Numerical Simulations of Topologically Interlocked Materials Coupling DEM Methods and FEM Calculations: Comparison with Indentation Experiments

2009 ◽  
Vol 1188 ◽  
Author(s):  
Charles Brugger ◽  
Marc C. Fivel ◽  
Yves Bréchet
Keyword(s):  
Surface Roughness ◽  
Finite Element ◽  
Numerical Modeling ◽  
Discrete Element Method ◽  
Numerical Simulations ◽  
Constitutive Equations ◽  
Discrete Element ◽  
Finite Element Simulations ◽  
Compression Stress ◽  
Numerical Tool

AbstractPlanar assemblies of interlocked cubic blocs have been tested in indentation. Experiments are performed on blocs made of plaster. Influence of key parameters such as the surface roughness, the compression stress and the number of blocs are investigated. A numerical modeling is then proposed based on discrete element method. Each bloc is represented by its centre coordinates. Constitutive equations obtained by finite element simulations are introduced to model the contact between the blocs. The numerical tool is then applied to the case of indentation loading. It is found that the model reproduces all the experimental tendencies.

scholarly journals Numerical Modeling of a Punch Penetration Test Using the Discrete Element Method

2020 ◽  
Vol 28 (2) ◽  
pp. 1-7
Author(s):  
Rouhollah Basirat ◽  
Jafar Khademi Hamidi
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Numerical Models ◽  
Confining Pressure ◽  
Discrete Element ◽  
Numerical Results ◽  
Strength Parameter ◽  
Penetration Test ◽  
Strength Parameters ◽  
Element Method

AbstractUnderstanding the brittleness of rock has a crucial importance in rock engineering applications such as the mechanical excavation of rock. In this study, numerical modeling of a punch penetration test is performed using the Discrete Element Method (DEM). The Peak Strength Index (PSI) as a function of the brittleness index was calculated using the axial load and a penetration graph obtained from numerical models. In the first step, the numerical model was verified by experimental results. The results obtained from the numerical modeling showed a good agreement with those obtained from the experimental tests. The propagation path was also simulated using Voronoi meshing. The fracture was created under the indenter in the first step, and then radial fractures were propagated. The effects of confining pressure and strength parameters on the PSI were subsequently investigated. The numerical results showed that the PSI increases with enhancing the confining pressure and the strength parameter of the rock, including cohesion and the friction angle. A new relationship between the strength parameters and PSI was also introduced based on two variable regressions of the numerical results.

scholarly journals Numerical Modeling of Viscoelasticity in Particle Suspensions Using the Discrete Element Method

Langmuir ◽  
2019 ◽  
Vol 35 (39) ◽  
pp. 12754-12764 ◽  
Author(s):  
Alexandr Zubov ◽  
José Francisco Wilson ◽  
Martin Kroupa ◽  
Miroslav Šoóš ◽  
Juraj Kosek
Keyword(s):  
Numerical Modeling ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Particle Suspensions ◽  
Element Method

scholarly journals Accounting for Tube Hematocrit in Modeling of Blood Flow in Cerebral Capillary Networks

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Nikolai D. Botkin ◽  
Andrey E. Kovtanyuk ◽  
Varvara L. Turova ◽  
Irina N. Sidorenko ◽  
Renée Lampe
Keyword(s):  
Finite Element ◽  
Blood Flow ◽  
Numerical Simulations ◽  
Hydraulic Resistance ◽  
Analytic Formula ◽  
Finite Element Simulations ◽  
Hematocrit Level ◽  
Capillary Networks ◽  
Cerebral Capillary ◽  
Flow Through

The aim of this paper consists in the derivation of an analytic formula for the hydraulic resistance of capillaries, taking into account the tube hematocrit level. The consistency of the derived formula is verified using Finite Element simulations. Such an effective formula allows for assigning resistances, depending on the hematocrit level, to the edges of networks modeling biological capillary systems, which extends our earlier models of blood flow through large capillary networks. Numerical simulations conducted for large capillary networks with random topologies demonstrate the importance of accounting for the hematocrit level for obtaining consistent results.

scholarly journals Micromechanical Numerical Modelling on Compressive Failure of Recycled Concrete using Discrete Element Method (DEM)

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4329
Author(s):  
Xin Tan ◽  
Zhengbo Hu ◽  
Wengui Li ◽  
Suhua Zhou ◽  
Tenglong Li
Keyword(s):  
Discrete Element Method ◽  
Numerical Simulations ◽  
Discrete Element ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Image Correlation ◽  
Recycled Aggregate ◽  
Nanoindentation Test ◽  
Aggregate Concrete ◽  
Element Method

This paper investigates the failure processes of recycled aggregate concrete by a model test and numerical simulations. A micromechanical numerical modeling approach to simulate the progressive cracking behavior of the modeled recycled aggregate concrete, considering its actual meso-structures, is established based on the discrete element method (DEM). The determination procedure of contact microparameters is analyzed, and a series of microscopic contact parameters for different components of modeled recycled aggregate concrete (MRAC) is calibrated using nanoindentation test results. The complete stress–strain curves, cracking process, and failure pattern of the numerical model are verified by the experimental results, proving their accuracy and validation. The initiation, growth, interaction, coalescence of microcracks, and subsequent macroscopic failure of the MRAC specimen are captured through DEM numerical simulations and compared with digital image correlation (DIC) results. The typical cracking modes controlled by meso-structures of MRAC are concluded according to numerical observations. A parameter study indicates the dominant influence of the macroscopic mechanical behaviors from the shear strength of the interfacial transition zones (ITZs).

Predicting Skin Friction and Heat Transfer for Turbulent Flow Over Real Gas-Turbine Surface Roughness Using the Discrete-Element Method

2003 ◽  
Author(s):  
Stephen T. McClain ◽  
B. Keith Hodge ◽  
Jeffrey P. Bons
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Wind Tunnel ◽  
Discrete Element Method ◽  
Skin Friction ◽  
Gas Turbine ◽  
Discrete Element ◽  
Real Gas ◽  
Roughness Elements ◽  
Element Method

The discrete-element method considers the total aerodynamic drag on a rough surface to be the sum of shear drag on the flat part of the surface and the form drag on the individual roughness elements. The total heat transfer from a rough surface is the sum of convection through the fluid on the flat part of the surface and the convection from each of the roughness elements. The discrete-element method has been widely used and validated for predicting heat transfer and skin friction for rough surfaces composed of sparse, ordered, and deterministic elements. Real gas-turbine surface roughness is different from surfaces with sparse, ordered, and deterministic roughness elements. Modifications made to the discrete-element roughness method to extend the validation to real gas-turbine surface roughness are detailed. Two rough surfaces found on high-hour gas-turbine blades were characterized using a Taylor-Hobson Form Talysurf Series 2 profilometer. Two rough surfaces and two elliptical-analog surfaces were generated for wind-tunnel testing using a three-dimensional printer. The printed surfaces were scaled to maintain similar boundary-layer thickness to roughness height ratio in the wind tunnel as found in gas-turbine operation. The results of the wind tunnel skin friction and Stanton number measurements and the discrete-element method predictions for each of the four surfaces are presented and discussed. The discrete-element predictions made considering the gas-turbine roughness modifications are within 7% of the experimentally-measured skin friction coefficients and are within 16% of the experimentally-measured Stanton numbers.

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