scholarly journals Investigation of Alardinskaya mine coal bumps causes using computer simulation of rock massif stress conditionals

2021 ◽  
Vol 326 ◽  
pp. 00008
Author(s):  
Andrey Sidorenko ◽  
Vyacheslav Alekseev ◽  
Yury Sirenko

The purpose of the paper was to identify the causes of rock bumps that occurred at the Alardinskaya mine (Russia) in 2011. The research was carried out using the finite element method. The developed three-dimensional model of the rock mass included a coal seam, rocks bedding above and below, goaf, and a system of local preparatory workings. The situation that arose immediately before the first rock burst was modeled during the research - when the longwall crossed a diagonal entry. The performed investigations enabled the authors to make a conclusion about a high danger of using technological schemes for the development of seams by longwalls leaving pillars that have a width less than the length of the support pressure zone, especially due to diagonal entries. As a safe technology for the longwall development of seams prone to rock bursts, it is recommended to apply a technological scheme with the abandonment of wide barrier pillars and four preparatory workings in each section, which has proven itself in the processing of rock bump hazardous seams in the state of Utah (USA).

Author(s):  
Ján DIŽO ◽  
Miroslav BLATNICKÝ ◽  
Paweł DROŹDZIEL ◽  
Stanislav SEMENOV ◽  
Evgeny MIKHAILOV ◽  
...  

The lorry frame is the main carrying part of a lorry, composed of several components. These components are connected by joints into one structural unit and it forms the lorry chassis. The contribution of this article is focused on the strength analyses of a backbone frame, which is used on an off-road lorry chassis. Strength analyses are carried out utilising the finite element method. This article presents a created three-dimensional model of the frame and definition of boundary conditions (loads, the definition of degrees of freedom) needed for simulation computations. Results of the numerical calculations are the main parts of this article. Attention is mainly centred on the distribution of stresses of the frame under defined loads and its deformations.


Vestnik IGEU ◽  
2019 ◽  
pp. 12-23
Author(s):  
V.A. Gorbunov ◽  
N.A. Lonshakov ◽  
I.V. Alekseyev ◽  
M.N. Mechtayeva

A problem to be solved now is determining the hub nodes of hydraulic losses arising during the operation of power plant equipment. Detection of such points directly by measuring devices on the operating equipment is impossible as it is difficult to access many elements of the flow part of the units. Development of digital models of equipment allows simulating these processes and with a high degree of accuracy determining the location of increased hydraulic losses. The aim of this work is to determine the magnitude and localization of hydraulic losses in the control valve of the steam turbine. The analysis of steam turbine valve operation has been carried out based on thermodynamic, hydraulic and mechanical parameters, which are taken directly during the operation of the power plant by standard control and measuring devices. The obtained information was processed by the finite element method in the Ansys and SolidEdge Flow Simulation programs and by three-dimensional modeling in the SolidEdge software package. We have obtained a three-dimensional model of the control valve and determined the fields of pressure, velocity, etc. distribution in the volume of the control valve under different operating conditions by the finite element method. During the processing of the obtained information, we found excessive energy losses of water vapor arising during its throttling in the control valve. Such losses produce a significant effect on the power developed by the turbine pump. During the operation of the drive turbine, the pressure losses of the working medium in the steam distribution system vary in the range of 300–500 kPa (37–62 % of the initial pressure before the control valve). The goal set in the work has been fully achieved. Verification of the developed three-dimensional model was made on the basis of the operational parameters taken during the steam turbine operation. The application of the work results, both for modernizing the existing units and designing new equipment, will increase the efficiency of electric energy production at the power unit of the station.


2011 ◽  
Vol 418-420 ◽  
pp. 884-887 ◽  
Author(s):  
Xiao Xiao Huang ◽  
Wen Dong Xue ◽  
Jie Liu ◽  
Fa Han

The three-dimensional model of purging plug was analyzed by the finite element method. The influence of slit structure (length, width, center radius and numbers) on the maximum principal stress was Contrastive studied in argon blowing process under the same boundary conditions.


Author(s):  
Patrick D. Lea ◽  
Charbel Farhat ◽  
Kevin G. Wang

This work extends and generalizes a recently developed fluid-structure coupled computational framework to model and simulate fluid-induced failure and fracture. In particular, a novel surface representation approach is proposed to represent a fractured fluid-structure interface in the context of embedded boundary method. This approach is generic in the sense that it is applicable to many different computational fracture models and methods, including the element deletion (ED) technique and the extended finite element method (XFEM). Two three-dimensional model problems are presented to demonstrate the salient features of the computational framework, and to compare the performance of ED and XFEM in the context of fluid-induced failure and fracture.


2015 ◽  
Vol 1125 ◽  
pp. 432-436 ◽  
Author(s):  
Sandro Mihradi ◽  
Calvindoro Zeus Abdiwijaya ◽  
Tatacipta Dirgantara ◽  
Andi Isra Mahyuddin

In the present research, three-dimensional models of above-knee prosthesis, consist of socket, four-bar linkage knee, pylon and foot, are developed. These models have to fulfill criteria such as stability, ability to withstand up to 90 kg of bodyweight, ability to flex up to 130 degree, easy for maintenance, simple manufacturing process, affordable and yet reliable. As the first step of development, these models were evaluated using finite element method software to determine whether or not the design has fulfilled strength criteria. The results show that the last iteration of the three dimensional model of the knee prosthesis has satisfied the criteria.


2006 ◽  
Vol 526 ◽  
pp. 193-198 ◽  
Author(s):  
Rodrigo Luri ◽  
C.J. Luis-Pérez

In this work, the strain field attained by using a severe plastic deformation (SPD) process called equal channel angular extrusion (ECAE) is studied by the finite element method (FEM). The three-dimensional model with circular section includes shear friction between the part and the die, the material strain hardening behaviour and a rigid-deformable contact between the billet and the die. In the ECAE process the part is extruded through two channels with similar diameter that intersect at an angle. When the extrusion process has been performed, the processed material remains it cross section, so there is not any geometric limitation to achieve the desired plastic strain. There are different ways of processing the material by using the ECAE process; those ways of processing are called routes. In this work two passages of route C have been simulated. Using route C means that the billet has been rotated 180º between each passage. Deformations imparted to the processed material have been calculated and a comparison with experimental results has been carried out.


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