Sensitivity analysis of chaotic vibrations of a full vehicle model with magnetorheological damper

In the present study, the chaotic response of a nonlinear 7-degree-of-freedom full vehicle model equipped with magnetorheological (MR) damper is investigated. The disturbance applied from the road to the vehicle suspension system is assumed to be sinusoidal with time delay between front and rear axles as well as left and right tires. By means of nonlinear systems stability theory, the probability of occurrence of chaotic behavior is demonstrated. By employing the modified Bouc-Wen model for MR damper, the equations of motion are established. These equations are then solved using 4th order Runge-Kutta method. In order to validate the numerical results, Poincare maps and bifurcation diagrams as well as frequency response diagrams are utilized for the full nonlinear vehicle model by substituting the MR dampers with nonlinear dampers as proposed in well-known studies; perfect agreement between the obtained results is observed. Then, the results are presented for the vehicle with MR dampers and the findings on the influence of MR damper are discussed. Finally, by using bifurcation diagrams, sensitivity analysis is performed to show the effects of various parameters on vehicle response. Numerical results presented in this study can be used in the dynamic design of vehicles and can serve as benchmark for future studies. (C) 2019 Elsevier Ltd. All rights reserved.