寿命计算方法。用该损伤线模型对 3种材料的二级加载试验进行的寿命预测与实验结果较为一致。在等效损伤假设前提下,本文的等效损伤线模型更为直接可信。

EXPLORATION OF FATIGUE LIFE ANALYSIS METHOD BASED ON EQUIVALENT DAMAGE LINE EXPERIMENTS

For three kinds of materials, a family of equivalent damage curve was measured on various stress levels using toughness degradation fatigue tests by fixing a group of cyclic numbers. It displays the materials damage in all the damage field. The mathematical function of the equivalent damage curve family is well fitted with the test data. The damage cumulative model and fatigue life prediction in complex loading were derived from the damage curve family function. The comparison of fatigue test data of two stage loading with prediction of the equivalent damage curve method for three kinds of materials shows good agreement.The fatigue life prediction with the model of the equivalent damage curve is more straight and reasonable if the assumption of equivalent damage exists.