On Stresses in Pipeline Expansion Bellows

1988 ◽  
Vol 110 (2) ◽  
pp. 215-217 ◽  
Author(s):  
A. V. Singh
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Analytical Procedure ◽  
Circumferential Stress ◽  
Shell Element ◽  
Shells Of Revolution ◽  
Axisymmetric Shell ◽  
Stress Components ◽  
Stress Patterns ◽  
Theory Of Shells

An analytical procedure employing the general theory of shells of revolution and finite element method is presented to examine the stress patterns along the convolution of the pipeline expansion bellows under axial compression. A simple three-node axisymmetric shell element is used to compute axial and circumferential stress components. Three example problems which include two corrugated-pipe-type and one U-type bellows, have been analyzed. Comparison of the present numerical results with the experimentally procured data from the open literature illustrates the reliability, accuracy, elaborateness and versatility of this approach.

scholarly journals Local Elastic and Geometric Stiffness Matrices for the Shell Element Applied in cFEM

2017 ◽  
Author(s):  
Dávid Visy ◽  
Sándor Ádány
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Element ◽  
Numerical Examples ◽  
Geometric Stiffness ◽  
Stiffness Matrices ◽  
Plane Element ◽  
Unusual Combination ◽  
Shell Finite Element ◽  
Lagrange Strain

In this paper local elastic and geometric stiffness matrices of ashell finite element are presented and discussed. The shell finiteelement is a rectangular plane element, specifically designedfor the so-called constrained finite element method. One of themost notable features of the proposed shell finite element isthat two perpendicular (in-plane) directions are distinguished,which is resulted in an unusual combination of otherwise classicshape functions. An important speciality of the derived stiffnessmatrices is that various options are considered, whichallows the user to decide how to consider the through-thicknessstress-strain distributions, as well as which second-order strainterms to consider from the Green-Lagrange strain matrix. Thederivations of the stiffness matrices are briefly summarizedthen numerical examples are provided. The numerical examplesillustrate the effect of the various options, as well as theyare used to prove the correctness of the proposed shell elementand of the completed derivations.

SCC in Shroud Support Cylinder Vertical Weld Lines (Tokai-2)

2006 ◽  
Author(s):  
Yuichi Arita ◽  
Koji Dozaki ◽  
Fumio Manabe ◽  
Satoshi Kanno
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Circumferential Stress ◽  
Weld Line ◽  
Critical Length ◽  
Seismic Load ◽  
Finite Element Method Analysis ◽  
Integrity Assessment ◽  
Method Analysis ◽  
Element Method

SCC was found outer surface of shroud support cylinder vertical weld lines (V8) made of Nickel based alloy, alloy 182, for Tokai-2 (BWR-5) operated since 1978. Three SCC among 4 weld lines of V8 were observed. The material of Alloy182 was known to have SCC potential in BWR environment. Based on the result of finite element method analysis, it was estimated that tensile circumferential stress generated at the upper corner of cylinder corresponding crack location when H7 welded. The integrity assessment against seismic load in design was performed using shell model in finite element method analysis. It assumed conservatively that four vertical through wall cracks along whole length of V8 weld lines and four horizontal through wall partial cracks along H7 weld line at intersections of V8 and H7. The collapse load was estimated by twice slope method, a kind of limit load analysis. As the result of the integrity assessment, a critical horizontal through wall crack length along H7 weld line was about 1400 mm per one crack (about 70% of all circumferences). SCC growth was evaluated to reach the critical length after about 20 years, where maximum crack growth rate, 63mm/year was assumed. It is not judged that the immediate repair of vertical SCC is necessary.

Simulation and Analysis on the Blind Hole Method Using the Finite Element Method

2013 ◽  
Vol 328 ◽  
pp. 990-994
Author(s):  
Chun Ho Yin ◽  
Chao Ming Hsu ◽  
Ping Shen Su ◽  
Jao Hwa Kuang
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Strain Gage ◽  
Hole Drilling ◽  
Drilling Process ◽  
Dimensionless Parameters ◽  
Inconel 690 ◽  
Stress Components ◽  
Element Method

This study investigates the effectiveness of the hole-drilling strain gage method on residual stress estimation. The thermal elastic-plastic model of the commercial Marc finite element method package is used to simulate and build up the hole-drilling process and residual stress distribution. Two Inconel 690 alloy plate welded with GTAW filler I-52 solder are first simulated using the Marc software. The traditional hole-drilling process is then simulated. The simulated residual strain variation data is incorporated into the hole-drilling strain-gage method to derive the possible residual stress components. The effects of drilling depth and drill size on the accuracy of residual stress estimates are also discussed. A comparison of stress components estimated from the traditional hole-drilling strain gage method and simulated from the Marc software is presented. The modified dimensionless parameters are provided by applying the optimum technique. The numerical results indicate that the proposed dimensionless parameters can significantly improve the accuracy of estimated residual stress components.

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