CFAILURE

I/O Options and Subcase Information Entry The CFAILURE command can be used in the I/O Options or Subcase Information sections to request failure index output for shell elements referencing PCOMP, PCOMPP or PCOMPG properties for all s or individual s, respectively.

It also supports 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

CFAILURE (format_list, NDIV, location) = option

Definitions

Argument Options Description
format <H3D, OPTI, OP2, blank>
H3D
Results are output in Hyper3D format (.h3d file).
OPTI
Results are output in OptiStruct results format (.cstr file).
OP2
Results are output in Nastran output2 format (.op2 file).
blank (Default)
Results are output in all active formats, for which the result is available.
ndiv <INTEGER>

Default = 1

 Number of divisions where composite failure indices are calculated. The maximum number of INTEGER allowed in the calculation is 5. 1 7 8
location <CENTER, CORNER, blank>
CENTER (Default)
Results are available at the element center only.
CORNER
Results are available at the element corners and at the element center.
blank
Same as CENTER.

See Comment 10.
option <YES, ALL, NO, NONE, SID, PSID>

Default = YES
YES, ALL, blank
Results are output for all elements.
NO, NONE
Results are not output.
SID
If a set ID is given, results are output only for elements listed in that set.
PSID
If a property set ID is given, results for the elements referencing properties listed in the property set are output.

Comments

  1. The following shows the planes where failure indices (FI) 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.
    NDIV
    Planes, where FI 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


    Figure 1. NDIV Planes of an Individual Ply
  2. When CFAILURE is not present, composite strength ratios are not output. CSTRESS and CSTRAIN entries cannot be used to request failure indices.
  3. 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.
  4. On the PCOMP or PCOMPG Bulk Data Entries the SOUT field must be set to YES and on the PCOMPP entry, the SOUT field on the corresponding PLY entry should be set to YES to activate failure index calculation for the corresponding ply. Also, the FT and SB fields and allowable stress (or strain) fields on the referenced materials should be defined.
  5. For plies defined on a PCOMPG Bulk Data Entry, the results are grouped by GPLYID.
  6. For optimization, the frequency of output to a given format is controlled by the I/O option OUTPUT.
  7. For shell elements, the NDIV field is supported for Static and Normal Modes Analysis only. NDIV field is supported for first and second order elements.
  8. For solid elements, NDIV is always equal to 3.
  9. Multiple instances of this card are allowed; if instances are conflicting, the last instance dominates.
  10. Corner results are available for linear static and nonlinear static (small and large displacement) analysis types only. Currently, only H3D output is supported.