NX NASTRAN Topology Optimization

[iprestes]

Hello,



I am a new user of the Topology Optimization NX Nastran (version 12.0).

I did the Siemens tutorials and tried to reproduce the same steps for another geometry that I created. However, the optimized geometry's displacement is way too high. It results in 25 mm, although I set a constraint for it to be not hight than 3 mm.

Also the material density results make no sense: if I use a Lower Bound equivalent to 0.04 some random meshes (which are not even connected) appear; if I set the lower bound to 0.03, the whole geometry appears.





Does anyone know what is happening?



Thanks!

 

[TG_eng]

What's the displacement in Design Cycle 1?

 

[iprestes]

0.514 mm against 0.435mm on the original design.
However, I get the same problem with the material density. With a lower bound of 0.81, there is no connection between the parts; with a lower bound of 0.79, I get the same geometry as the original. With 0.8, I get a kind of a porous material, but doesn't make any sense.