The Mass With Stop And Friction component models a mass sliding with friction on a fixed surface and with perfectly plastic stops in both directions. A finite state machine ensures that the mass transitions correctly from stuck to sliding.

The distance between the left and right flanges is given by parameter $L$. The coordinate $s$  corresponds to the midpoint of the two flanges.

$L\=s_a-s_{b}s\=\frac{1}{2}\left(s_a\+s_b\right)v\=\stackrel{\.}{s}a\=\stackrel{\.}{v}$

With the mass sliding in the positive direction, the frictional force is

$f\=F_{\mathrm{Coulomb}}\+F_{\mathrm{prop}}v\+F_{\mathrm{Stribeck}}\exp \left(-f_{\exp }v\right)$

When the velocity goes to zero, the mass becomes stuck. It resumes sliding when the magnitude of the applied force exceeds the maximum static friction force,

$f_0\=F_{\mathrm{Coulomb}}\+F_{\mathrm{Stribeck}}$

The component described in this topic is from the Modelica Standard Library. To view the original documentation, which includes author and copyright information, click here.