Analysis of jackknifing in articulated steer vehicles

The jackknifing instability of articulated steer vehicles is studied by using a virtual prototype of a real vehicle. This virtual prototype is used to get a better understanding of the vehicle dynamics during the conditions in which the jackknifing occurs. For doing this, the response of the vehicle, tire forces and slip angles and some of the motion variables are simulated and analyzed. Then, the effect of increasing the torsional damping at the articulation joint to alleviate the jackknifing is investigated. It was found that the large values of the torsional damping are required for a high reduction in the articulation rate. This is due to the large amounts of the energy generated during this undesirable motion that should be dissipated by the torsional damping.