Experimental Analysis of the Influence of Body Stiffness on Drivability and Dynamic Body Behavior with On-Road Experiments

As of today, multiple studies suggest a perceptible influence of the vehicle body stiffness on the drivability and steering feel. Most of them use subjective methods to score changes in stiffness but do not conduct further measurements to explain the underlying physical chain. This interaction between the body stiffness and vehicle dynamics is not fully understood and requires further research, especially in the on-center behavior and maneuvers of low-lateral dynamics. This research focuses on these two areas by measuring the steering inputs, the resulting vehicle response and the vibrational behavior of the body on a freeway and a comfort test track. Afterward, the main effects of different stiffening measures are analyzed and discussed. Regarding the influence on the steering feel, differences can be measured but seem too small to be perceptible for a normal driver. The magnitude of the effects is comparable to the influences of nuisance parameters, such as temperature or tire wear. The vibrational behavior of the vehicle body is subject to greater changes when modifications in stiffness are made. Additional research into the interaction of body stiffness and vehicle dynamics must be conducted to build further understanding of the physical chain. Furthermore, the objectification of subjective perceptions in this area is another crucial building block in providing simulative models that can replace prototypes.