Problem with gear simulation

apuisto · September 27, 2022, 6:42pm

I have this model and cannot get it working. https://www.simscale.com/workbench/?pid=1654194418588198455&mi=spec%3A7c7b03cf-99c1-4399-bfbd-53b024616ff1%2Cservice%3ASIMULATION%2Cstrategy%3A2
Error I get is below.
The residual extrapolation between time-instant 0.0 and 0.001 failed. This could be due to e.g. the lack of a load increment at the given instant. The following is recommended:

review your boundary conditions, e.g. check that there is a load increment between the time instants
change the convergence criteria from relative to absolute.

ggiraldof · September 27, 2022, 8:14pm

Hi there, and thanks for using the forum!

I just finished reviewing your setup, and it is not completely clear to me what you are trying to achieve.

Could you please provide some context, so we can help you to get the right setup?

apuisto · September 28, 2022, 7:56am

Hi, i need to analyze how much torque this gear set up can handle. smaller one is master gear (torque comes in) and bigger is slave (torgue comes out). I know setup is not correct but I did not find example how it should be.

SBlock · September 28, 2022, 9:02am

Hello

If you are just interested in the load of the gears, you can have a setup like this.

Fixed Support
Physical Contact as you have already set up
Remote Force
Hinge boundary condition.

For the hinge boundary condition and the remote force please ensure that the reference point is set to the origin of the axis of the drive gear. (the values i have here are just eyeballed, please measure them in your CAD Software)

Also, I would suggest ramping up the torque using a table input.
This will gradually ramp up the load stabilizing the simulation.

To achieve this also set the simulation interval to 1 second.

Best regards
Sebastian

apuisto · September 28, 2022, 11:16am

Thanks, everything else should now be ok. what is missing is 1. Hinge boundary condition. For some reason I cannot find it under boundary connections

SBlock · September 28, 2022, 11:34am

Hello apuisto

you should be able to find the hinge boundary constraint here:

More information on this boundary constraint can be found here:

best regards
Sebastian

apuisto · September 28, 2022, 11:51am

I have only these

SBlock · September 29, 2022, 7:16am

Hello apuisto

This feature is very new to SimScale. It seems like it’s not fully deployed to everybody.

Please use the remote displacement to set up the boundary condition.

Best regards
Sebastian

apuisto · September 30, 2022, 9:55am

Hi,
thanks, after using remote displacement to set up the boundary condition I start to get these errors. tried to do some changes but no help Latest simulation is this https://www.simscale.com/workbench/?pid=1045158511123030526&mi=run%3A39%2Csimulation%3A2&mt=SIMULATION_RUN

- Newton convergence could not be reached. Possible options to prevent that behavior: Update the tangent matrix more often, increase the maximum number of iterations, use automatic timestepping or decrease the timestep. Learn more.

SBlock · September 30, 2022, 10:06am

Hello apuisto,

seems like you have forgotten to set the physical contact for the simulation.

Please ensure to select the right faces for the contact definition based on the right-hand rule and definition of your toruqe

apuisto · October 3, 2022, 7:57pm

Still no luck with this. I think everything is correct ( excep instead of remote displacement boundary I have rotating motion since it failed with remote displacement)
This is my final try https://www.simscale.com/workbench/?pid=1045158511123030526&rru=22bfcbf1-1420-4eb6-98d1-4e98bef02e52&ci=5eb051e3-045f-4fb1-86cd-46c66b952a46&mt=SIMULATION_RESULT&ct=SOLUTION_FIELD and now I am getting this:
“The specified maximum runtime of the job was exceeded. The simulation run was stopped and potential intermediate results were restored. You can try to increase the maximum runtime in the simulation control section and start a new run to enable a complete simulation run.” What I need to change in order to get this right and calculated without timeout.

SBlock · October 4, 2022, 7:34am

Hello apuisto,

I think the issue is that you have set the remote displacement boundary condition fix to all degrees of freedom.

For your case, the rotation on the y-axis should be free.

Also Mz should be set to 0

I have also shared a project with my setup so you can look at it.

Best regards
Sebastian