Regular papers / Articles ordinaires A numerical approach for the static analysis of the body of pressurized dry gas holders

2003 ◽  
Vol 30 (2) ◽  
pp. 381-390
Author(s):  
L H You ◽  
J J Zhang ◽  
H B Wu ◽  
R B Sun
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Plane Deformation ◽  
Numerical Approach ◽  
Gas Pressure ◽  
The Body ◽  
The Finite Element Method ◽  
Out Of Plane ◽  
Plane Bending ◽  
Element Method

In this paper, a numerical method is developed to calculate deformations and stresses of the body of dry gas holders under gas pressure. The deformations of the wall plates are decomposed into out-of-plane bending and in-plane deformation. The out-of-plane bending of the wall plates is described by the theory of orthotropic plates and the in-plane deformation by the biharmonic equation of flat plates under plane stress. The theories of beam columns and beams are employed to analyze the columns and corridors, respectively. By considering compatibility conditions between the members and boundary conditions, equations for the determination of deformations and stresses of dry gas holders under gas pressure are obtained. Both the proposed approach and the finite element method are used to investigate the deformations and stresses of the body of a dry gas holder under gas pressure. The results from the proposed method agree with those from the finite element method. Because far fewer unknowns are involved, the proposed method is computationally more efficient than both the finite element method and the series method developed from the theory of stiffened plates.Key words: numerical approach, body of dry gas holders, gas pressure.

Flexibility of Trunnion Piping Elbows

1990 ◽  
Vol 112 (2) ◽  
pp. 184-187 ◽  
Author(s):  
G. D. Lewis ◽  
Y. J. Chao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Chemical Plants ◽  
The Finite Element Method ◽  
Flexibility Analysis ◽  
Piping Systems ◽  
Out Of Plane ◽  
Element Method

Trunnion piping elbows are commonly used in piping systems in power and chemical plants. The flexibility of the trunnion piping elbows is normally less than that of the plain piping elbows. In this paper, the finite element method is used to derive the in-plane and out-of-plane flexibility factors of trunnion piping elbows. The results can be easily adopted into the piping flexibility analysis.

Modelling of the Behaviour of Dynamical Gas Seals: Calculation with a Finite Element Method Implicitly Assuring the Continuity of Flow

1995 ◽  
Vol 209 (3) ◽  
pp. 195-201 ◽  
Author(s):  
P Hernandez ◽  
R Boudet
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Results ◽  
The Body ◽  
Dynamical Model ◽  
The Finite Element Method ◽  
Flow Through ◽  
Gas Seals ◽  
Stiffness And Damping ◽  
Element Method

The objective of this paper is to present a model of the behaviour of dynamical seals and the corresponding numerical results. These seals are used in the mechanism to realize partial sealing when the relative rotating speeds are too high for usual solutions. The studied seals mainly include two discs: one is attached to the shaft and the other to the body, the last one being pushed and the first being attached by springs. During operation, a gaseous film is created between the discs, preventing any contact. The control of the film thickness allows the leakage flow to be controlled. For the behaviour of such mechanisms, an analytical formulation of the problem is firstly presented. Then a geometrical and kinematical model having one degree of freedom is proposed to model the mechanism having two discs in relative rotation, one of which is spirally grooved. A dynamical model associated with the motion of the disc attached to the body has been developed and the mechanics of thin viscous films is used to study the behaviour of the gaseous film at the interface. Utilization of the finite element method in the mechanics of thin viscous films is introduced and a description of the elements used is presented. The influence of the groove's angle and the groove's depth is shown through numerical results concerning leakage mass flow through the mechanism and the loading capacity of the fluid film, as well as the coefficients of stiffness and damping associated with the dynamical model.

Attenuation Effects of a Single Deck Floating Roof in a Liquid Storage Tank

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Mohammad Ali Goudarzi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Analytical Solution ◽  
Plane Deformation ◽  
Fem Analysis ◽  
Geometrical Parameters ◽  
Empirical Formulas ◽  
Out Of Plane ◽  
Element Method

Liquid-roof interaction imposes a complicated distribution of out-of-plane deformation on the single-deck type floating roof (SDRF), which is the main source of considerable seismic stresses in floating roof. In this paper, an analytical solution for evaluating the dynamic interaction between the liquid and the floating roof is developed. Main physical and geometrical parameters are involved by the proposed analytical solution (PAS) for evaluating the seismic stresses of a single deck floating roof tanks (SDFR). The results of PAS are compared with the results of existing empirical formulas for various dimensions of SDRF tanks. In order to assess the validity of PAS for various sloshing wave height, a numerical model based on finite element method is established and the PAS results are compared with the finite element method (FEM) analysis results. The PAS predictions are in very good agreement with both the available empirical formula and the numerical model results.

Modeling of the impact of hold-down forces on the accuracy of the workpiece shape using the finite element method

2021 ◽  
pp. 9-20
Author(s):  
A.V. Zaitsev ◽  
A.N. Izosimov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cross Section ◽  
The Body ◽  
Machining Process ◽  
Mechanical Processing ◽  
The Finite Element Method ◽  
The Cross ◽  
The Impact ◽  
Element Method

In the article, the modeling of the impact of hold-down forces on the accuracy of the shape of the workpiece using the finite element method was carried out. The operation of mechanical processing (turning cut) of a workpiece of the body of rotation type on a milling machine with basing and fixing along the inner cylindrical surface of the workpiece is considered. The study was conducted for four different types of machine retaining devices used on machines of this group. A consistent description and illustration of the method of modeling the process of the impact of hold-down forces on the workpiece is made for each type of the device under consideration. The force constraints and effects imposed on the model are described and illustrated, the parameters of the finite element grid used in modeling are presented, the displacement profiles obtained in the modeling process and the stages of modeling the machining process are described, and the values of the largest deviations from the shape of the workpiece are determined. The results of the modeling are presented: a qualitative picture of the shape errors obtained as a result of mechanical processing — the values of the largest deviation from the roundness and the largest deviation from the cross-section profile of the workpiece to be processed, as well as the shape of the cutting obtained in the cross-section of the workpiece for each type of the devices under consideration. On the basis of the obtained results, estimates of the degree of accuracy of the shape and the relative geometric accuracy provided by the considered devices were made in accordance with GOST 24643–81. The conclusion is made about the suitability of using the considered variants of machine retaining devices for the proposed technological process according to the criterion of the provided accuracy of the shape of the processed surface. English version of the article is available at URL: https://panor.ru/articles/modeling-the-influence-of-the-fastening-forces-on-the-accuracy-of-the-workpiece-shape-using-the-finite-element-method/65043.html

Determination of Elastic Modulus and Poisson Ratio for Nanoporous Materials

2012 ◽  
Vol 466-467 ◽  
pp. 366-370
Author(s):  
Fue Han ◽  
Chang Qing Chen ◽  
Ya Peng Shen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Modulus ◽  
Poisson Ratio ◽  
Nanoporous Materials ◽  
The Finite Element Method ◽  
Out Of Plane ◽  
Element Method

Through the finite element method, the elastic modulus and Poisson ratio out of plane of the honeycomb nanoporous materials are obtained. In the end, the values are contrasted with the scale values. Results show that the values are same to the scale values.

scholarly journals Vibration Analysis of Collecting Electrodes by means of the Hybrid Finite Element Method

2014 ◽  
Vol 2014 ◽  
pp. 1-19 ◽  
Author(s):  
I. Adamiec-Wójcik ◽  
J. Awrejcewicz ◽  
A. Nowak ◽  
S. Wojciech
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electrostatic Precipitator ◽  
Equations Of Motion ◽  
The Body ◽  
The Finite Element Method ◽  
Hybrid Finite Element Method ◽  
Hybrid Finite Element ◽  
Rigid Finite Element Method ◽  
Element Method

The paper presents a hybrid finite element method of shell modeling in order to model collecting electrodes of electrostatic precipitators. The method uses the finite element method to reflect elastic features and the rigid finite element method in order to model mass features of the body. A model of dust removal systems of an electrostatic precipitator is presented. The system consists of two beams which are modeled by means of the rigid finite element method and a system of collecting shells modeled by means of the hybrid finite element method. The paper discusses both the procedure of deriving the equations of motion and the results of numerical simulations carried out in order to analyze vibrations of the whole system. Experimental verification of the model is also presented.

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