Technical Program Keynotes

Featured Speaker: Todd Rook Todd Rook

Friction-Induced Vibration and Effects of Vibration on Friction
Tuesday, September 20
10:40 a.m.

Understanding friction: where have we been, and where should we go next?
Since the time of ancient Egyptians, man has worked to conquer the resistive forces of friction. Early investigators such as DaVinci, Amonton and Coulomb laid the foundation of understanding friction which led to the commonly known Coulomb's law of friction the friction force is proportional to the normal force), which has evolved into the modern field of tribology. Yet after many centuries and innumerable researchers and papers, the current state of knowledge still distills down to that arcane law. Much of the work has involved coming up with empirical formulae for the proportionality constant (aka ยต) with respect to the different operating conditions (e.g. velocity, temperature, load etc.), yet this hasn't necessarily led to an increased understanding of the underlying mechanisms. If the purpose of gaining an understanding of friction (as with any physical phenomena) is to be able to dominate it, can we say we truly say we have such an understanding? The continued prevalence of friction generated problems (e.g. brake squeal) would suggest not. The next question is then, if we haven't arrived at a mastery of friction after all this time using the conventional paradigms, can we expect to master it anytime soon? What is the missing link to fulfill our understanding, and even if we can't arrive at a fundamental physics understanding, is there hope that we can we at least arrive at a sufficient "engineering" understanding to be able manipulate it enough to solve our problems?