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BELL SYSTEM TECHNICAL JOURNAL 



the motion is along the x axis, though there is a certain amount of lateral 

 contraction as the plate elongates. 



The second harmonic will have the same resonant frequency if ^ = lir, 

 the third if ^ = Stt, etc. 



1^ 



J3 



<b 2 



kb 



Fig. 7.8 — 6-b versus ^-^ for plate longitudinal modes ( ^ = -33, k = , tt j 



L> 



Fig. 7.9 — Distortion of plate vibrating in first longitudinal mode 



In addition to harmonic modes along the length just considered there 

 will be those for which the motion breaks up along the width. In general, 

 the distortion of the plate may be quite complex with simultaneous variations 

 along both dimensions. Similarly, for plates such as shown in Fig. 7.5 



