Computational and experimental study on dynamic instability of extended bistable carbon/epoxy booms subjected to bending

Bistable reeled composite booms (BRCs) constructed from braided carbon/epoxy plies are suitable candidates for use as extendible booms or as elements of large deployable space structures. However, without modification, BRCs have an open section which limits their torsional stiffness, and makes them prone to collapse under low bending moments. In this study a “roll-up” deployable photovoltaic (PV) solar array with two side-by-side extendible BRCs is used as a case study to analyse the dynamic behaviour of BRCs on spacecraft undergoing rotational manoeuvres numerically. The BRCs have rotational accelerations applied to their roots to simulate the effect of being attached to a manoeuvring spacecraft. Budiansky-Hutchinson criterion is used to define an instability failure point based on a change in cross-sectional shape. This was used to estimate the maximum angular acceleration. While it is extremely difficult to replicate the behaviour of a large flexible lightweight structure in microgravity on the ground, an experiment to determine the point of collapse of BRCs under gravity were used to verify the simulation results.