MODES
three inertias, one friction contact — which mode gets excited
MODES OF THE CHAIN
needs is the press force that mode requires before friction beats its own damping.
Lowest wins — it is not coupling alone. The heaviest mass is the one on the belt
(0.20 kg), and the 70 Hz mode is starved because its shape puts four times as much
motion on the lightest mass as anywhere else.
wall —k1— m1 —k2— m2 —k3— m3 on the belt.
Only m3 touches the belt, and it is the HEAVIEST — friction 0.20, shudder 0.10,
chirp 0.05 kg going inward. The extra inertias sit between the wall and the contact.