Why I can't constraint the radial displacement in a periodic model?

loveHL · May 21, 2014, 00:30

My software is star ccm+ 7.04.
I new a periodic structure model, which is very simple:
111.PNG
The Models are as follows:
222.PNG
and the Boundaries are set like this:
333.PNG
I have set the axis.
However, when running the simulation, it is surprising that the displacement in the radial direction keeps increasing.
4444.PNG

It seams that the periodic boundary did't work!

Who can help me? I have confused the problem for several days!

me3840 · May 21, 2014, 10:42

Can you describe the problem you're trying to solve in detail?

loveHL · May 21, 2014, 12:43

The model is just a piece of solid ring, whose degree is 30° and material is graphite. on the bottom, the Stress/Displacement method is normal displacement, on the inner, the pressure is 0.2MPa, and others are free.

The reason why I modeled the simple model is that I just want to verify whether the periodic boundary condition constraints displacement in the radial and tangential direction. I found that the periodic boundary condition didn't work when I used it in other models.

May 21, 2014, 00:30	Why I can't constraint the radial displacement in a periodic model?	#1
loveHL New Member Join Date: Apr 2014 Posts: 6 Rep Power: 12	My software is star ccm+ 7.04. I new a periodic structure model, which is very simple: 111.PNG The Models are as follows: 222.PNG and the Boundaries are set like this: 333.PNG I have set the axis. However, when running the simulation, it is surprising that the displacement in the radial direction keeps increasing. 4444.PNG It seams that the periodic boundary did't work! Who can help me? I have confused the problem for several days!

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May 21, 2014, 10:42		#2
me3840 Senior Member Join Date: Nov 2010 Location: USA Posts: 1,232 Rep Power: 25	Can you describe the problem you're trying to solve in detail?

May 21, 2014, 12:43		#3
loveHL New Member Join Date: Apr 2014 Posts: 6 Rep Power: 12	The model is just a piece of solid ring, whose degree is 30° and material is graphite. on the bottom, the Stress/Displacement method is normal displacement, on the inner, the pressure is 0.2MPa, and others are free. The reason why I modeled the simple model is that I just want to verify whether the periodic boundary condition constraints displacement in the radial and tangential direction. I found that the periodic boundary condition didn't work when I used it in other models.