Experimental investigations on tractor tire vibration properties

Abstract

Vehicle vibrations have raised articulate awareness in agricultural industry during the last years. Especially, the legal basis with the EU directive 2002/44/EC and its implementation into national law with the corresponding ordinance have sensitized the manufacturers concerning the vibration behaviour of their vehicles accompanied with an increasing demand for ride comfort by the customers. Furthermore, vehicle components’ stress due to vibration and shock is also significantly dependent on the tire’s vibration characteristics. Only an optimized design and combination of the vehicle components can reduce vibrations and improve ride comfort and endurance strength. In this thesis mechanical vibrations in the ride comfort frequency range between 10 Hz and 80 Hz are regarded. For the investigations a new mechanical shaker device has been developed and single frequency force excitations in the mentioned frequency range can be applied to a rolling tire. From excitation and response of the system it is possible to identify the vibration modes of the rolling tire. The shaker is designed to be applied both to a flat-belt test stand and a research tractor. Additionally, uniformity and cleat tests have been conducted with the research tractor in order to compare shaker, tire and impact excitations.