On the Determination of the Influence of an Axial Preload Owing to Bolting on a Cylindrical Pressure Vessel

1961 ◽  
Vol 83 (2) ◽  
pp. 215-218
Author(s):  
P. R. Paslay
Keyword(s):  
Numerical Integration ◽  
Plastic Flow ◽  
Pressure Vessel ◽  
Elastic Solution ◽  
Cylindrical Pressure Vessel

An idealization of a cylindrical pressure vessel with end plates fastened by longitudinal bolts is considered. The initial axial preload is restricted to be below the load necessary to begin plastic flow and the bolting is assumed elastic throughout the application of pressure. The elastic solution is obtained and the plastic solution may be found by a numerical integration. An illustrative problem is included.

Strength of Thick-Walled Pressure Vessels for Materials With Directional Properties

1962 ◽  
Vol 84 (2) ◽  
pp. 197-202
Author(s):  
A. E. Dapprich ◽  
Joseph Marin ◽  
Tu-Lung Weng
Keyword(s):  
Tensile Stress ◽  
Pressure Vessel ◽  
Anisotropic Material ◽  
Pressure Vessels ◽  
Maximum Pressure ◽  
Closed Solution ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Cylindrical Pressure Vessel

This paper develops a theory for the determination of the plastic pressure-deformation relation in a thick-walled cylindrical pressure vessel subjected to internal pressure and made of an anisotropic material. In this theory, large or finite strains are considered and a closed solution is found for the pressure-strain relation based on a modified log-log tensile stress-strain relation. Theory is also developed for predicting the maximum pressure which the vessel can withstand.

MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 13. DETERMINATION OF DEFORMED STATE UNDER STRAITENED EXTRUSION IN FOURTH CENTRAL AREA OF PLASTIC DEFORMATION

2020 ◽  
Vol 0 (4) ◽  
pp. 43-51
Author(s):  
A. L. Vorontsov ◽  
◽  
I. A. Nikiforov ◽  
Keyword(s):  
Plastic Deformation ◽  
Plastic Flow ◽  
Central Area ◽  
Direct Extrusion ◽  
Deformed State ◽  
Cumulative Deformation ◽  
The Given ◽  
General Method

Formulae have been obtained that are necessary to calculate cumulative deformation in the process of straitened extrusion in the central area closed to the working end of the counterpunch. The general method of plastic flow proposed by A. L. Vorontsov was used. The obtained formulae allow one to determine the deformed state of a billet in any point of the given area. The formulae should be used to take into account the strengthening of the extruded material.

Research of stamping of unequal channel bars. Part 3. Force parameters and shape change of the billet when extruding channels. 2. Determination of the extrusion force, maximum pressure on the matrix wall and the heights of the walls, taking into account the elastic deformation jf the matrix

2021 ◽  
pp. 63-69
Author(s):  
A.L. Vorontsov
Keyword(s):  
Plastic Flow ◽  
Elastic Deformation ◽  
Shape Change ◽  
Plane Deformation ◽  
Maximum Pressure ◽  
Extrusion Force ◽  
System Of Equations ◽  
The Matrix ◽  
Theory Of Plastic Flow

On the basis of the system of equations of the theory of plastic flow, the forces, the maximum pressure on the wall of the matrix and the heights of the obtained walls when extruding channels are determined, taking into account the elastic deformation of the matrix. Keywords: die forging, extrusion, misalignment, punch, matrix, plane deformation, stresses. [email protected]

scholarly journals Methods for Structural Stress Determination according to EN 13445-3 Annex NA – Comparison with other Codes for Unfired Pressure Vessels

2018 ◽  
Vol 165 ◽  
pp. 10003
Author(s):  
Ralf Trieglaff ◽  
Jürgen Rudolph ◽  
Martin Beckert ◽  
Daniel Friers
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Structural Stress ◽  
Stress Determination ◽  
User Friendliness ◽  
Fatigue Assessment ◽  
Shell Elements ◽  
European Working ◽  
The Status

The European Pressure Vessel Standard EN 13445 provides in its part 3 (Design) a simplified method (Clause 17) and a detailed method for fatigue assessment (Clause 18). Clause 18 “Detailed Assessment of Fatigue Life” is under revision within the framework of the European working group CEN/TC 54/WG 53 – Design methods with the aim of reaching a significant increase in user-friendliness and a clear guideline for the application. This paper is focused on the new informative annex NA ”Instructions for structural stress oriented finite elements analyses using brick and shell elements”. As an essential amendment for the practical user, the determination of structural stress ranges for fatigue assessment of welds is further specified in this new annex. Different application methods for the determination of structural stresses are explained in connection with the requirements for finite element models and analyses. This paper will give a short overview of the proposed approaches of structural stress determination in annex NA of the revised EN 13445-3. It will present the status of the approaches based on the results of fatigue analyses according to EN 13445-3 Clause 18 for different application examples. For verification purposes, the results of the approaches proposed in EN 13445-3 are compared with the results of other pressure vessel design codes for nuclear and non-nuclear application.

scholarly journals Design and Fabrication of a Modified Portable Biogas Digester for Renewable Cooking-Gas Production

2018 ◽  
Vol 3 (3) ◽  
pp. 21
Author(s):  
Barinyima Nkoi ◽  
Barinadaa Thaddeus Lebele-Alawa ◽  
Benedict Odobeatu
Keyword(s):  
Pressure Vessel ◽  
Storage Tank ◽  
Raw Materials ◽  
Gas Production ◽  
Smoke Detector ◽  
Cow Dung ◽  
Nickel Steel ◽  
Cylindrical Pressure Vessel ◽  
Test Pressure ◽  
Materials Used

This research paper focuses on re-engineering design and fabrication of a modified potable biogas digester for the production of biogas as a renewable energy source for domestic use. Digesters used around the world are commonly big in size. There is need to modify and re-engineer an existing biogas digester to fit in to modern day design for better efficiency, portability and safety. Floating drum and Flexible balloon are digesters to be modified as a thin walled pressure vessel with radius-thickness ratio  greater than 10. ASME codes and standards were used to carry out the sizing calculations, thickness and pressure calculations for the cylindrical pressure vessel shells and also calculations for the storage tank hemisphere shell. AISI 304 (Chromium-Nickel steel) is used for the vessel shell and the maximum allowable stress is 137 MPa. Weld efficiency (85%), corrosion allowance (0.02mm),  of 24 (for digester),  of 18 (for collector) and  of 20 (storage tank). 17 kg of cow dung and 34 kg of water with temperature of 32oC were the raw materials used for this research to produce a cumulative gas volume of 0.1243 m3 for 30 days. Furthermore, a bike pump is modified and used to increase methane gas pressure from 4.903 kPa to 345 kPa to suit the modern day gas cookers design and storage tank. Unlike other biogas plant, an electronic smoke alarm detector (model: Ei100) is placed 300 mm below the digester top for effective fire protection. Series of tests were performed to ensure that the constructed prototype met the specifications/standards. Such test include, smoke detector test, pressure testing, gas leak test, and a unit test run also confirmed that the aim of research was achieved.

Calcul des éléments dipolaires et quadrupolaires de la matrice de transition moléculaire dans Na2

1990 ◽  
Vol 68 (4-5) ◽  
pp. 365-368 ◽  
Author(s):  
K. Hussein ◽  
O. Babaky
Keyword(s):  
Numerical Integration ◽  
Electronic States ◽  
Transition Elements ◽  
Simple Method ◽  
Selection Rules ◽  
Variable Formula ◽  
Method Of Calculation ◽  
Analytical Integration ◽  
Fifth Order

In this paper, we study a calculation of the transition elements [Formula: see text] between electronic states of the diatomic molecules Na2. We show the necessary selection rules for the determination of these operators by a method of analytical integration on the variable [Formula: see text], combined with a numerical integration to fifth order. The values found by this simple method of calculation are very reasonable and show that the important transitions [Formula: see text], [Formula: see text]; and [Formula: see text] of the dimer Na2 are dipolar. [Traduit par la revue]

To Analyze the Effects of Geometric Misalignment in a Cylindrical Pressure Vessel

2012 ◽  
Vol 152-154 ◽  
pp. 964-969 ◽  
Author(s):  
Musharaf Abbas ◽  
Asif Israr ◽  
Atiq Ur Rehman
Keyword(s):  
Finite Element ◽  
Alloy Steel ◽  
Pressure Vessel ◽  
Structural Integrity ◽  
High Strength ◽  
Fe Analysis ◽  
Low Alloy Steel ◽  
Affected Area ◽  
Cylindrical Pressure Vessel ◽  
Geometrical Effects

This particular work consider a pressurized vessel typically made of high strength low alloy steel and containing the geometric misalignment at the cylinder-to-cylinder junction. This misalignment produce in the vessel’s structure is because of girth weld that is evident in most of the fabrication of such type of structures apart from other factors which is beyond the scope of this study. This study evaluates the geometrical effects of mismatch on the structural integrity of the pressure vessel and prediction of stresses at the affected area of the cylinder. Analytical and Finite Element (FE) approaches are employed to analyze the configuration. FE analysis is performed by the use of ANSYS on one quarter of the structure due to symmetry. FE results are also compared with the analytical results of different authors. In addition, maximum allowable mismatch is also determined and is a part of this study.

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