Analytical Modeling of the Contact Stress With Nonlinear Gaskets

2001 ◽  
Vol 124 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Michel Derenne
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Room Temperature ◽  
Analytical Modeling ◽  
Design Rules ◽  
Nonlinear Mechanical ◽  
Leak Tightness ◽  
Gasket Material ◽  
Bolted Flange ◽  
Contact Stress Distribution

Gasket contact stress and its variation through the gasket width is caused by the rotation of the flange and has an influence on the leakage tightness behavior of bolted flange joints. The future implementation by the ASME of proposed design rules is based on new gasket constants obtained from the ROTT (room temperature tightness) tests conducted on rigid platens. The gasket contact stress distribution needs to be addressed for the purpose of better joint tightness predictions. This paper presents a comprehensive analytical method that predicts the gasket contact stress distribution taking into account the nonlinear mechanical behavior of the gasket material. Based on the flange rotational flexibility, the proposed analytical model that is implemented in the “SuperFlange” program is supported and validated by numerical FEA and experimental analyses on flange rotations, radial distribution of gasket contact stress, and joint leak tightness.

Contact Stress Evaluation of Nonlinear Gaskets Using Dual Kriging Interpolation

2004 ◽  
Vol 126 (4) ◽  
pp. 445-450 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Henri Champliaud
Keyword(s):  
Contact Stress ◽  
Nonlinear Modeling ◽  
Kriging Interpolation ◽  
Major Influence ◽  
Design Rules ◽  
Dual Kriging ◽  
Leak Tightness ◽  
Gasket Material ◽  
Floating Type ◽  
Contact Stress Distribution

The leakage behavior of bolted joint is very much dictated by the gasket contact stress. In particular, the non-uniform distribution of this stress in the radial direction caused by the flange rotational flexibility has a major influence on the leak tightness of some gasket types. The current ASME flange design rules and the new ASME proposed design rules addresses this effect by introducing the concept of gasket effective width for which the validity of the suggested values has not been verified. This paper presents a simple comprehensive analytical approach based on the dual kriging interpolation technique to predict the gasket contact stress distribution in floating type bolted joints. The kriging methodology is shown to be very efficient when nonlinear modeling such as gasket material mechanical behavior is involved. Together with the flange rotational flexibility, this technique implemented in the “SuperFlange” program is supported and validated by numerical FEA conducted on different flange sizes and gasket materials combinations.

On the Use of Dual Kriging Interpolation for the Evaluation of the Gasket Stress Distribution in Bolted Joints

2003 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Henri Champliaud
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Nonlinear Modeling ◽  
Bolted Joints ◽  
Kriging Interpolation ◽  
Major Influence ◽  
Design Rules ◽  
Dual Kriging ◽  
Gasket Material ◽  
Floating Type

The leakage behavior of bolted joint is very much dictated by the gasket contact stress. In particular, the non-uniform distribution of this stress in the radial direction caused by the flange rotational flexibility has a major influence on the leak tightness of some gasket types. The current ASME flange design rules and the new ASME proposed design rules addresses this effect by introducing the concept of gasket effective width for which the validity of the suggested values has not been verified. This paper presents a simple comprehensive analytical approach based on the dual kriging interpolation technique to predict the gasket contact stress distribution in floating type bolted joints. The kriging methodology is shown to be very efficient when nonlinear modeling such as gasket material mechanical behavior is involved. Together with the flange rotational flexibility, this technique implemented in the “SuperFlange” program is supported and validated by numerical FEA conducted on different flange sizes and gasket materials combinations.

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.

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.

Simple Model for Contact Stress of Strands Bent over Circular Saddles

2016 ◽  
Author(s):  
Sherif Mohareb ◽  
Arndt Goldack ◽  
Mike Schlaich
Keyword(s):  
Simple Model ◽  
Stress Distribution ◽  
Contact Force ◽  
Contact Stress ◽  
Flexural Rigidity ◽  
Strong Nonlinearity ◽  
Stress Distributions ◽  
Maximum Contact ◽  
Contact Stress Distribution ◽  
Peak Value

Cable-stayed and extra-dosed bridges are today widely used bridge types. Recently, saddles have been used to deviate strands of cables in the pylons. Up to now the mechanics of strands on saddles are not well understood. It was found, that typical longitudinal contact stress distributions between strand and saddle show a strong nonlinearity and a high peak value around the detachment point, where the strand meets the saddle. This paper presents a procedure to analyse the longitudinal contact stress distribution obtained by FEM calculations: This contact stress can be idealised as a constant contact stress according to the Barlow's formula and a contact force at the detachment point due to the flexural rigidity of the bent tension elements. An analytical model is provided to verify this contact force. Finally, a formula is presented to calculate the maximum contact stress. This study provides the basis for further research on saddle design and fatigue of strands.

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