2-D AUTOMATIC COMPOSITION OF NODAL VALUES FROM NUMERICAL MODEL USING SCRIPT PROGRAMMING

2013 ◽  
Vol 62 (1) ◽  
Author(s):  
Rudi Heriansyah
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Model ◽  
Finite Difference ◽  
Two Dimensional ◽  
Commercial Software ◽  
One Dimensional ◽  
Automatic Composition ◽  
The Individual ◽  
Individual Nodes

There are many commercial software to perform numerical modeling based on finite element (FEM) and finite difference (FDM) methods. It is often a requirement to the designer, that the values of the individual nodes in the numerical model are known. Usually, these softwares provide two methods to achieve this; firstly, by clicking directly onto the nodes of interest and secondly, by saving or exporting the whole nodal values to an external file. The former way is appropriate for models with small number of nodes, but as the number of nodes increases, it is no longer an efficient or effective way. Through the latter method, all nodal values are obtained, however the values are one-dimensional, and in some cases, only certain nodal values are required for presentation. In this paper, an algorithm for automatic composition of nodal values obtained from the second method mentioned above. The composed nodal values will be in two-dimensional form as this is the format used for uniform shaped model (square or rectangular). Since numerical softwares usually have facilities to save the data in a spreadsheet format, the proposed algorithm is implemented in this environment by using spreadsheet script programming.

Investigation of two-dimensional nonstationary processes of outflow a gas-saturated liquid from axisymmetric vessels

2012 ◽  
Vol 9 (1) ◽  
pp. 47-52
Author(s):  
R.Kh. Bolotnova ◽  
V.A. Buzina
Keyword(s):  
Comparative Analysis ◽  
Numerical Model ◽  
Liquid Mixture ◽  
Phase Model ◽  
Test Problems ◽  
Two Dimensional ◽  
Nonstationary Processes ◽  
Saturated Liquid ◽  
Two Phase ◽  
One Dimensional

The two-dimensional and two-phase model of the gas-liquid mixture is constructed. The validity of numerical model realization is justified by using a comparative analysis of test problems solution with one-dimensional calculations. The regularities of gas-saturated liquid outflow from axisymmetric vessels for different geometries are established.

scholarly journals Verification of the flexion and shear behavior in masonry panels accordance to ABNT NBR 15961-1 (2011), EN 1996-1-1 (2005) and ACI TMS 530 (2013)

2018 ◽  
Vol 11 (4) ◽  
pp. 673-685
Author(s):  
R. C. MATA ◽  
C. S. RAMOS ◽  
M. L. C. SILVA
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Design Criteria ◽  
Two Dimensional ◽  
Finite Element Software ◽  
Modelling Procedure ◽  
Increasing Trend ◽  
American Standard ◽  
Compression Level

Abstract This paper presents a numerical analysis of the mechanical behavior of structural masonry panels submitted to horizontal and vertical stresses. To evaluate the design process of these structures, the results obtained by the computer simulations were compared with the results determined by the design criteria of ABNT NBR 15961-1 (2011), ACI TMS 530 (2013) and EN 1996-1-1 (2005). The finite element software DIANA v.9.3 was used to simulate two-dimensional models with the simplified micro modelling procedure. The results obtained by the normative standards were more conservative than the results of the numerical model, as expected. With the increase of the pre-compression level, the computer simulation has demonstrated the increasing trend of the values of resistant forces, besides the change of the way of rupture of the panels. Among the three standards evaluated, the American Standard was the most conservative.

Numerical Methods of Higher-Order Accuracy for Diffusion- Convection Equations

1968 ◽  
Vol 8 (03) ◽  
pp. 293-303 ◽  
Author(s):  
H.S. Price ◽  
J.C. Cavendish ◽  
R.S. Varga
Keyword(s):  
Finite Difference ◽  
Boundary Conditions ◽  
Variational Methods ◽  
Miscible Displacement ◽  
Two Dimensional ◽  
Order Accuracy ◽  
One Dimensional ◽  
Finite Difference Approximations ◽  
Difference Approximations ◽  
Diffusion Convection

Abstract A numerical formulation of high order accuracy, based on variational methods, is proposed for the solution of multidimensional diffusion-convection-type equations. Accurate solutions are obtained without the difficulties that standard finite difference approximations present. In addition, tests show that accurate solutions of a one-dimensional problem can be obtained in the neighborhood of a sharp front without the need for a large number of calculations for the entire region of interest. Results using these variational methods are compared with several standard finite difference approximations and with a technique based on the method of characteristics. The variational methods are shown to yield higher accuracies in less computer time. Finally, it is indicated how one can use these attractive features of the variational methods for solving miscible displacement problems in two dimensions. Introduction The problem of finding suitable numerical approximations for equations describing the transport of heat or mass by diffusion and convection simultaneously has been of interest for some time. Equations of this type, which will be called diffusion-convection equations, arise in describing many diverse physical processes. Of particular interest here is the equation describing the process by which one miscible liquid displaces another liquid in a one-dimensional porous medium. The behavior of such a system is described by the following parabolic partial differential equation: (1) where the diffusivity is taken to be unity and c(x, t) represents a normalized concentration, i.e., c(x, t) satisfied 0 less than c(x, t) less than 1. Typical boundary conditions are given by ....................(2) Our interest in this apparently simple problem arises because accurate numerical approximations to this equation with the boundary conditions of Eq. 2 are as theoretically difficult to obtain as are accurate solutions for the general equations describing the behavior of two-dimensional miscible displacement. This is because the numerical solution for this simplified problem exhibits the two most important numerical difficulties associated with the more general problem: oscillations and undue numerical dispersion. Therefore, any solution technique that successfully solves Eq. 1, with boundary conditions of Eq. 2, would be excellent for calculating two-dimensional miscible displacement. Many authors have presented numerical methods for solving the simple diffusion-convection problem described by Eqs. 1 and 2. Peaceman and Rachford applied standard finite difference methods developed for transient heat flow problems. They observed approximate concentrations that oscillated about unity and attempted to eliminate these oscillations by "transfer of overshoot". SPEJ P. 293ˆ

Preliminary Ship Design Using One and Two-Dimensional Models

1999 ◽  
Vol 36 (02) ◽  
pp. 102-112
Author(s):  
Michael D. A. Mackney ◽  
Carl T. F. Ross
Keyword(s):  
Finite Element ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Two Dimensional ◽  
One Dimensional ◽  
Dimensional Finite Element ◽  
Dimensional Models ◽  
Support Conditions ◽  
The One ◽  
Three Dimensional Finite Element

Computational studies of hull-superstructure interaction were carried out using one-, two-and three-dimensional finite element analyses. Simplification of the original three-dimensional cases to one- and two-dimensional ones was undertaken to reduce the data preparation and computer solution times in an extensive parametric study. Both the one- and two-dimensional models were evaluated from numerical and experimental studies of the three-dimensional arrangements of hull and superstructure. One-dimensional analysis used a simple beam finite element with appropriately changed sections properties at stations where superstructures existed. Two-dimensional analysis used a four node, first order quadrilateral, isoparametric plane elasticity finite element, with a corresponding increase in the grid domain where the superstructure existed. Changes in the thickness property reflected deck stiffness. This model was essentially a multi-flanged beam with the shear webs representing the hull and superstructure sides, and the flanges representing the decks One-dimensional models consistently and uniformly underestimated the three-dimensional behaviour, but were fast to create and run. Two-dimensional models were also consistent in their assessment, and considerably closer in predicting the actual behaviours. These models took longer to create than the one-dimensional, but ran in very much less time than the refined three-dimensional finite element models Parametric insights were accomplished quickly and effectively with the simplest model and processor, but two-dimensional analyses achieved closer absolute measure of the displacement behaviours. Although only static analysis with simple loading and support conditions were presented, it is believed that similar benefits would be found for other loadings and support conditions. Other engineering components and structures may benefit from similarly judged simplification using one- and two-dimensional models to reduce the time and cost of preliminary design.

Numerical Modeling of a Nonlinear MEMS Membrane

2004 ◽  
Author(s):  
Owen I. Crabtree ◽  
Sinisa Dj. Mesarovic ◽  
Ismail Demir ◽  
Robert F. Richards ◽  
David F. Bahr ◽  
...  
Keyword(s):  
Residual Stress ◽  
Numerical Modeling ◽  
Numerical Model ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Empirical Data ◽  
Geometrically Nonlinear ◽  
Mems Device ◽  
The Finite Difference Method ◽  
Stress Layer

A numerical model is developed to understand the behavior of a laminated, piezoelectric, geometrically nonlinear MEMS device. The finite difference method is chosen, along with the Newmark technique to model the static and vibrational behavior. This technique is validated by comparison to empirical data. The developed model is exercised to understand and optimize the device by studying residual stress, layer thicknesses, and electrode sizes with the goal of reduction of fundamental frequency and increase of charge output.

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