Dynamic Identification and control of Ultralight Deployable Space Structures

As space missions such as solar sails, reflector antennas and solar arrays increase in size, their dynamics become ever more important, since large deflections can lead to efficiency loss, damage, or stability loss. The first step in addressing these problems is the accurate identification of system dynamics, most notably vibration mode shapes, natural frequencies, and damping ratios. However, these systems often cannot be tested at full scale prior to deployment, and numerical simulations may overlook key components, such as the correct damping mechanisms. This problem is further intensified by the complexity of carbon fiber thin shells, which serve as the fundamental building blocks of ultralight deployable structures. For such systems, classical similitude methods such as dimensional analysis (DA) are inapplicable, since parameters such as shell thickness and the stiffness matrix cannot be experimentally scaled.

To address these challenges, I propose a data driven similitude method that exploits multiple scaled experiments to overcome the issue of distortion in partial similitude. In addition, to account for the inherent uncertainty in ultralight thin-shell structures, this method is extended into a Bayesian-inference-based statistical similitude model, which allows for uncertainty quantification in the acquired scaling law. The model is constructed from simulated data and updated based on experimental measurements, enabling statistical model updating of the scaling model. Finally, I present a stiff switching damping mechanism that leverages the tensioning typical of deployable space structures to actively suppress vibrations.

Bio:

Dr. Eyal Baruch is a Postdoctoral Scholar in the Space Structures Laboratory at Caltech, conducting research as part of the Space Solar Power Project (SSPP). He earned his Bachelor’s degree from Tel Aviv University, and  his Master’s and PhD degrees from the Technion.

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