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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 explore the regularity of mechanical properties of coal under different temperatures, a theoretical analysis and numerical experiments were carried out. By combining thermal knowledge with the knowledge of fracture mechanics, a numerical experiment was conducted by using RFPA2D-temperature plate to study the influence of temperature on the mechanical behavior of coal and rock. The results show that the existence of variable temperature stress makes the cracks in coal and rock more likely to occur and develop, the temperature increases the fracture strength factor and changes the stress field at crack tip, and the bearing capacity of coal and rock decreases with the increase of temperature. Numerical experiment further verifies that the bearing capacity of rock decreases gradually with increasing temperature.With the increase of mean value, the discreteness of the mechanical properties of coal particles decreases, the linear increment of single-step load increases obviously and the carrying capacity increases gradually .