Kontaktmekanik

Kontaktmekanik, often translated as contact mechanics, is a field within tribology and solid mechanics that studies how bodies come into contact and how contact forces, deformations, and surface phenomena develop at interfaces. The central challenge is to relate external loads to contact pressure distributions, contact areas, and resulting displacements, while accounting for material properties and surface topography.

Classical theories begin with Hertzian contact, which describes elastic contact between smooth bodies (such as spheres, cylinders, or flat punches) without adhesion. For situations where surface forces are important, adhesion is incorporated through models such as the Johnson-Kendall-Roberts (JKR) and the Derjaguin-Menell-Krejci (DMT) theories. In tangential loading, Mindlin's solutions describe partial slip and stick behavior under friction. The friction law most commonly used is Coulomb’s law, though more sophisticated rate- and state-dependent models are also applied in tribology.

Rough surfaces are ubiquitous in engineering and require statistical or multiscale descriptions. The Greenwood-Williamson model treats roughness as an array of asperities, while more recent approaches, including Persson’s theory, aim to link real contact area and pressure distributions to roughness spectra across scales.

Analytical solutions exist for idealized geometries; in practice, numerical methods such as finite element analysis (FEM) and boundary element methods (BEM) are used to handle complex geometries, elastic-plastic material responses, adhesion, temperature, and lubrication effects. Applications span gears, bearings, seals, tires, MEMS devices, and electronic packaging, where contact mechanics informs wear prediction, fatigue life, and reliability.

Ongoing work in kontaktmekanik addresses multiscale phenomena, adhesive contacts, thermal contact resistance, and the interaction between roughness, lubrication, and surface treatments to improve interface performance.