A novel vibration modeling method for a rotating blade with breathing cracks

作     者：XIE JingSong ZI YanYang ZHANG MingQuan LUO QinYuan 

作者机构：State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2019年第62卷第2期

页      面：333-348页

核心收录：

学科分类：08[工学] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Key Research and Development Program of China(Grant No.2017YFC0805700) the Key Project of National Natural Science Foundation of China(Grant No.61633001) the National Natural Science Foundation of China(Grant No.51775411) 

主　　题：vibration modeling rotating blade crack breathing model centrifugal effects 

摘      要：This paper proposes a vibration modeling method for a rotating blade with breathing cracks, considering the coupling of the centrifugal effects, the breathing effects and the crack effects. Firstly, considering the combined effects of the centrifugal stress and the bending stress, a crack breathing model for the rotating blade is proposed. Since the crack surface cannot provide the spanwise centrifugal tensile stress, an additional bending moment will be generated at the crack surface in the rotating ***, an additional bending moment caused by the centrifugal stress is then constructed. In addition, due to the discontinuity of the crack cross section, the additional stiffness caused by the centrifugal effects of the cracked blade will be smaller than that of the normal blade. Therefore, a correction coefficient of the centrifugal stiffness is built. Furthermore, based on the Lagrange equation and the assumed modal method, the vibration equation of the rotating blade with a breathing crack is established(RBC model), and a strategy is constructed for solving this vibration equation. Finally, taking the finite element model(FEM) as a reference, the vibration responses of the RBC model, the open crack model(OC) and the bilinear crack model(BC) are compared. The necessity of the RBC model is illustrated, and the accuracy of the RBC model is verified. The RBC model is a computationally efficient alternative to the finite element analysis for the rotating cracked blade. It can provide an important tool for the vibration modeling and the vibration analysis of the rotating shaft-disk-blade system with cracked blades.