Identification of slider/disk contacts using the energy of the acoustic emission signal

The take-off behavior of typical tri-pad and sub-ambient pressure tri-pad sliders is investigated using acoustic emission (AE) measurements. The relative energy of the torsional and bending mode frequencies in the AE signal is determined as a function of velocity. The change in energy in the AE signal corresponding to the torsional and bending modes of vibration of the slider is found to be associated with the change in the contact location between slider and disk from the side rails to the trailing edge.