Project Definition:

Survivability and stealth are the major attributes for surface naval ships and submarines. One of the way for maintaining the survivability and stealth is to minimize the underwater acoustic signature of the ships. Among several contributions of the acoustic signature, machine vibration induced underwater noise is obviously one of the dominant components. In this project, our main goal is to determine a relationship between the machine vibration, structural vibration and underwater noise radiation and create a correlation between them by using coupled Finite Element Method (FEM) - Boundary Element Method (BEM) and also validating our results by experimental studies. Thus, outputs of this project will play a big role during the preliminary design stage of the ship construction.

                                      FEM model                                                                                    BEM model

Project Definition:

The interior noise inside the passenger cabin of automobiles can be classified as structure borne or airborne. In this study, we investigate the structure-borne noise which is mainly caused by the vibrating panels enclosing the vehicle. Excitation coming from the engine causes the panels to vibrate at their resonance frequencies and these vibrating panels cause a change in the sound pressure level (SPL) inside the passenger cabin and undesirable booming noise. In order to improve the passenger comfort inside the vehicle, it is critical to understand the dynamics of the vehicle and more importantly how it couples with the air inside the cabin. The design parameters of the most influential radiating panels (i.e., thickness) can then be optimized to reduce the interior noise based on the performance metrics selected during the design process.

Experimental modal analysis set-up for micro systems

Project Definition:

Micro Electro Mechanical Systems (MEMS) are among the new and emerging technologies of the future and have many applications in different disciplines. Predicting and improving the performance of such systems early in the design process can significantly impact the design cost and also improve the quality of the design.

Project Definition:

The structural design of the panels can be modified to improve the interior noise inside the passenger cabin of automobiles. However, such changes require considerable computational time especially when the structural models are very complex. In this study, the receptances of the original structure are used with the dynamic stiffness of the components that are added or removed from the original structure to perform the structural modification. The receptances of the modified structure are calculated using the structural modification technique. Then these results are used to perform the vibro-acoustic analysis of the modified structure.

Project Definition:

Suspension system of a vehicle plays an important role in maintaining comfort of the passengers by isolating and absorbing road shock from the passenger compartment. For that purpose, it is critical to understand the dynamics of the suspension system components and more importantly, how they interact with each other. In this project, we analyzed the effect of the dynamic properties (eg: mass, spring and damping) of the system components on the performance of the suspension system. We developed a methodology for defining the optimal relationship among vehicle suspension parameters and suspension performance indices. Our results show that the methodology developed in this study can be effectively used for improving the design of the vehicle suspension system.