From a comparison of the vibration spectrum of the flexural mode and the vibration spectrum of the torsional mode , it can be observed that {HEAD ~ more high harmonic force components} are excited in {TAIL ~ the torsional mode} with better signal to noise ratio 
are excited in
From a comparison of the vibration spectrum of the flexural mode and the vibration spectrum of the torsional mode , it can be observed that { HEAD ~ more high harmonic force components } are excited in { TAIL ~ the torsional mode } with better signal to noise ratio
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH