Investigations of the influence of geometrical irregularities and roughness on the normal contact stiffness of joints

Abstract

AbstractConducting experiments is necessary to determine the normal contact stiffness of rough surfaces. In compression tests the interface of specimen pairs is loaded in normal direction and the deflection is measured by extensometers with strain gages. The results can be used for example to describe the contact behaviour of joints in finite element analyses. It is shown that geometrical irregularities which are superposed by the surface roughness have a large influence on the elastic deformation of a joint and on the determination of the contact stiffness. They can be characterized by a skewed and a waved form of the surface with wavelengths which are larger than the surface roughness. In the experimental setup several different surfaces are compressed. In addition, the influence of the size of the contact area on the deformation of a joint is analysed. The results of the normal contact tests are compared with numerical simulations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)