(State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China)
To analyze the blade/casing rubbing-friction process of aero-engine, a blade/casing rubbing-friction model is established based on the finite element method. The stress,deformation,temperature characteristics of blade/casing under multiple rubbing are studied, and the dominant factors of thermal deformation caused by rubbing are explored and analyzed. The rubbing-impact between blade tip and casing of aero-engine will increase the temperature of the contact interface friction, which will not only change the interface temperature state, but also cause additional thermal strain and thermal stress of blade/casing through thermal deformation. Interfacial frictional heat changes the temperature and also induces thermal expansion strain of the casing and blades. The blades show an elongation trend and the casing show a partial upward arching trend after being heated. After the blades have rotated once, the casing generally shows a tendency to arch toward the blades. However, the deformation of the blade tip due to the inward arching of the casing not only does not extend, but is compressed and shortened by the casing, and expands in the width direction at the same time. The superimposed effect of the casing and blades after being rubbed and heated results in additional compressive stress between the blade tip and the casing. At the same time, the cause of thermally induced strain stress mainly comes from the effect of friction heat in the casing. Therefore, the friction heat of the casing is the main source of longitudinal displacement and longitudinal stress.