Protection Against Local Failure for Impulsively Loaded Vessels

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Alan M. Clayton ◽  
Thomas A. Duffey
Keyword(s):  
Damage Mechanics ◽  
Local Strain ◽  
Pressure Vessels ◽  
Local Failure ◽  
Hoop Strain ◽  
Direct Extension ◽  
Asme Code ◽  
Section Viii ◽  
Shell Geometry ◽  
Static And Dynamic Loading

Significant changes have been incorporated in design limits for pressurized vessels in Section VIII, Division 3 of the ASME Code, starting in 2007. There is now a local damage-mechanics based strain-exhaustion limit as well as a separate global plastic collapse limit. In addition, Code Case 2564 (Sec. VIII, Div 3) has recently been approved to address impulsively loaded vessels. Recent studies (Nakamura, T., Kaguchi, H., and Kubo, S., 2000, “Failure Strain of Thin Cylindrical Vessel Subjected to Dynamic Internal Pressure,” Design and Analysis of Pressure Vessels and Piping, Vol. 399, R. Baliga, ed., pp. 47–54 and Duffey, T. A., 2011, “Plastic Instabilities in Spherical Vessels for Static and Dynamic Loading,” ASME J. Pressure Vessel Technol., 133(5), p. 051210) have shown that local strain limits play a particularly important role for these impulsively loaded vessels. In this paper, the new local strain-exhaustion procedure, originally intended for static-pressure-loaded vessels, is evaluated for adequacy in conservatively predicting failure for impulsively loaded vessels. Based upon symmetrically loaded cylindrical shell geometry, it is found that direct extension of the new local failure rules in the ASME Code to impulsively loaded vessels is unconservative. However, a hoop-strain local failure criterion predicts failures reasonably well.

Protection Against Local Failure for Impulsively Loaded Vessels

2013 ◽  
Author(s):  
Alan M. Clayton ◽  
Thomas A. Duffey
Keyword(s):  
Damage Mechanics ◽  
Static Pressure ◽  
Local Strain ◽  
Local Failure ◽  
Hoop Strain ◽  
Direct Extension ◽  
Asme Code ◽  
Section Viii ◽  
Shell Geometry ◽  
Made In

Significant changes were recently made in design limits for pressurized vessels in Section VIII, Division 3 of the ASME Code. There is now a local damage-mechanics based strain-exhaustion limit as well as a separate global plastic collapse limit. In addition, Code Case 2564 (Sec VIII, Div 3) has recently been approved to address impulsively loaded vessels. Recent studies have shown that local strain limits play a particularly important role for these impulsively loaded vessels. In this paper, the new local strain-exhaustion procedure, originally intended for static-pressure-loaded vessels, is evaluated for adequacy in conservatively predicting failure for impulsively loaded vessels. Based upon a symmetrically loaded cylindrical shell geometry, it is found that direct extension of the new local failure rules in the ASME Code to impulsively loaded vessels is unconservative. However, a hoop-strain local failure criterion predicts failures reasonably well.

Design Formulas of Blind End Closures for High Pressure Vessels

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Maximum Stress ◽  
Accurate Determination ◽  
Pressure Vessels ◽  
Stress Distributions ◽  
Fatigue And Fracture ◽  
Asme Code ◽  
Section Viii

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.

Fitness-for-Service Strategies for Impulsively Loaded Vessels

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Thomas A. Duffey ◽  
Kevin R. Fehlmann
Keyword(s):  
Pressure Vessels ◽  
Material Behavior ◽  
Remaining Life ◽  
Structural Damping ◽  
Asme Code ◽  
Simplifying Assumptions ◽  
Section Viii ◽  
Repeated Use ◽  
Internal Blast Loading ◽  
Service Strategies

Abstract High-explosive containment vessels are often designed for repeated use, implying predominately elastic material behavior. Each explosive test imparts an impulse to the vessel wall. The vessel subsequently vibrates as a result of the internal blast loading, with amplitude diminishing exponentially in time after a few cycles due to structural damping. Flaws present in the vessel, as well as new flaws induced by fragment impact during testing, could potentially grow by fatigue during these vibrations. Subsequent explosive tests result in new sequences of vibrations, providing further opportunity for flaws to grow by fatigue. The obvious question is, How many explosive experiments can be performed before flaws potentially grow to unsafe limits? Because ASME Code Case 2564-5 (Impulsively Loaded Pressure Vessels) has just been incorporated in Section VIII, Division 3 of the 2019 ASME Boiler and Pressure Vessel Code, evaluation of remaining life and fitness-for-service of explosive containment vessels now draws upon two interrelated codes and standards: ASME Section VIII-3 and API-579/ASME FFS-1. This paper discusses their implementation in determining the remaining life of dynamically loaded vessels that have seen service and are potentially damaged. Results of a representative explosive containment vessel are presented using actual flaw data for both embedded weld flaws and fragment damage. Because of the potentially large number of flaws that can be detected by modern nondestructive inspection methods, three simplifying assumptions and a procedure are presented for conservatively eliminating from further consideration the vast majority of the flaws that possess considerable remaining life.

Application of ASME Section VIII Division 3 Design Requirements to Offshore High Pressure Equipment

2013 ◽  
Author(s):  
J. Robert Sims
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Local Strain ◽  
Pressure Vessels ◽  
Stress Concentrations ◽  
Section Viii ◽  
Design Requirements ◽  
Offshore Oil And Gas ◽  
Materials Used ◽  
Offshore Oil

Offshore oil and gas wells are being drilled into formations that have pressures up to 200 MPa (30,000 psi) and temperatures over 175°C (350°F). Most of the existing API Standards for pressure equipment, such as valves and blow out preventers (BOPs), are limited to pressures of about 100 MPa (15,000 psi). The design requirements in ASME Section VIII Division 3, Alternative Rules for Construction of High Pressure Vessels (Div. 3), can be adapted for the design of this equipment with some modifications. Since the strength of the materials used in these applications is limited due to environmental cracking concerns, it is necessary to accept some local yielding in areas of stress concentrations. Therefore, it is particularly important to apply the elastic-plastic analysis requirements in Div. 3 with appropriate limits on local strain as well as the robust fracture mechanics based fatigue analysis requirements. Paper published with permission.

Evaluation of ASME Pressure Vessel Code Prohibitions on Rod and Bar Stock and Potential Remedies

2014 ◽  
Author(s):  
John J. Aumuller ◽  
Vincent A. Carucci
Keyword(s):  
Pressure Vessels ◽  
Early 20Th Century ◽  
Economic Disadvantage ◽  
User Experiences ◽  
The Public ◽  
Division 1 ◽  
Asme Code ◽  
Billet Material ◽  
Section Viii ◽  
Division 2

The ASME Codes and referenced standards provide industry and the public the necessary rules and guidance for the design, fabrication, inspection and pressure testing of pressure equipment. Codes and standards evolve as the underlying technologies, analytical capabilities, materials and joining methods or experiences of designers improve; sometimes competitive pressures may be a consideration. As an illustration, the design margin for unfired pressure vessels has decreased from 5:1 in the earliest ASME Code edition of the early 20th century to the present day margin of 3.5:1 in Section VIII Division 1. Design by analysis methods allow designers to use a 2.4:1 margin for Section VIII Division 2 pressure vessels. Code prohibitions are meant to prevent unsafe use of materials, design methods or fabrication details. Codes also allow the use of designs that have proven themselves in service in so much as they are consistent with mandatory requirements and prohibitions of the Codes. The Codes advise users that not all aspects of construction activities are addressed and these should not be considered prohibited. Where prohibitions are specified, it may not be readily apparent why these prohibitions are specified. The use of “forged bar stock” is an example where use in pressure vessels and for certain components is prohibited by Codes and standards. This paper examines the possible motive for applying this prohibition and whether there is continued technical merit in this prohibition, as presently defined. A potential reason for relaxing this prohibition is that current manufacturing quality and inspection methods may render a general prohibition overly conservative. A recommendation is made to better define the prohibition using a more measurable approach so that higher quality forged billets may be used for a wider range and size of pressure components. Jurisdictions with a regulatory authority may find that the authority is rigorous and literal in applying Code provisions and prohibitions can be particularly difficult to accept when the underlying engineering principles are opaque. This puts designers and users in these jurisdictions at a technical and economic disadvantage. This paper reviews the possible engineering considerations motivating these Code and standard prohibitions and proposes modifications to allow wider Code use of “high quality” forged billet material to reflect some user experiences.

Overview of Revisions to the ASME Boiler and Pressure Vessel Code Section VIII Division 3 for the 2017 Edition and Near Future

2017 ◽  
Author(s):  
Daniel Peters ◽  
Gregory Mital ◽  
Adam P. Maslowski
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Central Area ◽  
Local Strain ◽  
Pressure Vessels ◽  
Conformity Assessment ◽  
Inspection Planning ◽  
Section Viii ◽  
American Society ◽  
Rules Changes

This paper provides an overview of the significant revisions pending for the upcoming 2017 edition of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) Section VIII Division 3, Alternative Rules for Construction of High Pressure Vessels, as well as potential changes to future editions under consideration of the Subgroup on High Pressure Vessels (SG-HPV). Changes to the 2017 edition include the removal of material information used in the construction of composite reinforced pressure vessels (CRPV); this information has been consolidated to the newly-developed Appendix 10 of ASME BPVC Section X, Fiber-Reinforced Plastic Pressure Vessels. Similarly, the development of the ASME CA-1, Conformity Assessment Requirements standard necessitated removal of associated conformity assessment information from Section VIII Division 3. Additionally, requirements for the assembly of pressure vessels at a location other than that listed on the Certificate of Authorization have been clarified with the definitions of “field” and “intermediate” sites. Furthermore, certain design related issues have been addressed and incorporated into the current edition, including changes to the fracture mechanics rules, changes to wires stress limits in wire-wound vessels, and clarification on bolting and end closure requirements. Finally, the removal of Appendix B, Suggested Practice Regarding Post-Construction Requalification for High Pressure Vessels, will be discussed, including a short discussion of the new appendix incorporated into the updated edition of ASME PCC-3, Inspection Planning Using Risk Based Methods. Additionally, this paper discusses some areas in Section VIII Division 3 under consideration for improvement. One such area involves consolidation of material models presented in the book into a central area for easier reference. Another is the clarification of local strain limit analysis and the intended number and types of evaluations needed for the non-linear finite element analyses. The requirements for test locations in prolongations on forgings are also being examined as well as other material that can be used in testing for vessel construction. Finally, a discussion is presented on an ongoing debate regarding “occasional loads” and “abnormal loads”, their current evaluation, and proposed changes to design margins regarding these loads.

Local Failure Analysis of Bolted Flanges

2020 ◽  
Author(s):  
Qi Li ◽  
Rafal Sulwinski ◽  
Charles Boellstorff
Keyword(s):  
Stress State ◽  
Plastic Strain ◽  
Internal Pressure ◽  
Local Strain ◽  
Local Failure ◽  
Strain Limit ◽  
Section Viii ◽  
Large Spike ◽  
Division 2 ◽  
Triaxiality Factor

Abstract Protection against local failure is one of the integral components in the design-by-analysis requirements in ASME BPVC Section VIII, Division 2. Of the methods offered by the ASME, the Local Strain Limit procedure outlined in 5.3.3.1 is the typical calculation method. However, it has been found that relying on this procedure alone can lead to untenable utilization results if used on certain analyses with varied load paths. The flange described in this study was calculated using “design by analysis” according to Part 5 of ASME BPVC Section VIII, Division 2. The elastic-plastic stress analysis method was used. The flange was loaded with an initial bolt pre-tension and then with internal pressure. During the local failure calculation, an abnormal condition was encountered in the form of a large spike in the history curve of the ratio between plastic strain and limiting triaxial strain. An investigation found that despite being in a stress state below yield stress, some nodes had a non-zero plastic strain and high triaxiality factor. This was caused by the load sequence: first, the bolt pre-tension and then internal pressure. The flange was first bent due to the pre-tension load, and later experienced bending in the opposite direction after the internal pressure load was applied. This resulted in a relatively low stress state with a high triaxiality factor and non-zero plastic strain in certain areas, which then showed high utilization under the local failure strain limit criterion. This paper will discuss how this issue can be avoided by using the strain limit damage calculation procedure 5.3.3.2 outlined in ASME BPVC Section VIII, Division 2.

Fatigue Consideration of Layered Vessels

2020 ◽  
Author(s):  
Kang Xu ◽  
Mahendra Rana ◽  
Maan Jawad
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Cost Effective ◽  
Pressure Vessels ◽  
Asme Code ◽  
Section Viii ◽  
Cyclic Service ◽  
Gap Height ◽  
Technical Basis ◽  
Division 2

Abstract Layered pressure vessels provide a cost-effective solution for high pressure gas storage. Several types of designs and constructions of layered pressure vessels are included in ASME BPV Section VIII Division 1, Division 2 and Division 3. Compared with conventional pressure vessels, there are two unique features in layered construction that may affect the structural integrity of the layered vessels especially in cyclic service: (1) Gaps may exist between the layers due to fabrication tolerances and an excessive gap height introduces additional stresses in the shell that need to be considered in design. The ASME Codes provide rules on the maximum permissible number and size of these gaps. The fatigue life of the vessel may be governed by the gap height due to the additional bending stress. The rules on gap height requirements have been updated recently in Section VIII Division 2. (2) ASME code rules require vent holes in the layers to detect leaks from inner shell and to prevent pressure buildup between the layers. The fatigue life may be limited by the presence of stress concentration at vent holes. This paper reviews the background of the recent code update and presents the technical basis of the fatigue design and maximum permissible gap height calculations. Discussions are made in design and fabrication to improve the fatigue life of layered pressure vessels in cyclic service.

Rectangular Pressure Vessels of Finite Length

1990 ◽  
Vol 112 (1) ◽  
pp. 50-56 ◽  
Author(s):  
A. E. Blach ◽  
V. S. Hoa ◽  
C. K. Kwok ◽  
A. K. W. Ahmed
Keyword(s):  
Finite Length ◽  
Design Method ◽  
Circular Cross Section ◽  
Pressure Vessels ◽  
Small Deflection ◽  
Asme Code ◽  
Test Pressure ◽  
Section Viii ◽  
Deflection Theory ◽  
Large Deflection Theory

Design Rules in the ASME Code, Section VIII, Division 1, cover the design of unreinforced and reinforced rectangular pressure vessels. These rules are based on “infinitely long” vessels of non-circular cross section and stresses calculated are based on a linearized “small deflection” theory of plate bending. In actual practice, many pressure vessels can be found which are of finite length, often operating successfully under pressures two to three times as high as those permitted under the Code rules cited. This paper investigates the effects of finite length on the design formulae given by the ASME Code, and also a design method based on “large deflection” theory coefficients for short rectangular pressure vessels. Results based on analysis are compared with values obtained from finite element computations, and with experimental data from strain gage measurements on a test pressure vessel.

New Common Design Rules for U-Tube Heat Exchangers in ASME, CODAP and UPV Codes

2002 ◽  
Author(s):  
F. Osweiller
Keyword(s):  
Heat Exchangers ◽  
Pressure Vessels ◽  
Design Rule ◽  
Technical Approach ◽  
Design Rules ◽  
Asme Code ◽  
European Code ◽  
Section Viii ◽  
Technical Basis ◽  
Year 2000

In year 2000, ASME Code (Section VIII – Div. 1), CODAP (French Code) and UPV (European Code for Unfired Pressure Vessels) have adopted the same rules for the design of U-tube tubesheet heat exchangers. Three different rules are proposed, based on different technical basis, to cover: • Tubesheet gasketed with shell and channel. • Tubesheet integral with shell and channel. • Tubesheet integral with shell and gasketed with channel or the reverse. At the initiative of the author, a more refined technical approach has been developed, to cover all tubesheet configurations. The paper explains the rationale for this new design rule which is being incorporated in ASME, CODAP and UPV in 2002. This is substantiated with comparisons to TEMA Standards and a benchmark of numerical comparisons.

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