Virtual damping for vibroacoustic design of future launchers – ARIAN
Design of assembled structural interfaces for the vibrational comfort of vehicles
- Design of highly damped interfaces for vibrations.<br /><br />- Given the intrinsically weak damping in subassemblies (materials,...), energy dissipation occurs primarily in the interfaces. The idea is to design and optimize the damping in these interfaces in order to improve the vibrational comfort of vehicles consisting in assembled substructures. <br />
Design of comfortable vehicles for the future having very low vibrational levels
The control of damping is a major problem in the dimensioning of space and land vehicles. By reducing or eliminating costly structural tests, the absence of damping models can lead to over designing the structure instead of insuring its vibration comfort, which constitutes the main objective of the project. An improvement in the a priori knowledge of damping will allow structures to be dimensioned adequately by properly designing the damped interfaces.<br /><br />All vehicles, air or land, generate vibrations which can affect the reliability and the overall life of the vehicles, as well as disturb the transported materials and passengers. The objective of this project is to design and optimize certain interfaces between the vehicle subassemblies which are potentially highly dissipative in order to reduce the vibrational levels.<br />
This project is devoted to the prediction of damping for future air and land vehicles, and more specifically to bolted interfaces between composite structures for which friction between parts can lead to significant energy loss. The originality of the project consists in proposing a predictive methodology to calculate the vibration levels in these structures based on a virtual testing strategy which allows to predict damping in the low and medium frequency ranges while reducing or even eliminating real tests so as to diminish design and production costs. Robust design tools will also be integrated into the approach in order to account for uncertainty and evaluate the degree of confidence that can be accorded the virtual prototyping process.
Computational burden is an important challenge in virtual prototyping under uncertainty and will be addressed using well adapted and robust techniques in order to render this phase of the project compatible with realistic and competitive design delays.
The methods developed in the framework of this project can also be applied to other industrial sectors (aeronautics, rail, offshore,...).
“The ARIAN project deals with the numerical design preparation of the next generation of Launchers ARIANE6. For confidentiality reasons in such a sensitive sector, the industrial partner EADS-Astrium together with the involved partners is submitting the following proposal in French.”
The structural damping optimisation and mastering plays a fundamental role in the aerospace launchers design and specifications. In this case, the lack or even the absence of structural full size tests in the design and assembly stage leads often to overestimation of damping value. To improve the dynamic comfort of payloads, damping treatments are employed at the final stage of the launcher assemble. That increase the design cost through added unwanted mass. EADS-ASTRIUM developer and designers are seeking for an efficient way to handle the damping issues in launchers design at early stage of the developments.
This project is devoted to the damping prediction for the next generation of launchers ARIANE6. The project deals specifically with damping management of bolted links between composite structures. In such interfaces, friction between the different sub-elements induces a large amount of dissipated energy. Le project main originality is to propose a virtual damping prediction method and a virtual testing strategy associated to the vibroacoustic behavior of payloads in the low and mid-frequency range. This integrated virtual damping design strategy is supposed to be real testing free.
The robustness aspect of the virtual damping prediction will be also considered in this project. Precisely, the lack of knowledge associated to the virtual testing inputs will be taken into account in order to provide the margins associated to the design and to uncertainties.
Computation cost and time is a real challenge in virtual prototyping, specifically when uncertainties are to be considered. Reduction of time consumption will be a big issue the project will deal with. This will allow the virtual damping design and optimization realiste at the early stage of the vehicles design through specific model reduction and metamodeling strategies suited.
Monsieur Noureddine BOUHADDI (Institut FEMTO-ST) – firstname.lastname@example.org
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
Université de Franche-Comté (UFC) Institut FEMTO-ST
Ecole Centrale de Lyon (ECL) Laboratoire de Tribologie et dynamique des Systèmes (LTDS)
ENS Cachan Laboratoire de Mécanique et Technologie (LMT)
Astrium-ST ASTRIUM SAS
Help of the ANR 441,345 euros
Beginning and duration of the scientific project: October 2012 - 42 Months