scholarly journals Effect of the Soft and Hard Interbedded Layers of Bedrock on the Mechanical Characteristics of Stabilizing Piles

2020 ◽  
Vol 10 (14) ◽  
pp. 4760
Author(s):  
Manman Dong ◽  
Liangqing Wang ◽  
Babak Shahbodagh ◽  
Xi Du ◽  
Shan Deng ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Maximum Displacement ◽  
Stabilizing Piles ◽  
Simulation Results ◽  
Dip Angle ◽  
Comparison With Experimental Data

In this paper, the mechanical characteristics of stabilizing piles embedded in layered bedrocks are studied both experimentally and numerically. The influence of soft and hard interbedded layers in the structure of the bedrock on the mechanical characteristics of stabilizing piles is particularly investigated. The discrete element method is used to numerically investigate the response of the stabilizing piles embedded in composite and inclined bedrocks. The simulation results and comparison with experimental data are presented to demonstrate the effectiveness and accuracy of the discrete element model. As the dip angle of the soft/hard interbedded bedrock layers increases from 0° to 45°, it is observed that the displacement of the embedded section of the stabilizing pile increases and reaches the maximum displacement at 45°. In the range of 45° to 75°, the influence of the dip angle of the layered bedrock on the displacement of the embedded section of the pile is gradually reduced.

A Wear Simulation of the Fixed Soft Abrasive Film Based on Discrete Element Method

2014 ◽  
Vol 1017 ◽  
pp. 452-457
Author(s):  
Zhao Zhong Zhou ◽  
Kai Ping Feng ◽  
Ju Long Yuan
Keyword(s):  
Element Model ◽  
Discrete Element ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Discrete Element Model ◽  
Optic Fiber ◽  
Wear Property ◽  
Factors Affecting ◽  
Main Factors ◽  
Simulation Results

A new polishing method by using fixed soft abrasive film is proposed to polish the end-face of the optic fiber connector. In order to study the wear property of the fixed soft abrasive film, the Particle Flow Code program was employed to simulate the interaction of surface topography. The discrete element model of the optic fiber connector and the fixed soft abrasive film were established. Through the interaction of the surface of two models, the process of contact and friction between the fixed soft abrasive film and the end-face of the optic fiber connector could be simulated. Simulation results showed that the main factors affecting the wear of the fixed soft abrasive film were pressure and speed, which mainly affected the normal stress and the tangential stress respectively. And the wear of the surface was mainly related to pressure and speed. The greater the speed and pressure were, the more serious wear of the fixed soft abrasive film was.

Numerical Simulation of Sea Ice Compressional Strength with Discrete Element Model

2011 ◽  
Vol 268-270 ◽  
pp. 913-918
Author(s):  
Hai Li ◽  
Yu Liu ◽  
Xiang Jun Bi ◽  
Shun Ying Ji
Keyword(s):  
Experimental Data ◽  
Sea Ice ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Offshore Structure ◽  
Ice Load ◽  
Particle Bonding ◽  
Compressional Strength ◽  
Key Parameter

The compressional strength of sea ice is a key parameter to determine the interaction between ice cover and offshore structure. In this study, the discrete element model (DEM) with particle bonding function is adopted to model the sea ice compressional strength. The bonding strength is set as a function of the ice temperature and ice salinity, and their influences on sea ice compressional strength are observed. The simulated results are compared well with the physical experimental data. With the improvement of this DEM, the ice load and ice-induced vibration of offshore structure can be simulated.

A Discrete Element Approach to Model Breakable Railway Ballast

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
Christian Ergenzinger ◽  
Robert Seifried ◽  
Peter Eberhard
Keyword(s):  
Experimental Data ◽  
Element Model ◽  
Discrete Element ◽  
Quantitative Agreement ◽  
Discrete Element Model ◽  
Compression Tests ◽  
Railway Ballast ◽  
Element Approach ◽  
Strong Rock ◽  
Granular Solid

A discrete element approach to assess degradation processes in ballast beds is presented. Firstly, a discrete element model describing strength and failure of strong rock is introduced. For this purpose a granular solid is created by bonding of adjacent particles. A method to define angular ballast stones made from the granular solid is proposed. The strength of these stones is evaluated by compression between parallel platens. Comparing these results to published experimental data yields very good qualitative and reasonable quantitative agreement. Finally, the failure of aggregates of breakable stones is investigated by simulation of oedometric compression tests and indentation of a sleeper into a ballast bed.

scholarly journals A Quantitative Discrete Element Model to Investigate Sub-Surface Damage due to Surface Polishing

2012 ◽  
Author(s):  
Damien André ◽  
Ivan Iordanoff ◽  
Jean-luc Charles ◽  
Jérôme Néauport
Keyword(s):  
Experimental Data ◽  
Silica Glass ◽  
Surface Damage ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Continuous Part ◽  
Surface Polishing ◽  
Quantitative Results ◽  
Good Agreement

This work is a continuation of a previous study that investigated sub-surface damage in silica glass due to surface polishing. In this previous study, discrete element models have shown qualitatively good agreement with experiments. The presented work propose a model allowing quantitative results by focusing on the continuous part of the problem. Special attemption was given to the discrete element model of silica glass considered as perfectly isotropic, elastic and brittle. To validate this approach, numerical results are compared to experimental data from literature.

Simulation of Floating Debris during a Flash Flood Event

2020 ◽  
Author(s):  
Liang Qiuhua ◽  
Yan Xiong ◽  
Gang Wang
Keyword(s):  
Shallow Water ◽  
Hydrodynamic Model ◽  
Shallow Water Equations ◽  
Flash Flood ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Intense Rainfall ◽  
Flash Flooding ◽  
Simulation Results

<p>Under climate change, extreme weather events such as storms and intense rainfall has become far more frequent. This is evidenced by the outburst of multiple flood events in the recent years in the UK and other parts of the world. Induced by intense rainfall, flash flooding is one type of wide-spread natural hazards that can pose serious threats to people’s lives and properties. Most likely happening in steep rapid-response catchments following localized high intensity rainfall, flash floods are characterized by rapid rise of water level and high flow velocities in channels and floodplains. The violent flood waves can remove and transport heavy objects such as cars and tree, imposing extra risk to people and infrastructure, e.g. bridges.</p><p>On 16<sup>th</sup> August 2004, the coastal village of Boscastle in north Cornwall, UK, was devastated by a flash flood following an exceptional amount of rain that fell over eight hours. The village suffered extensive damage and notably, some 100 vehicles were washed to downstream and into the sea, some of which blocked bridges and altered flood hydraulics. This work aims to reproduce the flood event including floating debris dynamics using a new coupled hydrodynamic model. The coupled modelling tool predicts the flooding process using a finite volume shock-capturing model that solves the fully 2D shallow water equations (SWEs), which is coupled with a discrete element model (DEM) to simulate the interactive dynamics of floating objects. The coupled model is further accelerated by implementation on modern GPUs and is therefore well-suited for simulation of large-scale transient flood hydrodynamics enriched with floating debris. The simulation results are first confirmed by comparing with maximum flood depths collected after the event. Further simulations are carried out to investigate the influence of floating vehicles on flood hydrodynamics and understand how they block bridges and alter flood paths. The simulation results are consistent with observations captured during the event.</p><p><strong>Key Words</strong>: Flash flooding; Hydrodynamic model; Shallow water equations; Discrete element model; Floating debris</p>

scholarly journals Discrete element model for general polyhedra

2021 ◽  
Author(s):  
Alfredo Gay Neto ◽  
Peter Wriggers
Keyword(s):  
Frictional Contact ◽  
Virtual Work ◽  
Particle Surface ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Principle Of Virtual Work ◽  
Dynamics Model ◽  
Railway Ballast ◽  
Multibody Dynamics Model

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.

scholarly journals Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 875
Author(s):  
Jie Wu ◽  
Yuri Hovanski ◽  
Michael Miles
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Numerical Model ◽  
Plastic Strain ◽  
Finite Element Model ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
Dome Height ◽  
Tailor Welded Blanks ◽  
Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

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