FLANGED JOINT ANALYSIS: A SIMPLIFIED METHOD BASED ON ELASTIC INTERACTION

1993 ◽  
Vol 17 (2) ◽  
pp. 181-196 ◽  
Author(s):  
A. Bouzid ◽  
A. Chaaban

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.

2005 ◽  
Vol 127 (4) ◽  
pp. 414-422 ◽  
Author(s):  
Abdel-Hakim Bouzid ◽  
Akli Nechache

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.


2019 ◽  
Vol 13 (4) ◽  
pp. 6178-6194
Author(s):  
Widodo W. S. ◽  
R. Soenoko ◽  
M. A. Choiron ◽  
A. A. Sonief

Silicon rubber gaskets are commonly used in many industries for low pressure sealing conditions only. The research studies about the sealing performance improvement of a novel composite gasket made of the silicone rubber filled with ramie natural fibers in a bolted joint connection. In this research the sample of gasket consists of 4 different types of gasket i.e. a pure silicone rubber gasket and the silicone rubber composite gasket with 1, 2 and 3 layers of ramie fiber woven. The gaskets are tested using a water pressure testing equipment with a variation of internal fluid pressure and difference torques at 8 N.m, 12 N.m, 16 N.m and 20 N.m. The sealing performance is measured based on the maximum fluid pressure that can be hold by the gaskets before the fluid leaking occurred. The results show that the silicone rubber composite gaskets have better sealing performance comparing  with the pure silicone rubber gaskets where the silicon rubber gaskets capable to hold the internal fluid pressure until around 5 times rather  than pure silicon rubber gaskets (0.17 MPa comparing with 0.90 MPa). On the other hand the sealing performance of the composite gasket with 3 layers is almost 2 times better than the composite gasket with 1 layer and around 1.5 times better than the composite gasket with 2 layer of fiber woven.


1950 ◽  
Vol 17 (2) ◽  
pp. 169-179
Author(s):  
Irving Roberts

Abstract This paper consists of a study of the loading requirements of gaskets in bolted joints, with the object of developing a rational basis for design of such joints. Starting with an analysis of gasket conditions for tightness, the gasket factor m is defined, and its variation with initial gasket stress and gasket width is predicted. These trends are confirmed by a survey of the available literature data. In a bolted joint, gasket stress becomes a function of the elastic constants of the system. Equations are derived to predict gasket and bolt stresses resulting from application of internal fluid pressure, and typical elastic recovery curves for an asbestos gasket are presented. Consideration is given to the effect of gasket creep in a bolted joint, and to the problem of distribution of bolt load, for which an approximate theory is derived. On this basis, defects in the ASME Code are pointed out, and a tentative new design procedure is proposed. Finally, a summary of data which should be obtained for use with the new design procedure is given.


Author(s):  
Akli Nechache ◽  
Abdel-Hakim Bouzid

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.


Author(s):  
Masahiro Watanabe ◽  
Eiji Tachibana ◽  
Nobuyuki Kobayashi

This paper deals with the theoretical stability analysis of in-plane parametric vibrations of a curved bellows subjected to periodic internal fluid pressure excitation. The curved bellows studied in this paper are fixed at both ends rigidly, and are excited by the periodic internal fluid pressure. In the theoretical stability analysis, the governing equation of the curved bellows subjected to periodic internal fluid pressure excitation is derived as a Mathieu’s equation by using finite element method (FEM). Natural frequencies of the curved bellows are examined and stability maps are presented for in-plane parametric instability. It is found that the natural frequencies of the curved bellows decrease with increasing the static internal fluid pressure and buckling occurs due to high internal fluid pressure. It is also found that two types of parametric vibrations, longitudinal and transverse vibrations, occur to the curved bellows in-plane direction due to the periodic internal fluid pressure excitation. Moreover, effects of axis curvature on the parametric instability regions are examined theoretically.


2021 ◽  
Vol 10 (4) ◽  
pp. 1-27
Author(s):  
Shengxin Jia ◽  
Veronica J. Santos

The sense of touch is essential for locating buried objects when vision-based approaches are limited. We present an approach for tactile perception when sensorized robot fingertips are used to directly interact with granular media particles in teleoperated systems. We evaluate the effects of linear and nonlinear classifier model architectures and three tactile sensor modalities (vibration, internal fluid pressure, fingerpad deformation) on the accuracy of estimates of fingertip contact state. We propose an architecture called the Sparse-Fusion Recurrent Neural Network (SF-RNN) in which sparse features are autonomously extracted prior to fusing multimodal tactile data in a fully connected RNN input layer. The multimodal SF-RNN model achieved 98.7% test accuracy and was robust to modest variations in granular media type and particle size, fingertip orientation, fingertip speed, and object location. Fingerpad deformation was the most informative modality for haptic exploration within granular media while vibration and internal fluid pressure provided additional information with appropriate signal processing. We introduce a real-time visualization of tactile percepts for remote exploration by constructing a belief map that combines probabilistic contact state estimates and fingertip location. The belief map visualizes the probability of an object being buried in the search region and could be used for planning.


1983 ◽  
Vol 105 (3) ◽  
pp. 277-281 ◽  
Author(s):  
M. M. Bernitsas ◽  
T. Kokkinis

Open-ended tubular columns may buckle globally as Euler columns due to the action of internal fluid pressure even while they are in tension along their entire length. Hydraulic columns, marine drilling and production risers are, therefore, prone to such static instability. This paper explains this phenomenon, defines the critical riser length for which this instability may occur and provides graphs with values of the critical length which can readily be used for design purposes. Risers with nonmovable boundaries are considered; namely, hinged-hinged, clamped-hinged, hinged-clamped and clamped-clamped risers.


Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 797
Author(s):  
Hitesh Gowda Bettaswamy Bettaswamy Gowda ◽  
Ulrike Wallrabe

In this paper, we present a finite-element simulation of an adaptive piezoelectric fluid-membrane lens for which we modelled the fluid-structure interaction and resulting membrane deformation in COMSOL Multiphysics®. Our model shows the explicit coupling of the piezoelectric physics with the fluid dynamics physics to simulate the interaction between the piezoelectric and the fluid forces that contribute to the deformation of a flexible membrane in the adaptive lens. Furthermore, the simulation model is extended to describe the membrane deformation by additional fluid forces from the fluid thermal expansion. Subsequently, the simulation model is used to study the refractive power of the adaptive lens as a function of internal fluid pressure and analyze the effect of the fluid thermal expansion on the refractive power. Finally, the simulation results of the refractive power are compared to the experimental results at different actuation levels and temperatures validating the coupled COMSOL model very well. This is explicitly proven by explaining an observed positive drift of the refractive power at higher temperatures.


1963 ◽  
Vol 18 (4) ◽  
pp. 837-837 ◽  
Author(s):  
Javier Verdura ◽  
Robert J. White ◽  
Henry Kretchmer

A simplified method for recording the cerebrospinal fluid pressure in the dog is presented. It consists of introducing the polyethylene tube of a Rochester needle into the sub-arachnoid space at the level of the ventral atlanto-occipital joint. The advantages of this technique are: the dura mater is punctured under direct vision; a completely sealed fluid system results which permits direct inspection for cerebrospinal fluid leakage; and the animal may be placed in any anatomical position during the continuous monitoring of cerebrospinal fluid pressure. This method of measuring the cerebrospinal fluid pressure has been utilized in 30 canine experiments and has proven equally effective in recording cerebrospinal fluid pressures in monkeys. Submitted on December 21, 1962


1990 ◽  
Vol 112 (3) ◽  
pp. 284-290 ◽  
Author(s):  
D. D. Budny ◽  
F. J. Hatfield ◽  
D. C. Wiggert

The traditional approach to designing a piping system subject to internal dynamic pressure is to restrain the piping as much as possible, and the approximation made in the analysis is to assume no contribution of structural energy dissipation. To determine the validity of this concept and approximation, an experimental study of a piping system was performed to measure the influence of structural damping. A pipe system was designed with a loop that could be turned so that its natural frequency would match that of the contained liquid. It was discovered that a properly sized damper on the piping loop greatly accelerates the decay of the fluid pressure transient. The damper absorbs some energy from the piping, reducing the resulting rebound fluid pressure. When the loop is subjected to forced steady-state vibration, there is a fluid pressure response. The amplitude of that pressure can be reduced by installing an external damper: the stiffer the damper the more effective it is in reducing dynamic pressure.


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