flexprep
Creates and translates flexbody H3D files.
Syntax
flexprep <source>.<bdf|nas|dat|fem|blk> <target>.h3d <mode_type_option> <+interface_node_list> [upper_freq [HZ]] [-<units>] [-<stress>] -ospath:<DEFAULT|directory>
flexprep <source>.pch <target>.h3d [-<units>]
flexprep <source>.mnf <target>.h3d [invar_option] [-<NO_UNIT_CONV>]
flexprep <source>.h3d <target>.h3d [-<mirror option>]
flexprep <source>.h3d <target>.mtx [invar_option] [+node_list] [+mode_list] [-<units>] [-<mirror option>]
flexprep <source>.h3d <target>.mnf flexprep <source>.h3d <target>.fdf [+mode_list] [-<units>]
flexprep <source>.h3d <target>.<fes|asc>
Application
Translators
Description
Creates flexbody H3D files using OptiStruct.
Creates flexbody H3D file from ADAMS MNF and Nastran PCH.
Translates flexbody H3D file to ADAMS MTX, Altair H3D (mirrored), ADAMS MNF, DADS FDF, and nCode FES.
Inputs
- Nastran Bulk Data File to H3D
-
- <mode_type_option>
- Specifies the method of computing mode types. Available options are:
- ‘CB’ (Craig-Bampton)
- ‘CC’ (CRAIG_CHANG)
- ‘FR’ (FREQUENCY-RESPONSE)
- ‘FF’ (FREE-FREE).
- ‘CBX’ (Craig-Bampton) is used when all the OptiStruct data has been generated in the same directory and needs to be processed and put together into an H3D file.
- <+interface_node_list>
- The set of interface nodes. Use the ‘+’ symbol to combine different interface nodes or use ‘:’ to denote a range.
- [upper_freq [HZ]]
- When Hz is specified, denotes the upper frequency. Otherwise, it specifies the number of eigen modes.
- [-<units>]
- Specifies the units of the original Nastran model. See the Unit Options below.
- [-<stress>]
- If specified, stress information is generated by OptiStruct.
- [-<strain>]
- If specified, strain information is generated by OptiStruct.
- -ospath:<DEFAULT|directory>
- Specifies the location of OptiStruct. If DEFAULT is specified, the current installation of OptiStruct will be used.
- Nastran Punch File to H3D
-
- [-<units>]
- Specifies the units of the original Nastran punch file. See Unit Options below.
- ADAMS MNF to H3D
-
- [invar_option]
- List of invariant options that should be moved/generated from the MNF file to the H3D file. This argument is specified with a total of nine true and false.
- [-<NO_UNIT_CONV>]
- If specified, keeps the MNF model’s units. Do not convert to H3D units.
- H3D to H3D
-
- [-<mirror_option>]
- Specifies the plane about which to mirror the H3D model.
Available options are:
- MIRROR_XY
- MIRROR_XZ
- MIRROR_YZ
- H3D to ADAMS MTX
-
- [invar_option]
- List of invariant options that should be moved/generated from the H3D file to the MTX file. This argument is specified with a total of nine true and false.
- [+node_list]
- The set of interface nodes. Use the ‘+’ symbol to combine different interface nodes or use ‘:’ to denote a range.
- [+mode_list]
- The list of modes to include in the MTX file. Use the ‘+’ symbol to combine different interface nodes or use ‘:’ to denote a range.
- [-<units>]
- Specifies the units of the original H3D model. See Unit Options below.
- [-<mirror_option>]
- Specifies the plane about which to mirror the H3D model about.
Available options are:
- MIRROR_XY
- MIRROR_XZ
- MIRROR_YZ
- H3D to DADS fdf
-
- [-<units>]
- Specifies the units of the original H3D model. See Unit Options below.
Unit Options
- Mass unit
- GRAM, KILOGRAM, MEGAGRAM, POUND_MASS, SLUG, OUNCE_MASS, KPOUND_MASS
- Length unit
- INCH, FOOT, MILE, MILLIMETER, CENTIMETER, METER, KILOMETER
- Force unit
- OUNCE_FORCE, POUND_FORCE, KPOUND_FORCE, DYNE, NEWTON, KILOGRAM_FORCE, KNEWTON
- Time unit
- MILLISECOND, SECOND, MINUTE, HOUR
Example
flexprep xxx.pch yyy_flex.h3d -METER -KILOGRAM_FORCE
flexprep xxx.mnf yyy_flex.h3d
flexprep xxx_flex.h3d yyy.mtx TTTTTTTTF +1+1001 +7:9+11:15 -METER
Unit of the resulting mtx file can be specified (as METER in this example) in the options list. The default is KILOGRAM, MILLIMETER, NEWTON, and SECOND. In general, modes 1-6 are the rigid body modes so the valid mode number should start from 7.
flexprep xxx_flex.h3d yyy.mtx TTTTTTTTF +ALL +ALL -METER -MIRROR_XZ
flexprep xxx_flex.h3d yyy_flex.h3d -MIRROR_XZ
If interface nodes block exists in the .h3d file (e.g. read from .mnf file interface node block or if the .h3d is from flexprep/OptiStruct analysis), then interface nodes will be selected, plus additional non-interface nodes (non-force bearing node, or sensory nodes).
flexprep xxx_flex.h3d yyy.mtx TTTTTTTTF +I+6:8+10 +ALL -METER
Compute Craig-Bampton modes with nodes 1 and 1001 as the interface nodes and 10 eigen modes.
flexprep xxx.blk yyy_flex.h3d CB +1+1001 10 -STRESS
flexprep xxx.blk yyy_flex.h3d CB +1+1001 1000.0 HZ
flexprep xxx.blk yyy_flex.h3d CBX +1+1001 1000.0 HZ
Same as above CB, but only write out fem files (for manually invoking OptiStruct analysis). No .h3d file will be produced.
flexprep xxx.blk dummy.h3d CB +1+1001 1000.0 HZ -FEMONLY -PURGE
flexprep xxx.blk yyy_flex.h3d CB +1+1001 1000.0 HZ -EIG:zzz_eig.fem
flexprep xxx.blk yyy_flex.h3d FF +1+1001 1000.0 HZ -STRESS
Compute 10 free-free eigen modes and frequency-response attachment modes with nodes 1 and 1001 as the interface nodes.
flexprep xxx.blk yyy_flex.h3d FR +1+1001 10
Comments
flexprep checks the file extensions on the specified source and target files to determine the appropriate translation.