Void in Plastic parts

[adevadkar]

Hello Guys,

I am working on parts which having some thick cross section areas present in parts,
Ai got the large amount of Avg Volumetric shrinkage. (8-10%), There are chances of getting voids inside the parts at thick sections, can we detect voids inside the parts, is there any way to represent this in Moldflow results other than volumetric shrinkage? 

[mason.myers · Accepted solution]

Hello @adevadkar ,

I am co-presenting this topic at our Moldflow Summit on April 16-17th.  I have a script  to calculate voids but I would like to wait until we present to share with the community.

Some of us at Autodesk have a theory that increasing volumetric shrinkage could lead to voids.  Assuming your run a Fill+Pack, you can then create a new Calculated Plot.  I title the Plot "Voids" and select Volumetric Shrinkage, last time stamp and then Volumetric Shrinkage first time stamp.  Once the plot is created, I go to plot properties - Scaling and choose Specified.  I then set the Min value to be ~64% of the Max value.  This 64% can be adjusted up if needed.  Finally, I deselect Extended Color.  I have seen good results comparing this method to CT scans of actual parts.

Mason

[PascalGosset]

Hi simulators,

This week, I met this problem once again.
7 years ago (my goodness!) I posted an answer about it.
I got interresting repplies, especially from Hanno van Raalte, but nothing definitive.
You can read my post here:
https://forums.autodesk.com/t5/moldflow-insight-forum/predict-the-voids/m-p/6974964

Mason,

I tried to test your method on the little hook I studed this week.
With the thickest version, it predicts a void. It is what I expected.
But with the thinner version, it predicts also a void. I hope it won't be the case.
  

[mason.myers]

Hello @PascalGosset ,

Thank you for the feedback.  I agree, I doubt you will see a void in that thinner area.  My intent was to use something similar to the air trap plot with the varying levels of severity.  For the voids, I would focus more on the red areas as a higher probability.  Again, this was more of an awareness tool however we have seen good success comparing this plot to CT scans on actual parts.

Mason