New tire model is under development in European Commission
research project called VERT (Vehicle Road Tire Interaction,
BRPR-CT97-0461). The objective of the project is to create a
physical model for tire/surface contact simulation.
One of the subtasks has been to develop a method for snow
surface characterization. The aim is simulate winter tire on snow
surface with FEM software. This kind of simulation has been earlier
done with snow model parameters from laboratory experiments.
A snow shear box device has been developed in Helsinki
University of Technology to measure mechanical properties of snow
in field conditions. Both shear and compression properties can be
measured with the device. With the device, a large number of snow
measurements have been done at the same time with VERT winter tire
testing in Nokian Tyres'' test track in Ivalo Finland.
Measurement data have been postprocessed afterwards and parameters
for material models have been evaluated.
Both shear and compression tests have been simulated with FEM
software with three different material models. Mohr-Coulomb,
Drucker-Prager and Cam-Clay material models have been used to
compare simulated results with measured ones. Afterward this
material model will be used in tire/snow contact simulation.
In this paper, Shear box device and measurement data will be
presented. Simulation results of different material models will be
discussed, and the best material model will be selected.