Optimal Shapes for Axisymmetric Pressure Vessels: A Brief Overview

2000 ◽  
Vol 122 (4) ◽  
pp. 443-449 ◽  
Author(s):  
Lei Zhu ◽  
J. T. Boyle
Keyword(s):  
Pressure Vessel ◽  
Limit Load ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Limit Pressure ◽  
Optimal Shapes ◽  
Load Carrying ◽  
Analysis System ◽  
Elastic Compensation Method

This paper describes how optimal shapes for axisymmetric pressure vessels can be established based on maximizing limit pressure. This type of problem has been rarely examined in the literature due to the difficulty of evaluating limit loads. However, the “elastic compensation method” is used to approximate the limit load using elastic analysis alone, which opens the possibility of studying shape optimization based on limit pressure. The basic procedure, using a commercial finite element analysis system, is described and three example problems are examined. The aim is to investigate how much of an increase in load-carrying capacity could potentially be achieved if nonstandard pressure vessel shapes could be employed in practice. Of course, this may not be possible, but the results described here do contribute to a better understanding of the role shape plays in providing strength to a simple pressure vessel. [S0094-9930(00)00304-8]

Investigation of Burst Pressure in T-Joints With Wall-Thinning by Using FEA

2017 ◽  
Author(s):  
Atsushi Yamaguchi
Keyword(s):  
Carrying Capacity ◽  
Safety Margin ◽  
Pressure Vessels ◽  
Burst Pressure ◽  
Load Carrying Capacity ◽  
Working Pressure ◽  
Element Analysis ◽  
T Joints ◽  
Wall Thinning ◽  
Load Carrying

Boilers and pressure vessels are heavily used in numerous industrial plants, and damaged equipment in the plants is often detected by visual inspection or non-destructive inspection techniques. The most common type of damage is wall thinning due to corrosion under insulation (CUI) or flow-accelerated corrosion (FAC), or both. Any damaged equipment must be repaired or replaced as necessary as soon as possible after damage has been detected. Moreover, optimization of the time required to replace damaged equipment by evaluating the load carrying capacity of boilers and pressure vessels with wall thinning is expected by engineers in the chemical industrial field. In the present study, finite element analysis (FEA) is used to evaluate the load carrying capacity in T-joints with wall thinning. Burst pressure is a measure of the load carrying capacity in T-joints with wall thinning. The T-joints subjected to burst testing are carbon steel tubes for pressure service STPG370 (JIS G3454). The burst pressure is investigated by comparing the results of burst testing with the results of FEA. Moreover, the maximum allowable working pressure (MAWP) of T-joints with wall thinning is calculated, and the safety margin for the burst pressure is investigated. The burst pressure in T-joints with wall thinning can be estimated the safety side using FEA regardless of whether the model is a shell model or a solid model. The MAWP is 2.6 MPa and has a safety margin 7.5 for burst pressure. Moreover, the MAWP is assessed the as a safety side, although the evaluation is too conservative for the burst pressure.

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.

Simple Bounds on Limit Loads by Elastic Finite Element Analysis

1993 ◽  
Vol 115 (1) ◽  
pp. 27-31 ◽  
Author(s):  
D. Mackenzie ◽  
C. Nadarajah ◽  
J. Shi ◽  
J. T. Boyle
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessel ◽  
Limit Load ◽  
Analysis Procedure ◽  
Element Analysis ◽  
Elastic Continuum ◽  
Limit Loads ◽  
Simple Bounds ◽  
Elastic Compensation Method

A method for bounding limit loads by an iterative elastic continuum finite element analysis procedure, referred to as the elastic compensation method, is proposed. A number of sample problems are considered, based on both exact solutions and finite element analysis, and it is concluded that the method may be used to obtain limit-load bounds for pressure vessel design by analysis applications with useful accuracy.

scholarly journals Numerical Limit Load Analysis of 3D Pressure Vessel with Volume Defect Considering Creep Damage Behavior

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xianhe Du ◽  
Donghuan Liu ◽  
Yinghua Liu
Keyword(s):  
High Temperature ◽  
Pressure Vessel ◽  
Creep Damage ◽  
Limit Load ◽  
Numerical Approach ◽  
Pressure Vessels ◽  
Load Carrying ◽  
Vessel Structure ◽  
Damage Law ◽  
Volume Defect

The limit load of 3D 2.25Cr-1Mo steel pressure vessel structures with volume defect at 873 K is numerically investigated in the present paper, and limit load under high temperature is defined as the load-carrying capacity after the structure serviced for a certain time. The Norton creep behavior with Kachanov-Robotnov damage law is implemented in ABAQUS with CREEP subroutine and USDFLD subroutine. Effect of dwell time to the material degradation of 2.25Cr-1Mo steel has been considered in this paper. 190 examples for the different sizes of volume defects of pressure vessels have been calculated. Numerical results showed the feasibility of the present numerical approach. It is found that the failure mode of the pressure vessel depends on the size of the volume defect and the service life of the pressure vessel structure at high temperature depends on the defect ratio seriously.

The Effects of the Distance Between Two Defects on the Load-Carrying Capacity of a Pressure Vessel

1999 ◽  
Vol 122 (2) ◽  
pp. 198-203
Author(s):  
H. F. Chen ◽  
D. W. Shu
Keyword(s):  
Numerical Method ◽  
Curve Fitting ◽  
Upper Bound ◽  
Carrying Capacity ◽  
Pressure Vessel ◽  
Empirical Formula ◽  
Pressure Vessels ◽  
Load Carrying Capacity ◽  
Single Defect ◽  
Load Carrying

A simplified numerical method for both lower and upper-bound limit analyses of 3-D structure has been developed in our previous work. The load-carrying capacities of 3-D pipelines with either one or two part-through defects of various geometrical configurations were calculated by the proposed method. In the present paper, the effects of the distance between two defects on the load-carrying capacity of pressure vessels are evaluated and discussed in details. Using curve-fitting schemes, an empirical formula for obtaining the load-carrying capacity of pressure vessels with double defects from that of pressure vessels with a single defect are proposed. Some engineering suggestions are presented simultaneously. All the numerical results confirm the applicability of the simplified numerical method. [S0094-9930(00)00102-5]

Variational Method for Limit Load Analysis of Inhomogeneous Media

2009 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Carrying Capacity ◽  
Material Properties ◽  
Three Dimensional ◽  
Limit Load ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Strain Fields ◽  
Adjustment Procedure ◽  
Load Carrying ◽  
Load Analysis

The load carrying capacity of a body with varying material properties (inhomogeneous) is investigated using the various lower and upper bound limit load multipliers in the context of varational principles originally proposed by Mura and co-workers. In order to evaluate the different limit load multipliers, Elastic Modulus Adjustment Procedure (EMAP) is used to obtain statically admissible stress and kinemattically admissible strain fields at a limit load stage. The proposed upper and lower bound limit load solutions are compared with the results obtained from inelastic finite element analysis (FEA) for several examples with two-dimensional and three-dimensional geometries.

Variational and Classical Methods for Limit Load Analysis of Inhomogeneous Media

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Carrying Capacity ◽  
Variational Principles ◽  
Three Dimensional ◽  
Limit Load ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Strain Fields ◽  
Adjustment Procedure ◽  
Load Carrying ◽  
Load Analysis

The load carrying capacity of a component or structure with varying material properties (inhomogeneous) is investigated using various lower- and upper-bound limit load multipliers in the context of variational principles. In order to evaluate the different limit load multipliers, the elastic modulus adjustment procedure is used to obtain statically admissible stress and kinematically admissible strain fields. The proposed upper and lower bound limit load estimates are compared with the results obtained from inelastic finite element analysis for two- and three-dimensional geometries.

A Study on Fatigue Life Evaluation of Pressure Vessel Made of ASME SA240-316L Material Using Numerical Analysis

2019 ◽  
Vol 893 ◽  
pp. 1-5 ◽  
Author(s):  
Eui Soo Kim
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Pressure Vessel ◽  
Life Prediction ◽  
Pressure Vessels ◽  
Physical Damage ◽  
Element Analysis ◽  
Internal Damage ◽  
Life Evaluation ◽  
Fatigue Life Evaluation

Pressure vessels are subjected to repeated loads during use and charging, which can causefine physical damage even in the elastic region. If the load is repeated under stress conditions belowthe yield strength, internal damage accumulates. Fatigue life evaluation of the structure of thepressure vessel using finite element analysis (FEA) is used to evaluate the life cycle of the structuraldesign based on finite element method (FEM) technology. This technique is more advanced thanfatigue life prediction that uses relational equations. This study describes fatigue analysis to predictthe fatigue life of a pressure vessel using stress data obtained from FEA. The life prediction results areuseful for improving the component design at a very early development stage. The fatigue life of thepressure vessel is calculated for each node on the model, and cumulative damage theory is used tocalculate the fatigue life. Then, the fatigue life is calculated from this information using the FEanalysis software ADINA and the fatigue life calculation program WINLIFE.

DESIGN AND ANALYSIS OF AN INTEGRATED THREE- BAY THERMOPLASTIC COMPOSITE WINGBOX

2021 ◽  
Author(s):  
VINCENZO OLIVERI ◽  
GIOVANNI ZUCCO ◽  
MOHAMMAD ROUHI ◽  
ENZO COSENTINO ◽  
RONAN O’HIGGINS ◽  
...  
Keyword(s):  
Variable Stiffness ◽  
Thermoplastic Composite ◽  
High Fidelity ◽  
Material System ◽  
Load Carrying Capacity ◽  
Element Analysis ◽  
Single Piece ◽  
Load Carrying ◽  
Post Buckling ◽  
Composite Material System

The design of a multi-part aerospace structural component, such as a wingbox, is a challenging process because of the complexity arising from assembly and integration, and their associated limitations and considerations. In this study, a design process of a stiffeners-integrated variable stiffness three-bay wingbox is presented. The wingbox has been designed for a prescribed buckling and post-buckling performance (a prescribed real testing scenario) and made from thermoplastic composite material system (Carbon-PEEK) with the total length of three meters. The stiffeners and spars are integrated into the top and bottom panels of the wingbox resulting a single-piece blended structure with no fasteners or joints. The bottom skin also has an elliptical cut-out for access purposes. The composite tows are steered around this cutout for strain concentration reduction purposes. The fiber/tow steering in the top skin bays (compression side) has also been considered for improved compression-induced buckling load carrying capacity. The proposed design has been virtually verified via high fidelity finite element analysis.

Development of Z-Factor for Circumferential Part-Through Surface Cracks in Dissimilar Metal Welds

2008 ◽  
Author(s):  
D.-J. Shim ◽  
G. M. Wilkowski ◽  
D. L. Rudland ◽  
F. W. Brust ◽  
Kazuo Ogawa
Keyword(s):  
Correction Factor ◽  
Carrying Capacity ◽  
Limit Load ◽  
Maximum Load ◽  
Load Carrying Capacity ◽  
Surface Cracks ◽  
Crack Driving Force ◽  
Dissimilar Metal ◽  
Load Carrying ◽  
J Estimation

Section XI of the ASME Code allows the users to conduct flaw evaluation analyses by using limit-load equations with a simple correction factor to account elastic-plastic fracture conditions. This correction factor is called a Z-factor, and is simply the ratio of the limit-load to elastic-plastic fracture mechanics (EPFM) maximum-load predictions for a flaw in a pipe. The past ASME Section XI Z-factors were based on a circumferential through-wall crack in a pipe rather than a surface crack. Past analyses and pipe tests with circumferential through-wall cracks in monolithic welds showed that the simplified EPFM analyses (called J-estimation schemes) could give good predictions by using the toughness, i.e., J-R curve, of the weld metal and the strength of the base metal. The determination of the Z-factor for a dissimilar metal weld (DMW) is more complicated because of the different strength base metals on either side of the weld. This strength difference can affect the maximum load-carrying capacity of the flawed pipe by more than the weld toughness. Recent work by the authors for circumferential through-wall cracks in DMWs has shown that an equivalent stress-strain curve is needed in order for the typical J-estimation schemes to correctly predict the load carrying capacity in a cracked DMW. In this paper, the Z-factors for circumferential surface cracks in DMW were determined. For this purpose, a material property correction factor was determined by comparing the crack driving force calculated from the J-estimation schemes to detailed finite element (FE) analyses. The effect of crack size and pipe geometry on the material correction factor was investigated. Using the determined crack-driving force and the appropriate toughness of the weld metal, the Z-factors were calculated for various crack sizes and pipe geometries. In these calculations, a ‘reference’ limit-load was determined by using the lower strength base metal flow stress. Furthermore, the effect of J-R curve on the Z-factor was investigated. Finally, the Z-factors developed in the present work were compared to those developed earlier for through-wall cracks in DMWs.

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