摘要
应力控制模式下出现的循环蠕变现象,将和疲劳一起加速材料的损伤.在进行损伤评估的时候,需兼顾循环蠕变和疲劳的影响.在循环蠕变本构模型、延性耗散理论的基础上,建立循环蠕变疲劳交互作用损伤力学模型.进行16 MnR钢420℃下应力控制的脉动循环试验,选取一种新的损伤参量“等效模量”来描述循环蠕变和疲劳的综合作用,得到16 MnR钢420℃脉动循环时循环蠕变疲劳交互作用下的损伤演化估算表达式和寿命预测方法.通过试验验证,寿命预测结果与试验结果吻合较好.
Cyclic creep under stress control condition with non-zero mean stress will interact with fatigue to accelerate the damage process, resulting in a shorter cyclic life. Based on the cyclic creep constitutive model and the ductility exhaustion theory, a new fatigue and cyclic creep interaction CDM model is proposed. A series of pulsating cyclic tests of 16 MnR under stress control at 420 ℃ were carried out, and equivalent modulus is selected to define the damage variable, whose monotonic and irreversible decline can reflect both damage of cyclic creep and fatigue. The damage evolution equation and life prediction method of 16 MnR steel subjected to interaction between cyclic creep and fatigue at 420 ℃ are given. It＇ s found that the prediction agrees well with the test results.
出处
《固体力学学报》
CAS
CSCD
北大核心
2006年第1期65-70,共6页
Chinese Journal of Solid Mechanics
基金
国家"十五"科技攻关专题(2004BA803B02-06)
国家社会公益基金(2004DIB2J051)
安徽省自然科学基金(050450405)资助
关键词
连续损伤力学
循环蠕变
疲劳
中温
应力控制
continuous damage mechanics（ CDM）, cyclic creep, fatigue, elevated temperature, stress control
