Composite tube crush

Altair Forum User

Hi! I'm doing composite tube crush simulation on radioss. I'm crushing composite tube with rigid body with initial velocity and mass of 500kg with gravity implemented. In the composite tube, top row of elements have less composite plies than rest of the tube so that crushing would start at the tip of the tube. My problem is that despite of thinner top of the tube, it breaks in half at bottom of the tube. How I can fix this problem?

 

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Altair Forum User

I found solution to this problem if anyone encounters same situation. I had two problems with my model. Firstly, I did make mistake in material parameters. Tensile failure strains were too small so my material was more brittle than what it should have been. Secondly, I used BCs at the bottom of the tube to keep it in place. However, this created shockwaves in the tube when rigid wall hit to tube. These shockwaves created tension to tube and that broke the tube at bottom. What I did was to remove Tz BC and attach tube on top of steel plate which acted as damper.