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Among the key parameters that decide the success of a vehicle in today's competitive market are quietness of passenger cabin (in respect of both airborne and structure-borne noise) and low levels of disturbing vibration felt by the occupants. To control these values in body-on-frame construction vehicles, it is necessary to identify major transfer paths and optimize the isolation characteristics of the elastomeric mounts placed at several locations between a frame and the enclosed passenger cabin of the vehicle. These body mounts play a dominant role in controlling the structure-borne noise and vibrations at floor and seat rails resulting from engine and driveline excitations, and they are also a vital element in the vehicle ride comfort tuning across a wide frequency range. In the work described in this paper, transfer path tracking was used to identify root cause for the higher noise and vibration levels of a diesel-powered sports utility vehicle.

Tire modal performance plays an important role in passenger car NVH refinement which includes road induced noise. Work done in the past, enumerates testing methods, excitation technique applied and boundary conditions. It also includes Mode shapes, analysis results and study of variables affecting the modal performance of passenger car Tire. Here, in this paper an attempt is made to compare the experimental modal analysis results, obtained using two different excitation techniques for exciting tire. In the experimental modal analysis under discussion, the passenger car tire of type 175/65R14, was inflated up to 2.2 bar (32psi) pressure in free-free condition. Impact Hammer and Electro-dynamic shaker were used to excite the tire structure in radial direction. Single Input Multiple Output technique was used for excitation and response signal acquisition.