APPLICATION OF THE PARAMETER PLANE METHOD TO THE ANALYSIS OF DIRECTIONAL STABILITY TO TRACTOR-SEMITRAILERS.

The application of the parameter plane method to the study of the effects of design and operational parameters on the directional stability of tractor-semitrailers is described. The location of the fifth wheel, loading conditions of the semitrailer and cornering stiffnesses of tires are taken as parameters in the analysis. Stability boundaries for a tractor-semitrailer combination with an ideal braking system are drawn on a parameter plane as illustrative examples to demonstrate the utility of the method. It is shown that the parameter plane technique can provide the designer with a convenient method to evaluate the relative significance of various design and operational parameters to directional stability.