Defesa de Tese - Arthur Adeodato (PPEMM)

CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA

DIRETORIA DE PESQUISA E PÓS-GRADUAÇÃO

DEPARTAMENTO DE PÓS-GRADUAÇÃO

COORDENADORIA DO PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA MECÂNICA E TECNOLOGIA DA MATERIAIS - PPEMM

A Coordenadoria do Programa de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais tem a satisfação de convidá-lo para assistir à 

 D E F E S A  D E TESE

 
COM O TÍTULO:

“SYNERGISTIC USE OF PIEZOELECTRIC MATERIALS AND SHAPE MEMORY ALLOYS FOR ENERGY HARVESTING: EXPERIMENTAL AND NUMERICAL ANALYSES”

 Por

Arthur Adeodato

Resume 

The seek for clean and renewable methods to obtain electrical energy is a global demand and experienced continued growth in the last two decades. Besides that, mechanical vibrations are considered a relevant kinetic energy resource and it is present in most environments. Piezoelectric materials arise as an alternative to convert mechanical vibrations into electrical power through the piezoelectric direct effect. Traditional piezoelectric harvesters present narrow bandwidth with great performance when external forcing frequency matches with harvester natural frequency, and therefore, the harvester operates in resonance condition. However, environmental vibration sources can vary its frequency in a wide range promoting a significant drop in the harvester performance. Based on that, nonlinear dynamical responses have been explored as an alternative to increase piezoelectric energy harvesters’ operational range. In addition, shape memory alloys (SMAs) present nonlinear thermomechanical coupling and the intrinsic characteristic to change mechanical properties due to solid phase transformation induced by either temperature and mechanical fields. This work investigates the synergistic use of piezoelectric materials and the nonlinear constitutive behavior of shape memory alloys with the aim to provide adaptability characteristics and increase the harvester operational range. A constitutive model with assumed kinetic phase transformation is developed to describe the SMA constitutive behavior in dynamical conditions. An experimental apparatus is built to characterize the dynamical behavior of a SMA-piezoelectric energy harvester and evaluate the harvester in operational conditions. The analyses consider the influence of SMA phase transformation induced by temperature and mechanical load separately and evaluate the frequency response of the SMApiezoelectric harvester in different conditions of use. Afterward, a good theoretical-experimental correlation is found. Results reveal that the addition of a SMA element in a piezoelectric energyharvester is able to alter its frequency response and increase the operational range via thermal and mechanical stimulus.

Keywords: Energy Harvesting, Piezoelectric Materials, Shape Memory Alloys, Experimental

BANCA
Prof. Pedro Manuel Calas Lopes Pacheco - CEFET/RJ (orientador)
Prof.  Luciana Loureiro da Silva Monteiro - CEFET/RJ (orientador)
Prof.  Ricardo Alexandre Amar de Aguiar - CEFET/RJ
Prof.  Marcelo Amorim Savi - COPPE/UFRJ
Prof. Aline Souza de Paula - Universidade de Brasília - UnB
Prof. Carlos de Marqui Júnior - Escola de Engenharia de São Carlos - EESC USP