Viscoelastic deformation of a thick-walled tube acted on by external pressure and axial tension

1968 ◽  
Vol 4 (4) ◽  
pp. 327-335 ◽  
Author(s):  
V. M. Zhigalkin
Keyword(s):  
External Pressure ◽  
Viscoelastic Deformation ◽  
Axial Tension

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.

A testing rig for cycling at high biaxial strains

1973 ◽  
Vol 8 (3) ◽  
pp. 168-175 ◽  
Author(s):  
J M H Andrews ◽  
E G Ellison
Keyword(s):  
High Strain ◽  
External Pressure ◽  
Multiaxial Fatigue ◽  
Axial Tension ◽  
Wide Range ◽  
Fatigue Data ◽  
Other Information ◽  
Tension And Compression ◽  
Tubular Specimens ◽  
Experimental Rig

There is a scarcity of multiaxial fatigue data available to designers especially in the high-strain régime. This is due in part of the complexity of the test equipment involved. A servo-hydraulic experimental rig has been developed for the application of biaxial high-strain reversed cycles to thin-walled tubular specimens, i.e. under axial tension and compression and internal and external pressure. It is capable of testing over a wide range of strain ratios and is reasonably versatile in that other information pertaining to buckling, Poisson's ratio, and criteria for yielding can be obtained.

The research on the different loading paths of pipes under combined external pressure and axial tension

2019 ◽  
Vol 160 ◽  
pp. 219-228 ◽  
Author(s):  
Jian-xing Yu ◽  
Meng-xue Han ◽  
Jing-hui Duan ◽  
Yang Yu ◽  
Hua-kun Wang
Keyword(s):  
External Pressure ◽  
Loading Paths ◽  
Axial Tension

Assessment of Design Collapse Equations for OCTG Pipes Under Combined Loads

2021 ◽  
Author(s):  
Eduardo Felipe Pereira da Silva ◽  
Theodoro Antoun Netto
Keyword(s):  
Numerical Model ◽  
Work Group ◽  
Experimental Tests ◽  
External Pressure ◽  
Combined Loading ◽  
Current Standard ◽  
Combined Loads ◽  
Axial Tension ◽  
Rating Method ◽  
Different Diameters

Abstract The objective of this paper is to evaluate the design collapse equations presented in chapter 8 and Annex F of the current standard ISO TR 10400 for casings under external pressure and axial tension. A nonlinear numerical model has been developed to analyze the performance of these equations to predict casing collapse under combined loads. Experimental tests have been performed with different diameters, d/h ratio and steel grade to calibrate the numerical model. The KT model has been assessed previously against different models by API Work Group and it has shown to be reliable to be used as design equations. However, the API Work Group included the KT model in the appendix F of the code as informative. The work done in this paper has confirmed the better performance of KT model for most of the cases analyzed. For combined loading, the API collapse equation results in a simple strength de-rating method, whilst the KT model has achieved similar behavior for low values of axial tension when comparing the experimental results. The axial tension for the casings into the well is likely to be lower than 40% of yield strength. Therefore, the KT model has shown to be more convenient to well design than API equations.

Experimental Study on the Effect of Axial Tension Load on the Collapse Strength of Oilwell Casing

1982 ◽  
Vol 22 (05) ◽  
pp. 609-615 ◽  
Author(s):  
T. Kyogoku ◽  
K. Tokimasa ◽  
H. Nakanishi ◽  
T. Okazawa
Keyword(s):  
Experimental Data ◽  
Theoretical Analysis ◽  
Testing Machine ◽  
External Pressure ◽  
Tension Stress ◽  
Plastic Collapse ◽  
Collapse Pressure ◽  
Axial Tension ◽  
Collapse Strength ◽  
Tension Load

Abstract This paper discusses a newly developed collapse testing machine that permits investigation of practical performances of oilwell casings. Although a theoretical performances of oilwell casings. Although a theoretical analysis has shown that "axial tension stress has no effect on collapse pressure in the elastic case," this theory is not applied to the design of casing string because of lack of useful experimental data or authorized recommendation. To investigate the effect of axial tension load, full-size commercial casings have been tested under combined loading of axial tension load and external pressure. From the experimental results, the theory mentioned was proved in the case of so-called high-collapse casing, which has been used widely in recent years. Also shown is the applicable d/h range, which is wider than API's elastic collapse range. If the results of this experiment were applied to the design of a casing program, an economical and safe one could be obtained. program, an economical and safe one could be obtained. Introduction Recently, improved drilling techniques have permitted deeper and deeper oil and gas wells. As well depth increases, steel pipes for well casings receive greater external pressure and axial tension load because of the weight of the casing string. High-collapse casing, which has higher collapse strength per unit weight, has become easily available. To select and to design casing for such wells properly and economically, estimating collapse strength of the casing under axial tension load is very important. Much research and many experiments concerning collapse problems on casing, drillpipe, and tubing has been conducted by 1939. A theoretical analysis showed that axial tension stress lowers the collapse pressure in the case of plastic collapse and that axial tension stress has no effect on collapse pressure in the elastic case. Although collapse tests under axial tension load simulating oilwell casing in service were conducted on 2-in.-OD tubings, the theory for the effect of axial tension stress in the elastic collapse had not been proved sufficiently. There are few published experimental proved sufficiently. There are few published experimental data on collapse strength under axial tension load. In 1968, API summarized the collapse data and showed the formulas for collapse pressure and for collapse pressure under axial tension stress in the case of plastic collapse. The purpose of our study is to show how the collapse strength of commercial casings with large OD's behaves under the axial tension load, especially in the case of elastic collapse. To test the large-size casings, a multipurpose collapse testing machine that can simulate the service condition of oilwell casing has been developed. Statement of the Problem The collapse strength of casings under combined external pressure and axial tension load may be calculated from pressure and axial tension load may be calculated from Ref. 6's Formula 1.1.5.1: ....................(1) SPEJ p. 609

On the Collapse of Offshore Pipelines under External Pressure and Axial Force

2013 ◽  
Vol 419 ◽  
pp. 134-139
Author(s):  
Neng Gan ◽  
Jiang Hong Xue
Keyword(s):  
Hydrostatic Pressure ◽  
Axial Force ◽  
Analytical Approach ◽  
Shell Theory ◽  
Ritz Method ◽  
Morphological Characteristics ◽  
External Pressure ◽  
Governing Equations ◽  
Offshore Pipelines ◽  
Axial Tension

The elastic collapse of long cylinders under combined external pressure and axial force was investigated using analytical approach. Long cylindrical pipelines laid on the seabed are subjected to external pressure, initial defect will cause the local collapse of the pipelines. Due to the change of subsea environments and construction conditions, circular pipelines are subjected not only to the hydrostatic pressure, but also to forces of other forms, such as axial tension or compression, so on and so forth. This paper studies the local collapse and the morphological characteristics of a circular pipelines subjected to hydrostatic pressure and axial force. Governing equations based on Karman-Donnell`s shell theory are derived and are solved using Ritz method.

Collapse of Oil Well Casing

1982 ◽  
Vol 104 (1) ◽  
pp. 36-41 ◽  
Author(s):  
N. C. Huang ◽  
P. D. Pattillo
Keyword(s):  
External Pressure ◽  
Critical Conditions ◽  
Oil Well ◽  
Infinite Length ◽  
Empirical Formulas ◽  
Plastic Buckling ◽  
Incremental Theory ◽  
Axial Tension ◽  
Strain Formulation ◽  
Theoretical Results

This paper is concerned with the theoretical study of the collapse of oil well casing under various loading conditions. The analysis is based on a model of a cylindrical shell of infinite length subjected to an axial tension and an external pressure. It is found that when the thickness-radius ratio of the casing is sufficiently small, collapse of the casing may take place in a form of plastic buckling. Critical conditions for plastic buckling are derived based on the J2-incremental theory and the J2-deformation theory. Another type of collapse is caused by the realization of the ultimate strength of the material. Critical conditions in the second case of collapse are calculated based on a plane strain formulation associated with the J2-incremental theory. The theoretical results obtained in this paper correspond well with empirical formulas developed earlier by the API for the design of oil well casing.

On the Collapse of Long, Thick-Walled Tubes Under External Pressure and Axial Tension

1993 ◽  
Vol 115 (1) ◽  
pp. 15-26 ◽  
Author(s):  
R. Madhavan ◽  
C. D. Babcock ◽  
J. Singer
Keyword(s):  
Strain Curve ◽  
External Pressure ◽  
Combined Loading ◽  
Flow Rule ◽  
Two Dimensional ◽  
Stress Strain Curve ◽  
Axial Tension ◽  
Collapse Strength ◽  
Tension Loading ◽  
Good Agreement

The paper presents the results from a combined experimental and analytic study on the collapse of long, thick-walled tubes subjected to external pressure and axial tension. The experiments involved tubes of diameter-to-thickness ratio (Dm/t) 10 to 40. Collapse envelopes were obtained for two different pressure-tension loading paths. Collapse tests involving initially ovalized tubes were also carried out. The collapse strength predicted with a two-dimensional elasto-plastic model applying J2 flow rule was in good agreement with the experiments. The results show that the collapse strength under combined loading is strongly influenced by initial ovality and that the shape of the stress-strain curve has a significant influence on the tension-pressure collapse envelope.

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