Papers by Keyword: Piezoelectric Material

Abstract: The multi-physics of piezoelectric materials under different environmental conditions has been an active research subject for a few decades. Particularly, the thermoelastic behaviour of smart materials and structures is of great importance to their reliability in different applications. Traditionally, the Fourier heat conduction theory was introduced in dealing with the thermoelastic reactions of smart materials and structures. This may lead to reasonable analyses and useful guidelines in design of smart structures, especially when no severe thermal gradient is involved. However, when a severe thermal gradient is indeed involved in the service environment of a smart structure, the analysing results based on the Fourier heat conduction theory is unrealistic and usually rendered useless. Non-Fourier heat conduction theories have been introduced in the thermoelastic analysis of smart materials and structures in recent years and resulted in reasonable results. In this paper, we review the recent results of a thermopiezoelectric problem of a one-dimensional (1-D), finite length, functionally graded medium excited by a moving heat source using both the Fourier and Non-Fourier heat conduction theories. Numerical examples are displayed to illustrate the effects of non-homogeneity index, length and thermal relaxation time on the results.

Abstract: This work is concerned with the dispersion characteristics of Love waves propagating in a layered structure consisting of an anisotropic elastic layer and a piezoelectric half-space. The layer processes one symmetric plane, while the half-space is transversely isotropic. The explicit dispersion equation is derived. As an example, an inclined orthotropic material is chosen as an elastic layer to reveal the effect of material anisotropy on the dispersion behaviors. The numerical results show that the phase velocity is strongly influenced by the anisotropic degree.

Abstract: With the development of science and technology, the smaller sizes generator, the more attention by people. The main purpose of this article is to manufacture piezoelectric nanogenerator under micro vibration and its working principle is introduced and its performance is studied. The results show that, using the present nanomaterials, piezoelectric materials can be prepared. When its wind in copper laps, under the situation of micro pulse vibration its can turn into electrical energy, thus yield piezoelectric nanogenerators. In ambient vibration condition, piezoelectric materials produce larger rated current and voltage. However, copper laps cutting magnetic line of force produce less rated current and voltage. So the piezoelectric nanogenerators can be separately used to supply power. If multiple piezoelectric nanogenerator in tandem may produce higher voltage, current and power, which possess commercial value.

Abstract: A general purpose direct BEM code has been developed for three-dimensional crack problems in piezoelectric structures. Special 3D non-continuous crack tip elements and several techniques for determining crack tip parameters were implemented. To calculate the electromechanical energy release rate for a virtual crack extension, the θ-method is employed, which was originally suggested by BONNET for linear elastic materials. The paper presents the generalization and numerical realization of the θ-method to 3D piezoelectric cracks. The great advantage of the θ-method is the direct computation of energy release rate, whereas the way via K-factors and the IRWIN matrix is more complicated. The efficiency and accuracy of the technique are shown for various example problems by comparing with analytical solutions.

Abstract: Magnetoelectric(ME) effect in magnetoelectric laminate materials have potential application in many fields. In this paper, Fe78Si9B13 amorphous ribbons /PZT/amorphous ribbons sandwich structure laminate materials were fabricated. By theoretical analysis and experimental verification, we studied systemically on the characteristics of the magnetoelecric laminate materials, such as optimized bias magnetic field of the ME effect, ME voltage coefficient at low frequency and the resonant frequency of the magnetoelecric laminate element. ME effect can be used to develop new ac magnetic sensor and other devices.

Abstract: Since piezoelectric materials exhibit strong temperature dependency. The change of temperature results in marked variation of the PZT transducer’s electric impedance signals, which may lead to misjudgment of the structural health condition. A experiment was implemented on smart aggregates with embedded PZT transducers under 35°C, 45°C and 55°C three working conditions, and found that the temperature had significant influence on the electric admittance signals of embedded PZT transducers. The peak magnitudes of the admittance curves changed and the curves shifted leftward. Then a temperature compensation technique was used to minimize the temperature effects.

Abstract: Active vibration control based on fuzzy algorithm for piezoelectric smart plate is studied. After the characteristic of piezoelectric ceramic (PZT) is analyzed, modal and transient analysis are developed in this paper with finite element model of the piezoelectric smart plate constructed in ANSYS. Fuzzy logic control rules are established by the analysis of the deformation of the plate. With mode shape and displacement response curve obtained, active vibration suppression for the smart plate system is achieved by using commercial finite element programs. The simulation results illustrate that analysis of piezoelectric smart plate using ANSYS is practicable and the intelligent control method is effective.

Abstract: A kind of adaptive searching optimization active vibration control system of smart structure with piezoelectric materials was put forward, and the smart flexible cantilever structure was analyzed, the active vibration control system was realized in the lab. The result proved the methods’ feasibility and practicability.

Abstract: Many researchers have studied the harvesting from discarded energy such as solar energy, wind and vibration because of the exhaustion of fossil fuel and the environmental pollution. Particularly, vibration-based energy harvesting has increasingly received an attention in last decade. Therefore, the aim of study is to analyze the characteristics of piezoelectric materials to be used in the energy conversion system on vehicle road. At first, the dynamic loads of vehicle on the road are measured with respect to the weight and speed prior to analyzing the characteristics of piezoelectric materials. Then, the energy conversion amount of piezoelectric element is quantified for its size and type under the load profiles. The vehicle dynamic load is the average of 200kgf. The result indicates that the dynamic vehicle load is less affected by the speed. The generated voltage is 1.8kV, and extracted energy is 0.11mJ from one under the load of 8kgf applied on piezoelectric element. The power extracted from one passenger vehicle is able to operate a sensor and transmit acquisition data.

Abstract: Vibration control using combination of piezoelectric material and electrical circuits can remove the vibration energy from the host structure. The need for passive damping techniques arises to avoid the complexities and energy requirements associated with other vibration control techniques. Passive damping technique for reduction of vibration of structures by introduction of shunted piezoelectric patch is presented in this study. Finite element analysis is performed for a cantilever beam with shunted piezoelectric patch on it. The prediction of the model is validated against experimental published results. The obtained results demonstrate the feasibility of using piezoelectric patches with passive shunting as effective means for damping out the vibrations. The aim of this research work is the advancement of the coupled field analysis for structural vibration control with advanced methodology and to promote the design and analysis activities in the field of passive vibration control techniques using smart structures. Results obtained showed up to 86% reduction in the amplitude of the host structure which shows good agreement with published experimental results.