Analysis of Heat Flow Around Bolted Joints and Variations of Axial Bolt Force

2007 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura ◽  
Keiichi Shino
Keyword(s):  
Heat Flow ◽  
Internal Combustion Engines ◽  
Thermal Stresses ◽  
Thermal Contact ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Practical Applications ◽  
Computation Efficiency ◽  
Bolt Stress

A bolted joint is frequently used under thermal load in practical applications, such as pressure vessels, internal combustion engines, etc. In order to accurately evaluate the thermal stresses thus produced, the effects of thermal contact resistance at the interface and the heat flow through small gaps, which exist around the objective bolted joint, must be taken into account. In this paper, a numerical approach with high computation efficiency is proposed, where empirical equations for thermal contact coefficient and apparent thermal contact coefficient are incorporated into commercial engineering software. By conducting systematic three-dimensional FE analyses, it is quantitatively elucidated how the supplied heat flows through each part of a bolted joint and how the bolt stress varies with time. Bolted joints made of the materials with low thermal conductivity exhibit specific behaviors on the heat flow pattern around the bolted joint and the variations of axial bolt stress and bolt bending stress.

Analysis of Heat Flow Around Bolted Joints and Variations of Axial Bolt Force

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura ◽  
Keiichi Shino
Keyword(s):  
Heat Flow ◽  
Internal Combustion Engines ◽  
Thermal Stresses ◽  
Thermal Contact ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Bending Stress ◽  
Bolted Joint ◽  
Computation Efficiency ◽  
Bolt Stress

A bolted joint is widely used for the structures and machines subjected to thermal load, such as pressure vessels, internal combustion engines, brake disks, etc. In order to accurately evaluate the thermal stresses thus produced, the effect of thermal contact resistance at the interface and the heat flow through small gaps, which exist around the objective bolted joint, must be taken into account. In this paper, a numerical approach is proposed to solve the mechanical and thermal behaviors of bolted joints with high accuracy and computation efficiency, where empirical equations for thermal contact coefficient and apparent thermal contact coefficient are incorporated into commercial engineering software. By conducting systematic three-dimensional finite element analyses, it has been quantitatively elucidated how the supplied heat flows through each part of a bolted joint and how the axial bolt stress and bolt bending stress vary with time. It is concluded that bolted joints made of the materials with low thermal conductivity show specific heat flow patterns around the bolted joint and generate a large amount of variations in both axial bolt stress and bolt bending stress.

Finite Element Analysis of the Thermal and Mechanical Behaviors of Bolted Joint

2003 ◽  
Author(s):  
Toshimichi Fukuoka
Keyword(s):  
Finite Element ◽  
Heat Flow ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Thermal Contact ◽  
Numerical Procedure ◽  
Pressure Vessels ◽  
Element Formulation ◽  
Bolted Joint ◽  
Flow Through

Mechanical and thermal behaviors of the bolted joint subjected to thermal load are analyzed using axisymmetric FEM, where the effects of thermal contact resistance at the interface and heat flow through small gaps are taken into account in order to accurately evaluate the variations of bolt preloads. It is expected that the numerical procedure proposed here provides an effective means for estimating the strength of such critical structures as internal combustion engines, pressure vessels, steam and gas turbines, etc. An empirical equation that can compute the thermal contact coefficient at the interface composed of common engineering materials has been proposed in the previous paper. In this study, a simple equation for evaluating the amounts of heat flow through small gaps is shown by defining apparent thermal contact coefficient. A finite element approach has been established by incorporating the aforementioned thermal contact coefficients into the finite element formulation. By use of the FE code, it is shown that among various thermal properties, coefficient of linear expansion has dominant effects on the variations of bolt preloads. The validity of the numerical approach is demonstrated by experimentation.

Numerical Analysis of the Mechanical Behaviors of Bolted Joint Under Thermal Load

2000 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Quantuo Xu ◽  
Kentaro Yoshida
Keyword(s):  
Heat Flow ◽  
Contact Resistance ◽  
Gas Turbines ◽  
Thermal Load ◽  
Internal Combustion Engines ◽  
Thermal Contact ◽  
Pressure Vessels ◽  
Element Formulation ◽  
Bolted Joint ◽  
Flow Through

Abstract A bolted joint is frequently used in practical applications under thermal load, such as in internal combustion engines, steam and gas turbines, pressure vessels, etc. In order to accurately evaluate the thermal stresses thus produced, the effects of thermal contact resistance at the interface and the heat flow through small gaps, which exist around the bolted joint, must be taken into account. An empirical equation for the thermal contact co-efficient at the interface composed of similar materials was presented in a previous paper. In this study, the thermal contact coefficient is measured for the case of dissimilar materials using the same procedure. Further, a simple equation for apparent thermal contact coefficient is proposed to calculate the amount of heat flow through small gaps. By incorporating the effects of such contact resistance into the finite element formulation, thermal behaviors of a bolted joint with typical configuration are to be analyzed as elastic contact problems in the transient temperature field. It is shown that among various factors, coefficient of linear expansion has a dominant effect on the variations of bolt stress.

Finite Element Analysis of the Thermal and Mechanical Behaviors of a Bolted Joint

2005 ◽  
Vol 127 (4) ◽  
pp. 402-407 ◽  
Author(s):  
Toshimichi Fukuoka
Keyword(s):  
Heat Flow ◽  
Gas Turbines ◽  
Internal Combustion Engines ◽  
Thermal Contact ◽  
Numerical Procedure ◽  
Numerical Approach ◽  
Pressure Vessels ◽  
Bolted Joint ◽  
Mechanical Behaviors ◽  
Flow Through

Mechanical and thermal behaviors of the bolted joint subjected to thermal load are analyzed using axisymmetric FEM, where the effects of thermal contact resistance at the interface and heat flow through small gap are taken into account in order to accurately evaluate the variations of bolt preloads. It is expected that the numerical procedure proposed here provides an effective means for estimating the strength of such critical structures as pressure vessels, internal combustion engines, steam and gas turbines, etc. An experimental equation that can compute the thermal contact coefficient at the interface composed of common engineering materials has been proposed in the previous paper. In this study, a simple equation for evaluating the amount of heat flow through small gap is shown by defining apparent thermal contact coefficient. Accordingly, a numerical approach has been established, which can accurately analyze the thermal and mechanical behaviors of a bolted joint, by incorporating the two kinds of thermal contact coefficients into FE formulation. By use of the FE code thus developed, it is shown that only a slight difference in coefficients of linear expansion among the joint members significantly affects the variations of bolt preloads. The validity of the numerical approach is demonstrated by experimentation.

The Impact of Qualified Bolting Specialists on the Safe, Reliable Assembly and Operation of Bolted Flanged Connections

2015 ◽  
Author(s):  
A. Fitzgerald (Jerry) Waterland ◽  
David Lay ◽  
Michael Dodge
Keyword(s):  
Work Force ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Critical Area ◽  
Bolted Joint ◽  
Learning Program ◽  
Guideline Document ◽  
The Impact ◽  
Joint Assembly

Why do we certify welders but require no evidence of training or competence from those performing the critical bolted flanged joint assembly of pressure vessels and piping throughout the same industries? To remedy this situation ASME has recently released the first comprehensive standard in ASME PCC-1-2013 Appendix A that establishes uniform criteria, not just for the quality of the bolted joints but for the workers who assemble them. To support this critical training and qualification standard, ASME Training & Development has created a unique blended learning program for pipe fitters and mechanics to become Qualified Bolting Specialists (QBS), per the requirements outlined in PCC-1-2013 Appendix A. The purpose of this technical presentation is to explain the opportunities presented by this new standard and how industry can benefit from a better-trained work force in this critical area of bolted joint assembly. The authors have been integrally involved in the development of both the PCC-1 guideline document, and the ASME qualification program, and can authoritatively answer industry’s questions.

Stress Analysis and the Characteristics of T-Shape Bolted Joints Under Tensile Loadings

2005 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Seiichi Hamamoto
Keyword(s):  
Bending Moment ◽  
Theory Of Elasticity ◽  
Bolted Joints ◽  
Load Factor ◽  
Two Dimensional ◽  
Bolted Joint ◽  
Dimensional Theory ◽  
Matching Method ◽  
Point Matching ◽  
Bolt Stress

In designing a bolted joint, it is important to examine the interface stress distribution (clamping effect) and to estimate the load factor, that is the ratio of an additional axial bolt force to a load. In order to improve the clamping effect raised faces of the interface have been used. But these interfaces in bolted joints have been designed empirically and the theoretical grounds are not made clear. In the present paper, in the case of T-shaped flanges with raised faces the clamping effect is analyzed by a two-dimensional theory of elasticity and the point matching method. Then, the load factor is analyzed. Moreover, with the application of the load a bending moment is occurred in bolts and the stress is added due to this bending moment. The bending moment in the bolt is also analyzed. In order to verify these analyses experiments to measure the load factor and the maximum bolt stress were carried out. The values of the load factor and the load when interface start to separate are compared with those of the joints with flat-faces. The analytical results are in fairly good agreements with the experimental ones.

Dynamic Characteristics of Structure With Bolted Joint Considering Some Factors

2004 ◽  
Author(s):  
Shigeru Aoki
Keyword(s):  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Damping Ratio ◽  
Random Excitation ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Piping System ◽  
Bolted Joint ◽  
Earthquake Excitation ◽  
Applied Torque

Bolted joints are widely used for pressure vessels and piping system. Many studies on strength and stiffness of bolted joint are carried out. However, few studies on the dynamic characteristics of structure with bolted joint are carried out. The dynamic characteristics are important for design of structure subjected to earthquake excitations. In this paper, the effect of bolted joints on dynamic characteristics of structure is examined. First, the damping ratio and the natural frequency of specimens with some types of bolted joints are measured. Those are obtained for some factors, amplitude of excitation, applied torque. Obtained results are compared with those for the specimen without bolted joint. It is found that the damping ratio increases and the natural frequency becomes lower. Next, modeling of the bolted joint is presented. The bolted joint is modeled using additional mass, stiffness and damping elements. Finally, using model of bolted joint, response of the structure with bolted joint subjected to earthquake excitation is examined. Earthquake excitation is modeled as stationary random excitation. Mean square values of the response are obtained. Standard deviation of the acceleration response of the structure with bolted joint are lower than those without bolted joint.

Development of Modelling Guidelines for Stress Analysis of Pressure Vessel Bolted Closures

2010 ◽  
Author(s):  
A. Towse ◽  
A. Mills ◽  
D. Griffin ◽  
P. Hurrell ◽  
D. Rowe ◽  
...  
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Pressure Vessels ◽  
Service Performance ◽  
Bolted Joints ◽  
Model Complexity ◽  
Bolted Joint ◽  
Joint Models ◽  
Software And Hardware ◽  
Modelling Methods

This paper describes some of the outcomes of the development of finite element modelling guidelines for the stress analysis of bolted joints in pressure vessels and piping. The modelling methods originally developed at Rolls-Royce typically used 2D axisymmetric models as this was deemed adequate at the time. However, computing software and hardware improvements have subsequently been made which enable more realistic 3D bolted joint models to be solved where a greater level of geometric detail is required. For example the bolts, nuts and perforated flanges can now be represented more realistically reducing the degree of geometric abstraction that is required. Also, modern finite element codes such as ABAQUS and ANSYS now offer gasket elements which enable the initial compression, in-service performance and unloading of the joint to be modelled more realistically. Additionally, contact techniques can also be used to simulate the axial and radial distribution of thread load in the joint which will affect the stress distribution remote from the threaded region. Consequently, the modelling guidelines have been updated and provide guidance for stress engineers to decide which degree of model complexity is warranted.

Dynamic Characteristics of Structures With Bolted Joint

2002 ◽  
Author(s):  
Shigeru Aoki
Keyword(s):  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Random Vibration ◽  
Damping Ratio ◽  
Pressure Vessels ◽  
Bolted Joints ◽  
Simplified Model ◽  
Piping System ◽  
Bolted Joint ◽  
Acceleration Response

Bolted joints are widely used for pressure vessels and piping system. Many studies on strength of bolted joint are carried out. However, few studies on dynamic characteristics of structure with bolted joint are carried out. In this paper, the effect of bolted joints on dynamic characteristics of structure is examined. First, the damping ratio and the natural frequency of specimens with some types of bolted joints are measured. Obtained results are compared with those for the specimen without bolted joint. It is found that damping ratio increases and the natural frequency becomes lower. Next, the effect of bolted joint on random vibration response of structure using simplified model is examined. Standard deviation of acceleration response of structure with bolted joint is lower than that of structure without bolted joint.

The Penny-Shaped Interface Crack With Heat Flow, Part 1: Perfect Contact

1983 ◽  
Vol 50 (1) ◽  
pp. 29-36 ◽  
Author(s):  
C. J. Martin-Moran ◽  
J. R. Barber ◽  
M. Comninou
Keyword(s):  
Heat Flux ◽  
Heat Flow ◽  
Thermal Stresses ◽  
Contact Region ◽  
Thermal Contact ◽  
Dissimilar Materials ◽  
Contact Radius ◽  
Crack Face ◽  
Penny Shaped Crack ◽  
Shaped Crack

A solution is given for the thermal stresses due to a penny-shaped crack at the interface between dissimilar materials loaded in tension for the case where the heat flux is into the material with higher distortivity. Regions of separation and perfect thermal contact are developed at the crack faces. A harmonic potential function representation is used to reduce the problem to a three-part boundary value problem which is formulated as a pair of coupled Abel integral equations using the method of Green and Collins. These equations are further reduced to a single Fredholm equation which is solved numerically. Results are presented illustrating the effect of heat flux and applied tractions on the contact radius and the stress intensity factors for various combinations of material constants. The effect of heat flux is profoundly influenced by the relative signs of Dundurs constant β and a constant γ describing the mismatch of distortivities. If the more distortive material is also the more rigid, the contact region at the crack face is reduced by heat flow; otherwise it is increased. In the latter case, solutions involving separation are obtained even for applied compressive tractions if the latter is within a certain range. The solution also exhibits nonuniqueness in this range.

Sign in / Sign up

Export Citation Format

Share Document