A cylindrical joint is like a rigid body, except that one specific direction is
defined with the first two slave nodes. All nodes are free to move along this direction and
to rotate around it.
A kinetic condition is applied on all slave nodes, including the first two defining the
privileged direction No master node is used. Figure 1. Cylindrical Joint
If all the slave nodes are initially aligned, they will always remain aligned. As visualized in
Figure 1, the rotation freedom is a local rotation for each node and not a
global rotation around axis 1-2. Therefore, it is recommended to use a cylindrical joint
with aligned nodes. Figure 2. Door Hinge Example
Figure 2 shows how a hinge
could be modeled using a cylindrical joint. The cylindrical joint is made of nodes 2, 5,
3 and 4. Note that in hinge modeling nodes must be aligned to get a realistic rotation,
then beams or any other finite elements are used to connect nodes 1-2, 2-5, 4-3 and
nodes 3-6. Finally, it is possible to link nodes 2-3 with a nonlinear elastic spring to
improve the connection. Figure 3. Hinge Modelization
