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1 – 4 of 4Istvan Oldal, Ferenc Safranyik and Istvan Keppler
The purpose of this study is the reduction of computational time demand of discrete element based modeling.
Abstract
Purpose
The purpose of this study is the reduction of computational time demand of discrete element based modeling.
Design/methodology/approach
The methodology is the systematic changing of particle size and micromechanical parameters to reduce computational time requirements.
Findings
In some cases, the computational demand of discrete simulations can be reduced to about 95 per cent.
Originality/value
Based on the results and demonstrated methodology, the enormous computational time demand of discrete element-based modeling can be reduced significantly.
Details
Keywords
Istvan Keppler, Ferenc Safranyik and Istvan Oldal
The effect of micromechanical parameters on the macromechanical behaviour of granular materials is analysed by using discrete element based model of the standard shear test.
Abstract
Purpose
The effect of micromechanical parameters on the macromechanical behaviour of granular materials is analysed by using discrete element based model of the standard shear test.
Design/methodology/approach
Discrete element method based standard shear test simulations.
Findings
The approximate mathematical functions related to the effects of DEM micromechanical parameters density, Young-modulus, Poisson number, frictional angle, bond normal cohesion, bond tangential cohesion, rolling friction and particle shape on the macromechanical parameters of shear failure line (internal friction and cohesion) are determined by modelling large number of standard shear tests.
Originality/value
By knowing these effects of micromechanical parameters to the macromechanical behaviour of the simulated particle assembly, the calibration of discrete element models can be significantly accelerated.
Istvan Keppler, Zoltan Hudoba, Istvan Oldal, Attila Csatar and Laszlo Fenyvesi
– The analysis of the effect of tool vibrations on the measured and simulated draught forces of cultivator tools. This paper aims to discuss this issue.
Abstract
Purpose
The analysis of the effect of tool vibrations on the measured and simulated draught forces of cultivator tools. This paper aims to discuss this issue.
Design/methodology/approach
Soil bin measurements and discrete element method (DEM)-based simulations.
Findings
The soil-tool interaction induced free vibrations of cultivator tools have significant impact on the measured draught force, and the simulations made by using vibrating tools give similar results.
Research limitations/implications
Accurate calibration of discrete element model parameters can be done based on the reproduction of the whole Mohr-Coulomb failure line. Draught force ratio – velocity ratio values seem to be independent of tool geometry and soil conditions in case of velocity ratio higher than 2.
Practical implications
DEM-based numerical simulations can be used for modeling the effect of tool vibration on the draught force values. During discrete element simulations of soil-tool interaction, the effect of tool vibration may not be neglected.
Originality/value
The paper demonstrates that during the discrete element modelling of the soil-tool interaction, the tool vibration phenomenon should not be neglected.
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Keywords
Istvan Keppler, Adrienn Bablena, Nihal D. Salman and Péter Kiss
Transportation of the measurement samples from their original place to the measurement site causes significant changes in their mechanical properties. The possibility of making in…
Abstract
Purpose
Transportation of the measurement samples from their original place to the measurement site causes significant changes in their mechanical properties. The possibility of making in situ measurements helps to create more precise discrete element models.
Design/methodology/approach
The possibility of using in situ modified vane shear test based measurement for the calibration of discrete element models is demonstrated in this work.
Findings
The advantage of employing the adjusted vane test is that the values of in situ measurements can be used for the calibration.
Originality/value
The procedure we present allows us to perform accurate discrete element calibration using data from on-site measurements that can be performed quickly and easily.
Details