АНАЛІТИЧНИЙ МЕТОД ДОСЛІДЖЕННЯ ПОЗДОВЖНЬО-КУТОВИХ КОЛИВАНЬ КОЛІСНИХ ТРАНСПОРТНИХ ЗАСОБІВ ІЗ НЕЛІНІЙНОЮ СИЛОВОЮ ХАРАКТЕРИСТИКОЮ СИСТЕМИ ПІДРЕСОРЮВАННЯ

Abstract

Influence of nonlinear restorative force of elastic elements and resistance force of damping devices of the suspension system on longitudinal-angular oscillations of the sprung part of wheeled vehicles is investigated. The basis of the research is the idea of asymptotic integration of equations with degree nonlinearity, which describe longitudinal-angular oscillations based on the use of special periodic Ateb-functions. The obtained analytical dependencies determine the law of basic parameters variation of the own damped oscillations of the sprung part as a function of the main power factors of the suspension system. The analysis of the obtained relations establishes that for the suspension system with the progressive law of restorative force variation of the elastic elements ( 0   ): ‒ the larger value of the oscillation amplitude the larger value of the own frequency (at the same values of static deformation of the elastic elements); ‒ the larger value of static deformation of the elastic elements (at the same amplitudes of the transverse angular oscillations and the parameter indicating the deviation of the elastic properties of the shock absorbers from the linear law –  ) the smaller value of the own frequency of oscillations; ‒ the overload, acting to the driver and the transported people, caused by the vibrations of the sprung part, is less than for the case of elastic elements with the linear law of restorative force (at the same values of static deformation of the sprung part) for small oscillation amplitudes. With regard to the suspension system with the regressive law of restorative force variation, the influence of oscillations of the sprung part is backward as for the progressive characteristic of the suspension system. As a result, it should be noted that the ergonomic requirements of operation are more satisfied by the progressive characteristic with static deformation of the suspension system м 2 , 0 at the change of the non-linearity parameter within 3 / 2 0   than the oscillation amplitude 16 , 0 025 . 0    a ; in the case of static deformation м 15 , 0 and 3 / 2 0   at the amplitude of transverse angular oscillations 2 , 0 05 , 0    a . As for the influence of the resistance forces of damping devices, they, at the real values of their parameters, slightly affect the law of time variation of the amplitude of the longitudinal-angular oscillations. The technique, based on which the above results were obtained, can be generalized to determine the response of the sprung part to the effect of single path irregularities, determine the critical speed of steady motion along curved sections of the way; the dependencies – during the design and modernization of suspension systems or the creation of a software product of the controlled suspension system.