Full-field laser vibrometer study of dissipation in a beam with a coupled oscillator array

Abstract

Coupled oscillator systems can be designed to manage the distribution of mechanical energy in vibration or acoustic systems. A specific implementation of an array composed of small damped mass-spring attachments on a primary is here referred to as a subordinate oscillator array. SOAs and their ability to absorb energy from a primary mass are of continued importance in analysis for both structural and acoustic systems. The ability to dissipate energy in a specific frequency band has many potential applications. This work will use laser Doppler vibrometry (LDV) to evaluate a beam mounted on an electromechanical shaker with and without an attached planar SOA composed of much smaller beams. This study is motivated by earlier work that indicated a high sensitivity to disorder in the form of fabrication error. The apparatus allows for the controlled introduction of various levels of disorder to quantify its effect and compare to a numerical model. We will show full-field forced response from the LDV with and without the SOA and the resulting apparent damping within the band of the SOA for various levels of disorder.