scholarly journals CONSIDERATIONS ON THE STRESSES CONCENTRATION FACTOR

2016 ◽  
Vol 18 (4) ◽  
Author(s):  
FRATILA MARCU
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Concentration Factor ◽  
Finite Dimension ◽  
Analytical Relationship ◽  
The Finite Element Method ◽  
Method Of Least Squares ◽  
Technical Literature ◽  
Method Of Calculation

The paper analyzes stresses in an area of tension-type with geometric discontinuity concentrator. The geometric discontinuity is a hole located in a thin plate of finite dimension. The stresses and their variations were determined using the finite element method (FEM). Stresses values obtained with FEM, were used as basic data on the method of least squares to determine an analytical relationship, for calculating the coefficient of stress concentration. Relationship obtained by this method of calculation is compared with those in the technical literature.

Stress Concentration Factor Calculation for the Hooks in Lifting Appliance of Spent Fuel Well Cover

2014 ◽  
Author(s):  
Xiang Liu ◽  
Yue Li ◽  
Jinhua Wang ◽  
Bin Wu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Spent Nuclear Fuel ◽  
Curved Beam ◽  
Spent Fuel ◽  
The Finite Element Method ◽  
High Temperature Reactor

The spent nuclear fuel of HTR-PM (High Temperature Reactor–Pebblebed Modules) will be dry stored in wells. In the mouth of each well, there is a cover weighing 11 tons. A lifting appliance with three hooks is used to open and close the covers. The hooks are L-shaped with fillet at the inside corner. The stress concentration at the corner has a significant impact on the strength and fatigue life of hooks. For optimizing the structure of the hook, the stress concentration factor related to the radius of fillet is calculated by both theoretical and numerical methods. The theoretical calculation is based on the Saint-Venant’s Principle and the analytical solution of a curved beam. The result is consistent with the numerical calculation performed by the finite element method.

Improvements for a Hydraulic Excavator's Boom

2014 ◽  
Vol 490-491 ◽  
pp. 510-513
Author(s):  
Sheng Bin Wu ◽  
Xiao Bao Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
High Stress ◽  
The Finite Element Method ◽  
Element Method ◽  
Concentration Phenomenon

Focus on stress concentration and high stress area, four improvements were put forward through analyzed a hydraulic excavator's boom with the finite element method under the bucket digging condition. Compared the stress distribution graph, the results show that these schemes can improve the stress concentration phenomenon and the high stress distribution areas. The practices demonstrated the effectiveness to reduce the invalidation rate of hydraulic excavator's boom.

scholarly journals Vibrations of a deformed half-space with inclusion under the influence of surface waves

2021 ◽  
Vol 274 ◽  
pp. 03027
Author(s):  
Bakhodir Rakhmonov ◽  
Ismoil Safarov ◽  
Mukhsin Teshaev ◽  
Ravshan Nafasov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Surface Waves ◽  
Strain State ◽  
Maximum Stress ◽  
Harmonic Waves ◽  
The Finite Element Method ◽  
Seismic Impacts ◽  
Good Agreement

There is a large number of underground tunnels of various shapes located in seismic zones that need to be protected from seismic impacts. The paper considers the effect of harmonic surface waves on a cylindrical inclusion of various shapes located in a viscoelastic half-plane. The main purpose of the study is to determine the stress-strain state of the obstacle when exposed to harmonic waves. The problem is solved by the finite element method. It was found that the maximum stress concentration is allowed at long waves, and the stress concentration with increasing depth and wavelength approaches the static value of stress. The reliability of the obtained research results is confirmed by good agreement with theoretical and experimental results obtained by other authors.

scholarly journals Research of Maximum Stress Zones in Circular Plates with Loades Concentrated Force

2020 ◽  
Vol 70 (2) ◽  
pp. 77-90
Author(s):  
Konieczny Mateusz ◽  
Achtelik Henryk ◽  
Gasiak Grzegorz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Maximum Stress ◽  
Perforated Plate ◽  
Chemical Equipment ◽  
Circular Plates ◽  
The Finite Element Method ◽  
Concentrated Force ◽  
State Of Stress

AbstractThe paper presents numerical and experimental analysis of the state of stress in a circular perforated plate, free supported or fixed on entire premier and loaded concentrated force. This type of plate have found applications in the field of chemical equipment, pressure tanks and box conveyors. The use of the finite element method for numerical calculations enables accurate location of stress concentration zones in a perforated plate and allows to determine stress values around these hole.

Stress Concentration Factors of Cross-Bores in Thick Walled Cylinders and Blocks

2004 ◽  
Vol 126 (2) ◽  
pp. 184-187 ◽  
Author(s):  
Ricky D. Dixon ◽  
Daniel T. Peters ◽  
Jan G. M. Keltjens
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Cylindrical Shells ◽  
Ease Of Use ◽  
Stress Fields ◽  
The Finite Element Method ◽  
Internal Radius ◽  
Concentration Factors ◽  
Stress Concentration Factors

The purpose of this paper is to investigate the stress concentration in stress fields around crossbores for closed-end thick-walled square blocks and cylindrical shells using the finite element method. These stress concentration factors are presented and discussed as a function of the ratio of crossbore radius to the cylinder internal radius (HR/Ri=0.01 to 0.7) for a range of wall ratios (Y=1.5 to 5). Charts and simple expressions are provided for ease of use.

scholarly journals Determining the stress concentration change with time in a viscoelastic orthotropic solid

2020 ◽  
pp. 28-34
Author(s):  
M.F. Selivanov ◽  
◽  
Y.R. Kulbachnyy ◽  
D.R. Onishchenko ◽  
◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Stiffness Matrix ◽  
Orthotropic Material ◽  
Orthotropic Plate ◽  
Round Hole ◽  
The Finite Element Method ◽  
Time Step ◽  
Element Method

The procedure for solving the plane problem of the linear theory of viscoelasticity by the finite element method is described. Based on the virtual work principle and the assumption of the constancy of the strain rate at small intervals of time, the matrix form of the equilibrium equations of the finite-element approximation of a body is written. The solution procedure is described for the constitutive relations in the Boltzmann—Volterra integral form. This integral is transformed into an incremental form on a time mesh, at each interval of which the problem is solved by the finite element method with unknown increments of displacements. The numerical procedure is constructed by ununiformly dividing the time interval, at which the study is conducted. In this case, the stiffness matrix requires recalculation at each time step. The relaxation functions of the moduli of a viscoelastic orthotropic material are described in the form of the Proni—Dirichlet series. The solution to the problem of determining the change over time of the stress concentration in a body with a round hole in a viscoelastic orthotropic plate is presented. To construct a numerical solution, the three moduli of orthotropic material were written using one exponent with the same relaxation time. For these initial data, an analytic expression for the viscoelastic components of the stiffness matrix of an orthotropic plate under plain stress conditions is constructed. Numerical examples are presented for several ratios of the hole radius to the size of the plate. These results are compared with the solution obtained for an infinite plate by inverse transformation by a numerical method of the well-known analytic elastic solution.

Numerical Analysis of a Crack Emanating from Semicircular Notch with Connection to a Pre-Existing Crack

2012 ◽  
Vol 428 ◽  
pp. 114-120
Author(s):  
Mohamed Sahnoun ◽  
Djamel Ouinas
Keyword(s):  
Finite Element Method ◽  
Stress Intensity Factor ◽  
Finite Element ◽  
Stress Intensity ◽  
Numerical Analysis ◽  
Stress Concentration ◽  
Intensity Factor ◽  
Stress Field ◽  
The Finite Element Method ◽  
Stress Concentrations

The real structures are of complex geometrical forms containing numerous zones of stress concentrations. These sites are characterized by weak sections due to the presence of notches which are the main causes of cracks initiation. The knowledge of the distribution of the stress field in the neighborhood of a notch is of an extreme importance for the analysis of the variation of the stress concentration factor with respect to the geometry of the notch. In this paper, the finite element method is used to study the effect of the existence of a microcrack on the behaviour of a notched structure. Then the behaviour of a crack emanating from the notch with the presence of the pre-existing crack is also investigated. It requires estimating the stress intensity factor at the crack tip, the length of the crack, the notch diameter and the angle between its bisecting line and the crack direction.

Reduction of stress concentration around a hole in a uniaxially loaded plate

1983 ◽  
Vol 18 (2) ◽  
pp. 135-141 ◽  
Author(s):  
U C Jindal
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Concentration ◽  
Circular Hole ◽  
High Order ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Loaded Plate ◽  
Hole Geometry ◽  
Element Method

The stress concentration around a circular hole in a plate can be reduced by up to 21 per cent by introducing auxiliary holes on either side of the original hole. But this approach of auxiliary holes creates two more regions of stress concentration in the plate. In the present study, the hole geometry has been modified to effect stress reductions as high as 22 per cent. The problem has been analysed numerically by the finite element method and experimentally by two-dimensional photoelasticity. It has been observed that by making the hole oblong in the direction of loading, a high order of reduction in stress concentration around the hole can be obtained.

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