The electro-mechanical impedance method for damage identification in circular plates (original) (raw)

Non-destructive measurements of an electromechanical impedance allow for the effective assessment of the state of mechanical structures. Piezoelectric transducers, which are distributed in monitored construction, introduce coupling between mechanical properties and directly measured electric entities. Therefore incipient mechanical damage can be detected and its growth followed. The changes of mechanical properties are found with the comparison between plots of impedances measured for both original healthy system and the system which is operating in a current state. This paper presents the results of Finite Element analyses performed for a cantilever aluminium beam with bonded piezoelectric transducer. Modelled structure was excited to vibrate at high frequency range and electromechanical impedance plots were obtained from the harmonic analysis. Vertical notch was introduced in the beam and the damage metrics were used to asses qualitative changes in structural properties of the system. The numerical results were confirmed experimentally using laboratory equipment. With obtained numerical and experimental results there has been introduced the idea of a Structural Health Monitoring (SHM) system.