Experimental Investigation of Non-Linear Coupled Vibrations in Elastic Columns Excited at High Frequencies

Abstract

Contributions intended for publication as Research Notes should be limited in length to 1000 words and two illustrations, and should be addressed to the Editor of Proceedings at the Institution Headquarters in London.

Coupling of flexual and longitudinal vibration modes has been observed experimentally in a slender column of rectangular cross-section subjected to periodic axial loading at frequencies up to 10 kHz; the fundamental longitudinal frequency of the specimen is 8·7 kHz. Resonance in the coupled flexural–longitudinal modes was observed when the frequency of axial excitation was 1, ½, and ⅓ times the fundamental longitudinal frequency. Strain levels at resonance in the coupled modes were comparable to strain levels in the purely flexural modes which were excited when the frequency of axial excitation corresponded to a flexural mode.