This paper presents finding from a recent set of formal performance assessments studies, quantifying the ability of a hybrid passive/active SHM system to detect impact damage. The SHM system itself is an integrated device including an array of PZT sensors with a central PZT actuator, analog-to-digital converter, memory and FPGA. In passive mode, the system uses the central PZT element for trigg...

Macroscopic constitutive relations based on the mean-field theory and the Mori–Tanaka method are derived for a 3-phase composite consisting of a polymer matrix and shape memory alloy (SMA) and piezoceramic (PZT) inclusions. Effective moduli are computed for likewise oriented spherical and cylindrical inclusions. Results are also computed for cylindrical PZT and ellipsoidal SMA inclusions. Even ...

During the construction of a concrete structure, strength monitoring is important to ensure the safety of both personnel and the structure. Furthermore, to increase the efficiency of in situ casting or precast of concrete, determining the optimal time of demolding is important for concrete suppliers. Surface bonded lead zirconate titanate (PZT) transducers have been used for damage detection an...

This paper presents the development of tactile sensors using the sol-gel process to deposit a PZT thin-film from 250 nm to 1 μm on a flexible stainless steel substrate. The PZT thin-film tactile sensor can be used to measure human pulses from several areas, including carotid, brachial, finger, ankle, radial artery, and the apical region. Flexible PZT tactile sensors can overcome the diverse top...

A ceramic–ceramic actuator composed of two piezoelectric ceramic layers with opposite poling directions was developed. One layer of the actuator had a high coercive electric field (PZT (Pb(Zr,Ti)O3)-I; Ec5 1.1 kV/mm), while the other had a relatively low coercive electric field (PZT-II; Ec5 0.6 kV/mm). The actuator was fabricated by cofiring a green compact composed of the PZT-I powder on top o...

Piezoelectric PbZr(0.52)Ti(0.48)O(3) (PZT) thin films deposited on thin glass substrates have been proposed for adjustable optics in future x-ray telescopes. The light weight of these x-ray optics enables large collecting areas, while the capability to correct mirror figure errors with the PZT thin film will allow much higher imaging resolution than possible with conventional lightweight optics...

The electro-mechanical (E/M) impedance response of a 1-D structure interrogated by a PZT wafer active sensor is modeled from first principles. Equations of motion for the flexural vibrations under moment excitation from the PZT wafer are developed. Solution in terms of normal modes with internal damping is obtained. General expressions for pointwise dynamic stiffness and pointwise dynamic compl...

Experimental testing is a major source of data to quantify the tolerance of the human body to impact and to develop protection strategies. In the field of vehicle safety, it has been demonstrated that chest injuries are a good predictor of an impact severity. Correlating the time of rib fractures with the kinematics of the occupant and the action of safety systems would provide valuable data fo...