Optimization of contact surfaces in assembly in the presence of form defects and interference

Shrink-fit assembly is one of the most important mechanical assembly methods. It has been used for many years because it is economical due to it needing only two components an axis and a hub, as the outer diameter of the axis is greater than the inner diameter of the hub and the difference between them is the “interference.” The shrink-fit assembly is used in several fields such as the manufacture of aircraft, cars, and connecting oil and gas pipelines. Assembly is achieved either by heating the hub and cooling the axis or by force. When assembling, contact pressure is formed on the contact area between the axis and the hub. Usually, the contact area is considered perfect, but in reality, it contains defects that vary in amplitude and number. In this article, we study the role of the form defect and interference in the 3D assembly by studying its effect on the extraction force and assembly coherence, with use numerical simulation to confirm this. Component separation experiment was applied to validate the simulation results.