Modal Analysis of an Ultra-Flexible, Self-Rigidizing Toroidal Satellite Component

Over the past few years, much research has been performed on understanding the dynamics of an ultra-large, flexible toroidal satellite component subject to an internal pressure. However, the harsh environment of space is no place for inflated, membrane-like materials for fear of micro meteorite bombardment and subsequent puncture. Addressing this issue directly, United Applied Technologies (Huntsville, AL) has developed a novel, thin film casting approach to create a self-rigidizing torus. Once inflated, the torus structure is able to support its own shape, thus eliminating the need for any internal pressure. The self-rigidizing torus is extremely flexible, much more so than its pressurized predecessors. Such compliancy makes modal testing extremely difficult. However, through careful application of traditional modal testing techniques (shaker and accelerometer testing), the damped natural frequencies and mode shapes of the self-rigidizing torus can be discerned in the frequencies and mode shapes of the self-rigidizing torus can be discerned in the frequency bandwidth of interest, 1–12 Hz.