Energy-iteration Method for Nonlinear Oscillation of a Passively Vibration-isolated Body
Tang Jinyuan(1),Zhou Yifeng(2),He Xuhui(2)
(1 School of Civil Engineering and Architecture, Central South University, Changsha 410083,China)
(2 School of Mechanical and Electrical Engineering, Central South University, Changsha, 410075,China)

Abstract: Seismic responses of the body isolated by resilient material with strongly nonlinear stiffness are investigated. The nonlinear stiffness characteristics of the vibration isolating material are described by a cubic polynomial function of the deformation. The nonlinear dynamic equation is developed as a forced damping Duffing equation. The energy-iteration method for strongly nonlinearau tonomous system is modified and then adopted to solove this non-autonomous problem with strong nonlinearity. The approximate analytic expression of periodicre sponse is derived, the relationships between amplitude-frequency and phasefre quency, and coefficient of vibration isolating are also obtained. Compared with the result from Runge-Kutta method, the example confirms the accuracy of the proposed method.
Keywords:vibration-isolating, strongly nonlinear non-autonomous system, energy-iteration method.