scholarly journals Stress Linearization Concepts and Restrictions in Elastic Design by Analysis

2017 ◽  
Author(s):  
Don Mackenzie
Keyword(s):  
Stress Analysis ◽  
Pressure Vessel ◽  
Elastic Stress ◽  
Limit State ◽  
Design Procedure ◽  
Limit Load ◽  
Stress Distributions ◽  
Shakedown Analysis ◽  
Shell Analysis ◽  
Elastic Design

Stress linearization is widely used in Pressure vessel Design by Analysis based on elastic stress analysis and stress categorization. This paper investigates the structural mechanics basis of stress linearization in the context of limit and shakedown analysis and proposes a new basis for the procedure that relates the stress along a line to the concept of limit load. This removes the need for some conceptual requirements associated with shell analysis from stress linearization, including restriction of SCL location to identified bending planes. It also introduces the concept of selecting stress distributions representative of the limit state to remove the need for some elements of stress categorization in the design procedure.

Limit Load Analysis of Cylindrical Vessels Under Internal Pressure and Axial Strain

2011 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Internal Pressure ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Axial Strain ◽  
Limit State ◽  
Limit Load ◽  
Operating Pressure ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Load Analysis

Strain-based design is a newer technology used in safety design and integrity management of oil and gas pipelines. In a traditional stress-based design, the axial stress is relatively small compared to the hoop stress generated by internal pressure in a line pipe, and the limit state in the pipeline is usually load-controlled. In a strain-based design, however, axial strain can be large and the load-carrying capacity of pipelines could be reduced significantly below an allowed operating pressure, where the limit state is controlled by an axial strain. In this case, the limit load analysis is of great importance. The present paper confirms that the stress, strain and load-carrying capacity of a thin-walled cylindrical pressure vessel with an axial force are equivalent those of a long pressurized pipeline with an axial tensile strain. Elastic stresses and strains in a pressure vessel are then investigated, and the limit stress, limit strain and limit pressure are obtained in terms of the classical Tresca criterion, von Mises criteria, and a newly proposed average shear stress yield criterion. The results of limit load solutions are analyzed and validated using typical experimental data at plastic yield.

Overview of Revisions to the ASME Boiler and Pressure Vessel Code Section VIII Division 3 for the 2015 Edition and Near Future

2015 ◽  
Author(s):  
Daniel Peters ◽  
Adam P. Maslowski
Keyword(s):  
High Pressure ◽  
Stress Analysis ◽  
Pressure Vessel ◽  
Elastic Stress ◽  
Pressure Vessels ◽  
Chemical Safety ◽  
Linear Elastic ◽  
Section Viii ◽  
American Society ◽  
Near Future

This paper is to give an overview of the major revisions pending in the upcoming 2015 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, and potential changes being considered by the Subgroup on High Pressure Vessels (SG-HPV) for future editions. This will include an overview of significant actions which will be included in the upcoming edition. This includes action relative to test locations in large and complex forgings, in response to a report from the U.S. Chemical Safety and Hazard Investigation Board (CSB) report of a failed vessel in Illinois. This will also include discussion of a long term issue recently completed on certification of rupture disk devices. Also included will be a discussion of a slight shift in philosophy which has resulted in the linear-elastic stress analysis section being moved to a Non-Mandatory Appendix and discussion of potential future of linear-elastic stress analysis in high pressure vessel design.

A Comparison of Design by Analysis Techniques for Evaluating Nozzle-to-Shell Junctions per ASME Section VIII Division 2

2015 ◽  
Author(s):  
Phillip E. Prueter ◽  
Robert G. Brown
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Elastic Stress ◽  
Limit Load ◽  
Plastic Collapse ◽  
Elastic Plastic ◽  
Plastic Analysis ◽  
Non Linear ◽  
Section Viii ◽  
Division 2

Part 5 of ASME Section VIII Division 2 offers several design by analysis (DBA) techniques for evaluating pressure retaining equipment for Code compliance using detailed computational stress analysis results. These procedures can be used to check components for protection against multiple failure modes, including plastic collapse, local failure, buckling, and cyclic loading. Furthermore, these procedures provide guidance for establishing consistent loading conditions, selecting material properties, developing post-processing techniques, and comparing analysis results to the appropriate acceptance criteria for a given failure mode. In particular, this study investigates the use of these methods for evaluating nozzle-to-shell junctions subjected to internal pressure and nozzle end loads. Specifically, elastic stress analysis, limit load analysis, and elastic-plastic stress analysis are utilized to check for protection against plastic collapse, and computational results for a given load case are compared. Additionally, the twice elastic slope method for evaluating protection against plastic collapse is utilized as an alternate failure criterion to supplement elastic-plastic analysis results. The goal of these comparisons is to highlight the difference between elastic stress checks and the non-linear analysis methodologies outlined in ASME Section VIII Division 2; particularly, the conservatism associated with employing the elastic stress criterion for nozzle end loads compared to limit load and elastic-plastic analysis methodologies is discussed. Finally, commentary on the applicability of performing the Code-mandated check for protection against ratcheting for vessels that do not operate in cyclic service is provided. The intent of this paper is to provide a broad comparison of the available DBA techniques for evaluating the acceptability of nozzle-to-shell junctions subjected to different types of loading for protection against plastic collapse. Predicted deformations and stresses are quantified for each technique using linear and non-linear, three-dimensional finite element analysis (FEA) methodologies.

Prediction of the Low Cycle Fatigue Life of Pressure Vessels

1967 ◽  
Vol 89 (4) ◽  
pp. 858-868 ◽  
Author(s):  
A. G. Pickett ◽  
S. C. Grigory
Keyword(s):  
Fatigue Life ◽  
Stress Analysis ◽  
Pressure Vessel ◽  
Low Cycle Fatigue ◽  
Design Procedure ◽  
Pressure Vessels ◽  
Analysis Method ◽  
Notch Stress ◽  
Fatigue Life Analysis ◽  
Fatigue Evaluation

The bases for ASME Boiler and Pressure Vessel Code, Section III, fatigue evaluation procedures, the fracture mechanics approach to fatigue life analysis, and the notch stress analysis method are reviewed. Fatigue life predictions are compared with the results of materials, model, and full size pressure vessel tests performed for PVRC and AEC. These tests were made in response to the research objectives established by ASME Special Committee to Review Code Stress Basis in 1958. A proposed design procedure based on the notch stress analysis method and experimental results is presented.

Limit Load Bounds for the mα Multiplier

2003 ◽  
Vol 125 (1) ◽  
pp. 11-18 ◽  
Author(s):  
W. D. Reinhardt ◽  
R. Seshadri
Keyword(s):  
Elastic Modulus ◽  
Limit Analysis ◽  
Strain Distribution ◽  
Limit State ◽  
Limit Load ◽  
Stress Redistribution ◽  
Stress And Strain ◽  
Plastic Collapse ◽  
Stress Distributions ◽  
Stress And Strain Distribution

Limit analysis is an important tool to assess the integrity of a structure. Successive elastic modulus adjustment, in particular, can simulate the plastic stress redistribution in a structure at the limit state (plastic collapse). Several limit load estimates have been developed based on the stress and strain distribution within a component. The bounding nature of these estimates is examined in this paper. Particular emphasis is given to the limit load estimate mα, which has been proposed to give improved limit load predictions from partly converged stress distributions in the structure. Bounds on the accuracy of these mα predictions are derived.

Design Optimization of Pressure Vessel in Compliance With Elastic Stress Analysis Criteria for Plastic Collapse Using an Integrated Approach

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Mingjue Zhou ◽  
Artik Patel ◽  
BoPing Wang ◽  
Weiya Jin ◽  
Yuebing Li
Keyword(s):  
Stress Analysis ◽  
Design Optimization ◽  
Pressure Vessel ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Integrated Approach ◽  
Optimization Methods ◽  
Pressure Vessels ◽  
Design Codes ◽  
Division 2

Abstract The design and verification of pressure vessels is governed by the design codes specified by the ASME Boiler and Pressure Vessel Code (BPVC). Convention design satisfying the ASME BPVC code requirements would lead to a conservative design. This situation will to be solvable by modern structural optimization methods. The size optimization of pressure vessel complying with design-by-analysis requirements within the ASME Sec. VIII Division 2 specification is discussed in this paper. This is accomplished by an integrated approach in which the stress analysis is carried out by ANSYS. These results are used by an optimization code in matlab to perform design optimization. The integrated approach is fully automated and applied to the optimal design of a real pressure vessel. The results show that the material used by the pressure vessel can be minimized while satisfying the maximum stress specified in the BPVC.

Discussion on the Implementation of the Primary Structure Method in Design by Analysis

2016 ◽  
Vol 853 ◽  
pp. 341-345
Author(s):  
Cheng Hong Duan ◽  
Li Wei Ding ◽  
Ming Wan Lu
Keyword(s):  
Cylindrical Shell ◽  
Stress Intensity ◽  
Stress Analysis ◽  
Primary Structure ◽  
Pressure Vessel ◽  
Elastic Stress ◽  
Original Structure ◽  
Analysis Method ◽  
Stress Classification ◽  
Axisymmetric Structure

The implementation of the primary structure method in design by analysis of pressure vessel is discussed. With two examples of axisymmetric structure of pressure vessel, flat head-cylindrical shell joint and flange-ellipsoidal head joint, the primary structure is constructed according to the principle of this method with ANSYS. By comparing the stress intensity and deformation of the primary structure with that of the original structure, the primary and secondary stress along the stress classification line can be clearly distinguished by using the primary structure method. It has great application value in dealing with stress classification in the elastic stress analysis method. The results also show that a variety of reasonable primary structures can be constructed based on the same original structure, and the primary structure method has some flexibility.

A Comparison Study of Pressure Vessel Design Using Different Standards

2013 ◽  
Author(s):  
Frode Tjelta Askestrand ◽  
Ove Tobias Gudmestad
Keyword(s):  
Stress Analysis ◽  
Elastic Stress ◽  
Limit Load ◽  
Technical Committee ◽  
Pressure Vessels ◽  
Analysis Method ◽  
Elastic Plastic ◽  
Load Analysis ◽  
American Society ◽  
Division 2

Several codes are currently available for design and analysis of pressure vessels. Two of the main contributors are the American Society of Mechanical Engineers providing the ASME VIII code, Ref /4/ and the Technical Committee for standardization in Brussels providing the European Standard, Ref /2/. Methods written in bold letters will be considered in the discussion presented in this paper. The ASME VIII code, Ref /4/, contains three divisions covering different pressure ranges: Division 1: up to 200 bar (3000 psi) Division 2: in general Division 3: for pressure above 690 bar (10000 psi) In this paper the ASME division 2, Part 5, “design by analysis” will be considered. This part is also referred to in the DNV-OS-F101, Ref /3/, for offshore pressure containing components. Here different analysis methods are described, such as: Elastic Stress Analysis Limit Load Analysis Elastic Plastic Analysis The Elastic Stress Analysis method with stress categorization has been introduced to the industry for many years and has been widely used in design of pressure vessels. However, in the latest issue (2007/2010) of ASME VIII div. 2, this method is not recommended for heavy wall constructions as it might generate non-conservative analysis results. Heavy wall constructions are defined by: (R/t ≤ 4) with dimensions as illustrated in Figure 1. In the case of heavy wall constructions the Limit Load Analysis or the Elastic-plastic method shall be used. In this paper focus will be on the Elastic-plastic method while the Limit Load Analysis will not be considered. Experience from recent projects at IKM Ocean Design indicates that the industry has not been fully aware of the new analysis philosophy mentioned in the 2007 issue of ASME VIII div.2. The Elastic Stress Analysis method is still (2012) being used for heavy wall constructions. The NS-EN 13445-3; 2009, Ref /2/, provides two different methodologies for design by analysis: Direct Route Method based on stress categories. The method based on stress categories is similar to the Elastic Stress Analysis method from ASME VIII div. 2 and it will therefore not be considered in this paper.

Stress Field Around a Large Opening in a Pressure Vessel During a Major Repair

2009 ◽  
Author(s):  
Erik Garrido ◽  
Euro Casanova
Keyword(s):  
Pressure Vessel ◽  
New Technologies ◽  
Mechanical Design ◽  
General Purpose ◽  
Pressure Vessels ◽  
Mechanical Equipment ◽  
Stress Distributions ◽  
Large Opening ◽  
Von Mises ◽  
Case Basis

It is a regular practice in the oil industry to modify mechanical equipment to incorporate new technologies and to optimize production. In the case of pressure vessels, it is occasionally required to cut large openings in their walls in order to have access to the interior part of the equipment for executing modifications. This cutting process produces temporary loads, which were obviously not considered in the original mechanical design. Up to now, there is not a general purpose specification for approaching the assessments of stress levels once a large opening in a vertical pressure vessel has been made. Therefore stress distributions around large openings are analyzed on a case-by-case basis without a reference scheme. This work studies the distribution of the von Mises equivalent stresses around a large opening in FCC Regenerators during internal cyclone replacement, which is a frequently required practice for this kind of equipment. A finite element parametric model was developed in ANSYS, and both numerical results and illustrating figures are presented.

Sign in / Sign up

Export Citation Format

Share Document