Nasser Saber
PhD Candidate, School of Engineering, Univeristy of South Australia
BSAC Visiting Researcher
October 15, 2013 | 12:30 to 01:30 | 540 Cory Hall
Host: Richard White
Piezoelectric composites comprising an active phase of ferroelectric ceramic and a polymer matrix have recently attracted numerous sensory applications. With the increasing demand on monitoring pipeline infrastructures, it is of great importance to develop flexible sensors made of multi-phase materials, more advantageous over conventional one-phase rigid ceramic sensing blocks, for monitoring vibrations and detecting structural damages. These composites can reduce the acoustic impedance mismatch between the sensor and the host structure, contributing to a more efficient transmission of elastic wave from the structure to the sensor and hence an improved damage-detection capacity. The composite sensors, permanently covering the specified areas of a host structure surface, can be used in ultrasonic and acoustic emission monitoring techniques. The working principle is based on the fact that every degradation mechanism emits a specific and identifiable acoustic waveform under the quasi-static and dynamic loading regimes of typical pipeline operating conditions. The introduced sensing system is designed to capture these incoming elastic wave fields based on the inverse piezoelectric effect of PZT particles in a protective, insulating polymer matrix. We recently investigated the incorporation of graphene platelets (GnPs) and multi-walled carbon nanotubes (MWNTs) into PZT/epoxy composites to produce three-phase piezoelectric composites. The nanocomposite films showed improved piezoelectric coefficients and electromechanical responses besides an enhancement in stiffness, motivating more study of nanoadditives in piezoelectric composites for sensing applications.
people.unisa.edu.au/nasser.saber
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