FE modeling of rubber friction on rough roads
2008 (English)In: Proceedings of the WCCM8, ECCOMAS / [ed] B.A. Schrefler, U. Perego, 2008Conference paper (Other academic)
The cornering, braking, traction, rolling resistance and wear performance of tires depend on the generatedfriction forces. These friction forces depend not only on a specific compound, but also on theunderlying road surface. One of the challenges in numerical simulations is a correct prediction of thesefrictional forces. In commercial FEM packages, where usually only the Coulomb friction model ispresent, the surface roughness is not accounted for. It is well-known that for cornering under high slipangles the results with a Coulomb friction model are less accurate. By incorporating surface roughnessa more realistic friction model can be obtained, which should provide a better correlation between FEAand real road experiments.Recently a theory for contact mechanics and sliding friction of rubber has been developed (see Persson, ). In this work hysteresis friction is assumed, which is caused by the viscoelastic modulus of therubber and the excitation of the road surface. It is possible to calculate a friction coefficient for a set ofsliding velocities considering the mechanical-dynamical material properties and the specific roughnessof the interacting surface.To illustrate this approach an Laboratory Abrasion and skid Tester (LAT 100, ) is used, see figure 1.In this setup a small solid tire, with adjustable slip angle, is pressed on an abrasive disk. The appliednormal force on the tire, temperature, speed and surface texture of the disk can be controlled. Thepresent friction between the abrasive disk and tire drives the tire and the resulting forces are measuredwith a tri-axial force sensor.The relevant parts of this setup are modeled in ABAQUS , taking into account the non-linear materialbehavior, see figure 2. A 2D cross section of the tire is revolved to create the 3D model. To evaluate thesteady state performance of the wheel under different slip angles, the steady state transport capabilityof ABAQUS is used. Therefore only a dense mesh in the contact area is required, which makes this anefficient approach to calculate the responses.For the contacting surface in the FE model a smooth rigid surface is used. The effect of surfaceroughness is incorporated in the obtained friction model, using the method proposed by Persson, andis implemented into the user-subroutine FRIC. The implementation of the friction law itself is doneanalogous to a plasticity material model by using a return mapping algorithm. Therefore the slidingvelocity is split into a small elastic and an inelastic part .Finally the results of this method are compared with the available Coulomb model in ABAQUS andmeasured side-force characteristics on the LAT 100.
Place, publisher, year, edition, pages
tire road interaction, contact mechanics, FEM
IdentifiersURN: urn:nbn:se:kth:diva-72798OAI: oai:DiVA.org:kth-72798DiVA: diva2:488122
8th.World Congress on Computational Mechanics (WCCM8). 5th European Congress on Computational Methods in Applied Sciences and Engineeering (ECCOMAS 2008). Venice, Italy. June 30 –July 5, 2008
QC 201205142012-02-012012-02-012012-05-14Bibliographically approved