摘要
在PM空间中,隐含内力效应的滞回细观单元在对外载响应过程中,由于部分单元是否响应存在着不确定性,导致循环加载时滞回圈的不稳定.外载频率和温度不同,岩石中微细观结构参与对宏观外力和温度响应的转换概率亦不同.通过单轴和三轴循环加载和数值模拟获得:频率越高,微细观结构对外力响应的转换概率越小,自适应调整时间越短,残余应变也就越小,滞回圈越容易趋于稳定;随着温度不断升高,微细观结构对温度响应的转换概率增大,自适应调整的时间就越长,滞回圈向应变增大方向散开趋于不稳定.所以,岩石中的细观裂纹、孔洞、晶粒边界也存在对外载响应的概率,降低频率与升高温度都将导致滞回圈趋于不稳定,显示降低外载频率(增长每一个循环载荷的作用时间)与升高温度具有某种等效性.
In PM （Preisach-Mayergoyz） space, during the response of HMU （hysteretic mesoscopic unit） with internal forces to external forces, the number of HMUs responding to external forces is uncertain, which leads to the instability of hysteretic loops. Transition probability of HMUs to the external force and temperature varies with external loading frequency and temperature. The self-adaptive adjustment effects for rocks in the frequency field were obtained by uniaxial and triaxial cyclic loading： when the frequency increases, the transition probability of the response of mesoscopic structure to applied loads reduces, the adjustment time of self-adaptive process becomes shorter, residual strain becomes smaller, and hysteretic loops tend to be stable easily. The self-adaptive adjustment effects in temperature field： when the temperature increases, the transition probability of the response of the mesoscopic structure to applied loads increases, the adjustment time of the selfadaptive process becomes longer, and hysteretic loops disperse with the increase of the strain and tend to be unstable. So, reducing frequency and raising temperature will both cause hysteretic loops tend to be unstable, which indicates that there is kind of a equivalence between the reducing frequency and the raising temperature.
基金
国家自然科学基金(40474065)资助
