Abstract:

The stability and bifurcation of the fluid film bearing rotor system with a squeeze film damper are studied using a nonlinear model. The oil film forces under free boundary conditions are solved by finite element discrete variational inequalities and iterative method based on complementary principle in linear programming. The mode synthesis technique is adopted to reduce the linear degree of freedom and the Newmark method combined with predictor corrector algorithm is presented to analyze the response of the reduced system. For determining the periodic solution, the Poincaré mapping is used to discretize the continuous flow, then the fixed point on Poincaré section and its stability are determined equivalent to the periodic solution and its stability respectively. Finally, the system is investigated experimentally by a rotor under the theoretic guidance. The results show that the squeeze film damper is very effective in preventing sub synchronous and non synchronous dynamic response, and the stability of the system can be improved greatly. It is also testified that nonlinear dynamical properties can be analyzed efficiently by the above theory and method.

Key words: squeeze film damper, fluid film bearing, ro to r, nonlinear stability, numerical analysis