7.2. Command Changes

The TB command now includes these FRIC — Coefficient of Friction Specifications.

NTEMP:

The humber of temperatures for which data will be provided. Default = 1. No maximum limit.

NTEMP is not used in the following situations:

Isotropic or orthotropic friction defined in terms of field data (TBFIELD command)
User-defined friction (TBOPT = USER)

NPTS:

Number of data points to be specified for user-defined friction (TBOPT = USER).

Not used for TBOPT = ISO or TBOPT = ORTHO.

TBOPT:

Friction options:

ISO --: Isotropic friction (one coefficient of friction, μ) (default). This option is valid for all 2D and 3D contact elements.
ORTHO --: Orthotropic friction (two coefficients of friction, μ1 and μ2). This option is valid for the following 3D contact elements: CONTA174, CONTA175, and CONTA177.
FORTHO --: Orthotropic friction (two coefficients of friction, μ1 and μ2) with a friction coordinate system fixed in space. This option is valid for the following 3D contact elements: CONTA174, CONTA175, and CONTA177.
EORTHO --: Equivalent orthotropic friction (two coefficients of friction, μ1 and μ2). This option differs from TBOPT = ORTHO only in the way the friction coefficients are interpolated when they are dependent upon the following field variables: sliding distance and/or sliding velocity. In this case, the total magnitude of the field variable is used to do the interpolation.
ATAN --: Isotropic friction (one coefficient of friction, MU) wherein frictional stress is a function of sliding velocity.
USER --: User defined friction. This option is valid for all 2D and 3D contact elements.