%0 Journal Article %A M. Sasajima and T. Yamaguchi and Y. Koike and A. Hara %D 2012 %J International Journal of Mechanical and Mechatronics Engineering %B World Academy of Science, Engineering and Technology %I Open Science Index 71, 2012 %T Chaotic Oscillations of Diaphragm Supported by Nonlinear Springs with Hysteresis %U https://publications.waset.org/pdf/1556 %V 71 %X This paper describes vibration analysis using the finite element method for a small earphone, especially for the diaphragm shape with a low-rigidity. The viscoelastic diaphragm is supported by multiple nonlinear concentrated springs with linear hysteresis damping. The restoring forces of the nonlinear springs have cubic nonlinearity. The finite elements for the nonlinear springs with hysteresis are expressed and are connected to the diaphragm that is modeled by linear solid finite elements in consideration of a complex modulus of elasticity. Further, the discretized equations in physical coordinates are transformed into the nonlinear ordinary coupled equations using normal coordinates corresponding to the linear natural modes. We computed the nonlinear stationary and non-stationary responses due to the internal resonance between modes with large amplitude in the nonlinear springs and elastic modes in the diaphragm. The non-stationary motions are confirmed as the chaos due to the maximum Lyapunov exponents with a positive number. From the time histories of the deformation distribution in the chaotic vibration, we identified nonlinear modal couplings. %P 2349 - 2355