International Journal of Applied Electromagnetics and Mechanics - Volume 14, issue 1-4

Authors: Komagome, Yuji | Matsumoto, Eiji

Article Type: Research Article

Abstract: The surface strain distribution of a plate can be measured from the electric potential on the piezoelectric film mounted on it. When the plate with a back surface defect is deformed, the resultant strain distribution on the front surface reflects the size and the shape of the defect. Instead of measuring the electric potential by the electrostatic voltmeter, this paper attempts to visualize the strain distribution by means of absorption of charged polymer powder to the …piezoelectric film. And also attempting this method to the various size of the defect, resolution of detecting the defects is discussed by the experiment. Show more

DOI: 10.3233/JAE-2002-418

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 425-428, 2002

Authors: Nowacki, J.P. | Alshits, V.I. | Radowicz, A.

Article Type: Research Article

Abstract: The 2D electro-elastic fields in the piezoelectric layer-substrate structure with the general line defect are found. The considered line source consists of the four coinciding straight sources: the line of forces, the charged line, the dislocation line and its electrostatic analogue. Electrically, the surface of the layer is supposed to be either metallized or adjoined to an isotropic dielectric medium. Mechanically, two boundary problems are also considered: the surface is free, and the surface is clamped. …The solutions obtained for a general case of unrestricted anisotropy are presented in a form of convergent Fourier integrals. The integrands are implicitly expressed in terms of the eigenvalues and the eigenvectors of the generalized Stroh matrix. Their finding needs additional computing. Show more

DOI: 10.3233/JAE-2002-416

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 429-433, 2002

Authors: Wakiwaka, Hiroyuki | Yamada, Yoji | Watanabe, Toshihiko | Umemoto, Yoshiyuki | Kiyomiya, Teruo | Makimura, Mika

Article Type: Research Article

Abstract: Giant magnetostrictive thin films are suitable to develop new micro-sensors and micro-actuators due to their superior characteristics. In this paper, the influence on magnetostriction characteristic of magnetron sputtered film by sputtering condition is described. The thin film shows large magnetostriction in Tb composition 40 at %, in anneal temperature 300°C.

DOI: 10.3233/JAE-2002-419

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 435-438, 2002

Authors: Tufescu, Florin Mihai | Chiriac, Horia | Óvári, Tibor-Adrian | Stancu, Alexandru

Article Type: Research Article

Abstract: Results on the FMR investigation of the effect of applied tensile stresses on the surface magnetic anisotropy of Co6_{8.25} Fe_{4.5} Si_{12.25} B_{15} amorphous glass-covered wires are reported. Axially applied stresses lead to a decrease of the resonance field and absorption intensity that correspond to the main resonance peak, indicating a reinforcement of the circumferential magnetoelastic anisotropy from the wire's surface region. The FMR spectra determined at 8.5 GHz …-- the lowest employed frequency of the microwave field -- display a compound aspect, i.e. a secondary resonance peak is observed at slightly larger values of the dc magnetic field. This fact indicates that one can detect a region with different anisotropy direction towards the wire's inner zone when the magnetic penetration depth is large enough. The obtained results are valuable as regards the sensor applications of such materials. Show more

DOI: 10.3233/JAE-2002-420

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 439-442, 2002

Authors: Tachibana, Toshihide | Kikura, Hiroshige | Matsuzaki, Mitsuo | Yamanaka, Gentaro | Aritomi, Masanori | Kobayashi, Yuji | Nakatani, Isao

Article Type: Research Article

Abstract: Thermal behavior and cluster formation of ferromagnetic particles in the water-based, kerosene-based and alkyl-naphthalene-based magnetic fluids were investigated using an optical microscope system. Real-time visualization of the Brownian motion and the chain-like cluster formation of three types of particles were carried out under a magnetic field. The influence of the magnetic field intensity and the temperature variation on cluster formation of ferromagnetic particles was investigated.

DOI: 10.3233/JAE-2002-422

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 443-446, 2002

Authors: Yamane, Ryuichiro | Togashi, Kazuo | Chinone, Yasuhiro | Park, Myeong-Kwan

Article Type: Research Article

Abstract: Method to induce and control the flow of the magnetic fluid using a double-decked linear motor is proposed and tested. The upper coil of the linear motor generates the basic traveling magnetic field, and the lower one the second harmonics. When the electric current is supplied to only one of the upper and the lower coils, the induced velocity of the magnetic fluid increases with the increase in the strength and the frequency of the applied electric …current. When applied simultaneously to the same or opposite direction, the induced velocity is approximated by the square root of the sum or the difference of the square of each velocity at independently applied electric current, respectively. Show more

DOI: 10.3233/JAE-2002-499

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 447-450, 2002

Authors: Sudo, S. | Ise, K. | Nishiyama, H. | Tani, J.

Article Type: Research Article

Abstract: The results of an experimental study of frequency characteristics of a permanent magnet-magnetic fluid element on a vertically vibrated table were presented and discussed in some detail. Some effects of excitation frequency on the motion of the magnet-magnetic fluid element were noted. The dynamic behavior of magnetic fluid surface was also revealed by two high speed digital cameras.

DOI: 10.3233/JAE-2002-414

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 451-454, 2002

Authors: Shimada, Kunio | Syuchi, Narimitsu | Kamiyama, Shinichi | Yamaguchi, Hiroshi

Article Type: Research Article

Abstract: Numerical analysis of a steady magnetic fluid flow in a straight pipe is made by taking into account nonuniform distribution of mass concentration and formation of prorate spheroids of magnetic particles under a steady nonuniform magnetic field. The local shear rate, number of aggregated particles as a prorate spheroid and fluid velocity distribution are obtained to be clarify that their large change exists at the down stream area of the magnetic field. The relation of wall …friction to Reynolds number shows good agreement with the experimental data. Show more

DOI: 10.3233/JAE-2002-417

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 455-458, 2002

Authors: Li, B.Q. | He, R.

Article Type: Research Article

Abstract: This paper discusses the numerical modeling of coupled electromagnetic and transport (fluid flow and heat and mass transfer) phenomena in materials processing systems under both terrestrial and microgravity conditions. Two types of magnetically induced transport phenomena are considered and both require iterative numerical computations. For the former, the flow is activated through Faraday's law and the computational methodology entails the use of the boundary element method to model the free space region …and of the finite element method to model the interior region of the liquid. Computations involve the iterative solution of magnetic fields, fluid flow and surface stress balance when free surface deformation occurs. For the later, the fluid motion is suppressed by an applied DC magnetic field and flow and magnetic fields are coupled so that iterative computational procedure is again required. For this later case, computational costs are substantially reduced by carefully designing the finite element global matrix structure. Show more

DOI: 10.3233/JAE-2002-500

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 459-466, 2002

Authors: Shoji, Tetsuo | Sato, Yasumoto | Minkov, Dorian | Yagi, Kenichi | Baba, Toshimitsu | Tamakawa, Kinji

Article Type: Research Article

Abstract: The objective of the Center of Excellence (COE) program is to provide a fundamental understanding of the physics and chemistry of fracture under combined environments and to apply this understanding to establish structural life prediction and control systems for high quality human safety. With this aim, we have developed analytical methods for the local measurement of materials chemistry, crack tip water chemistry, crack tip strain and defects. We summarize the research activity of COE program and …some recent progress using the electromagnetic NDE technique will be reviewed. Show more

DOI: 10.3233/JAE-2002-521

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 14, no. 1-4, pp. 467-476, 2002