煤岩非线性损伤蠕变模型探析

Study on the nonlinear damage creep model of coal and rock

为了研究煤岩蠕变特性,分析前人煤岩蠕变特性实验结果,在广义Kelvin模型的基础上建立了煤岩非线性损伤蠕变理论模型。假定煤岩损伤演化是应力和时间的函数,同时引入非线性硬化函数推导了煤岩非线性损伤衰减蠕变方程和蠕变全过程方程。任意给定方程中材料参数和加载条件,理论得到了煤岩衰减蠕变和蠕变全过程随时间变化曲线,对比前人煤岩蠕变实验结果,验证了用理论模型去研究煤岩的蠕变特性是可行的。

In order to study the coal creep properties,this study analyzed the previous experimental results of coal creep properties and developed a nonlinear damage creep model for coal damage based on a general Kelvin model.Assuming the coal damage is a function of stress level and time,and introducing a nonlinear hardened function,a nonlinear damage fading creep equation and a nonlinear damage creep whole process equation were derived.When the values of the material parameters in the two equations are provided,the theoretical creep curves varying with time will be obtained under different uniaxial compressions.Comparing the theoretical curves obtained with the previous experimental results of coal creep,the nonlinear damage creep model developed in this study is proved to be feasible in modeling the coal creep properties.