Wili unfortunately I cant give specific code because of my thesis' confidentiality however I can describe the following:

My model comprises of the following components:

-world coordinate system                                                                                       ((connected to prismatic joint))
-prismatic joint (allowing movement only in x axis)                                           ((connected with bottom frame of body cylinder))
with flange axis enabled, having a parallel spring damper connected on top.

-body cylinder                                                                    ((connected on its top frame with  loading component))

-loading component for external load application, containing the velocity of the cylinder in the form of:
__________________________________________________________________________________________-
(A)=(constant(<-0.01-0.05) - cylinder_velocity)*constant

if A <0 then
B=0
elseif A >=0 and A <= 2 then
B= constant + constant*A^2- constant*A^3....
else
B=constant
end if;
Load=B*constant;
____________________________________________________________________________________________

The above load model is connected to the main model, where there is the  equation   cylinder_velocity=der(prismatic.s) or prismatic.v[1]  and this is how the coupling happens.
If you have any suggestions of what kind of guard or function i should apply and where, it is more than welcome.
With euler it gets solved but it is really sensitive to the interval length and create many state events.
I dont yet know if this is normal or not(the state events)  for the specific modeling.

Thanks

Willi thank you very much for your reply.

I will try to post some something later today, so I can give you  a better impression .

Thanks

Good day

I am currently experiencing problems during simulations. I have set up a single degree of freedom (linear spring-damper-rigid body cylinder) system with movement only in horizontal axis, experiencing an external force excitation which is however coupled with the body cylinder, meaning that the loading model contains a velocity that is the der(s) of the bodycylinder.
My damper,spring,cylinder all have input properties, so I apply an initial excitation and wait for Newton's law to be validated.
The external force is not continuous, it switches on and off . When my external force is totally uncoupled from the cylinder's movement the model simulates fine and the results are ok.
Whenever the force is coupled with the cylinder velocity, simulation is stuck or finishes but shows unnatural behavior( extremely high force and acceleration-Zeno). My guess is that when der(s) switches from positive to negative, the discontinuity causes noise to the algorithm.
I have tried some things (noEvent,smooth,reinit etc) but nothing happens.
If someone has a better idea, I d love to hear it out.

Thank you.