The Determination of Load Changes in Bolted Gasketed Joints Subjected to Elevated Temperature

2003 ◽  
Author(s):  
Akli Nechache ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Elevated Temperature ◽  
Operating Temperature ◽  
Interaction Model ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Analytical Models ◽  
Cover Plate ◽  
Thermally Induced ◽  
Internal Fluid

The tightness of bolted flanged joints subjected to elevated temperature is not properly addressed by flange design codes. The development of an analytical method based on the flexibility of the different joint components and their elastic interaction could serve as a powerful tool for elevated temperature flange designs. This paper addresses the effect of the internal fluid operating temperature on the variation of the bolt load and consequently on the gasket stress in bolted joints. The theoretical analysis used to predict the gasket load variation as a result of a temperature change is outlined. It details the analytical basis of the elastic interaction model and the thermally induced deflections that are used to evaluate the load changes. Two flange joint type configurations are treated; a joint with identical pair of flanges and a joint with a cover plate. The analytical models are validated and verified by comparison to finite element results.

An Analytical Solution for Evaluating Gasket Stress Change in Bolted Flange Connections Subjected to High Temperature Loading

2005 ◽  
Vol 127 (4) ◽  
pp. 414-422 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Akli Nechache
Keyword(s):  
Elevated Temperature ◽  
Operating Temperature ◽  
Interaction Model ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Analytical Models ◽  
Cover Plate ◽  
Thermally Induced ◽  
Internal Fluid ◽  
Bolted Flange

The tightness of bolted flanged joints subjected to elevated temperature is not properly addressed by flange design codes. The development of an analytical method based on the flexibility of the different joint components and their elastic interaction could serve as a powerful tool for elevated temperature flange designs. This paper addresses the effect of the internal fluid operating temperature on the variation of the bolt load and consequently on the gasket stress in bolted joints. The theoretical analysis used to predict the gasket load variation as a result of unequal radial and axial thermal expansion of the joint elements is outlined. It details the analytical basis of the elastic interaction model and the thermally induced deflections that are used to evaluate the load changes. Two flange joint type configurations are treated: a joint with identical pair of flanges and a joint with a cover plate. The analytical models are validated and verified by comparison to finite element results.

Thermally Induced Deflections in Bolted Flanged Connections

2005 ◽  
Vol 127 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Akli Nechache
Keyword(s):  
Thermal Effects ◽  
Operating Temperature ◽  
Theoretical Models ◽  
Cover Plate ◽  
Joint Analysis ◽  
Temperature Profiles ◽  
Thermally Induced ◽  
Effects Of Temperature ◽  
Bolted Flange

Pressure vessel joints operating at high temperature are often very difficult to seal. The existing flange design methods do not address thermal effects other than the variation of flange material mechanical properties with temperature. It is possible to include the effects of temperature loading in joint analysis, however, presently very few guidelines exist for this type of analysis. This paper outlines the theoretical analysis used for the determination of the steady state operating temperature and deflections in bolted flange joints. It details the theoretical equations necessary to predict the temperature profiles and thermal expansion difference between the joint components necessary for the evaluation of the load redistribution for the two cases of a flange pair and a flange with a cover plate. The results from the theoretical models are verified by comparison to finite element results.

A New Approach for Determining Joint Stiffness of Bolted Joints

2014 ◽  
Vol 670-671 ◽  
pp. 1041-1044 ◽  
Author(s):  
Xi Wang Wang ◽  
Xiao Yang Li ◽  
Lin Lin Zhang ◽  
Xiao Guang Wang
Keyword(s):  
Accurate Determination ◽  
Joint Stiffness ◽  
Fatigue Loading ◽  
Bolted Joints ◽  
Analytical Models ◽  
Bolted Connection ◽  
New Approach ◽  
Axisymmetric Model ◽  
Force Equilibrium

Joint member stiffness in a bolted connection directly influence the safety of a design in regard to both static and fatigue loading as well as in the prevention of separation in the connection. Thus, the accurate determination of the stiffness is of extreme importance to predict the behavior of bolted assemblies. In this paper, An analytical 3D axisymmetric model of bolted joints is proposed to obtain the joint stiffness of Bolted Joints. Considering many different analytical models have been proposed to calculate the joint stiffness, the expression based force equilibrium can be a easy way to choose the best expression for the joint stiffness as a judgment criteria.

Influence of Elevated Temperature on the Acoustic Emission Evaluation of FRP Vessels Through Internal Fluid Pressure Tests

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Guillermo Ramirez ◽  
Paul H. Ziehl ◽  
Timothy J. Fowler
Keyword(s):  
Acoustic Emission ◽  
Elevated Temperature ◽  
Operating Temperature ◽  
Fluid Pressure ◽  
Pressure Vessels ◽  
The Body ◽  
Emission Testing ◽  
Internal Fluid ◽  
Asme Code ◽  
Acoustic Emission Testing

A research program evaluating the effect of elevated temperature in the acoustic emission testing of fiberglass vessels was completed recently. The program aimed at evaluating the current ASME provisions that require acoustic emission testing for Class II vessels be carried out at operating temperature in the event that the operating temperature exceeds 49°C (120°F). Lack of data from fiber reinforced polymer vessels and/or components that have been subjected to acoustic emission evaluation at elevated temperature has resulted in speculation regarding the appropriateness of conducting the acoustic emission evaluation at elevated temperature. To address these issues, an experimental investigation was conducted on representative coupon specimens and pressurized cylindrical specimens at differing temperatures. The results from the coupon tests were presented in a previous publication. This paper will present the results of the cylindrical specimens and compare them to the coupon specimens drawing the final conclusions from the overall results of the program. The results from this study resulted in changes in the body of the ASME code for testing pressure vessels with acoustic emission at temperature.

FLANGED JOINT ANALYSIS: A SIMPLIFIED METHOD BASED ON ELASTIC INTERACTION

1993 ◽  
Vol 17 (2) ◽  
pp. 181-196 ◽  
Author(s):  
A. Bouzid ◽  
A. Chaaban
Keyword(s):  
Fluid Pressure ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Joint Analysis ◽  
Simple Analytical Model ◽  
Good Design ◽  
Sealing Performance ◽  
Internal Fluid ◽  
Simplified Method ◽  
Joint Behaviour

Structurally sound bolted joints often fail due to loss of tightness. This is because the clamping load is affected by the application of the internal fluid pressure. A good design technique should therefore encompass most aspects of joint behaviour and produce efficient sealing performance within the clearly defined limits of the method used. This paper presents a simple analytical model based on an extension of the Taylor Forge approach taking into account flange rotation, flexibility of both the gasket and the bolts and, when applicable, the stiffness of the end closure. Examples will be discussed based on experimentally determined gasket properties.

The Stresses in Fusion Joints

1933 ◽  
Vol 124 (1) ◽  
pp. 601-643
Author(s):  
E. G. Coker ◽  
R. Levi ◽  
R. Russell
Keyword(s):  
Stress Distribution ◽  
Theoretical Analysis ◽  
Weld Metal ◽  
Plane Stress ◽  
Bolted Joints ◽  
The Other ◽  
Cover Plate ◽  
Great Range ◽  
Maximum Stresses

Modern use of fusion joints instead of riveted or bolted connexions has produced a variety of new forms which offer numerous fields of inquiry covering a great range of problems. One set of problems relates to stress distribution directed more especially to the determination of the maximum stresses in fusion joints. This is almost entirely an experimental matter, since nearly all such joints have discontinuities imposed by practical necessities which render them insoluble by theoretical analysis, while little or no help can be gained from our existing knowledge and long experience of riveted and bolted joints on account of their essentially different nature. The present inquiry deals with problems of plane stress distribution in which models are used for measuring the stress at any point required by photo-elastic means, and in the first instance some typical butt welds of an unsymmetrical type are analysed experimentally. Other ways of connecting plates in line are then considered in which a joint is made by a lenticular section of weld metal on one side and a cover plate on the other, the ends of the latter being joined to the main plates by triangular sections of fusion metal. When the gap between the two main plates is sufficient the lenticular section of metal may be replaced by a pair of triangular fillets binding the inner ends of the plates to the cover strap, and this form is also dealt with. The effects of triangular fillets of lesser height than the butt straps and of corresponding fillets of curved quadrantal form are also examined with reference to a double butt strap joint. The paper concludes with a brief summary of the main results afforded by the experimental analysis.

Assessment of Sylphons Lifetime

2008 ◽  
Vol 59 (5) ◽  
pp. 605-610
Author(s):  
Alexandru Pupazescu ◽  
Stefan Minoiu ◽  
Constantin Manea
Keyword(s):  
Elevated Temperature ◽  
Strain Distribution ◽  
Accurate Determination ◽  
Multiaxial Fatigue ◽  
Tensile Curve

The paper contains an assessment of the sylphons lifetime for multiaxial fatigue. Three criteria were used two based on s � N diagram and one based on energy. For a more accurate determination of the sylphons lifetime the stress and the strain distribution been determined using FEM, the tensile curve of the steel W 4541 at elevated temperature.

Accurate Evaluation of Bolt and Clamped Members Stiffnesses Of Bolted Joints

2021 ◽  
Author(s):  
Rashique Iftekhar Rousseau ◽  
Abdel-Hakim Bouzid ◽  
Zijian Zhao
Keyword(s):  
Finite Element ◽  
Joint Stiffness ◽  
Element Model ◽  
Fe Analysis ◽  
Bolted Joints ◽  
Analytical Models ◽  
Fe Modeling ◽  
Bolted Joint ◽  
A New Technique ◽  
External Loads

Abstract The axial stiffnesses of the bolt and clamped members of bolted joints are of great importance when considering their integrity and capacity to withstand external loads and resist relaxation due to creep. There are many techniques to calculate the stiffnesses of the joint elements using finite element (FE) modeling, but most of them are based on the displacement of nodes that are selected arbitrarily; therefore, leading to inaccurate values of joint stiffness. This work suggests a new method to estimate the stiffnesses of the bolt and clamped members using FE analysis and compares the results with the FE methods developed earlier and also with the existing analytical models. A new methodology including an axisymmetric finite element model of the bolted joint is proposed in which the bolts of different sizes ranging from M6 to M36 are considered for the analysis to generalize the proposed approach. The equivalent bolt length that includes the contribution of the thickness of the bolt head and the bolt nominal diameter to the bolt stiffness is carefully investigated. An equivalent bolt length that accounts for the flexibility of the bolt head is proposed in the calculation of the bolt stiffness and a new technique to accurately determine the stiffness of clamped members are detailed.

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