J. Eng. Technol. Educ. (2013) 10(2): 221-228 June 2013 Journal of Engineering Technology and Education, ISSN 1813-3851 Damping Characteristics Analysis of Rectangular Plate with Magnetorheological Elastomer Core Treatments Jia-Yi Yeh* Department of Information Management, Chung Hwa University of Medical Technology, Tainan, Taiwan *E-mail: yeh@mail.hwai.edu.tw Abstract The damping characteristics analysis of rectangular plate with magnetorheological (MR) elastomer core treatment is studied in this investigation. The rectangular plate is subjected with a magnetorheological elastomer core layer to improve and control the damping behaviors of the sandwich rectangular plate system. The MR elastomer shows variations in the rheological properties when subjected with varying magnetic fields. Besides, MR material exhibits rapid time response and is applicable to the structures or devices. The MR elastomer is found to have a significant effect on damping characteristics of the sandwich rectangular plate. The modal dampers for the sandwich rectangular plate system are calculated for various magnetic fields. The damping effects of the sandwich plate system can be controlled and changed when the different magnetic fields are applied. Keywords: damping; rectangular plate, magnetorheological; elastomer; finite element method. 1. Introduction In recent years, the plate structures have received s great deal of attention because of the wide applications in many mechanical systems. Earlier analytical works on sandwich plate with constraining layer damping treatment can be traced back to Ross et al. [1]. The theory of the vibration bending for viscoelastic layered beam structures was presented by DiTatanto [2]. Then, Mead and Markus [3] calculated the forced vibrations of three-layer damped sandwich beam system with various boundary conditions. The analysis of sandwich constructions by finite element modeling was obtained by O’Conner [4]. Then, the Ritz method was utilized by Kanematsu et al. [5] to investigate the bending and vibration of rectangular sandwich plates and also conducted experiments to obtain the deflection and vibrational modes. Kung and Singh [6] showed the numerical results of the complex eigensolutions of rectangular plates with damping patches and studied new analytical, energy based approach that predicts the vibration characteristics of rectangular plates with multiple viscoelastic patches is presented. The magnetorheological (MR) materials have great potential in applications for smart materials and structures. The effects of the MR materials were first discovered by Rabinow [7] and the MR material had rapid change in their rheological properties and thus in the damping and stiffness properties with the applications of the magnetic fields [8]. Shiga et al. [9] studied the magnetoviscoelastic behaviors of composite gels. Then, the magnetoviscoelastic response of the elastomer composites consisting of ferrous particles embedded in a polymer matrix was obtained by Jolly et al. [10]. The applications for the construction of smart components had been previously presented by Yalcintas and Dai [11]. The Filed dependence of viscoelastic properties of magnetorheological elastomers was investigated and discussed by Bellan and Bossis [12]. Sun et al. [13] developed the analytical model for the case of sandwich beam structure with MR core layer based on the