The not-so-simple harmonic oscillator

A model inspired by the behavior of a simple harmonic oscillator subject to dry sliding friction is applied to the damping of a variety of mechanical oscillators. In contrast to the conventional model of damping in mechanical systems, the new model predicts a logarithmic decrement of the motion which is quadratic in the period. This prediction agrees well with the observed period dependence of the long-period physical pendulum which was the primary focus of this investigation. (C) 1997 American Association of Physics Teachers.