International Journal of Applied Electromagnetics and Mechanics - Volume 33, issue 3-4

Authors: Liu, Jian | Qiu, Jinhao | Chang, Weijie | Ji, Hongli | Zhu, Kongjun

Article Type: Research Article

Abstract: This paper presents an approach for acousto-ultrasonic source (passive damage or impact) localization based on metal core piezoelectric fiber (MPF) rosettes. MPF is a new type piezoelectric ceramic device with small size and has high directivity to sense Lamb waves. The response of surface-bonded MPF sensors to Lamb-wave fields is explored theoretically and experimentally. The good directional properties of MPF are used to determine the direction of propagation of the acoustic waves by mounting three MPF …sensors in a rosette configuration. Two suitably spaced rosettes are used to locate the source of the ultrasound by taking the intersection of the direction given by each rosette. The performance of the rosettes for source location is validated on an aluminum plate. Show more

Keywords: Metal core piezoelectric fiber (MPF), Damage location, Lamb waves, Structural health monitoring

DOI: 10.3233/JAE-2010-1196

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 865-873, 2010

Authors: Sasaki, Minoru | Onouchi, Yusuke | Ozeki, Tomohito | Tamagawa, Hirohisa | Ito, Satoshi

Article Type: Research Article

Abstract: This paper presents methods of end point motion control of an Ionic Polymer-Metal Composite actuator. Feedforward control with the inverse system is used. Through frequency analysis of the IPMC, an inverse transfer function is formulated. Validity of the proposed control methods was verified with numerical simulations and experiments. The results show good control performance without disturbance. Feedforward control based on the low-pass inverse system worked quite effectively without disturbance. When subjected to …external disturbance, the feedback control performance remains quite good. Show more

Keywords: IPMC actuator, feed forward control, inverse system, feedback control, robustness

DOI: 10.3233/JAE-2010-1197

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 875-881, 2010

Authors: Pei, Yongmao | Fang, Daining

Article Type: Research Article

Abstract: A magnetoelastic constitutive theory of nonlinear anhysteretic behaviors based on domain rotation is presented in this paper for giant magnetostrictive materials (GMMs). For a Tb-Dy-Fe polycrystal with preferred orientations, the magnetic moments of domains are constrained by the anisotropy to lie along the <111> easy magnetization directions. Thus, the fractional occupancies of only the eight <111> directions and the field direction are calculated using an inverse exponential distribution function for …simplicity. The linear fitting of the potential distribution parameter with the pre-stress is obtained from the magnetization curves under different compressive stresses for a [110] oriented Tb-Dy-Fe rod, which is used to predict the magnetostriction behaviors. It shows good quantitative agreement with the experimental results under a range of constant uniaxial compressive stresses. Show more

DOI: 10.3233/JAE-2010-1198

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 883-889, 2010

Authors: Saito, Takeshi

Article Type: Research Article

Abstract: The belief for many years has been that magnetic materials should be arranged without any space between them to achieve a sufficient magnetic shielding effect. However, it was determined that a wall made by aligned strips with sizable gaps could achieve almost the same magnetic shielding effect as a wall using the conventional continuous plate method. In this paper, the new method using aligned strips with gaps is called the open-type magnetic shielding method. The open-type …magnetic shielding method allows light and air to pass through walls/boxes providing opportunities to improve a wide range of applications. This study reports the process to devise this open-type magnetic shielding method with some experimental data. Show more

Keywords: Magnetic fields, magnetic shielding, shielding, silicon steel

DOI: 10.3233/JAE-2010-1199

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 891-899, 2010

Authors: Cheng, Wei | Zhang, Jianhui | Hu, Xiaoqi | Xia, Qixiao

Article Type: Research Article

Abstract: Traditional valveless piezoelectric pumps are difficult to be minimized for its special tubes installed outside the chamber. Moreover, the effect of mixing different kinds of liquid is not good. In order to improve the configuration and performance of the pump, a novel valveless piezoelectric pump – valveless piezoelectric pump with unsymmetrical slopes elements (USE) is developed. It is designed aimed at intensing the vortex field in the chamber during pumping. The intense vortex field is helpful …to stir and mix different liquids in the chamber to produce solution, homogeneous emulsion or turbid liquid. Firstly, pumping principle of the proposed pump is analyzed. Then, numerical models are established, and simulation and numerical calculation on the flow fields in the chambers are carried out.Finally, experiments are implemented to verify the validity and reliability of numerical analysis. Show more

Keywords: Piezoelectricity, valveless, pump, flow field, unsymmetric slopes element

DOI: 10.3233/JAE-2010-1200

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 901-909, 2010

Authors: Murakami, Takahiro | Sakai, Michiya | Nakano, Masami

Article Type: Research Article

Abstract: The characteristics of a passive type MR damper were evaluated experimentally. The damper has variable damping characteristics as well as an existing semi-active damper, although it is fully passive device without any sensor, power supply and power controller. A prototype of the damper was manufactured in order to verify the damping and response characteristics. The excitation tests with sinusoidal displacement demonstrate that the damping force changes in response to the sign of the product of the …velocity and displacement, which is analogous to one of semi-active control. The base excitation tests with a single-degree-of-freedom system show that the passive type MR damper has excellent damping effect in a wide range of frequency. In particular, the advantage is noticeable at resonance frequency. It is also shown that the base isolation system with the present damper is quite effective in a reduction of the response to earthquake excitation. Show more

Keywords: Magnetorheological fluid, MR damper, Excitation test, Damping characteristics, Response characteristics

DOI: 10.3233/JAE-2010-1201

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 911-917, 2010

Authors: Sun, Yanhua | Kang, Yihua

Article Type: Research Article

Abstract: For the drawbacks of present MFL (magnetic flux leakage) testing of omni-directional defects using multidirectional magnetization, a new method of MFL inspection for omni-direction defects under a unidirectional magnetization is proposed. Then, its feasibility is verified by simulations and experiments, leading to a breakthrough of the conventional MFL theory which argues that there is little MFL produced by the defects parallel or nearly parallel to the magnetization direction. Additionally, a method for ensuring a uniform …evaluation for the defects with same sizes but different directions is also presented. Finally, some good application cases of the proposed technology were shown. Show more

Keywords: MFL (magnetic flux leakage), Unidirectional magnetization, Axial magnetization, Omni-directional defects

DOI: 10.3233/JAE-2010-1202

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 919-925, 2010

Authors: Zhang, Hongyan | Bai, Changqing | Li, Yueming

Article Type: Research Article

Abstract: The static and dynamic responses analysis for the 1–3 piezocomposite laminates equipped with Interdigitated Electrodes (IDE) is performed with analytical method. In the static analysis, the solution of the derived governing differential equations is obtained through the power series expansion and Fourier expansion methods. In the dynamic analysis, the governing equations for the transverse vibration are established based on the thin plate theory, and the solutions are obtained through the separation of variables and …Fourier expansion methods. The illustrative analysis is carried out to investigate the static and dynamic characteristics of the laminated plates. The numerical results show that, the magnitude of shear curvature gradually increases with the increment of the stiffness anisotropy and the free-strain anisotropy of the piezocomposite and the vibration suppression can be also achieved by adopting a time-dependent control voltage to the IDE of the piezocomposite. Show more

Keywords: 1–3 piezocomposite, static and dynamic responses, Analytical method, The Interdigitated electrode

DOI: 10.3233/JAE-2010-1203

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 927-934, 2010

Authors: Takeno, Takanori | Ohno, Takeshi | Miki, Hiroyuki | Takagi, Toshiyuki

Article Type: Research Article

Abstract: Electrical conductive properties of copper-carbon composite coatings were investigated. Films of several hundred nanometers were deposited onto dielectric substrates using acetylene-generated plasma and co-sputtering of copper target. Transmission electron microscope was employed for the analyses of the microstructure of the coatings. Temperature dependence of resistance of the investigated coatings was measured by changing the temperature from 80&ndash;400 K in vacuum condition. Electrical conductive properties were discussed in terms of the microstructure of …the coatings deposited under the various conditions. Show more

Keywords: copper, amorphous carbon, nano-particle, electrical conductive properties

DOI: 10.3233/JAE-2010-1204

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 935-940, 2010

Authors: Liu, Dandan | Zhao, Can | Li, Huajun | Tang, Chunrui

Article Type: Research Article

Abstract: Based on application actuality for colliery hydraulic support directional valve, we put forward a magneto-rheological (MR) driving based directional valve. Firstly, accounting of the MR driving mechanism, the frame model of the electro-hydraulic directional control valve is established based on MR fluid, and the feasibility of this new directional valve is expatiated based on the MR driving. Secondly, a mathematical model of the MR valve is established for the numerical simulation. Finally, the computational fluid …dynamics (CFD) technique is adopted for the numerical simulation of the inner flow field of the directional valve to obtain the pressure, velocity, and other parameters. Comparing the new directional valve with the traditional one, it has features of simple structure, less moving parts, fast motion response, and high dependability. Show more

Keywords: Hydraulic support, magneto-rheological, numerical simulation, directional valve

DOI: 10.3233/JAE-2010-1205

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 33, no. 3-4, pp. 941-946, 2010