Assessment of Track Chain Tensioning on the Vertical Dynamic Behaviour of a High-Speed Tracked Vehicle

In this paper, the influence of tensioning force of the track chain on the dynamics of a high-speed tracked vehicle is investigated, through a sensitivity analysis. The tensioning force is responsible of two different effects: the variation of the track chain geometry, since the tensioner acts on the position of idle gear, and the variation of the stiffness of the connections between two different track assemblies. In this paperwork only the second aspect is modelled, connecting two adjacent track assemblies with beam elements, including a constant pre-tensioning, depending on the tensioner force. The vehicle model, comprising sprung and unsprung masses, torsional bars and the two track chains is realised in an in-house developed open-source FEM code. The performed analyses include the evaluation of natural frequencies and mode shapes, and the vehicle vertical dynamics, considering a condensed model to reduce computational efforts. The impact of tensioning is examined within the frequency domain, focusing on several critical acceleration frequency response functions of the vehicle under synchronous excitation caused by road profile input. The presented outcomes have proven a substantial effect of chain tensioning on the vibrations of the above-ground track assemblies, with a minimal influence on the vehicle sprung mass dynamics.