scholarly journals Analysis Of Methods And Means Of Bump Hazard Prediction

2021 ◽  
Vol 03 (04) ◽  
pp. 47-54
Author(s):  
Sayyidkosimov ` S.S. ◽  
◽  
Kazakov. A.N ◽  
Khakberdiev M.R. ◽  
Tursunbayev D.A. ◽  
...  
Keyword(s):  
Rock Mass ◽  
Underground Mining ◽  
A Priori ◽  
Field Studies ◽  
Gold Deposits ◽  
The Finite Element Method ◽  
The Core ◽  
Core Disking ◽  
The Impact ◽  
Element Method

The article analyzes the methods and tools for predicting the impact hazard in the conditions of underground mining of gold deposits. To assess the stress state of a rock mass, the core disking method is proposed as a basic method. The degree and categories of impact hazard of sections of the rock mass are estimated. Due to the impossibility of solving many problems by geomechanical only field studies. The reliable efficiency of the use of the finite element method and the boundary element method in predicting the impact hazard of the field sites a priori is shown.

Philosophy of Economics

2018 ◽  
Author(s):  
Mikaël Cozic
Keyword(s):  
Behavioral Economics ◽  
Mathematical Models ◽  
A Priori ◽  
The Core ◽  
Philosophy Of Economics ◽  
Empirical Significance ◽  
Bona Fide ◽  
The Impact ◽  
Empirical Methodology ◽  
Recent Extension

Although there are no doubts regarding the impact of economics in society and politics, doubts regarding its epistemological status endure. Does economics provide us with bona fide empirical theories? Are its mathematical models on a par with those of the hard sciences, or is its scientific character exaggerated? This chapter focuses on the key problem of the philosophy of economics: the reconciliation of its claim to empirical significance with what often appears as a non-empirical methodology, favoring deduction from a priori principles and showing little sensitivity to refutation by observation and experiment. Several attempts at answering this problem are considered, both in the Millian tradition and following neo-positivist approaches. Finally, the empirical status of the discipline is put in perspective with its recent extension to new fields of inquiry, such as behavioral economics and neuroeconomics, where experiments seem to be part of the core methodology.

Mathematical Simulation of Rigid Pile Composite Foundation with Lateral Unloading

2013 ◽  
Vol 368-370 ◽  
pp. 756-759
Author(s):  
Jing Ma ◽  
Wen Sheng Chen ◽  
Xue Feng Hu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mathematical Simulation ◽  
Horizontal Displacement ◽  
Composite Foundation ◽  
The Finite Element Method ◽  
Rigid Pile ◽  
Rigid Pile Composite Foundation ◽  
The Impact ◽  
Element Method

Based on the Finite Element Method ,a model has been built to study the impact of rigid pile composite foundation with lateral unloading,then obtained a conclusion about the horizontal displacement during excavating.

scholarly journals BEM and FEM results of displacements in a poroelastic column

2012 ◽  
Vol 22 (4) ◽  
pp. 883-896 ◽  
Author(s):  
Bettina Albers ◽  
Stavros A. Savidis ◽  
H. Ercan Taşan ◽  
Otto von Estorff ◽  
Malte Gehlken
Keyword(s):  
Finite Element Method ◽  
Permeability Coefficient ◽  
Analytic Solution ◽  
The Finite Element Method ◽  
Practical Applications ◽  
Poroelastic Media ◽  
Two Component ◽  
Solution Methods ◽  
The Impact ◽  
Element Method

The dynamical investigation of two-component poroelastic media is important for practical applications. Analytic solution methods are often not available since they are too complicated for the complex governing sets of equations. For this reason, often some existing numerical methods are used. In this work results obtained with the finite element method are opposed to those obtained by Schanz using the boundary element method. Not only the influence of the number of elements and time steps on the simple example of a poroelastic column but also the impact of different values of the permeability coefficient is investigated.

scholarly journals Optimization Procedure of Roller Elements Geometry with Regard to Durability of Spherical Roller Bearings

2020 ◽  
Vol 22 (2) ◽  
pp. 68-72
Author(s):  
Jan Steininger ◽  
Stefan Medvecky ◽  
Robert Kohar ◽  
Tomas Capak
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Roller Bearing ◽  
Optimization Procedure ◽  
Parametric Models ◽  
The Finite Element Method ◽  
Roller Bearings ◽  
Contact Points ◽  
The Impact ◽  
Element Method

The article deals with an optimization procedure of roller elements geometry with regard to durability of spherical roller bearings. The aim of the article is to examine the impact of change of the roller elements inner geometry on durability and reliability of spherical roller bearings; the contact strain along a spherical roller by means of the Finite Element Method at contact points of components of a spherical roller bearing by means of designed 3D parametric models. The most appropriate shape of roller elements inner geometry of a bearing from the standpoint of calculated durability was determined based on results of the contact analyses.

Engineering Calculations of Microelectronic Products Parts and Assemblies Using Finite-Element Modeling

2021 ◽  
Vol 26 (3-4) ◽  
pp. 255-264
Author(s):  
E.Y. Chugunov ◽  
◽  
A.I. Pogalov ◽  
S.P. Timoshenkov ◽  
◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Properties ◽  
Integrated Approach ◽  
Design And Technology ◽  
Design Parameters ◽  
The Finite Element Method ◽  
Operational Factors ◽  
The Impact ◽  
Element Method

In the context of increasing the electronic components integration level, growing functionality and packaging density, as well as reducing the electronics weight and size, an integrated approach to engineering calculations of parts and assemblies of modern functionally and technically complex microelectronic products is required. Of particular importance are engineering calculations and structural modeling using computer-aided engineering systems, and also assessment of structural, technological and operational factors’ impact on the products reliability and performance. This work presents an approach to engineering calculations and microelectronic products modeling based on the finite-element method providing a comprehensive account of various factors (material properties, external loading, temperature fields, and other parameters) impact on the stress-strain state, mechanical strength, thermal condition, and other characteristics of products. On the example of parts and assemblies of products of microelectronic technology, the approximation of structures was shown and computer finite-element models were developed to study various structural and technological options of products and the effects on them. Engineering calculations and modeling of parts and assemblies were performed, taking into account the impact of material properties, design parameters and external influences on the products’ characteristics. Scientific and technical recommendations for structure optimization and design and technology solutions ensuring the products resistance to diverse effects were developed. It has been shown that an integrated approach to engineering calculations and microelectronic products modeling based on the finite-element method provides for the determination of optimal solutions taking into account structural, technological, and operational factors and allows the development of products with high tactical, technical and operational characteristics.

Propagation of Regular HCl Acids in Carbonate Rocks: The Impact of an In Situ Gelled Acid Stage

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Ahmed M. Gomaa ◽  
Hisham A. Nasr-El-Din
Keyword(s):  
Material Balance ◽  
Chemical Species ◽  
Field Studies ◽  
Injection Rate ◽  
The Core ◽  
The Impact ◽  
First Time ◽  
Recent Laboratory ◽  
Injection Rates

Recent laboratory and field studies indicated that polymer-based in situ gelled acids can cause formation damage. Coreflood experiments using single-stage and multistage acids were conducted at 250 °F. 15 wt. % regular HCl and 5 wt. % in situ gelled acid-based on Fe(III) as a crosslinker were the acids that were used in this study. Propagation of acids and crosslinker inside 20 in. long cores was examined for the first time in detail. Stage volume and injection rate, which were the parameters that affect the propagating of various chemical species, were examined. Samples of the core effluent were collected and the concentrations of calcium, crosslinker, and acid were measured. Material balance was conducted to determine the amount of cross-liker that retained in the core. The results show that in situ gelled acid should be pumped at low injection rates. In situ gelled acid at low injection rate instantaneously plugged the tip of the wormhole and did not create additional wormholes inside the core. Therefore, when the final regular acid stage bypassed the gel, it started to propagate from nearly the last point that the first stage ended. In site gelled acid stage volume should not exceed 0.5 PV. No benefits were gained by increasing the volume of in situ gelled acids. Retention of total iron in the core increased in multistage acid treatments, especially at low acid injection rates.

Use of the Finite Element Method in the Analysis of Impact-Induced Longitudinal Waves in Constrained Elastic Systems

1995 ◽  
Vol 117 (2A) ◽  
pp. 336-342 ◽  
Author(s):  
W. H. Gau ◽  
A. A. Shabana
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Virtual Work ◽  
Fourier Method ◽  
Jump Discontinuity ◽  
Elastic Rods ◽  
The Finite Element Method ◽  
Longitudinal Waves ◽  
The Impact ◽  
Element Method

In rotating elastic rods, dispersions occurs as the result of the finite rotations. By using Fourier method, it can be shown that the impact-induced longitudinal waves no longer travel with the same phase velocities. Furthermore, the speeds of the wave propagation are independent of the impact conditions including the value of the coefficient of restitution. In this investigation the use of the finite element method in the analysis of impact-induced longitudinal waves in rotating elastic rods is examined. The equations of motion are developed using the principle of virtual work in dynamics. Jump discontinuity in the system velocity vector as result of impact is predicted using the generalized impulse momentum equations. The solution obtained using the finite element method is compared with the solution obtained using Fourier method. Numerical results show that there is a good agreement between the solution obtained by using Fourier method and the finite element solution in the analysis of wave motion. However, discrepancies between the two solutions in the analysis of the velocity waves are observed and discussed in this paper.

Stability of eccentric core–annular flow

1995 ◽  
Vol 282 ◽  
pp. 233-245 ◽  
Author(s):  
Adam Huang ◽  
Daniel D. Joseph
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
The Finite Element Method ◽  
Two Phase ◽  
Two Fluids ◽  
The Core ◽  
Steady Solutions ◽  
Fluid Dynamics Equations ◽  
Concentric Flow ◽  
Element Method

Perfect core-annular flows are two-phase flows, for example of oil and water, with the oil in a perfectly round core of constant radius and the water outside. Eccentric core flows can be perfect, but the centre of the core is displaced off the centre of the pipe. The flow is driven by a constant pressure gradient, and is unidirectional. This kind of flow configuration is a steady solution of the governing fluid dynamics equations in the cases when gravity is absent or the densities of the two fluids are matched. The position of the core is indeterminate so that there is a family of these eccentric core flow steady solutions. We study the linear stability of this family of flows using the finite element method to solve a group of PDEs. The large asymmetric eigenvalue problem generated by the finite element method is solved by an iterative Arnoldi's method. We find that there is no linear selection mechanism; eccentric flow is stable when concentric flow is stable. The interface shape of the most unstable mode changes from varicose to sinuous as the eccentricity increases from zero.

Impact Damage Analysis and Experimental Test of Carbon/Epoxy Composite Laminate

2015 ◽  
Vol 1120-1121 ◽  
pp. 590-592
Author(s):  
Hyoh Yun Choi ◽  
Yeon Jun Lim ◽  
Hyun Jun Cho ◽  
Hyun Bum Park
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Composite Laminate ◽  
Impact Analysis ◽  
Impact Damage ◽  
The Finite Element Method ◽  
Fem Model ◽  
The Impact ◽  
Method Analysis ◽  
Element Method

In this work, study on impact damage FEM model of composite structure was performed. From the finite element method analysis results of composite laminate, it was confirmed that the results of analysis was reasonable. The velocity of impactor to initiate damage was estimated, and in order to investigate the damage at the predicted velocity, impact analysis using finite element method was performed. According to the impact analysis results of composite laminate, it was confirmed that the damage was generated at the estimated impact velocity. Finally, the comparison of the numerical results with those measured by the experiment showed good agreement.

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