Unable able to get optimized structure even tho it showes optimization is converged.

pranav_21387

Trying to optimize cantilever beam (it has both design part and nondesign) by giving following variables:

1. topology for (design part)

2.optimization responses- mass  and frequency

3. constraints- frequency (upperbound 200Hz)

4.objective- minimizing mass.

after running optistruct , it is showing that "OPTIMIZATION HAS CONVERGED. FEASIBLE DESIGN (ALL CONSTRAINTS SATISFIED)"

but in optimization summary ELEM/GRID ID is 0 and element density is as shown below :

 

 

can anyone tell me whats the issue? also attached output file . 

cantilever (1).out

cantilever (1)_s1.h3d

PaulAltair

If your only constraint is on max frequency, and your objective is to minimize mass, then I think it has achieved your request by removing all the designable material, you'll need some non-designable material or some other constraint (e.g. on minimum volume fraction) as well to force a sensible optimisation