PCNTX2
Bulk Data Entry Defines properties TYPE2 tied CONTACT interface for geometric nonlinear analysis.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
PCNTX2 | PID | ||||||||
IGNORE | FSPOT | LEVEL | ISRCH | IDELG |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
RUPT | IFILT | SRTID | SNTID | STTID | MAXND | MAXTD | |||
FSTR | FSTRATE | FDIST | ALPHA |
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
STFAC | VISC |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
PCONT | 34 | ||||||||
PCNTX2 | 34 |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
PID | Property identification
number of the associated PCONT. No default (Integer > 0) |
|
IGNORE | Flag to ignore slave nodes
if no master segment found for TIE contact. 6
Default as defined by CONTPRM (Integer) |
|
FSPOT | Spot weld formulation
flag.
(Integer) 20, 21,
22 - formulation with failure. Not
compatible with nodal time step
GRID(CST) on
XSTEP card. The stress is computed for
each slave node according to the "equivalent" surface around the
node. The equivalent surface is defined accordingly:
|
|
LEVEL | Hierarchy level of the
interface. No default (Integer > 0) |
|
ISRCH | Search formulation flag
for the closest master segment.
(Integer) |
|
IDELG | Node deletion flag.
|
|
RUPT | Failure model (only
available with FSPOT = 20,
21, or 22) 6
(Integer) |
|
IFILT | Filter flag. 12
(Integer) |
|
SRTID | TABLEDi
entry identification number defining stress factor vs stress rate.
8 No default (Integer ≥ 0) |
|
SNTID | TABLEDi
entry identification number defining maximum normal stress vs normal
relative displacement (ND). This function must be defined. 8 No default (Integer > 0) |
|
STTID | TABLEDi
entry identification number defining maximum tangential stress vs
tangential relative displacement (TD). This function must be defined. 8 No default (Integer > 0) |
|
MAXND | Maximum normal relative
displacement. Default = 1.0E20 (Real) |
|
MAXTD | Maximum tangential
relative displacement. Default = 1.0E20 (Real) |
|
FSTR | Stress scale factor. 8 Default = 1.00 (Real) |
|
FSTRATE | Stress rate scale factor.
8 Default = 1.00 (Real) |
|
FDIST | Distance scale factor.
8 Default = 1.00 (Real) |
|
ALPHA | Stress filter alpha
value. Default = 1.00 (Real) |
|
STFAC | Interface stiffness scale
factor. (Only used with FSPOT =
25). Default = 1.00 (Real) |
|
VISC | (Optional) Critical
damping coefficient on interface stiffness (Only used with
FSPOT = 25). Default = 0.05 (Real) |
Comments
- The property identification number must be that of an existing PCONT Bulk Data Entry. Only one PCNTX2 property extension can be associated with a particular PCONT.
- PCNTX2 is only applied in geometric nonlinear analysis subcases which are defined by ANALYSIS = EXPDYN. It is ignored for all other subcases.
- PCNTX2 is only valid for tied contact specified using the TIE Bulk Data Entry. The PID field on the TIE entry can be used to reference the PCNTX2 entry.
- Interface TYPE2 is a kinematic condition, no other kinematic condition should be set on any nodes of the slave surface.
- The default value for SRCHDIS is the average of the mater segments.
- If IGNORE = 1 or 2, the slave nodes without a master
segment found during the searching are deleted from the interface;
If IGNORE = 1 and SRCHDIS is blank, then the default value of the distance for searching closest master segment is the average size of the master segments;
If IGNORE = 2 and SRCHDIS is blank, then the distance for searching closest master segment is computed as follows for each slave node:
d1 = 0.6 * (Ts + Tm)
d2 = 0.05 * Tmd
SRCHDIS = max(d1 , d2)
Where,- Ts
- Thickness of the element connected to the slave node, for solids Ts = 0.0
- Tm
- Thickness of master segment, for solids Tm = Element volume / Segment area
- Tmd
- Master segment diagonal
- Master nodes of an interface TYPE2 may be slave nodes of another interface TYPE2 if the hierarchy level of the first interface is lower than the hierarchy level of the second interface. Hierarchy levels are only available with FSPOT=2.
- For failure (FSPOT =
20, 21, or 22), it could
model glue connection. In this case, the force in slave node will be scaled by
reduced force coefficient
(
), which is computed as:
(1) The reduced force is compared to the maximum value:
If , then = 1, which means the force will not be reduced.
If , then , which means the force will then be reduced.
Here the maximum value will be defined by you with:
Where,- Maximum normal stress value defined by SNTID
- Normal stress
- Maximum tangential stress value defined by STTID
- Tangential stress
- FSTR
- Input constant stress factor
- SRTID
- Input variable coefficient
- SNTID and STTID
- Input stress-displacement tables
Once the rupture criterion (defined by Rupt) is reached, the contact will be deleted.
- If RUPT =
1, the failure criterion is:
(2) - If FSPOT = 30, slave mass/inertia/stiffness distribution to the master node is based on the Kirschoff model: bi-cubic form functions are used instead of linear (standard formulation). It allows a softer contact behavior since the element shape curvature is taken into account in the force/moment transmission.
- If IDELG = 1, then when a 4-node shell, a 3-node shell or a solid element is deleted, it is also removed from the master side of the interface (kinematic condition is suppressed on relative slave nodes).
- If IFILT is set to
1, the normal and tangential stresses are filtered with an
alpha filter, as:
(3) (4) - FSPOT = 25 (penalty formulation) will keep the penalty formulation during the whole run. The slave node (of this contact) could also be the slave node of another kinematic option, like rigid body. The penalty stiffness is constant, calculated as the mean nodal stiffness of master and slave side. The stiffness factor, STFAC, may be used to modify it, if needed. The penalty stiffness will be multiplied by STFAC. A critical viscous damping coefficient (VISC) allows damping to be applied to the interface stiffness.