ABSTRACT
The level and quality of noise experienced by occupants in transportation systems
such as military vehicles are issues of increasing concern and are among the major
challenges of the automotive industry apart from reducing vehicle mass and product
recyclability. Researches have shown that the vibration behaviour of panels that
enclose the passenger cabin can affect low-frequency interior noise resulting in
adverse effects on the human body or vehicle occupants. However, a compelling
amount of anecdotal evidence reported that the characterisation of structure-borne
panel vibration and its subsequent noise emission characteristics employing
recyclable, sound absorbing, natural fibre composites with an Acrylonitrile Butadiene
Styrene (ABS) matrix has not yet been studied within a vibro-acoustic setting. Thus,
the primary contribution of this original work was to implement a novel poroelastic
natural fibre damping material into a flexible numerical model to predict and improve
the vibro-acoustic performance of a vehicle's cabin when provoked by an external
structural forcing function. With reference to an undamped vehicle, a discrete,
frequency domain numerical model is developed and experimentally validated based
on frequency response data. It was observed that the proposed numerical model
effectively and efficiently simulates the noise levels within the vehicle model while the
newly developed natural fibre material does reduce cabin noise to a perceivable
degree.