Comparison of Design by Analysis Methods

2006 ◽  
Author(s):  
Sebastian Schindler
Keyword(s):  
Cross Section ◽  
Rectangular Cross Section ◽  
Pressure Vessels ◽  
Element Analysis ◽  
Advantages And Disadvantages ◽  
Direct Route ◽  
Analysis Methods ◽  
Air Cooler ◽  
Section Viii ◽  
Division 2

The paper discusses the advantages and disadvantages of the two well known Design by Analysis methods for unfired pressure vessels: the stress categorisation method (as given e.g. in the 2004 ASME B&BV Code Section VIII Division 2 [1], and EN 13445-3 Annex C [2]) and the new Direct Route (using elastic-plastic finite-element analysis) as given in EN 13445-3 Annex B [2]. A comparison of results is given for examples of various degree of difficulty to show the principal ideas and the applicability of the two approaches: a dished end with a nozzle in the knuckle region, a cylindrical shell to flat end connection and a rather complex header of an air cooler with rectangular cross section. As shown by the considered examples, the Direct Route method gives unique solutions (which is not always the case for stress categorisation) and can be advantageous in some cases, but requires a more time consuming analysis. The questionable design limits given by the 3f-criterion of the stress categorisation method can be avoided by usage of the progressive plastic deformation design check of the Direct Route if the required number of action cycles is low.

General Criteria and Evaluations for the Selection of ASME Section VIII, Division 1 or 2 for New Construction Pressure Vessels

2020 ◽  
Author(s):  
Nathan Barkley ◽  
Matt Riley
Keyword(s):  
Pressure Vessels ◽  
Design Rules ◽  
Advantages And Disadvantages ◽  
Division 1 ◽  
New Construction ◽  
Section Viii ◽  
Division 2 ◽  
Design Pressure ◽  
Selection Of

Abstract For new ASME pressure vessel designs that have a design pressure less than 10,000 psi (70 MPa), it is commonly questioned whether Section VIII, Division 1 or Division 2 should be used as the code of construction. Each code offers specific advantages and disadvantages depending on the specific vessel considered. Further complicating the various considerations is the new Mandatory Appendix 46 of Division 1 which allows the design rules of Division 2 to be used for Division 1 designs. With the various options available, determining the best approach can be challenging and is often more complex than only determining which code provides the thinnest wall thickness. This paper attempts to address many of the typical considerations that determine the use of Division 1 or Division 2 as the code of construction. Items to be considered may include administrative burden, certification process, design margins, design rules, and examination and testing requirements. From the considerations presented, specific comparisons are made between the two divisions with notable differences highlighted. Finally, sample evaluations are presented to illustrate the differences between each code of construction for identical design conditions. Also, material and labor estimates are compiled for each case study to provide a realistic comparison of the expected differential cost between the construction codes.

scholarly journals Finite Element Analysis of Gasket in Pressure Vessel

2021 ◽  
Vol 9 (11) ◽  
pp. 1390-1393
Author(s):  
Sanjana Jaishankara
Keyword(s):  
Pressure Vessel ◽  
Design Procedure ◽  
Pressure Vessels ◽  
Project Work ◽  
Element Analysis ◽  
Applied Loading ◽  
Sealing Performance ◽  
Riveted Joints ◽  
Section Viii ◽  
Division 2

Abstract: Pressure vessel is a closed container designed to hold liquids or gases at a pressure which are higher than the surrounding atmospheric pressure. These pressure vessels are not made as a single component but manufacture with an assembly of many other components and connected through bolted joints or riveted joints or welded joints. These joints are susceptible to failure and cause leakage of the liquid or gas which are very dangerous and sometimes causes heavy loss of life, health and property. Hence proper care has to be taken during the design analysis processes by following ASME section VIII division 1 which specifies the design-by-formula approach while division 2 contains a set of alternative rules based on design by Analysis (FEA) to determine the expected deformation and stresses that may develop during operation. The ASME section-VIII division-2 standards are used for the design of pressure vessel. Leakage in gasketed flanged joints have always been a great problem for the process industry. The sealing performance of a gasketed flanged joints depends on its installation and applied loading conditions. The present project work involves the design procedure and stress analysis (Structural Analysis) for the leak proof pressure vessel at the gasket under three different gasket conditions. Keywords: 1. FEM, 2. ASME, 3. ANSYS, 4. Gasket,5. Displacement,6. Stress

Development of Design Rules for Nozzles in Pressure Vessels for the ASME B&PV Code, Section VIII, Division 2

2011 ◽  
Author(s):  
Zhenning Cao ◽  
Les Bildy ◽  
David A. Osage ◽  
J. C. Sowinski
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Working Pressure ◽  
Element Analysis ◽  
Design Rules ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

The theory behind the pressure-area method that is incorporated in the ASME B&PV Code, Section VIII-2 is presented in this paper. Background and insight to the nozzle rules of ASME B&PV Code, Section VIII, Division 2, Part 4, paragraph 4.5 are also provided. Recommendations for modifying the current nozzles rules, those published in ASME B&PV Code, Section VIII, Division 2, 2010 Edition, is given based on continuing research and development efforts. A comparison between experimental results, results derived from detailed finite element analysis (FEA), the rules prior to the VIII-2 Rewrite (2004 Edition), and the rules in VIII-2 are provided in terms of a design margin and permissible maximum allowable working pressure (MAWP) computed with the design rules. A complete description of the theory including a commentary and comparison to experimental results is provided in WRC529 [1].

Vessel Design for Unintended Detonation: A Comparison of Alternative Code Rules

2016 ◽  
Author(s):  
David J. Gross ◽  
Thomas C. Ligon ◽  
John C. Minichiello
Keyword(s):  
Treatment Process ◽  
Waste Treatment ◽  
High Stress ◽  
Pressure Vessels ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Process Waste ◽  
Section Viii ◽  
Alternative Code ◽  
Division 2

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) will process waste slurries that have the potential to generate flammable gases and will utilize a number of atmospheric vessels to store these slurries at various stages of the waste treatment process. Throughout the design process, provisions have been made to ensure that these flammable gasses are vented from these vessels and to eliminate potential sources of ignition. However, Bechtel National, Inc. (BNI) would like to be able to demonstrate that these vessels are capable of withstanding a limited number of unintended detonations. It is well known that pressure vessels may be designed for internal detonations. However, these loadings tend to cause very brief transients of high stress that can make traditional stress-based design rules to be difficult to meet. In the past decade, a number of strain-based design methodologies have become available, including ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Part 5; ASME Section VIII, Division 3; ASME Section VIII, Division 3 Code Case 2564; and API 579-1 / ASME FFS-1. Each of these sets of rules permits some degree of plasticity in vessel design, but there are key differences in the specific provisions. In this paper, the use of these different sets of Code rules will be demonstrated in the context of the design of a WTP vessel for a single unintended detonation, and the advantages and disadvantages of these alternative design approaches will be discussed.

scholarly journals COMPARATIVE ANALYSIS OF CONSTRUCTION TECHNOLOGIES FOR THE DEVELOPMENT OF UNDERGROUND PARKING SPACE: THE EXAMPLE OF MOSCOW

2021 ◽  
Vol 78 (1) ◽  
pp. 102-110
Author(s):  
Anishchenko ◽  
V.L. Belyaev
Keyword(s):  
Comparative Analysis ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Parking Space ◽  
Advantages And Disadvantages ◽  
The World ◽  
Trenchless Technologies

The article reveals the advantages and disadvantages of various technologies for the mechanized construction of underground parking, which are used in the leading capitals of the world and offers an analysis of the effectiveness of these technologies for the conditions of Moscow. Among the most commonly used trenchless technologies, parking is considered in mines arranged by mechanized shaft-boring complexes, the construction of support by the method of a screen of pipes and the construction of parking by the method of jackpunching pipes of rectangular cross-section.

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

An Empirically Determined Design Guideline for Rectangular Cross Section Nitinol Flexure Hinges With the Focus on Flexibility-Strength Trade-Off

2018 ◽  
Author(s):  
S. Coemert ◽  
M. Olmeda ◽  
J. Fuckner ◽  
C. Rehekampff ◽  
S. V. Brecht ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Cross Section ◽  
Electrical Discharge Machining ◽  
Rectangular Cross Section ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Design Guideline ◽  
Trade Off ◽  
Flexure Hinges ◽  
Compliance Modeling

In our group, we are developing flexure hinge based manipulators made of nitinol for minimally invasive surgery. On the one hand, sufficient flexibility is required from flexure hinges to be able to cover the surgical workspace. On the other hand, the bending amount of the flexure hinges has to be limited below the yielding point to ensure a safe operation. As a result of these considerations, it has to be questioned how much bending angle a nitinol flexure hinge with given geometric dimensions can provide without being subject to plastic deformation. Due to the nonlinearities resulting from large deflections and the material itself, the applicability of the suggested approaches in the literature regarding compliance modeling of flexure hinges is doubtful. Therefore, a series of experiments was conducted in order to characterize the rectangular cross section nitinol flexure hinges regarding the flexibility-strength trade-off. The nitinol flexure hinge samples were fabricated by wire electrical discharge machining in varying thicknesses while keeping the length constant and in varying lengths while keeping the thickness constant. The samples were loaded and unloaded incrementally until deflections beyond visible plastic deformation occured. Each pose in loaded and unloaded states was recorded by means of a digital microscope. The deflection angles yielding to permanent set values corresponding to 0.1% strain were measured and considered as elastic limit. A quasilinear correlation between maximum elastic deflection angle and length-to-thickness ratio was identified. Based on this correlation, a minimal model was determined to be a limit for a secure design. The proposed guideline was verified by additional measurements with additional samples of random dimensions and finite element analysis.

Beyond Shakedown-Ratcheting Boundary

2018 ◽  
Author(s):  
R. Adibi-Asl ◽  
W. Reinhardt
Keyword(s):  
Cyclic Loading ◽  
Plastic Strain ◽  
Fatigue Damage ◽  
Thermal Load ◽  
Pressure Vessels ◽  
Growth Strain ◽  
Strain Condition ◽  
Element Analysis ◽  
Permanent Strain ◽  
Section Viii

The ASME Boiler and Pressure Vessel Code (Section III and Section VIII) provides requirements to avoid a ratcheting (accumulating permanent strain) condition under cyclic thermal load application. The ratchet check in this code is based on the solutions presented by Miller in 1959. One important focus in Miller’s work was to estimate the accumulated plastic strain under cyclic loading. The existing pressure vessels and piping codes have been adopting Miller’s ratchet boundary solution where there is no cyclic plastic accumulation of strain. However, some of these codes also provide limit on accumulated plastic strain under ratcheting conditions. Since the cyclic loading also causes fatigue damage in thee component, the question how to account for the interaction of ratchet deformation, which may contribute to damage in the material, and fatigue damage arises, since the fatigue curves are obtained from tests in the absence of ratcheting. This paper investigates the solutions to calculate growth strain (incremental plastic strain) and their application in design including taking into account the interaction with fatigue. Finite element analysis is presented to validate the analytical solutions.

scholarly journals An Ability to Adapt and Change

2014 ◽  
Vol 136 (11) ◽  
pp. 36-37
Author(s):  
Madiha El Mehelmy Kotb
Keyword(s):  
Life Cycle ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Electronic Format ◽  
The World ◽  
Regulatory Approach ◽  
Section Viii ◽  
Division 2 ◽  
Service Inspection ◽  
Technical Services

This article reviews about the views of Madiha El Mehelmy Hotb, the Head of the Pressure Vessels Technical Services Division for Regie Du Batiment Du Quedec, on how ASME Boiler and Pressure Vessel Code has evolved over the years. Hotb reveals that during the 1980s, ASME’s regulatory approach covered all aspects of the life cycle of a boiler or a pressure vessel from design to being taken out of service. It also confirmed every step in between – fabrication, installation, repair and modification, and in-service inspection. During later years, the institution moved toward accreditation of authorized inspection agencies, changed the publication cycle from three years to two, eliminated addenda, and restructured the Code committees. New Section VIII and division 2 were written, and the Codes were published in digital electronic format. Hotb believes that the Code will continue to be widely used and adopted in future. It will have a bigger and larger input from all over the world and will have further outreach and adoption by far more countries.

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