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.

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.

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.

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.

Mechanical Characteristics and Design of Bolted T-Shape Flange Joints Subjected to Tensile Loadings

2014 ◽  
Author(s):  
Shunichiro Sawa ◽  
Yuya Omiya ◽  
Mitsutoshi Ishimura ◽  
Toshiyuki Sawa
Keyword(s):  
Maximum Stress ◽  
Bending Moment ◽  
Tensile Loading ◽  
Theory Of Elasticity ◽  
Bolted Joints ◽  
Spring Constant ◽  
Load Factor ◽  
Two Dimensional ◽  
Bolted Joint ◽  
Dimensional Theory

Bolted joints have been widely used in mechanical structures. However, a design of bolted joints has been carried out empirically. In designing a bolted joint, it is necessary to know a ratio of increment Ft in axial bolt force to an external tensile loading W, that is, the load factor φ=Ft/W. In our previous paper, the new formulation for obtaining the value of the load factor φ for a bolted joint in which two hollow cylinders were clamped was proposed by introducing the tensile spring constant Kpt for clamped parts. Then, it is shown that the values of the load factor of bolted joint obtained from our formulation are in a fairly good agreement with the experimental values. In addition, the effect of the position where an external load is applied to the joint is significant on the value of the load factor. In the present paper, a method for obtaining the value of the load factor for bolted T-shape flange joints in which two T-shape flanges are clamped by two bolts and nuts under tensile loadings is demonstrated using two-dimensional theory of elasticity. In the analysis of the load factor φ, the compressive spring constant Kc for a hollow cylinder around the bolt hole is calculated. The value of the correction factor Kc′/Kpt is also analyzed using the two-dimensional theory of elasticity. When the external tensile loads are applied to the joints, the bolts are inclined and as the result, the bending moment occurs in the bolts. A method for analyzing the bending stress in the bolts is also demonstrated. In the numerical calculations, the distance C between the bolt position and the center of T-shape flange is varied and the effect of the distance C on the load factor is examined. For the validation of the analyses, calculations are also carried out. Experiments to measure the load factor and the maximum stress due to the bending moment occurred in the bolts were carried out. The numerical results of the load factor and the maximum stress in the bolts are fairly coincided with the experimental results. Furthermore, a design method for the joints is discussed, that is, how to determine the bolt position C, the bolt preload for the external tensile loading, how to choose the bolt strength.

Elastoplastic Frictional Contact Study on Interference Fits of Compressor

2011 ◽  
Vol 211-212 ◽  
pp. 535-539
Author(s):  
Ai Hua Liao
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Frictional Contact ◽  
Contact Problems ◽  
Boundary Problems ◽  
Interference Fit ◽  
Parametric Variational Principle ◽  
Design And Manufacturing ◽  
Contact Stress Distribution ◽  
Fit Tolerance

The impeller mounted onto the compressor shaft assembly via interference fit is one of the key components of a centrifugal compressor stage. A suitable fit tolerance needs to be considered in the structural design. A locomotive-type turbocharger compressor with 24 blades under combined centrifugal and interference-fit loading was considered in the numerical analysis. The FE parametric quadratic programming (PQP) method which was developed based on the parametric variational principle (PVP) was used for the analysis of stress distribution of 3D elastoplastic frictional contact of impeller-shaft sleeve-shaft. The solution of elastoplastic frictional contact problems belongs to the unspecified boundary problems where the interaction between two kinds of nonlinearities should occur. The effect of fit tolerance, rotational speed and the contact stress distribution on the contact stress was discussed in detail in the numerical computation. The study play a referenced role in deciding the proper fit tolerance and improving design and manufacturing technology of compressor impellers.

Bounds on the Maximum Contact Stress of an Indented Elastic Layer

1971 ◽  
Vol 38 (3) ◽  
pp. 608-614 ◽  
Author(s):  
Y. C. Pao ◽  
Ting-Shu Wu ◽  
Y. P. Chiu
Keyword(s):  
Half Space ◽  
Contact Stress ◽  
Elastic Layer ◽  
Theory Of Elasticity ◽  
Contact Conditions ◽  
Practical Applications ◽  
Method Of Solution ◽  
Elastic Layers ◽  
Maximum Contact ◽  
Contact Stress Distribution

This paper is concerned with the plane-strain problem of an elastic layer supported on a half-space foundation and indented by a cylinder. A study is presented of the effect of the contact condition at the layer-foundation interface on the contact stresses of the indented layer. For the general problem of elastic indenter or elastic foundation, the integral equations governing the contact stress distribution of the indented layer derived on the basis of two-dimensional theory of elasticity are given and a numerical method of solution is formulated. The limiting contact conditions at the layer-foundation interface are then investigated by considering two extreme cases, one with the indented layer in frictionless contact with the half space and the other with the indented layer rigidly adhered to the half space. Graphs of the bounds on the maximum normal stress occurring in indented elastic layers for the cases of rigid cylindrical indenter and rigid half-space foundation are obtained for possible practical applications. Some results of the elastic indenter problem are also presented and discussed.

Linear Tracking Response Measurements: Determining Effects of Wheel-Load Configurations

1997 ◽  
Vol 1570 (1) ◽  
pp. 1-9
Author(s):  
J. Groenendijk ◽  
C. H. Vogelzang ◽  
A. A. A. Molenaar ◽  
B. R. Mante ◽  
L. J. M. Dohmen
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Wheel Load ◽  
Strain Effects ◽  
Relative Strain ◽  
Extreme Load ◽  
Tracking Device ◽  
Tracking Response ◽  
Contact Stress Distribution ◽  
Load Conditions

The relative strain effects of 15 different load configurations were studied. Using the linear tracking device (LINTRACK) accelerated loading facility, two 5-year-old pavements of 0.15-m asphalt on sand (one virgin and one loaded with 4 million 75-kN wheel loads) were tested. All measured strains were converted to strain factors relative to a standard load (super-single tire, 50 kN, 0.70 MPa). The results were compared with earlier measurements and BISAR-calculated factors. The results on the loaded pavement showed markedly more variation than those on the unloaded pavement. Generally, the BISAR-calculated relative strain factors matched the measured values well for the super-single tire. Considerable difference occurred only in the most extreme load conditions. Nonuniform contact stress distribution can be the cause for this. The calculated relative strain factors for the dual tire configurations underestimated the measured values.

Sign in / Sign up

Export Citation Format

Share Document