Treść książki
Przejdź do opcji czytnikaPrzejdź do nawigacjiPrzejdź do informacjiPrzejdź do stopki
36
SélimDatoussaïd,GuyGuerlement,ThierryDescamps
completelyindependentofthesimulationoneandcanbeadaptedtoanyfieldofengi-
neering,theyareveryrobustandconvergetoglobalandnotlocaloptimalsolutions.
Keywords:multibodysystems,kinematic,dynamic,structure,optimization,
evolutionarystrategy
1.INTRODUCTION
ComputerAidedDesignsimulationcodesarenowinescapabletoolsfor
studyingcomplexstructuralandmechanicalsystemsdependingonanimportant
numberofdesignvariables.Suchtoolsallowengineers:
•
tosimulaterapidlythesystembehaviourandanticipateitsresponsetosol-
licitationswhenagivenset(nbvalues)representedbyapointinsidethenb
dimensionsspaceofthedesignvariableshasbeenselected
•
toverifyifthetechnicalrequirementsorconstraintsimposedtotheresponse
arereachedwiththeselectedsetandtodeclareitasanallowabledesign
•
tolook,insidethesub-spaceofallowabledesigns,forthebestone,called
optimaldesignminimizingbytheuserarbitrarydefinedfunctiondepending
onthedesignvariablesandeventuallyontime.Thislastfunctioniscalled
theobjectivefunction.
Whenthenumberofdesignvariablesisimportant,itbecomeshardto
intuitivelymakeagoodchoiceofasetofthedesignvariablesandasystematic
optimizationprocedureneedstobeused.Theaimofthispaperistoreviewvery
brieflythedifferenttypesofexistingprocedures,tofocusontheiradvantages
andinconvenientsandtoapplyoneofthemtosomeoptimaldesignproblems
selectedinthefieldofstructural,kinematicordynamicmechanics.
2.GENERALMETHODSFOROPTIMIZATIONPROBLEMS
Aconstrainedoptimizationproblemconsistsinfindingthatsetofnbde-
signvariables,componentsofvectorbleadingtotheminimumvalueofanob-
jectivefunctionΨ0(b),expressedintermsofthedesignvariables,whilerespect-
ingncinequalityconstraintsonthedesignvariablesoftheformΨi(b)≤0corre-
spondingto:
•
inequalityconstraintsaffectingthedesignvariableswhichremainbetween
thelowerandupperboundaries
(2.1)