Expanding the teaching of single frequency vibration absorption to broadband attenuation using subordinate oscillator arrays via fettuccine pasta

Abstract

Dynamic vibration absorbers (DVAs) and tuned mass-dampers (TVAs) have widespread applications in the aerospace industry, the automotive sector, and in civil engineering structures. There are numerous designs of active and passive vibration attenuators or absorbers that isolate structural vibrations at or around the desired frequency. All these design approaches are fundamentally different ways to modify and tune the placement of the resonant frequencies of the host structure. The current work presents a novel method to passively attenuate vibration over a broad frequency bandwidth in the presence of uncertainty. An array of linear oscillators, also referred to as subordinate oscillator arrays (SOAs), are attached to a two-degrees-of-freedom structure to produce an attenuated broadband frequency response around a target frequency. SOAs can also be interpreted as an array of DVAs and in some categories, they can be considered as an approach to meta-structures. Another objective of the current work is to develop a hands-on approach to extend classroom teaching of vibration-isolation using SOAs made out of fettuccine strands and modeling clay. The frequencies of the oscillators in the array are tuned by varying the length of each strand and the mass of the modeling clay attached to its tip. Uncertainty in dynamic properties of such oscillators often results in mistuned SOAs with non-uniform frequency response function. Therefore, designing and testing fettuccine-based SOAs allows students to handle cases when structural uncertainties arise in engineering systems. Additionally, some of the work in the field of meta-structures can be modeled and represented by SOAs and this will provide a straight forward way to teach students some of these contemporary concepts.