Did I setup my M33_FOAM_PLAS correctly?
Hi everyone,
I just finished running a simulation of a FSAE impact attenuator but the results didn't seem to match the test we did in real life. The 4130 steel tubes didn't bend very much and the foam compressed a lot more than it did in real life. I think I didn't setup the foam material correctly but I am not sure.
Did I set my simulation up correctly?
Here is the setup file and video of the results.
Thanks in advance.
Answers
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Hi,
There are initial penetrations; check and resolve using:
-in Hypercrash: Quality>Check all Solver Contact Interfaces
-in Hypermesh: Tool>penetration checkThe issue is due to the yield stress vs. volumetric strain curve. Because the curve has a negative last slope Radioss extrapolates negative stress, which is not valid (The input stress should be positive for both tension and compression). As a workaround, define an additional curve segment with a zero or positive slope.
Yield stress vs. volumetric strain curve should look like:
<?xml version="1.0" encoding="UTF-8"?>
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Hi Simon,
I'm still new to hypermesh and I don't understand a few things.
How does radioss use the the yield stress vs volumetric strain curve and youngs modulus? Wouldn't youngs modulus be dependent on the slope of stress vs strain curve?0 -
This material law initially follows the Maxwell-Kelvin-Voight viscoelastic model until it intersects the defined yield curve, which limits the visco-elastic stress in tension and compression.
For more details refer to the attached documentation (from Radioss help):
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