FELIPE Online Manual:
the 'Main engines'


Basic-level 'main engines'

 *  POISS.FOR - Poisson equation
 *  ELAST.FOR - 2D elasticity
 *  FRAME.FOR - Beams and frames

Advanced-level 'main engines'

The main features of each program, including the solution algorithm(s) used, are summarised in the Introduction chapter of this manual.

All the above programs, with one exception, need to be linked to the file FELSB.FOR containing input/output and other common subroutines. The exception is ELADV.FOR, which is completely self-standing. These programs should all be compiled in double precision (use the /dreal option in the Salford compiler). Remeber to compile FELSB.FOR with this option also -- unpredictable errors at run-time will be generated if a `main engine' compiled in double precision calls a subroutine in FELSB.FOR which is compiled in single precision, as the double-precision arguments of the call will not be mapped properly onto the subroutine's arguments.

The Appendix to the full manual summarises the finite element theory used in each program; a full description is beyond the scope of the manual, and the user is referred to the standard texts such as Zienkiewicz and Taylor (see Chapter 10). In this chapter some programming and data input aspects of the `main engines' will be discussed. Note that the different algorithms for global matrix storage and solution, are described in the following Chapter and will not be covered below.

The Poisson program POISS.FOR

View the source code!

Program operation

A number of secondary subroutines used by the Poisson main program POISS.FOR are contained in the source code file FELSUB.FOR. Thus, these two files should be compiled, and then linked to produce the executable file POISS.EXE.

When POISS.EXE is run, the program will prompt you to enter the name of the .dat data file -- which should be entered without the .dat extension -- and will open this on unit 15 and read it using the subroutine input. It will write the input data in readable form, to a file with a .prt filename extension, opened on unit 16, using the subroutine print. Also, the data is echoed to an output file with .out filename extension, opened on unit 17. During the finite element calculation, a scratch file is opened on unit 18 to store the element stiffness matrices. After performing the finite element calculation, the results are appended to the print file, and the output file, by the subroutine result. The .prt file can be printed, and the .out file is used by the post-processor FELVUE.

Program structure

The main program performs the finite element calculation by calling the following subroutines in turn: