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Effective damping treatment of the BIW panels of a vehicle is one of the important NVH enablers to attenuate in-cab structure borne noise and panel vibrations. Adding these damping treatments using physical testing methods at a later stage in a vehicle development program may lead to sub-optimal configuration, mass and cost of these treatments. To counter this, a validated simulation based approach to determine damping treatments must be deployed much upfront in a vehicle development program. Effectiveness of a damping treatment depends on identification of most appropriate application locations on the BIW panels of a vehicle being designed and at the same time on employing most appropriate materials having desired properties for these treatments. For identifying optimized locations of damping treatments in the development of a new Tata car program, simulation based composite modal strain energy method and physical test based sound intensity mapping technique were deployed.

Vehicle lateral shake during take-off is sensitively felt by customers when the vehicle is driven at a low speed under drive away acceleration. The take-off shudder is complained by customers during 1st and 2nd gear take off. Under an engine torque and half shaft angle, the drive-away shudder usually occurs during acceleration to a specific low speed at 1200 to 1600 engine rpm, which makes the vehicle shake severely. A thorough investigation with possible design optimization of mounting system, drive shaft joint and lubrication is done to reduce the lateral vibration. This paper focuses on a passenger car, the take-off shudder of which occurs at a speed between 20 km/h and 30 km/h. The test vehicle is a monocoque construction with front wheel drive east west engine. Vehicle lateral shake is observed during the low gear power train run up in Wide Open Throttle (WOT) condition.

An interior sound quality is one of the major performance attribute, as consumer envisage this as class and luxury of the vehicle. With increasing demand of quietness inside the cabin, car manufactures started focusing on noise refinement and source separation. This demand enforces hydraulic power steering pump to reduce noise like Moan and Whine, especially in silent gasoline engine. To meet these requirements, extensive testing and in-depth analysis of noise data is performed. Structured process is established to isolate noises and feasible solutions are provided considering following analysis. a) Overall airborne noise measurement at driver ear level (DEL) inside the cabin using vehicle interior microphone. b) Airborne and Pressure pulsation test by sweeping pump speed and pressure at test bench. c) Waterfall analysis of pump at hemi anechoic chamber for order tracking and noise determination.