<div class="htmlview paragraph">Geometrical stiffening of the panels via rib design are considered due to vehicle design requirement and vibro-acoustic considerations. This paper studies the damping effectiveness of different damping treatments (extensional, shear damping structural damping layer - based on friction and inelastic collision) for flat panels and geometrically stiff panels.</div> <div class="htmlview paragraph">This paper considers the significant panel characteristics, damping efficiency of extensional and constraint layer dampers and structural damping layer. The overall vibro-acoustic reduction is measured over the low and medium frequency regions. The damping effectiveness on the panels is characterized by average vibration reduction, and frequency response function (FRF). The in-vehicle damping performance is measured experimentally with vibration excitation on in-vehicle size body panels.</div>