A Simple Method of the Load Factor Using a Circular Plate Theory for Bolted Pipe Flange Connections with Gaskets under Internal Pressure

2018 ◽  
Vol 2018 (0) ◽  
pp. YC2018-077
Author(s):  
Toshiyuki SAWA ◽  
Toshio Mabuchi ◽  
Koji SATO
Keyword(s):  
Internal Pressure ◽  
Circular Plate ◽  
Plate Theory ◽  
Load Factor ◽  
Simple Method

An Estimation of the Load Factor and Sealing Performance Evaluation for Bolted Pipe Flange Connections With Gaskets Under Internal Pressure

2017 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Koji Sato
Keyword(s):  
Internal Pressure ◽  
Plate Theory ◽  
Design Method ◽  
Spring Constant ◽  
Leak Rate ◽  
Load Factor ◽  
Real Rate ◽  
Simple Method ◽  
Gas Leakage ◽  
Bolt Preload

In designing bolted pipe flange connections with gaskets, It is necessary to know the actual residual gasket contact stress in the connections under internal pressure. However, the actual reduced gasket stress in the connection has not been sufficiently estimated. In estimating the actual residual contact gasket stress more precisely, it is needed to know the load factor (the ratio of an increment in axial bolt force to the axial force due to the internal pressure per bolt) of the connections with gaskets. The new formula for obtaining the load factor was proposed by one of the authors using the tensile spring constant Ktg and the compressive spring constant Kcg, while the spring constant of bolt-nut system is designated as Kt. In the present paper, for estimating the load factor of the connections with gaskets, the circular plate theory is applied for obtaining the values of Kcg and Ktg and then the load factor is obtained for pipe flanges specified JIS 10K flanges and ASME B 16.5 flanges. The obtained results are in a fairly good agreement with the FEM results. Using the obtained load factor for the connections, a design method is demonstrated taking account of the allowable leak rate. Using the residual contact gasket stress and the fundamental gasket leak rate, an amount of gas leakage is predicted. The predicted amount of gas leakage for 3” and 20” pipe flange connections is fairly coincided with the experimental results and the FEM results. In addition, a design method for determining the bolt preload for a give allowable real rate is demonstrated using the simple method for obtaining the load factor.

A Simple Calculation Method of the Load Factor and a Bolt Preload Determination Satisfying Allowable Leak Late for Bolted Pipe Flange Connections With Gaskets Subjected to Internal Pressure

2018 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Koji Sato ◽  
Toshio Mabuchi
Keyword(s):  
Internal Pressure ◽  
Circular Plate ◽  
Calculation Method ◽  
Plate Theory ◽  
Reaction Force ◽  
Simple Calculation ◽  
Couple Problem ◽  
Load Factor ◽  
Real Rate ◽  
Bolt Preload

In designing bolted pipe flange connections with gaskets under internal pressure, it is important to predict an actual residual contact gasket stress in the connections. For estimating the reduced gasket stress, it is needed how to know the load factor of the connections with gaskets. In the previous paper (2017PVP), for predicting the load factor of the connections with gaskets, a new model was proposed using a circular plate theory. However, the rigidity of the flange hub was assumed and it is necessary to improve the model for calculation. In the present paper, a simple and more accurate calculation method is proposed using a circular plate theory taking into account the reaction force distribution at the gasket interfaces and the effect of flange hub. In addition, the effect of the flange hub is analyzed as a couple problem between a cylindrical shell (hub) and a circular plate. The obtained results of the load factor in the connections are in a fairly good agreement with those obtained from FEM. In the numerical calculations, the values of the load factor for JIS 10K flange connections and ASME flange connections with compressed sheet and spiral wound gaskets (from 2” to 24”) are shown. Using the obtained load factor, the residual contact gasket stress and an amount of gas leakage are predicted. For verification of the simple calculation method for obtaining the load factor and FEM results, experiments to measure the load factor and the amount of the leakage were conducted for 24” connection. The calculated results are compared with the experimental method. In addition, an issue how to determine the bolt preload for satisfying a give allowable real rate is demonstrated.

Application of Plastic Region Bolt Tightening to Flange Joint Assembly: Behavior of Large Diameter Flange

2009 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Plastic Region ◽  
Load Factor ◽  
Past Study ◽  
Flange Joint ◽  
The Past ◽  
Sealing Performance ◽  
Assembly Behavior ◽  
Bolted Flange

In the past study the plastic region tightening has been applied to the bolted flange joint with smaller nominal diameter and its advantages have been demonstrated, however, behavior of the bolted flange joint with larger diameter is not investigated. Flange rotation of the bolted flange joint with large diameter increases when the internal pressure is applied. Gasket stress is not uniform and it may cause leak accident. So, it is necessary to investigate the behavior of the larger diameter flange. The present paper describes the behavior of bolted flange joint with large diameter under plastic region tightening. Firstly, API 20-inch flange joint tightened to the plastic region by bolt with a smaller diameter and superiority in the uniformity of the axial bolt force is demonstrated. And then the internal pressure is applied to the bolted flange joint and the behavior of the additional axial bolt force is demonstrated. The axial bolt force decreases with increasing the internal pressure, and the load factor is negative due to increasing of the flange rotation. However, the load factor of the bolted flange joint tightened to the plastic region by using the bolt with the smaller diameter approached zero. Using the bolts with smaller diameter is advantageous to the flange joint with the larger diamter, whose load factor is negative, to prevent the leakage. Additionally, the leak rate from the bolted flange joint is measured and the sufficient sealing performance is obtained.

A Simple Method for Elastic Analysis of Grillages

1968 ◽  
Vol 12 (02) ◽  
pp. 153-159
Author(s):  
Pin-Yu Chang
Keyword(s):  
Finite Element ◽  
Plate Theory ◽  
Computer Time ◽  
Design Tool ◽  
Matrix Transformations ◽  
Simple Method ◽  
Elastic Foundations ◽  
Beam Analysis ◽  
Order Of Magnitude ◽  
Desk Calculator

The theory of beams supported by elastic foundations has been shown to be particularly well-suited to the analysis of grillage beams [1, 2, 3[.2 This theory leads to a far more general formulation regarding the types of structures amenable to analysis than that offered by the orthotropic plate theory. As compared to the methods of finite element theory, the theory of beams supported by elastic foundations decreases the computer time by an order of magnitude, thus making the analysis particularly valuable as a design tool. This paper shows that the measurement of the grillage beam analysis based upon the elastic foundation concept can be further simplified by certain matrix transformations that uncouple the deflection equations. The problem has, in fact, been simplified to such an extent that many large grillages can be analyzed with the aid of a desk calculator. Whenever comparison with results obtained from finite element methods has been possible, it has been found that, for all practical purposes, complete correlation exists.

A simplified plate theory for vibration analysis of composite laminated sector, annular and circular plate

2019 ◽  
Vol 143 ◽  
pp. 106252 ◽  
Author(s):  
Hong Zhang ◽  
Rupeng Zhu ◽  
Dongyan Shi ◽  
Qingshan Wang
Keyword(s):  
Circular Plate ◽  
Vibration Analysis ◽  
Plate Theory

On the Existence of a Solution for a Solid Circular Plate Bilaterally Supported Along Two Antipodal Boundary Arcs and Loaded by a Central Transverse Concentrated Force

2000 ◽  
Vol 68 (5) ◽  
pp. 809-812 ◽  
Author(s):  
G. Monegato ◽  
A. Strozzi
Keyword(s):  
Circular Plate ◽  
Plate Theory ◽  
Reaction Force ◽  
Mechanical Analysis ◽  
Square Root ◽  
Existence Of A Solution ◽  
Concentrated Force ◽  
Boundary Constraints ◽  
Title Problem ◽  
The One

A purely flexural mechanical analysis is presented for a thin, solid, circular plate, deflected by a central transverse concentrated force, and bilaterally supported along two antipodal periphery arcs, the remaining part of the boundary being free. This problem is modeled in terms of a singular integral equation of the Prandtl type, which possesses a unique solution expressed in terms of a reaction force containing a factor exhibiting square root endpoint singularities. This solution is then shown not to respect the requested boundary constraints. It is therefore concluded that, within the framework of the purely flexural plate theory, the title problem cannot admit the weighted L2 solution here examined. It cannot, however, be excluded that a solution to the title problem exists, which possesses stronger endpoint singularities than those examined in this paper, or is of a more general form than the one considered here.

Bolt Load Changes Due to Internal Pressure in Gasketed Flange Connections

2003 ◽  
Author(s):  
Satoshi Nagata ◽  
Mitsuhiro Matsumoto ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Thrust Force ◽  
High Reliability ◽  
Constant Load ◽  
Point Of View ◽  
Load Factor ◽  
Test Results ◽  
Performance Point ◽  
Load Factors ◽  
Sealing Performance

Bolt load changes due to internal pressure are very important in order to evaluate the integrity of gasketed flange connections in the sealing performance point of view, because its gasket stress which dominates leak rate changes according to the bolt load changes. For establishing a connection possesses high reliability and sufficient integrity, it is necessary to clarify the mechanics ofgasketed flange connections. For this purpose, authors carried out experimental pressurizing tests for 3B and 20B gasketed flange connections clamped by various bolt preloads and measured the bolt load changes with increasing internal pressure up to 5MPa. Also a load factor, which is defined as the ratio of axial bolt force increment to pressure thrust force, was calculated using the test results. The test results indicate that 3B and 20B flange connections with the spiral wound gaskets have a constant load factors under sufficient initial clamping forces in assemble.

Semi-Active Control of Sound Radiated From an Elastic Circular Plate Integrated With Adaptive Tuned Vibration Absorbers

2016 ◽  
Author(s):  
Masoud Hemmatian ◽  
Ramin Sedaghati
Keyword(s):  
Circular Plate ◽  
Plate Theory ◽  
Integral Approach ◽  
Shear Mode ◽  
Transverse Displacement ◽  
Vibration Absorbers ◽  
Classical Plate Theory ◽  
Low Frequencies ◽  
Control Applications ◽  
Radiated Sound

While adaptive tuning of vibration absorbers (ATVA) have been widely studied for vibration control applications, limited studies have been done to explore their potential for noise control applications. This study aims to utilize magnetorheological elastomer (MRE)-based ATVA to control the radiated sound from an elastic plate excited by a plane wave especially at low frequencies. Radiated sound from a clamped circular plate integrated with MRE-based ATVA is analytically studied using classical plate theory. Rayleigh integral approach is, then, used to express the transmitted sound pressure in terms of the plate’s displacement modal amplitude. A MRE-based ATVA under shear mode is investigated. The semi-active Skyhook controller is proposed to attenuate the transverse displacement of the plate and subsequently reduce the radiated sound. The controller determines the current input to the electromagnet and tunes the MRE-based ATVA with the desired stiffness.

scholarly journals Nonlinear electromechanical analysis of axisymmetric thin circular plate based on flexoelectric theory

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Ji
Keyword(s):  
Circular Plate ◽  
Electromechanical Coupling ◽  
Plate Theory ◽  
Equilibrium Equations ◽  
Nonlinear Free Vibration ◽  
Flexoelectric Effect ◽  
Nonlinear Static ◽  
The Galerkin Method ◽  
Stiffening Effect ◽  
Plate Type

AbstractFlexoelectricity will dominate the electromechanical coupling of intelligent components in MEMS/NEMS due to its size-dependency. This paper focuses on investigating the flexoelectric responses of intelligent components of the circular plate type, which are commonly used in MEMS/NEMS. Utilizing Hamilton’s principle, the nonlinear flexoelectric circular plate model is presented by combining von Kármán plate theory and flexoelectric theory. The equilibrium equations and all boundary conditions are obtained and then discretized. The nonlinear static bending of the simply supported axisymmetric flexoelectric circular plate is investigated by combining DQM and iteration method. The distributions of dimensionless bending deflection and electric potential are analyzed under different loads. Moreover, the nonlinear free vibration behaviors are also investigated by combining the Galerkin method and Lindstedt–Poincaré Method. The flexoelectric effect and stiffening effect of strain gradient are revealed. This paper will be helpful to promote the application of flexoelectric intelligent components of the circular plate type, which are encountered commonly in engineering.

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