孔隙多金属硫化物细观力学和切削载荷特性的数值模拟

Numerical Simulation of Micromechanics and Load Characteristics of Porous Seafloor Massive Sulfide During Cutting Process

为了提高生成矿体网格单元的质量以及求解效率,利用有限元软件结合APDL语言提出了一种针对孔隙多金属硫化物复杂几何模型的网格优化措施,实现了整体映射网格与局部自由网格相结合的划分方法;对多金属硫化物受压损伤破坏过程和围压下单截齿切削破碎孔隙矿体过程进行了数值模拟,分析了孔隙率及孔隙形态对多金属硫化物细观力学行为和切削载荷特性的影响。研究结果表明,在外载作用下,海底多金属硫化物矿体孔隙结构密集区域易出现应力集中现象,同时随着狭长裂隙出现,应力集中现象更加明显,从而使矿体更容易失稳破坏;在单截齿切削破碎矿体过程中,随着孔隙率增加,矿体破碎过程所需切削载荷有所减小,并且在矿体由等轴孔隙向狭长孔隙过渡过程中,应力集中加剧并且切削载荷进一步减小。

In order to improve the quality of the generated grid unit and the solution efficiency for ore deposit,a grid optimization method for the complex geometric model of seafloor massive sulfide(SMS)was proposed based on finite element software combined with APDL language,so as to realize the combination of an overall reflection grid and local free grid in the grid generation method.The failure process of SMS caused by compression damage and the crushing process with single-tooth cutter under the confining pressure were numerically simulated.The effects of porosity and pore morphology on the micro-mechanical behavior and loading characteristics of SMS during the cutting process were analyzed.The results show that under an external loading action,a stress concentration is prone to occur in the part of SMS with dense pore structures.At the same time,the appearance of long and narrow cracks will make the stress more concentrated,leading to the ore deposit more instable and prone to failure.During the ore deposit is crushed with a single-tooth cutter,an increased porosity will lead to the decrease in the cutting load required for crushing ore deposit.And during the transition from ore deposit with equiaxed pores to narrow pores,the stress concentration will be intensified and the cutting load is further reduced.