岩石I类和II类曲线形成机制的弹塑性细胞自动机分析

基于弹脆塑性理论和细胞自动机自组织理论相结合来模拟岩石试样的应变软化行为,对岩样单轴压缩破坏过程中产生I类和II类曲线的机制进行模拟分析,利用应力-应变线性组合的控制加载方式,分别考虑不同的均质度和不同的加载控制参数的情况,并模拟非均质岩石单轴压缩破坏过程的I类和II类曲线。研究结果表明,当采用应力-应变线性组合的控制加载方式时,I类和II类曲线的出现与岩石试样的均质度和加载控制参数有很大的关系,均质度越大,岩石脆性越强,峰后越趋向于形成II类曲线;同一种岩石试样,采用不同的线性组合参数,岩样既可以表现为I类行为,也可表现为II类行为。

ANALYSIS OF MECHANISM OF ROCK BEHAVIORS OF CLASSES I AND II USING ELASTOPLASTIC CELLULAR AUTOMATA

Elasto-brittle-plasticity theory and cellular automata are introduced to model the strain softening behavior of rocks,and the theoretical analysis on Classes I and II behaviors of rocks failure process under uniaxial compression is performed using elasto-plastic cellular automata.The linear combination of stress and strain is used as the feedback signal to control the loading process.Simulations on uniaxial compression failure process of inhomogeneous rocks are conducted by this method,considering different homogeneity indices and different loading parameters.The results indicate that the rocks behave Class I or II greatly depends on the homogeneity of rocks and loading control parameters.The higher the homogeneous indices of rocks are,the more easily the rocks behave Class I curve I.Rock specimens with the same mechanical properties are characterized as Class I or II,which are controlled by loading control parameters.