Key Considerations for the Successful Specification and Design of Aircraft Interior Noise Isolators

摘要

Aircraft interior isolators are typically elastomeric mounts that reduce the structureborne transmission of noise from aircraft exterior sources to the cabin interior. Classical mass-spring-damper models do not accurately predict the noise attenuation performance of these isolators in the mid to upper frequency ranges where isolator non-linearity, resonances, and termination impedance influence performance. The use of experimentally derived transfer matrices, such as the Four-Pole Method, provide a more accurate prediction of noise attenuation by including frequency dependent input accelerations, isolator transfer matrices, and terminating structure impedance. Isolator characteristics such as stiffness and damping as well as the design of the isolator have a significant impact on the isolators transfer matrix. In addition, factors such as static and ultimate loads, temperature dependencies, installation requirements, and cost must be considered to develop a well balance design. This paper details the key considerations for the successful specification and design of aircraft interior noise isolators.