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!CONTACT

Definition of contact conditions

Parameter

GRPID       = Boundary conditions group ID
INTERACTION = SSLID (Infinitesimal slip contact, Default) / FSLID (Finite slip contact) / TIED (Tied)
NTOL        = Contact normal direction convergence threshold (Default: 1.e-5)
TTOL        = Contact tangential direction convergence threshold (Default: 1.e-3)
NPENALTY    = Contact normal direction Penalty (Default: stiffness matrix 1.e3)
TPENALTY    = Contact tangential direction Penalty (Default: 1.e3)
DAMP_ALPHA  = Contact damping coefficient (dimensionless, Default: 0.0 = no damping)
DAMP_GACT   = Activation distance of contact damping (length, Default: 0.0 = no damping)
CONTACTPARAM = Contact scan parameter set name（specified by `!CONTACT_PARAM, NAME`）
SMOOTHING   = NONE (No smoothing, Default) / NAGATA (Smoothing of the master surface by Nagata patches)

2nd line or later

Using INTERACTION = SSLID, FSLID

(2nd line) PAIR_NAME, fcoef, factor
Parameter Name Attributions Contents
PAIR_NAME C Contact pair name (Defined in !CONTACT PAIR)
fcoef R Friction coefficient (Default: 0.0)
factor R Friction penalty stiffness

Using INTERACTION = TIED

(2nd line) PAIR_NAME
Parameter Name Attributions Contents
PAIR_NAME C Contact pair name (Defined in !CONTACT PAIR)

Example of Use

!CONTACT_ALGO, TYPE=SLAGRANGE
!CONTACT, GRPID=1, INTERACTION=FSLID
CP1, 0.1, 1.0e+5

With contact damping

!CONTACT_ALGO, TYPE=SLAGRANGE
!CONTACT, GRPID=1, INTERACTION=FSLID, DAMP_ALPHA=1.0e-2, DAMP_GACT=2.0e-2
CP1, 0.0, 5.0e+2

Note

  • if CONTACTPARAM is specified, the destination !CONTACT_PARAM must be defined prior to the !CONTACT card. If this parameter is omitted, the default contact scan parameter set is used.
  • Contact damping takes effect only when both DAMP_ALPHA and DAMP_GACT are positive. Specifying only one of them has no effect.
  • See Functions reference: Contact and Embedding for an overview of contact damping and how to choose the damping coefficient and the activation distance.
  • SMOOTHING=NAGATA is used for contact whose master surface consists of faces of first-order triangular or quadrilateral elements.