Evaluation of Handling Characteristics of an Intercity Bus by Multi-Body Dynamic Simulations 2016-28-0178

Vehicle dynamics is the study of response of the vehicle to driver’s input. Various parameters like location of center of gravity (CG), suspension spring stiffness, wheel alignment parameters, etc. determine the handling behavior of the vehicle. This is a study to investigate the effects of aforesaid parameters on handling characteristics of an intercity bus using MSC ADAMS software tool. Handling performance is determined by evaluating various parameters such as understeer gradient, roll gradient, etc. Understeer gradient is influenced by various parameters like location of CG, tire cornering stiffness, etc. Roll gradient of a vehicle depend on various parameters like vertical stiffness of tires, anti-roll bars (ARB) diameter, location of CG, etc. As a part of this study, four different configurations of MBD models were built to investigate the effect of location of ARB on handling behavior of bus. Several vehicle dynamic tests are virtually conducted on the MBD model of the bus. It was observed that the magnitude of understeer gradient was more in case of bus with front ARB and less in case of bus with rear ARB compared to the bus without ARB. The roll gradient was observed to be minimum for the bus with both front and rear ARB and maximum for the bus without ARB and it was most sensitive to height of CG. The sensitivity analysis revealed that the bus tends to exhibit increased understeer characteristics with the increase in caster, camber, cornering stiffness of rear tires and weight distribution on front axle.