1. Yantai University, Yantai 264005，China； 2. Key Laboratory of Advanced Manufacturing and Control Technology in Universities of Shandong, Yantai 264005, China； 3.Dalian Universities of Technology, Dalian 116024, China
Abstract：The dynamic model of simplified-concentrated-mass based Jeffcott rotor system with slowly-varying mass is build. Analytic processing for rotor system with slowly-varying mass is introduced by adopting the asymptotic method. And the analytic solutions for response of the rotor system are deducted detailedly. With the analytic solutions and Reassigned Morlet scalograms, the nonlinear dynamics of rotor system with slowly-varying mass are discussed. The specific nonlinear dynamic characteristics for rotor system with slowly varying mass can be referred for research on slowly-varying parameter system and diagnosis of corresponding faults.