Strength Criteria Versus Plastic Flow Criteria Used in Pressure Vessel Design and Analysis1

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Plastic Flow ◽  
Pressure Vessel ◽  
Yield Criterion ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Thin Wall ◽  
Strength Criteria ◽  
Integrity Assessment ◽  
Ductile Materials ◽  
Strength Design Criteria

This paper presents a critical comparison of the traditional strength criteria and the modern plastic flow criteria used in the structural design and integrity assessment of pressure vessels. This includes (1) a brief review of the traditional strength criteria used in the ASME Boiler and Pressure Vessel (B&PV) Code, (2) a discussion of the shortcomings of the traditional strength criteria when used to predict the burst pressure of pressure vessels, (3) an analysis of challenges, technical gaps, and basic needs to improve the traditional strength criteria, (4) a comparison of strength theories and plasticity theories for ductile materials, (5) an evaluation of available plastic flow criteria and their drawbacks in prediction of burst pressure of pressure vessels, (6) a description of a newly developed multiaxial yield criterion and its application to pressure vessels, and (7) a demonstration of experimental validation of the new plastic flow criterion when used to predict the burst pressure of thin-wall pressure vessels. Finally, recommendations are made for further study to improve the traditional strength design criteria and to facilitate utilization of the modern plastic flow criteria for pressure vessel design and analysis.

Evaluation of Strength Design Criteria and Plastic Flow Criteria for Pressure Vessels

2014 ◽  
Author(s):  
Xian-Kui Zhu
Keyword(s):  
Plastic Flow ◽  
Axial Flow ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Design Criteria ◽  
Strength Criteria ◽  
Integrity Assessment ◽  
Strength Design ◽  
Strength Design Criteria ◽  
Flow Criterion

The present paper evaluates the traditional strength design criteria and recently developed plastic flow criteria used in the structural design and integrity assessment for pressure vessels. This includes (1) a brief review of the traditional strength criteria used in ASME Boiler and Pressure Vessel (B&PV) Code, (2) a discussion of the shortcoming of existing strength criteria when used to predict the burst pressure of pressure vessels, (3) an analysis of challenges, technical gaps and basic needs to improve the traditional strength design criteria, (4) a comparison of strength theory and flow theory for ductile pressure vessels, (5) an evaluation of available flow criteria and their shortcoming in prediction of failure pressure of pressure vessels, (6) an introduction of newly developed multi-axial flow criterion and its application to pressure vessels, and (7) a demonstration of experimental validations of the new flow criterion when used to predict the burst pressure of pressure vessels. On this basis, several recommendations are made for further study to improve the existing strength design and integrity assessment methods of pressure vessels.

Burst Pressure Prediction of Cylindrical Vessels Using Artificial Neural Network

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Abolfazl Zolfaghari ◽  
Moein Izadi
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Machine Learning Techniques ◽  
Burst Pressure ◽  
Outer Diameter ◽  
Wide Range ◽  
Artificial Neural ◽  
Predictor Model

Abstract Pressure vessel plays an important role in wide range of applications to store gas or liquid substances. In order to design a pressure vessel safely, one of the main factors which has to be considered is selection of proper burst pressure perdition criterion. Due to large range of available materials in manufacturing of the vessels under different working conditions, several criteria to forecast burst pressure of the vessels have been developed and used by designers. Choosing the most proper criterion based on working condition and the material is a vital task to meet design requirements because inappropriate criterion may lead to unsafe vessel or over design. This issue makes not only pressure vessel design more complex but also maintenance planning, especially for designers who do not have enough experience, is a challenging task. Therefore, lack of a burst pressure predictor model, which is able to determine the pressure more accurately for wide range of materials and applications, has been remained unsolved. To evaluate machine learning techniques in prediction of burst pressure of pressure vessels, in this paper, a new model based on artificial neural network (ANN) has been proposed and developed. Input parameters of the model include internal and outer diameter, thickness, ultimate and yield strength; output is burst pressure. The obtained results showed that the constructed model has a good potential to be used as more applicable model compared to current models in design of pressure vessels.

Flaw Testing of Fiber Reinforced Composite Pressure Vessels

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
John Makinson ◽  
Norman L. Newhouse
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Project Team ◽  
Burst Pressure ◽  
Depth Of Cut ◽  
Test Program ◽  
Pressure Cycling ◽  
Structural Composite ◽  
Design Pressure ◽  
Composite Pressure Vessels

The ASME Boiler Pressure Vessel Project Team on Hydrogen Tanks, in conjunction with other ASME Codes and Standards groups, is developing Code Cases and revisions to the Boiler and Pressure Vessel Code, including such to address the design of composite pressure vessels. The Project Team had an interest in further understanding the effect of cuts to the surface of composite tanks, and how the burst pressure would be affected during the lifetime of the pressure vessel. A test program was initiated to provide data on initial burst pressure, and burst pressure after pressure cycling, of composite cylinders with cuts of different depth. This test program was conducted by Lincoln Composites under contract to ASME Standards Technology LLC, and was funded by National Renewable Energy Laboratory (NREL) [1]. These results were considered during the development and approval of the ASME Code Cases and Code Rules. Thirteen pressure vessels with a design pressure of 24.8 MPa (3600 psi), approximately 0.406 m (16.0 in.) in diameter and 1.02 m (40.2 in.) long, were tested to investigate the effects of cuts to the structural laminate of a composite overwrapped pressure vessel with respect to cycling and burst pressure. Two flaws, one longitudinal and one circumferential, were machined into the structural composite. The flaws were 57 mm long by 1 mm wide (2.25 in. × 0.04 in.) and varied in depth from 10% to 40% of the structural composite thickness of 11.4 mm (0.45 in.). These pressure vessels were cycled to design pressure 0, 10,000, and 20,000 times then burst. The resulting burst pressures were evaluated against the performance of a pressure vessel without flaws or cycling. The burst pressures were affected by depth of cut, but the pressure cycling did not have a significant effect on the burst pressure.

Ways for Extending the Reactor Pressure Vessel Lifetime

2008 ◽  
Author(s):  
Milan Brumovsky
Keyword(s):  
Pressure Vessel ◽  
Nuclear Power ◽  
Pressure Vessels ◽  
Reactor Pressure Vessel ◽  
Integrity Assessment ◽  
Low Leakage ◽  
Vessel Integrity ◽  
Direct Use ◽  
Reactor Pressure ◽  
Lifetime Extension

Reactor pressure vessels are components that usually determine the lifetime of the whole nuclear power plant and thus also its efficiency and economy. There are several ways how to ensure conditions for reactor pressure vessel lifetime extension, mainly: - pre-operational, like: • optimal design of the vessel; • proper choice of vessel materials and manufacturing technology; - operational, like: • application of low-leakage core; • increase of water temperature in ECCS; • insertion of dummy elements; • vessel annealing; • decrease of conservatism during reactor pressure vessel integrity assessment e.g. using direct use of fracture mechanics parameters, like “Master Curve” approach. All these ways are discussed in the paper and some qualitative as well as quantitative evaluation is given.

MAI Benchmark Campaign of International Software for Reactor Pressure Vessel Integrity Assessment

2014 ◽  
Author(s):  
Emilie Dautreme ◽  
Emmanuel Remy ◽  
Roman Sueur ◽  
Jean-Philippe Fontes ◽  
Karine Aubert ◽  
...  
Keyword(s):  
United States ◽  
Pressure Vessel ◽  
Software Tool ◽  
The United States ◽  
Pressure Vessels ◽  
Reactor Pressure Vessel ◽  
Pressurized Water ◽  
Integrity Assessment ◽  
Benchmark Study ◽  
Reactor Pressure

Nuclear Reactor Pressure Vessel (RPV) integrity is a major issue concerning plant safety and this component is one of the few within a Pressurized Water Reactor (PWR) whose replacement is not considered as feasible. To ensure that adequate margins against failure are maintained throughout the vessel service life, research engineers have developed and applied computational tools to study and assess the probability of pressure vessel failure during operating and postulated loads. The Materials Ageing Institute (MAI) sponsored a benchmark study to compare the results from software developed in France, Japan and the United States to compute the probability of flaw initiation in reactor pressure vessels. This benchmark study was performed to assess the similarities and differences in the software and to identify the sources of any differences that were found. Participants in this work included researchers from EDF in France, CRIEPI in Japan and EPRI in the United States, with each organization using the probabilistic software tool that had been developed in their country. An incremental approach, beginning with deterministic comparisons and ending by assessing Conditional Probability of crack Initiation (CPI), provided confirmation of the good agreement between the results obtained from the software used in this benchmark study. This conclusion strengthens the confidence in these probabilistic fracture mechanics tools and improves understanding of the fundamental computational procedures and algorithms.

Flaw Testing of Fiber Reinforced Composite Pressure Vessels

2010 ◽  
Author(s):  
John Makinson ◽  
Norman L. Newhouse
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Project Team ◽  
Burst Pressure ◽  
Depth Of Cut ◽  
Test Program ◽  
Pressure Cycling ◽  
Structural Composite ◽  
Design Pressure ◽  
Composite Pressure Vessels

The ASME BPV Project Team on Hydrogen Tanks, in conjunction with other ASME Codes and Standards groups, is developing Code Cases and revisions to the Boiler & Pressure Vessel Code, including such to address the design of composite pressure vessels. The Project Team had an interest in further understanding the effect of cuts to the surface of composite tanks, and how the burst pressure would be affected during the lifetime of the pressure vessel. A test program was initiated to provide data on initial burst pressure, and burst pressure after pressure cycling, of composite cylinders with cuts of different depth. This test program was conducted by Lincoln Composites under contract to ASME Standards Technology LLC, and was funded by NREL. These results were considered during the development and approval of the ASME Code Cases and Code Rules. Thirteen pressure vessels with a design pressure of 24.8 MPa (3600 psi), approximately 0.406 meter (16.0 inches) in diameter and 1.02 meters (40.2 inches) long, were tested to investigate the effects of cuts to the structural laminate of a composite overwrapped pressure vessel with respect to cycling and burst pressure. Two flaws, one longitudinal and one circumferential, were machined into the structural composite. The flaws were 57 mm long by 1 mm wide (2.25 inch × 0.04 inch) and varied in depth from 10% to 40% of the structural composite thickness of 11.4 mm (0.45 inch). These pressure vessels were cycled to design pressure 0, 10,000 and 20,000 times then burst. The resulting burst pressures were evaluated against the performance of a pressure vessel without flaws or cycling. The burst pressures were affected by depth of cut, but the pressure cycling did not have a significant effect on the burst pressure.

Weld Material Investigations of a WWER-440 Reactor Pressure Vessel: Results From the First Trepan Taken From the Former Greifswald NPP

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Udo Rindelhardt ◽  
Hans-Werner Viehrig ◽  
Joerg Konheiser ◽  
Jan Schuhknecht
Keyword(s):  
Fracture Toughness ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Reactor Pressure Vessel ◽  
Reference Temperature ◽  
Monte Carlo Code ◽  
Data Set ◽  
Integrity Assessment ◽  
Inner Surface ◽  
Reactor Pressure

Between 1973 and 1990 four units of the Russian nuclear power plants type WWER-440/230 were operated in Greifswald (former East Germany). Material probes from the pressure vessels were gained in the frame of the ongoing decommissioning procedure. The investigations of this material started with material from the circumferential core weld of unit 1. First, this paper presents results of the reactor pressure vessel (RPV) fluence calculations depending on different loading schemes and on the axial weld position based on the Monte Carlo code TRAMO. The results show that the use of the dummy assemblies reduces the flux by a factor of 2–5 depending on the azimuthal position. The circumferential core weld (SN0.1.4) received a fluence of 2.4×1019 neutrons/cm2 at the inner surface; it decreases to 0.8×1019 neutrons/cm2 at the outer surface. The material investigations were done using a trepan from the circumferential core weld. The reference temperature T0 was calculated with the measured fracture toughness values, KJc, at brittle failure of the specimen. The KJc values show a remarkable scatter. The highest T0 was about 50°C at a distance of 22 mm from the inner surface of the weld. The Charpy transition temperature TT41J estimated with results of subsized specimens after the recovery annealing was confirmed by the testing of standard Charpy V-notch specimens. The VERLIFE procedure prepared for the integrity assessment of WWER RPV was applied on the measured results. The VERLIFE lower bound curve indexed with the Structural Integrity Assessment Procedures for European Industry (SINTAP) reference temperature, RTT0SINTAP, envelops the KJc values. Therefore for a conservative integrity assessment the fracture toughness curve indexed with a RT representing the brittle fraction of a data set of measured KJc values has to be applied.

Buckling Assessment of Carbon Steel Pressure Vessels During PWHT

2018 ◽  
Author(s):  
Shunji Kataoka
Keyword(s):  
Elevated Temperature ◽  
Carbon Steel ◽  
Structural Integrity ◽  
Strain Curve ◽  
Tensile Tests ◽  
Pressure Vessels ◽  
Vertical Position ◽  
Strength Criteria ◽  
Integrity Assessment ◽  
Steel Material

Post weld heat treatment (PWHT) is often applied to welded pressure vessels and piping to increase the mechanical and metallurgical properties. During the PWHT, a pressure component made of a carbon steel to which PWHT is applied, is heated up to the temperature around 620 deg.C with +/− 25 deg.C tolerances and that elevated temperature is kept for 1 to 2 hours. The local PWHT of the vertical pressure vessel is sometimes planned at a construction site with vertical position, because of some restrictions relating to construction, such as limited access route to the vessel location, and limited space large capacity cranes. In the situation, it is important to assure the structural stability during PWHT. Except wind loads, it is considered that the stress applied in the shell during PWHT is usually not significant, however there have been no published strength criteria corresponds to the PWHT conditions. In this paper, the new elevated temperature tensile tests and constant stress creep strain tests of A516-Gr.70, a typical carbon steel material for pressure vessels, are conducted. Several examples of the numerical analysis using isochronous stress strain curve considering creep effect are presented. From the test result, the importance of the consideration of the creep deformation on the structural integrity assessment of PWHT operation is clarified.

Study on the Structural Safety Evaluation for Pressure Vessel of the CNG Vehicle Using F.E.M.

2012 ◽  
Vol 569 ◽  
pp. 598-602 ◽  
Author(s):  
Eui Soo Kim ◽  
Jong Hyuk Kim ◽  
Byung Sun Moon ◽  
Jae Mo Goh
Keyword(s):  
Pressure Vessel ◽  
Storage Tank ◽  
Safety Management ◽  
Yield Criterion ◽  
Safety Evaluation ◽  
Pressure Vessels ◽  
Structural Safety ◽  
Test Procedures ◽  
Design Variables ◽  
Von Mises

CNG vehicles have to be equipped with a safe and reliable storage tank, such as composite pressure vessels, since the failure of the CNG storage tank induces fatal damages to passengers. In this research, the cause of vessel facture is investigated through formal inspection and engineering test procedures. Specifically, the composite pressure vessel design will be validated using the finite element method. In order to validate values of the optimal design variables in accordance with standard of the high pressure gas safety management, we used safety probability such as Von-Mises yield criterion, Tsai-Hill theory and stress ratio.

Effect of Strain-Hardening Exponent and Strain Concentrations on the Bursting Behavior of Pressure Vessels

1974 ◽  
Vol 96 (4) ◽  
pp. 292-298 ◽  
Author(s):  
C. P. Royer ◽  
S. T. Rolfe
Keyword(s):  
Yield Strength ◽  
Strain Hardening ◽  
Wall Thickness ◽  
Pressure Vessel ◽  
High Strength Steels ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Strain Hardening Exponent ◽  
Research Committee ◽  
Wide Range

Studies by the Subcommittee for Effective Utilization of Yield Strength of the Pressure Vessel Research Committee of the Welding Research Council have provided a better understanding of the behavior of pressure vessels in the bursting mode of failure. Specifically, these studies have shown that high-strength steels can be more effectively utilized in pressure vessel applications, and with appropriate safety. However, before specific Code changes are recommended, the possible influence of undetected sharp flaws on the burst pressure, as predicted by the modified Svensson equation, should be established. Accordingly, a study of six notched pressure vessels was conducted to establish the limitations of the Svensson equation with respect to severe strain concentrations, namely, sharp longitudinal notches. Three steels (A517, A516, and 304SS) having a wide range of strain-hardening exponents (0.09, 0.19, and 0.59) were used to fabricate thin-walled pressure vessels (16-in. (406 mm) O.D., 1/2 in. (13 mm) wall thickness, 48-in. (1.22 m) length). Each vessel had a 15-in. (381 mm) long sharp machined notch with flaw depths ranging from 15 to 35 percent of the wall thickness. These vessels were tested hydrostatically to burst at room temperature. All failures were ductile. The results indicate that for pressure vessel steels having nominal yield strength up to 115 ksi (793 MN/m2) and normal ductility and toughness, the modified Svensson equation can be used to predict burst pressure very reliably as long as the flaw depths are less than 25 percent of the wall thickness. On the basis of these test results, as well as burst tests of vessels with moderate strain concentrations such as nozzles and flat end closures, it is recommended that the terms Fcyl and Fsph (factors that describe the effect of strain-hardening exponent on the bursting behavior of cylinders and spheres) be incorporated into the appropriate Code provisions. It is further recommended that the appropriate Code committee consider a possible reduction in the factor of safety against bursting on the basis of the results of this investigation.

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