International Journal of Applied Electromagnetics and Mechanics - Volume 10, issue 5

Authors: Di Barba, P. | Savini, A.

Article Type: Research Article

Abstract: A new benchmark for inverse problems in magnetostatics is proposed; it deals with the optimal design of the pole profile of an iron-cored H-shaped electromagnet. The objective function, expressing the field uniformity in the air gap, is computed via the finite element method. The inverse problem is solved by synthetizing the distribution of the magnetic material in the design region; the optimization procedure relies on a stochastic method.

DOI: 10.3233/JAE-1999-148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 371-379, 1999

Authors: Chattopadhyay, Manidipa | Chakraborty, S.K. | Chakraborty, Sarbani

Article Type: Research Article

Abstract: The existence of Love-type SH waves in an electrically finitely conducting elastic half-space under the action of a uniform magnetic field has been studied. Damped magneto-elastic SH waves are found to exist under a high magnetic field acting in the direction of propagation of the wave.

DOI: 10.3233/JAE-1999-153

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 381-389, 1999

Authors: Agbossou, Amen | Nguyen Viet, Hung | Pastor, Joseph

Article Type: Research Article

Abstract: Investigating piezoelectric composites is a recent research domain. Direct measurements on piezoelectric composites are not always easy, making the use of homogenization to determine all its electroelastic characteristics of major interest. This work presents the homogenization for the periodic piezoelectric media by means of the finite element method. The particular details are given for generalized plane strain (GPS) case. As application of the proposed model, numerical developments were presented for three different piezoelectric media: unidirectional piezoelectric fiber composites, 1.3 piezoelectric transducer and muscle materials considered as “semi-piezoelectric” material. The predicted values are in good agreement with the other numerical results …in literature and the available experimental data. Show more

DOI: 10.3233/JAE-1999-154

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 391-403, 1999

Authors: Gusev, Evgeny L.

Article Type: Research Article

Abstract: The problem of the optimal synthesis of inhomogeneous structures of a discrete set of materials under wave influence is considered. It is established that in the interdependence between parameters of structures that realize the limiting possibilities some order or inner symmetry may exist under certain conditions. This fact allows to solve the problem of synthesis of layer structures in a straightforward way.

DOI: 10.3233/JAE-1999-156

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 405-416, 1999

Authors: Borghi, C.A. | Fabbri, M. | Di Barba, P. | Savini, A.

Article Type: Research Article

Abstract: The optimal shape design of Loney’s solenoid is carried out by different techniques of global optimization. The underlying inverse problem, which is numerically ill-conditioned with a gorge behavior, shows an outstanding potential as benchmark for magnetostatic inverse problems. In the paper four minimization methods have been compared: two of them are deterministic (Simplex and Quasi-Newton methods), two are stochastic (Evolution Strategy (1+1) formulation and Filled Function method combined with the Evolution Strategy method). The results have been discussed and compared.

DOI: 10.3233/JAE-1999-158

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 417-423, 1999

Authors: Chou, Chan-Shin | Chang, Chia-Ou | Hwang, Jeng-Jye

Article Type: Research Article

Abstract: In this paper the stability and precession phenomenon of the modal pattern of a rotating hemispherical shell gyro excited parametrically by electrostatic forces is investigated. Nonlinear modal equations of the rotating shell under small strain and moderate rotation are derived by following Niordson’s thin shell theory. The method of multiple time scales is used to determine quantitatively the vibration displacement of the shell from which the precession rate of the modal vibration pattern can be extracted. Floquet theory is employed to study the stability of the analytical solution. Numerical simulation verifies the analytical results.

Keywords: Hemispherical resonator gyro, electrostatic excitation, stability

DOI: 10.3233/JAE-1999-159

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 10, no. 5, pp. 425-449, 1999