Modal Analysis is a well established technique which defines the inherent dynamic properties of the structure. At the same time the experimental harmonic analysis by shaker method is also a very important tool in solving some of the engine induced vibration problems in the automotive structure. Computer simulation technique using finite element methodology has been very effective tool in simulating the problem. However the right combination of these techniques has been a tricky situation. The paper describes the methodology of using right combination of these techniques to reduce the motorcycle chassis vibration which are induced by engine and drive-line excitation in minimum time. The method involves the Finite Element Modelling with shell elements, experimental harmonic analysis with frequency sweep upto 600 Hz, validation of the FE model, animation techniques and find out correct modification to fine tune the structure to eliminate the engine induced vibrations in the frame.
The methodology adopted here gives the reduction of the engine induced vibration in the range of 80 to 89%, giving very smooth ride, reducing vibrations at the handle bar, seat and foot pedal locations.