Experimental Measurement of Picometer Scale Spontaneous Vibrations in a Precision Deployable Boom under Thermal Loading

This paper reports observations and analysis of picometer scale spontaneous vibrations in a precision deployable boom under thermal loading. The structural test article is a deployable boom previously flown in space. It exhibited spontaneous vibrations during the temperature rise following a night to day transition on orbit. In an attempt to reproduce the spontaneous vibrations on the ground, the test article was thermally loaded within a mechanically stabilized test environment. Spontaneous vibrations were induced in these ground experiments. The vibrations were at a scale of motion for which current theories would not expect such a release. The amplitudes of these vibrations were on the order of a few dozen picometers, and the frequency was near 1500 Hz. Evidence of wave dispersion was detected in the vibrations