A numerical assessment of strain rate effects on the critical state of crushable granular materials

The present study highlights the effects of strain rate on the critical state response of crushable granular materials. A set of drained triaxial tests is simulated using the discrete element method (DEM) to understand the rate effects on the stress-strain and volumetric behaviour of the granular sample. The DEM parameters are obtained by comparing the stress-strain and particle crushing behaviour of in-house experimental analysis on crushable coral sand under a slow strain rate. In DEM, the particles are subjected to varied strain rates under different initial confining pressures and initial densities to capture the rate effects on the macroscopic responses until the critical state. It is seen that crushing increases with increasing confining stress. However, a higher strain rate induces relatively lower crushing and higher strength in terms of both peak stress and residual stress. It is observed that in pressure-volume space, the critical state line alters with the increasing strain rate of the crushable samples, especially at high confining conditions, whereas strain rate effect on critical state seems to be negligible at low confining conditions due to the absence of particle crushing.

Evaluation Of Stress-Strain State Of Vehicles’ Metal Structures Elements

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Experience of CAE Fidesys application in numerical geomechanical modelling of Zhdanovskoe deposit

The Zhdanovskoe copper-nickel sulfide ores deposit is located in the north-west of the Murmansk region and is a mineral raw material source for JSC «Kola MMC». The main mining method used is sublevel caving. In some areas, due to the complex shape of the ore bodies, the open stoping mining method is used which requires determining stable parameters of stopes and pillars. It is necessary to study the stress-strain state of the deposit to ensure safe mining conditions. One of the possible solutions is the modeling of the stress-strain state of rock mass using the finite element method, for example, CAE Fidesys, which is FEMbased software. The use of CAE Fidesys for solving geomechanics tasks allows creating models of individual excavation units to determine the stability of stopes and pillars, and large-scale models that include several ore bodies and areas of the host rock mass. The article considers solutions of both types of geomechanic tasks using CAE Fidesys for conditions of the Zhdanovskoe deposit.