https://mechcalc.net/blog/en/tags/structural-mechanics/ Recent content in Structural Mechanics on MechCalc how-to Guide https://mechcalc.net/blog/og-default.png https://mechcalc.net/blog/og-default.png Hugo en Mon, 13 Apr 2026 21:15:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-04-bearing-pressure/ Mon, 13 Apr 2026 21:15:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-04-bearing-pressure/ 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 — and gives engineering measures such as controlling the limiting surface pressure and enlarging the bearing area. https://mechcalc.net/blog/en/posts/bolt-preselection-02-reduction-factors/ Mon, 13 Apr 2026 18:00:00 +0200 https://mechcalc.net/blog/en/posts/bolt-preselection-02-reduction-factors/ Where does the reduction factor κ in bolt pre-selection come from? Starting from the two-way stress state where axial tensile stress and torsional shear stress combine during tightening, this article uses the von Mises yield criterion to derive the definition, formula and engineering values of κ, explaining how thread friction acts like an 'invisible tax' that cuts the bolt's axial load capacity, and why it appears in the denominator of the Kübler equation.