Command manual

Command list

LOAD_FORCE

Loads
*LOAD_FORCE
"Optional title"
coid
entype, enid, direc, cid, $sf$, csysid, $t_{beg}$, $t_{end}$

Parameter definition

VariableDescription
coid Command ID (optional)
entype Entity type (P only for rigid bodies)
options: N, NS, G, FS, P
enid Entity identification number
direc Force/moment direction
options: X, Y, Z, RX, RY, RZ
cid ID of a CURVE or FUNCTION defining force/moment versus time
$sf$ Force/moment scale factor
default: 1
csysid Local coordinate system ID
default: global coordinates are used
$t_{beg}$ Start time
$t_{end}$ End time
default: 1.0e10

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