A Numerical Evaluation of the Suspension and Driveline Dynamic Coupling in Heavy Trucks

This study provides a numerical evaluation of the dynamic coupling that exists between the powertrain, suspensions, and tire dynamics in class 8 trucks. The spatial dynamics of the driveline, including the offset angels that commonly exist in practice, are modeled along with a lumped-parameter representation of the suspension and tire dynamics in vertical, longitudinal, and torsional directions. The model is used to show how the suspension dynamics and the angle change that it causes in driveline geometry can affect the vibrations resulting from the powertrain. The numerical model is also used for a parametric study in which the effect of various suspension and powertrain parameters on the dynamic coupling that exists between the two is evaluated. The parametric study indicates that, among more than twenty different parameters that are evaluated, reducing the driveline angles, increasing the drive axle suspension stiffness and damping have the biggest influence on reducing powertrain-induced vibrations, as measured by the vehicle CG vertical and pitch accelerations.