MATFATT

Bulk Data Entry Defined temperature-dependent material properties for fatigue analysis.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
MATFATT MID TEMPUNIT
Continuation lines that define Temperature versus Haigh Diagrams. This block of continuation lines can be repeated to define one Haigh Diagram at each temperature (Ti).
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
TEMP Ti
SNTBL REFTYPE LogSE Nc1 Nc FINDLEY STSTYPE
REFVAL A1 B1 A2 B2 A3 B3
A4 B4 A5 B5 etc.

Definitions

Field Contents SI Unit Example
MID Material identification number that matches the identification number on a MAT1 Bulk Data Entry and the corresponding MATFAT entry.

No default (Integer > 0)

TEMPUNIT Temperature unit.

Default = C (C, F)

TEMP Flag indicating that the temperature value follows.
Ti Temperature at which the corresponding Haigh diagram is defined. A single Haigh diagram can be defined at each temperature (Ti).

No Default (Real)

SNTBL Flag indicating that X-Y data for a Haigh Diagram follows.
REFTYPE Reference type identifying the type of curve definition.
LIFE

Ai, Bi data below represents a single Haigh diagram. The life value for the Haigh diagram curve is identified via the REFVAL field.

No default (LIFE)

LogSE Standard Error of log(Stress).

Default = 0.0 (Real > 0.0)

Nc1 Fatigue transition point. After this point, fatigue strength is offset by the surface correction factor. Before this point, fatigue strength is proportionally reduced.

Default = NC (Real > Nc_stat)

Nc Endurance limit. Number of cycles at which damage can be considered zero.

Default = 1.0E+8 (Real > 1.0E+5)

FINDLEY Constant k in the Findley model.

Default = 0.3 (Real > 0.0)

STSTYPE Stress type.
R (Default)
Range.
A
Amplitude.
MAX
Maximum stress.
REFVAL1 Reference value of Life for which the Haigh Diagram is defined.

No default (Real)

Ai Depending on STSTYPE, Ai values can be one of stress amplitude, stress range, or max stress.
Bi Depending on REFTYPE, Bi values can be life (REFTYPE=MEAN or RRATIO) or mean stress (REFTYPE=LIFE).

No default

Comments

  1. The MID field of the MATFATT entry should match with a corresponding MATFAT entry (which is used to define basic information such as stress units and length) and a MAT1 entry.
  2. Only a single Haigh diagram per temperature is currently supported. Therefore, only safety factor analysis is currently supported with MATFATT.
  3. Static failure is currently not supported with the MATFATT Bulk Data Entry.