基于等效应变的轮盘低循环疲劳寿命预测

针对轮盘低循环疲劳载荷非对称及其主要寿命区限,提出一种简化的等效应变寿命预测模型,对某型发动机高压压气机I级盘进行了低循环疲劳寿命预测。补充了1Cr11Ni2W2MoV材料轴向应变控制的低循环疲劳试样试验,设计了高压压气机I级盘低循环疲劳试验件,在旋转试验器上进行了轮盘的低循环疲劳试验,得到3个盘的平均低循环疲劳试验寿命为4 280个试验循环。通过与试验寿命的比较,等效应变寿命预测误差为41.8％,Manson-Coffin预测误差为99.2％。结果表明:简化的等效应变寿命预测方法是有效的,而且对试验盘的寿命预测精度比Manson-Coffin预测模型高。

Disk Low Cycle Fatigue Life Prediction Based on Equivalent Strain

A simplified equivalent strain model is presented to predict the disk Low Cycle Fatigue (LCF) life aimed at unsymmetrical loads and the main life regions. Using this model, the LCF life of the first high-pressure compressor disk is predicted. A series of axial strain-controlled LCF tests of 1Cr11Ni2W2MoV bar specimens are conducted. Then an experimental disk is designed, and the LCF test of the rotor is carried out on the spin test rig. The average LCF test life of three disks, 4 280 test cycles, is obtained. Compared with the test life, the prediction error of equivalent strain model is 41.8%, and that of Manson-Coffin model is 99.2% .The result indicates that the disk LCF life prediction method based on the equivalent strain is effective, and is higher than the Manson-Coffin method in accuracy of life prediction.