压力容器低周疲劳寿命的损伤力学理论研究

THE INVESTIGATION OF LOW-CYCLE FATIGUE LIFE FOR PRESSURE VESSEL BY DAMAGE MECHANICS APPROACH

采用材料延性指标（断面收缩率ψ）定义了一种疲劳损伤变量Ｄψ，并将该损伤变量应用于１６ＭｎＲ压力容器用钢疲劳损伤的研究，提出了一种新的压力容器低周疲劳寿命预测的损伤力学理论，研究结果表明，本文建立的损伤力学方法比局部应力应变法更接近实验结果。

A new fatigue damage variable Dψ based on the material ductility property-reduction ofcross sectional area at fracture is defined. And the new damage variable is applied to studythe fatigue damage of 16MnR pressure vessel steel. Damage evolution equations of weldmetal,heat-affected zone and base metal are established respectively.A damage mechanicstheory for studying the low-cycle fatigue life of pressure vessel is presented.The research re-sults show that the predicted values of fatigue life from the damage mechanics approach pre-sented by the author are in better agreement with experimental data than the calculated datafrom local stress-strain approach.