Stuart, J., Cassara, S., Chan, B., and Augustyniak, N., "Recent Experimental and Simulation Efforts to Mitigate Wobble and Shimmy in Commercial Line Haul Vehicles," SAE Int. J. Commer. Veh. 7(2):366-380, 2014, doi:10.4271/2014-01-2314.
Wobble and shimmy vibrations are commonly observed in commercial highway vehicles with solid-beam front axles. These vibrations are typically self-excited and manifest themselves as sustained oscillations about the kingpin and axle tramp.A study was initiated to investigate and quantify wobble and shimmy behaviors, with a primary focus on wobble. A cross functional team including test and simulation engineers evaluated a vehicle exhibiting these behaviors. The team developed an ADAMS model to reproduce the behaviors and developed a DOE to quantify the impact of variables and combinations of variables.The evaluation demonstrated that dynamic imbalance in the rotating masses is a primary source of excitation. Wheel run-out, caster angle, tire brand, tire wear and tire inflation are also significant sources. Future studies will use these findings to mitigate the concern.