Nonlinear Bow Friction

For this study, a simplified bow-string interaction model was implemented having the following characteristics:

• Static frictional ``release force'' is a multiple of the vertical bow force.
• Dynamic frictional force is small and fixed (independent of bow force).
• The ``capture force'' is somewhat smaller than the ``release force'' but also a multiple of the vertical bow force.
• One bit of state is maintained (``sticking'' vs. ``slipping'') in order to distinguish whether to use capture or release maximum forces.

The use of different maximum forces for release versus capture is motivated by the recent findings that there is evidence that the bow rosin melts during slipping and refreezes during sticking [10].