Influence of Loading Rate on Deformation Behaviour and Sealing Performance of Spiral Wound Gasket in Flange Joint
01 Jan 2017-pp 83-93
TL;DR: In this paper, the deformation characteristic of spiral wound gasket along thickness direction is determined experimentally for different loading rates and the influence of different loading and unloading rates is emphasized on the sealing performance of flange joint using leakage pressure.
Abstract: Owing to increase in the demand for power, a number of power plants have been installed in the recent past. One of the vital components in these plants is gasketed flange joint. The behaviour of gasketed flange joint is highly dependent on the deformation characteristics of gasket material. In the present study, the deformation characteristic of spiral wound gasket along thickness direction is determined experimentally for different loading rates. Gasket has high nonlinearity under both loading and unloading, with hysteresis. Based on its characteristics, the flange joint is analysed to study its performance and leakage behaviour under static condition. 3D finite element model of flange joint is developed by considering the gasket as interface entity. Finite element analysis of flange joint is performed by including the nonlinear hysteretic behaviour of gasket, under different loading rate and frictional contact between joint members. The influence of different loading and unloading rates is emphasized on the sealing performance of flange joint using leakage pressure. The gasket deforms more when loaded at low rate. This phenomenon also affects the ability to withstand internal fluid without leakage. The maximum safe pressure without leakage increases, when gasket is loaded and unloaded at low rate.
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TL;DR: In this paper , a methodology is proposed to obtain the homogenised behaviour of heterogenous gasket by volume averaging the response from micromechanical analysis, which includes both loading and unloading characteristics of the gasket material.
Abstract: Gaskets are used as interfacing element between the mating surfaces, to seal the flange joint. The interfacing elements are usually subjected to compression during loading and relaxation during unloading. The unloading behaviour of the gasket material, when subjected to internal fluid pressure, controls the residual deformation in gasket. A methodology is proposed to obtain the homogenised behaviour of heterogenous gasket by volume averaging the response from micromechanical analysis. The response includes both loading and unloading characteristics of the gasket material. Here, the individual constituents’ characteristics in the spiral wound gasket is modelled using their respective elasto-plastic behaviour. But the unloading behaviour is more affected by the plastic properties. Therefore, the anisotropic Hill’s plastic parameters are evaluated by analysing the representative volume element of the gasket under different loading conditions. The compressive behaviour of the spiral wound gasket from homogenisation is compared with the experimental values for both loading and unloading conditions. An improved unloading behaviour is obtained using the proposed methodology.
1 citations
References
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TL;DR: In this article, a numerical approach is proposed to simulate the bolt-up process of a pipe-ange connection with a spiral wound gasket inserted, which can predict the scatter in bolt preloads and achieve uniform bolt preloading atthe completion of pipe flange assembly.
Abstract: It is well known that a large amount of scatter in bolt preloads is observed when boltingup a pipe flange connection, especially in the case of using a spiral wound gasket. In thisstudy, a numerical approach is proposed, which can simulate the bolt-up process of a pipeflange connection with a spiral wound gasket inserted. The numerical approach is de-signed so as to predict the scatter in bolt preloads and achieve uniform bolt preloads atthe completion of pipe flange assembly. To attain the foregoing purposes, the stress-strainrelationship of a spiral wound gasket, which shows highly nonlinear behavior, is identifiedwith a sixth-degree polynomial during loading and with an exponential equation duringunloading and reloading. Numerical analyses are conducted by three-dimensional FEM,in which a gasket is modeled as groups of nonlinear one-dimensional elements.@DOI: 10.1115/1.1613304#
49 citations
TL;DR: In this article, a three-dimensional nonlinear finite element model is developed for achieving a uniform clamp load in gasketed bolted joints, and the model is used for both multiple and single pass tightening patterns.
Abstract: A three-dimensional nonlinear finite element model is developed for achieving a uniform clamp load in gasketed bolted joints. The model is used for both multiple and single pass tightening patterns. Geometric nonlinearity of the gasket is taken into account and plastic model parameters are experimentally determined. The effect of the tightening pattern, gasket loading and unloading history, and the preload level is investigated. The validity of the FEA methodology is experimentally verified. This study helps improve the reliability of gasketed bolted joints by minimizing the bolt-to-bolt clamp load variation caused by elastic interaction among the various bolts in the joint during initial joint-bolt-up.
33 citations
TL;DR: In this article, two basically different types of MMC joints have to be distinguished: spiral wound gaskets (SWG) and flat face flanges and a gasket with a sealing element and distance ring (e.g. SWG with outer distance ring).
22 citations
20 citations
TL;DR: In this paper, a homogenization methodology is proposed to determine the material properties of spiral wound gaskets (SWGs) using finite element analysis through representative volume elements (RVE) of the Gaskets.
15 citations