初始温度条件下全尾胶结膏体损伤本构模型

Damage constitutive model of cemented tailing paste under initial temperature effect

膏体充填料到达采场初始温度不同是矿山存在的普遍现象,不同初始温度条件下膏体力学特性及应力-应变关系直接影响到矿山采充周期及相邻采场开采时贫化指标.通过对初始温度为2、20、35和50℃的硬化膏体进行单轴抗压强度试验,获得不同初始温度下充填体应力-应变演化曲线.根据理论推导和试验结果,建立了不同初始温度下膏体损伤本构模型,通过本构模型参数回归,提出膏体温度-时间耦合损伤本构模型.最后,采用Comsol数值模拟软件,将温度-时间耦合损伤本构模型嵌入solid mechanics模块,对单轴抗压试验进行数值模拟,模拟应力-应变曲线与试验结果较为吻合,验证了所提出本构模型的可靠性.

It is a universal phenomenon for all the mines that paste-filling material arrives at stope at different initial temperatures. The strength properties and stress-strain relation of paste at different initial temperatures have effect on the mining-filling cycle and the dilution of adjacent stope mining. A series of uniaxial compressive strength tests were performed on hardened paste with initial temperatures of 2,20,35 and 50 ℃ to obtain the stress-strain evolution curves at different initial temperatures. The damage constitutive models of paste at different initial temperatures were established on the basis of theoretical derivation and experimental results. A temperature- time coupling damage constitutive model was further proposed according to parameter regression of the established models. Finally,the temperature-time coupling damage constitutive model was embed into the solid mechanics module of Comsol software,which is for uniaxial compressive experiment simulation. The simulation results show good accordance with the experimental stressstrain curves,verifying the reliability of the proposed constitutive model.