"Optional title"
coid
entype${}_1$, enid${}_1$, entype${}_2$, enid${}_2$, bc${}_{tr}$, bc${}_{rot}$, csysid${}_1$, csysid${}_2$
$rx-$, $rx+$, $ry-$, $ry+$, $rz-$, $rz+$, $gap$, $\xi$, $pfac$
cid${}_{Tx}$, cid${}_{Ty}$, cid${}_{Tz}$, $T^f_x$, $T^f_y$, $T^f_z$, cid${}_{Fx}$, cid${}_{Fy}$, cid${}_{Fz}$
Parameter definition
Variable | Description |
---|---|
coid | Joint ID |
entype${}_1$ | Entity type 1 |
enid${}_1$ | Entity identification number 1 |
entype${}_2$ | Entity type 2 |
enid${}_2$ | Entity identification number 2 |
bc${}_{tr}$ | Constrained translational degrees of freedom |
bc${}_{rot}$ | Constrained rotational degrees of freedom |
csysid${}_1$ | ID of coordinate system defining initial location of joint and orientation of Entity 1 |
csysid${}_2$ | ID of coordinate system defining initial orientation of Entity 2 |
$rx-$ | Maximum free rotation angle around x-axis in negative direction (deg) |
$rx+$ | Maximum free rotation angle around x-axis in positive direction |
$ry-$ | Maximum free rotation angle around y-axis in negative direction |
$ry+$ | Maximum free rotation angle around y-axis in positive direction |
$rz-$ | Maximum free rotation angle around z-axis in negative direction |
$rz+$ | Maximum free rotation angle around z-axis in positive direction |
$gap$ | Joint gap in all directions (clearance) |
$\xi$ | Fraction of critical damping of joint forces |
$pfac$ | Optional user defined joint stiffness |
cid${}_{Tx}$ | ID of CURVE describing torque as function of rotation around local x-axis (deg) |
cid${}_{Ty}$ | ID of CURVE describing torque as function of rotation around local y-axis |
cid${}_{Tz}$ | ID of CURVE describing torque as function of rotation around local z-axis |
$T^f_x$ | Friction torque when rotating around local x-axis |
$T^f_y$ | Friction torque when rotating around local y-axis |
$T^f_z$ | Friction torque when rotating around local z-axis |
cid${}_{Fx}$ | ID of CURVE describing force versus displacement in local x-direction) |
cid${}_{Fy}$ | ID of CURVE describing force versus displacement in local y-direction) |
cid${}_{Fz}$ | ID of CURVE describing force versus displacement in local z-direction) |
Description
This command defines a joint between two rigid bodies or rigid connectors (see CONNECTOR_RIGID).
The joint is initially centered at the origin of csysid${}_1$. csysid${}_1$ also defines initial local directions in which the joint constraints are defined and forces/torques are output. csysid${}_2$ is used to define non-zero relative rotations at the initial state. csysid${}_2$ is only needed if the free rotations are limited or if rotational resistance is defined.
The joint rotation angle is defined as the rotation of enid${}_2$ minus the rotation of enid${}_1$. A non-zero initial rotation angle can be defined though csysid${}_1$ and csysid${}_2$.
Example
Joint
The following commands define a joint with ID 10 between the rigid parts with ID's 333 and 444. All rotations are free.
"this is a title"
10
P, 333, P, 444, XYZ, 0, 123
*COORDINATE_SYSTEM_FIXED
123, 4.0, 5.0, 6.0