Thermomagnetic optimization of solenoidal magnetostrictive actuators

Abstract

Magnetostrictive materials often rely on magnetic fields generated through the use of a solenoidal coil. However, the field-generating coil also acts as a source of heat causing thermally induced strains in the magnetostrictive drive element. To insure that the useful magnetostrictive strains are large in comparison with the thermally induced strains, the solenoid may be optimized. This paper presents a simple one dimensional (1-D) magnetic model useful for predicting the magnetic field inside the magnetostrictive drive rod. The advantage of this model is that it can be evaluated very quickly, making it well suited for use in optimization algorithms. A figure of merit is presented that weighs the energy stored in the coil against the power that must be dissipated to maintain the field. With the magnetic model and cost function, the solenoid may be sized to maximize the volume averaged field in the magnetostrictive element per unit of volume averaged dissipated heat in the solenoidal coil. While previous work addressed field/power optimization at the center of air-cored solenoids, the work presented here considers optimization of the average field along a rod of permeable magnetostrictive material. The results indicate that coil quality decreases rapidly if the coil is thinner than optimal, but decreases rather slowly for a thicker than optimal coil.

Exact solution for 2D polygonal inclusion problem in anisotropic magnetoelectroelastic full-, half-, and bimaterial-planes

“…It is particularly interesting that although magnetoelectric coupling does not exist in piezoelectric or piezomagnetic phase alone, it can be acquired in the corresponding composites, and the effect could be even larger than that in some of the single phase materials of magnetoelectricity (e.g., Nan, 1994). The energy conversion among elastic, electric, and magnetic forms provides numerous opportunities for potential applications of the coupling materials and structures as ultrasonic transducers, magnetic-field probes, and microdrives (Erber et al, 1997;Gibbs et al, 1997;Frank and Schilling, 1998;Meeker and Dozor, 1999;Li, 2003). In order to understand the coupling features in and among PE, PM, and ME, various analytical and numerical studies have been also carried out (Daher, 1996;Ting, 1996;Huang and Kuo, 1997;Li and Dunn, 1998;Aboudi, 2000;Li, 2000Li, , 2003Liu et al, 2001;Pan, 2001Pan, , 2002aPan and Heyliger, 2002;Chen and Lee, 2003;Ding and Jiang, 2003;Gao et al, 2003a,b;Horiguchi and Shindo, 2003;Soh et al, 2003;Wang and Zhong, 2003a,b;Pan and Han, submitted for publication).…”

“…Many striking features have been observed as related to the coupling among the elastic, electric, and magnetic fields, such as piezoelectric (PE), piezomagnetic (PM), magnetoelectric (ME) and magnetoelectroelastic couplings (Benveniste, 1995;Erber et al, 1997;Meeker and Dozor, 1999;Sander, 1999;Aboudi, 2001;Fiebig et al, 2002;Ryu et al, 2002;Mazumder and Battacharyya, 2003). It is particularly interesting that although magnetoelectric coupling does not exist in piezoelectric or piezomagnetic phase alone, it can be acquired in the corresponding composites, and the effect could be even larger than that in some of the single phase materials of magnetoelectricity (e.g., Nan, 1994).…”