3005

126 دكتري

دكتري

﴿طراحي كاربردي﴾

اصفهان :دانشگاه صنعتي اصفهان، دانشكده مكانيك

1384

بيست، 159، [II]ص.: مصور، جدول، شكل، نمودار

ص. ع. به فارسي و انگليسي

محمود سليمي

محمدرضا موحدي، سعيد ضيايي راد

محمود فرزين، حسن خادمي زاده، كارن ابري نيا، حسن مسلمي نائيني

1395/12/14

كتابنامه

مهندسي مكانيك

ID126 دكتري

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

AbstractRolling is the most important processin metal forming in which a considerableamount ofmetalsare formed into different products Predictions rolling force and torque flatnessand ofvariationsin thicknessare the most importantaspects the analyses In rolling of plate and ofsheet in practice asymmetryarisesdueto inequalityin roll radii roll velocity and interface andfriction Thesevariations may causethe outgoingplate to be bentinto unexpected shapes Thisis known asturning up or turning downphenomenon Recentlythis type of rolling hasbecomemore and more important due to the fact that it requiresless rolling force and torque A fewresearchers have carried out experimentalinvestigationsand theoretical analyses study the toeffect of asymmetricalrolling Somepapersare not essentiallyable to predict the developedcurvature Only a few researchers were able to predict the developed curvature throughcomplex and time consuming computations In this thesis two different techniques areconsideredto analyzethe process The modified slab method and the Arbitrary LagrangianEulerianFinite ElementTechnique The modified slab method was employedand further developedto analyzethe asymmetricalplate rolling Based on some specific assumptions three equationsof equilibriums are thesolved and characteristics asymmetricalplate rolling due to inequality in surfacevelocity ofrolls radii and interface frictions are studied Elastic Plastic and linear work hardeningmaterial is assumed In solving he equilibrium equations it is assumedthat the pressuredifferenceover the roll gapis linearly distributed Basedon theseassumptions distribution theof shearforce the bendingmoment the meanpressure and the meannormal stressapplied tothe sheetare calculated The effect of forward and backward tensions and the thicknessreductionwith regardto the asymmetricalparameters rolling force rolling torque and the onoutgoingcurvatureare investigated The asymmetricplane strain rolling is also analyzedby using an elastic plasticALE finite elementmethod Resultsof ALE finite elementinvestigationof curvature development to due inequality in work rolls plate surface finish interface friction and speed mismatch arepresented Reasonable agreements were found between the numerical method andexperimentalresults ALE technique is found to be a convenient method for simulationsprocessessuch as asymmetrical rolling where the material is severely deformed and the outgoingplate may be deformedin an unexpected shape In this thesis an analytical model basedon Modified Slab Method of analysisfor rolling of clad sheetor double layerswhere the two layers are bounded prior to rolling is also given This model considersthe generalcaseof asymmetricalrolling due to unequalsurfacespeed different contactfriction roll diameters flow stressand thickness ratios of the two layers Using this model rolling parameterssuchas pressure distributionalong the arc of contactof the rolls and the clad sheet rolling force and torque with respectto reduction in thicknesscan easily be calculated The analytical rolling force and torque from the proposedmodel were comparedwith the analytical result of other investigatorswhich are shown to be in good agreements Presentmodel is very suitable for the online control application due to its completeness well as good pre4ictionof the rolling parameters as A tr f J A c

محمود سليمي

محمدرضا موحدي، سعيد ضيايي راد

محمود فرزين، حسن خادمي زاده، كارن ابري نيا، حسن مسلمي نائيني