OPTIMIZATION MESSAGE- AUTODESK SIMULATION

[Anonymous]

Hi, 

I am simulation using the "optimization" analysis trying to replicate the analysis from this paper :

Design Optimization of a Car-Truck Stand

http://www.asee.org/public/conferences/8/papers/3018/view

I have defined the beams as DV without problems, then I define a Objective/Constraint with Max Stress with a Upperlimit of 250MPa (A-36), and when I have tried to simulate, appears this message at Design Optimization Dialog Box

# of Design Variable = 3 # of Performance = 1
Optimization Method = 1 MaxIter = 37
MaxObjChange = 0.010000

** Design Variables **

Design Part# Property Lower Limit Current Value Upper Limit

** AISC Beam Section Type should be same for %d th design list !!

It seems something about the asigning beam section, any idea?

Thanks