Reply To: Help with choosing the simualtion type: rigid body motion

[adamkovacs1126]

Hi Peter,

Thank you very much for your quick answer! 

I used SolidWorks for creating the model but I was told that Ansys will be a better tool for simulation.

Following your advice I tried the Rigid Body Simulation, I applied Ground to Body Revolute Joints at the center of the rotating parts to make them fixed against translational motion but free to rotate, Fixed Joints for keeping necessary parts together such as the pallets and the pallet fork and Frictional Sliding contact between the following parts:

- escape wheel and pallets

- pallet fork and banking pins

- pallet fork and jewel pin

I have not designed the spring yet because first I just wanted to see one half-cycle of the oscillation i.e. how the tooth of the escape wheel first unlocks from the first pallet and then locks again on the other pallet. For this, I created a joint moment turning the escape wheel representing the main spring and another joint moment turning the balance wheel-roller-jewel pin assembly representing the hairspring. 

The simulation fails to solve completely, it stops just after the tooth of the escape wheel escapes the first pallet and starts sliding on it. To see the animation, I included it in a GIF file, if you can't see it, you can click on the following link:

http://gifmaker.me/PlayGIFAnimation.php?folder=2018072321hTlW6EcVNAvkKgFsXUThwV&file=output_AUHNq8.gif

I collected the following various error messages from the solver:

    Error: state inconsistency, receive no contact point for an active contact pair. Try reducing the time step
    State Inconsistency for the contact: Shock detected without contact point
    State inconsistency at time 6.858711e-05. The solution has been restarted.
    Contact "Forced Frictional Sliding - Jewel Pin-1 To Pallet Fork-1" Received 8 contact points
    Error: state inconsistency, receive no contact point for an active contact pair. Try reducing the time step
    State inconsistency at time 2.316455e-04. The solution has been restarted.

Contact "Forced Frictional Sliding - Jewel Pin-1 To Pallet Fork-1" Received 7 contact points
    Stopped Forced Frictional Sliding - Jewel Pin-1 To Pallet Fork-1 at 0.000268116
    Murty's algorithm reached maximum number of iterations: 49
    Last 3 minimal values are -4.865388e+05 -1.530893e+10 -4.865388e+05
    Murty by Factorization algorithm failed
    Trying PSOR
    PSOR algorithm reached maximum number of iterations: 49
    Initial residual 6.461609e+05 Last 3 residual values are 3.738246e+03 3.738250e+03 3.738253e+03
    PSOR algorithm failed
    Trying Lemke
    Lemke algorithm failed
    Trying Lemke
    Enforce RHS may lead to inaccurate solutions, carefully check results.
    Lemke algorithm failed
    Trying Write LCP matrices
    Write LCP matrices algorithm failed
    None of the LCP solvers succeeded, Abort computation.

    No set of active contact stops can satisfy all the constraint equations. Solve cannot proceed

 Solve failed
    Error found at time 2.844257e-04

    Solution terminated before normal completion

Do you have any idea about what I can do to make the simulation solve the problem completely?

Thank you very much in advance,

Kind regards, 

Adam