A Combined Effect of Frictional and Elastic Moment against Truck Turning on Running Stability of a Truck with Elastically Suspended Axles

In this paper, the author analysed the hunting of a truck when spring and friction are connected in series against truck turning. A describing function method is applied to the analysis of the truck hunting having a non-linearity, and the Frank-Koenig's method is used to search for a criterion of stability for polynomials with complex coefficients. And it is made clear that the turning stiffness of truck, the friction of side bearers, the supporting stiffness of axles, the slope of wheel treads and the creep coefficients between wheel and rail, have effects on the truck hunting. The results will be helpful for designing of cars. According to these results, the optimum value of the longitudinal supporting stiffness of axle and that of the lateral one to give the maximum speed of hunting are conerned with the magnitude of the turning amplitude of the bogie on the hunting. Besides, it is clear that to supplement both the turning stiffness and the irictional force has an effect to raise the hunting speed at large amplitude.