PFATSPW
Bulk Data Entry Defines properties for Spot Weld Fatigue Analysis.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
PFATSPW | ID | SPTFAIL | ALPHA | HEXA_D | TREF | TREF_N | SF |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
ID | Each
PFATSPW card must have a unique ID. This
ID may be referenced from a FATDEF definition. No default (Integer > 0) |
|
SPTFAIL | Damage assessment
option type.
Where, is the diameter of the weld connector, α is set using the ALPHA field, and T is the thickness of the shell. |
|
ALPHA | The value of α used to determine the AUTO option on the
SPTFAIL field. Default = 3.5 (Real > 0.0) |
|
HEXA_D | Effective diameter of
the spot weld that is generated using Hexahedron
(CHEXA) elements. Default = See Comment 1 (Real ≥ 0.0) |
|
TREF | Reference thickness
for thickness effect consideration. 2 Default = 25.0 (Real > 0.0) |
|
TREF_N | Exponent for the
thickness effect consideration. 2 Default = 0.2 (Real ≥ 0.0) |
|
SF | Stress scale factor.
3 Default = 1.0 (Real > 0.0) |
Comments
- For spot weld that is generated using
Hexahedron (CHEXA) elements, grid point forces and moments are
internally calculated and resolved to the centroids of both faces of the
CHEXA weld element in contact with the sheets. The
CHEXA element is then internally considered to be equivalent
to a 1D CBAR element.The effective diameter can be calculated in two ways:
- You can directly input the effective diameter of the CHEXA-based spot weld element on the CHEXA_D field.
- If the CHEXA_D field is blank, then the effective diameter is set equal to two times the smallest distance from the face centroid to an edge in the end A. For more information, refer to Sheet Location (1 or 2) in the User Guide.
- TREF is used to define
the reference thickness for thickness effect consideration. If the thickness of
a shell (T) is greater than the specified value
(TREF), and the THCKCORR field on the
FATPARM entry is set to YES, then the
thickness effect is included by increasing the stress (
) based on:
(1) - The stress (
) can also be scaled directly using the Scale
Factor field (SF) as:
(2)