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.

Stress Analysis of Bolted Joints of Flat Cover With Tap Bolts in a Pressure Vessel

1999 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Akihiro Karasawa ◽  
Akihiro Shimizu
Keyword(s):  
Contact Stress ◽  
Pressure Vessel ◽  
Three Dimensional ◽  
Bending Moment ◽  
Theory Of Elasticity ◽  
Contact Stresses ◽  
Ultrasonic Waves ◽  
Bolted Joints ◽  
Load Factor ◽  
Sealing Performance

Abstract Bolted joints with gaskets have been designed empirically, and the sealing performance is not made clear by theoretical analyses because the contact stress distribution between the gasket and the flanges are not clarified when an internal pressure is applied to the joint. The present paper, discusses the distribution of contact stresses in the bolted joints fastened with tap bolts, when a clamped part with a gasket is the cover of a pressure vessel and is a circular flange. The distribution of contact stresses is analyzed as a three-body contact problem, using the three-dimensional theory of elasticity. Moreover, the contact stress is measured by means of ultrasonic waves. In addition, the load factor (the ratio of an increment of the axial bolt force to an external load) and the maximum stress caused in bolts are analyzed taking into account the bending moment. For verification, experiments are carried out, and the analytical results are found in fairly good agreement with the experimental ones. It was found that the sealing performance was improved when Young’s modulus of the gaskets was decreased and the gasket thickness was increased.

On the Characteristics of Rectangular Bolted Flanged Connections With Gaskets Subjected to External Tensile Loads and Bending Moments

1994 ◽  
Vol 116 (2) ◽  
pp. 207-215 ◽  
Author(s):  
T. Morohoshi ◽  
T. Sawa
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Maximum Stress ◽  
Tensile Load ◽  
Bending Moment ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Body Contact ◽  
Three Body ◽  
Contact Stress Distribution

This paper deals with the characteristics of a rectangular bolted connection of “T” shape with a gasket (filler plate), in which the flanges and a gasket (filler plate) are fastened with two bolts and nuts, and are then subjected to an external tensile load or a bending moment. The contact stress distribution which governs the sealing performance (clamping effect), the load factor (the relationship between an increment of axial bolt force and an external load), and the maximum stress produced in the bolt were analyzed by using a two-dimensional theory of elasticity as a three-body contact problem. Experiments were performed concerning the load factor and the maximum stress produced in the bolt. The analytical results are fairly consistent with experimental ones. The effects on the load factor and the contact stress distribution were examined for variation in Young’s modulus of different gaskets and the different distances between the bolt holes.

A Stress Analysis of a Taper Hub Flange With a Bolted Flat Cover

1997 ◽  
Vol 119 (3) ◽  
pp. 293-300
Author(s):  
T. Sawa ◽  
N. Higurashi ◽  
T. Hirose
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Bolted Connection ◽  
Body Contact ◽  
The Moment ◽  
Flat Cover ◽  
The Relationship ◽  
Contact Stress Distribution

A bolted connection consisting of a cover on a pressure vessel flange with a metallic flat gasket on raised faces is analyzed as a four-body contact problem using axisymmetrical theory of elasticity. The contact stress distribution, the load factor (the relationship between an increment of bolt axial force and an internal pressure), and the gasket properties (the gasket seating width and the moment arm) are examined. In the analysis, the cover is replaced with a finite solid cylinder. The metallic flat gasket, the flange, and the hub are replaced with finite solid cylinders. The effects of the stiffness and the thickness of various size gaskets on the contact stress distribution are obtained by numerical calculations. Experiments were carried out to obtain the load factor, the maximum stress produced in bolts, and the stress produced on the hub. The analytical results obtained are shown to be consistent 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.

The Interface Boundary Conditions for Bolted Flanged Connections

1976 ◽  
Vol 98 (4) ◽  
pp. 277-282 ◽  
Author(s):  
J. C. Thompson ◽  
Y. Sze ◽  
D. G. Strevel ◽  
J. C. Jofriet
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Plate Theory ◽  
Contact Region ◽  
Three Dimensional ◽  
Surface Region ◽  
Prestressing Force ◽  
Flange Thickness ◽  
Interface Boundary Conditions ◽  
Contact Stress Distribution

In most bolted connections, the unknown interface pressure distribution and the extent of the contact region are essential parameters in any stress analysis. Concerning these parameters, experimental and numerical studies of a model of an isolated single-bolt region show the following. The contact region between the flanges depends almost exclusively on the ratio of the flange thickness to the diameter of the surface region of each flange over which the bolt prestressing force is distributed; the contact zone is virtually independent of both the level of prestressing force and of the size of the bolt hole; and the contact stress distribution for a typical range of parameters is very closely approximated by a truncated conical distribution. The studies also delineate the regions of the flanges around each bolt where the stress state is strongly three-dimensional and regions where simple plate theory is applicable. The relationships established between the contact stress distribution and the various geometric parameters are presented in a form immediately applicable by designers.

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.

Analysis of Cord-Reinforced Poly-Rib Serpentine Belt Drive With Thermal Effect

2005 ◽  
Vol 127 (6) ◽  
pp. 1198-1206 ◽  
Author(s):  
G. Song ◽  
K. Chandrashekhara ◽  
W. F. Breig ◽  
D. L. Klein ◽  
L. R. Oliver
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Three Dimensional ◽  
Single Layer ◽  
Material Model ◽  
Element Model ◽  
Shear Angle ◽  
Velocity Variation ◽  
Serpentine Belt ◽  
Contact Stress Distribution

This paper investigates the operation of an automotive poly-rib serpentine belt system. A three-dimensional dynamic finite element model, consisting of a driver pulley, a driven pulley, and a complete five-rib V-ribbed belt, was created. Belt construction accounts for three different elastomeric compounds and a single layer of reinforcing cords. Rubber was considered incompressible hyperelastic material, and cord was considered linear elastic material. The material model accounting for thermal strains and temperature-dependent properties of the rubber solids was implemented in ABAQUS∕EXPLICIT code for the simulation. A tangential shear angle and an axial shear angle were defined to quantify shear deformations. The shear angles were found to be closely related to velocity variation along contact arc and the imbalanced contact stress distribution on different sides of the same rib and on different ribs. The temperature effect on shear deformation, tension and velocity variation, and contact stress distribution was investigated and shown in comparison to the results for the same system operating at room temperature.

A Stress Analysis of Pipe Flange Connections

1991 ◽  
Vol 113 (4) ◽  
pp. 497-503 ◽  
Author(s):  
T. Sawa ◽  
N. Higurashi ◽  
H. Akagawa
Keyword(s):  
Maximum Stress ◽  
Three Dimensional ◽  
Theory Of Elasticity ◽  
Contact Stresses ◽  
Load Factor ◽  
Dimensional Theory ◽  
Body Contact ◽  
Sealing Performance ◽  
Three Body ◽  
The Relationship

The use of pipe flange connections is standardized in the codes of JIS, ASME, DIN and so on. However, these codes are almost entirely dependent on experience, and subsequently some problems concerning pipe flange connections have been encountered. In the present paper, the distribution of contact stresses which governs the sealing performance is analyzed as a three-body contact problem, using an axisymmetrical three-dimensional theory of elasticity. The effects of the stiffness and the thickness of raised face metallic gaskets on the contact stresses and the effective gasket seating width are shown by numerical calculation. Moreover, stresses produced on the hub, the load factor (the relationship between an increment of bolt axial force and an internal pressure), and the maximum stress caused in bolts are analyzed. For verification, experiments are carried out. The analytical results are satisfactorily consistent with the experimental results.

FEM Stress Analysis and Mechanical Characteristics of Bolted Pipe Connections With Larger Nominal Diameter Inserting PTFE Blended Gasket Under Internal Pressure

2018 ◽  
Author(s):  
Koji Sato ◽  
Toshiyuki Sawa ◽  
Xing Zheng
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Performance Prediction ◽  
Mechanical Characteristics ◽  
Leak Rate ◽  
Load Factor ◽  
Flange Connection ◽  
Nominal Diameter ◽  
Sealing Performance ◽  
Good Agreement

The sealing performance prediction of bolted pipe flange connections with gaskets is important factor. However, it is known that the sealing performance of the larger nominal diameter connection is worse than that with smaller nominal diameter connection due to the flange rotation. Furthermore, recently PTFE blended gaskets were developed newly and the excellent sealing performance in the bolted pipe flange connection with smaller nominal diameter is found. So, it is necessary to examine the sealing performance and the mechanical characteristics of pipe flange connections with larger nominal diameter under internal pressure. The objectives of present study are to examine the mechanical characteristics of the pipe flange connection with PTFE blended gasket under internal pressure such as the load factor, the contact gasket stress distribution and the sealing performance using FEM and experiments. Using the obtained contact gasket stress distribution and the fundamental leak rate for smaller PTFE gasket, the leak rate of the connection is predicted under internal pressure. In the FEM calculation, the effects of the nominal diameter of pip flange connections on the mechanical characteristics are shown. In the experiments, ASME class 300 24” pipe flange connections is used and the gasket is chosen as No.GF300 in PTFE blended gaskets. The FEM results of the axial bolt forces are in a fairly good agreement with the experimental results. In addition, the leak rate obtained from the FEM calculations are fairly coincided with the measured results. The mechanical characteristics of pipe flange connection with PTFE blended gasket are compared with those with spiral wound gasket.

An Analytical Model for Predicting Contact Stress and Sliding Wear of a Three-Dimensional Textured Surface

2009 ◽  
Author(s):  
Elon J. Terrell ◽  
C. Fred Higgs
Keyword(s):  
Stress Distribution ◽  
Stress Analysis ◽  
Analytical Model ◽  
Contact Stress ◽  
Sliding Wear ◽  
Flat Surface ◽  
Three Dimensional ◽  
Textured Surface ◽  
Two Dimensional ◽  
Contact Stress Distribution

In this paper, an analytical model for predicting the contact stress and wear distribution between a textured surface and a compliant flat is presented. The modeling formulation is based upon a two-dimensional stress analysis of the flat, and it allows the contact stress distribution to be found from the distribution of the sample deflection into the flat surface. The wear evolution was calculated from the contact stress.

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