Contact analysis of road aggregate with friction using a direct numerical method

This paper deals with the contact of road surface aggregates with tangential tractions. The problem is modeled in static conditions with Coulomb’s friction. The aggregate is assumed perfectly rigid and is loaded on an incompressible elastic half-space. The contact problem is solved by means of a direct numerical method which is successfully validated for a spherical indenter. Then, the method is applied to three real road aggregates which surfaces were measured. The normal and tangential stresses at the contact interface are studied. The contact on a single aggregate is similar to multi-asperity contact and the contact areas can be finely observed. The adhesive and sliding contact areas were also identified on each contacting asperity. Relationships between the total force and displacement can be approached by simple functions and ranged between the solutions for a sphere and a cone. The conclusion is that the developed numerical method and the identified contact relationships could be used for further study of contact stresses at the full tyre/road interface.