METHODOLOGY FOR CALCULATING THE STRESS STATE OF THE PILLAR FOR THE SALVAGE CHAMBER IN THE PRESENCE OF AN ADJACENT MINED OUT LONGWALL

2021 ◽  
Vol 4 (1) ◽  
pp. 364-374
Author(s):  
I. A. Ermakova ◽  
◽  
V. A. Fedusov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Quantitative Assessment ◽  
Underground Mines ◽  
The Finite Element Method ◽  
Load Factors ◽  
Relevant Task ◽  
Mining Conditions ◽  
Edge Part

Analysis of salvage operations at the underground mines of JSC SUEK-Kuzbass has shown that they can have different locations relative to the previously mined out adjacent longwall, which has a significant impact on the duration of salvage operations. If there is a previously mined out adjacent longwall next to the salvage chamber, the duration of salvage operations increases significantly, in contrast to the case when the salvage chamber is located within a pillar, outside the zone affected by the previously mined out longwall. In this regard, the calculation of the stress state of the pillar for the salvage chamber in the presence of an ad-jacent previously mined out longwall is a relevant task. The paper presents a methodology for quantitative assessment of the stress affecting the pillar for the salvage chamber, based on the use of the finite element method. An example of calculating the stress on the pillar for the sal-vage chamber in the presence of an adjacent mined out longwall for specific geological and mining conditions is considered. It has been established that the presence of a previously mined out adjacent longwall causes additional load on the specified pillar. The highest load factors are observed in the edge part of the pillar near the ventilation gateroad.

scholarly journals УЗАГАЛЬНЕННЯ МОДЕЛІ ФОЛЬКЕРСЕНА НА ВИПАДОК ОСЬОВОЇ СИМЕТРІЇ

2021 ◽  
pp. 78-89
Author(s):  
К. П. Барахов
Keyword(s):  
Mathematical Model ◽  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Boundary Conditions ◽  
Classical Model ◽  
The Finite Element Method ◽  
Premature Failure ◽  
One Dimensional ◽  
Element Method

Thin-walled structures may contain defects as cracks and holes that are leftovers of the material the construction, is made of or they occur during the operation as a result of, for example, mechanical damage. The presence of holes in the plate causes a concentration of stresses at the boundary of the holes and ultimately leads to premature failure of the structural element. Repair of local damage of modern aircraft structures can be made by creating overlays that are glued to the main structure. The overlay takes on part of the load, unloading the damaged area. This method of repair provides tightness and aerodynamic efficiency to the structure. The calculation of the stress state of such glued structures is usually performed by using the finite element method. The classic models of the stress state of overlapped joints are one-dimensional. That is, the change of the stress state along only one coordinate is considered. At the same time, the connections of a rectangular form are also considered. The purpose of this work is to create a mathematical model of the stress state of circular axisymmetric adhesive joints and to build an appropriate analytical solution to the problem. It is assumed that the bending of the plates is absent; the deformation of the plates is even by thickness. The adhesive layer works only on the shift. The main plate and the overlay are considered isotropic. The solution is built on polar coordinates. The stress state of the connection depends only on the radial coordinate, i.e. one-dimensional. The solution is obtained in analytical form. This mathematical model is a generalization of the classical model of the adhesive connection of Volkersen to a circular or annular region and is considered for the first time. Boundary conditions are met exactly. The satisfaction of marginal conditions, as well as boundary conditions, leads to a system of linear equations with respect to the unknown coefficients of the obtained solutions. The model problem is solved and the numerical results are compared with the results of calculations performed by using the finite element method. It is shown that the proposed model has sufficient accuracy for engineering problems and can be used to solve problems of the design of aerospace structures.

Interference Fit Stress Concentrations with Full Chamfered Hub

2013 ◽  
Vol 572 ◽  
pp. 209-212 ◽  
Author(s):  
Juan Carlos Pérez-Cerdán ◽  
Miguel Lorenzo ◽  
Carmen Blanco
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Quantitative Determination ◽  
Numerical Simulations ◽  
Not Given ◽  
The Finite Element Method ◽  
Stress Concentrations ◽  
Interference Fit

Quantitative determination of stress concentrations factors (SCF) in interference fits joints is highly relevant since they are not given by the theory of pressure cylinders commonly used for designing them. We study the capability of using a full chamfered hub as a geometrical design for reducing SCF. Stresses distributions and stresses concentrations factors are analyzed as a function of parameters that define the hub geometry with the aim of optimizing the design of proposed modified hubs. To achieve this goal, diverse numerical simulations by means of the finite element method (FEM) were carried out in order to quantitatively estimate the stress state existing at hub-shaft interface.

scholarly journals The Action Result of the Concentrated Load on the Briquettes which Obtained from the Technogenous Material

2017 ◽  
Vol 2 (2) ◽  
pp. 97
Author(s):  
Yu.N. Loginov ◽  
N.А. Babailov ◽  
D.N. Pervukhina
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
The Finite Element Method ◽  
Concentrated Load ◽  
Tensile Stresses ◽  
Calculation Results ◽  
Element Method

<p class="TTPAbstract">In this study, the calculation results of the briquette stress state by the Finite element method are presented. The fields of compressive and tensile stresses in briquette are determined. The conditions affecting the process of the briquette destruction are considered.</p>

Analysis the Cable Replacement Method of Tianjin Yonghe Bridge

2011 ◽  
Vol 71-78 ◽  
pp. 1383-1387 ◽  
Author(s):  
Wen Juan Yao ◽  
Wu Yang ◽  
Xiao Yu Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Main Beam ◽  
The Finite Element Method ◽  
Replacement Method ◽  
Replacement Process ◽  
Before And After ◽  
Element Method

Taking Tianjin Yonghe bridge for example, the finite element method is adopted to simulate each stages of cable replacement process, the dates of tension, the alignment of main beam and the change of stress before and after cable replacement are compared and analysed, The measured value is greatly consistent with calculated value, Stress state of the bridge has been greatly improved, the weight of main beam bearing by the cable will be shared by a few closed cable after unloading, so the cables which are more serious corroded should be replaced.

Analysis of Influence of Raft Stiffness on Tall Building Interaction System

2012 ◽  
Vol 166-169 ◽  
pp. 1007-1013
Author(s):  
Xiu Zhu Sun ◽  
Liao Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Interaction Design ◽  
Design Method ◽  
Tall Building ◽  
The Finite Element Method ◽  
Interaction System ◽  
Practical Design ◽  
Stress And Deformation

The raft foundation has been widely applied to tall building, in consideration of the stress state is complex and the stress mechanism is unclear, there are many unreasonable problems while determined the raft thickness at this stage. This paper used the finite element method and the interaction design method, on the basis of analysis of stress and deformation under the condition of different raft thickness, get the raft stress and deformation principle, provides a reference experiences to practical design.

scholarly journals Deformating of a viscoelastic disk rotating with acceleration

2020 ◽  
pp. 143-151
Author(s):  
Александра Сергеевна Бегун ◽  
Лариса Валентиновна Ковтанюк
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress State ◽  
Finite Difference Method ◽  
Axisymmetric Problem ◽  
Plane Stress State ◽  
Constant Thickness ◽  
The Finite Element Method ◽  
Hard Inclusion ◽  
The Finite Difference Method

Рассматривается деформирование вязкоупругого диска, вращающегося с изменяющейся скоростью (разгон, торможение и вращение с постоянной скоростью). Для математического моделирования процесса деформирования используется теория течения. При предположении плоского напряженного состояния получена система дифференциальных уравнений для определения полей напряжений, обратимых и необратимых деформаций и перемещений. Численное решение этой системы уравнений найдено с помощью конечно-разностного метода. В случае решения осесимметричной задачи используется метод конечных элементов, реализованный в пакете Freefem++. Рассмотрено деформирование полого диска и диска с жестким включением, как постоянной толщины, так и переменной. The deformation of a viscoelastic disk rotating with a changing speed is considered. Within the framework of the theory of flow, relations are obtained that allow one to calculate the fields of stresses, strains, displacements, and velocities. To solve these equations in the case of a plane stress state, the finite-difference method is used, in the case of an axisymmetric problem, the finite element method implemented in the Freefem ++ package is used. Acceleration, braking and rotation at a constant speed are considered. The deformation of a hollow disk and a disk with a hard inclusion of both a constant thickness and a variable is considered.

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