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Nonlinear Oscillations
Most oscillation systems are really nonlinear, and linear oscillations are the exceptions. If the
restoring force deviates from a linear dependence in the displacement or if the damping force is
nonlinear in the velocity, the motion about a point of stable equilibrium is no longer linear and the
motion is anharmonic or nonlinear. The general equation of motion for such a system is, for the one-
dimensional case, a nonlinear differential equation of the following form:
mx gx fx
() ()
. (9.1)
Here, f(x), the restoring force, is not proportional to x;
, the damping term, is not ...