Multiple limit-cycles shimmy characteristics of dual-axle steering mechanism considering the wheel alignment parameters

In this study, a nine degree of freedom mathematical model of dual-axle steering mechanism considering the wheel alignment parameters is established. Taking one multi-axle vehicle with dual-axle mechanism for example, the numerical method is used to analyze the effects of the wheel alignment parameters on multiple limit-cycles shimmy characteristics. The results show that the variation of the camber angle, the toe angle, and the caster angle will cause the maximum swing angles of first and second axle and the speed ranges of multiple limit-cycles shimmy to change. In addition, taking the caster angle as an example, the effects of matching of different wheel alignment parameters for the first and second axle on multiple limit-cycles shimmy characteristics were discussed. It is found that the effects which the caster angle of second axle having on multiple limit-cycles shimmy characteristics of dual-axle steering mechanism are much more greater than the caster angle of first axle's effects. This finding can provide theoretical guidance for suppressing multiple limit-cycles shimmy of the multi-axle vehicle with dual-axle steering mechanism.