中文摘要：

将镁碳质耐火材料视为骨料和细粉基质组成的两相复合材料,采用基于离散元的颗粒流模拟软件PFC^2D,将材料离散成刚性颗粒组成的模型,把颗粒细观参数的变化与宏观力学特性联系起来,构建镁碳质耐火材料在1000℃下的试验模型,模拟试样三点弯曲的载荷-位移曲线,对材料裂纹的扩展进行分析,并通过改变摩擦系数、平行粘结刚度比、孔隙率以及平行粘结弹性模量,对比分析细观参数对载荷力峰值大小的影响情况。结果表明,采用PFC^2D可准确模拟镁碳质耐火材料在三点弯曲时的断裂行为;材料的摩擦系数和平行粘结弹性模量与试样所受最大载荷力呈正比关系,而孔隙率和平行粘结刚度比与试样所受最大载荷力呈反比关系。

英文摘要：

MgO-C refractory material is regarded as a two-phase composite material consisting of aggregate and fine powder.In this study,particle flow simulation software PFC^2 D,which is based on discrete elements,was employed to discretize the material into a rigid particle model,and the microscopic variation of the particles was related to the macroscopic mechanical properties of the material.Under 1000℃,the experimental model of the MgO-C material was established,and three-point bending load-displacement curves of the samples were simulated.Material crack propagation was analyzed,and by changing the friction coefficient,parallel bond stiffness ratio,porosity and elastic modulus of the whole model,the influence of microscopic parameters on the value of the peak load was compared.The results show that PFC2 Dcan accurately simulate the three-point bending fracture behavior of the magnesium carbon refractory material.The friction coefficient and parallel bond elasticity modulus of the material are proportional to the peak load force of the samples,and the porosity and the parallel bond stiffness ratio of the material are inversely proportional to the peak load force of the samples.