摘要
采用正交试验方法设计了离散元模型细观参数正交试验序列,利用试验模拟计算结果和多因素非线性联合反演方法,建立了由宏观力学参数直接确定细观参数的计算方法,将该方法应用于煤系土三轴试验离散元数值模拟计算。结果表明:煤系土抗剪强度随摩擦系数的增大呈线性正相关,内摩擦角随摩擦系数增大呈现指数型关系增大,黏结力随着刚度比的增大而降低,呈幂函数变化关系;摩擦系数、法向黏结强度对煤系土抗剪强度影响非常显著,而切向黏结强度、刚度比和弹性模量对煤系土抗剪强度基本没有影响。数值模拟结果与室内三轴试验的应力—应变曲线吻合较好,经过误差分析发现,偏应力峰值的最大误差为5.4%,黏聚力的误差为2%,内摩擦角的误差为7%,误差都在10%以内,表明文中提出的细观参数快速确定方法是可行的,可为离散元数值模拟方法细观参数标定提供新思路。
The orthogonal test sequence of the meso parameters of the discrete element model was designed by using the orthogonal test method.The calculation method of directly determining the meso parameters from the macro mechanical parameters was established by using the test simulation calculation results and the multi-factor nonlinear joint inversion method.The proposed method was applied to the discrete element numerical simulation of triaxial test of coal measure soil.The results show that the shear strength of coal measures soil is linearly and positively correlated with the increase of friction coefficient,the internal friction angle increases exponentially with the increase of friction coefficient,and the cohesive force decreases with the increase of stiffness ratio,which is a power function.Friction coefficient and normal bonding strength have a significant effect on the shear strength of coal measures soil,while tangential bonding strength,stiffness ratio and elastic modulus have little effect on the shear strength of coal measures soil.The numerical simulation results are in good agreement with the stress-strain curves of the triaxial test of coal bearing soil.Through error analysis,it is found that the maximum error of the partial stress peak is 5.4%,the error of the cohesion is 2%,the error of the internal friction angle is 7%,and the error is all within 10%.It verifies that the method for rapid determination of the meso parameters proposed in this paper is feasible,and provides a new idea for the calibration of the meso parameters in the discrete element numerical simulation method.
作者
陈坤
廖良健
朱瑞
周子敬
张鸿
CHEN Kun;LIAO Liangjian;ZHU Rui;ZHOU Zijing;ZHANG Hong(School of Civil and Architectural Engineering,Nanchang Institute of Technology,Nanchang 330099,China)
出处
《南昌工程学院学报》
CAS
2023年第1期39-44,共6页
Journal of Nanchang Institute of Technology
基金
国家自然科学基金资助项目(52068053)
南昌市优势科技创新团队项目(2017CXTD012)。
关键词
煤系土
离散元模拟
细观参数标定
正交试验
多因素非线性回归
coal measure soil
discrete element simulation
calibration of meso parameters
orthogonal test
multivariate nonlinear regression
