International Journal of Applied Electromagnetics and Mechanics - Volume 24, issue 1-2

Authors: Agneni, Alessandro | Del Sorbo, Matteo | Mastroddi, Franco | Polli, Gian Mario

Article Type: Research Article

Abstract: Piezoelectric devices shunted on resistive-inductive loads typically operates on a single mode of a structure as their mechanical counterparts: the vibration absorbers. Similarly, multiple piezo patches, operating on different vibrating modes, may be used to perform a multi-modal damping. This result may be achieved either connecting different piezo patches to different electrical circuits, either connecting to a single multiple mode network one single set of piezo-electric elements. Several ladder networks were proposed in the past in …order to damp more modes simultaneously. In this paper a Cauer network has been adopted together with notch filters having the duty to filter out one mode at a time. The possibility to use this type of circuit has been investigated studying the elastic and aeroelastic vibrations of a small glider wing by means the aeroelastic analysis performed by a commercial code based on a modal approach. Show more

DOI: 10.3233/JAE-2006-709

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 1-24, 2006

Authors: Jiang, S.N. | Jiang, Q. | Hu, Y.T. | Li, X.F. | Guo, S.H. | Yang, J.S.

Article Type: Research Article

Abstract: We study mechanical-to-electrical power conversion in a piezoelectric ceramic shell mechanically forced into thickness-shear vibrations. A theoretical analysis is performed. The efficiency of energy conversion, the power density of the device and their dependence on various physical and geometric parameters are examined. The structure may be used as an electric power source for wireless devices.

DOI: 10.3233/JAE-2006-708

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 25-31, 2006

Authors: Wang, B.L. | Han, J.C. | Mai, Y.W.

Article Type: Research Article

Abstract: In this paper, we developed a closed-form solution for anti-plane mechanical and in plane electric and magnetic fields in a magnetoelectroelastic layer of finite thickness. Explicit expressions for the stresses, electric fields, and magnetic field, together with their intensity factors and the energy release rate are obtained for the extreme cases of impermeable and permeable crack assumptions, including electrically impermeable and magnetically permeable crack assumption, electrically permeable and magnetically impermeable crack assumption, …fully impermeable crack assumption, and fully permeable crack assumption. It is shown that the crack face electromagnetic boundary conditions have strong influence on the crack tip electromagnetic field intensity factors and energy release rate. The stress intensity factor, however, does not depend on the crack electromagnetic boundary condition assumptions. Using the basic solution for the single crack problem, solutions for the problems of two collinear cracks, a periodic array of parallel cracks, and two periodic arrays of parallel cracks are also given. Show more

Keywords: Magnetoelectroelastic materials, fracture mechanics, cracks

DOI: 10.3233/JAE-2006-710

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 33-44, 2006

Authors: Ho, Mingtsu

Article Type: Research Article

Abstract: One-dimensional numerical results of the induced currents on traveling and/or vibrating perfect conductor surfaces are presented in this report. The computational data are obtained using the method of characteristics with the application of the characteristic variable boundary conditions and the relativistic boundary conditions. The perfect plane may travel at a constant speed and/or vibrate sinusoidally or in zigzag with a constant frequency and a constant amplitude. The Doppler effects on both magnitude and frequency of …induced currents were investigated by comparing computational results with the theoretical double-Doppler shift values. Good agreements were found. It is also found that when conductor travels and vibrates simultaneously, modulation on the magnitude of induced current is dependent on the combined instantaneous velocity while that on frequency is on the translational velocity. Show more

DOI: 10.3233/JAE-2006-707

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 45-50, 2006

Authors: Zhou, Shu-Ang | Uesaka, Mitsuru

Article Type: Research Article

Abstract: This article introduces a theory of studying transport phenomena of charged or polarizable nano-particles in some biological media in electromagnetic fields. The mathematical formulation of the transport phenomena given in the article is based on systematic usage of non-equilibrium thermodynamics and continuum electrodynamics for thermodynamic open systems. Some complete sets of fundamental equations for the analyses of the transport phenomena fulfilling basic physical laws are derived in the article. Possible effects of …viscosity, viscoelasticity, heat and mass flow, electric diffusion current and polarization in either fluid or solid-like mixtures are characterized properly in our theoretical model, including their coupling effects. The theory may be used not only for analyzing transport phenomena of some nano-drug carriers in drug delivery systems, but also for studying molecular transport problems in some engineering applications. The formulated theory is generally nonlinear, which may however be linearized in some cases. Illustratively, a coupled electrodiffusion wave problem is analyzed with a linearized model and its solution is discussed with some possible applications outlined. Show more

Keywords: Diffusion wave, drug delivery, electrodynamics, nano-particles, polarization

DOI: 10.3233/JAE-2006-781

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 51-67, 2006

Authors: Kharytonov, Alexander

Article Type: Research Article

Abstract: The solution of inverse boundary problems are considered. One must determine the coefficients or functions of elliptic differential equations inside the domain Ω from a knowledge of boundary conditions (the Cauchy data) on the boundary ∂Ω. The algorithms for the numerical solution of such problems are presented.

Keywords: Inverse problem, parameter identification, Green's function, Lippmann-Schwinger equation

DOI: 10.3233/JAE-2006-777

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 69-77, 2006

Authors: Arunachalam, Kavitha | Udpa, Satish S. | Udpa, Lalita

Article Type: Research Article

Abstract: Non-intrusive inspection (NII) systems with high throughput are required for screening baggage, vehicles and cargo at ports of entry. Of the existing NII techniques, systems employing X-rays have undergone rapid evolution. Though well established, the probability of detecting contraband goods in the radiographic image obtained using conventional high energy X-ray systems depends on operator skill and orientation of the contraband material inside the container. Alternative techniques employing back and forward scattered X-rays …operating at dual energy can only broadly classify objects containing contraband material and cannot be used to uniquely locate the contraband good. Limitations of X-ray radiography and scattererd imaging systems could be resolved using 2D tomography systems. But, the complexities associated with practical implementation of an X-ray CT system for screening baggage, vehicles and cargo is far from realization. This paper presents an X-ray imaging technique capable of providing 2D tomograms using limited-view projections as an ideal compromise for detecting packaged, vehicle-borne and human-borne explosives, weapons and contraband goods. Numerical simulations of the proposed system employing L-shaped detectors and iterative reconstruction algorithms indicate the feasibility of an alternate security screening system to detect and uniquely locate explosives and contraband goods concealed in cargo, baggage and vehicles. Show more

Keywords: Security screening, X-rays, limited view, tomography

DOI: 10.3233/JAE-2006-778

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 79-89, 2006

Authors: Venkov, George

Article Type: Research Article

Abstract: The paper investigates the propagation of a plane electromagnetic wave in the exterior of a perfectly conducting torus. Using the fact that in toroidal coordinates the vector Helmholtz equation does not admit separation of variables we apply the low-frequency method and the electromagnetic scattering problem reduces to a sequence of potential problems. The incomplete R-separation leads to infinite system of three-diagonal form. More precisely, the boundary conditions for the magnetic field produce a third-order recurrence …relations, due to the Riemannian radical and the non-orthogonality of the toroidal harmonics in the angular variable. The three-diagonal infinite systems of linear algebraic equations are solved analytically via the appropriate use of finite continuous fractions. Show more

Keywords: Electromagnetic scattering, low-frequency approximation method, toroidal harmonics, infinite algebraic systems; The author is partially supported by the NATO–CNR Advanced fellowships no. 215.36 S

DOI: 10.3233/JAE-2006-779

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 91-103, 2006

Authors: Chien, Wei | Huang, Chung-Hsin | Chiu, Chien-Ching

Article Type: Research Article

Abstract: This paper presents a computational approach to the imaging of a two-dimensional periodic conductor. Both cubic-spline method and trigonometric series for shape description are used and compared. A periodic conducting cylinder with unknown shape in free space and the scattered field is recorded outside. Based on the boundary condition and the recorded scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. The genetic algorithm is …employed to find out the global extreme solution of the object function. It is found that the shape described by cubic-spline can be reconstructed. In such a case, Fourier series expansion will fail. Even when the initial guess is far away from the exact one, the cubic-spline expansion and genetic algorithm can avoid the local extreme and converge to a global extreme solution. Numerical results are given to show that the shape description by using cubic-spline method is much better than that by the Fourier series. In addition, the effect of Gaussian noise on the reconstruction is investigated. Show more

DOI: 10.3233/JAE-2006-780

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 105-114, 2006

Authors: Jeong, K.M. | Beom, H.G.

Article Type: Research Article

Abstract: Cracking near the edge of an internal electrode embedded in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. Under small-scale conditions, the stress intensity factor induced by ferroelectric domain switching is numerically obtained for dissimilar crack surface boundary conditions: the insulating crack and the conducting crack. It is found that the …stress intensity factor for a crack emanating from an internal electrode depends strongly on the ratio of the coercive electric field to the yield electric field. Show more

Keywords: Cracking, ferroelectric ceramics, domain switching, electrical nonlinearity

DOI: 10.3233/JAE-2006-884

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 24, no. 1-2, pp. 115-127, 2006