CNTITF

Bulk Data Entry Defines parameters for contact (S2S and N2S) interference.

This entry is supported with nonlinear static and nonlinear transient analysis types for both small and large displacement analysis. The CNTITF Bulk Data Entry should be referenced by a CNTITF Subcase Information Entry to be applied in a particular subcase.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CNTITF ID METHOD H1
The following continuation line (beginning with the CNTINT flag) is used to define another set of interference parameters, which locally overrides the set of parameters above, and applies locally on a specific contact interface (CTID). It can be repeated as required.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CNTINT CTID METHOD H1

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
CNTITF 98 INST
CNTINT 51 INCR 0.01
  CNTINT 52 LEAVE            
CNTINT 53 222 -0.01

Definition

Field Contents SI Unit Example
ID Each CNTITF Bulk Data Entry should have a unique ID.

No default (Integer > 0)

  
METHOD Flag indicating how contact interference is applied.
INCR (Default)
Initial contact penetration is resolved over one subcase (incrementally).
LEAVE
Initial contact penetration is kept in the current subcase.
The penetrated area is regarded as zero penetration.
INST
Initial contact penetration is resolved in one incremental step (instantly).
Integer
Table ID as per which penetration is resolved.
  
H1 The amount of allowable penetration, which will not be resolved in the subcase and its continued subcases. Contact with penetration smaller than this value is considered as open.
Blank (Default)
0.0
Real
The allowable penetration.
Note: If the METHOD field is set to INST or LEAVE, the H1 field should be blank. A negative value of H1 gives an opening with magnitude of -H1 at the end of subcase. 3 4
  
CNTINT Defines the start of a continuation line used to specify another set of interference parameters, which overrides the set of parameters defined above, for a specific contact interface (CTID). It can be repeated as required.  
CTID Contact interface identification number.

No default (Integer > 0)

  

Comments

  1. The CNTITF Bulk Data Entry is selected by the CNTITF Subcase Information Entry.
  2. TABLES1 and TABLEG can be referenced in METHOD field. In the table, time and factor are defined in X- and Y- column, respectively. The factors are multiplied on the H1 amount to indicate the restored penetration amount at the specified time. The y-value of the last point (ylast) specifies the ratio of the allowable penetration over the H1 value in the following subcases. When yi*H1 is negative, it is equivalent to having an opening with magnitude of - yi*H1.
  3. Negative values are allowed in the H1 field, whose magnitude is the gap distance after interference. This gap distance will be kept in the following subcases. It is equivalent to an additional GPAD in contact. Further, when a curve is referenced by METHOD field in CNTITF, negative Y-value is allowed.
  4. When GPAD exists in contact definition, and table defined curve is used for interference, the initial penetration will include the amount of GPAD. In this case, the coefficients taken from the table will be multiplied on the initial penetration (include the GPAD effect) to decide the amount of penetration to be kept at each time step.
  5. When a CNTITF card is not defined in a deck file, initial contact penetration of all N2S and S2S contact will be resolved in the root subcase, which is equivalent to METHOD = INCR and H1 =0.0.