Application of The Parameter Plane Method to The Analysis of Directional Stability of Tractor-Semitrailers

Abstract

This paper describes 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. 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 two tractor-semitrailer combinations with different brake systems are drawn on parameter planes as illustrative examples to demonstrate the utility of the method. In the analysis, the effects of normal load and braking effort on the stiffness of tires have been taken into consideration. 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.