Modeling and Calculating on Two Stage Isolation System

This paper deals with vibration properties of a two stage isolation systems which is composed of rigid bodies.Differential equations are deduced by applying the multi-body dynamics theory.Mode superposition method and perturbation method are used to obtain the responses of linear and nonlinear systems respectively.And the results coincide with those obtained by Runge-Kutta method.Quantitative and qualitative analyses are applied to estimate the effect of small nonlinearity and height of isolators on a MTU diesel engine isolation system.It is revealed that the contribution of small nonlinearity can be omitted under operational environment,but that can not be left out if some isolators are broken.