摘要
为了预测锅炉、压力容器的整体寿命,用连续介质损伤力学理论研究了工程材料的低周疲劳损伤演变过程.采用循环应力幅定义损伤变量D,根据有效应力概念,建立了低周疲劳各向同性连续损伤模型,并通过控制应变的疲劳试验,用该模型对锅炉常用材料12Cr1MoV钢试件进行了疲劳损伤的测量.研究表明,当循环进行到80%寿命时,损伤进入局部化阶段,宏观裂纹开始形成,较好地验证了损伤演变模型;所建立的模型形式简单,参数少,易测量,具有明确的物理意义,对锅炉的寿命估算有参考价值.
The equipment, such as boiler, pressure vessel and pipeline, subjected to cyclical load suffer failure as a result of the low cycle fatigue( LCF) . In this paper,the LCF damage evolution of the engineering materials is studied by use of continuum damage mechanics theory. A new fatigue damage variable D based on the cycling stress amplitude is defined. A continuum damage model of isotropic LCF is derived and is used to analyze the strain-controlled LCF damage evolution of boiler material 12CrlMoV steel. During strain-controlled LCF tests to verify the model, which is in good agreement with the results. The research results show that the parameters in the model have clear physical meaning and can easily be determined. It will provide an effective means for the boiler's life estimate.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2005年第2期193-195,共3页
Materials Science and Technology
关键词
低周疲劳
损伤力学
损伤变量
损伤演化
low cycle
damage mechanics
damage variable
damage development
