scholarly journals Review on Numerical Simulation of the Internal Soil Erosion Mechanisms Using the Discrete Element Method

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 169
Author(s):  
Xiukai Wang ◽  
Yao Tang ◽  
Bo Huang ◽  
Tiantian Hu ◽  
Daosheng Ling
Keyword(s):  
Numerical Simulation ◽  
Soil Erosion ◽  
Erosion Resistance ◽  
Internal Erosion ◽  
Force Chains ◽  
Erosion Process ◽  
Geometric Conditions ◽  
Hydraulic Conditions ◽  
Erosion Mechanisms ◽  
The Stability

Internal erosion can trigger severe engineering disasters, such as the failure of embankment dams and uneven settlement of buildings and sinkholes. This paper comprehensively reviewed the mechanisms of soil internal erosion studied by numerical simulation, which can facilitate uncovering the internal erosion mechanism by tracing the movement of particles. The initiation and development of internal erosion are jointly influenced by the geometric, mechanical, and hydraulic conditions, which determine the pore channels and force chains in soil. The geometric conditions are fundamental to erosion resistance, whereas the mechanical conditions can significantly change the soil erosion resistance, and the hydraulic conditions determine whether erosion occurs. The erosion process can be divided into particle detachment, transport, and clogging. The first is primarily affected by force chains, whereas the latter two are mostly affected by the pore channels. The stability of the soil is mainly determined by force chains and pore channels, whereas the hydraulic conditions act as external disturbances. The erosion process is accompanied by contact failure, force chain bending, kinetic energy burst of particles, and other processes due to multi-factor coupling.

INVESTIGATION OF EROSION RESISTANCE OF GRAY-BROWN SOILS IN THE SOUTHEASTERN SLOPES OF THE GREATER CAUCASUS

2020 ◽  
pp. 47-49
Author(s):  
Aliyev Z.H.
Keyword(s):  
Erosion Resistance ◽  
Preventive Measures ◽  
Chemical Properties ◽  
Anthropogenic Factors ◽  
Erosion Process ◽  
Greater Caucasus ◽  
Sloping Lands ◽  
Set Up ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, sharp changes have occurred in the state of sloping lands of Azerbaijan. There was tension from the influence of the anthropogenic factors on the mountain slopes. The fact that the erosion process is rein-forced in the research site. Due to lack of agrotechnical measures on the slopes erosion process has been strength-ened, soil flooded with soil, physical and chemical properties of the soil have deteriorated, nutritional elements are reduced, vegetation is reduced and destruction limit. For some reason, the purpose of the research was Aqsu, two land cuts were set up to determine the degree of actual erosion in the Qizmeydan village. prevent erosion intensity, take preventive measures to take and implement appropriate measures.

scholarly journals Force chains in crystalline and frustrated packings of uniform spheres visualized by stress-birefringence

Soft Matter ◽  
2021 ◽  
Author(s):  
David Fischer ◽  
Ralf Stannarius ◽  
Karsten Tell ◽  
Peidong Yu ◽  
Matthias Sperl
Keyword(s):  
Granular Material ◽  
Force Chains ◽  
Force Networks ◽  
The Stability

Force networks play an important role in the stability of configurations when granular material is packed into a container. These networks can redirect part of the weight of grains inside...

STABILITY OF TWO TYPICAL COMPLEX DYNAMICAL NETWORKS

2008 ◽  
Vol 22 (05) ◽  
pp. 553-560 ◽  
Author(s):  
WU-JIE YUAN ◽  
XIAO-SHU LUO ◽  
PIN-QUN JIANG ◽  
BING-HONG WANG ◽  
JIN-QING FANG
Keyword(s):  
Numerical Simulation ◽  
Dissipative System ◽  
Small World ◽  
Complex Dynamical Networks ◽  
Dynamical Networks ◽  
Scale Free ◽  
Scale Free Networks ◽  
General Complex ◽  
The Stability ◽  
Theoretical Results

When being constructed, complex dynamical networks can lose stability in the sense of Lyapunov (i. s. L.) due to positive feedback. Thus, there is much important worthiness in the theory and applications of complex dynamical networks to study the stability. In this paper, according to dissipative system criteria, we give the stability condition in general complex dynamical networks, especially, in NW small-world and BA scale-free networks. The results of theoretical analysis and numerical simulation show that the stability i. s. L. depends on the maximal connectivity of the network. Finally, we show a numerical example to verify our theoretical results.

The Compliance Method for Measurement of Near Surface Residual Stresses—Analytical Background

1994 ◽  
Vol 116 (4) ◽  
pp. 550-555 ◽  
Author(s):  
M. Gremaud ◽  
W. Cheng ◽  
I. Finnie ◽  
M. B. Prime
Keyword(s):  
Numerical Simulation ◽  
Residual Stresses ◽  
Random Errors ◽  
Residual Stress Field ◽  
Near Surface ◽  
Surface Residual Stresses ◽  
Zero Shift ◽  
Stress States ◽  
The Stability ◽  
Piecewise Functions

Introducing a thin cut from the surface of a part containing residual stresses produces a change in strain on the surface. When the strains are measured as a function of the depth of the cut, residual stresses near the surface can be estimated using the compliance method. In previous work, the unknown residual stress field was represented by a series of continuous polynomials. The present paper shows that for stress states with steep gradients, superior predictions are obtained by using “overlapping piecewise functions” to represent the stresses. The stability of the method under the influence of random errors and a zero shift is demonstrated by numerical simulation.

Basic Experimental and Numerical Investigations on Chip Pressing

2013 ◽  
Vol 554-557 ◽  
pp. 630-637 ◽  
Author(s):  
Martin Grüner ◽  
Marion Merklein
Keyword(s):  
Numerical Simulation ◽  
Aluminium Alloys ◽  
Testing Machine ◽  
Material Model ◽  
Extrusion Process ◽  
Milling Process ◽  
Numerical Investigations ◽  
Compression Direction ◽  
Universal Testing ◽  
The Stability

Aluminium alloys show a great potential for lightweight constructions due to their high strength and low density but the production of this material is very energy consuming. Also the recycling of aluminium alloys, e.g. chips from the milling process, shows different challenges. Beside contamination by cooling lubricant and oxidation of the surface of the chips the melting and rolling process for new semi finish products needs a high amount of energy. TEKKAYA shows a new approach for recycling of aluminium alloy chips by an extrusion process at elevated temperatures producing different kinds of profiles. A new idea is the production of components directly out of chips using severe plastic deformation for joining of the chips similar to the accumulative roll bonding process in sheet metal forming. In a first approach aluminium alloy chips out of a milling process were uniaxial compressed with different loads inside an axisymmetric tool installed in a universal testing machine. The compressed chip disks subsequently were tested with two experiments to gain information on their stability. First experiment is a disk compression test with the disk standing on its cylindrical surface, giving information on the stability perpendicular to the compression direction. Second experiment is a stacked disk compression test with three disks to investigate the stability parallel to compression direction. During all three tests force and displacement values are recorded by the universal testing machine. These data are also processed to calculate or identify input parameters for the numerical investigations. For numerical simulation ABAQUS in conjunction with the Drucker-Prager-Cap material model, which is often used for sintering processes, seems to be a good choice. By numerical simulation of the experiments and comparison with the experiments input parameters for the material model can be identified showing good accordance. This material model will be used in future numerical investigations of an extrusion process to identify tool geometries leading to high strains inside the material and by this to an increased stability of the parts.

Application of ABAQUS in Surrounding Rock Stability Analysis of Shallow Large Cross-Section Tunnel

2015 ◽  
Vol 777 ◽  
pp. 8-12 ◽  
Author(s):  
Lin Zhen Cai ◽  
Cheng Liang Zhang
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strong Support ◽  
Surrounding Rock ◽  
Tunnel Engineering ◽  
Tunnel Excavation ◽  
Rock Stability ◽  
Rock Bolting ◽  
Excavation Support ◽  
The Stability

HuJiaDi tunnel construction of Dai Gong highway is troublesome, the surrounding-rock mass give priority to full to strong weathering basalt, surrounding rock integrity is poor, weak self-stability of surrounding rock, and tunnel is prone to collapse. In order to reduce disturbance, taking advantage of the ability of rock mass, excavation adopt the method of "more steps, short footage and strong support". The excavation method using three steps excavation, The excavation footage is about 1.2 ~ 1.5 m; The surrounding rock bolting system still produce a large deformation after completion of the first support construction, it shows that the adopted support intensity cannot guarantee the stability of the tunnel engineering. Using ABAQUS to simulate tunnel excavation support, optimizing the support parameters of the tunnel, conducting comparative analysis with Monitoring and Measuring and numerical simulation results, it shows that the displacement - time curves have a certain consistency in numerical simulation of ABAQUS and Monitoring and Measuring.

Some Relationship between Safety Factor of Earthquake Slope and Related Parameters

2011 ◽  
Vol 422 ◽  
pp. 688-692
Author(s):  
Xiao Hei He ◽  
Geng You Han ◽  
Rui Hua Xiao
Keyword(s):  
Numerical Simulation ◽  
Rock Mechanics ◽  
Safety Factor ◽  
Limit Equilibrium ◽  
Static Method ◽  
Acceleration Coefficient ◽  
The Wenchuan Earthquake ◽  
Stability Of Slope ◽  
The Stability ◽  
The Relationship

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.

Influence of Force Chains Behaviors on Strength of Al/W/PTFE Granular Composite

2021 ◽  
Vol 324 ◽  
pp. 94-99
Author(s):  
Le Tang ◽  
Die Hu ◽  
Sheng Zhou ◽  
Chao Ge ◽  
Hai Fu Wang ◽  
...  
Keyword(s):  
Random Distribution ◽  
Force Chains ◽  
Metal Particles ◽  
Fracture Mechanisms ◽  
Mesoscale Simulation ◽  
Dynamic Simulations ◽  
Granular Composite ◽  
Compressive Response ◽  
Cracks Propagation ◽  
The Stability

Mesoscale simulation is conducted to investigate the effect of force chains between metal particles on the mechanical behavior of aluminum-tungsten-polytetrafluoroethylene (Al/W/PTFE) granular composite under a strain-controlled loading. A two-dimensional model followed the random distribution of particles is developed. Dynamic simulations are performed with variations in the size of Al particles to reveal the strength and fracture mechanisms of the composites. The results indicate that, force chains governed by the number and the size of metal particles significantly affects the global compressive response and macro-cracks propagation. The stability and reconstruction of mesoscale force chains explain the phenomenon that a higher strength is observed in the material with fine Al particles. Combined with the angle between particles, we examine the properties of force chains and the network as they evolve during the course of the deformation. Findings indicate that reactive composites tend to produce shorter chains, and straighter force chains with a smaller force angle result in a macroscopically stronger granular material.

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