Calculation and Experimental Study of the Real Contact Area, Contact Pressure, and Coefficient of Friction

30.09.2026

The study investigates the formation of the real area of contact and the corresponding contact pressure during the tribological interaction of rough surfaces. Particular attention is given to the distinction between the nominal area, contour area, and real area of direct contact, taking into account the waviness and roughness of the surface profile. A calculation approach based on the geometric and statistical characteristics of the surface microrelief is used to estimate the transition from the nominal contact area to the actual areas involved in load transfer. The contact pressure in the zones of direct interaction is evaluated considering the deformation of surface asperities and their mechanical characteristics. The calculated parameters of the real contact are compared with the experimental characteristics obtained during tribological testing. The analysis demonstrates the importance of considering the actual contact conditions when interpreting tribological test results and evaluating the stress state of contacting surfaces. The proposed approach provides a basis for a more physically justified assessment of contact interaction and the subsequent analysis of friction and wear processes.

real contact area; nominal contact area; contact pressure; surface roughness; waviness; asperities; friction; wear; tribological interaction.