摘要
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。
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 method, high temperature fatigue lives are well predicted for specimens with different notch radiuses. As to multi-step loading condition, cyclic deformation behavior is investigated for 316L steel and creep-fatigue interaction coupled with dynamic strain aging effect is also discussed. Based on the ductility exhaustion theory, a nonlinear damage evolution model is developed. Moreover, a new damage cumulated rule is proposed with the load history effect taken into account. By using this model, 2-step creep-fatigue lives are well predicted.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第2期81-87,共7页
Journal of Mechanical Engineering
基金
"十一五"国家科技支撑计划专题(2006BAK02B02-02)
安徽省优秀青年基金(08040106827)资助项目
关键词
多轴
多级
疲劳蠕变
损伤
寿命预测
Multi-axis Multi-step Creep-fatigue Damage Life prediction
