【摘要】 为了对疲劳与循环蠕变交互作用下的损伤进行定量描述,采用一种新的损伤参量“等效模量”来定义损伤变量,提出了一种损伤力学模型,该模型能够综合体现最大应力和温度的影响.通过16MnR钢在中温应力控制条件下的脉动循环试验,测出在相同温度、不同最大应力以及相同最大应力、不同温度下的损伤变量变化规律.在适当假设的基础上,得到16MnR钢在不同最大应力、不同温度下的疲劳与循环蠕变交互作用的损伤表达式.结果表明,该损伤参量及损伤模型适用于描述在疲劳与循环蠕变交互作用下的损伤进程.更多还原

【Abstract】 In order to quantitatively describe the damage of interaction between fatigue and cyclic creep,a new damage parameter named equivalent modulus was proposed to define the damage variable,and a continuum damage mechanics(CDM) model considering both effects of maximum stress and temperature on damage evolution was put forward.By a series of pulsating cyclic tests of 16MnR steel under stress control at elevated temperature,transformation laws of the damage variable were measured at different maximum stresses at the same temperature and different temperature at the same maximum stress.Based on several hypotheses,the laws of damage evolution of 16MnR steel under various loading conditions with different maximum stress and temperature were derived.Results indicate that the damage parameter and the damage model are applicable for describing the damage evolution of fatigue and cyclic creep interaction.更多还原