A dynamic model of percussive drilling assuming a dry friction mechanism to
explain the experimentally observed drop in penetration rate is presented.
The inherent nonlinearity of the discontinuous impact process is modelled
as a frictional pair, and this can generate the pattern of the impact force
s close to reality. Despite quite radical simplifying assumptions, the mode
l is able do describe the fall of material removal rate for a higher static
loading with a good agreement to experimental investigations. (C) 2000 Els
evier Science Ltd. All rights reserved.