Overlap of parts in prepomax v2.2.0

1

I have been following a tutorial by an active member on these forums, HOWEVER, the ONLY difference i made was i exported the supplied step file to a stl file. I did that for a good reason.

Everything went smoothly except the contact pairs situation in prepomax. I had to manually select master/slave faces that contacted each other because the search function was not working, probably due to the idea that it was ONE single part rather than 2.

Anyway, after running the analysis, the links are now overlapping for some odd reason.

Any help would be excellent.

Thanks

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2

Looks like it’s due to low contact stiffness. There’ll always be some penetration so you have to decide how much is acceptable.

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3

that was not covered in the tutorial, so i wonder how they did not get this issue. Where do i find this option for contact stiffness? thanks : )

4

here is the tutorial i am following.

PrePoMax (CalculiX FEA) - Tutorial 14 - Chain links - YouTube

5

Looks like the tutorial’s using hard contact which means linear but CCX chooses the contact stiffness. I never knew CCX had that. Maybe it’s OK though?

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6

i do not know haha. something is causing mine to bug out haha

7

Is the scale right? STL has no units. Is the stress right?

8

i set the file to mm and the force of 200 newtons is correct, but the value for stresses im not sure are correct due to the “bug”

SInce im new to prepomax, how would i check the length of the part or at leas see if its the correct dims?

thanks. Ill answer back when i can,

9

plot it with True Scale, I can’t see the Deformation Scale factor in the picture you posted. Should be 1.0, otherwise you can’t see actual contact situation.

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10

The black and white scale at the bottom of your screenshot shows the size.

11

In such cases you should always check the deformation scale factor first and set it to 1 or true scale to see the actual, not scaled deformation.

2 Likes
12

indeed, this scale bars should be invisible in post-processor to avoid misunderstanding.

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13

found the “true scale” option

Now i need to see why my values are twice what they should be

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