Vibration refinement of two wheeler sub chassis and aesthetic parts due to engine unbalanced excitation forces

Two wheelers are important and essential transportation mode in India. Designing a motorcycle with better riding comfort and minimal vibration are thus a major challenge for engineers now a day. Engine and road excitations are two sources of vibration acting on motor bike or scooter. These vibrations are transmitted to chassis, sub chassis, aesthetic parts and then to the rider and pillion. Unwanted vibrations will create discomfort to the rider/pillion as well as produces noises and hence needs to be minimized. This study is focused on diagnosis and control of output vibration responses of sub chassis/aesthetic parts due to engine unbalanced excitation forces. There are numerous parameters of motor bike/ scooter that govern the vibration responses of sub chassis/ aesthetic parts. Engine unbalanced inertia force characteristics and their transmission to rider and pillion has been studied and reported here. Environmental benefits demands for a complete NVH refinement for lesser pollution/vibration especially that of an engine, chassis, sub chassis and aesthetic parts. The objective of current study is to develop an analytical approach to predict output vibration responses of sub chassis/ aesthetic parts in isolation of engine and chassis as they are mostly common from mass production model. Semi implicit procedure based on simulation and testing has been developed. Developed procedure is well supported mathematically and validated through physical testing measurement.