Output radiation view factors and facet areas: FRAD

The program shows how to retrieve the view factors and the facet areas from the results file. The results file created from the benchmark problem detailed in Axisymmetric elemental cavity radiation view factor calculations is used to verify that the output records have been read and output correctly. This program will assume that the results file has the default file extension, .fil, which corresponds to Fortran unit 8.

Before proceeding, review the general discussion on programming concepts and Abaqus Fortran interfaces in About user postprocessing of Abaqus results files and the detailed discussion of postprocessing given in File Output Format.

When running the program FRAD (this program is named frad.f on the Abaqus release media), the user will be prompted for the file name that initializes FNAME. Other variables, such as LOUTF, NRU, LRUNIT(1,NRU), and LRUNIT(2,NRU), are initialized inside the program. INITPF and DBNRU are then called to complete the necessary initializations and file connections. By default, the results file is processed for all steps and increments in the results file. The user can restrict the output by setting LSTEPA and LINCA to the required step and increment and uncommenting the simple IF - END IF block. Data processing starts with a DO-loop over all the records to be read, one-by-one, by means of a call to DBFILE. Each record is identified by its record key, which is stored in the second entry of the record. When records 1922 and 2000 are processed by FRAD, the heading and the current step and increment numbers are written out so as to provide a way to recognize the beginning of data in each analysis. Record types 1605, 1606, 1607, and 1609 are then read; and the desired output is written to the output file vfout.

Before it can be executed, the Fortran program must be compiled and linked. Both operations, as well as the inclusion of the aba_param.inc file, are performed by a single execution of the abaqus make utility:

abaqus make job=frad

This procedure may have to be repeated until all Fortran errors are corrected. After successful compilation, the program's object code is linked automatically with the Abaqus object codes stored in the shared program library and the interface library to build the executable program. Refer to System customization parameters for information about the compile and link commands for a particular computer.

Before the program is executed, a results file must have been created with the desired output being written to that file. In this example the results file xrvda4n1.fil created by running the input file xrvda4n1.inp discussed in Axisymmetric elemental cavity radiation view factor calculations is used. When the program is executed using the command abaqus frad, the prompt

Enter the name of the input file (w/o .fil):

will appear. Enter xrvda4n1 to define FNAME. The program processes the data and produces a file named vfout, which contains the required information.