Response shaping using a subordinate oscillator array

Abstract

Recent research has shown that arrays of small dynamic elements attached to a master structure can be tuned to significantly alter the time or frequency response of the system. Colloquially known as “fuzzy structures,” subordinate oscillators have led to applications including damping, radio frequency filtering, energy harvesting, and micro electro-mechanical system (MEMS) chemical vapor sensing. A passive machinery damping system will be designed and tested for silencing properties. The current subordinate oscillator array (SOA) design consists of a plate of sheet metal with arrays of cantilevers machined of similar but different lengths. These cantilevers will have a range of natural frequencies, which correspond to a desired frequency suppression range. When the SOA is mounted to a vibration source, it functions as an acoustic meta-material which traps and dissipates energy. This is accomplished by synchronizing the phase and frequency of the cantilevers with machinery peak amplitude frequencies. By designing cantilevers properly, the SOA acts as a mechanical broadband filter as opposed to a notch filter. The SOA will be tested primarily for vibration suppression performance but also for sensitivity to tolerance and energy storage density.