The vibration features from rubbing between rotor and casing for single-shaft gas turbine engine are well known and have been studied by many researchers.The dual-shaft engine has two shafts with different frequences in the engine system.An improved model and calculation method are provided

based on the mathematical models derived by the former researcher on rubbing of rotor and stator.The vibration characteristics for some types of rubbing for the dual-shaft engine are analyzed and discussed.The theoretical results are consistent with data measured on a dual-shaft aircraft engine.