A viscoelastic harvester-absorber for energy generation and vibration control

Abstract

A vibration energy harvester harnesses the oscillatory movement andconverts it into electrical energy. On the other hand, a (dynamic) vibration absorberdissipates the mechanical energy of a host structure (primary system). The proposal fora harvester-absorber device (HAD), comprinsing a piezoelectric element (conventionalharvester) bonded with a viscoelastic layer and a steel constrained layer, is based on thedual purpose of generating energy and at the same time reducing the vibratory responseof the primary system. Introducing a viscoelastic dissipative layer in a conventionalharvester, also offers the advantage of simultaneously reducing wear on the piezoelectricelement, thereby extending its lifespan and preventing fatigue-related breakage. Thepaper presents a model of a harvester-absorber built from a bimorph piezoelectricbeam, a layer of viscoelastic material (E-A-R C1002-01PSA) and a beam of steel, whichacts as a constrained layer. A lumped parameter model is proposed for the theoreticaldescription of the HAD which is successfully used to experimentally determine itsparameters. After that, and using the equivalent stiffness concept, the HAD wascoupled to a free-free beam with two masses at its ends to study its perfomance over areal host structure. The inertance of the composite system and voltage/force frequencyresponse function of the HAD were obtained and compared with experimental results.The accuracy of the results justifies and validate the model which has the advantageof simplicity and can contribute to reducing wear and increasing the lifespan of brittlepiezoelectric structures.