Modeling of Viscoplastic Adhering Process by a Finite Element Technique

1993 ◽  
Vol 115 (1) ◽  
pp. 150-155 ◽  
Author(s):  
Y. Takahashi ◽  
T. Koguchi ◽  
K. Nishiguchi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Solid State ◽  
High Vacuum ◽  
The Finite Element Method ◽  
Intimate Contact ◽  
Solid State Bonding ◽  
Element Technique ◽  
Good Agreement ◽  
Element Method

The intimate contacting of rough surfaces in the solid state bonding of metals is modeled by a finite element method. The finite element method can be applied to the large deformation process of rate sensitive materials. The material used is an oxygen free copper. We treat only the case that the intimate contact is the rate controlling step in the solid state adhering process which can be realized under high vacuum and high temperature conditions for copper at least. The intimate contacting process is assumed to be produced by viscoplastic deformation after the initial local contact is made by instantaneous plastic deformation. The calculated results are in good agreement with the experimental ones. The model can predict the interfacial deformation during the solid state bonding carried out under high pressure conditions.

Elasto-plastic analysis of a rotating model conical turbine disc

1975 ◽  
Vol 10 (3) ◽  
pp. 167-171 ◽  
Author(s):  
F Ginesu ◽  
B Picasso ◽  
P Priolo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Limit Analysis ◽  
Point Of View ◽  
Complete Analysis ◽  
The Finite Element Method ◽  
Computational Simplicity ◽  
Rotating Shell ◽  
Good Agreement ◽  
Element Method

Results on the plastic collapse behaviour of an axisymmetric rotating shell, obtained by Limit Analysis and the Finite Element Method, are in good agreement with experimental data. The Finite Element Method, though computationally rather costly, permits, however, a more complete analysis of elasto-plastic behaviour. For the present case, the Limit Analysis has the advantage of greater computational simplicity and leads to a quite satisfactory forecast of collapse speed from the engineering point of view.

scholarly journals Modeling Electric Field and Potential Distribution of an Model of Insulator in Two Dimensions by the Finite Element Method

2018 ◽  
Vol 3 (1) ◽  
pp. 01
Author(s):  
Nassima M ziou ◽  
Hani Benguesmia ◽  
Hilal Rahali
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Potential Distribution ◽  
Two Dimensions ◽  
Comsol Multiphysics ◽  
The Finite Element Method ◽  
Good Agreement ◽  
Element Method

The electrical effects can be written by two magnitudes the field and the electrostatic potential, for the determination of the distribution of the field and the electric potential along the leakage distance of the polluted insulator, the comsol multiphysics software based on the finite element method will be used. The objective of this paper is the modeling electric field and potential distribution in Two Dimensions by the Finite Element Method on a model of insulator simulating the 1512L outdoor insulator used by the Algerian company of electricity and gas (SONELGAZ). This model is under different conductivity, applied voltage, position of clean layer and width of clean layer. The computer simulations are carried out by using the COMSOL multiphysics software. This paper describes how Comsol Multiphysics have been used for modeling of the insulator using electrostatic 2D simulations in the AC/DC module. Numerical results showed a good agreement.

The Finite-Element Method—Part II

1989 ◽  
Author(s):  
Shiro Kobayashi ◽  
Soo-Ik Oh ◽  
Taylan Altan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Integration ◽  
Gaussian Quadrature ◽  
The Finite Element Method ◽  
Gaussian Quadrature Formula ◽  
Stiffness Matrices ◽  
Minimum Number ◽  
Element Technique ◽  
Element Method

Numerical integration is an important part of the finite-element technique. As seen in Section 6.5 of Chap. 6, volume integrations as well as surface integrations should be carried out in order to represent the elemental stiffness equations in a simple matrix form. In deriving the variational principle, it is implicitly assumed that these integrations are exact. However, exact integrations of the terms included in the element matrices are not always possible. In the finite-element method, further approximations are made in the procedure for integration, which is summarized in this section. Numerical integration requires, in general, that the integrand be evaluated at a finite number of points, called Integration points, within the integration limits. The number of integration points can be reduced, while achieving the same degree of accuracy, by determining the locations of integration points selectively. In evaluating integration in the stiffness matrices, it is necessary to use an integration formula that requires the least number of integrand evaluations. Since the Gaussian quadrature is known to require the minimum number of integration points, we use the Gaussian quadrature formula almost exclusively to carry out the numerical integrations.

A Finite-Element Method for Through Flow Calculations in Turbomachines

1976 ◽  
Vol 98 (3) ◽  
pp. 403-414 ◽  
Author(s):  
Ch. Hirsch ◽  
G. Warzee
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Axisymmetric Flow ◽  
Axial Flow ◽  
The Finite Element Method ◽  
Flow Equations ◽  
Through Flow ◽  
Method Of Solution ◽  
Element Technique ◽  
Element Method

A new method for the numerical solution of the meridional through-flow equations in an axial flow machine is presented based on the finite-element method. A rigorous derivation of the pitch-averaged flow equations is presented and the assumption of axisymmetric flow leads, with the introduction of a stream function, to the equation to be solved. A description is given of the finite-element technique which is applied in this problem. The method of solution allows the calculation of transonic stages. Numerical results are compared with experimental data and show very satisfactory agreement. This method appears, therefore, to compare very favorably with the other methods used up to now. Although the present results pertain to axial flow machines, the method is easily applicable to radial flow machines as well and the way of solution for this case is indicated.

Study on Hydraulic Deep Drawing of Square Cups

2014 ◽  
Vol 626 ◽  
pp. 334-339
Author(s):  
Te Fu Huang ◽  
Hsin Yi Hsien ◽  
Yan Jia Chen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Deep Drawing ◽  
Thickness Distribution ◽  
The Finite Element Method ◽  
Experimental Apparatus ◽  
Punch Load ◽  
Simulation Results ◽  
Good Agreement ◽  
Element Method

The friction holding effect and the friction reducing effect occurring during Hydraulic Deep Drawing and the pre-bulging resulting in more plastic deformation on products are applied on sheet hydro-forming. For Hydraulic Deep Drawing of a square cup, the thickness distribution and the relation between the height and the pressure of pre-bulging are simulated with SPCC steels as the specimen by the finite element method. An experimental apparatus of sheet hydro-forming has been constructed to carry out the hydraulic deep drawing experiments of square cups. Experimental thickness distribution and punch load are compared with simulation results. Good agreement was found. The flow patterns of the circular and square blanks with the condition of being firmly pressed against the punch observed from the experiments are in agreement with the predicted results.Keywords:Hydraulic Deep Drawing, sheet hydro-forming, finite element method

scholarly journals Analysis of Spiral-Grooved Gas Journal Bearings by the Narrow-Groove Theory and the Finite Element Method At Large Eccentricities

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Elia Iseli ◽  
Eliott Guenat ◽  
Roger Tresch ◽  
Jürg Schiffmann
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Pressure ◽  
Journal Bearings ◽  
The Finite Element Method ◽  
Pressure Profiles ◽  
Stability Maps ◽  
Time Periodic ◽  
Good Agreement ◽  
Element Method

Abstract A finite groove approach (FGA), based on the finite element method (FEM), is used for analyzing the static and dynamic behavior of spiral-grooved aerodynamic journal bearings at different eccentricities, number of grooves, and compressibility numbers. The results of the FGA are compared with the narrow-groove theory (NGT) solutions. For the rotating-groove case, a novel time-periodic solution method is presented for computing the quasi-steady-state and dynamic pressure profiles. The new method offers the advantage of avoiding time-consuming transient integration, while resolving a finite number of grooves. The static and dynamic solutions of the NGT and FGA approach are compared, and they show good agreement, even at large eccentricities (ε=0.8) and high compressibility numbers (Λ = 40). Stability maps at different eccentricities are presented. At certain operation points, a stability decrease toward larger eccentricities is observed. The largest stability deviations of the NGT from the FGA solutions occur at large groove angle, low number of grooves, and large compressibility numbers.

The Stress of Sliding Vanes in a Rotary Compressor

2005 ◽  
Author(s):  
Yuan Mao Huang ◽  
Chien Liang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Computer Program ◽  
Rotary Compressor ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Good Agreement ◽  
Cover Plates ◽  
Element Method

A rotary sliding vane compressor was redesigned with extended rods on both edges of each vane and guide slots on both cover plates to improve its performance. The governing equations were derived to obtain loads acting on vanes and the stress of vanes. The finite element method is used with a generated computer program to determine the stress of vanes based on the calculated loads and the measured loads acting on the vanes. The results were compared and show good agreement with those obtained by using an existing software IDEAS.

Experimental and Finite Element Characterization of the Crippling Failure of Composite Stiffeners

2006 ◽  
Vol 326-328 ◽  
pp. 1773-1776
Author(s):  
Jin Hwe Kweon ◽  
Sang Min Choi ◽  
Hee Jin Son ◽  
Ji Young Choi ◽  
Jin Ho Choi ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Progressive Failure ◽  
Local Buckling ◽  
Equilibrium Path ◽  
The Finite Element Method ◽  
Progressive Failure Analysis ◽  
Good Agreement ◽  
Element Method

Progressive failure analysis based on the complete unloading method was conducted to investigate the crippling failure of carbon/epoxy composite stiffeners under axial compression. A modified arc-length algorithm was incorporated into a nonlinear finite element method to trace the equilibrium path after local buckling. For the validation of the finite element method, several carbon/epoxy Z-section stiffeners were tested in compression. The finite element results on the buckling and crippling stresses showed good agreement with the experimental results.

Free Vibration of Blade Packets

1977 ◽  
Vol 19 (1) ◽  
pp. 13-21 ◽  
Author(s):  
J. Thomas ◽  
H. T. Belek
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Free Vibration ◽  
Flexural Rigidity ◽  
Vibration Characteristics ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Reasonable Accuracy ◽  
Good Agreement ◽  
Element Method

The free-vibration characteristics of shrouded blade packets are studied using the finite-element method. The effects of various weight ratios, flexural rigidity ratios and length ratios between the blades and shrouds on the frequencies of vibration of the blade packet are investigated. It is shown that the vibration characteristics of a multibladed packet can be predicted with reasonable accuracy from the inference diagram of a two-bladed packet. The theory developed can be easily adapted for more complex blade packet configurations. The results presented for the frequencies of vibration are compared with experimental results and show good agreement with those of other investigators.

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