Publication

Power and Mobility (P&M)
2021

SIMULATION STUDY OF LIGHT-WEIGHTING EFFECTS ON RIDE QUALITY AND MOBILITY

by Bohumir Jelinek; Ethan Salmon; George Mason; Michael Gibson; Nathan Pachel; Walker Jarrell; Brent Towne

Abstract

We compared performance of a lightweighted and baseline vehicle and demonstrated how performance is affected by adjusting the spring and shocks using 2-D and 3-D simulations. 2-D lump-parameter model was constructed from physical vehicle parameters by transforming displacements and loads from the springs and dampers into wheel motion and spindle forces. For the 3-D model, a detailed model for each suspension was used including rotational inertia of moving parts. Ride quality was assessed for 16 ride-courses with varying RMS terrain roughness by finding maximum speed at which average absorbed power at the driver seat is lower than 6 W. Shock performance was evaluated by finding maximum speed for the driver not to exceed 2.5-G acceleration when riding over varying-size half-round obstacles. The forces on wheel axes and accelerations were measured for the vehicle dropped from the height of 6, 12, 18, and 24 in. Maximum longitudinal slope climbing capability was estimated on hard and soft soils. The spring rates and shock resistance were varied for the ride, shock, and the drop test to see how these variations affect test results.