Experimental evidence of flutter and divergence instabilities induced by dry friction

Bigoni and Noselli experiment: Is it evidence for flutter in the Ziegler column?

“…Nevertheless, both results, that are purely academic (black curves) and theoretical but including some aspects of Bigoni's experiment (gray ones), are in qualitative agreement. Theoretical considerations of the modified (3-DOF) Ziegler-like column confirm the existence of the experimentally proved in [9] regions: stability, flutter and divergence versus growing load q. Some quantitative differences between both findings mainly concern the onset of flutter which appears for q below 3 in the column equipped with the roller.…”

“…Consider a Ziegler column in the version examined by Bigoni and Noselli [9] in their calculations. It is sort of a simplified system in which the rigid elements of the column, i.e.…”

“…1 Considered models: a Ziegler's column, b theoretical formulation [9] and c mechanism being tested in [9] By linearizing, one arrives at:…”

“…The authors and designers [9] conceived a tricky idea of making a mechanical system non-conservative and follower loaded. They added a perpendicularly oriented roller to the tip of the second arm of the Ziegler column and harnessed dry friction to do the final job.…”

“…The most important reference to the present paper is the experiment by Bigoni and Noselli [9] presented also in the form of a YouTube film and recommended as an evidence for flutter in the Ziegler column. In the following, we show the differences between the tested real mechanism and the Ziegler column in its original concept and formulation.…”