scholarly journals Nonlinear Buckling Finite Element Analysis to Estimate Collapse Pressure of Thick Cylinder under Hydrostatic Pressure

2019 ◽  
Vol 33 (3) ◽  
pp. 272-279 ◽  
Author(s):  
Jae-Hwan Lee ◽  
Byoungjae Park ◽  
Hyuek-Jin Choi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Hydrostatic Pressure ◽  
Element Analysis ◽  
Nonlinear Buckling ◽  
Collapse Pressure ◽  
Thick Cylinder

Solutions for Non-Newtonian Flow Into Elliptical Openings

1991 ◽  
Vol 58 (3) ◽  
pp. 820-824 ◽  
Author(s):  
A. Bogobowicz ◽  
L. Rothenburg ◽  
M. B. Dusseault
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Steady State ◽  
Hydrostatic Pressure ◽  
Velocity Field ◽  
Velocity Fields ◽  
Newtonian Flow ◽  
Element Analysis ◽  
Elliptical Opening ◽  
Elliptical Coordinates

A semi-analytical solution for plane velocity fields describing steady-state incompressible flow of nonlinearly viscous fluid into an elliptical opening is presented. The flow is driven by hydrostatic pressure applied at infinity. The solution is obtained by minimizing the rate of energy dissipation on a sufficiently flexible incompressible velocity field in elliptical coordinates. The medium is described by a power creep law and solutions are obtained for a range of exponents and ellipse eccentricites. The obtained solutions compare favorably with results of finite element analysis.

Buckling and layer failure of composite laminated cylinders subjected to hydrostatic pressure

2017 ◽  
Vol 24 (3) ◽  
pp. 415-422 ◽  
Author(s):  
Ke Chun Shen ◽  
Guang Pan ◽  
JiangFeng Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Hydrostatic Pressure ◽  
Failure Criteria ◽  
Underwater Vehicle ◽  
Element Analysis ◽  
Finite Element Program ◽  
Failure Characteristics ◽  
Element Program ◽  
Critical Buckling Pressure

AbstractThe buckling and layer failure characteristics of composite laminated cylinders subjected to hydrostatic pressure were investigated through finite element analysis for underwater vehicle application. The Tsai-Wu failure criteria were used as the failure criteria for the buckling analysis. A sensitivity analysis was conducted to research the influence of the number of elements on the critical buckling pressure. ANSYS, a finite element program, successfully predicted the buckling pressure with 5.3–27.8% (linear) and 0.3–22.5% (nonlinear) deviation from experimental results. The analysis results showed that the cylinders can carry more pressure after a slight decrease in pressure and recovery of the supporting load. For layer failure analysis, it was found that the failure that occurred in the 0° layer was more serious than that in the 90° layer within the neighboring layers at the inner layers (nos. 1–7) and outer layers (nos. 8–24).

Damage Evaluation of Grade 91 Thick Cylinder Under Variable Thermal Cyclic Loading Using Continuum Damage Coupled Viscoplastic Models

2019 ◽  
Author(s):  
Nazrul Islam ◽  
Tasnim Hassan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Temperature ◽  
Creep Deformation ◽  
Continuum Damage ◽  
Element Analysis ◽  
Energy Agency ◽  
Creep Fatigue ◽  
Thick Cylinder ◽  
Grade 91

Abstract This study evaluates creep-fatigue damage in the modified Grade 91 thick-cylinder tested by Japan Atomic Energy Agency (JAEA), to understand the failure mechanism of critical components of Fast Reactor nuclear plants. As modified Grade 91 demonstrated creep-fatigue interaction induced failure mechanisms, finite element analysis of high-temperature components will require a unified constitutive model (UCM) that can simulate various creep-fatigue responses with reasonable accuracy. Hence, a UCM coupled with various advanced modeling features including the continuum damage modeling features is investigated to demonstrate their predictability of the fatigue, creep and creep-fatigue responses of the modified Grade 91 steel. The modified UCM is implemented into ABAQUS for analysis of creep deformation in the thick cylinder benchmark problem. Finite element analysis results are presented to demonstrate how the thermal cycling influences the creep-deformation of this high-temperature component. It is also demonstrated how thermal cycling’s influence on fatigue life can be determined based on the damage variable incorporated in the UCM.

Estimating Collapse Pressure of Centralizer Subs From Machine Learning Models

2019 ◽  
Author(s):  
Ishita Chakraborty
Keyword(s):  
Machine Learning ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Regression Model ◽  
Learning Models ◽  
Element Analysis ◽  
Collapse Pressure ◽  
Geometrical Features ◽  
Past Data ◽  
Machine Learning Models

Abstract Centralizer subs are run in conjunction with the casing strings in the oil/gas wells to ensure that the casing is centralized while it is installed down hole. Centralizer subs are fabricated of stronger material than the casing strings and designed such that it can sustain a higher collapse pressure than the attached tubing string. A typical centralizer sub is a tube with some complex geometrical features, so the collapse pressure of a centralizer sub can only be estimated by conducting a finite element analysis or subjecting it to a collapse pressure test. Both the options are time consuming and expensive. In this work, a machine learning based regression model is used to derive a parametric equation for calculating the collapse pressure of a centralizer sub. The data needed to train and cross validate the regression model is obtained from finite element analysis (FEA). This machine learning based equation provides a closer estimate of the collapse pressure of the centralizer subs to the results obtained from the FEA than the existing collapse prediction equations from API RP 1111. This machine learning based estimation of collapse pressure will help in correctly predicting the collapse rating of the centralizer sub without performing FEA or testing for each individual subs. This approach of building machine learning models from data generated from FEA can be used for analysis of other equipment as well. With the availability of past data collected/generated through years, the recent advances in machine learning can be used to save time and resources.

A Study of Jones’ Equation for Buckling of Laminated Composite Cylinders Under External Hydrostatic Pressure

1993 ◽  
Vol 37 (03) ◽  
pp. 239-252
Author(s):  
Thomas Perry ◽  
Zan Miller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Materials ◽  
Hydrostatic Pressure ◽  
Analytical Solution ◽  
Laminated Composite ◽  
External Hydrostatic Pressure ◽  
Element Analysis ◽  
Composite Cylinders ◽  
Good Agreement

A classical solution derived by Jones (1968) is used to evaluate the buckling performance of unstiffened generally orthotropic and quasi-isotropic laminated Graphite/Epoxy (GREP) composite cylinders subjected to external hydrostatic pressure. The results of the analysis are compared to finite-element analysis results. Hydrostatic testing to failure of several 12-ply T300/5208 GREP cylinders demonstrated that the classical buckling solution is quite accurate. The finite-element results showed good agreement with both Jones' solution and test data, with several notable exceptions. Evaluation of strain gage data via Southwell's (1932) method indicates that the test cylinders were fabricated very nearly true. A postiori buckling predictions using Southwell plots all compared quite favorably with the Jones' equation predictions. This work demonstrates that a relatively simple analytical solution can reliably evaluate the performance of composite materials in pressure hull applications.

Nonlinear Buckling Finite Element Analysis of Stiffened Steel Plates

2013 ◽  
Vol 699 ◽  
pp. 450-456 ◽  
Author(s):  
E. Gunay ◽  
C. Aygun ◽  
Y. O. Yıldız
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Loading ◽  
Steel Plates ◽  
Element Analysis ◽  
Nonlinear Buckling ◽  
Compressive Stresses ◽  
Out Of Plane ◽  
Global Buckling ◽  
Stiffened Steel

In this paper, thin rectangular steel plates with stiffeners are examined under compressive loading. Consequently, nonlinear buckling finite element analysis (FEA) solutions are obtained by using ANSYS®. The local and global buckling patterns of stiffened steel plate geometries with simply supported boundary conditions are generated and critical buckling stresses are studied. Geometrically nonlinear buckling analyses are compared in order to evaluate the distributions of compressive stresses versus in-plane contractions and compressive stresses versus out-of plane deflections. Hence, it is concluded that there are critical load intervals. It is also observed that for critical loads, segments between stiffeners may switch from stable to unstable configurations under compressive stresses.

Elastic-Plastic Solutions for Open-End Thick Walled Cylinders Subjected to Internal and External Pressures

2008 ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Yield Criterion ◽  
External Pressure ◽  
Plastic Collapse ◽  
Elastic Instability ◽  
Element Analysis ◽  
Collapse Pressure ◽  
Elastic Plastic ◽  
External Pressures

Available theoretical solutions for the collapse pressure of open-end thick walled cylinders based on the Vo n Misses yield criterion are very limited. The known elastic-plastic theoretical solutions are primarily based on the Tresca yield criterion. So far, little study has been devoted to fairly thick open-end cylinders under external pressure. This can be performed by finite element analysis that considers material plasticity. In this paper the authors propose the use of simple formulae for the solution of the collapse internal and external pressures of open-end cylinders. The proposed formulae provide excellent agreement with finite element results obtained by the authors. Also criterion is provided for the interaction of elastic instability and plastic collapse of open-end cylinders subjected to external pressure.

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