Typically, the Electromechanical Impedance (EMI) technique does not use an analytical model for basic damage identification. However, an accurate model is necessary for getting more information about any damage. In this paper, an EMI model is presented for predicting the electromechanical impedance of a cracked beam structure quantitatively. A coupled system of a cracked Timoshenko beam with a ...

Commercial lead zirconate titanate (PZT) perovskite powders were used to fabricate ceramic tape and then sintered by microwave and conventional methods. Both dielectric and piezoelectric properties of PZT ceramic tapes were studied in terms of sintering process. X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) show the PZT perovskite phase with smaller grain size and dens...

The surface morphology and microstructure of laser-ablated Pb~Zr0.52Ti0.48!O3 ~PZT! films on a ~100! SrTiO3 ~STO! substrate at early growth stage are characterized by means of atomic-force microscope, x-ray diffraction, and high-resolution transmission electron microscopy analysis. The ~100! STO surface is found to be very favorable for epitaxial growth of ~001! PZT films, which undergo a three...

The electromechanical (EM) impedance technique using piezoelectric lead zirconate titanate (PZT) transducers for structural health monitoring (SHM) has attracted considerable attention in various engineering fields. In the conventional EM impedance technique, the EM admittance of a PZT transducer is used as a damage indicator. Statistical analysis methods such as root mean square deviation (RMS...

Capacitive micromachined ultrasound transducers (cMUTs) have emerged as a leading area of research because these devices are non-resonant and can be integrated along with signal processing electronics. However, few publications discuss cMUT arrays packaged in a handheld probe capable of generating realtime ultrasound images. This paper presents real-time in-vivo images from a cMUT linear array ...

Experimental testing is a major source of data to quantify the tolerance of the human body to impact and to develop protection strategies. Correlating the time of rib fractures with the kinematics of the occupant and the action of safety systems would provide valuable data for assessing safety systems and developing injury risk functions. However, methods for determining rib fractures timing ar...

A thermodynamic formalism is developed to calculate the pyroelectric coefficients of epitaxial ~001! Ba0.6Sr0.4TiO3 ~BST 60/40! and Pb0.5Zr0.5O3 ~PZT 50/50! thin films on ~001! LaAlO3 , 0.29 LaAlO3 :0.35(Sr2TaAlO6) ~LSAT!, MgO, Si, and SrTiO3 substrates as a function of film thickness by taking into account the formation of misfit dislocations at the growth temperature. The role of internal str...

Piezoresponse force microscopy (PFM) technique has been utilized to study the evolution of domain structure with varying PbsZr,TidO3sPZTd thickness on GaN substrate. Sol-gel PZT films were deposited on the GaN/sapphire substrate with PZT thickness of 100, 200, and 300 nm. The films exhibit ferroelectric properties that vary as a function of the film thickness. This is explained by the mechanica...

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 ...