Aplicação do Coeficiente de Hurst na Técnica de Monitoramento da Integridade Estrutural Baseada na Impedância Eletromecânica

Abstract

This work presents the use of Hurst coefficient in structural health monitoring based on electromechanical impedance method. This method uses piezoelectric sensors coupled to the structure in order to detect impedance signatures changes that may be related to the presence of damage. The damage metrics are parameters used to quantify the changes in impedance signatures, which presents values very close to zero in structural no-damage condition and increases significantly as the damage becomes present. The Hurst coefficient will be presented and discussed as a new damage metric to assess changes in impedance signatures due to the presence of damage, in addition to the damage metrics already consolidated in the literature. To evaluate the effectiveness of Hurst coefficient in damage detection, a set of experiments were carried out on aluminum beams, submitted to tests without the presence of damage and with the presence of damage at different temperatures. The damage analysis is performed considering the comparison of the values obtained from Hurst with the existing damage metrics. The results show that the Hurst coefficient as a damage metric allows to detect the presence of damage in all test conditions, allowing to present and conclude on the advantages and disadvantages of the Hurst method in electromechanical impedance.