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Error: Failed to find time step so that given tolerances are satisfied.

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Hello Everybody,

I'm using a 2D structural mechanics module.
The geometry is a simple square.
The material is Viscoelastic.
I applied boundary conditions on the square.
I chose the Time Dependent solver --> Quasi-static transient.

The boundary conditions I defined are dependent on a new parameter.
I defined this new parameter as a function of the timestep (as a function of time...).
As a result I received the following error:

Error: time 0:
Failed to find time step so that given tolerances are satisfied.
Last time step is not converged.

... I tried changing the time steps and the tolerances - but no luck there!
Does anyone have an idea?

I would very much appreciate your help!
Thank you :)
Tal

2 Replies Last Post 13 mar 2012, 17:14 GMT-4

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Posted: 1 decade ago 1 nov 2010, 12:55 GMT-4
Make sure you change the time step actually. Sometimes even you feel you make changes, COMSOL still runs based on previous setting.You may try deleting all the solvers and rerun again.
Make sure you change the time step actually. Sometimes even you feel you make changes, COMSOL still runs based on previous setting.You may try deleting all the solvers and rerun again.

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Posted: 1 decade ago 13 mar 2012, 17:14 GMT-4
I faced this kind of problem by a similar analysis, except that it was a Structural Mechanics3D analysis, it was on a square bar where this was subjected to a flexion condition, first i placed the boundary conditions and also defined a rigid conector and on this a flexion moment, so i ran the simulator and i got the same error: "Failed to find time step so that given tolerances are satisfied." not even finished to calculate the first step. I tried many times changing on study setting the times, range and even the method. So after i decided to change the flexion moment applied on a rigid conector by an equivalent force using a boundary load appliying it where it was initially applied the rigid conector and by this way i got the desired results, i also tried changing the times, getting the same good results.

I know you're running a 2D model but hopefully this can help you

Best Regards.
I faced this kind of problem by a similar analysis, except that it was a Structural Mechanics3D analysis, it was on a square bar where this was subjected to a flexion condition, first i placed the boundary conditions and also defined a rigid conector and on this a flexion moment, so i ran the simulator and i got the same error: "Failed to find time step so that given tolerances are satisfied." not even finished to calculate the first step. I tried many times changing on study setting the times, range and even the method. So after i decided to change the flexion moment applied on a rigid conector by an equivalent force using a boundary load appliying it where it was initially applied the rigid conector and by this way i got the desired results, i also tried changing the times, getting the same good results. I know you're running a 2D model but hopefully this can help you Best Regards.

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