Algorithm provides for automatic input data preparation for the analysis of continuous domains in the fields of structural analysis, heat transfer, and fluid mechanics. The computer program utilizes the natural coordinate systems concept and the finite element method for data generation

Akyuz, F.

English

NASA Technical Reports Server

September 1970	 Brief 70-10067 
NASA TECH BRIEF H 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Automatic Data Generation Scheme for Finite-Element

Method (FEDGE): Computer Program 
The problem: 
To devise a versatile and general purpose tool for 
input data preparation for the analysis of continuous 
domains in the fields of structural analysis, heat trans-
fer, or fluid mechanics. In the past, considerable 
attention has been given to automating the perform-
ance of such an analysis, but not to automating the 
preparation of input data. 
The solution: 
The algorithm used in the program is based on a 
suitable classification of the topological properties 
of complex geometrical configurations in one-, two-, 
or three-dimensional space. The algorithm provides 
for an automatic means of making continuous do-
mains of any form discrete by using the concept of 
natural coordinate systems. 
Depending on the complexity of the geometrical 
form and the diversity of the field quantities associated 
with different regions in the domain considered or 
on its boundary, the solution domain is divided into 
subdomains. Each subdomain has homogeneous field 
properties and reasonably convex form. The field 
quantities and geometrical properties associated with 
each region and the connectivity information of the 
adjacent subdomains are provided by the user as input. 
The generation of the mesh, computations of nodal 
coordinates, and the distribution of field properties 
to each finite element are automatically performed. 
The FEDGE program can be used for generation of 
input data for almost any structural analysis program 
using the finite-element method such as the SAMIS 
(Structural Analysis and Matrix Interpretive System) 
and ELAS (Equilibrium Problems of Linear Struc-
tures) programs, and also for data generation for 
solution of problems in other fields such as heat trans-
fer or fluid mechanics in which the finite-element tech-
nique is useful. FEDGE can also be used to generate 
input data for the solution of engineering and physics 
problems in which the finite-difference technique 
is used. As a general applicability rule, the natural 
coordinate system concept and the associated FEDGE 
program can be utilized for data generation in any 
field in which description of a domain with known 
boundary is required, especially where there is need 
for repeated use of such description. 
Notes: 
I. This program is written in FORTRAN 11(97%) 
and FAP (3%). The program was developed for the 
32K IBM 7094/44 DCS; however, it may be used 
in other systems that have the FORTRAN 11 com-
piler and FAP assembler. The program requires 10 
1/0 units. 
2. The SAMIS and ELAS programs are summarized 
in Tech Briefs 69-10093 and 68-10187, respectively. 
3. Inquiries concerning these programs should be 
directed to:
COSMIC 
Barrow Hall 
University of Georgia 
Athens, Georgia 30601 
Reference: B70-10067 
Patent status: 
No patent action is contemplated by NASA. 
Source: Fevzican Akyuzof 
Caltech/J PL 
under contract to 
NASA Pasadena Office 
(N PO- l 1069) 
Category 09 IdIkk
This document was prepared under the sponsorship of the National	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
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Automatic data generation scheme for finite-element method /FEDGE/ - Computer program

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