Collapse of Imperfect Tubulars

1986 ◽  
Vol 108 (3) ◽  
pp. 214-220
Author(s):  
P. D. Pattillo ◽  
N. C. Huang
Keyword(s):  
Axial Load ◽  
Nonlinear Response ◽  
External Pressure ◽  
Cross Sectional ◽  
Collapse Resistance ◽  
The Cross ◽  
Eventual Collapse

The nonlinear response and eventual collapse of a cylinder loaded by resultant external pressure and axial load is analyzed. The cross-sectional description of the cylinder is sufficiently general to include ovality, eccentricity, and local thickness anomalies. Applications of the model include the prediction of minimum collapse resistance of commercial tubulars.

The Effect of Length: Diameter Ratio on Collapse of Casing

1984 ◽  
Vol 106 (2) ◽  
pp. 160-165 ◽  
Author(s):  
N. C. Huang ◽  
P. D. Pattillo
Keyword(s):  
Axial Load ◽  
External Pressure ◽  
Field Application ◽  
Diameter Ratio ◽  
Finite Cylinder ◽  
Oil Well ◽  
Steel Mill ◽  
Cross Sectional ◽  
Axial Tension ◽  
Collapse Resistance

This paper presents an analysis of the cross-sectional collapse of a cylinder of finite length loaded simultaneously by an axial tension (which may be zero) and external pressure. The calculation is based on Sanders’ nonlinear shell equations with plasticity introduced via the concept of effective stress from a uniaxial tension test. The finite cylinder is an appropriate model of oil well casing as it undergoes quality control testing in the steel mill where the edges of the cylinder are usually fixed in the case of nonzero axial load and free in the case of zero axial load. However, in field application, the length: diameter ratio of casing is such that the cylinder may be considered infinite. Guidelines contained herein permit prediction of the collapse resistance of field casing from the results of mill tests performed on short samples.

Collapse of Oil Well Casing With Ovality

1985 ◽  
Vol 107 (1) ◽  
pp. 128-134 ◽  
Author(s):  
P. D. Pattillo ◽  
N. C. Huang
Keyword(s):  
Nonlinear Response ◽  
External Pressure ◽  
Oil Well ◽  
Infinite Length ◽  
Service Environment ◽  
Collapse Resistance ◽  
Eventual Collapse ◽  
Design Calculations ◽  
Model Oil ◽  
Interesting Alternative

The nonlinear response and eventual collapse of an initially imperfect cross section of a cylinder of infinite length is analyzed. The cylinder is loaded by external pressure and axial load and is intended to model oil well casing in a service environment. Results from the analysis agree well with experimental data and provide an interesting alternative to current empirical/statistical methods for determining the minimum collapse resistance of casing for use in design calculations.

Collapse of Thin-Walled Elliptical Tubes for High Values of Major-to-Minor Axis Ratio

1993 ◽  
Vol 115 (4A) ◽  
pp. 432-440 ◽  
Author(s):  
C. Ribreau ◽  
S. Naili ◽  
M. Bonis ◽  
A. Langlet
Keyword(s):  
Contact Pressure ◽  
Cross Section ◽  
External Pressure ◽  
Straight Line Segment ◽  
Minor Axis ◽  
Cross Sectional ◽  
Axis Ratio ◽  
Straight Line ◽  
Thin Walled ◽  
The Cross

The topic of this study concerns principally representative models of some elliptical thin-walled anatomic vessels and polymeric tubes under uniform negative transmural pressure p (internal pressure minus external pressure). The ellipse’s ellipticity ko, defined as the major-to-minor axis ratio, varies from 1 up to 10. As p decreases from zero, at first the cross-section becomes somewhat oval, then the opposite sides touch in one point at the first-contact pressure pc. If p is lowered beneath pc, the curvature of the cross-section at the point of contact decreases until it becomes zero at the osculation pressure or the first line-contact pressure p1. For p<p1, the contact occurs along a straight-line segment, the length of which increases as p decreases. The pressures pc and p1 are determined numerically for various values of the wall thickness of the tubes. The nature of contact is especially described. The solution of the related nonlinear, two-boundary-values problem is compared with previous experimental results which give the luminal cross-sectional area (from two tubes), and the area of the mid-cross-section (from a third tube).

Electro-thermal-mechanical Coupled Analysis on Two High-Current Composite Umbilical Cable Cross-sections

2021 ◽  
pp. 1-32
Author(s):  
Jun Yan ◽  
Qi Su ◽  
Yufeng Bu ◽  
Zhixun Yang ◽  
Qingzhen Lu ◽  
...  
Keyword(s):  
Cross Sections ◽  
Heat Dissipation ◽  
Production Systems ◽  
Mechanical Analysis ◽  
External Pressure ◽  
Field Analysis ◽  
Coupled Analysis ◽  
Cross Sectional ◽  
The Cross ◽  
Umbilical Cable

Abstract A new type of umbilical cable named ‘strong-electricity composite umbilical cable’ is composed of electronic cables, optical cables, steel tubes and structural strengthening components. It can be regarded as a key piece of industrial equipment in subsea production systems that provide control functions, strong electric and hydraulic remote transmission. when it is oriented at a power supply with a relatively high rated voltage, power transmission will produce a lot of heat. Then, the cross-sectional temperature increases, which affects the performances of its material and mechanical responses. Therefore, electro–thermal–mechanical coupled analysis is critical for the cross-sectional design of the strong-electricity composite umbilical cable. Accordingly, a multi-physics coupled analysis was performed based on two typical umbilical cable cross-sections. Finite element models were established and subjected to electro–thermal analysis to obtain a temperature distribution of the two sections at different current capacities. Based on results of temperature field analysis, the section models were subjected to thermal–mechanical analysis. The results of the two types of analyses are compared and differences are discussed, which illustrate the multi-physics coupled effect cannot be neglected. The armored layers will relatively reduce the heat dissipation performance, but compared with the umbilical cable model without the armored layers, the model with double-armored layers is less affected by temperature, so its capacity of resistance external pressure is relatively better. The proposed coupled analysis methodology provides a new guidance for the design of the strong-electricity composite umbilical cables.

Explicit Solutions for the Stability of No-Tension Beam-Columns

2003 ◽  
Vol 03 (02) ◽  
pp. 195-213 ◽  
Author(s):  
A. de Falco ◽  
M. Lucchesi
Keyword(s):  
Differential Equations ◽  
Cross Section ◽  
Axial Load ◽  
Explicit Solutions ◽  
Cross Sectional ◽  
Beam Columns ◽  
The Cross ◽  
The Stability ◽  
No Tension Material ◽  
Explicit Relation

This work concerns the stability of rectangular cross-sectional piles made of a no-tension material and subjected to an axial load acting at the extremities within the middle third of the cross section. The resulting differential equations are solved, and an explicit relation between the load and a suitable deformability parameter obtained.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

A Technique for Measuring the Cross-Sectional Axes of the Longissimus Dorsi Muscle and Fat Depth in Lambs1,2

1960 ◽  
Vol 19 (3) ◽  
pp. 803-809
Author(s):  
D. J. Matthews ◽  
R. A. Merkel ◽  
J. D. Wheat ◽  
R. F. Cox
Keyword(s):  
Longissimus Dorsi ◽  
Cross Sectional ◽  
Longissimus Dorsi Muscle ◽  
Dorsi Muscle ◽  
The Cross

Automated Diagonal Slice and View Solution for 3D Device Structure Analysis

2018 ◽  
Author(s):  
Sang Hoon Lee ◽  
Jeff Blackwood ◽  
Stacey Stone ◽  
Michael Schmidt ◽  
Mark Williamson ◽  
...  
Keyword(s):  
Cross Section ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Image Data ◽  
Planar Surface ◽  
Device Structure ◽  
Cross Sectional ◽  
Device Structures ◽  
The Cross ◽  
Planar Analysis

Abstract The cross-sectional and planar analysis of current generation 3D device structures can be analyzed using a single Focused Ion Beam (FIB) mill. This is achieved using a diagonal milling technique that exposes a multilayer planar surface as well as the cross-section. this provides image data allowing for an efficient method to monitor the fabrication process and find device design errors. This process saves tremendous sample-to-data time, decreasing it from days to hours while still providing precise defect and structure data.

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