[Ipopt] ipopt in structural optimization

[Peter Clausen]

Yes, I have also found a similar statement on:
http://piezo-optimization.blogspot.com/2007/03/comparing-ipopt-with-optimality.html

But I guess if one had time you could tune IPOPT to behave better.

Has anyone a comment on the “warmstart” issue?

Thanks in advance.

/Peter

> Ruhollah Tavakoli wrote:
>> 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 <mailto:peter.clausen at fe-design.de>> wrote:
>>
>>     Hello
>>
>>     I am working at FE-DESIGN GmbH (www.fe-design.com
>>     <http://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 
>> <mailto: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 <http://www.fe-design.com/>
>>     _______________________________________________
>>
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>>
> 

-- 
Mit freundlichen Grüßen / Best Regards

Peter M. Clausen

_______________________________________

  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
_______________________________________________________________

Veranstaltungsvorschau:
+++ 10.-13.März 2009 in Lyon: "Industrie Lyon 2009" +++
+++ 23.-24.März 2009 in London: "STAR European Conference+++
+++ 30. März – 01. April 2009 in Karlsruhe: „TOSCA Structure Einführungsseminar (Deutsch)“ +++
+++ 20.04.-24.04.2009 in Hannover: "HMI"+++
+++ 27.04.-28.04.2009 in Graz: "2nd Graz Symposium Virtual Vehicle"+++
+++ 02. April 2009 in Karlsruhe: „TOSCA Sructure Advanced Seminar (Deutsch)“ +++
+++ 20.04.-24.04.2009 in Hannover: "HMI"+++
+++ 27.04.-28.04.2009 in Graz: "2nd Graz Symposium Virtual Vehicle"+++
+++ 18.-21. Mai 2009 in London: "SIMULIA Customer Conference" +++

Event Preview:
+++ March 10-13, 2009 in Lyon/France: "Industrie Lyon 2009" +++
+++ March 23-24, 2009 in London/GB: "STAR European Conference"+++
+++ March 30-April 01, 2009 in Karlsruhe/Germany: “TOSCA Structure Basic Seminar (German)” 
+++
+++ April 02, 2009 in Karlsruhe/Germany: “TOSCA Structure Advanced Seminar (German)+++
+++ April 20-24, 2009 in Hannover/Germany: "HMI"+++
+++ April 27-28, 2009 in Graz/Austria: "2nd Graz Symposium Virtual Vehicle"+++
+++ May 18-21, 2009 in London/GB: "SIMULIA Customer Conference"+++