This component is a linear damper, which acts
as a line force between frame_a and
frame_b (i.e. point-to-point). A force
f is exerted on the origin of frame_b and
with opposite sign on the origin of frame_a along the
line from the origin of frame_a to the origin of
frame_b according to the equation:
f = d*der(s);
where d is the damping constant,
s is the distance between the origin of
frame_a and origin of frame_b, and
der(s) is the time derivative
of s.
In the following figure a typical animation is shown where a mass is hanging on a damper.

Developed 2010 at the DLR Institute of System
Dynamics and Control