資源描述:
《中厚鋼板彎曲成形及冷卻過(guò)程的熱耦合分析》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫(kù)。
1、重慶大學(xué)硬士學(xué)位論文中文摘蒙摘要在汽率、拖撾機(jī)、機(jī)車(chē)車(chē)輛制造以及化學(xué)與鍋爐設(shè)備翩造部門(mén)里,薪中厚鎘扳采用彎躲方法制成的零{牛占有較大的比蓬。在實(shí)際工作中,常將厚度在5毫米~20毫米的鋼板稱(chēng)為中厚鋼板,其彎曲工芑在高溫下進(jìn)行;警車(chē)聞設(shè)備嚏鏹不足時(shí),甚至對(duì)于鞍薄的掇料(3~5舳)利用噸位較小的壓機(jī)工作時(shí)也強(qiáng)高溫下進(jìn)行;稅加工含鉻蹲特種鐨的零件瞎,如采在常海下加工會(huì)產(chǎn)生強(qiáng)烈的硬純、麓形及裂紋,故也在高溫下進(jìn)杼。板料熱彎鞠成形后,零侔冷卻至室海過(guò)程串,其冷收縮由兩部分組成:瓣浮方向上的收縮At與徑向收縮△R。△t可按常規(guī)方法計(jì)入收縮率來(lái)獲得,而△R若羧常規(guī)方法計(jì)算收縮量R嗦岔,涮實(shí)際絡(luò)采往往
2、與該傻蠢較大麓潮并可熊使模瑟報(bào)廢。冷卻過(guò)程中釣不臻勾冷卻弓l怒應(yīng)力穢變形祆蕊導(dǎo)致囂點(diǎn)的彀縮量不鬻,這怒引起收縮的內(nèi)在因素。而影響冷卻不均勻的原因很多,農(nóng)采用同一種冷卻方式的蘸捷下,諸螽零{夸冷幫懿靜形狀、表瑟饜鱟、冷幫囂虢滋度等瑟彎鏊{(lán)宰靜交形產(chǎn)生不同獠度的影響。為了得出中厚鋼板彎曲件在冷卻過(guò)程中所產(chǎn)生的收縮量,為模兵摻歪提供舍遴懿摻模羧據(jù),露必要分耩萁在冷顰蓬纛孛枝縮弱霞籜。本文以理論分析及有限元數(shù)值模擬棚結(jié)合的方式,對(duì)中厚鋼板彎曲成形過(guò)穰及冷幫逡疆率影餐
3、
4、受繚懿主要囂索遂霞了系統(tǒng)戇分凝,莽在魏蘩旗上餐蹬了這黢網(wǎng)索影響收縮的規(guī)律。最后利用最小二乘法對(duì)模擬結(jié)果進(jìn)行曲線擬舍得出收縮凝
5、與影翡囂爨之閡懿丞數(shù)關(guān)系,繪辮了數(shù)學(xué)表述式。為了針對(duì)相_陂的收縮量進(jìn)行合理的模具修正,本文以鋼板熱彎冷卻過(guò)程中商戮元節(jié)熹麓譴移多乏量關(guān)系必蘞擺攥導(dǎo)了模其驂委螽其型黌蘧線囊孽邋數(shù)關(guān)系,鬏撂該函數(shù)關(guān)系可方便地設(shè)計(jì)出相應(yīng)的彎曲模具。巒予影昀竣縛豹因素較多,攘瘟豹瀵數(shù)關(guān)系裝較是繁琰,焱實(shí)際生產(chǎn)瑰場(chǎng)蔽用十分不便,故將之進(jìn)行編程制成軟件以方便使用和參考。關(guān)鍵詞:中厚板,彎曲,冷卻,熱耦合,數(shù)值模擬重慶大學(xué)碩士學(xué)位論文英文摘要ABSTRACTIn也emanufactureofautomobile、tractor、locomotive、chemistryandboilerinstallation,t
6、hepartbybendingplatematerialhavealargeproportion.usually,forthesheetmaterialwhichthicknessisbetween5and20衄.thebendingtechniqueofitismadeunderhightemperature;whenthecapabilityofshopequipmentbenotenough,evenifthebendingofthinsheetmaterialiscarriedoutunderhightemperaturetoo;inaddition,theintenseco
7、ldworkhardening、warpandflawcanbecalrleintobeingwhentheshapingofthespecialsteelthatcontainchromiumbemadeunderloomtemperature,SOtheprocessbemadeunderhightemperature.Thethermalcontractionismadeoftwopart:oneistheAtwhichisiIlthedirectionofthickness.a(chǎn)notheristheARwhichisillthedirectionofradialdirecti
8、on.TheAtcanbeacquiredbyreckonninginthethermalcontractionratio.However,theareastrikingdissimilaritybetweentheARandtherealvalueandinducethemolddisablement.Thethermalstressandthermaldeformwhichbebroughtupbytheheterogeneouscoolinginducethedifferentexpansiononeachpoint,whichistheintrinsicfactorofthe
9、rmalcontraction.Therearemanyfactorwhichinfluenceonhomogeneousnessduringcooling.Onthepremiseofsametypeofcooling,theshape、surfacequality、temperatureofthepartisallinfluenceonthethermaldeform.Inordertoacquirethethermalcontractionvalue