Element Forces
OVERVIEW
REPTILE can be used to extract element forces across many load cases and output files in a single step. REPTILE currently supports the following element types (program mode in parentheses).
- CBAR, CBEAM, CROD (--bar_forces)
- CBUSH (--bush_forces)
- CFAST (--cfast_forces)
- CGAP (--gap_forces)
- CQUAD, CTRIA (--shell_forces)
Input File Format
For REPTILE to extract element forces, we must tell it which elements we want. This is done with an Input File, which is just a text file with a list of element IDs in it. The ID list can be all on one line, or spread over multiple lines.
REPTILE understands "Patran-Style" list syntax, which makes writing sequential lists more compact (e.g. "15:24" means all IDs from 15 to 24, "30:120:10" means IDs from 30 to 120 counting by 10's).
Here is an example Input File:
REPTILE understands "Patran-Style" list syntax, which makes writing sequential lists more compact (e.g. "15:24" means all IDs from 15 to 24, "30:120:10" means IDs from 30 to 120 counting by 10's).
Here is an example Input File:
5 21 103 65 1770 81
1401:1406 1421 1423 1607
2141 2364 2891:3091:5 3282
The Input File format is the same for all of REPTILE's Element Force modes.
EXAMPLE Command Lines
REPTILE can be invoked from a batch script (recommended) or from a command prompt (not recommended), but in either case, the command lines look the same. See Getting Started for more information.
Every element force mode requires 3 command line arguments:
So a minimal element force command line might look like this:
Every element force mode requires 3 command line arguments:
- An Input File (as described above)
- An Output Filename (output is in CSV format by default)
- The XDB File(s) to process (wildcards are allowed)
So a minimal element force command line might look like this:
reptile --bar_forces -i Input_File.e -o Output_File.csv file1.xdb
Of course, wildcards are allowed for the XDB Files, so if you have a lot of XDB Files, you might do this:
reptile --bush_forces -i Input_File.e -o Output_File.csv file*.xdb
Now lets say you want to output to a SDIO and perform Load Combinations. First, we need to add a "-SDIO" option which tells REPTILE to generate a SDIO file after it creates the SDIO file (See SDIO Output for more info). Note: It doesn't matter where in the command line you put a option like this. Second, instead of giving REPTILE one or more XDB Files, we use the "-COMB" option and give it the name of the file that defines the load combinations (this file will point to the appropriate XDB Files) (See Load Combinations for more info).
So the final command line will look like this:
So the final command line will look like this:
reptile --shell_forces -i Input_file.e -o Output_File.csv -SDIO -COMB file.comb
Other Options
Some of REPTILE's Element Force modes have other options, so lets go through them.
--bush_forces
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"-SCI" option will write the BUSH element forces in scientific notation
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--shell_forces
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"-IJK" option outputs SHELL element forces in the element IJK system
"-MATL" option outputs SHELL element forces in the element material system "-NOMQ" option supresses the output of moments and transverse shears "-INV" option calculates invariants (max/min principal, max shear, von-mises) |