International Journal of Applied Electromagnetics and Mechanics - Volume 27, issue 1-2

Authors: Lefebvre, J.H.V. | Mandache, C.

Article Type: Research Article

Abstract: The focus of this study is the behaviour of the lift-off point of intersection (LOI) under various test conditions: lift-off, thickness and conductivity of metallic layers with and without a ferromagnetic substrate. The pulsed eddy current (PEC) signal response is analyzed and a lift-off independent method to measure the thickness of conductive layers over ferromagnetic substrates is presented. This approach is tested by scanning specimens with varying lift-off and conductive layer thickness. The test …articles have different substrate permeabilities, but identical lift-off and conductive layer conditions. The results demonstrate that the LOI feature can be used to measure the thickness of conductive layers over ferromagnetic substrates. Show more

Keywords: Pulsed eddy current (PEC), lift-off point of intersection (LOI), ferromagnetic substrate

DOI: 10.3233/JAE-2008-922

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 1-8, 2008

Authors: Yang, Fuqian | Song, Wei

Article Type: Research Article

Abstract: The surface evolution of an elastic conducting cylinder carrying electric current was analyzed by considering the effect of magnetomechanical interaction and using the linear perturbation analysis. The driving force controlling the surface growth was the gradient of the chemical potential, consisting of the contributions of elastic energy, electromagnetic energy and surface energy. A general expression of the dispersion relation was obtained for describing the morphological evolution of the conducting cylinder subjected to …self-induced magnetic field. It was found that the magnetomechanical interaction can enhance or inhibit the morphological instability of the elastic conducting cylinder when subjected to a far-field tensile stress. Such analysis might be of importance in understanding the surface evolution of nano-rods and nano-wires when carrying electric current. Show more

DOI: 10.3233/JAE-2008-937

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 9-24, 2008

Authors: Hou, Peng-Fei | Luo, Wei | Leung, Andrew Y.T.

Article Type: Research Article

Abstract: We use the compact mono-harmonic general solutions of transversely isotropic magneto-electro-thermo-elastic materials to construct the three-dimensional solutions of a steady point heat source on the apex of a transversely isotropic magneto-electro-thermo-elastic cone by five newly introduced mono-harmonic functions. All components of coupled field are expressed in terms of elementary functions and are convenient to use. When the apex angle 2α equals to π, the solutions reduce to those of the semi-infinite body …problem. Numerical results are given graphically by contours. Show more

Keywords: Point heat source, transversely isotropic, magneto-electro-thermo-elastic, cone

DOI: 10.3233/JAE-2008-936

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 25-41, 2008

Authors: Yatchev, Ivan | Hinov, Krastyo | Trifonov, Nikola

Article Type: Research Article

Abstract: Modelling and characteristics of a newly developed bistable permanent magnet linear actuator are presented. The permanent magnets are fixed and the mover is soft magnetic one. The driving and the holding force can be varied practically independently as they are mainly formed through different air gaps. Static and dynamic characteristics of the actuator are obtained. The static force characteristics are obtained using finite element method for different permanent magnets, different combinations of the two air gaps …and different coil currents. Dynamic characteristics are obtained for actuator with ferrite magnets. The results for static and dynamic characteristics are verified experimentally on a prototype of the actuator with ferrite magnets. Show more

Keywords: Linear actuators, permanent magnets, force-stroke characteristics, dynamic characteristics

DOI: 10.3233/JAE-2008-934

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 43-52, 2008

Authors: Tian, W. | Rajapakse, R.K.N.D.

Article Type: Research Article

Abstract: A mathematical model is presented to determine the fracture parameters of a finite impermeable crack with one or more branches in a magnetoelectroelastic plane subjected to the remote mechanical, electrical and magnetic loading. An integral equation approach based on the fundamental solution for a generalized dislocation is used to formulate the problem. The problem is reduced to a set of singular integral equations with the dislocation densities along the crack line as the unknown variables. The …integral equation system is solved by using numerical quadrature. Selected numerical results are presented to demonstrate the dependence of crack tip field intensity factors on branch length, branch orientation, poling orientation of the medium and type of loading. Numerical results imply that a branch crack cannot propagate in a self-similar manner. Solutions for a crack with double branches show that simultaneous propagation of branches is not possible. Show more

Keywords: Branched crack, fracture mechanics, impermeable crack, magnetoelectroelastic materials, piezoelectricity, stress intensity factors

DOI: 10.3233/JAE-2008-932

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 53-74, 2008

Authors: Nagaya, Kosuke | Kojima, Takako | Hosoya, Syunsuke | Eda, Keiichi | Ando, Yoshinori | Ge, De-Liang

Article Type: Research Article

Abstract: A self-washing toilet system suitable for patient care is presented. The system consists of rubber pants that are worn by the patient and sealed by inflation with air. Excrement is flushed from the toilet with water via an outlet tube, and the system is flushed with air to dryness. Control systems are developed for the detection of humidity and urine, and for maintenance of appropriate inflation pressures. The inflation system effectively seals around the thighs and …waist without discomfort, and reliably differentiates between natural moisture and urine. The underwear type toilet and control system are constructed and demonstrated experimentally to be applicable, in principle, for practical use. Show more

Keywords: Care, toilet, pants, control, self-washing

DOI: 10.3233/JAE-2008-931

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 75-91, 2008

Authors: Senjuntichai, T. | Kaewjuea, W. | Rajapakse, R.K.N.D.

Article Type: Research Article

Abstract: This paper considers quasi-static linear response of a solid piezoelectric cylinder due to electric voltage and mechanical loading applied at the ends. A recently developed analytical general solution for an annular cylinder of finite length is used to analyze this complex mixed-boundary value problem. The general solution for electroelastic field and the applied loading are expressed in terms of Fourier-Bessel infinite series. Both flexible electrodes in smooth contact with and rigid electrodes bonded to the cylinder …ends are considered. The problem is formulated by dividing the electrode contact area into several annular rings and developing a flexibility equation system based on a set of influence functions to satisfy the mixed-boundary conditions at the cylinder ends. The present approach allows consideration of a cylinder under a variety of electromechanical loading conditions. Accuracy of the present scheme is confirmed by comparing with the existing solutions for the limiting case of an elastic cylinder. Selected numerical results for different cylinder length-radius ratios, electrode dimensions, materials and electric voltage and mechanical loads are presented to demonstrate the coupled electromechanical behavior of a cylinder. Show more

Keywords: Actuators, cylinders, elasticity, piezoelectricity, stress analysis

DOI: 10.3233/JAE-2008-923

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 93-116, 2008

Authors: Zhou, Zhen-Gong | Wang, Biao

Article Type: Research Article

Abstract: In this paper, the dynamic behavior of an interface crack between two dissimilar functionally graded piezoelectric/piezomagnetic material half infinite planes subjected to the harmonic anti-plane shear stress waves is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with coordinate vertical to the crack. By using the Fourier transform technique, the problem can be solved with the help of a pair of dual integral equations in which the unknown variable …is the jump of displacements across the crack surfaces. These equations are solved by using the Schmidt method. The relations among the electric filed, the magnetic flux field and the dynamic stress field near the crack tips can be obtained. Numerical examples are provided to show the effect of the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack. Show more

Keywords: Functionally graded piezoelectric/piezomagnetic materials, crack, stress wave

DOI: 10.3233/JAE-2008-921

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 117-132, 2008

Authors: Lin, Chin E. | Ker, C.C.

Article Type: Research Article

Abstract: A ball and plate system is constructed using magnetic suspension actuators on two axes for three degrees of freedom control. System characteristic in mathematical model for control is formulated using the backstepping control theory. According to the backstepping control design procedure, the proposed controller is fabricated on a single-chip microprocessor as control kernel and tested with supporting electronic circuits. Several scenarios of dynamic operation such as oscillatory stabilization and circular trajectory tracking …are tested to verify the proposed system performance and capability. Show more

Keywords: Ball and plate system, backstepping control, magnetic suspension actuator, trajectory tracking

DOI: 10.3233/JAE-2008-933

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 133-151, 2008

Authors: Turetken, Bahattin | Ustuner, Fatih | Demirel, Ekrem | Baran, Ersan

Article Type: Research Article

Abstract: In this paper, the coupling analysis of HF antennas mounted on a ship is presented. The method of Moments (MoM) is used to calculate the inter antenna coupling in 1.6–30 MHz frequency range. Numerical results with MoM are performed and the reliability of these methods is discussed according to the measurement results. The coupling measurements were acquired on 1:50 scale model of the shipboard.

DOI: 10.3233/JAE-2008-935

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 27, no. 1-2, pp. 153-159, 2008