scholarly journals Elasto-Plastic Finite Element Analysis of Imperfect Spherical Shells Subject to External Pressure

1982 ◽  
Vol 1982 (151) ◽  
pp. 197-207 ◽  
Author(s):  
Wataru Yasukawa ◽  
Hazime Kawakami ◽  
Takao Yoshikawa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
External Pressure ◽  
Spherical Shells ◽  
Element Analysis

Fitness for Service Assessments of Bulging and Out-of-Round Structures

2004 ◽  
Author(s):  
Peter Carter ◽  
D. L. Marriott ◽  
M. J. Swindeman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Structural Model ◽  
External Pressure ◽  
Element Analysis ◽  
Structural Imperfection ◽  
Level 2

This paper examines techniques for the evaluation of two kinds of structural imperfection, namely bulging subject to internal pressure, and out-of-round imperfections subject to external pressure, with and without creep. Comparisons between comprehensive finite element analysis and API 579 Level 2 techniques are made. It is recommended that structural, as opposed to material, failures such as these should be assessed with a structural model that explicitly represents the defect.

Finite Element Analysis for the Stiffness and the Buckling of Corrugated Tubes in Heat Exchanger

2012 ◽  
Vol 468-471 ◽  
pp. 1675-1680 ◽  
Author(s):  
Xiao Jing Wang ◽  
Zhi Min Wang ◽  
Nian Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stability Analysis ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
External Pressure ◽  
Element Analysis ◽  
Value Analysis ◽  
Compressive Pressure ◽  
The Stability

Corrugated tubes in a heat exchanger are analyzed by using the FEA methods. And the formula how to compute single wave’s rigidity is obtained. Besides, methods of analyzing the stability of corrugated tubes under internal compressive pressure and external pressure are proposed which include characteristic value analysis and non-linear stability analysis, thus providing theory basis for the stability research of heat exchangers.

scholarly journals Study on the characteristics of pipe buckling strength under pure bending and external stress using nonlinear finite element analysis

2021 ◽  
Vol 12 (2) ◽  
pp. 110-116
Author(s):  
Hartono Yudo ◽  
Wilma Amiruddin ◽  
Ari Wibawa Budi Santosa ◽  
Ocid Mursid ◽  
Tri Admono
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bending Moment ◽  
Nonlinear Finite Element Analysis ◽  
External Pressure ◽  
Diameter Ratio ◽  
Nonlinear Finite Element ◽  
Pure Bending ◽  
Element Analysis ◽  
Buckling Strength

Buckling and collapse are important failure modes for laying and operating conditions in a subsea position. The pipe will be subjected to various kinds of loads, i.e., bending moment, external pressure, and tension. Nonlinear finite element analysis was used to analyze the buckling strength of the pipe under pure bending and external pressure. The buckling of elastic and elasto-plastic materials was also studied in this work. The buckling strength due to external pressure had decreased and become constant on the long pipe when the length-to-diameter ratio (L/D) was increased. The non-dimensional parameter (β), which is proportionate to (D/t) (σy/E), is used to study the yielding influence on the buckling strength of pipe under combined bending and external pressure loading. The interaction curves of the buckling strength of pipe were obtained, with various the diameter-to-thickness ratio (D/t) under combination loads of external pressure and bending moment. For straight pipes L/D = 2.5 to 40, D = 1000 to 4000 mm, and D/t = 50 to 200 were set. The curved pipes D/t = 200, L/D =2.5 to 30 have been investigated by changing the radius of curvature-to-diameter ratio (R/D) from 50 to ∞, for each one. With decreasing R/D, the buckling strength under external pressure decreases slightly. This is in contrast to the bending of a curved pipe. When the value of R/D was decreased, the flexibility of the pipe was increased. However, the buckling strength of the pipe during bending was decreased due to the oval deformation at the cross-section.

Qualification of a Jacketed Vessel Using Finite Element Analysis

2003 ◽  
Author(s):  
Yogeshwar Hari ◽  
Ram Munjal ◽  
Chawki Obeid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessel ◽  
External Pressure ◽  
Element Analysis ◽  
Ring Location ◽  
Section Viii ◽  
Specific Configuration ◽  
Inner Vessel ◽  
Vessel Bottom

The main objective of this paper is to improve a jacketed vessel. The jacketed vessel is usually chosen to heat the contents of the vessel. The chamber or annulus contains fluid under pressure to heat the inner vessel contents. The initial over-all dimensions of the vessel are based on the capacity of the stored liquid. The design was in accordance with the ASME Boiler & Pressure Vessel Code, Section VIII, Div 1. The jacketed vessel bottom head and jacket bottom head are being improved to withstand internal and external design pressures. Bottom head of the jacket can be reinforced in one of the three ways, namely: (1) rings which are radial (these rings also create flow for the fluid); (2) attachment of the rings to the bottom jacket head with stays, since rings cannot be physically welded to the bottom jacket; or (3) there is a possibility, the new bottom head and jacketed head combination can be cast, but that would not be economically feasible. This leads to the following six configurations considered in this paper and they are: (1) internal pressure of 50 psi, (2) external pressure + vacuum pressure of 65 psi, (3) reinforcement with 5 rings with external pressure of 65 psi, (4) rings welded with the bottom jacket head with external pressure of 65 psi, (5) welded with stays on ring location (stay diameter of 1 inch) with external pressure of 65 psi, and (6) welded with stays on ring location (stay diameter of 1.5 inch) with external pressure of 65 psi. The pattern of stays chosen for this analysis is one of uniform distribution on ring locations, which are radially situated. The design dimensions based on Code sizing are used to recalculate the stresses for the jacket vessel. The dimensional jacketed vessel is modeled using STAAD III Finite Element Analysis (FEA) software. The design is found to be safe for the specific configuration considered herein with stays.

Buckling Behavior of General Dome Ends under External Pressure, Using Finite Element Analysis

2011 ◽  
Vol 471-472 ◽  
pp. 833-838 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Major Axis ◽  
External Pressure ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Buckling Behavior ◽  
Ellipse Method ◽  
The Finite Element Analysis ◽  
Critical Buckling Pressure

In this paper, the finite element analysis is used to investigate the effect of shape of dome ends on the buckling of pressure vessel heads under external pressure. The Finite Element Analysis (FEA) with the use of elastic buckling analysis was applied to predict the critical buckling pressure. The influence of geometrical parameters such as thickness, knuckle radius, and the ratio of minor axis to the major axis of dome ends, on the weight and the critical buckling pressure of hemispherical, ellipsoidal, and torispherical dome ends, was studied. The four-centered ellipse method was used to describe the geometry of the dome end.

Cost-Effective Method of Optimization of Stacking Sequences in the Cylindrical Composite Shells Using Genetic Algorithm

2020 ◽  
Author(s):  
Ehsan Daneshkhah ◽  
Reza Jafari Nedoushan ◽  
Davoud Shahgholian ◽  
Nima Sina
Keyword(s):  
Genetic Algorithm ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Tests ◽  
Cost Effective ◽  
Element Model ◽  
External Pressure ◽  
Element Analysis ◽  
Cost Effective Method ◽  
Critical Buckling Pressure

Buckling is one of the common destructive phenomena, which occurs in composite cylinders subjected to external pressure. In this paper, different methods to optimize stacking sequence of these cylinders are investigated. A finite element model is proposed in order to predict critical buckling pressure and the results are validated with previous experimental data. Theoretical analysis based on NASA SP‐8007 solution and the simplified equation for cylinder buckling of ASME RD-1172 are presented and discussed. The results of theoretical and finite element analysis and experimental tests are compared for both glass and carbon epoxy cylinders. Using NASA and ASME formulations, optimal laminations of cylinders in order to maximize buckling pressure, are obtained by genetic algorithm method. Suggested laminations and the values of corresponding critical buckling pressure calculated by finite element analysis, are presented and compared in various states. Obtained results show that while predicted buckling loads of finite element analysis are reliable, NASA formulation can be used in a very cost-effective method to optimize the buckling problems.

Finite Element Analysis and Design of an Annular Tank

2003 ◽  
Author(s):  
Yogeshwar Hari
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Outer Cylinder ◽  
External Pressure ◽  
Seismic Load ◽  
Element Analysis ◽  
Analysis And Design ◽  
Finite Element Software ◽  
Asme Code

The objective of this paper is to design an annular tank. The annular tank is to store various criticality liquids used in today’s industry. The initial over all dimensions of the annular tank are determined from the capacity of the stored liquids. The design function is performed using the ASME Code Sec VIII Div 1. The annular tank design is broken up into (a) outer cylinder, (b) inner cylinder, (c) top cover, and (d) bottom head. It is supported at the bottom. It is anchored at the top. The deflection of the annular space is a critical requirement. Stresses are usually acceptable because the requirement is on the deflection. For vacuum condition the outer cylinder can be treated for external pressure and the inner cylinder can be treated for internal pressure. For internal pressure condition the design pressure consists of working internal pressure plus static head. For this the outer cylinder can be treated for internal pressure and the inner cylinder can be treated for external pressure. The covers are designed for internal pressure at the bottom where the pressure is the maximum. The designed dimensions are used to recalculate the stresses for the annular tank. The dimensioned annular tank is modeled using STAAD III finite element Software. The stresses from the finite element Software are compared to the stresses obtained from recalculated stresses obtained using ASME Code Sec VIII Div 1. The difference in the stress values is explained. This paper’s main objective is to compare the ASME Code to the finite element analysis. The design is found to be safe for the specific configuration considered. In addition the annular tank is checked for temperature and seismic load conditions, which the code does not address.

Stress Analysis and Progressive Failure Analysis of Multilayered Basalt/Epoxy Composites

2015 ◽  
Vol 766-767 ◽  
pp. 21-26 ◽  
Author(s):  
Alexander ◽  
B.S.M. Augustine
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Progressive Failure ◽  
Glass Fibers ◽  
External Pressure ◽  
Basalt Fibers ◽  
Element Analysis ◽  
Progressive Failure Analysis ◽  
Filament Wound

Constructions of pressure vessels like rocket launch vehicles, missiles, rocket propellant tanks, and filament wound pipes for civil and military applications are made out of high strength, high stiffness and light weight composites filaments. Filament winding techniques are used for fabrication of such cylinders and pipes. Many materials like glass fibers, carbon fibers and Kevlar fibers are used due to their good strength when it is subjected to internal pressure as well as external pressure. Basalt fibers are new materials that are fabricated from hard dense basalt rocks. Basalt fibers can be used in the place glass fibers due to their good mechanical behavior when subjected to internal pressure. Plates and beams generally resists bending loads and pipes and tube structures resists internal forces developed through internal and external pressure. This work concentrates the fabrication of filament wound pipes using filament wound techniques and the burst pressure test is carried out. In fuel tanks of rockets, If any one of the layer fails due to internal pressure, there will be mild leakage. For this reason it is mandatory to find out the ply by ply failure. The first ply failure of basalt filament wound pipes subjected to internal pressure is calculated using Finite element analysis. Then the stress and progressive failure analysis was carried out. Maximum stress failure criterion is used for the finite element analysis.

Sign in / Sign up

Export Citation Format

Share Document