無(wú)網(wǎng)格法中本質(zhì)邊界條件實(shí)施研究.pdf

1、分類(lèi)號(hào)立242密級(jí)——西北工業(yè)大學(xué)碩士學(xué)位論文(學(xué)位研究生)學(xué)校代碼—』!L學(xué)號(hào)鯉魚(yú)141氈論文題目：無(wú)網(wǎng)格法中本質(zhì)邊界條件實(shí)施研究作者董查強(qiáng)指導(dǎo)老師基玉蝰專(zhuān)業(yè)技術(shù)職務(wù)副數(shù)撞學(xué)科、專(zhuān)業(yè)讓箕數(shù)堂零零七年二月西安婀北工業(yè)大學(xué)AbstractInrecentyears，meshlcssmethodshavebeenproposedandachievedremarkableprogressinnumericalcomputations，them

2、ainfeatureofwhichisthattheyonlyneedinformationofnodalparametersinsteadofelementsinformationandthemeshcanbeeliminatedwhollyorpartlySothedifficultyinmeshgenerationofthestructureisreducedFurthermore，theyalsohaveothermerits，

3、includingthehighaccuracytheconvenienceofthepostprocessorandsoonAlotofsortsofmeshlessmethodswcrepresentedbynativeofforeignscholarsandappliedtotheengineeringpracticeinthepastdecadesManytheoreticandappliedachievementswereac

4、quiredSofartheoreticalresearchesaswellasrelativeapplicationsaboutmeshlessmethodsarestillinthestageofinfancyConsideringtheexistingkeyproblemsofmeshlcssmethods，impmvedtechniquesarediscussedindetailOnthebasisofrcadingalotof

5、literatures，theadvantagesanddisadvantagesofEFGMandbasistheoryofmeshlessmethodareintroducedThephysicalmeaningofMLSreversibilityofmatrixA，selectionofweightfunctionandthePenaltyfactortheproperradiusofsupportdomainandthechar

6、acteristicofapproximatefunctionareinvestigatedindetailAspecialtreatmentisneededtealjzetheessentialboundaryconditionsformeshfreemethodwhilemovingleastsquaredmethodisusedtoapproximatetheunknownfieldfunctionsThisiscausedbyt

7、hefactthatmovingleastsquareapproximationisjustakindoffittingmethodwithoutinterpolationcharacteristicsInthispaperafterintrodudngthemeshlessmethodsimplywediscusseverykindofmethodsonimplementationofessentialboundaryconditio

8、nsindetailandcomparesadvantagesandshortcomingsofseveralkindsofmethodsBesidestheabove，anewmethodthattheMedifiedPenaltyisproposed，essentialboandaryconditionwasforcedbyintroducingLagrangemultipliersfwstlyToenrichthepositive

9、definiteofstiffnessmatrix，theLagrangemultitliersisidentified器boundaryforce，thenamodifiedvariationalprinciplewasobtainedToimprovethecomputingaccuracyPenaltyfactorisinducedintheobtainedprincipleComparingwiththePenaltymetho