<DOC>
<DOCNO>
515
</DOCNO>
<TITLE>
self sustained oscillations of a system with non-linear
damping of a particular type .
</TITLE>
<AUTHOR>
neumark,s.
</AUTHOR>
<BIBLIO>
rae tn.aero.2839, 1962.
</BIBLIO>
<TEXT>
  the paper deals with self-sustained
oscillations of a dynamic system
of single degree of freedom, with linear
restoring force and non-linear
damping force .  the latter is supposed
to be a function of velocity
representable by a simple /polygonal/
graph, such that the damping is
negative at small velocities but becomes
positive at velocities above a
certain value .  on these assumptions,
a rigorous solution is presented,
including the equations of motion,
amplitude, maximum velocity and period .
a very simple solution is obtained
for the limiting case of vanishingly
small damping .  an approximate solution
by series in powers of damping
ratio is worked out which
gives a satisfactory accuracy for
quite large values of .
</TEXT>
</DOC>
