Equivalent modeling and vibration isolation design of wing-mounted engine structure

In order to research the vibration isolation characteristics and optimize isolator design of wing-mounted engine mounting structure, the theoretical analysis model and finite element model of engine mounting joint-pylon-wing structure were built. The modal verification and vibration isolation characteristic of the mounting structure was analyzed using finite element method. The dynamic response and vibration transmission main path under three typical load spectra was analyzed. The influence of isolator parameters and position on the engine mounting system isolation performance was also analyzed based on the vibration transmission path method. The results show that the peak response of vibration load under rotation frequency of low pressure rotor, rotation frequency of high pressure rotor can reduce to 22.03% and 14.65% by the mounting structure; the vibration transmission main path under rotation frequency of low pressure rotor is the engine-former engine mounting joint-pylon-wing while under rotation frequency of high pressure rotor is the engine-latter engine mounting joint-upper connection rod-wing. The vibration isolation rate of mounting system can reach 50.41% by reasonably setting the position of the vibration isolator, and even reach 70.67% when the frequency ratio of isolator is 5 and the damping ratio is 0.25. The installation position and the parameters of isolator must be appropriately selected to acquire optimal vibration isolation effect of the entire engine mounting system.