Abstract
Stiffness and damping properties of tyres are needed for every tyre simulation model. Simulation has become everyday tool on offroad vehicle and mobile working machine development that increases need for more accurate tyre parameters. This paper describes measurement device capable of measuring stiffness and damping properties of heavy tyres. Results of three tyres´ measurements are presented and discussed.
Developed device is able to measure longitudinal, lateral and vertical stiffness. During vertical measurements tyre can be rolled back and forth. All the forces are generated smoothly with hydraulic cylinders and they can be applied simultaneously. Dynamic stiffness is measurable on vertical direction. The damping as a function of frequency is derived from the dynamic stiffness.
Three different heavy tyres were measured with the device and the results are fitted for tyre model purposes. Results show that the device is accurate for these measurements even there are challenges with definition of starting of slip during the measurement. From the results can be seen that lateral force doesn´t have effect on longitudinal or vertical stiffness and vice versa.
Keywords: Tyre, offroad, stiffness, damping, measurement