Development of engineering methods for structure-borne noise specification and quantification in aircraft and rotorcraft cabins

飞机和旋翼机制造商集成了大量负责音调振动的系统，例如(i)飞机发动机在风扇和发动机核心转子频率处产生低频音调成分，（ii）旋翼机主转子传动在齿轮啮合频率处产生结构传递的中频音调，（iii）液压系统产生中高频音调成分，（iv）电气元件产生高频谐波。这些振动传播到飞机/旋翼机结构，并传递到内部饰板，进而将噪音辐射到机舱。这种噪音被称为SBN，是飞机/旋翼机内部噪音的主要来源，影响乘客的舒适度，增加机组人员的噪音暴露水平，降低他们的沟通能力。然而，如果振动系统、接收结构和它们之间的接口在产品开发阶段得到很好的指定和设计，这些烦人的SBN可以得到缓解。该项目的总体目标是开发和验证通过集成振动系统预测飞机/旋翼机机舱产生的SBN的工程方法。这些方法将以现有的SBN方法（即基于频率的子结构和基于组件的TPA）为基础，这些方法由于难以在实践中应用，在机械工程界没有得到广泛应用。因此，该项目的目标是研究、扩展和验证这些方法，特别是针对航空航天集成系统和结构，重点关注SBN预测目标精度所需的复杂程度。三家工业合作伙伴将获得一个工程工具，以及专用于其SBN挑战的相关方法和指标。这个知识工具箱将使他们能够更好地在整个产品设计周期中整合SBN设计挑战

Aircraft and rotorcraft manufacturers integrate a high number of systems which are responsible for tonal vibrations such as (i) aircraft engines generating low frequency tonal components at Fan and Engines core rotor frequency, (ii) rotorcraft main rotor transmission generating structure-borne mid frequency tones at gear mesh frequencies, (iii) hydraulic system generating mid to high frequency tonal components and (iv) electric components generating high frequency harmonics. These vibrations propagate into the aircraft/rotorcraft structure and are transmitted to the interior trim panels that, in turn, radiate noise into the cabin. This noise, referred to as SBN, is known to be a major source of aircraft/rotorcraft interior noise that affects passengers comfort, increases crew member noise exposure level and decreases their communication ability. However, these annoying SBN could be mitigated if vibrating systems, receiving structures and interfaces between them were well specified and designed during the product development phase. The overall objective of this project is to develop and validate engineering methods for predicting SBN generated in aircraft/rotorcraft cabins by integrated vibrating systems. These methods will be based on existing SBN methods (i.e., Frequency Based Substructuring and Component-based TPA) which are not widely spread in the mechanical engineering community because they are difficult to apply in practice. The objective of this project is in consequence to investigate, extend and validate these methods specifically for aerospace integrated systems and structures focusing on the degree of complexity required for the targeted accuracy on the SBN prediction. The three industrial partners will be provided with an engineering tool together with the relevant methodologies and metrics dedicated to their SBN challenges. This knowledge toolbox will allow them a better engineering integration of SBN design challenges all along the product design cycle.**