复杂加载条件下压力容器典型用钢疲劳蠕变寿命预测方法

针对多轴应力状态,探讨压力容器典型用钢16MnR缺口试样的高温疲劳与循环蠕变交互作用行为,在延性耗竭理论和损伤力学基础上,建立一种半寿命平均位移速率寿命预测模型,采用该方法对不同缺口半径试样的高温疲劳寿命进行了较好的预测.针对多级加载条件,研究316L钢的循环变形行为,探讨疲劳蠕变与动态应变时效之间的耦合作用,在延性耗竭理论基础上,建立非线性损伤演化模型,考虑多级加载时的载荷历程效应,提出一种新的损伤累积准则,采用该方法对二级加载条件下的疲劳蠕变寿命进行了较好的预测.

Creep-fatigue Life Prediction Methods of Pressure Vessel Typical Steels under Complicated Loading Conditions

With emphasis on complicated loading conditions,i.e.multi-axial loading condition and multi-step loading condition,creep-fatigue behavior and life prediction methods are investigated for typical steels of pressure vessels.As to multi-axial loading condition,the interaction behavior between high temperature fatigue and cyclic creep is discussed for 16MnR notched specimens and a mean displacement rate life prediction method is proposed on the basis of ductility exhaustion theory and damage mechanics.By this m...