基于颗粒真实几何形状的含瓦斯水合物煤体三轴试验离散元模拟  

Simulation of triaxial discrete element of MHBC based on real geometry of particles

作　　者：高霞 要远 Gao Xia;Yao Yuan(School of Architecture&Civil Engineering,Heilongjiang University of Science&Technology,Harbin 150022,China)

机构地区：[1]黑龙江科技大学建筑工程学院,哈尔滨150022

出　　处：《黑龙江科技大学学报》2024年第4期583-590,共8页Journal of Heilongjiang University of Science And Technology

基　　金：国家自然科学基金联合基金项目(U21A20111);国家自然科学基金面上项目(51974112)。

摘　　要：为了更加真实地模拟含瓦斯水合物煤体的力学特性,采用电镜扫描及二维离散元程序,提出了一种基于球度和扁平度的随机几何模型生成技术,建立基于室内三轴试验结果的二维离散元模型。通过构建不同瓦斯水合物饱和度的数值试样,模拟三轴压缩下含瓦斯水合物煤体的力学特性及变形破坏规律,从细观角度探究饱和度对其力学性质的影响机理。结果表明:随着饱和度增大,试样峰值强度和弹性模量呈线性增加,剪缩量略微减小,剪胀量明显增大;所有试样均呈先剪缩后剪胀,饱和度越大,进入剪胀阶段越快;当饱和度从20%提升至60%,试样内部的强力链数量明显增多,颗粒间的最大接触力提升了约50%,说明水合物越多,颗粒间粘结作用越强,从而提升了试样的峰值强度。This paper intends to simulate the mechanical characteristics behind methane hydrate-bearing coal(MHBC)more realistically and proposes a random geometric model generation technique based on sphericity and flatness with electron microscopy scanning and DEM,and establishes the two-dimensional DEM model according to the indoor triaxial test results.The study is accomplished by establishing the numerical samples with different gas hydrate saturation;simulating the mechanical properties and deformation failure laws behind MHBC under triaxial compression;and exploring the influence mechanism of saturation on the mechanical properties of MHBC from the meso-perspectives.The results show that with the increase of the saturation,the peak strength and elastic modulus of the sample increase linearly,the shear shrinkage decreases slightly,and the shear expansion increases significantly.All samples show the deformation characteristics of first shear contraction and then dilatancy;and the greater the saturation,the faster the sample enters the shear dilatancy stage.When the saturation increases from 20%to 60%,the number of strong chains inside the sample increases significantly,and the maximum contact force between particles increases by about 50%,indicating that the more the saturation of hydrate,the stronger the inter-particle bonding,which further increases the peak strength of the MHBC.

关 键 词：含瓦斯水合物煤 不规则颗粒 宏细观力学特性 

分 类 号：TD712[矿业工程—矿井通风与安全]