Calibration and uniqueness analysis of microparameters for DEM cohesive granular material  

作　　者：Songtao Ji Jurij Karlovšek 

机构地区：[1]School of Civil Engineering,The University of Queensland,Brisbane 4067,Australia

出　　处：《International Journal of Mining Science and Technology》2022年第1期121-136,共16页矿业科学技术学报（英文版）

摘　　要：The differential evolution(DE)algorithm was deployed to calibrate microparameters of the DEM cohesive granular material.4 macroparameters,namely,uniaxial compressive strength,direct tensile strength,Young’s modulus and Poisson’s ratio,can be calibrated to high accuracy.The best calibration accuracy could reach the sum of relative errors RE_(sum)<0.1%.Most calibrations can be achieved with RE_(sum)<5%within hours or RE_(sum)<1%within 2 days.Based on the calibrated results,microparameters uniqueness analysis was carried out to reveal the correlation between microparameters and the macroscopic mechanical behaviour of material:(1)microparameters effective modulus,tensile strength and normal-to-shear stiffness ratio control the elastic behaviour and stable crack growth,(2)microparameters cohesion and friction angles present a negative linear correlation that controls the axial strain and lateral strain prior to the peak stress,and(3)microparameters friction coefficient controls shear crack friction and slip mainly refers to the unstable crack behaviour.Consideration of more macroparameters to regulate the material mechanical behaviour that is dominated by shear crack and slip motion is highlighted for future study.The DE calibration method is expected to serve as an alternative method to calibrate the DEM cohesive granular material to its peak strength.

关 键 词：Discrete element method(DEM) Particle flow code(PFC) Differential evolution(DE) Parameter calibration Uniqueness analysis Post-peak behaviour 

分 类 号：TB34[一般工业技术—材料科学与工程]