摘要
以连续损伤力学(CDM)的经典损伤理论为基础,对疲劳、蠕变及其交互作用下的损伤演化分别进行了研究,进而推导出一个新的疲劳-蠕变交互作用的损伤模型．为将上述模型方便的运用于工程实际之中,通过1．25Cr0．5Mo钢光滑试样540℃环境下应力控制的梯形波加载实验,对工程中容易测量的轴向变形即平均应变的变化规律进行了研究,选取平均应变的变化作为损伤变量,用上述模型进行了1．25Cr0．5Mo钢光滑试样540℃下的疲劳-蠕变交互作用的损伤描述,结果表明实验损伤点与该模型的损伤演化规律符合较好．在上述模型和平均应变变化规律的基础上,对工程上如何进行失效判定进行了相应的探讨．
Based on the continuum damage mechanics, a new damage model has been developed for fatigue-creep interaction. In order to apply this model to the practical engineering condition, fatigue-creep interaction experiments of cylindrical specimens of steel 1.25Cr0.5Mo have been carried out to research the damage evolution at 540 ℃ under stress control, using a trapezium waveform with the hold-time per cycle. According to the experiments, the changing rule of mean strain has been studied and the change of mean strain is defined as the damage variable. Damage curves of different stress ranges have been obtained based on the above damage model. Results show that the values of damage calculated from the damage variable agree well with these damage curves. Based on the damage model and the change rules of mean strain, the failure assessment in engineering is also discussed, and a method to prevent the rupture of engineering components has been proposed.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第6期637-642,共6页
Acta Metallurgica Sinica
基金
国家十五科技攻关资助项目2004BA803802-06~~
