A Mathematical Model On The Dynamics And Stability Of Free And Forced Vibration Of An Automobile:- Duruojinkeya, Prisca U.

ABSTRACT

 In this research project we investigated the vibrational characteristics of a vehicle system, which is directly related to the ride comfort ofthe passenger and road handling. The suspension system of the vehicle is simplified as a quarter car model with two degrees of freedom. This model retains essentially many ofthe important characteristics of the more complex system in its response to random excitation. We studied a developed a mathematical model for the quarter-ear model to study the car dynamics during the passing over a circular hump of standard dimensions. The damping coefficient of the suspension was varied between 50 and 290 kNs/m to study its effect on the spring mass dynamics. Vehicle speed between 20 and 50 km/h was considered during the passing over the circular hump. We observe from our analysis that the vibration amplitude is decreased when passing over the circular hump due to the damping factor in the spring mass. Keeping the speed constant and varying the damping constant in the range 50 to 290 yields essentially the same graphical profile. This is true even when the velocity is increased from 20 to 50km/h. Stability analysis ofthe quarter car model was also investigated by the direct method, and it was observed that the system is asymptotically stable for the strictly negative eigenvalues obtained from a cubic polynomial equation.