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.

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.

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.

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.

Analytical Modeling of Bolted Flange Joints With Full Face Gaskets

2004 ◽  
Author(s):  
Hichem Galai ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Contact Stress ◽  
Analytical Modeling ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Low Leakage ◽  
Proposed Model ◽  
Asme Code ◽  
The Many ◽  
Full Face ◽  
Bolted Flange

Following the low leakage performance of flat face flanges, neither Appendix 2 nor Appendix Y of the ASME code which describes the design rules of flanges, are reliable to assess load changes when full face gaskets are used. The prediction of the tightness of these connections relies very much on the level of precision of the gasket contact stress during operation. However, determining this stress is complex, due to the many geometric and material parameters involved. This paper analyses the behaviour of bolted joints with full face gaskets. It presents an analytical approach to evaluate the operating flange rotation, gasket load and contact stress that may be used for leak prediction. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical FEA of different size flanges.

Effect of Creep of Non-Asbestos Sheet Gaskets at Elevated Temperature on Relaxation Behavior of Bolted Flange Joints

2011 ◽  
Author(s):  
Atsushi Yamaguchi ◽  
Takashi Honda ◽  
Masahiro Hagihara ◽  
Hirokazu Tsuji
Keyword(s):  
Elevated Temperature ◽  
Creep Strain ◽  
Creep Behavior ◽  
Elevated Temperatures ◽  
Relaxation Behavior ◽  
Test Conditions ◽  
Internal Fluid ◽  
Fiber Sheet ◽  
Ptfe Sheet ◽  
Bolted Flange

Gaskets in bolted flange joints experience creep when used for long periods of time. Since gaskets are often used at elevated temperatures, the clarification of their high-temperature creep behavior is essential. Relaxation of bolted flange joints is caused by creep in the gaskets, and may result in leakage of internal fluids. Therefore, the ability to predict relaxation in bolted flange joints due to the effects of creep in gaskets would allow the lifetime of the gaskets to be estimated and thus prevent leakage of internal fluid. In the present study, the creep behavior of non-asbestos sheet gaskets and the relaxation behavior of these gaskets in bolted flange joints at room/elevated temperature were investigated using four-inch flanges. The test conditions were 180 °C for 360 hours (approximately 2 weeks). The test samples were four types of non-asbestos sheet gaskets, two types of compressed fiber sheet gaskets and two types of PTFE sheet gaskets. The differences in creep behavior between the two types of compressed fiber sheet gaskets and between the two types of PTFE sheet gaskets were clarified. The creep strain at the end of the test was always larger than that just after reaching the test temperature for all gasket materials. On the other hand, the creep strain in the PTFE sheet gaskets just after reaching the elevated temperature was approximately equivalent to the total creep strain after the test has been completed. Thus, the creep behavior of each test gaskets was clarified under aging. In addition, the time for replacement of gaskets was estimated using the relaxation behavior in bolted flange joints by defining the time to reach the minimum design seating stress of the test gasket.

A New Approach to Model Bolted Flange Joints With Full Face Gaskets

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Hichem Galai
Keyword(s):  
Elastic Interaction ◽  
Bolted Joints ◽  
Element Analysis ◽  
New Approach ◽  
Flexibility Analysis ◽  
Load Change ◽  
Proposed Model ◽  
Numerical Finite Element ◽  
Full Face ◽  
Bolted Flange

The poor leakage performance of flanges with full face gaskets is attributed to the low reliability of the existing design methods, and in particular, their lack of assessing accurately the bolt and gasket load changes. The prediction of tightness of bolted joints relies very much on the level of precision of the gasket contact stress during operation. The accurate evaluation of this stress requires a flexibility analysis of the joint that includes the flange, gasket, and bolts, and the interaction between them. This paper analyzes the distribution of gasket stress and the load change in bolted joints with full face gaskets. It proposes a simple analytical approach capable of predicting flange rotation and bolt load change during operation. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical finite element analysis of different size flanges.

Numerical Simulation of the Assembly Process of Bolted Flange Joints Used in Rotating Machinery

2020 ◽  
Author(s):  
Linbo Zhu ◽  
Abdel-Hakim Bouzid ◽  
Jun Hong ◽  
Zhenming Shi
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Elastic Interaction ◽  
Rotating Machinery ◽  
Least Square ◽  
Bolted Joints ◽  
Fe Method ◽  
Element Analysis ◽  
Bolt Preload ◽  
Bolted Flange

Abstract Bolted joints are widely used to connect structural components in rotating machinery. However, the initial tightening of the bolts is a delicate operation because it is extremely difficult to achieve the target load and uniformity due to elastic interaction. The scatter in the bolt preload has a major impact on the concentricity and consequently the dynamic behavior of rotating machinery. The risk of failure due to vibration and fatigue under service loading becomes an issue. This paper treats the effect of elastic interaction on the eccentricity during the tightening of bolted joints of rotating machinery using finite element (FE) method. In this regard, a two-component bolted flange joint of a high pressure compressor (HPC) of an aero-engine is investigated. The component surface tolerances measured by Rotary Precision Instruments (RPI) are taken into account in the numerical simulation. A method is proposed to calculate the concentricity of components obtained from the radial runout data based on the Least Square method (LSM). The scatter in bolt preload under different interference fit, surfaces tolerance, initial preload, and tightening sequence are evaluated. Furthermore, the influence of these structures and tightening sequence parameters on the concentricity are investigated. The validity of the finite element analysis is supported by experimental tests conducted on scaled specimens of HPC. This study can provide guidance and enhance the dynamic performance of bolted joints for rotating machinery.

Bolted Flange Joints With Full Face Gaskets: An Analytical Approach Based on Flexibility

2005 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Hichem Galai
Keyword(s):  
Analytical Approach ◽  
Design Method ◽  
Elastic Interaction ◽  
Bolted Joints ◽  
Low Leakage ◽  
Load Change ◽  
Proposed Model ◽  
Asme Code ◽  
Full Face ◽  
Bolted Flange

The low leakage performance of flanges with full face gaskets is attributed to the reliability of the design method used in Appendix 2 and Appendix Y of the ASME code in assessing accurately the bolt and gasket load changes. The prediction of tightness of these bolted joints relies very much on the level of precision of the gasket contact stress during operation. The evaluation of this stress requires a flexibility analysis of the joint including the flange the gasket and bolt and the interaction between them. This paper analyses the distribution of gasket stress and the load change in bolted joints with full face gaskets. It proposes a simple analytical approach capable of predicting flange rotation and bolt load change during operation. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical FEA of different size flanges.

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.

Sign in / Sign up

Export Citation Format

Share Document