Estimation of normal contact stiffness for different contact pairs: Experiments and numerical approach

Modelling of frictional contact systems with high accuracy needs the knowledge of several contact parameters that are mainly related to the properties of the contact interfaces. While the interface parameters cannot be directly obtained by performing local measurements, the values estimated by means of analytical/numerical models are not reliable to describe the contact behavior, which affects in a prominent way the complex contact phenomena. This work presents a newer approach for identifying reliable values of the normal contact stiffness between rough surfaces as a function of contact pressure, surface roughness and materials. The combination of dynamic experimental tests, on a dedicated set-up, with finite element modelling allowed for an indirect determination of the normal stiffness at the contact.