The non-synchronous responses of rotor-bearing system with strong nonlinear elements

This paper presents a new approximate method for solving the non-synchronous respenses of rotor-bearing system with strong nonlinear elements. First, the strong nonlinear elements are substituted by the sum of the equivalent linear elements and the equivalent external harmonic forces when the motion state of the system is non-synchronous([1]). Then, from Routh's equation with non-holonomic constraints, the defferential equations of motion of the system are derived by the modal synthesis method. Finally, a set of algebraic equations for solving the non-synchronous response is obtained. Numerical results show that the equivalent solution is very close to the nonlinear solution, and the computing time is saved obviously. This paper's method is especially fit to analyze non-synchronous response of a large scale rotor-bearing system with strong nonlinear elements.