scholarly journals Probabilistic Analysis of the Hard Rock Disintegration Process

10.14311/1041 ◽  
2008 ◽  
Vol 48 (4) ◽  
Author(s):  
K. Frydrýšek
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Hard Rock ◽  
Assessment Method ◽  
Contact Forces ◽  
Disintegration Process ◽  
Long Time ◽  
Structural Nonlinearities ◽  
Reaction Forces ◽  
Mathcad Software

This paper focuses on a numerical analysis of the hard rock (ore) disintegration process. The bit moves and sinks into the hard rock (mechanical contact with friction between the ore and the cutting bit) and subsequently disintegrates it. The disintegration (i.e. the stress-strain relationship, contact forces, reaction forces and fracture of the ore) is solved via the FEM (MSC.Marc/Mentat software) and SBRA (Simulation-Based Reliability Assessment) method (Monte Carlo simulations, Anthill and Mathcad software). The ore is disintegrated by deactivating the finite elements which satisfy the fracture condition. The material of the ore (i.e. yield stress, fracture limit, Young’s modulus and Poisson’s ratio), is given by bounded histograms (i.e. stochastic inputs which better describe reality). The results (reaction forces in the cutting bit) are also of stochastic quantity and they are compared with experimental measurements. Application of the SBRA method in this area is a modern and innovative trend in mechanics. However, it takes a long time to solve this problem (due to material and structural nonlinearities, the large number of elements, many iteration steps and many Monte Carlo simulations). Parallel computers were therefore used to handle the large computational needs of this problem. 

scholarly journals Numerical solution of hard rock disintegration process – part 2

2012 ◽  
Vol 58 (3) ◽  
pp. 39-46
Author(s):  
Karel Frydrýšek
Keyword(s):  
Monte Carlo ◽  
Hard Rock ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Assessment Method ◽  
Deterministic Approach ◽  
Disintegration Process ◽  
Stochastic Inputs ◽  
Simulation Based ◽  
Rock Disintegration

Abstract This paper focuses on a numerical analysis of a hard rock (ore) disintegration process. A bit moves into the ore and subsequently disintegrates it. The disintegration (i.e. fracture of ore) is solved via a deterministic approach (FEM) and a probabilistic approach (FEM in combination with the SBRA - Simulation-Based Reliability Assessment method, i.e. Monte Carlo simulations, stochastic inputs). The ore is disintegrated by deactivating the finite elements satisfying fracture conditions. The results are compared with experiments. The application of the SBRA method is a new and innovative trend in this area. Finally, the probabilistic reliability assessment is mentioned.

scholarly journals Assessing the Economic Risk of Building Damage due to the Tunneling-Induced Settlement Using Monte Carlo Simulations and BIM

2020 ◽  
Vol 12 (23) ◽  
pp. 10034
Author(s):  
Stylianos Providakis ◽  
Chris D. F. Rogers ◽  
David N. Chapman
Keyword(s):  
Decision Making ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Assessment Method ◽  
Building Damage ◽  
Analytical Models ◽  
Integrated Analysis ◽  
Economic Damage ◽  
Economic Risk ◽  
Advanced Analysis

Due to the increasing use of underground space to align with sustainability needs, geohazard risk assessments have become a valuable tool for decision-making. One common issue in relation to urban geohazard assessments relates to ground movements due to tunneling affecting adjacent buildings. A framework for assessing costs related to subsequent building damage, using integrated data, statistics and considering the uncertainties involved, is presented in this paper. The proposed methodology provides an integration of Monte Carlo simulations to support uncertainty estimations with an analysis for building-damage cost risk due to tunneling-induced settlements. The analysis involves analytical models using green-field conditions and a typically used building damage assessment method. BIM is capable of collating, combining and visualizing information with advanced analysis techniques into a risk-based tool. The resulting tool provides a clear way of assessing building-damage costs risk due to tunneling-induced settlements. This uses a BIM-based environment and incorporates 3D visualizations and an integrated analysis via MATLAB to reveal and highlight hazardous areas and the severity of economic risk along the tunneling route. This informs the need for additional ground investigations or secondary analyses to ensure engineering processes reduce or remove the risk of economic damage and advance sustainable decision-making.

scholarly journals Effects of homophily and heterophily on preferred-degree networks: mean-field analysis and overwhelming transition

2022 ◽  
Vol 2022 (1) ◽  
pp. 013402
Author(s):  
Xiang Li ◽  
Mauro Mobilia ◽  
Alastair M Rucklidge ◽  
R K P Zia
Keyword(s):  
Field Theory ◽  
Monte Carlo ◽  
Social Interaction ◽  
Monte Carlo Simulations ◽  
Network Structure ◽  
Mean Field Theory ◽  
Mean Field ◽  
Field Analysis ◽  
Long Time

Abstract We investigate the long-time properties of a dynamic, out-of-equilibrium network of individuals holding one of two opinions in a population consisting of two communities of different sizes. Here, while the agents’ opinions are fixed, they have a preferred degree which leads them to endlessly create and delete links. Our evolving network is shaped by homophily/heterophily, a form of social interaction by which individuals tend to establish links with others having similar/dissimilar opinions. Using Monte Carlo simulations and a detailed mean-field analysis, we investigate how the sizes of the communities and the degree of homophily/heterophily affect the network structure. In particular, we show that when the network is subject to enough heterophily, an ‘overwhelming transition’ occurs: individuals of the smaller community are overwhelmed by links from the larger group, and their mean degree greatly exceeds the preferred degree. This and related phenomena are characterized by the network’s total and joint degree distributions, as well as the fraction of links across both communities and that of agents having fewer edges than the preferred degree. We use our mean-field theory to discuss the network’s polarization when the group sizes and level of homophily vary.

scholarly journals RISE OF THE CENTRIST: FROM BINARY TO CONTINUOUS OPINION DYNAMICS

2008 ◽  
Vol 19 (09) ◽  
pp. 1459-1475 ◽  
Author(s):  
GEORGE A. BAKER ◽  
JAMES P. HAGUE
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Continuum Limit ◽  
Linear Chain ◽  
Opinion Dynamics ◽  
Memory Effects ◽  
Time Step ◽  
Binary Model ◽  
Long Time ◽  
The Continuum

We propose a model that extends the binary "united we stand, divided we fall" opinion dynamics of Sznajd-Weron to handle continuous and multi-state discrete opinions on a linear chain. Disagreement dynamics are often ignored in continuous extensions of the binary rules, so we make the most symmetric continuum extension of the binary model that can treat the consequences of agreement (debate) and disagreement (confrontation) within a population of agents. We use the continuum extension as an opportunity to develop rules for persistence of opinion (memory). Rules governing the propagation of centrist views are also examined. Monte Carlo simulations are carried out. We find that both memory effects and the type of centrist significantly modify the variance of average opinions in the large timescale limits of the models. Finally, we describe the limit of applicability for Sznajd-Weron's model of binary opinions as the continuum limit is approached. By comparing Monte Carlo results and long time-step limits, we find that the opinion dynamics of binary models are significantly different to those where agents are permitted more than 3 opinions.

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