scholarly journals Calibration of Discrete-Element-Method Parameters for Cohesive Materials Using Dynamic-Yield-Strength and Shear-Cell Experiments

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 278 ◽  
Author(s):  
Subhodh Karkala ◽  
Nathan Davis ◽  
Carl Wassgren ◽  
Yanxiang Shi ◽  
Xue Liu ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Surface Energy ◽  
Yield Strength ◽  
Discrete Element Method ◽  
Critical State ◽  
Discrete Element ◽  
Shear Cell ◽  
Dynamic Yield Strength ◽  
Dynamic Yield ◽  
Friction Parameters

This study tested the effectiveness of using dynamic yield strength (DYS) and shear-cell experiments to calibrate the following discrete-element-method (DEM) parameters: surface energy, and the coefficients of sliding and rolling friction. These experiments were carried out on cohesive granules, and DEM models were developed for these experiment setups using the JKR cohesion contact model. Parameter-sensitivity analysis on the DYS model showed that the DYS results in the simulations were highly sensitive to surface energy and were also impacted by the values of the two friction coefficients. These results indicated that the DYS model could be used to calibrate the surface energy parameter once the friction coefficients were fixed. Shear-cell sensitivity analysis study found that the influence of surface energy on the critical-state shear value cannot be neglected. It was inferred that the shear-cell model has to be used together with the DYS model to identify the right set of friction parameters. Next, surface energy was calibrated using DYS simulations for a chosen set of friction parameters. Calibrations were successfully conducted for simulations involving experimentally sized particles, scaled-up particles, a different shear modulus, and a different set of friction parameters. In all these cases, the simulation DYS results were found to be linearly correlated with surface energy and were within 5% of the experimental DYS result. Shear-cell simulations were then used to compare calibrated surface-energy values for the scaled-up particles with the experimentally sized particles. Both the simulations resulted in similar critical-state shear values. Finally, it was demonstrated that a combination of DYS and shear-cell simulations could be used to compare two sets of friction parameters and their corresponding calibrated surface energy values to identify the set of parameters that better represent the flow behavior demonstrated by the experimental system.

Measurement of Dynamic Stress and Strain in Tensile Test Specimens

1944 ◽  
Vol 11 (2) ◽  
pp. A65-A71
Author(s):  
R. O. Fehr ◽  
E. R. Parker ◽  
D. J. DeMicheal
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Testing Machine ◽  
Impact Testing ◽  
High Rate ◽  
Stress And Strain ◽  
Dynamic Tensile Strength ◽  
Dynamic Yield Strength ◽  
Dynamic Yield ◽  
Cold Rolled

Abstract In the investigation detailed in this paper, the tensile strength, the yield strength, and the breakage energy of test specimens (cold-rolled steel and dural) were measured while the specimens were being broken by a force applied at a high rate of speed in a commercial high-velocity impact-testing machine. The dynamic tensile strength, the dynamic yield strength and the dynamic breakage energy were found to be higher than the static values up to the maximum impact velocities of these tests (100 fps). The paper contains: (1) A presentation of some results of these tests. (2) A description of the technique used. (3) A description of the analysis used.

The Prospect and Review of DEM Model Using in Saturated and Unsaturated Soil

2011 ◽  
Vol 105-107 ◽  
pp. 1371-1375
Author(s):  
De Cheng Feng ◽  
Wen Xin Zuo ◽  
Peng Cao
Keyword(s):  
Surface Energy ◽  
Discrete Element Method ◽  
Unsaturated Soil ◽  
Soil Mechanics ◽  
Discrete Element ◽  
Saturated Soil ◽  
Powerful Technique ◽  
Paper Review ◽  
Real Practice ◽  
Dem Model

The saturated and unsaturated soil were widely studied by many researchers nowadays. With the development of calculation mechanics and computer, the discrete element method (DEM), as a powerful technique, has been implemented in saturated soil mechanics. This paper review the development of DEM and its application in saturated soil research. Meanwhile, it also prospect the application of DEM in unsaturated soil research. Besides, it also raised some problems that might be met in the real practice and it also tried to put forward some reasonable methods to solve these problems. In the end, this paper put forward a new DEM contact model based on the surface energy to analysis unsaturated soil.

The Dynamic Yield Strength of Steel at an Intermediate Rate of Loading

1948 ◽  
Vol 159 (1) ◽  
pp. 11-23 ◽  
Author(s):  
A. F. C. Brown ◽  
R. Edmonds
Keyword(s):  
Yield Strength ◽  
Alloy Steel ◽  
Underwater Explosion ◽  
Low Alloy Steel ◽  
Heat Treated ◽  
Static Tensile ◽  
Static Yield ◽  
Dynamic Yield Strength ◽  
Dynamic Yield ◽  
Rate Of Loading

A comparison has been made between the dynamic and static tensile yield strengths of eight steels varying from mild steel to a heat-treated low-alloy steel, the rate of loading in the dynamic tests being such as would occur in a ship under the action of an underwater explosion. The dynamic yield strength of the steels with low static strength was 20–30 per cent greater than their static yield strength but, for the stronger steels, the increase was less, being negligible in the case of the heat-treated low-alloy steel. This result conforms with the findings of other investigators, and shows that any increase in strength under the dynamic loading considered is too small to be of importance in design.

scholarly journals Temperature dependence of dynamic yield strength and spall strength for LY12 aluminum alloy under shock loading

2006 ◽  
Vol 55 (8) ◽  
pp. 4202
Author(s):  
Wang Yong-Gang ◽  
Chen Deng-Ping ◽  
He Hong-Liang ◽  
Wang Li-Li ◽  
Jing Fu-Qian
Keyword(s):  
Aluminum Alloy ◽  
Yield Strength ◽  
Temperature Dependence ◽  
Shock Loading ◽  
Spall Strength ◽  
Dynamic Yield Strength ◽  
Dynamic Yield
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