Truck Tyre Vibration Behaviour. Measurements and High Frequency Modelling

Licentiate thesis, 2006

To facilitate tyre-road noise prediction, a computationally efficient high frequency tyre model is needed. Such models are always a compromise between the desired accuracy and the need for simplicity. In addition the accuracy of models is often limited by the quality of the input data available. For passenger car or truck tyres, a complete set of input data can be obtained only from the tyre manufacturer. However, this may not always be possible and one has to rely instead on approximate material data obtained from the careful study of experiments conducted on tyres. Although much research is available for passenger car tyres, less attention is paid to truck tyres. The work described in this thesis has the goal to close this gap by an experimental investigation of the vibrational behaviour of a truck tyre exposed to external forces. Driving point mobility and transfer mobility measurements are made to understand the behaviour of truck tyres, to gain insight into what may be the most suitable way to model truck tyres, and to extract material data for this modelling. A methodology was developed, which allows for the calculation of key tyre parameters, such as total bending stiffness and Young’s modulus from driving point mobility. These parameters are used in a 3-D orthotropic double-plate model based on elastic field equations as developed for passenger tyres. A WFEM model is also used to understand the limitations of modelling a tyre as a structure with homogenous geometry (i.e. thickness and material properties identical over the whole cross section). Results from the 3-D orthotropic double plate model are compared with measured tyre response functions. One can conclude from these results that the data obtained from measurements, as well as the model, can successfully be used later for simulation of contact forces in the tyre-road noise prediction models.