Abstract:

Bolted connections are commonly used at discontinuous structures of aero-engine rotors， whose dynamic behavior under various loads such as heat and force have a significant impact on the overall engine vibration. However， research in this area is scant. Focusing on the slip issue at the connection interface under the combined effect of complex thermal loads and bolt preload， we first establish a finite element model based on a single-disc rotor experimental setup， followed by experiments designed to verify the model validity. Then， using this modeling approach and combining the connection characteristics of a certain type of aero-engine turbine disc and sealing disc， we develop a bidirectional thermal-solid coupling model of the discontinuous rotor to analyze the effects of thermal loads and uneven bolt preload on the connection interface. The results indicate that the circumferentially uneven bolt preload， under the combined effects of thermal loads and centrifugal force， can lead to circumferentially uneven deformation at the connection interface， causing interface slip and imbalance. Compared to the effects of instantaneous gradient thermal loads， the adverse effects are more significant when the discontinuous structures of the rotor are subjected to uniform thermal loads.

Key words: bolt preload, aeroengine rotor, discontinuous structure, thermo-mechanical coupling, interface slippage