Adaptive optimization design framework for vibration transfer suppression in aero-engine dual-rotor systems with shared bearing frame

The Shared Bearing Frame (SBF), subjected to concurrent excitations from both the high-pressure and low-pressure rotors, is highly susceptible to coupled vibration and vulnerable to potentially triggering fatigue cracking and other structural integrity failures. Therefore, this study develops a comprehensive dynamic model of the dual-rotor-SBF system, systematically characterizes its coupled vibration mechanisms, and thereby an adaptive optimization design framework for attenuating vibration transmission of the SBF structure of aeroengine based on the particle swarm optimization (PSO) method is proposed. First, a double-folded vibration reduction configuration is conceptualized to enhance inter-rotor decoupling. Second, the objective of optimization design is formulated to late the SBF modal frequency from the rotors’ sensitive frequencies, and PSO method is then applied, interfaced with the PyAnsys platform, to perform iterative optimization of the SBF’s detailed structural features. Finally, the vibration isolation efficacy and damping performance of the optimized configuration are quantitatively assessed; and metal rubber dampers (MRDs) are strategically incorporated to augment the system’s impact resilience. The results showed that the optimal double-folded configuration proposed in this study effectively mitigates inter-rotor dynamic coupling, the cross-rotor frequency-domain components at the HP and LP rotor supports decrease by 13.47 % and 21.40 %, respectively. Furthermore, the transmission of rotor vibration response to the casing and struts of SBF is substantially attenuated, and the peak vibration response amplitudes of the SBF inner and outer casings are reduced by 21.73 % and 22.90 %, respectively.