【作者】 谭松成； 段隆臣； 高辉；

【Author】 Tan Song-Cheng 1 Duan Long-Chen 2 Gao Hui 1 Engineering Research Center of Rock-Soil Drilling & Excavation and Protection, Ministry of Education, Wuhan 430074, China 2 Faculty of Engineering, China University of Geosciences, Wuhan 430074, China

【机构】 岩土钻掘与防护教育部工程研究中心； 中国地质大学工程学院；

【摘要】 利用离散元法中的二维颗粒流方法(PFC2D),应用线性接触刚度模型对模拟月壤颗粒进行细观数值模拟,探讨了不同围压条件下,重力测试环境对模拟月壤试样宏观变形和强度特征参数的影响规律和程度。研究结果表明,在不同围压和重力测试环境下,重力因素对试样最大体变压缩变形值的影响最为显著,其最大试验偏差为18.85%;对试样轴向应力峰值强度的影响次之,最大试验偏差为2.56%;对试样最大体变剪胀变形值的影响最小,其偏差值均小于2%,可忽略不计。重力测试环境对无粘(或低粘)性松散模拟月壤试样的宏观力学特征影响显著,无重力环境下的内聚力测试结果显著高于重力环境,而内摩擦角则稍小于重力环境下的测试结果。更多还原

【Abstract】 The paper presents a discrete element method named particle flow code in two-dimension (PFC2D). Linear contact stiffness model was employed to simulate the behavior of lunar soil under conventional triaxial compression condition. Effect and degree of gravity environment on macroscopical deformation and strength characteristics of simulated lunar soil samples were discussed under different confining pressure conditions. The study results showed that under different confining pressure conditions and gravity test environments, effect of gravity on the biggest compression value of volumetric strain was the most significant with a maximum error of 18.85%. Effect on axial peak stress was the next significant with a maximum error of 2.56%. The effect of gravity on the biggest dilatancy value of volumetric strain was the least significant with all testing errors lower than 2%, so it can be omitted. Gravity testing environment was significant to macromechanics characteristics of cohesionless material. Cohesion test result under no gravity environment was bigger than gravity conditions remarkably, while internal friction angle was smaller than the test results under gravity conditions slightly.更多还原