一种随机多轴疲劳的寿命预测方法

叙述一种多轴随机载荷的疲劳寿命预测方法，该方法首先由多轴随机载荷的权值平均最大剪应变平面确定临界平面，然后以临界平面上剪应变和正应变历史为研究对象，进行多轴载荷压缩处理和多轴循环计数，得到剪应变和正应变的循环计数结果，最后给出多轴疲劳寿命估算模型，并用多轴程序载荷实验验证。

LIFE PREDICTION APPROACH FOR RANDOM MULTIAXIAL FATIGUE

According to the concept of critical plane, a life prediction approach for random multiaxial fatigue is presented. Firstly the critical plane under multiaxial random loading is determined based on the concept of the weight-averaged maximum shear strain directions. Then multiaxial load reducing and multiaxial cycle counting methods are applied to deal with and count the calculated shear and normal strain histories on the critical plane. Furthermore, a multiaxial fatigue life prediction model including the parameters resulted from multiaxial cycle counting is presented and applied to calculating the fatigue damage generated from each cycle. Finally, the cumulative damage is added up using Miner's linear rule, and the fatigue prediction life is obtained. The experiments under multiaxial loading blocks are used for the verification of the proposed method. The prediction has a good correction with the experimental results.