topic Re: How to change the compressibility of a material? in Moldflow Insight Forum

How to change the compressibility of a material?

PascalGosset — Mon, 05 Dec 2016 10:50:42 GMT

Sometimes, I compare the simulated injection pressure to the real one.

Often, I notice an important difference between them.

It seems the error is done mainly in the runners.

I think, it is because the compressibility of plastics is underestimated.

So: is it possible to change the compressibility of materials and how?

Re: How to change the compressibility of a material?

ErikFoltz5821 — Mon, 05 Dec 2016 13:45:20 GMT

Hello Pascal,

I believe to account for compressibility of the polymer, you would need to alter the PvT data. Additionally, in a 3D model you could define your own viscosity model.

However, I think you are also asking about the response of the polymer melt to a change in forces, or the visco-elasticity of the material. I don't believe this has been commercially released yet. It might be in beta?

Erik

Re: How to change the compressibility of a material?

PascalGosset — Mon, 05 Dec 2016 14:47:35 GMT

Hello Erik,

I hope you are fine.

Thanks for your answer.

It's possible I'll ask you more precise questions once I'll have time to work seriously on this problem.

Re: How to change the compressibility of a material?

Javier.Jubierre — Fri, 09 Dec 2016 13:40:22 GMT

Hi @PascalGosset

Actually this point was discussed on this year AU. One of the suggestions was to tweak the value D3 of the viscosity model.

This is the link to the class on-line (SIM22068: “The pursuit of accuracy” A simulation story with Autodesk Moldflow).

I hope it helps!

Cheers,

Javier

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Re: How to change the compressibility of a material?

PascalGosset — Sun, 18 Dec 2016 21:58:31 GMT

Thanks Javier.

Erik Foltz showed also an interesting work on this item at AU2012:

http://au.autodesk.com/au-online/classes-on-demand/class-catalog/2014/moldflow-insight/sm4977-p#chapter=0