Determination of the stressed-strained state of nonthin transversally isotropic spherical shells with elastically stiffened curvilinear holes

1999 ◽  
Vol 35 (8) ◽  
pp. 767-777
Author(s):  
Yu. N. Nemish ◽  
I. Yu. Khoma ◽  
D. I. Chernopiskii
Keyword(s):  
Strained State ◽  
Spherical Shells ◽  
Transversally Isotropic ◽  
Curvilinear Holes

A Direct Experimental Determination of the Elastic Contribution of Chain Entangling in a Tightly Crosslinked Elastomer

1982 ◽  
Vol 55 (1) ◽  
pp. 62-65
Author(s):  
W. Batsberg ◽  
O. Kramer
Keyword(s):  
Stress Relaxation ◽  
Elastic Equilibrium ◽  
Relaxation Modulus ◽  
Chain Scission ◽  
Experimental Result ◽  
Strained State ◽  
Equilibrium Stress ◽  
Linear Chains ◽  
Network Methods

Abstract The experimental result, that the equilibrium force is nearly equal to the pseudoequilibrium force immediately prior to quenching and irradiation, allows the following conclusions: (1) Chain scission during crosslinking is not a serious problem. (2) The network of highly entangled linear chains is effectively at elastic equilibrium immediately prior to crosslinking in the strained state. This would not be the case if the entangled structure remained untrapped. (3) The effect of chain entangling in tightly crosslinked elastomers is large, also at elastic equilibrium. In fact, it is almost quantitatively equal to the pseudo-equilibrium stress relaxation modulus of the uncrosslinked linear polymer. This result is in agreement with the results from the Langley and the two-network methods.

scholarly journals Calculation of thin isotropic shells beyond the elastic limit by the method of elastic solutions

2018 ◽  
Vol 196 ◽  
pp. 01014 ◽  
Author(s):  
Avgustina Astakhova
Keyword(s):  
Elastic Limit ◽  
Physical Nonlinearity ◽  
Elasticity Tensor ◽  
Thin Shells ◽  
Equilibrium Equations ◽  
Spherical Shells ◽  
Plastic Deformations ◽  
Elastic Plastic ◽  
Internal Forces

The paper focuses on the model of calculation of thin isotropic shells beyond the elastic limit. The determination of the stress-strain state of thin shells is based on the small elastic-plastic deformations theory and the elastic solutions method. In the present work the building of the solution based on the equilibrium equations and geometric relations of linear theory of thin shells in curved coordinate system α and β, and the relations between deformations and forces based on the Hirchhoff-Lave hypothesis and the small elastic-plastic deformations theory are presented. Internal forces tensor is presented in the form of its expansion to the elasticity tensor and the additional terms tensor expressed the physical nonlinearity of the problem. The functions expressed the physical nonlinearity of the material are determined. The relations that allow to determine the range of elastic-plastic deformations on the surface of the present shell and their changing in shell thickness are presented. The examples of the calculation demonstrate the convergence of elastic-plastic deformations method and the range of elastic-plastic deformations in thickness in the spherical shell. Spherical shells with the angle of half-life regarding 90 degree vertical symmetry axis under the action of equally distributed ring loads are observed.

Determination of the strained state of thin-walled cellular structures

2009 ◽  
Vol 45 (4) ◽  
pp. 542-554 ◽  
Author(s):  
M. H. Stashchuk ◽  
M. I. Dorosh
Keyword(s):  
Cellular Structures ◽  
Strained State ◽  
Thin Walled

scholarly journals Investigation of а stress-strained state of a screw-shape tubes of heat exchangers

2020 ◽  
pp. 13-23
Author(s):  
Serhii Pyskunov ◽  
Serhii Trubachev ◽  
Oleksandr Baranyuk
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Strain State ◽  
Air Flow ◽  
Strained State ◽  
Test Task ◽  
Geometric Characteristics ◽  
Simulation Results ◽  
Brass Screw

Based on the results of the study of the parameters of the air flow inside of the brass screw-shape tube of the heat exchanger, the determination of their optimal geometric characteristics and further modeling of the stress-strain state was performed. Verification of simulation results is carried out on the basis of comparison with the test task.

scholarly journals Development of a Procedure for the Determination of the Buckling Resistance of Steel Spherical Shells According to EC 1993-1-6

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 25
Author(s):  
Paweł Błażejewski
Keyword(s):  
Spherical Shell ◽  
Simple Calculation ◽  
Difficult Problem ◽  
Calculation Algorithm ◽  
Spherical Shells ◽  
Engineering Approach ◽  
Low Degree ◽  
Buckling Resistance

This paper presents the process of developing a new procedure for estimating the buckling capacity of spherical shells. This procedure is based entirely on the assumptions included in the standard mentioned, EN-1993-1-6 and also becomes a complement of EDR5th by unifying provisions included in them. This procedure is characterized by clarity and its algorithm is characterized by a low degree of complexity. While developing the procedure, no attempt was made to change the main postulates accompanying the dimensions of the spherical shells. The result is a simple engineering approach to the difficult problem of determining the buckling capacity of a spherical shell. In spite of the simple calculation algorithm for estimating the buckling capacity of spherical shells, the results obtained reflect extremely accurately the behavior of real spherical shells, regardless of their geometry and the material used to manufacture them.

To the Question of the Metal Magnetic Memory Method Application for Stress-Strained State Determination of Metal Structures

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 43-46
Author(s):  
Шубочкин ◽  
Andrey Shubochkin ◽  
Ефимов ◽  
Aleksey Efimov ◽  
Горкунов ◽  
...  
Keyword(s):  
Statistical Data ◽  
Magnetic Memory ◽  
Strained State ◽  
Metal Magnetic Memory ◽  
Metal Structures ◽  
State Determination ◽  
Real Objects ◽  
Physical Limitations ◽  
Metal Magnetic Memory Method

The article considers the possibility of using the MMM method for stress-strained state determination of metal structures. The problems of MMM method physical limitations are discussed; statistical data obtained from the real objects monitoring are presented. It is concluded that it is impossible to give any opinion about the object’s state (i.e. the object has or has not defects) on the basis of the MMM method results without confirmation it by any other NDT method because just absence of magnetic anomalies does not indicate that the stress-strained state of the object is absent or low. It is shown that the "contactless magnetometric diagnostics", which uses surface signal registration from defects leakage fields and from the areas with weak local magnetic irregularities, cannot be applied for pipelines diagnostics.

scholarly journals Prediction of the Elastic Tensor of 3D Composites by an Analytical Model

1999 ◽  
Vol 8 (5) ◽  
pp. 096369359900800
Author(s):  
C. Tallaron ◽  
S. Barre
Keyword(s):  
Volume Fraction ◽  
Unidirectional Composite ◽  
Second Step ◽  
Relative Role ◽  
Elastic Tensor ◽  
The Matrix ◽  
Three Bundles ◽  
Transversally Isotropic

The aim of this study is the determination of the overall elastic tensor of two 3D composites. These materials have a multiscale architecture. The representative volume element of the composite architecture (symbolised by a unit-cell) is composed of three bundles in three orthogonal directions and two matrix pockets. Each bundle is a unidirectional composite formed by a juxtaposition of long fibres surrounded by the matrix. Due to their symmetry, the bundles are considered transversally isotropic according to the fibres axis, whereas the pockets are macroscopically isotropic. The analytical computation is produced in two steps. The first step consists of determining the elastic tensor of the bundles. The second step is the calculation of the elastic tensor of the whole composite. The most part of the used equations comes from bibliography, excepted the determination of shear coefficients of the composite. The last part of this study devoted to the influence of material parameters presents the relative role of the fibres, the matrix and their volume fraction.

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