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Non linear analysis not converged

Hello,

I am running a non linear analysis and when i run it, i don´t know why it stay calculating a lot of time and finally it doesn´t converge so the it failed and post the next message.

* ERROR # 4966 ***Minimum time increment reached,analysis aborted.

Please can someone help me with this problem i have tried some thing but i don´t know how to solve it. I linked the file here.

Ensayo de Traccion.hm

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Chayan

Hi Juan,

Have you checked the .out file error and warning messages? OptiStruct will typically provide you with details of the error in the out file.

Adriano_Koga

you might also take a look at these general tips for OS NL problems.

https://community.altair.com/community?id=community_blog&sys_id=538764ab1b3790d4a5f742eddc4bcba4

Juan Torres

I have read them but, i am new using hyperworks and i don´t undertand it very well i have followed some tips of the OS NL problem but i don´t fing the solution. I have checked the .out file error warning messages and there wasn´t, the only think i have seen is the error:

* ERROR # 4966 ***Minimum time increment reached,analysis aborted.

The file is this because i have done some corrections due to the OS NL problems.

Ensayo de Traccion.hm

PaulAltair

I have read them but, i am new using hyperworks and i don´t undertand it very well i have followed some tips of the OS NL problem but i don´t fing the solution. I have checked the .out file error warning messages and there wasn´t, the only think i have seen is the error:

* ERROR # 4966 ***Minimum time increment reached,analysis aborted.

The file is this because i have done some corrections due to the OS NL problems.

Had a quick look, your set up of 33 consecutive cases is a bit unconventional (if you just want to see what the run is doing you can use NLOUT and run a single case). But the main issue is that the level of non-linearity is way beyond the bounds of what you can model successfully think, in the first of your cases you are asking for nearly 100% strain? (extension of 0.1mm?, total test piece free length is 0.11mm?) By then the elements at the centre have necked/stretched already. Are your units correct? by the time you reach the 33rd case you are requesting extension of 17mm against 0.11mm starting length (approx 15400%) that doesn't really make sense?

Adriano_Koga

I have read them but, i am new using hyperworks and i don´t undertand it very well i have followed some tips of the OS NL problem but i don´t fing the solution. I have checked the .out file error warning messages and there wasn´t, the only think i have seen is the error:

* ERROR # 4966 ***Minimum time increment reached,analysis aborted.

The file is this because i have done some corrections due to the OS NL problems.

share the .out file as well.

Any particular reason to apply the enforced displacement in multiple loadsteps?

You could apply it in a single loadcase.

PaulAltair

share the .out file as well.

Any particular reason to apply the enforced displacement in multiple loadsteps?

You could apply it in a single loadcase.

out file attached

Tensile.out

Juan Torres

Thanks you so much, i have checked and now it runs good. I have some problems with the units because i am new using hypermesh and I don´t know why when i export the files of inspire mold analysis and then import the c2mRun_fiber_main.fem on HyperWorks the measures changes.

In the next images you can see the real measures on injection molding.

And now how I import the mesh of the injection molding analysis result on HyperWorks.

As you can see the measurements changes in the import, how can i made them stay with the same magnitude? Because I need the file in the right measurements for the nexts steps.

PaulAltair

Thanks you so much, i have checked and now it runs good. I have some problems with the units because i am new using hypermesh and I don´t know why when i export the files of inspire mold analysis and then import the c2mRun_fiber_main.fem on HyperWorks the measures changes.

In the next images you can see the real measures on injection molding.

And now how I import the mesh of the injection molding analysis result on HyperWorks.

As you can see the measurements changes in the import, how can i made them stay with the same magnitude? Because I need the file in the right measurements for the nexts steps.

Inspire Mold uses Meters by default as its model units (even if you change the display units) and if not changed it will export in meters, hence the import length in HM being 0.163 rather than 163, you can change the unit system in inspire mold in preferences.

Juan Torres

I am looking for units in preferences but i can´t found them.

I followed those steps that are in the help page of inspire mold but i don´t find the units on preferences, maybe in the 2022 version it changes?

Community-Pasted-Attachment-1651666837959.jpg

PaulAltair

I am looking for units in preferences but i can´t found them.

I followed those steps that are in the help page of inspire mold but i don´t find the units on preferences, maybe in the 2022 version it changes?

What version are you using? I don't have an older version installed but the help had the same instructions as far back as 2020.1 which is the oldest copy I have available, image below is from my 2022 Inspire install (I don't have Mold installed currently)

Juan Torres

I have installed inspire 2022 and inspire mold 2022, the preferences of the last image i posted was the preferences of inspire mold, in inspire 2022 i have the same preference menu than you, i have change the units to mm in inspire but in inspire mold it still being the same in meters.

PaulAltair

I have installed inspire 2022 and inspire mold 2022, the preferences of the last image i posted was the preferences of inspire mold, in inspire 2022 i have the same preference menu than you, i have change the units to mm in inspire but in inspire mold it still being the same in meters.

Ok, not sure then.

To workaround, you can easily scale the imported model in HM, but not sure what your model from Inspire contains? If it has material data you would need to modify that too.

Another approach would be to define the model in MKS units in inspire, (i.e. define it as 0.16m dimension etc) that way the incoming file being in meters would be correct?

It might be worth posting this in the Inspire (Mold) forum too to see if there is any other method as this now seems to be an Inspire Mold issue rather than OptiStruct?

Juan Torres

Okay, thanks you so much for your faster answers, i will try what you are saying and also i will post it in the Inspire mold forum.