Strength Behavior of Hot-Tapped Pipeline Under Internal Pressure Load

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
B. H. Wu ◽  
Z. F. Sang ◽  
Z. L. Wang ◽  
G. E. O. Widera
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Three Dimensional ◽  
Plastic Limit ◽  
Element Analysis ◽  
Pressure Load ◽  
Limit Pressure ◽  
Strength Behavior ◽  
Plastic Limit Pressure

The objective of this study is to investigate the strength behavior and plastic limit pressure of hot-tapped pipelines under an internal pressure load. Two full scale test models were fabricated for the experiment. A three-dimensional nonlinear finite element analysis was also carried out. The plastic limit pressure was determined approximately by use of the twice the elastic-slope criterion. The results indicate that plastic limit pressures obtained by experiment and finite element analysis are in good agreement. On the basis of the above results, a parametric analysis of the plastic limit pressure was carried out and resulted in the development of formulas useful for the design of hot-tapped pipelines.

Plastic Limit Pressure of Pressurized Cylinders With Hillside Nozzle

2006 ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
L. P. Xue ◽  
G. E. O. Widera
Keyword(s):  
Finite Element ◽  
Limit Load ◽  
Experimental Models ◽  
Plastic Limit ◽  
Element Analysis ◽  
Design Guideline ◽  
Limit Pressure ◽  
Test Models ◽  
Scale Test ◽  
Plastic Limit Pressure

Cylinder-nozzle intersections are widely used in pressure vessel and piping industries. In order to get better mixing and energy exchange of the reactants, pipe-nozzle intersection with hillside nozzle is applied more and more widely. The purpose of this work is to investigate the plastic limit load of cylinders with hillside nozzle subjected to internal pressure. Three full-scale test models with different angles of the hillside nozzle were designed and fabricated specially for the test using strain gagues. 3-D finite element numerical simulations on the experimental models were performed. Based on both results, a group of basic data on plastic limit pressure defined by double elastic-slope method for cylinders with hillside nozzle is approximately obtained according to load-strain responses, and the plastic limit pressures determined by test and finite element analysis are in good agreement. The results indicate that the limit pressure increases with the increment of the angle of the hillside nozzle, and compared with radial nozzles in cylinders, the hillside nozzles have higher limit pressure, which can be served as the basis for developing a design guideline for pressurized cylinders with various angles of hillside nozzle.

scholarly journals Plastic limit load of ellipsoidal pressure vessel head with nozzle under internal pressure loading

2013 ◽  
Vol 18 (4) ◽  
pp. 1263-1274 ◽  
Author(s):  
V.N. Skopinsky ◽  
N.A. Berkov ◽  
A.B. Smetankin
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Limit Load ◽  
Rate Of Change ◽  
Pressure Loading ◽  
Plastic Limit ◽  
Elastic Plastic ◽  
Limit Pressure ◽  
Plastic Limit Load ◽  
Plastic Limit Pressure

Abstract A new method and numerical procedure for determining the plastic limit load in an ellipsoid-cylinder intersection using the elastic-plastic finite element analysis are presented. The proposed method is based on the maximum criterion of the rate of change of the relative plastic work. For the elastic-plastic analysis of the nozzle connections the 2D finite element method and plasticity theory with strain hardening are used. The results of the comparison of the plastic limit pressure obtained on the basis of different known criteria and the proposed criterion are presented. A parametric study of ellipsoidal heads with a nozzle under internal pressure loading was performed. The effects of nondimensional geometric parameters of shell intersection on the plastic limit pressure are discussed.

Analysis and Experiments on the Plastic Limit Load of Elbows under Combined Pressure and In-Plane Closing Bending Moment

2013 ◽  
Vol 774-776 ◽  
pp. 1090-1097 ◽  
Author(s):  
Zhi Xiang Duan ◽  
Kun Shi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Safety Assessment ◽  
Bending Moment ◽  
Limit Load ◽  
Experimental Results ◽  
Plastic Limit ◽  
Element Analysis ◽  
Limit Pressure ◽  
Plastic Limit Load

This paper discusses the plastic limit load of elbows without defects and with local thinned area (LTA) in the extrados under combined pressure and in-plane closing bending moment. Finite element analysis (FEA) and experiments have been used. The results of FEA show that, for the elbows without defects, when the ratio of pressure to the limit pressure (P/PL) is smaller than 0.469, the limit moment of elbows increases with the increasing pressure; when the ratio (P/PL) is bigger than 0.469, the limit moment of elbow decreases with the increasing pressure. For the elbows with LTA, the FEA results show that with different LTA the variation of the limit load of elbows to the pressure is different. Perhaps, the limit moment of elbows always decreases with the increasing pressure. It is also likely that the limit moment of elbows increases with the increasing pressure and then decreases with the increasing pressure. The results of FEA are consistent with the experimental results. By fitting the results of FEA, the safety assessment figure for elbows under combined pressure and in-plane closing bending moment is drawn.

Plastic Analysis for Cylindrical Vessels Under In-Plane Moment on the Nozzle

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
B. H. Wu ◽  
Z. F. Sang ◽  
G. E. O. Widera
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Limit Load ◽  
Cylindrical Vessel ◽  
Plastic Limit ◽  
Element Analysis ◽  
Test Models ◽  
Scale Test ◽  
Plastic Limit Load

The objective of this paper is to determine the plastic limit moment for cylindrical vessels with a nozzle under in-plane moment loading. Three full scale test models with different d/D ratios were fabricated for the experiment. A three-dimensional nonlinear finite element analysis was also performed. The plastic limit moment of the cylindrical vessel-nozzle connections was determined approximately by the twice-elastic-slope criterion. The results indicate that the plastic limit moments obtained by the experiment and finite element analysis are in good agreement. On the basis of the above results, a parametric analysis of the plastic limit moment for cylindrical vessels under in-plane moment on the nozzle was carried out, and an empirical formula is proposed. The results can serve as a supplement to the available data of plastic limit load for cylindrical vessel-nozzle connection structures under external load.

Three-Dimensional Versus Axisymmetric Finite-Element Analysis of a Cylindrical Vessel Inlet Nozzle Subject to Internal Pressure—A Comparative Study

1978 ◽  
Vol 100 (2) ◽  
pp. 134-140 ◽  
Author(s):  
J. B. Truitt ◽  
P. P. Raju
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Comparative Study ◽  
Internal Pressure ◽  
Three Dimensional ◽  
Element Analysis ◽  
Stress Indices ◽  
Modeling Techniques ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

This paper presents a comparative study between a three-dimensional and an axisymmetric finite-element analysis of a reactor pressure-vessel inlet nozzle subject to internal pressure. A quarter-symmetric section of the nozzle is modeled with a three-dimensional quadratic isoparametric finite element. This comparative study proves that the axisymmetric analysis is unconservative if based upon common axisymmetric modeling techniques. This inadequacy, for the PWR vessel inlet nozzle studied herein, can be offset by a modification of the modeling techniques, i.e., if the value of the radius of the equivalent spherical vessel is taken as 3.2 instead of, say, 2. The results of the three-dimensional finite-element analysis are also compared with those of a photo-elastic stress analysis and with the stress indices indicated by the ASME Section III Code. These additional comparisons, based upon a continuous distribution of hoop and tangential stress indices in both the transverse and longitudinal planes, shows good agreement between the three-dimensional finite-element and photoelastic analyses. The ASME Section III stress indices are found to be relatively conservative.

Behavior of gasketed bolted pipe flange joint under combined internal pressure, axial, and bending load: Three-dimensional numerical study

2017 ◽  
Vol 232 (3) ◽  
pp. 314-322 ◽  
Author(s):  
Muhammad Abid ◽  
Niaz B Khan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Structural Integrity ◽  
Numerical Study ◽  
Three Dimensional ◽  
External Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Bending Load

Optimized performance of joint is categorized by its “structural integrity” and “sealing capability”. In literature, limited data are available regarding the performance of gasketed bolted flanged joint under combined internal and external loading; hence an optimized joint performance cannot be addressed. In this paper, a detailed three-dimensional nonlinear finite element analysis of bolted gasketed flange joint is performed, to study its performance under combined internal (pressure) and external (axial and bending) load. Results of the finite element analysis are compared with the experimental results available in literature providing the validation of the numerical approach developed.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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