Dm. Photiadis et al., WAVE-NUMBER SPACE RESPONSE OF A NEAR PERIODICALLY RIBBED SHELL, The Journal of the Acoustical Society of America, 101(2), 1997, pp. 877-886
Employing near-field acoustic holography measurements, the wave-number
space response of a ribbed shell to a point drive is investigated. Th
e data show the dominance of flexural vibration in the mid-frequency r
ange, and demonstrate the prominent role played by the eigensolutions
of the periodic structure. The supersonic region of frequency-wave-num
ber space is examined in detail and the fast membrane waves, although
suppressed in level relative to the subsonic bending waves, provide a
clear highlight in this domain at frequencies below the first radiatin
g flexural passband. The results are also examined in k(z)-k(phi) spac
e for several frequencies. This representation enables an interpretati
on of the results in terms of the slowness surface of the flexural wav
es and provides a simple explanation for the various complex beaming a
nd focusing phenemena which occur in this system.