摘要
以EDEM软件的Hertz-Mindlin with bonding (HMB)接触模型为基础,对岩石离散元模型构建方法进行了研究。首先,确保HMB岩石模型的黏结键全部为弱键,即黏结键抗拉强度小于其法向极限应力,然后通过仿真试验,分别建立了岩石模型的弹性模量E、泊松比μ和抗拉强度σt与颗粒和黏结键参数之间的3个回归关系式。根据上述3个回归关系式,构建了用HMB模型拟合真实岩石E、μ、σt的数学模型。对HMB岩石模型的抗压强度σc,当黏结键的极限应力比(法向极限应力σmax/切向极限应力τmax)δτσ在1~2范围内时,σc受到σmax、τmax以及二者比值δστ的共同影响,特别是δστ在1.5附近时,单轴压缩仿真试验的破坏形式与试验结果吻合的较好,且δστ一定时,σc与σmax呈线性关系。综合上述成果,提出了一种拟合真实岩石试样的弹性模量E、泊松比μ、抗拉强度σt、抗压强度σc以及岩石试样破坏形式的HMB岩石模型构建方法,并给出了详细拟合步骤。最后通过实例验证了按照此方法构建的砂岩和花岗岩模型既能够拟合岩石的静态力学特性,也可用于分析岩石的动态力学特性。
Based on the Hertz-Mindlin with bonding(HMB) contact model in EDEM,the modeling method of the rock discrete element model was investigated.First of all,all of the bonds in HMB rock model must be "weak bond",i.e.,the tensile strength of the bond is less than its critical normal stress.Then,the regression relationships between the elastic modulus E,Poisson’s ratio μ,tensile strength σt of rock model and the particle and bond parameters were established,respectively.According to the three regression relationships,a mathematical model that can fit the real-rock’s E,μ,and σt through the HMB model was proposed.For the compressive strength σc of rock,when the critical stress ratio δστ(δστ=σmax/τmax,σmax is critical normal stress,and τmax is critical tangential stress) ranges from 1 to 2,σc is influenced by σmax,τmax and the ratio δστ of critical normal to tangential stress.Especially,when the δστ is closed to 1.5,the failure mode of the rock model presents a better agreement with the experiment result.In addition,when the δστ is constant,a linear relationship between the σc and σmax can be clearly observed.In conclusion,a HMB model based modeling method that can fit the elastic modulus,Poisson’s ratio,tensile strength,compressive strength and the failure form of rock sample was proposed,and the detail steps were also given.Finally,an example was conducted to verify the proposed modeling method.The results showed that the rock models established through the proposed method can fit both the static and dynamic mechanical properties of rock.
作者
申浩翰
张海
范俊锴
徐瑞阳
张小明
SHEN Hao-han;ZHANG Hai;FAN Jun-kai;XU Rui-yang;ZHANG Xiao-ming(School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo,Henan 454002,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2021年第8期2298-2310,2320,共14页
Rock and Soil Mechanics
基金
国家自然科学基金(No.51975189)。
关键词
岩石
多参数
拟合
建模方法
rock
multi-parameters
fitting
modeling
