| Attributes |
|---|
| Type |
spider element |
| Physical property |
Smooth Body Motion Property |
| Mesh connectivity |
SPIDER |
| Number of nodes |
1 slave, n-1 masters |
| Degrees of freedom
(per node) |
6 (3 translations and 3 rotations) |
| Type of behavior |
kinematics |
The displacement of the slave node (N1) is
linked to the displacement of the center of gravity of the n-1 master
nodes. This linkage does not introduce any additional stiffness between the
master nodes.
The relations are obtained in the following way:
- Compute the center of gravity of the master nodes using the same
weight for all the nodes. The average displacement (translations and rotations) of the center of
gravity of the master nodes is computed using the Mean Squares method.
- The slave node is linked to the center of gravity of the n-1 master
nodes according to the rigid-body equations.
The master nodes should not be aligned, otherwise the
rotation along the axis of alignment can not be transmitted.