readme

FORTRAN编写的有限元教学程序,包括三角形单元.

Brief description of FEMSKI by Andre Cormeau

FEMSKI is a finite element program that was developed by the late professor Bruce Irons 
in the department of Civil Engineering at the University of Calgary. 
The goal in the development of FEMSKI was firstly to provide an instructor for teaching 
the finite element method (FEM) at the undergraduate level, and secondly to provide a 
documented entry point for graduate students wishing to develop further the theory for 
new elements, while providing an extensive level of diagnostics and error messages.

Bruce Irons was a pioneer and a world reknown scientist in the FEM world. 
Terms such as 'frontal solution', 'patch test', 'isoparametric elements', 
'serendipity family', 'hybrids' and 'semiloof shell' were borned out his fertile 
imagination and are still associated with him, more than a decade after his death.

The program should be used with the introductory text 'Finite Element Primer' by B.Irons 
and N.G.Shrive and the intricacies of the software are further explained in the text 
'Techniques of Finite Elements' by B.Irons and S.Ahmad.

The full source of the program is provided as is. 
It is written in standard FORTRAN77 in single precision (32 bits/floating point word). 
FEMSKI has quite of few intersting elements in its library (beams, shells and solids).
Some accuracy problems have been reported and are simply related to the inherent limited 
precision of the code. 
Users wishing to convert to double precision (64 bits/floating point word) should keep 
in mind that constants in executable statements and DATA statements should be converted 
to double precision. 
There is a minimal pre-processing capability. 
Post-processing is in the form of tabulated output. 
However, the programming phylosophy - data conversion to tables -> element stiffness -> 
assembly & solution -> back-substitution blends in perfectly with the frontal technique 
and is quite efficient. 
The program is quite difficult to understand for newcomers but well worth the effort 
for people wishing to get a better grasp of the finite element method.    


Original readme file:

CALGARY, MARCH 1987

FEMSKI IS SPLIT INTO 4 FORTRAN MODULES TO ALLOW COMPILATION ON A PC WITH
640k MEMORY. THE CODE IS COMPATIBLE WITH MICROSOFT FORTRAN77 V3.31 AND SHOULD
COMPILE WITH OLDER VERSIONS WITH ONLY MINOR CHANGES.

ALTHOUGH CONVERSION TO MS-FORTRAN IS COMPLETE, OUTPUT IS STILL IN 132 COLUMN
FORMAT AND IS AWKWARD TO READ ON STANDARD 80 COLUMN SCREENS. INPUT IS NOW ALL
FREE FORMAT BUT STILL REQUIRES THE LINES OF COMMENTS BETWEEN DATA LINES. THE
PROGRAM 'FEDATA' WILL GENERATE THESE BUT IS NOT PARTICULARLY USER-FRIENDLY AND
NEEDS TO BE USED IN CONJUNCTION WITH THE TEXT 'FINITE ELEMENT PRIMER' BY IRONS
AND SHRIVE.

TO COMPILE THE PROGRAM ON A PC, TYPE THE COMMAND "FEMCOMP". THIS RUNS A BATCH
FILE WHICH LOOKS FOR THE SOURCE FILES ON DRIVE A: AND A FORTRAN COMPILER
SOMEWHERE ON THE SYSTEM DEFAULT PATH.

PLEASE REPORT ANY DIFFICULTIES YOU HAVE IN GETTING THE PROGRAM RUNNING. ALSO, 
WE DO OUR BEST TO VERIFY CODING ERRORS REPORTED BY USERS AND TO MAKE THE 
NECESSARY UPDATES TO THE SOURCE.

GOOD LUCK!