海底多金属硫化物材料本构模型研究

Study of Material Constitutive Model of Seafloor Massive Sulfide

为得到适用于数值模拟的海底多金属硫化物材料本构模型,针对海底多金属硫化物试样进行了不同围压下的单/三轴压缩实验,得到物理力学特性参数,对比分析常用描述岩石物理力学行为的本构模型及岩石微元强度准则,选择了合适的材料本构模型并确定了相应参数,并通过单个单元的仿真验证了模型的正确性,且仿真结果表明当海水围压超过20~25MPa区间内的某特定值时,多金属硫化物将会产生明显的脆-延转化。进一步基于该模型开展了高围压条件下双截齿切削海底多金属硫化物数值模拟的动力学特性研究,仿真结果表明随着围压增大,截齿受到的截割阻力及进给阻力显著增大,载荷波动性降低。

In order to get the appropriate material constitutive model for numerical simulation of cutting seafloor massive sulfide,uniaxial/triaxial compression experiments were carried out for the seabed polymetallic sulphide samples.And the physical and mechanical characteristic datas of seafloor massive sulfide were obtained.By comparing the commonly used constitutive models and the micro strength criterions in describing the physical and mechanical behavior of rocks,appropriate constitutive model which had a good correspondence with the polymetallic sulphide crushing environment was selected and the detailed parameters were determined based on the experimental datas.Moreover,the correctness of the model was validated through the simulation of a single element,and the simulation results indicate that the seafloor massive sulfide will transform from brittle to ductile obviously when the confining pressure is more than a specific value in the range of 20 MPa^25 MPa.Based on the model confirmed above,the numerical simulation of double picks cutting seafloor massive sulfide ore under different confining pressures was carried out,and the dynamics characteristic curves of the pick were obtained.The curves show that with the increase of confining pressure,the maximum values and the average values of the cutting resistance and the feeding resistance which are the main part of the resistances increase apparently and the volatility of the resistances is significantly reduced.