Research Projects

Functionally graded (FG) panels have gained popularity to be used as structural components in the aviation industry, such as, in rocket nozzles, wings, landing gear doors, engine nacelles, etc.. The structural components used in aerospace structures are often subjected to aero-dynamic and/or dynamic mechanical forces which leads to excessive vibration in the FG panels which may lead to overall structural failure. Moreover, FG panels used in wings, landing gear doors often generate huge acoustic loading due to this excessive vibration. This can be detrimental to sensitive on-board instruments as well as overall structures and also harmful for crew member’s health. It is to mention that these structures often operate in extreme environment characterized by high temperature and presence of moisture. These harsh environmental conditions can drastically alter the dynamic properties of these FG panels which in turn increase the vibration of these panels and also sound radiation and transmission through them. Given these challenges, it is crucial to carefully examine the vibroacoustic behaviour of FG panels in extreme environment. Consequently, controlling vibroacoustic responses of these panels is crucial for protecting crew members, sensitive equipment and the overall structure from potential damage caused by excessive vibration and noise. To address these challenges posed by excessive noise and vibration, various passive control strategies are conventionally employed which typically involve the use of damping materials, acoustic insulation, and specialized barriers that absorb or block flexural and sound waves. However, most of the traditional techniques rely on heavy materials, which can increase overall weight of the structure and negatively impact fuel efficiency. The state-of-the-art techniques for passive noise and vibration control include the use of metamaterials. Metamaterials, although effective in attenuating vibroacoustic response in a structural panel by creating a periodic arrangement, mostly needs to be externally attached to the host structure. However, this external attachment is often difficult and challenging in a panel used in aircraft and/or spacecraft structures. To address this limitation, we are exploring innovative approaches by employing the concept of acoustic black hole (ABH), thereby eliminating the need for external attachments. Conventionally, the ABH in a structure is realized by gradually reducing its thickness to near zero in a certain region which traps the flexural elastic waves. However, the implementation of geometrically developed ABH effects poses several challenges, primarily related to manufacturing limitations and structural integrity. Hence, it can be hypothesized that the ABH formed through a material gradation in a FG panel is capable to attenuate its vibroacoustic responses. The proposed project thus aims at evaluating vibroacoustic responses of a FG panel in extreme environment and subsequently developing the ABH effect through in-plane and out-of-plane variation of material gradation in the panel through numerical and experimental investigations to attenuate its vibration and acoustic responses. We aim to achieve this by incorporating ABH effects via functional gradation of materials without reducing the thickness of the panel, thereby maintain the structural integrity. The approach will bring a breakthrough in the state-of-the-art by averting the conventional means of reducing the structural thickness at certain zones to create an ABH effect, thereby retaining the structural integrity. The numerical design of such FG-ABH panel will be supplemented by the fabrication of a prototype through additive manufacturing. The anticipated output of the proposed research work in terms of the developed FG-ABH panel will pave the industry-ready solution for critical applications in the aerospace and aviation industries.