*** ERROR # 583 *** Missing objective, DESGLB and DESSUB data must be used together with an objective function defined by DESOBJ, MINMAX, or MAXMIN.

Pablo de Castro Cruz

I am a beginner in the composite optimization and I follow all the steps from the tutorial to do this optimization, but I got the same error and I don`t know why.

If there is anyone that could help me I would be so gratefull because I had been trying to find the solution so many days and I didn`t get anything.

If there is necessary I add the model file.

Thank you.

FreeSizing_freesizing.mvw

RobHoglund

Hi Pablo,

OptiStruct uses the "DRCO" method to define an optimization problem.  This stands for design variable, responses, constraints, and objective that you generally need.  

The error message indicates you're missing an objective, so please go ahead and make sure you have that defined in the model as well as the other steps in the DRCO.  For example you might need to select a 'mass' response as the objective to minimize.  The objective is defined in a similar manner to the responses and constraints with a separate icon.  If you're using HyperMesh 2023, it looks like this:

Thanks,

Rob H.