The upper half of the VDI 2230 calculation chain R1βR6 explained: the tightening factor Ξ±A, the three sources of the minimum clamping force FKerf, the choice of force-ratio Ξ¦ formula, preload loss (embedding + thermal expansion), and the derivation of the minimum and maximum assembly preload.
Why does a bolted joint fail as a whole when the surface is only crushed a tiny bit? This article uses the model of a 'stretched rubber band clamping a sponge' to see through the mechanics of the bearing-pressure check: from microscopic peak crushing and macroscopic embedding (Setzen), to the elastic recoil that causes an irreversible loss of preload (clamping force), to the chain failure of loosening and fatigue fracture β and gives engineering measures such as controlling the limiting surface pressure and enlarging the bearing area.