The paper presents a certain method of analysing the dynamics of a belt transmission. A flat transmission model developed by us was presented. For the analysis, it assumed the transmission 5PK belt. A discrete belt model, being a system of rigid beams interconnected with flexible and shock-absorbing elements, was used. To account for the mutual influence between the belt and pulleys, the Kelvin–Voigt contact model was used. The GMS friction model was also implemented, which allows all basic known friction phenomena to be taken into account. For this purpose, the vector of generalized coordinates was expanded with additional sub-systems of coordinates modelling the flexible belt-pulley connection. Moreover, two additional cases of a sudden transmission start were presented: with values of driving and resistance torque not causing a significant slip in the transmission as well as values of torque that cause slip.

Two algorithms which allow one to take an uneven road surface into account in the vehicle dynamics analysis are presented in the article. Their essence is to determine the position of the contact point of the tire model with the uneven road surface. According to the concept of the authors, the names of the algorithms are to refer to the essence of the matter of the procedures assumed. The first of them – named Plane – can be used while considering the continuous model of the surface obtained by use of “the bicubic interpolation” taken from computer graphics, and the second one – named 4Points – in the case of the discrete model of this surface, developed especially for needs of the methods presented. In the work, it is assumed that only continuous changes of the road profile, without its possible abrupt changes, e.g. in form of a transversely placed threshold of sharp edges, can be considered. Therefore, the mapping of the road surface, obtained in the case of including its both models, is smooth. The developed algorithms are used to analyze dynamics of a technical rescue vehicle which can drive in terrain conditions.

A method of a dynamic analysis of a special kind of trailers with the central axle (axles) towed by truck is presented in the paper. Within the method, vibration and also strength calculations of frames and other components of the selected trailer can be carried out. Interface of MSC Adams software, for the dynamic analysis of mechanical systems, and NX Nastran/Femap software, for the finite element method (FEM) analysis, was used. The information transfer between both types of the software was realised within this interface. In the approach proposed, a significant reduction of degrees of freedom of the FEM model of the trailer frame was performed based on the Craig-Bampton method. Some numerical results were verified experimentally by using a trailer towed by a truck driving on the test track. The main goal of the proposed method is to ensure the reliability of the designed trailers in traffic conditions.