title: on the using of MassWithStopAndFriction and hard stops in OpenModelica
body: <p>I have a question about hard stops in Modelica.Mechanics.Translational.Components.MassWithStopAndFriction. 
  As I can understand mass should not move outside interval (smin, smax) 
  But it actually does in my example that I include here: </p>
  
  <pre><code>model ActuatorMechanics 
    Modelica.Mechanics.Translational.Sources.Force force; 
    Modelica.Mechanics.Translational.Components.MassWithStopAndFriction mass(m=1,F_prop=0,F_Coulomb=10, smax=0.1, smin=0, L=0.01); 
    Modelica.Mechanics.Translational.Components.Spring spring(c=1000); 
    Modelica.Mechanics.Translational.Components.Fixed fixed; 
    Modelica.Mechanics.Translational.Sensors.PositionSensor sens_pos; 
  equation 
    connect(force.flange, mass.flange_a); 
    connect(mass.flange_b, spring.flange_a); 
    connect(spring.flange_b, fixed.flange); 
    connect(sens_pos.flange, mass.flange_a); 
    force.f = 100; 
  end ActuatorMechanics; 
  
  simulate(ActuatorMechanics)
  plot(mass.flange_a.s)
  </code></pre>
  
  <p>Am I doing something wrong?</p>