*LOAD_FORCE
"Optional title"
coid
entype, enid, direc, cid, $sf$, csysid, $t_{beg}$, $t_{end}$
"Optional title"
coid
entype, enid, direc, cid, $sf$, csysid, $t_{beg}$, $t_{end}$
Parameter definition
Variable | Description |
---|---|
coid | Command ID (optional) |
entype | Entity type (P only for rigid bodies) |
enid | Entity identification number |
direc | Force/moment direction |
cid | ID of a CURVE or FUNCTION defining force/moment versus time |
$sf$ | Force/moment scale factor |
csysid | Local coordinate system ID |
$t_{beg}$ | Start time |
$t_{end}$ | End time |
Description
This command is used to apply external forces to a node, to a set of nodes or to a rigid body. If the force is distributed to more than one node (entype = NS, G or FS), the contribution to each node is proportional to the node mass. That is, the force applied to a node $i$ is:
$F_i = \displaystyle{ \frac{m_i}{m_{tot}} F_{tot}}$
where $m_{tot}$ is the total mass of all nodes in the set and $F_{tot}$ is the total force.
Example
Load force
The following commands apply a force on node 111 in the local x-direction defined by coordinate system 222.
*LOAD_FORCE
N, 111, X, 123, 1.0, 222
*CURVE
123
0.0, 0.0
1.0, 1000.0
*COORDINATE_SYSTEM_FIXED
222, 0
1.0, 1.0, 0.0
N, 111, X, 123, 1.0, 222
*CURVE
123
0.0, 0.0
1.0, 1000.0
*COORDINATE_SYSTEM_FIXED
222, 0
1.0, 1.0, 0.0