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Article
Publication date: 9 October 2009

J. Kozicki and F.V. Donzé

YADE‐OPEN DEM is an open‐source software based on the discrete element method, (DEM) which uses object oriented programming techniques. The purpose of this paper is to describe…

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Abstract

Purpose

YADE‐OPEN DEM is an open‐source software based on the discrete element method, (DEM) which uses object oriented programming techniques. The purpose of this paper is to describe the software architecture.

Design/methodology/approach

The DEM chosen uses position, orientation, velocity and angular velocity as independent variables of simulated particles which are subject to explicit leapfrog time‐integration scheme (Lagrangian method). The three‐dimensional dynamics equations based on the classical Newtonian approach for the second law of motion are used. The track of forces and moments acting on each particle is kept at every time step. Contact forces depend on the particle geometry overlap and material properties. The normal, tangential and moment components of interaction force are included.

Findings

An effort is undertaken to extract the underlying object oriented abstractions in the DEM. These abstractions are implemented in C++, conform to object oriented design principles and use design patterns. Based on that, a software framework is developed in which the abstractions provide the interface where the modelling methods can be plugged‐in.

Originality/value

The resulting YADE‐OPEN DEM framework is designed in a generic way which provides great flexibility when adding new scientific simulation code. Some of the advantages are that numerous simulation methods can be coupled within the same framework while plug‐ins can import data from other software. In addition, this promotes code improvement through open‐source development and allows feedback from the community. However implementing such models requires that one adheres to the framework design and the YADE framework is a new emerging software. To download the software see http : //yade.wikia.com webpage.

Details

Engineering Computations, vol. 26 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 18 April 2017

Istvan Oldal, Ferenc Safranyik and Istvan Keppler

The purpose of this study is the reduction of computational time demand of discrete element based modeling.

87

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

Engineering Computations, vol. 34 no. 2
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 7 May 2020

Duzhou Zhang, Zhiguo Tian, Zhiqiang Chen, Dengyun Wu, Gang Zhou, Shaohua Zhang and Moran Wang

The purpose of this paper is to investigate the evolution of the permeability of spherical packing during cold compaction by pore-scale modeling.

115

Abstract

Purpose

The purpose of this paper is to investigate the evolution of the permeability of spherical packing during cold compaction by pore-scale modeling.

Design/methodology/approach

The discrete element method (DEM) is used to generate spherical packing structure under different compressive pressures and the Lattice Boltzmann method (LBM) is adopted to calculate the permeability of each spherical assembly.

Findings

It is found that the decrease of the porosity is the main reason of the reduction in permeability in the initial compression stage, but its influence becomes insufficient in the late compression stages. Besides, two empirical formulas are obtained, which describe the relation between the permeability and the equivalent mean diameter and the variation of normalized permeability with compressive pressure, respectively.

Research limitations/implications

In this study, the authors study the spherical particles and ignore the non-spherical effects. Besides, the classical contact model, the linear-spring-damping model, is used in DEM, so the plastic deformation cannot be considered.

Originality/value

The DEM and the LBM are well combined to study the compaction effects on permeability of spherical packing. Two simple expressions of the spherical packing structure with uniform diameter distribution are given for the first time.

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Article
Publication date: 9 November 2012

George K. Stylios

Examines the seventeenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

1179

Abstract

Examines the seventeenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 24 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 15 November 2011

George K. Stylios

Examines the sixteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects…

932

Abstract

Examines the sixteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Details

International Journal of Clothing Science and Technology, vol. 23 no. 6
Type: Research Article
ISSN: 0955-6222

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Article
Publication date: 19 July 2023

Yiwei Wang, Run Liu, Ruohan Sun and Zewei Xu

The paper aims to find the correlation between the microparameters and the macroparameters of the soil. The study aims to calibrate the macroscale and microscale parameters of…

121

Abstract

Purpose

The paper aims to find the correlation between the microparameters and the macroparameters of the soil. The study aims to calibrate the macroscale and microscale parameters of rolling resistance contact models to successfully apply the discrete element method to do some research of the geotechnical problem.

Design/methodology/approach

The paper opted for an exploratory study using the PFC3D to simulate the triaxial tests that include more than 50 cases and the coupling analysis method, which considering several effect of various factors.

Findings

The paper provides a quantitative relationship between the macroparameters and microparameters of the rolling resistance linear model and a method for fast calibration of macroscopic parameters is proposed and verified by a triaxial test example.

Originality/value

This paper provides the quantitative relationship of micro and macroparameters in the rolling resistance linear model by studying a single factor and considering the coupling effect of various factors and a fast method for the calibration of microparameters based on the rolling resistance linear model is proposed.

Details

Engineering Computations, vol. 40 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 February 2016

Mica Grujicic, Ramin Yavari, Jennifer Snipes and S Ramaswami

The recently proposed concept solution for improving blast-survivability of the light tactical military vehicles is critically assessed using combined…

162

Abstract

Purpose

The recently proposed concept solution for improving blast-survivability of the light tactical military vehicles is critically assessed using combined finite-element/discrete-particle computational methods and tools. The purpose of this paper is to propose a concept that involves the use of side-vent-channels attached to the V-shaped vehicle underbody. Since the solution does not connect the bottom and the roof or pass through the cabin of a light tactical vehicle, this solution is not expected to: first, reduce the available cabin space; second, interfere with the vehicle occupants’ ability to scout the surroundings; and third, compromise the vehicle’s off-road structural durability/reliability. Furthermore, the concept solution attempts to exploit ideas and principles of operation of the so-called “pulse detonation” rocket engines in order to create a downward thrust on the targeted vehicle.

Design/methodology/approach

To maximize the downward thrust effects and minimize the extent of vehicle upward movement, standard engineering-optimization methods and tools are employed for the design of side-vent-channels.

Findings

The results obtained confirmed the beneficial effects of the side-vent-channels in reducing the blast momentum, although the extent of these effects is relatively small (3-4 percent).

Originality/value

To the authors’ knowledge, the present work is the first public-domain report of the side-vent-channel blast-mitigation concept.

Details

International Journal of Structural Integrity, vol. 7 no. 1
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 6 February 2017

Mica Grujicic, Ramin Yavari, S. Ramaswami and Jennifer Snipes

The purpose of this paper is to carry out a design-optimization analysis of the recently proposed side-vent-channel concept/solution for mitigation of the blast loads resulting…

93

Abstract

Purpose

The purpose of this paper is to carry out a design-optimization analysis of the recently proposed side-vent-channel concept/solution for mitigation of the blast loads resulting from a shallow-buried mine detonated underneath a light tactical vehicle. Within this concept/solution, side-vent-channels attached to the V-shaped vehicle underbody are used to promote venting of ejected soil and supersonically expanding gaseous detonation products. This effect generates a downward thrust on the targeted vehicle, helping the vehicle survive mine-detonation-induced impulse loading.

Design/methodology/approach

The utility and the blast-mitigation capacity of this concept are investigated computationally using coupled finite-element/discrete-particle computational methods and tools. To maximize the blast-mitigation capacity of the solution (as defined by a tradeoff between the maximum reductions in the detonation-induced total momentum transferred to, and the acceleration acquired by, the target vehicle), the geometry and size of the side-vent-channel solution are optimized.

Findings

It is found that by optimizing the shape and size of the side-vent-channels, their ability to mitigate blast can be improved, but the overall blast-mitigation potential of the side-vent-channel solution remains relatively modest.

Originality/value

To the authors’ knowledge, the present work is the first attempt to combine the finite-element/discrete-particle analysis with optimization in order to refine the side-vent-channel blast-mitigation concept.

Details

International Journal of Structural Integrity, vol. 8 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Available. Content available
Article
Publication date: 25 October 2022

David Tae and Kumar K. Tamma

The purpose of this paper is to describe a novel implementation of a multispatial method, multitime-scheme subdomain differential algebraic equation (DAE) framework allowing a mix…

117

Abstract

Purpose

The purpose of this paper is to describe a novel implementation of a multispatial method, multitime-scheme subdomain differential algebraic equation (DAE) framework allowing a mix of different space discretization methods and different time schemes by a robust generalized single step single solve (GS4) family of linear multistep (LMS) algorithms on a single body analysis for the first-order nonlinear transient systems.

Design/methodology/approach

This proposed method allows the coupling of different numerical methods, such as the finite element method and particle methods, and different implicit and/or explicit algorithms in each subdomain into a single analysis with the GS4 framework. The DAE, which constrains both space and time in multi-subdomain analysis, combined with the GS4 framework ensures the second-order time accuracy in all primary variables and Lagrange multiplier. With the appropriate GS4 parameters, the algorithmic temperature rate variable shift can be matched for all time steps using the DAE. The proposed method is used to solve various combinations of spatial methods and time schemes between subdomains in a single analysis of nonlinear first-order system problems.

Findings

The proposed method is capable of coupling different spatial methods for multiple subdomains and different implicit/explicit time integration schemes in the GS4 framework while sustaining second-order time accuracy.

Originality/value

Traditional approaches do not permit such robust and flexible coupling features. The proposed framework encompasses most of the LMS methods that are second-order time accurate and unconditionally stable.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

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Article
Publication date: 22 February 2013

Francisco Montero‐Chacón and Fernando Medina

The purpose of this paper is to determine the representative volume element (RVE) size for quasi‐brittle materials using a discrete approach, namely a lattice‐particle model.

350

Abstract

Purpose

The purpose of this paper is to determine the representative volume element (RVE) size for quasi‐brittle materials using a discrete approach, namely a lattice‐particle model.

Design/methodology/approach

Different material samples are generated and subjected to study regarding its size, maximum aggregate size and boundary conditions. In order to determine the mechanical properties such as the elastic modulus, Poisson's ratio or tensile strength, several tension tests are carried out. For this purpose, a lattice‐particle approach is used to model concrete's fracturing behavior. The information provided by the previous simulations is implemented in a statistical analysis to determine the size of the RVE.

Findings

The determination of the RVE size for quasi‐brittle materials is successfully achieved by means of a lattice‐particle model. Computed results show a good agreement with other results reported in the bibliography.

Originality/value

Within a general multiscale framework, the determination of the RVE size is of great interest and some studies have been performed for random heterogeneous materials. However, these analyses are mainly continuum‐based. The estimation of the RVE size is important for correctly predicting the mechanical properties and can be used in different multiscale schemes.

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