This paper studies dynamic stability of functionally graded beams with piezoelectric layers subjected to periodic axial compressive load that is simply supported at both ends lies on a continuous elastic foundation. The Young’s modulus of beam is assumed to be graded continuously across the beam thickness. Applying the Hamilton’s principle, the governing dynamic equation is established. The eff...

Crack detection using piezoelectric sensors have widely been reported in many research papers. In most of these studies, the cracks considered are generally artificially induced and the piezoelectric sensors are not subjected to fatigue loading. This paper presents a set of fatigue tests results demonstrating the effectiveness of piezoelectric elements in crack detection. The results presented ...

The paper reviews the recent applications of piezoelectric materials in structural health monitoring and repair conducted by the authors. First, commonly used piezoelectric materials in structural health monitoring and structure repair are introduced. The analysis of plain piezoelectric sensors and actuators and interdigital transducer and their applications in beam, plate and pipe structures f...

Wave propagation in composite structures with shunted piezoelectric patches is investigated in this work. The Wave Finite Element(WFE) approach is firstly developed as a prediction tool for wave propagation characteristics like dispersion curves in composite structures, and subsequently extended to consider shunted piezoelectric elements through the Diffusion Matrix Model(DMM). A three-layered ...

In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device w...

Degradation of piezoelectric properties has been studied in ferroelectric PZT films by means of optical interferometry. The degradation under dc bias and aging of poled films have been observed. The decay of piezoelectric coefficient with time is described by a logarithmic law with aging rates comparable to those of switching polarization. The aging rates are shown to be sensitive to poling con...

This paper proposes a simple interface circuit enabling resonant frequency tuning of highly coupled piezoelectric harvesters. This work relies on an active AC/DC architecture that introduces a tunable short-circuit sequence in order to control the phase between the piezoelectric current and voltage, allowing the emulation of a capacitive load. It is notably shown that this short-circuit time in...

Direct tensile mechanical loading of an individual single-crystal BaTiO(3) nanowire was realized to reveal the direct piezoelectric effect in the nanowire. Periodic voltage generation from the nanowire was produced by a periodically varying tensile mechanical strain applied with a precision mechanical testing stage. The measured voltage generation from the nanowire was found to be directly prop...

The piezoelectric properties of [001](c) poled 0.94Pb(Zn(13)Nb(23))O(3)-0.06PbTiO(3) single crystals were greatly enhanced by controlling their domain configurations. Contrary to the interpretation of charged domain walls being the main contributor to the piezoelectric enhancement, we found that smaller domain size and more neutral domain walls were the main contributors for the piezoelectric e...

Piezoelectric materials are used in many engineering application. When modeling piezoelectric materials the standard assumption is that the electromagnetic field which is used to actuate the piezoelectric material is quasi static. In this paper we show that although the assumption of a quasi static electrical field is valid when one is interested in simulating a piezoelectric material, this ass...