Construction of Shock Response Map for a Flexible Rotor-Bearing System With Mount System to Base Excitations Using the FE Transient Analysis Method

Abstract

Turbomachinery such as turbines, pumps and compressors, which are installed in transportation systems such as warships, submarines and space vehicles, etc., often perform crucial missions and are exposed to potential dangerous impact environments such as base-transferred shock forces. To protect the machines from such excessive shock forces, one may need to accurately analyze transient responses of rotors earlier on in their design stages, considering the dynamics of mount designs to be applied with. In this study, utilizing the generalized FE transient response analysis method of a flexible rotor-bearing system with a mount system to base-transferred shock forces, constructions of the shock response and static deflection maps of turbine rotor-bearing and mount system are devised, introducing the mount mass, resilient support stiffness and damping ratios to the counterpart rotor mass, bearing stiffness and damping and the mount system natural frequency. For the given turbine rotor system design a best available mount system design, composed of a mount plate and resilient support, can be readily selected from the constructed maps to meet the rotor’s shock response and mount’s static design limits. The shock response maps also show that for the same shock the FE flexible rotor model used herein yield a more compact light-weighed mount system design than the conventional simple rigid rotor model. Therefore, the shock response map approach in conjunction with the more complicated FE flexible rotor transient response analysis method is justified.