Anagrafe della ricerca

To compete in the global market, the design of modern aircraft is driven by the continuous improvement of the safety and cabin comfort. It is well known that the human factor represents one of the leading causes of accidents across all transportation modes. Among all human factor aspects, fatigue is one of the most critical in commercial aviation. In this context, Noise and Vibration (N&V) can deeply affect flight attendants and pilots in cabin and cockpit. On the other hand, airliners have also paid great attention, over the past twenty years, to the influence of N&V on the comfort of passengers due to longer trips and to passenger expectations, viewing the comfort as one of the main aircraft quality indicators. Thus, in the framework of a human-centered design philosophy, the main target of the project is to achieve an improved design of cockpit and cabin environment by considering the effects of vibration and noise on pilot performance and passenger comfort. To this aim, the project is articulated into three different sub-targets: 1. simulate the main N&V conditions that can occur in the aircraft by defining a high-fidelity vibro-acoutic model; 2. develop innovative passive treatments for lining panels of cockpit and cabin mainly based on the use of acoustic metamaterials; 3. optimize the design of acoustic metamaterials according to the technical constrains deriving from the aeronautical application. Since low frequencies are especially difficult to absorb with conventional materials, due to the order of magnitude of the wavelength, metamaterials are here proposed for the broadband soundproofing of fuselage. Metamaterials derive their properties from their newly designed microstructures with repeating patterns - not from the properties of the materials they are composed of – hence, the need of efficient numerical tools for their dynamic characterization (coupon level) and vibro-acoustic simulation at large scale (panel level). According to the wavelength, two basic approaches will be employed for the numerical analyses: deterministic in the low-frequency range by the use of finite element method; statistical in the mid to high frequency range where energy-based methods are more appropriate, as the Statistical Energy Analysis (SEA). Summarizing, the concurrent targets in terms of ‘N&V simulation’ and ‘metamaterials design’ will be processed for the lining panels development and weighted to define a high-fidelity virtual environment through a ‘multidisciplinary optimization process’ built on aeronautical requirements (weight, thinness, mechanical strenght, fire resistance etc.). An important strength of the project will be represented by the high accuracy of the vibro-acoustic model that will be validated through experimental tests at both coupon scale (impedance tube) and large-component scale (reverberant room).