Parametric evaluation of transmission characteristics in aircraft-like structures

The paper develops a model for the coupling between a beam and a ring which represents the joint between a wind and a fuselage ring frame. The model is used to study the transmission of structureborne disturbances from the beam to the ring. Such disturbances could arise on an actual aircraft due to a wing-mounted propeller and engine. The effects of joint placement and synchrophasing (synchronizing the phase of the propellers and/or engines) are studied as methods of noise control. The results show that the optimum phase shift between propeller inputs depends on the location of the joint between the wing and the ring frame. High and mid-wing designs generally experience lower levels of disturbance transmission than low-wing aircraft, but the combination of wing placement and phase synchronization determines the amplitude of structureborne transmission.