Theory 002/Acoustics & Vibration

Damping Is Joint Slip

The claim

Structural damping in bolted assemblies is set by micro-slip amplitude at joints rather than by material loss factors.

01The mechanism

Energy leaves through friction at interfaces, so damping scales with the number of slipped joints and the amplitude of slip, not with bulk material damping.

02Predictions

P1Damping should rise with joint count at fixed material.
P2Tightening joints should reduce damping until slip vanishes.

03Refutation

Damping independent of joint condition would favour material loss.