Calculation of the pipeline wall thickness under internal pressure at an arbitrary law of hardening

2012 ◽  
Vol 2012 (10) ◽  
pp. 873-878
Author(s):  
S. E. Alexandrov ◽  
R. V. Goldstein
Keyword(s):  
Internal Pressure ◽  
Wall Thickness ◽  
Pipeline Wall

Circumferential Creep Strain of Cylinders Subjected to Internal Pressure: A Comparison of the Theories of Johnson and Bailey

1966 ◽  
Vol 8 (1) ◽  
pp. 22-26 ◽  
Author(s):  
E. C. Larke ◽  
R. J. Parker
Keyword(s):  
Internal Pressure ◽  
Creep Strain ◽  
Wall Thickness ◽  
Circumferential Strain ◽  
Axial Stress ◽  
Integration Procedure ◽  
Graphical Integration ◽  
Simple Equations

When considering the creep of cylinders subjected to internal pressure, the theory of Johnson et al. takes into account progressive changes of radial, circumferential and axial stress at any point in the wall thickness. This approach differs from that put forward by Bailey, who assumed that these stresses remained constant with time. The present paper summarizes an examination of both theories, with particular reference to outside and bore diameters, and presents simple equations which enable circumferential strain to be calculated without using the complex graphical integration procedure suggested by Johnson. Furthermore, it is demonstrated that these equations are mathematically identical with those derived by Bailey.

3-D Finite Element Simulation of Pulsating T-Shape Hydroforming of Tubes

2007 ◽  
Vol 340-341 ◽  
pp. 353-358 ◽  
Author(s):  
M. Loh-Mousavi ◽  
Kenichiro Mori ◽  
K. Hayashi ◽  
Seijiro Maki ◽  
M. Bakhshi
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Finite Element Simulation ◽  
Wall Thickness ◽  
Filling Ratio ◽  
Shape Accuracy ◽  
Element Simulation ◽  
Hydroforming Process ◽  
Good Agreement

The effect of oscillation of internal pressure on the formability and shape accuracy of the products in a pulsating hydroforming process of T-shaped parts was examined by finite element simulation. The local thinning was prevented by oscillating the internal pressure. The filling ratio of the die cavity and the symmetrical degree of the filling was increased by the oscillation of pressure. The calculated deforming shape and the wall thickness are in good agreement with the experimental ones. It was found that pulsating hydroforming is useful in improving the formability and shape accuracy in the T-shape hydroforming operation.

Effect of Expansion Ratio and Wall Thickness on Large-Diameter Solid Expandable Tubular after Expansion

2021 ◽  
Author(s):  
Changshuai Shi ◽  
Kailin Chen ◽  
Xiaohua Zhu ◽  
Feilong Cheng ◽  
Yuekui Qi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Performance Test ◽  
Large Diameter ◽  
Expansion Ratio ◽  
Fe Model ◽  
Laboratory Test Results ◽  
Low Efficiency ◽  
Pressure Resistance

Abstract The large-diameter solid expandable tubular with a smaller wall thickness faces the risk of internal pressure burst and external squeeze collapse in repairing damaged casing well. The internal pressure and external squeezing resistance calculation of the tubes using the analytical method require many expansion experiments and post-expansion tensile experiments, resulting in high costs and low efficiency. This paper gives a set of laboratory expansion and post-expansion performance test, which is based on the laboratory experiment and mechanical properties of material expansion. Two materials are studied: 316L and 20G. Then it analyses the error and causes of the error in the traditional analytical algorithm. Besides, it establishes an accurate finite element (FE) model to study the quantitative influence of expansion ratio and wall thickness on the burst strengths and collapse strengths of the tube. The results show that the toughness and hardening ratio of 316L is better than 20G at the same expansion ratio. The numerical simulation results of the model can effectively simulate the expansion process and the mechanical properties of SET in good agreement with the laboratory test results. The expansion ratio and wall thickness affect the mechanical properties after expansion. Thus the quantitative laws of the expansion driving force, internal pressure resistance, and external squeezing resistance under different variables are summarized. To ensure the integrity of the reinforced wellbore, the expansion ratio should not exceed 12.7%. In the current study lays a theoretical basis and technical support for optimizing SET and preventing downhole accidents.

Influence of the Wall Thickness on the Allowable and Failure Pressures of Two- and Tree-Way Globe Valve Bodies

2011 ◽  
Vol 488-489 ◽  
pp. 646-649
Author(s):  
Milan Opalić ◽  
Ivica Galić ◽  
Krešimir Vučković
Keyword(s):  
Internal Pressure ◽  
Wall Thickness ◽  
Design Method ◽  
Equivalent Plastic Strain ◽  
Strain Curve ◽  
Linear Motion ◽  
Valve Body ◽  
Failure Pressure ◽  
Critical Location ◽  
Globe Valve

A globe valve is a linear motion valve used to shut off and regulate fluid flow in pipelines. Depending on the number of process connections, they are produced as two‑ or three-way valves. The main valve component carrying the internal pressure is the valve body. For safe exploitation, the valves are designed with the allowable internal pressure taken into consideration. The aim of this paper is to investigate the influence of the wall thickness on the allowable and failure pressures of two- and tree-way globe valve bodies, DN50 and DN100 respectively. Twice-elastic-slope (TES) and the tangent‑intersection (TI) methods are used to obtain the plastic collapse pressures at the critical location which was determined (Fig. 1a and 1b) at the location where maximum equivalent plastic strain throughout the valve body thickness reaches the outer surface. Obtained values are used afterwards to calculate corresponding allowable pressures according to the limit design method, while the failure pressure at the same location was determined as the highest point from the load-maximal principal strain curve. Calculated allowable pressure values, for both valve bodies, are compared with the corresponding ones obtained using the EN standard.

AE Sources Localization Accuracy Improvement During Cross-country Gas Pipelines Testing

NDT World ◽  
2015 ◽  
Vol 18 (3) ◽  
pp. 40-42
Author(s):  
Жуков ◽  
Anton Zhukov
Keyword(s):  
Wall Thickness ◽  
Gas Pipelines ◽  
Frequency Range ◽  
Optimum Frequency ◽  
Localization Accuracy ◽  
Ae Signal ◽  
Cross Country ◽  
Pipeline Wall ◽  
Ae Signals ◽  
Operation Frequency

Introduction. The research was carried out to improve sources localization accuracy during cross-country gas pipelines testing. The research purpose is to determine an algorithm of choice for operation frequency range, AE transducers and input filters of AE equipment for different pipeline wall thicknesses Method. The AE signal was simulated on the pipelines with wall thickness from 8 to 24 mm. A few types of transducers with different amplitude-frequency characteristics were chosen for signal detection. Further we analyzed forms of the detected AE signals and stability of their velocity. Results. We have established that for each pipeline wall thickness there is a proper operation frequency range, within which the velocity of AE signals is stable and predictable. For example, for the 8 mm wall thickness the optimum frequency range is from 60 to 200 kHz. The suitable transducer for work within this range is GT200. If the work is held out of stated range, the AE signal velocity is not predictable and can vary from 500 to 5100 m/s; therefore localization of AE source turns to be impossible.

Practical Design of Aluminium Silos According to EC9-1-5

2016 ◽  
Vol 710 ◽  
pp. 97-102 ◽  
Author(s):  
Peter Knoedel ◽  
Thomas Ummenhofer
Keyword(s):  
Internal Pressure ◽  
Aluminium Alloy ◽  
Axial Compression ◽  
Wall Thickness ◽  
Imperfection Sensitivity ◽  
Building Regulations ◽  
Federal States ◽  
Buckling Resistance ◽  
Practical Design ◽  
Made In

Within the code-family of the Eurocodes, provisions for aluminium shells are given in EN 1999-1-5 (EC9) [1]. EC9-1-5 is listed in the Bavarian List of Technical Building Regulations. Thus, in Bavaria as well as in other Federal States of Germany it is mandatory to use EC9-1-5 for the verification of silos. A typical aluminium silo for industrial products might have a diameter of 3 m, a bin height of 10 m and wall thicknesses of 4 mm / 5 mm. The aluminium alloy EN AW-5754 [Al Mg3] O/H111 (EN 485-2 [2]) would be typical as well. Relevant for determining the required wall thickness is the buckling resistance under axial compression in the skirt and axial compression with coexisting internal pressure in the silo bin. When some obvious shortcomings in the formulae for coexisting internal pressure were investigated, it was found that there is a big discrepancy between scientific research, which has been done on the imperfection sensitivity of aluminium shells and the design equations in EC9-1-5. In the present paper an effort was made, in order to tackle these discrepancies and make clear, in which points the code needs amendment.

scholarly journals The research of the stress-strain state with local thinning in pipelines and determination of allowable values of concentration stress and strain

2019 ◽  
Vol 15 (5) ◽  
pp. 384-391
Author(s):  
Dmitry A. Kuzmin ◽  
Anastasia V. Andreenkova
Keyword(s):  
Stress Concentration ◽  
Internal Pressure ◽  
Wall Thickness ◽  
Strain State ◽  
Stress Strain ◽  
Flow Acceleration ◽  
Stress Strain State ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Equipment And Pipelines

Relevance. The nuclear power plant contains a large number of equipment and pipelines subject to flow acceleration corrosion. As a result of a combination of various parameters - sizes (diameters, wall thickness), operational parameters (internal pressure, temperature), steels and elements types - the number of design cases is tens of thousands, without counting the possible forms of thinning. The process of maintenance and repair at the stations are doing an assessment of the accordance of actual and allowable values of wall thicknesses. The ensuring safe operations of equipment and pipelines have been introduced correction functions for regulatory functions, taking into account the forms of thinning, to determine the permissible thinning. The aim of the work. The task is to determine the influence of the forms and types of thinning on the stress-strain state and to determine the most critical thinning for straight sections of pipelines subject to flow acceleration corrosion taking into account emergency conditions. Methods. The allowable values of stress concentration factors (deformations) of pipelines subject without flow acceleration corrosion was determined taking into account allowable values, the requirements of the federal norms and rules for emergency operating conditions. For researches of the stress concentration coefficients were used the finite element method and analytical methods for various shapes, sizes and depths of thinning. Results. A method has been developed, that allows getting the maximum allowable values of stress concentration factors (deformations) for emergency operation, which afford to determine the maximum allowable depth of thinning in emergency conditions - an above criterion. The researches have been carried out definition of the stress concentration factors for local thinning with various types of these thinning. The functions of concentration coefficients depending on the geometric parameters of local thinning wall thickness were determined for a straight section of the pipeline. As a result of the research, the dependences of the sizes of thinning on the concentration coefficients for straight pipelines were created and a master-curve was obtained. The researches were carried out take into account the load from internal pressure and bending moment.

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