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In this paper, ITEMB team in the contest of the Clean Sky 2 framework, with the scope of a new architecture for the Main Landing Gear of a single isle aircraft type, presents its development in designing the two major item of the Main Landing Gear Bay that are the “roof” and the “rear pressure bulkhead” using pre-preg CFRP material. Typically, a lot of parts (metallic and also composite made) are involved in the two items manufacturing: the research effort has targeted the design of one piece structures consisting in a monolithic “roof” and “monolithic “rear pressure bulkhead”. The assembly of these ones takes advantages from a hole-tohole assembly supported by statistical analysis. The main expected advantages are the reduction of: both non-recurring and recurring cost, the overall flow time and weight saving. The ITEMB (InTEgrated Main landing gear Box) team has worked adapting a bag-to-bag technology to the geometrical and strength capability requirements of the component and outcome of the research (not yet concluded at time of issuing this paper) includes: A design principle supported by stress analysis for strength, stability and local main load introduction; A manufacturing trials campaign to reach the possess of a robust process; A limited coupons test campaign to demonstrate that no specific critical items exists in the design approach. Finally, participants have acquired a new design and manufacturing technique, applicable also to other Aircraft components upgrading their capabilities and European strength in composite structures manufacturing.

One of the most disturbing noise for passengers is related to the engine fan. This noise is mainly tonal and in the low-frequency range. Reducing its impact for the comfort of passengers is an important and challenging issue in aeronautics. One suitable way to reduce cabin noise is to use efficient thermal acoustic insulation blankets between the interior trim panel and the exterior shell. General Aviation Aircrafts, are generally equipped with a cabin poorly efficient both in terms of thermal and acoustic insulation; this due mainly to the not availability of the most innovative solutions or materials like those used on Large Passenger Aircraft. In this context the authors have faced this crucial issue within SPAIN Project “Smart Panels for SAT Aircrafts Cabin Insulation” which makes part of the Systems Integrated Technology Demonstrator (ITD) Program in EU Clean Sky 2. This project aims scientific and technological breakthroughs in the development and validation of new insulation treatments used in aircraft developing a thermo-acoustic insulation system with materials and innovative solutions highly efficient at an affordable cost for this class of aircrafts. According to the available materials on the market with high thermal and acoustic individual performance, SPAIN goal is to design, develop and test an efficient insulation panel suitable for the General Aviation Aircraft compliant with the technical specification in terms of and weight to performance, and cost to performance aspects. Another item that has been strongly worked on, is the integration technology of this solution with the actual interiors configuration with specific focus to maintenance aspects. A set of sandwich configurations have been designed for each specific area of the fuselage to fulfil the overall noise level target; preliminary test have been performed at coupon level and sub-assembly level to confirm the expected outcomes.

The aircraft is surely one of the most considerable invention that changed the transport-engineering field, since flying was already an ancient dream come true just a few years ago. Now it is really easy to reach many far places even if most people have no clue how flying is possible. However, as factories do, these large and faster and faster machines return a consistent amount of pollution every day. During take-off, engines reach the highest RPMs returning the most noise possible, and during landing, mobile surfaces produce a lot of aerodynamic disturbs releasing energy in the air while landing gears constantly produce drag in both circumstances. The need to be able to predict the sound emission of an acoustic source represents an extremely current engineering challenge: in particular, a numerical code that would let the user to listen noise produced by a flyover, since acoustic reports are just numerical statistics and spectrogram plots. In this paper, a numerical formulation is suggested for the prediction of the acoustic emission in the frequency domain. The main task of the project was to develop a program that makes dynamic analysis of the signal taking into account the source movement. Moreover, the simulations predicted the noise levels, thus explicitly accounting for the scattering acoustic effects of incidence and geometrical obstacles as well. Geometrical reflections and absorptions of certain frequencies depending on the material have been comprised in the model.

Smart structures represent of course a current challenge for the application on the aircrafts. Dealing for example with morphing and variable-shape structures, the skin needs to face extremely high strains, while withstanding the operational loads in order to ensure a smooth profile to the complete system. In this context, the authors led the design and manufacturing of carbon fiber-reinforced composite panels, including different filler infusions based on multi-walled carbon nanotubes (MWCNTs) technology. The vibro-acoustic tests have been carried out on an innovative formulation for the characterization of the damping properties related to such micro-handling treatments. The percentage of nano-filler has been chosen so as to be close to the percolation threshold of the material (about 5wt%). As a result of synergic collaboration between Smart Structures Lab of University of Naples “Federico II” and University of Salerno within H2020-MASTRO (Intelligent bulk MAterials for Smart TRanspOrt industries) research project, a multi-functional composite concept has been idealized and developed. The main purpose is to develop intelligent bulk materials for the transport field based on the novel concepts like self-sensing, self-deicing, self-curing, self-healing and selfprotection methodologies to enhance consumer safety, component life-span and performance while reducing maintenance and manufacturing costs. The functionality of the developed components will be demonstrated under relevant conditions at prototype level with special attention to the aerospace structures.

A growing attention has been recently devoted to the impact of the underwater noise field generated by shipping activities on the marine fauna. While in international treaties and conventions this problem is now well treated, from a technical point of view the quantification of the impact of underwater noise emissions from the ship is not yet consolidated. The program created allows the user to identify the sound rays generated by source and, between these, to find the beam nearest a receiver calculating the Trasmission Loss (TL). The user enters as input data the source position, the Sound Pressure Level (SPL) of the source, the depth of the backdrop, sound velocity profile, thickness of the layers in which the water column is divided, salinity, temperature and pH of sea water and the frequency of emission of the source to characterize the propagation environment. Through the Ray Tracing Theory, a technique of optical geometry that is based on the calculation of the path made by light the rays are shown on the screen. Then the rays closest to the receiver are identified and the program calculates the sound loss, divided into Geometrical Loss (due to distance between the source and the receiver), Dissipation Loss (due to the characteristics of the propagation environment) and Reflection Loss (due to the surfaces that delimit the field).In output the program will show the propagation field of the Sound Pressure Level through which in the future it will be possible to identify the emission limits to protect the marine fauna.

Among the wide contest of the train vehicles rolling noise evaluation, the aim of the paper is the development, implementation and experimental testing of a new method for roughness calculation according to FprCEN/TR 16891:2015 and the successive evaluation of the correction parameters of the measured rolling noise due to the presence of not compliant rail roughness. It is, in-fact, a very often operative condition, the execution of rolling noise tests over standard in-operation rails that are characterized by roughness profiles very different from standard one as those prescribed within the ISO 3095 procedure. Very often, this difference lead to the presence of an exceeding noise that needs to be evaluated and revised for a correct definition of the phenomena. Within the paper, the procedure implementation is presented and later on verified in operative experimental contest; forecasted and measured data are compared and successively commented.

Noise is often generated by pressure changes in the air induced by mechanical vibrations. The study of these phenomena is known as structural acoustics or, in a more fashionable way, virboacoustics. Vibroacoustics is the study of the mechanical waves in structures and how they interact with, and radiate into, adjacent media. In railway the most important noise source, based on fluid and structure interaction is the rolling noise. The aim of the paper is the development and implementation of a numerical method for the rail decay rate and combined roughness calculation according to the FprCEN/TR 16891:2015 and a subsequent evaluation of the excess noise level in accordance with the ISO/FDIS 3095: 2013. The tool, as a final results, will make possible the evaluation of the rail parameters without the involvement of long and expensive test campaign based on classical roughness measurement methods and will permit the compensation of the roughness induced excess noise level for a comparative comprehension of the acoustic experimental data.