# /FRIC_ORIENT

Block Format Keyword Define specific directions for orthotropic contact friction for the main surface for contact interfaces TYPE7, TYPE19, TYPE24, and TYPE25.

These orientations are used when an orthotropic friction model is defined in /FRICTION Idir=1. Only shell elements are supported.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/FRIC_ORIENT/fric_ID
friction_orientation_title
Repeat these two lines to define different friction orientation values for specific parts or groups of parts
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
/FRIC_ORIENT/fricorient_ID
friction_orientation_title
grpart_ID part_ID
VX VY VZ Skew_ID $\varphi$ Iorth

## Definition

Field Contents SI Unit Example
fric_ID Friction identifier.

(Integer, maximum 10 digits)

friction_orientation_title Friction model title.

(Character, maximum 100 characters)

grpart_ID Part group identifier /GRPART.

(Integer)

part_ID Part identifier.

Ignored if, grpart_ID is defined.

(Integer)

VX X component for reference vector.

Default = 1.0 (Real)

VY Y component for reference vector.

Default = 1.0 (Real)

VZ Z component for reference vector.

Default = 1.0 (Real)

Skew_ID Skew identifier for reference vector. 2

If the local skew is defined, its X-axis replaces the global vector, $V$ .

VX, VY and VZ coordinates are ignored.

Default = 0 (Integer)

$\varphi$ Angle. 2

(Real)

$\left[\mathrm{deg}\right]$
Iorth Orthotopic system formulation flag for reference vector.
= 0 (Default)
The first axis of orthotropy is maintained at constant angle with respect to the X-axis of an orthonormal co-rotational.
= 1
The first orthotropy direction is constant with respect to a non-orthonormal system of deformed element.

(Integer)

## Example

#RADIOSS STARTER
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FRICTION/999
test no 1
#    Ifric    Ifiltr               Xfreq     Iform
0         0                   0         2
# default friction for rest parts which not specifically defined below
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .2                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#friction between part group ID 111 and ID 222
#GRpartID1 GRpartID2  PartID_1  PartID_2                Idir
111       222         0         0	               0
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .1                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#friction between part ID 1 and ID 3
#GRpartID1 GRpartID2  PartID_1  PartID_2                Idir
0         0         1         3	               0
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .2                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#friction between part ID 1 and ID 4; orthotropic direction considered
#GRpartID1 GRpartID2  PartID_1  PartID_2                Idir
0         0         1         4                   1
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .4                   0
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .2                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#friction between part ID 1 and ID 5
#GRpartID1 GRpartID2  PartID_1  PartID_2                Idir
0         0         1         5	               0
#                 C1                  C2                  C3                  C4                  C5
0                   0                   0                   0                   0
#                 C6                Fric                VisF
0                  .3                   0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/INTER/TYPE7/2
New INTER 2
#  Slav_id   Mast_id      Istf      Ithe      Igap                Ibag      Idel     Icurv      Iadm
9        10         4         0         2                   0         1         0         0
#          Fscalegap             Gap_max             Fpenmax
0                   0                 0.8
#              Stmin               Stmax          %mesh_size               dtmin  Irem_gap   Irem_i2
1                   0                   0                   0         0         0
#              Stfac                Fric              Gapmin              Tstart               Tstop
0                 .35                 2.1                   0                   0
#      IBC                        Inacti                VisS                VisF              Bumult
000                             6                   0                   0                   0
#    Ifric    Ifiltr               Xfreq     Iform   sens_ID   fct_IDf             AscaleF   fric_ID
0         0                   0         2         0         0                   0         0
/GRNOD/PART/9
INTER_group_9_of_SURF
4         5
/SURF/PART/10
INTER_group_10_of_PART
1
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FRIC_ORIENT/1
define orientation of part ID 1
# GRpartID    PartID
1
#                 Vx                  Vy                  Vz   skew_ID                 Phi     Iorth
1                   0                   1                            45
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
Table 1. Friction used by model based on input example
Parts Idir Friction Coefficient
All parts not listed - 0.2
/GRPART/111 - /GRPART/222 0: Isotropic 0.1
part_ID1 - part_ID3 0: Isotropic 0.2
part_ID1 - part_ID4 1: Orthotropic Dir1 = 0.4 Dir2 = 0.2
part_ID1 - part_ID5 0: Isotropic 0.3

In this example, the orthotropic direction for friction between parts 1 and 4 is defined by the vector and angle in /FRIC_ORIENT/1.

• Skew_ID =0: Orthotropic direction defined with global vector $V$ (components defined in Line 4) and angle $\varphi$ (angle in degree).
• Skew_ID ≠0: Orthotropic direction defined with skew (X-axis in skew replaces the global vector $V$ ) and angle $\varphi$ (angle in degree).
For both ways (with vector $V$ or with skew), the projection of vector $V$ (or x-axis of skew) on shell element plane becomes the vector $V\text{'}$ . Then the orthotropic direction (direction 1) is vector $V\text{'}$ turned ${\varphi }_{i}$ degrees where the positive direction is based on the shell normal $n$ .