Nonlinear dynamics analysis of the attachment system and design of variable stiffness connecting bracket based on the complete aero-engine system

During the operation of the aero-engine, the attachment and brackets are subjected to various complex internal and external loads, which can pose risks to the structural integrity of the engine. To address this issue, this paper introduces a variable stiffness bracket designed for vibration reduction in the attachment system. Firstly, a finite element model (FEM) of the aero-engine was established using the Lagrangian method, incorporating the dual rotor-bearing system and bracket-attachment system. Subsequently, the vibration response of the system was solved using the Runge-Kutta method. The sources and propagation paths of vibration within the system were identified. Lastly, leveraging the material properties of Shape Memory Alloy (SMA), a stiffness-adjustable bracket for the aircraft engine was proposed to achieve active vibration reduction in the system. The results demonstrate that the variable stiffness bracket effectively reduces the resonance amplitude and frequency in the attachment system, exhibiting excellent vibration reduction and isolation capabilities.