scholarly journals Macroscopic Behavior and Microscopic Structure Evolution of Marine Clay in One-Dimensional Compression Revealed by Discrete Element Simulation

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2259
Author(s):  
Lisha Luo ◽  
Zhifu Shen ◽  
Hongmei Gao ◽  
Zhihua Wang ◽  
Xin Zhou
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Formation Process ◽  
Discrete Element ◽  
Structure Evolution ◽  
Microscopic Structure ◽  
Marine Clay ◽  
Dem Simulation ◽  
One Dimensional ◽  
Simulation Scheme

Marine clay has been attracting in-depth research on its mechanical behavior and internal structure evolution, which are crucial to marine infrastructure safety. In the formation process of marine clay, including the sedimentation and consolidation stages, the compression behavior and internal structure evolution are highly dependent on the pore water salinity. Discrete element method (DEM) simulation is a powerful tool to study the microscopic mechanics behind the complicated macroscopic mechanical behavior of marine clay. In this study, a DEM simulation scheme is systematically proposed to numerically study the macroscopic beahvior and microscopic structure evolution of marine clay in one-dimensional compression that mimics the marine clay formation process. First, the proposed calculation scheme for double layer repulsive interaction and van der Waals interaction is introduced. Then, the developed DEM simulation scheme is validated by satisfactorily reproducing the experimentally observed one-dimensional compression curves and internal structure transition from an edge-to-edge/edge-to-face flocculated structure to a face-to-face dispersed structure. Finally, evolutions of coordinate number and fabric anisotropy are quantitatively evaluated in the microscopic view. The noticeable effects of ion concentration on the internal structure evlotion and mechanical behavior of marine clay have been examined and discussed.

scholarly journals Exploring the End-Liner Forces Using DEM Software

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1047
Author(s):  
Ngonidzashe Chimwani ◽  
Murray M. Bwalya
Keyword(s):  
Discrete Element Method ◽  
Size Distribution ◽  
Ball Milling ◽  
Discrete Element ◽  
Significant Cost ◽  
Cost Component ◽  
Dem Simulation ◽  
Ball Size ◽  
Ball Motion ◽  
Simulation Scheme

The main roles of liners are to protect the mill shell and promote effective ball motion for grinding. For this reason the liner profile is carefully selected to ensure that the productivity is maximized and due liner replacement is made when this objective is no longer met. These issues have been extensively studied on shell liners as mill relining is a significant cost component of ball milling. To date, not much has been written about end-liners and the kind of forces they are subjected to. A discrete element method (DEM) simulation scheme is conducted to look at how ball size distribution, mill filling, end-liner configuration and shape affect the distribution of forces acting on the liners that were assessed to understand end-liner wear and damage. The results showed how forces varied both radially and tangentially for the different sections of end-liner, with important insights drawn for end-liner manufactures.

DEM simulation of mechanical behavior in one-dimensional compression of crushable ceramic pebble bed

2021 ◽  
Vol 168 ◽  
pp. 112606
Author(s):  
Jian Wang ◽  
M.Z. Lei ◽  
S.L. Xu ◽  
H. Yang ◽  
P.H. Zhao ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Pebble Bed ◽  
Dem Simulation ◽  
One Dimensional

Kinetics of internal structure evolution in gypsum board exposed to standard fire

2013 ◽  
Vol 31 (5) ◽  
pp. 395-409 ◽  
Author(s):  
Amandine Rojo ◽  
Yannick Mélinge ◽  
Olivier Guillou
Keyword(s):  
Internal Structure ◽  
Structure Evolution ◽  
Gypsum Board ◽  
Standard Fire ◽  
Kinetics Of

Representation of Mechanical Behavior in the Presence of Changing Internal Structure

1988 ◽  
Vol 55 (1) ◽  
pp. 1-10 ◽  
Author(s):  
E. T. Onat ◽  
F. A. Leckie
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Applied Stress ◽  
Constitutive Equations ◽  
Creep Damage ◽  
Main Ideas ◽  
The Relationship ◽  
Small Deformations

The paper is concerned with the representation of the relationship that exists, for a given material and temperature and for small deformations, between histories of applied stress and the observed strain and the accompanying changes in internal structure of the material. Emphasis is given to creep damage in metals as a vehicle for illustration of the main ideas introduced in the paper. In particular, the role played by irreducible even rank tensors in the representation of internal structure is discussed and clarified. The restrictions placed by thermodynamics on constitutive equations are considered and the use of potentials in these equations is examined and criticized.

Mechanical response of double-stranded DNA to dynamic excitation

2021 ◽  
pp. 107754632110458
Author(s):  
Hamze Mousavi ◽  
Moein Mirzaei ◽  
Samira Jalilvand
Keyword(s):  
Mechanical Behavior ◽  
Mechanical Response ◽  
Actual Condition ◽  
Dimensional System ◽  
One Dimensional ◽  
Linear Elastic ◽  
Dynamic Excitation ◽  
Double Stranded Dna ◽  
Elastic Forces ◽  
Mass Spring

The present work investigates the vibrational properties of a DNA-like structure by means of a harmonic Hamiltonian and the Green’s function formalism. The DNA sequence is considered as a quasi one-dimensional system in which the mass-spring pairs are randomly distributed inside each crystalline unit. The sizes of the units inside the system are increased, in a step-by-step approach, so that the actual condition of the DNA could be modeled more accurately. The linear-elastic forces mimicking the bonds between the pairs are initially considered constant along the entire length of the system. In the next step, these forces are randomly shuffled so as to take into account the inherent randomness of the DNA. The results reveal that increasing the number of mass-spring pairs in the crystalline structure decreases the influence of randomness on the mechanical behavior of the structure. This also holds true for systems with larger crystalline units. The obtained results can be used to investigate the mechanical behavior of similar macro-systems.

scholarly journals Structure investigations of layered soil – varved clay

2016 ◽  
Vol 48 (4) ◽  
pp. 365-375 ◽  
Author(s):  
Matylda Tankiewicz
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Strength Properties ◽  
Layered Soil ◽  
Radiographic Images ◽  
Composition And Structure ◽  
Computed Microtomography ◽  
Structure Investigations ◽  
Varved Clay

Abstract In the paper the results of laboratory investigations of structure of layered soil are presented. They focus on varved clay that is a soil composed of two alternately arranged varves with different texture and mechanical properties. An effect of such structure is an anisotropy of the material. Due to varying conditions during its formation process the soil exhibits some irregularities in composition and structure. Due to that modelling of mechanical behavior, like strength, may not provide satisfactory results. Main purpose of the examinations is an investigation of internal structure of layered soil – varved clay – in relation to its strength anisotropy and evaluation of the suitability of the use of two different techniques to assess the soil structure. Investigated material have been taken from area near city of Bełchatów in central Poland. The examinations included investigation of particle size distribution of soil and its components, identification of lamination with use of scanning electron microscope (SEM) and computed microtomography technique (μCT). First, the texture of each varve and varved clay as a composite have been estimated. Next, the investigation of surface perpendicular to the lamination have been carried out with SEM. Pictures of varves with different magnifications are presented. Also the varves arrangement and details of layers contact area are shown. Finally, investigation of internal structure of the soil have been performed by using microtomograph. The outcome is a series of radiographic images and reconstructed 3D model of tested soil. Presented results show complexity of the structure of varved clay that affect the mechanical behavior. Determination of the structure with use of presented techniques may be helpful in examination of strength properties and proper modeling of such soil.

scholarly journals SIMULATION OF FRACTURE USING A MESH-DEPENDENT FRACTURE CRITERION IN THE DISCRETE ELEMENT METHOD

2018 ◽  
Vol 16 (1) ◽  
pp. 41 ◽  
Author(s):  
Andrey Dimaki ◽  
Evgeny Shilko ◽  
Sergey Psakhie ◽  
Valentin Popov
Keyword(s):  
Particle Size ◽  
Discrete Element Method ◽  
Mechanical Behavior ◽  
Fracture Criterion ◽  
Discrete Element ◽  
Macroscopic Behavior ◽  
Detachment Criterion ◽  
Discrete Element Methods ◽  
Adhesive Contacts ◽  
Fracture Processes

Recently, Pohrt and Popov have shown that for simulation of adhesive contacts a mesh dependent detachment criterion must be used to obtain the mesh-independent macroscopic behavior of the system. The same principle should be also applicable for the simulation of fracture processes in any method using finite discretization. In particular, in the Discrete Element Methods (DEM) the detachment criterion of particles should depend on the particle size. In the present paper, we analyze how the mesh dependent detachment criterion has to be introduced to guarantee the macroscopic invariance of mechanical behavior of a material. We find that it is possible to formulate the criterion which describes fracture both in tensile and shear experiments correctly.

Scalable synthesis of dual-confined SiO/one-dimensional carbon/amorphous carbon anode based on heterogeneous carbon structure evolution

2021 ◽  
Author(s):  
Hebang Shi ◽  
Guoqiang Shao ◽  
Binbin Wu ◽  
Zongxian Yang ◽  
Huigang Zhang ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Cycling Stability ◽  
Structure Evolution ◽  
Carbon Anode ◽  
Carbon Structure ◽  
One Dimensional ◽  
Scalable Synthesis ◽  
Confined Structure

The modification of dual carbon confined structure formed by one-dimensional carbon (1D-C) and amorphous carbon (a-C) exhibits great potentials in improving the cycling stability of SiO anodes. In order to...

scholarly journals Analysis of the Effect of Ventilation Bars on the Packing Structure of Sinter Bed by DEM Simulation

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3836
Author(s):  
Shingo Ishihara ◽  
Kizuku Kushimoto ◽  
Junya Kano
Keyword(s):  
Shear Flow ◽  
Discrete Element Method ◽  
Adhesion Force ◽  
Sinter Machine ◽  
Discrete Element ◽  
Angle Of Repose ◽  
Dem Simulation ◽  
Packing Structure ◽  
Experimental Values ◽  
Simulation Parameters

The effect of ventilation bars on the porosity of a sinter bed charged on a sinter machine was investigated. The behavior of the sinter feed was calculated by discrete element method (DEM) simulation. By taking into account the adhesion force, the sinter feed in the wet state was represented and the simulation parameters were determined to reproduce the experimental values of the angle of repose. The porosity of the sinter bed was calculated, and the mechanism of the formation of the packing structure and the cause of the distribution of porosity in each region were clarified. As a result, it is shown that in the case of shear flow, the higher the powder pressure during flow, the higher the porosity.

Internal structure evolution of L12 variants in aged Fe-Ga alloys

2020 ◽  
Vol 836 ◽  
pp. 155282 ◽  
Author(s):  
Junming Gou ◽  
Tianzi Yang ◽  
Xiaolian Liu ◽  
Tianyu Ma
Keyword(s):  
Internal Structure ◽  
Structure Evolution
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