International Journal of Applied Electromagnetics and Mechanics - Volume 31, issue 1

Authors: Chen, Jiankang | Wang, Wencai | Yang, Zengtao | Wang, Ji | Yang, Jiashi

Article Type: Research Article

Abstract: We perform a theoretical analysis on a vibratory gyroscope consisting of a concentrated mass connected to two orthogonal piezoelectric rods in extensional vibration. The analysis is more refined than a previous one in that the bending stiffness of the rods and the rotatory inertia of the mass are included. It is shown that when these effects are considered, the behavior of the gyroscope is affected in a fundamental way. The gyroscope has an output even when …it is not rotating, and the output is sensitive to the rotatory inertia of the mass. Show more

Keywords: Piezoelectricity, gyroscope

DOI: 10.3233/JAE-2009-1043

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 1-8, 2009

Authors: Zhu, Kongjun | Qiu, Jinhao | Ji, Hongli | Totsuka, Atsushi

Article Type: Research Article

Abstract: In this study, three types of BaTiO_{3} powders with different particle sizes synthesized by hydrothermal method were used to fabricate the lead-free barium titanate piezoelectric ceramics. The BaTiO_{3} ceramics from these three types of BaTiO_{3} powders were sintered at different temperature (1150–1350°C) using traditional sintering method, and their piezoelectric properties were investigated and compared. The results indicate that the BaTiO_{3} piezoelectric ceramics from BT03 …powder exhibit highest d_{33} value (over 350 pC/N). The reasons were also investigated by comparing the properties of three kinds of BaTiO_{3} powders and their compacts sintered at different temperature. Show more

Keywords: Barium titanate, hydrothermal method, lead-free, ceramics, piezoelectric property

DOI: 10.3233/JAE-2009-1041

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 9-16, 2009

Authors: Wu, Jian | Yuan, Shenfang | Shang, Yin | Wang, Zilong

Article Type: Research Article

Abstract: This paper presents a dedicated wireless sensor node for strain distribution monitoring, three functional modules are designed respectively, including sensor input unit, processing core, and wireless communication. The multi-channel strain gauge signal conditioning circuit is designed on the sensor input unit for multi-point strain distribution monitoring requirement and proved to be accurate and reliable. A miniature, lightweight, and shock-proof aluminum encapsulation is also designed especially for aerospace structural health monitoring (SHM) application. …To verify the functionality of the designed wireless sensor node for SHM capability, a multi-point strain distribution monitoring system is developed on a aircraft carbon fiber reinforced plastic (CFRP) wing box. The strain gauges array is stuck to the inner surface of the CFRP wainscot and used to monitoring multi-point strain distribution. The reliable wireless sensor network is deployed adopting the designed wireless sensor nodes to gather, process, and transmit strain gauges signals and monitoring results. An embedding pattern matching method and a directed diffusion routing algorithm are developed to monitor the strain distribution successfully for the actual big CFRP wainscot. Show more

Keywords: Multi-point strain distribution, CFRP wing box wainscot, Structural health monitoring, Wireless sensor network

DOI: 10.3233/JAE-2009-1042

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 17-28, 2009

Authors: Gabbert, U. | Lefèvre, J. | Laugwitz, F. | Nestorović, T.

Article Type: Research Article

Abstract: The paper presents an overall numerical approach for the simulation and design of smart lightweight structures in order to control vibration and noise. The design process requires an overall virtual computer model, which includes the passive mechanical structure, the acoustic fluid, the active materials, such as piezoelectric patch actuators glued to the structure, as well as the controller. Based on the finite element method such an overall model is presented in the paper. An acoustic box …is used to verify the computational approach by comparing simulated and measured results. Show more

DOI: 10.3233/JAE-2009-1044

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 29-39, 2009

Authors: Guyomar, D. | Sebald, G.

Article Type: Research Article

Abstract: In this paper, we investigated the Electrothermal conversion of ferroelectric materials. The key parameters for cooling and energy scavenging were identified: n the framework of pyroelectric energy harvesting, first results using SSD technique showed a magnification of the voltage by a factor of 2. We believed that the use of films could increase the power by a factor of 10–100. Currents works with PVDF films is being held in the laboratory. In the framework of electrocaloric refrigeration, we believe that ultrahigh efficiency cooling devices may be designed. However, the main limitation now is the maximal temperature of 1–2 K controllable …by the electric field. Further work with small thicknesses (fibres, thin and thick films) will be interesting due to the very high possible electric fields. Show more

DOI: 10.3233/JAE-2009-1045

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 41-46, 2009

Authors: Tsaur, Deng-How | Chang, Kao-Hao

Article Type: Research Article

Abstract: The problem of TE-wave scattering by a shallow circular channel in a perfectly conducting plane is considered and its rigorous series solution is also derived. By the region-matching technique, a semi-circular auxiliary boundary is introduced to divide the analyzed region into two subregions. The magnetic field of each subregion is represented in terms of an infinite series of wavefunctions with unknown coefficients. To include more practical applications, the wave source is assumed to be a Gaussian …beam. The Kozaki's approximate expansion for Gaussian-beam incidence is adopted, which can convert into the plane-wave expansion with a special condition. With the enforcement of interface continuity conditions and the satisfaction of the channel surface boundary condition through the Graf's addition formula, the unknown expansion coefficients are determined. Comparisons for the semi-circular channel case with available data in the literature indicate excellent agreement. Pronounced effects of the depth-to-half-width ratio of the channel on backscattering width, far-field radiation pattern and equi-amplitude distribution of the magnetic field are illustrated by graphical results. The flexible and tunable features of the presented geometry make it easily applicable to the design and fabrication of multiple finite channels for optical devices. Show more

Keywords: electromagnetic scattering, shallow circular channel

DOI: 10.3233/JAE-2009-1046

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 31, no. 1, pp. 47-59, 2009