/RLINK
Block Format Keyword Defines a rigid link. The rigid link imposes the same velocity on all the secondary nodes in one or more directions.
Format
(1)  (2)  (3)  (4)  (5)  (6)  (7)  (8)  (9)  (10) 

/RLINK/rlink_ID  
rlink_title  
Trarot  Skew_ID frame_ID  grnod_ID  Ipol 
Definition
Field  Contents  SI Unit Example 

rlink_ID  Rigid link
integer. (Integer, maximum 10 digits) 

rlink_title  Rigid link
title. (Character, maximum 100 characters) 

Trarot  Codes for translation and rotation.
(6 Booleans) 

Skew_ID / frame_ID  Frame identifier for
Ipol=0 or frame identifier
for Ipol=1. 3 If Skew_ID ≠ 0: the code refers to this local skew (or frame) identifier. If Skew_ID = 0: the code refers to the global coordinate system. (Integer) 

grnod_ID  Secondary nodes group
identifier. (Integer) 

Ipol  Polar rigid link flag.
3
(Integer) 
Codes for Translation and Rotation: input format for the first field (1) Trarot
If Ipol = 0
(1)1  (1)2  (1)3  (1)4 first boolean  (1)5 second boolean  (1)6 third boolean  (1)7  (1)8 fourth boolean  (1)9 fifth boolean  (1)10 sixth boolean 

T_{X}  T_{Y}  T_{Z}  ${\omega}_{X}$  ${\omega}_{Y}$  ${\omega}_{Z}$ 
If Ipol = 1
(1)1  (1)2  (1)3  (1)4 first boolean  (1)5 second boolean  (1)6 third boolean  (1)7  (1)8 fourth boolean  (1)9 fifth boolean  (1)10 sixth boolean 

T_{rad}  T_{axial}  T_{tang}  ${\omega}_{rad}$  ${\omega}_{\mathrm{axial}}$  ${\omega}_{\mathrm{tang}}$ 
Definition
Field  Contents  SI Unit Example 

T_{X}  Code for translation along
Xaxis.
(Boolean) 

T_{Y}  Code for translation along
Yaxis.
(Boolean) 

T_{Z}  Code for translation along
Zaxis.
(Boolean) 

${\omega}_{X}$  Code for rotation around
Xaxis.
(Boolean) 

${\omega}_{Y}$  Code for rotation around
Yaxis.
(Boolean) 

${\omega}_{Z}$  Code for rotation around
Zaxis.
(Boolean) 

T_{rad}  Code for translation in
radial direction.
(Boolean) 

T_{axial}  Code for translation in
axial direction.
(Boolean) 

T_{tang}  Code for translation in
tangential direction.
(Boolean) 

${\omega}_{rad}$  Code for rotation in
radial direction
(Boolean) 

${\omega}_{\mathrm{axial}}$  Code for rotation in axial
direction.
(Boolean) 

${\omega}_{\mathrm{tang}}$  Code for rotation in
tangential direction.
(Boolean) 
Comments
 The velocity is computed using momentum
conservation equations. However, no global momentum equilibrium is respected.
 For translational DOF:$${T}_{X}=\frac{{\displaystyle \sum _{j=1}^{N}{M}_{j}{T}_{X}^{j}}}{{\displaystyle \sum _{j=1}^{N}{M}_{j}}}$$
 For rotational DOF:$${\omega}_{X}=\frac{{\displaystyle \sum _{j=1}^{N}{I}_{j}{\omega}_{X}^{j}}}{{\displaystyle \sum _{j=1}^{N}{I}_{j}}}$$
 For translational DOF:
 Input format details for Trarot are shown above. The six individual boolean codes (one per direction) must be right justified in the 10 character fields used by the Trarot variables.
 If Ipol
=1, polar coordinate system is used;
frame_ID definition is compulsory. In this case, not only
direction of the axis is set, but also the position of the center of the polar
coordinate system.
 The first boolean code corresponds to the radial direction effect
 The second boolean code corresponds to the axial effect
 The third boolean corresponds to the tangential effect
 Axial direction is defined by the X direction of the frame
 Radial direction is orthogonal to axial direction and is passing through concerned node
 Tangential direction is orthogonal to axial and radial directions