Flexural Rigidity of Annular Flange Connections

1998 ◽  
Vol 120 (2) ◽  
pp. 164-169 ◽  
Author(s):  
H. Kimura ◽  
S. Nonaka
Keyword(s):  
Cylindrical Shell ◽  
Axial Force ◽  
Calculation Method ◽  
Flexural Rigidity ◽  
Bending Moments ◽  
Bolted Connections ◽  
Sealing Performance ◽  
Good Agreement

In order to analyze the vibration of a structure whose elements are connected with bolts, it is necessary to estimate the flexural rigidity of bolted connections. Some studies have been reported on annular flange connections subjected to external bending moments. In these studies, the bolt axial force and the sealing performance are examined in detail, but their flexural rigidity is not sufficiently discussed. This paper deals with a calculation method to estimate the flexural rigidity of bolted annular flange connections subjected to external bending moments. In the analysis, a model for estimating the flexural rigidity is proposed, taking account of the dispersiveness of bolt disposition and the rigidity of flange-shell junction. That is, the annular flange is replaced with a plate and the hub with a cylindrical shell. For verification, experiments are performed. Calculated results are in fairly good agreement with experimental ones.

FEM Stress Analysis and Sealing Performance in Pipe Flange Connections With Adhesive Subjected to Internal Pressure and External Bending Moments

2005 ◽  
Author(s):  
Masahide Katsuo ◽  
Toshiyuki Sawa ◽  
Yuki Kikuchi
Keyword(s):  
Internal Pressure ◽  
Stress Analysis ◽  
Bending Moment ◽  
Fem Analysis ◽  
Bending Moments ◽  
3 Dimensional ◽  
Leakage Test ◽  
Sealing Performance ◽  
Flange Thickness ◽  
Good Agreement

This study deals with the stress analysis and the estimation of sealing performance of the pipe flange connections with an adhesive under an internal pressure and an external bending moment are analyzed by using the 3-dimensional elastic finite element method (FEM). The experiment of the leakage test of the connections with an adhesive was carried out by applying the above loads to the connections. From the FEM analysis, the following results were obtained; (1) when an internal pressure is applied to the flange connections, the compressive stress at the interface between a flange and an adhesive increases proportionally from the inner side of the interface to outside, and (2) when an internal pressure and a bending moment apply to the flange connections, the stress distribution at the half part of the interface increases as the external bending moments increase and also Young’s modulus of the adhesive increases. From the experiments, the following results were obtained: (1) sealing performance of the pipe flange connections with an adhesive under an internal pressure and an external bending moment increases as the flange thickness and an initial clamping force of bolts increases and (2) the sealing performances were not found between the connections with an adhesive and that with a gasket combining an adhesive. Furthermore, the numerical results are in fairly good agreement with the experimental results.

FEM Stress Analysis and Mechanical Characteristics of Bolted Pipe Flange Connections With PTFE Blended Gaskets Subjected to External Bending Moments and Internal Pressure

2017 ◽  
Author(s):  
Koji Sato ◽  
Toshiyuki Sawa ◽  
Riichi Morimoto ◽  
Takashi Kobayashi
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Mechanical Characteristics ◽  
Bending Moment ◽  
Leak Rate ◽  
Bending Moments ◽  
Four Point Bending ◽  
Sealing Performance ◽  
The Difference ◽  
Good Agreement

In designing of pipe flange connections with gaskets, it is important to examine the mechanical characteristics of the connections subjected to external bending moments due to earthquake such as the changes in hub stress, axial bolt forces and the contact gasket stress distribution which governs the sealing performance. One of the authors developed the PTFE blended gaskets and the authors examined the mechanical characteristics of the connections with the PTFE blended gaskets under internal pressure. However, no research was done to examine the mechanical characteristics of the connections with the newly developed PTFE blended gasket subjected to external bending moment due to earthquake. The objectives of the present study are to examine the mechanical characteristics of the connection with PTFE blended gasket subjected to external bending moment and internal pressure and to discuss the difference in the load order to the connections between the internal pressure and the external bending moments. The changes in the hub stress, the axial bolt force and the contact gasket stress distribution of the connection are analyzed using FEM. Using the obtained the gasket stress distribution and the fundamental data between the gasket stress and the leak rate for a smaller test gasket, the leak rate of the connection with the gasket is predicted under external bending moment and internal pressure. In the FEM calculations, the effects of the nominal diameter of pipe flanges on the mechanical characteristics are shown. In the experiments, ASME class 300 4 inch flange connection with 2m pipes at both sides is used and the test gasket is chosen as No.GF300 made by Nippon Valqua Industries, ltd. Four point bending moment is applied to the connection. The FEM results of the hub stress and the axial bolt forces are in a fairly good agreement with the experimental results. In addition, the FEM results of the leak rate are fairly coincided with the measured results.

An Analysis of Circular Bolted Flanged Joints on Solid Round Bars Subjected to External Bending Moments

2000 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Tsuneshi Morohoshi ◽  
Akihiro Shimizu
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Three Dimensional ◽  
Bending Moment ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Bending Moments ◽  
Sealing Performance ◽  
Contact Stress Distribution ◽  
Good Agreement

Abstract In designing bolted joints, it is important to know the contact stress distribution which governs the clamping effect or the sealing performance and to estimate the load factor (the ratio of an increment in axial bolt force to an external load) from bolt design standpoint. The clamping force by bolts and the external bending moment are axi-asymmetrical loads and not many investigations have seen reported which treat axi-asymmetrical. In this paper, the clamping effect, and the load factor for the case of solid round bars with circular flanges, subjected to external bending moments, are analyzed as an axi-asymmetrical problem using the three-dimensional theory of elasticity. Experiments were carried out concerning the contact stress distribution, and the load factor for the external bending moment (a relationship between an increment in axial bolt force, and external bending moment). The analytical results were in fairly good agreement with the experimental ones.

Buckling of Cylindrical Shells Subjected to Nonuniform Axial Loads

1977 ◽  
Vol 44 (4) ◽  
pp. 714-720 ◽  
Author(s):  
A. Libai ◽  
D. Durban
Keyword(s):  
Cylindrical Shell ◽  
Closed Form ◽  
Axial Force ◽  
Entire Range ◽  
Axial Loads ◽  
Buckling Modes ◽  
Harmonic Index ◽  
Linear Buckling ◽  
Interaction Law ◽  
Good Agreement

The linear buckling problem of a cylindrical shell subjected to circumferentially varying axial edge loads or thermal loads is considered. The case of an oscillatory loading having a cosinusidal form with a single arbitrary harmonic index is treated first. Closed-form expressions for the critical eigenvalues are obtained, spanning the entire range of the harmonic index. Buckling modes are also presented. An interaction law among harmonic loadings based on existing numerical evidence is then postulated. This leads to the capability of calculating the buckling load for any given distribution. The method is compared, and good agreement is obtained, with published results on the heating of an axial strip. It is then used to calculate the buckling of a cylindrical shell subjected to a concentrated axial force.

A Calculation Method of the Load Factor and Design for Bolted Gasketed Pipe Flange Connections Under Internal Pressure

2019 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Toshio Mabuchi ◽  
Koji Sato
Keyword(s):  
Internal Pressure ◽  
Calculation Method ◽  
Leak Rate ◽  
Load Factor ◽  
Bolted Connections ◽  
Gas Leakage ◽  
Nominal Diameter ◽  
Bolt Preload ◽  
Spring Constants ◽  
Good Agreement

Abstract The contact gasket stress reduces when the bolted gasketed pipe flange connections are subjected to internal pressure. In designing the bolted connections, it is needed to predict the reduced contact gasket stress, so, it is necessary to know the load factor. However, it is difficult to estimate the value of the load factor of the connections under internal pressure. In the previous paper (2018PVP), a more simpler calculation method was proposed. However, a more accuracy for obtaining the values of the load factor is desirable using the spring constants Ktg and Kcg. In the present paper, some calculation models for the spring constants are improved. Then, the values of the load factor for JIS 10K flange connections and ASME B16 flange connections with spiral wound gaskets are shown. The values of the load factor for the above connections are in a fairy good agreement with the FEM results. Using the obtained load factor, the residual contact gasket stress and an amount of gas leakage are predicted. The obtained calculated results of the load factor and the amount of the leakage are in a fairly good agreement with FEM results, and the measured results for 24” connection. As a result, the value of the load factor for the connections with larger nominal diameter is found to be negative and it decreases as the nominal flange diameter increases. In addition, a method how to determine the bolt preload for satisfying a give allowable leak rate is demonstrated.

Analysis of Straight and Curved Beam-Columns

1951 ◽  
Vol 18 (3) ◽  
pp. 283-284
Author(s):  
C. M. Tyler ◽  
J. G. Christiano
Keyword(s):  
Axial Force ◽  
Relaxation Method ◽  
Curved Beam ◽  
Bending Moments ◽  
Structural Members ◽  
Beam Columns ◽  
Numerical Example ◽  
Number Of Segments

Abstract A method of analysis is developed for calculating the effects of deflection and axial force on the bending moments of structural members having both beam and column loadings. The member is divided into a number of segments and analyzed by a relaxation method directly in terms of the bending moments at each segment. This analysis is applicable to beam-columns of any shape and stiffness, and for any type of loading. A numerical example of an irregularly curved beam-column is included.

Modeling of contact-induced radial cracking in ceramic bilayer coatings on compliant substrates

2003 ◽  
Vol 18 (5) ◽  
pp. 1275-1283 ◽  
Author(s):  
Chun-Hway Hsueh ◽  
Pedro Miranda
Keyword(s):  
Flexural Rigidity ◽  
Ceramic Coatings ◽  
Analytical Expression ◽  
Bilayer Coating ◽  
Compliant Substrates ◽  
Dental Crowns ◽  
Plates On Elastic Foundation ◽  
Radial Cracks ◽  
Good Agreement ◽  
Bilayer Coatings

Contact-induced radial cracking in ceramic coatings on compliant substrates was analyzed recently. Radial cracks initiate at the coating/substrate interface beneath the contact where maximum flexural tension occurs, and an analytical expression for the onset of radial cracking in monolayer coatings was formulated on the basis of the classical solution for flexing plates on elastic foundation. In the present study, the analytical expression was derived for the case of ceramic bilayer coatings on compliant substrates, which have significant applications in the structure of dental crowns. It was found that the analytical solution for bilayer-coating/substrate systems can be obtained from that of monolayer-coating/substrate systems by replacing the neutral surface position and the flexural rigidity of monolayer coating with those of bilayer coating. The predicted critical loads for initiating radial cracking were found to be in good agreement with existing measurements and finite element results for glass/alumina, glass/glass-ceramic, and glass/Y2O3-stabilized ZrO2polycrystal bilayers on polycarbonate substrates. Limitations of the present analysis are discussed.

Study on Static Design Methods of Plain Steel Plate-Light Weight Concrete Hollow Composite Decks

2012 ◽  
Vol 166-169 ◽  
pp. 610-615
Author(s):  
Yong Yang ◽  
Kang An ◽  
Su Sheng Zeng ◽  
Jian Yang Xue
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Steel Plate ◽  
Flexural Rigidity ◽  
Design Methods ◽  
Light Weight ◽  
Calculation Methods ◽  
Direction Parallel ◽  
Light Weight Concrete ◽  
Calculation Results

Based on the experiment results of five plain steel plate-light weight concrete hollow deck specimens, the design methods of the composite decks which mainly including the calculation method of the bearing capacity and calculation method of the flexural rigidity were introduced. In the paper, the bearing capacity and flexural rigidity of the composite at two orthogonal directions, which including the direction parallel to the pipes and the direction perpendicular to the pipes, were both introduced. The calculation results of the bearing capacity and middle-span deflection were in good agreement with those of the experimental results, and in the return calculation methods were verified. Therefore, the design methods and calculation methods were useful to the design of this new type composite deck.

Limit Analysis for Combined Edge and Pressure Loading on a Cylindrical Shell

1971 ◽  
Vol 93 (4) ◽  
pp. 998-1006
Author(s):  
H. S. Ho ◽  
D. P. Updike
Keyword(s):  
Cylindrical Shell ◽  
Velocity Field ◽  
Axial Force ◽  
Shear Force ◽  
Circular Cylindrical Shell ◽  
Yield Condition ◽  
External Pressure ◽  
Tresca Yield Condition ◽  
Stress States ◽  
Range Of Values

Equations describing the stress field and velocity field occurring in a circular cylindrical shell at plastic collapse are derived corresponding to stress states lying on each face of a yield surface for a uniform shell of material obeying the Tresca yield condition. They are then applied to the case of a shell under combined axisymmetric loadings (moment, shear force, and axial force) at one end and uniform internal or external pressure on the lateral surface. For a sufficiently long shell, complete solutions are obtained for a fixed far end, and for a certain range of values of axial force and pressure, they are obtained for a free far end. All the solutions are represented by either closed form or by quadratures. It is shown that in many cases the radial velocity field is proportional to the shear force.

Pressurized Cylindrical Shell With a Rigid Circular Inclusion

1978 ◽  
Vol 100 (2) ◽  
pp. 158-163 ◽  
Author(s):  
D. H. Bonde ◽  
K. P. Rao
Keyword(s):  
Differential Equation ◽  
Cylindrical Shell ◽  
Shallow Shell ◽  
Circular Inclusion ◽  
Hankel Functions ◽  
Curvature Parameter ◽  
Shell Equations ◽  
Limiting Case ◽  
Rigid Circular Inclusion ◽  
Good Agreement

The effect of a rigid circular inclusion on stresses in a cylindrical shell subjected to internal pressure has been studied. The two linear shallow shell equations governing the behavior of a cylindrical shell are converted into a single differential equation involving a curvature parameter and a potential function in nondimensionalized form. The solution in terms of Hankel functions is used to find membrane and bending stressses. Boundary conditions at the inclusion shell junction are expressed in a simple form involving the in-plane strains and change of curvature. Good agreement has been obtained for the limiting case of a flat plate. The shell results are plotted in nondimensional form for ready use.

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