[Ipopt] ipopt in structural optimization

[Ruhollah Tavakoli]

Peter

Look at SICON 06 paper of Martin Burger (http://dx.doi.org/10.1137/05062723X),
He used IPOPT to solve discretized form of structural topology optimization.

In my experience, IPOPT is *very* robust for such problems, but is very
expensive in contrast to e.g. OC or MMA.

Cheers

RT

On Wed, May 27, 2009 at 9:06 AM, Clausen Peter M. <
peter.clausen at fe-design.de> wrote:

> Hello
>
> I am working at FE-DESIGN GmbH (www.fe-design.com) and our
> program TOSCA Structure is a structural optimization
> program. We use the Method of Moving Asymptotes (MMA of
> Krister Svanberg) as optimizer which in most cases does a
> really good job. In some cases though it has its drawbacks
> (linear object function, constraints which become active
> later in optimization) and we would like to test an
> alternative.
>
> Our problems may exceed 1 mio. design variables and we
> usually only need around 30-50 iterations to converge. The
> primal solution is a FEM system solved by an external
> program, the sensitivity analysis (1. order) is done by
> ourselves. We have no 2. order information.
>
> My questions:
> 1) How would you expect Ipopt to perform in a benchmark
> against MMA ? Has anybody got experiences?
> 2) We “warmstart” the optimization each iteration and
> leave the optimization to calculate the new primary
> solution. Thus we have changed the MMA so that we call it
> with objective function, constraints and sensitivities of
> the actual iteration plus some saved information from
> former iterations, e.g. the last asymptotes and other
> values. Could this be easily done with Ipopt ?
>
> We would prefer to use the fortran version, but
> interfacing to C++ is nothing new to us. It would simply
> mean that Ipopt’s objects would be created and destroyed
> each iteration (would this be a performance problem?).
>
> Best regards
>
> Peter M. Clausen, developer at FE-DESIGN GmbH
>
> _______________________________________________
>
>  Peter M. Clausen
>
>  Email: peter.clausen at fe-design.de
>  Tel. : +49 721 96467 - 236
> _______________________________________________
>
>  FE-DESIGN GmbH, Haid-und-Neu-Str. 7, 76131 Karlsruhe,
> Germany
>  Registration Court: D-Mannheim HRB 107382
>  Director: Dr. Juergen Sauter
>  Fax: +49 (0)721 96467-290
>  Web: www.fe-design.com
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