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.

Plastic Limit Loads of Pad Reinforced Cylindrical Vessels Under Out-of-Plane Moment of Nozzle

2005 ◽  
Vol 128 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Z. F. Sang ◽  
H. F. Wang ◽  
L. P. Xue ◽  
G. E. O. Widera
Keyword(s):  
Finite Element ◽  
Limit Load ◽  
Plastic Limit ◽  
Element Analysis ◽  
Limit Loads ◽  
Test Models ◽  
Out Of Plane ◽  
Scale Test ◽  
Plastic Limit Load ◽  
Strain Responses

The purpose of this work is to study the plastic limit load of pad reinforced cylindrical vessels with different d/D ratios under out-of-plane moment loading on a nozzle. Three full-scale test models were designed and fabricated. A 3-D nonlinear finite element numerical analysis was also performed. Data on plastic limit moment is obtained from load-displacement and load-strain responses. The results indicate that plastic limit loads determined by test (including displacement and strain measurements) and finite element analysis are in agreement.

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.

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.

Use of Limit Load Analysis for Design of Pressure Vessel Cover

2012 ◽  
Author(s):  
Rahul Jain
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessel ◽  
Limit Load ◽  
Plastic Limit ◽  
Element Analysis ◽  
Linear Elastic ◽  
Reference Volume ◽  
Plastic Limit Load ◽  
Load Analysis

This paper explores the use of limit load analysis methods for the design of a pressure vessel manway cover as per the ASME boiler and pressure vessel code guidelines. The results of elastic and limit load finite element analysis are discussed for the design. The concept of reference volume consideration along with linear elastic finite element analysis to determine the lower bound limit load has been explored and the results are compared with the non-linear elastic-plastic limit load analysis.

Burst Pressure of Pressurized Cylinders With Hillside Nozzle

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
H. F. Wang ◽  
Z. F. Sang ◽  
L. P. Xue ◽  
G. E. O. Widera
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Experimental Models ◽  
Burst Pressure ◽  
Element Analysis ◽  
Test Models ◽  
Scale Test ◽  
Failure Location ◽  
Dimensional Instability ◽  
Good Agreement

The burst pressure of cylinders with hillside nozzle is determined using both experimental and finite element analysis (FEA) approaches. Three full-scale test models with different angles of the hillside nozzle were designed and fabricated specifically for a hydrostatic test in which the cylinders were pressurized with water. 3D static nonlinear finite element simulations of the experimental models were performed to obtain the burst pressures. The burst pressure is defined as the internal pressure for which the structure approaches dimensional instability, i.e., unbounded strain for a small increment in pressure. Good agreement between the predicted and measured burst pressures shows that elastic-plastic finite element analysis is a viable option to estimate the burst pressure of the cylinders with hillside nozzles. The preliminary results also suggest that the failure location is near the longitudinal plane of the cylinder-nozzle intersection and that the burst pressure increases slightly with an increment in the angle of the hillside nozzle.

A Study on the Effect of Non-Idealized Crack on a 90° Elbow by Using Finite Element Analysis

2018 ◽  
Author(s):  
Jae-Hee Kim ◽  
Min-Kyu Kim ◽  
Ye-Rin Choi ◽  
Doo-Ho Cho ◽  
Moon Ki Kim ◽  
...  
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Limit Load ◽  
Element Model ◽  
Assessment Method ◽  
Accurate Solution ◽  
Fe Model ◽  
Plastic Limit ◽  
Element Analysis ◽  
Plastic Limit Load

The present paper proposed the modified limit load solution related to code case N-513-4 which is currently actively researched. To apply to assessment method for an elbow in code case N-513-4, the crack should be postulated as the idealized circumferential through-wall crack (TWC). For this reason, it could be led to overestimate the results due to the assumption of real crack shape. Then, the many research which is related to an accurate solution for a straight pipe by considering realistic crack has been investigated. However, the accurate solution for the elbow with non-idealized TWC is still lacked. Therefore, based on three-dimensional finite element model, the effect of non-idealized circumferential TWC on plastic limit load was investigated under internal pressure. To do this, the finite element (FE) model and analysis procedure employed in the present numerical study were validated by comparing the present finite element analyses result with existing solutions for idealized TWC in the elbow. Then, the correction factor for calculating plastic limit load was newly proposed as a tabulated form by considering practical ranges of geometry.

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.

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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