煤岩单轴加载统计损伤本构模型

    Uniaxial Loading Statistical Damage Constitutive Model for Coal and Rock

    • 摘要: 为了研究煤岩单轴加载过程中的损伤演化规律,对煤岩进行了单轴加载实验,得到了煤岩的应力应变曲线、环向-轴向应变曲线。实验结果表明,煤岩加载过程中环向应变速率随着轴向应变的增加呈现出非线性增加的规律,并在煤岩加载进入软化阶段后达到最大值,它在宏观上反映了煤岩内部裂纹的产生与发展,并与煤岩的损伤演化规律相符。故定义损伤变量为裂纹体积的函数,并假设裂纹体积的增加符合威布尔统计规律,构建了煤岩统计损伤本构模型,通过与实验结果对比,验证了该模型的正确性。

       

      Abstract: In order to study the laws of damage evolution of coal and rock under uniaxial loading, the uniaxial loading test of coal and rock was done, and we obtained the stress strain curve and hoop to axial strain curve of coal and rock. The experimental results show that the hoop strain rate increases with the increase of axial strain, which presents nonlinear law in the loading process of coal and rock, and the increase rate reaches the maximum value when the coal is loaded into softening stage, which reflects the generation and development of internal crack of coal and rock at macro level, and conforms with the damage evolution law of the coal. So defining the damage variable as a function of crack volume, assuming the increase volume of crack conforms to Weibull statistical law, constructing a statistical damage constitutive model of coal, comparing with the experimental results, it verifies the correctness of the model.

       

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