605 Finite Element Analysis on Compact Pipe Flange Connections Subject to Internal Pressure and Bending Moment

2010 ◽  
Vol 2010 (0) ◽  
pp. 162-163
Author(s):  
Satoshi NAGATA ◽  
Toshiyuki SAWA ◽  
Takashi KOBAYASHI ◽  
Hirokazu TSUJI
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Bending Moment ◽  
Element Analysis

Finite Element Stress Analysis for Leak Tests of Pipe Flange Connections Subject to Internal Pressure and Bending Moment

2011 ◽  
Author(s):  
Satoshi Nagata ◽  
Toshiyuki Sawa ◽  
Takashi Kobayashi ◽  
Hirokazu Tsuji
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Bending Moment ◽  
Strain Gages ◽  
Element Analysis ◽  
Element Simulation ◽  
Sealing Performance ◽  
Gas Leak ◽  
Helium Gas

This paper reports the results of finite element analysis representing the sealing performance tests on the slip-on type pipe flange connections for 8 inch and 16 inch. The flange connections are subjected to internal pressure and bending moment. Internal pressure is applied by helium gas and the bending moment is loaded through 4 points bending equipment. Gas leak rates are measured by pressure decay method. During the test, the variations in the axial bolt force are monitored for all the bolts by strain gages. The pipe stress at the junction of pipe and flange is also measured. Finite element analysis simulates the tests and the simulated results are compared with the measured data. Then the behaviors of the slip-on type flange connections under internal pressure and bending moment as well as the sealing performance are clarified by the experiment and the finite element simulation.

Closed-Form Collapse Moment Equations of Elbows Under Combined Internal Pressure and In-Plane Bending Moment

2000 ◽  
Vol 122 (4) ◽  
pp. 431-436 ◽  
Author(s):  
J. Chattopadhyay ◽  
D. K. Nathani ◽  
B. K. Dutta ◽  
H. S. Kushwaha
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Closed Form ◽  
Rotation Curve ◽  
Bending Moment ◽  
Loading Conditions ◽  
Moment Equations ◽  
Element Analysis ◽  
The Moment

Elastic-plastic finite element analysis has been carried out to evaluate collapse moments of six elbows with elbow factors varying from 0.24 to 0.6. The loading conditions of combined in-plane closing/opening bending moment and varying degree of internal pressure are considered in the analysis. For each case, collapse moment is obtained by twice elastic slope method from the moment versus end-rotation curve. Based on these results, two closed-form equations are proposed to evaluate the collapse moments of elbows under combined internal pressure and in-plane closing and opening bending moment. [S0094-9930(00)00103-7]

Nonlinear Analysis of Pressurized Piping Elbows Subjected to Out-of-Plane Bending

2006 ◽  
Vol 306-308 ◽  
pp. 351-356 ◽  
Author(s):  
Asnawi Lubis ◽  
Jamiatul Akmal
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Cross Section ◽  
Bending Moment ◽  
Pressure Reduction ◽  
Element Analysis ◽  
Out Of Plane ◽  
Plane Bending ◽  
Reduction Effect

The behavior of piping elbows under bending and internal pressure is more complicated than expected. The main problem is that the coupling of bending and internal pressure is nonlinear; the resulting stress and displacement cannot be added according to the principle of superposition. In addition, internal pressure tends to act against the effect caused by the bending moment. If bending moment ovalise the elbow cross-section, with internal pressure acting against this deformation, then the ovalised cross section deform back to the original circular shape. It is then introduced the term “pressure reduction effect”, or in some literature, “pressure stiffening effect”. Current design piping code treats the pressure reduction effect equally for in-plane (closing and opening) moment and outof- plane moment. The aim of this paper is to present results of a detailed finite element analysis on the non-linear behavior of piping elbows of various geometric configurations subject to out-of-plane bending and internal pressure. Specifically the standard Rodabaugh & George nonlinear pressure reduction equations for in-plane closing moment are checked in a systematic study for out-of-plane moment against nonlinear finite element analysis. The results show that the pressure stiffening effects are markedly different for in-plane and out-of-plane bending.

Fitness for Service Assessments of Bulging and Out-of-Round Structures

2004 ◽  
Author(s):  
Peter Carter ◽  
D. L. Marriott ◽  
M. J. Swindeman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Structural Model ◽  
External Pressure ◽  
Element Analysis ◽  
Structural Imperfection ◽  
Level 2

This paper examines techniques for the evaluation of two kinds of structural imperfection, namely bulging subject to internal pressure, and out-of-round imperfections subject to external pressure, with and without creep. Comparisons between comprehensive finite element analysis and API 579 Level 2 techniques are made. It is recommended that structural, as opposed to material, failures such as these should be assessed with a structural model that explicitly represents the defect.

scholarly journals Analysis for Wrinkling Behavior of Girth-Welded Line Pipe

1996 ◽  
Author(s):  
Luiz T. Souza ◽  
David W. Murray
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Internal Pressure ◽  
Experimental Test ◽  
Element Model ◽  
Element Analysis ◽  
Line Pipe ◽  
New Era ◽  
Analytical Tools

The paper presents results for finite element analysis of full-sized girth-welded specimens of line pipe and compares these results with the behavior exhibited by test specimens subjected to constant axial force, internal pressure and monotonically increasing curvatures. Recommendations for the ‘best’ type of analytical finite element model are given. Comparisons between the behavior predicted analytically and the observed behavior of the experimental test specimens are made. The mechanism of wrinkling is explained and the evolution of the deformed configurations for different wrinkling modes is examined. It is concluded that the analytical tools now available are sufficiently reliable to predict the behavior of pipe in a manner that was not previously possible and that this should create a new era for the design and assessment of pipelines if the technology is properly exploited by industry.

Elastic and elastic-plastic finite element analysis of hollow tubes with axisymmetric internal projections under combined axial and pressure loading

2001 ◽  
Vol 36 (4) ◽  
pp. 373-390 ◽  
Author(s):  
S. J Hardy ◽  
M. K Pipelzadeh ◽  
A. R Gowhari-Anaraki
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Plastic Material ◽  
Axial Loading ◽  
Material Model ◽  
Pressure Loading ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Applied Loading

This paper discusses the behaviour of hollow tubes with axisymmetric internal projections subjected to combined axial and internal pressure loading. Predictions from an extensive elastic and elastic-plastic finite element analysis are presented for a typical geometry and a range of loading combinations, using a simplified bilinear elastic-perfectly plastic material model. The axial loading case, previously analysed, is extended to cover the additional effect of internal pressure. All the predicted stress and strain data are found to depend on the applied loading conditions. The results are normalized with respect to material properties and can therefore be applied to geometrically similar components made from other materials, which can be represented by the same material models.

scholarly journals Effect of Ovality in Inlet Pigtail Pipe Bends Under Combined Internal Pressure and In-Plane Bending for Ni-Fe-Cr B407 Material

2017 ◽  
Vol 62 (3) ◽  
pp. 1881-1887
Author(s):  
P. Ramaswami ◽  
P. Senthil Velmurugan ◽  
R. Rajasekar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Limit Load ◽  
Outer Radius ◽  
Factor H ◽  
Geometrical Shape ◽  
Element Analysis ◽  
Pipe Bend ◽  
Plane Bending

Abstract The present paper makes an attempt to depict the effect of ovality in the inlet pigtail pipe bend of a reformer under combined internal pressure and in-plane bending. Finite element analysis (FEA) and experiments have been used. An incoloy Ni-Fe-Cr B407 alloy material was considered for study and assumed to be elastic-perfectly plastic in behavior. The design of pipe bend is based on ASME B31.3 standard and during manufacturing process, it is challenging to avoid thickening on the inner radius and thinning on the outer radius of pipe bend. This geometrical shape imperfection is known as ovality and its effect needs investigation which is considered for the study. The finite element analysis (ANSYS-workbench) results showed that ovality affects the load carrying capacity of the pipe bend and it was varying with bend factor (h). By data fitting of finite element results, an empirical formula for the limit load of inlet pigtail pipe bend with ovality has been proposed, which is validated by experiments.

scholarly journals A Review on Numerical Analysis of RC Flat Slabs Exposed to Fire

2020 ◽  
Vol 27 (1) ◽  
pp. 1-5
Author(s):  
Hanadi Naji ◽  
Nibras Khalid ◽  
Mutaz Medhlom
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Numerical Analysis ◽  
Bending Moment ◽  
Mechanical And Thermal Properties ◽  
Vertical Deflection ◽  
Element Analysis ◽  
Flat Slabs ◽  
Numerical Studies ◽  
The Finite Element Analysis

This paper aims at presenting and discussing the numerical studies performed to estimate the mechanical and thermal behavior of RC flat slabs at elevated temperature and fire. The numerical analysis is carried out using finite element programs by developing models to simulate the performance of the buildings subjected to fire. The mechanical and thermal properties of the materials obtained from the experimental work are involved in the modeling that the outcomes will be more realistic. Many parameters related to fire resistance of the flat slabs have been studied and the finite element analysis results reveal that the width and thickness of the slab, the temperature gradient, the fire direction, the exposure duration and the thermal restraint are important factors that influence the vertical deflection, bending moment and force membrane of the flat slabs exposed to fire. However, the validation of the models is verified by comparing their results to the available experimental date. The finite element modeling contributes in saving cost and time consumed by experiments.

A Comparative Study on Mechanical Behavior of Pipe-Socket Threaded Joints With Taper-Taper Threads and Taper-Parallel Threads Combinations by Finite Element Analysis and Experiments

2018 ◽  
Author(s):  
Satoshi Nagata ◽  
Shinichi Fujita ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Service Condition ◽  
Internal Thread ◽  
Element Analysis ◽  
Strain Pattern ◽  
External Thread ◽  
Thread Length ◽  
The Difference

There are two types of combination between external and internal threads used in threaded pipe connections for pressure piping specified in industrial standards like JIS as well as ISO. One is the combination that taper external thread of pipe is engaged with taper internal thread of a fitting. The other is that taper external thread of pipe is engaged with parallel internal thread of a fitting. Taper thread is always used for external thread outside the pipe wall. Both taper thread and parallel one are applicable to internal thread inside the fittings. This paper evaluates the mechanical behaviors of threaded pipe-socket joints (or pipe-coupling joints) and the difference due to the thread type combinations by means of axisymmetric finite element analysis for 3/4” and 3” joints. The analysis shows that the taper-taper threads combination establishes the full-length contact over the engaged threads but the taper-parallel has only a pair of threads in contact at the 1st engaged thread from the end of socket, and the difference results in the different behaviors of the joints. Stress and strain pattern also completely differ due to the difference in the engaged thread length. No significant effect of the size has been found in the present analysis for 3/4”and 3” joints. Experimental tightening tests and pressure leak tests have also been carried out for 3/4” and 3” joints with taper-taper threads combination. The measured experimental stress for 3/4” joints has shown an agreement with the simulated one fairly well. The pressure leak tests have demonstrated that the taper-taper threaded pipe-socket joints can hold internal pressure without leakage without using thread seal tape or jointing compound under low-pressure service condition. The 3/4” joints have started leaking at 1–4MPaG of internal pressure. The 3” joints haven’t shown leakage even at 6MPaG of internal pressure applied.

Dynamic Interaction of High-Voltage Power Transformer Bushings, Turrets, and Tanks

2018 ◽  
Vol 34 (1) ◽  
pp. 397-421 ◽  
Author(s):  
Guo-Liang Ma ◽  
Qiang Xie ◽  
Andrew Whittaker
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Voltage ◽  
Power Transformer ◽  
Bending Moment ◽  
Dynamic Interaction ◽  
Electrical Performance ◽  
Element Analysis ◽  
Ground Shaking ◽  
Input Motion

High-voltage (HV) bushings are attached to a power transformer tank either directly or indirectly via turrets. Turrets are used to achieve electrical performance requirements, but their potential impact on the seismic performance of the supported bushings has not been considered. Earthquake simulator testing and finite-element analysis were used to quantify the amplification of ground shaking through tanks (220- and 500-kV) and turrets to the points of attachment of roof- and sidewall-supported bushings. Substantial amplification of motion was seen in both physical experiments and numerical simulations. Sample bracing schemes external to the transformer tank were investigated to potentially reduce the motions experienced by the bushings. Bushing tip displacements were reduced in all stiffening cases studied, but the outcomes for bending moment at the bushing-turret connection were mixed, with no change in some cases and significant reductions in others. The physical and numerical studies described in this paper make clear the importance of dynamic interaction of bushings, turrets, and the power transformer tank. The methods currently used to address the amplification of input motion from the base of a tank to the points of attachment of its bushing are inadequate. The seismic design of HV power transformer tanks and turrets should be supported by finite-element analysis of validated models to avoid dynamic interaction in the bushing-turret-tank system, to minimize seismic demand on the transformer bushings, and to minimize the risk of substation damage in earthquakes.

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