一种基于熵增理论的疲劳-蠕变交互作用损伤模型及试验验证

发布时间：2018-05-14 04:42

  本文选题：疲劳-蠕变 + 熵增　； 参考：《中国机械工程》2016年10期

【摘要】：根据经典热力学理论,材料疲劳-蠕变交互作用下的损伤过程可视为系统熵增的累积,当熵增积累到临界值时,材料发生失效断裂。按此理论,并基于连续损伤力学和能量守恒定律,以系统熵增的变化来描述材料损伤,建立了一种疲劳-蠕变交互作用的损伤模型。为验证该模型,进行了540℃和520℃环境下1.25Cr-0.5Mo钢应力控制的梯形波加载试验,以材料的残余应变反映熵增积累,选取残余应变的变化作为损伤变量,用上述损伤模型进行了材料疲劳-蠕变交互作用的损伤演化描述,结果表明实测损伤点数据与该模型的损伤演化规律符合较好。
[Abstract]:According to the classical thermodynamic theory, the damage process under the interaction of fatigue and creep can be regarded as the accumulation of entropy in the system. When the entropy accumulation reaches the critical value, the failure fracture of the material occurs. According to this theory, and based on the law of continuous damage mechanics and energy conservation, the damage of materials is described by the change of entropy increase of system, and a damage model of fatigue creep interaction is established. In order to verify the model, the stress controlled trapezoidal wave loading tests of 1.25Cr-0.5Mo steel at 540 鈩，

本文编号：1886401