热-固耦合煤岩力学性质

Experiment of the mechanical property of coal thermal-structure interaction

为探究不同温度下煤体力学性质变化规律,采用理论分析与数值试验相结合的方法,从热效应角度结合断裂力学相关知识,利用RFPA2D-温度版对温度影响的煤岩力学行为变化规律进行数值试验,研究结果表明:变温度应力的存在使得煤岩内部裂隙更易产生和发育,温度增加了裂纹的断裂强度因子,改变了裂纹尖端应力场.随温度升高煤岩承载能力不断降低,试验结果从数值实验角度进一步验证随温度升高岩石承载能力逐渐降低的变化规律.随着均值度升高,煤岩内部颗粒单元力学性质离散性降低,线性阶段载荷单步增量明显提高,承载能力逐渐增加.

In order to study the variation of coal mechanical properties under different temperature, this paper conducted the numerical test of the mechanical property of coal influence by using RFPA2D- thermal and with the method of theoretical analysis and numerical test combination. From the viewpoint of thermal effect, the fracture mechanics knowledge is applied in this study. The result shows that the temperature-change stress make cracks of coal easier to produce and develop, the fracture strength factor of internal cracks in coal was enhanced and the crack tip stress field was changed by thermal. The carrying capacity of coal decreased with the temperature growth, and the result further verified the rule of carrying capacity of rock decreased with the temperature growth future from the view of numerical test. With the growth of heterogeneity and the discreteness of mechanical property of the inner coal matrix particles unit, the stress increment of single facula improve significantly at linear stage, and the carrying capacity of coal increased gradually.