CSTRAIN
I/O Options and Subcase Information Entry Used in the I/O Options or Subcase Information sections to request ply strain output for shell elements referencing PCOMP, PCOMPP or PCOMPG properties for all subcases or individual subcases, respectively.
It is also supported for solid elements referencing PCOMPLS or PSOLID with MAT9 for linear static, nonlinear static (both small and large displacement) and nonlinear transient (both small and large displacement) analysis for H3D format.
Format
CSTRAIN (format_list,type,random,extras_list,NDIV, location) = option
Definitions
Argument | Options | Description |
---|---|---|
format | <HM, H3D, OPTI, PUNCH, OP2, PLOT, HDF5 blank> |
|
type | <ALL, PRINC, TENSOR,
DIRECT> Default = ALL (in DIRECT format) |
|
random | <PSDF,
RMS> No default |
|
extras | <MECH,
THER> No default |
|
ndiv | <INTEGER> Default = 3 |
Number of divisions where composite strains are calculated. The maximum number of ndiv allowed in the calculation is 5. 10 - 14 |
location | <CENTER, CORNER, blank> |
See Comment 16. |
option | <YES,
ALL, blank, NO,
NONE, SID, PSID> Default = YES, ALL, blank |
|
Comments
- When the CSTRAIN command is not present, ply strain results are not output.
- The STRAIN I/O Option controls the output of strain results for the homogenized composite material.
- Multiple formats are allowed on the same entry; these should be comma separated. If a format is not specified, this output control applies to all formats defined by the OUTPUT command, for which the result is available.
- Multiple instances of this card are allowed; if instances are conflicting, the last instance dominates.
- The SOUT field on the PCOMP or PCOMPG Bulk Data Entry must be set to YES to activate strain results calculation for the corresponding ply. For PCOMPP entries, the SOUT field on the corresponding PLY entries should be set to YES.
- For plies defined on a PCOMPG Bulk Data Entry, the results are grouped by GPLYID.
- For optimization, the frequency of output to a given format is controlled by the I/O option OUTPUT.
- The mechanical and thermal contributions to strain may be requested in addition to the total strain.
- format=OUTPUT2 can also be used to request results to be output in the Nastran output2 format (.op2 file).
- For shell elements, the following
shows the planes where Composite Strains are calculated for different
ndiv values. BOT, MID
and TOP represents the bottom, middle and top planes of an
individual ply. Division numbers represents the relative distance of a
plane/division from the bottom of a ply. For solid elements,
ndiv is always 3.
- NDIV
- Planes, where composite strains are calculated
- 1
- MID
- 2
- BOT, TOP
- 3
- BOT, MID, TOP
- 4
- BOT, 0.33, 0.67, TOP
- 5
- BOT, 0.25, MID, 0.75, TOP
- If different ndiv values are specified in CSTRESS, CSTRAIN, and CFAILURE, the largest value is used in the composite stress, strain, and failure indices calculations.
- When CFAILURE is not present, composite strength ratios are not output. CSTRESS and CSTRAIN entries cannot be used to request failure indices.
- For shell elements, the NDIV field is supported for linear static, nonlinear static (small and large displacement), normal modes, direct frequency response, modal frequency response, direct transient, modal transient and nonlinear transient (small and large displacement) analysis types only. The NDIV field is supported for first and second order elements.
- For solid elements, NDIV is always equal to 3, regardless of the user input.
- The HDF5 output is printed to a
.h5 binary results file. For details of the supported
analysis types and elements when the .h5 output format is
requested, refer to the .h5 file.
For details about the old HDF5 format (.hdf5), refer to PARAM, HDF5 and .hdf5 file.
- Corner results are available for linear static and nonlinear static (small and large displacement) analysis types only. Currently, only H3D output is supported.