《材料力學(xué)性能》中英文全套PPT課件

《材料力學(xué)性能》中英文全套PPT課件,材料力學(xué)性能,材料,力學(xué)性能,中英文,全套,PPT,課件 MechanicalTestsStaticTestsProperties:Elasticity,yield,plasticity,fracture,toughness,etc.性質(zhì)：彈性，屈服力，塑性，斷裂，硬度等Load:tension,compression,bending,torsion,etc.加載力：拉力，壓力，彎曲，剪切等Coefficientofsoftnessofstressstate:=max/max應(yīng)力狀態(tài)的柔性系數(shù)：=max/maxTensiontests:Engineeringstress/conditionalstress;Engineeringstrain/conditionalstrain.拉力實(shí)驗(yàn)：工程應(yīng)力；工程應(yīng)變.Engineeringstress/Engineeringstrain工程應(yīng)力/應(yīng)變Engineeringstress/conditionalstress:Theinstantaneousloadappliedtoaspecimendividedbyitscross-sectionalareabeforeanydeformation.工程應(yīng)力：瞬時(shí)載荷除以變形前的截面積大小。Engineeringstrain/conditionalstrain:Thechangeingaugelengthofaspecimen(inthedirectionofanappliedstress)dividedbyitsoriginalgaugelength.工程應(yīng)變：試樣標(biāo)距長(zhǎng)度的變化（加載力方向上）除以原始標(biāo)距長(zhǎng)度。Standardtensilespecimen標(biāo)準(zhǔn)拉伸試樣Stress-strainbehaviorofelasticdeformation彈性變形的應(yīng)力應(yīng)變圖Yieldingandyieldstrength屈服現(xiàn)象和屈服力Yielding:Theonsetofplasticdeformation.屈服：塑性變形的開始Yieldstrengthy:Thestressrequiredtoproduceaveryslightyetspecifiedamountofplasticstrain;astrainoffsetof0.002iscommonlyused.屈服極限應(yīng)力y：造成微量塑性變形所需的應(yīng)力，一般取0.002的應(yīng)變偏移量。Proportionallimit:thepointonastress-straincurveatwhichthestraightlineproportionalitybetweenstressandstrainceases.比例極限：應(yīng)力應(yīng)變曲線中應(yīng)力和應(yīng)變直線比例中正的地方。Tensilestrength拉力Tensile(ultimate)strength(TS):Themaximumengineeringstress,intension,thatmaybesustainedwithoutfracture.最大拉應(yīng)力（TS）：拉伸時(shí)，能持續(xù)而不發(fā)生斷裂的最大的工程應(yīng)力。Ductility延性DuctilityAmeasureofamaterialsabilitytoundergoappreciableplasticdeformationbeforefracture;itmaybeexpressedaspercentelongation(%EL)orpercentreductioninarea(%RA)fromatensiletest.材料在斷裂前發(fā)生塑性變形大小的度量。用拉伸試驗(yàn)中的長(zhǎng)度增加百分比(%EL)或面積減小百分比(%RA)來(lái)衡量。Stress-straincurvesofbrittleandductilematerials脆性和塑性材料的應(yīng)力應(yīng)變曲線Engineeringstress-strainbehaviorforironatthreetemperatures鐵在三種不同溫度下的工程應(yīng)力應(yīng)變曲線Truestressandstrain真實(shí)應(yīng)力與真實(shí)應(yīng)變Truestress:Theinstantaneousappliedloaddividedbytheinstantaneouscross-sectionalareaofaspecimen.真實(shí)應(yīng)力：瞬時(shí)載荷除以該時(shí)刻的瞬時(shí)截面積。Truestrain:Thenaturallogarithmoftheratioofinstantaneousgaugelengthtooriginalgaugelengthofaspecimenbeingdeformedbyauniaxialforce.真實(shí)應(yīng)變：由軸向拉力而變形的瞬時(shí)標(biāo)距長(zhǎng)度與其原始標(biāo)距長(zhǎng)度的自然對(duì)數(shù)。Ifnovolumechangeoccursduringdeformation若變形中無(wú)體積變化，則：Onlyvalidtotheonsetofnecking僅適用于頸縮開始前Typicaltensileengineeringstress-strainandtruestress-strainbehaviors典型的工程應(yīng)力應(yīng)變圖和真實(shí)應(yīng)力應(yīng)變圖Strain-hardeningexponent應(yīng)變硬化指數(shù)Fromtheonsetofplasticdeformationtothepointatwhichneckingbegins從塑性變形開始到頸縮開始前：Elasticrecoveryduringplasticdeformation塑性變形中的彈性回復(fù)Definitionsofandrelationshipsbetweentrueandengineeringstressandstrain真實(shí)/工程應(yīng)力應(yīng)變間的關(guān)系Stress-strainbehaviorofpolymers高分子聚合物中的應(yīng)力應(yīng)變圖Abrittle脆性Bplastic塑性C-highlyelasticpolymers高彈性Yieldandtensilestrengths屈服力和最大拉力Theinfluenceoftemperatureonthestress-straincharacteristicsofpolymethylmethacrylate溫度對(duì)聚甲基丙烯酸酯的應(yīng)力應(yīng)變的影響Schematictensilestress-straincurveforasemicrystallinepolymer半晶體聚合物的拉伸應(yīng)力應(yīng)變曲線problemAcylindricalspecimenofsteelhavinganoriginaldiameterof12.8mmistensiletestedtofracturedandfoundtohaveanengineeringfracturestrengthof460MPa.Ifitscross-sectionaldiameteratfractureis10.7mm,determine:(a)Theductilityintermsofpercentreductioninarea.(b)Thetruestressatfracture一個(gè)圓柱體鋼試樣，其初始直徑為12.8mm。受拉到斷裂，其斷裂的工程應(yīng)力為460MPa。若其斷裂時(shí)截面積為10.7mm，試確定：通過(guò)面積減小百分比計(jì)算的延展性及斷裂時(shí)的真實(shí)應(yīng)力。Graphicaldeterminationofproportionallimit圖像決定的比例極限D(zhuǎn)eterminationoftheyieldlimit確定屈服極限D(zhuǎn)eterminationofrelativeelongation相對(duì)拉伸長(zhǎng)度的確定ProblemInthetensiletest,ifaspecimenrupturednearoneendinsteadofinthemiddleofthegaugelength,howtodetermineitsrelativeelongation?在一個(gè)拉伸實(shí)驗(yàn)中，若試樣在一端斷裂而不是在中間斷裂，怎樣決定它的相對(duì)伸長(zhǎng)量。ProblemAcylindricalrodof380mmlonghavingadiameterof10.0mm,istobesubjectedtoatensileload.Iftheloadistoexperienceneitherplasticdeformationnoranelongationofmorethan0.9mmwhentheappliedloadis24500N,whichofthefourmetalsoralloysarepossiblecandidates?Justifyyourchoice(s).一個(gè)長(zhǎng)度為380mm的圓柱桿直徑為10mm受拉伸載荷。當(dāng)加載載荷為24500N時(shí)，它并未發(fā)生塑性變形且其伸長(zhǎng)長(zhǎng)度不超過(guò)0.9mm。下面四種金屬或合金中哪一種可能是該材料的組成成分？請(qǐng)做出選擇。Hardnesstests硬度測(cè)試Hardness:Themeasureofamaterialsresistancetodeformationbysurfaceindentationorbyabrasion.硬度：金屬抗受載或磨損變形的能力。Theeasiestandmostpopularmethodofmechanicaltestsofmaterials.是最簡(jiǎn)單最普通的測(cè)量材料力學(xué)的實(shí)驗(yàn)Researchstudiesandcontrolmeansinindustry.是工業(yè)上研究上控制的方法。Widelyusedinmanufacturingpracticefortheeaseandquicknessofmeasurement.是廣泛應(yīng)用的最簡(jiǎn)單、最迅捷的測(cè)量方法。Hardnesstestsareperformedmorefrequentlythananyothermechanicaltestforseveralreasons:硬度測(cè)試比其它測(cè)試更常用的原因：Theyaresimpleandinexpensive;簡(jiǎn)單便宜Thetestisnondestructive;對(duì)材料無(wú)損傷；Othermechanicalpropertiesoftenmaybeestimatedfromhardnessdata.其它力學(xué)性能通?？蓮挠捕葦?shù)據(jù)中推測(cè)出來(lái)。Thereaumurhardnesstest列式溫標(biāo)的硬度測(cè)試Atthebeginningof18thcentury;Trihedralprism三面體棱鏡Mohshardness莫氏硬度Atthebeginningof19thcentury;Ahardnessscaleforminerals,stillusedinmineralogy;金屬硬度范圍，仍用于礦物中Arranged10mineralsintoarowaccordingtotheirabilitytoscratchthesurfaceofotherminerals:將十種金屬根據(jù)它們?cè)诓牧仙峡毯鄣哪芰Ψ殖梢唤M10Diamond9Corundum8Topaz7Quartz6Orthoclase5Apatite4Fluorite3Calcite2Gypsum1TalcQuantitativehardnesstechniques硬度量度技術(shù)Asmallindenterisforcedintothesurfaceofamaterialtobetested,undercontrolledconditionsandofloadandrateofapplication.在規(guī)格條件、載荷和加載速率下，在材料表面形成一個(gè)微小的刻痕。Thedepthorsizeofindentationismeasured,whichinturnisrelatedtoahardnessnumber.刻痕的深度和大小被測(cè)量出來(lái)，并轉(zhuǎn)化成硬度指數(shù)。Rockwell,Brinell,KnoopandVickershardnesstests.Hardnesstestingtechniques硬度測(cè)試技術(shù)RockwellhardnesstestsIndentersincludesphericalandhardenedsteelballshavingdiametersof1/16,1/8,1/4,andin.,andaconicaldiamondindenter,whichisusedforthehardestmaterials.壓頭包手球狀的直徑為1/16,1/8,1/4和英寸的硬化鋼，一個(gè)圓錐形的剛玉壓頭用于測(cè)量最硬的材料。RockwellhardnessscalesandSuperficial表層Rockwellhardnessscales.HRA,HRB,HRCHR15N,HR30NRockwellhardnessscales硬度范圍SuperficialRockwellhardnessscales表層Rockwell硬度范圍Foreachscale,hardnessmayrangeupto130;however,ashardnessvaluesriseabove100ordropbellow20onanyscale,theybecameinaccurate.在每個(gè)范圍中，硬度可能達(dá)到130。但當(dāng)硬度達(dá)到100以上或20以下時(shí)，它們就變得不準(zhǔn)確了。Inaccuraciesalsoresultifthetestspecimenistoothin,ifanindentationismadetoonearaspecimenedge,oriftwoindentationsaremadetooclosetooneanother.Specimenthicknessshouldbeatleasttentimestheindentationdepth,whereasallowanceshouldbemadeforatleastthreeindentationdiametersbetweenthecenteroneindentationandthespecimenedge,ortothecenterofasecondindentation.試樣太薄，壓痕太靠近試樣邊緣，或兩個(gè)壓痕挨的太近，都會(huì)導(dǎo)致測(cè)量的不準(zhǔn)確性。試樣厚度應(yīng)該至少為壓痕深度的10倍，且兩個(gè)壓痕中心到邊緣距離和兩壓痕中心間距應(yīng)該為其壓痕直徑的3倍以上。Furthermore,testingofspecimensstackedoneontopofanotherisnotrecommended.Also,accuracyisdependentontheindentationbeingmadeintoasmoothflatsurface.另外，測(cè)量試樣不要彼此堆疊。并且，精度與平滑表面的刻痕有關(guān)。Brinellhardnesstest布氏硬度Thediameterofthehardenedsteel(ortungstencarbide)indenteris10.00mm.硬質(zhì)鋼（鎢碳鋼）壓頭的直徑為10.00mm。Standardloadsrangebetween500and3000kgin500-kgincrements;標(biāo)準(zhǔn)載荷范圍5003000kg，以500kg速度遞增Duringatest,theloadismaintainedconstantforaspecifiedtime(between10and30s).測(cè)試中載荷在特定時(shí)間（1030s）內(nèi)保持不變。Minimumspecimenthicknessaswellasindentationposition(relativetospecimenedges)andminimumindentationspacingrequirementsarethesameasforRockwelltests.Inaddition,awell-definedindentationisrequired;thisnecessitatesasmoothflatsurfaceinwhichtheindentationismade.HB試樣的最小厚度，壓痕距試樣邊緣的位置和壓痕間的最小間距與Rockwell硬度測(cè)試相同。另外，一個(gè)標(biāo)準(zhǔn)的壓痕也同樣重要：它需要一個(gè)平滑的平面。單位：HBKnoopandVickersmicrohardnesstestsKnoopandVickers微觀硬度測(cè)試Foreachtestaverysmalldiamondindenterhavingpyramidgeometryisforcedintothesurfaceofthespecimen.每次實(shí)驗(yàn)時(shí)，一個(gè)細(xì)小的三角形鉆石壓頭壓入試樣表面。AppliedloadsaremuchsmallerthanforRockwellandBrinell,rangebetween1and1000g.外加載荷（11000g）比Rockwell和Brinell測(cè)試小得多Theresultingimpressionisobservedunderamicroscopeandmeasured;thismeasurementisthenconvertedintoahardnessnumber.壓痕在顯微鏡下觀察測(cè)量，并轉(zhuǎn)化成相應(yīng)的硬度系數(shù)Carefulspecimensurfacepreparation(grindingandpolishing)maybenecessarytoensureawell-definedindentationthatmaybeaccuratelymeasured.為了精確測(cè)量一個(gè)良好有效的壓痕，試樣表面必需有所準(zhǔn)備（摩和擦）。TheKnoopandVickersarehardnessnumbersaredesignatedbyHKandHV,respectively,andhardnessscalesforbothtechniquesareapproximatelyequivalent.Knoop和Vickers硬度測(cè)試值分別由HK和HV表示，相應(yīng)地，兩種測(cè)量得到的硬度范圍是近似等效的。KnoopandVickersarereferredtoasmicrohardnesstestingmethodsonthebasisofloadandindentersize.Knoop和Vickers是根據(jù)載荷和壓頭大小的微觀硬度測(cè)量的方法。Hardnessconversion硬度轉(zhuǎn)化Correlationbetweenhardnessandtensilestrength硬度和拉力之間的關(guān)系A(chǔ)saruleofthumbformoststeels,theHBandthetensilestrengtharerelatedaccordingto對(duì)大多數(shù)鋼種而言，HB和最大拉應(yīng)力間的關(guān)系如下：Compressivetest壓縮實(shí)驗(yàn)Compressionofcylindricaltestpiecesisoneofthesoftestmethod.壓縮圓柱體實(shí)驗(yàn)是一種最常用的方法。Coefficientofsoftnessofstressstate:=max/max=2.應(yīng)力狀態(tài)軟性系數(shù)：=max/max=2Suitabletotestbrittlematerials.只適合于脆性材料。Testpiecepreparedforcompression壓縮實(shí)驗(yàn)件1-lowersupport下支撐點(diǎn)2-uppersphericalsupport上球支撐點(diǎn)3movablecross-pieceofthemachine可移動(dòng)及其部件4-testpiece試驗(yàn)件Compressioncurves壓縮實(shí)驗(yàn)曲線Conditionalandactualcompressiondiagramsofcopper銅的條件/真實(shí)應(yīng)力壓縮圖Ductility(intensiletest)張力測(cè)試中的延性Ductility延性percentelongation(%EL)orpercentreductioninarea(%RA)fromatensiletest.伸張實(shí)驗(yàn)中的長(zhǎng)度或面積變化百分比。Percentcontractionorpercentexpansioninareafromacompressivetest.壓縮測(cè)試中的長(zhǎng)度或面積變化百分比。TorsionalTests扭轉(zhuǎn)實(shí)驗(yàn)Fractureoftestpiecesintorsion試樣因扭轉(zhuǎn)而發(fā)生的斷裂Torsionaldiagram扭轉(zhuǎn)轉(zhuǎn)矩角度圖DetermineshearmodulusG剪切模量GValidintheelasticregion;彈性階段有效M-thetorque,kgf.m;轉(zhuǎn)矩l0-thegaugelength,mm;標(biāo)距-twistangleatthelengthl0,rad;扭轉(zhuǎn)角d0-the cross-sectional diameter,mm.截面直徑Determinethehighestrelativeshear最高相對(duì)剪切max=1-21and2aretheangularindicesattheendsofthegaugelength,rad;1和2是標(biāo)距末端的角度指數(shù)Conditional(engineering)strength條件（工程）應(yīng)力Proportionallimitpr;比例極限Yieldlimit0.3;屈服極限Conditionalultimatestrengthu.最大工程應(yīng)力Actual(true)ultimatestrength最大真實(shí)應(yīng)力Testsofpieceswithstressconcentrators有應(yīng)力集中的實(shí)驗(yàn)件Stressconcentrationcoefficientac應(yīng)力集中系數(shù)acmaxisthemaximumaxialstress;max是最大軸向應(yīng)力isthenominaloraveragestressinthenotchsection在刻痕處的平均應(yīng)力（名義應(yīng)力）cisindependentofmaterialsproperties.c獨(dú)立于材料的性質(zhì)Stressdistributionofalargeplate大平面上的應(yīng)力分布Stressdistributionfornotchedcylindricalsamples(elastic)圓柱體刻痕處彈性階段的應(yīng)力分布Stressdistributionfornotchedcylindricalsamples(elastic-plastic)圓柱體刻痕處在彈性到塑性階段上的應(yīng)力分布Fractograph(1)斷口組織Fractograph(2)NotchSensitivityRatio(NSR)刻痕敏感系數(shù)Bendingtests/Flexuralstrength彎曲實(shí)驗(yàn)/撓度強(qiáng)度a-concentratedbendingb-purebendingMaximumstresses最大應(yīng)力(a)(b)Three-pointbending,ASTMStandardc1161三點(diǎn)彎曲Flexuralstrength,bendingstrength,transverserupturestrength抗彎強(qiáng)度，彎曲強(qiáng)度，橫向斷裂強(qiáng)度Forarectangularcrosssection當(dāng)截面積為矩形時(shí)：Foracircularcrosssection當(dāng)截面積為圓形時(shí)Typicalbendingdiagramsaplasticmaterial塑性材料b-intermediatecase中間情況cbrittlematerial脆性材料Impacttestingtechniques撞擊實(shí)驗(yàn)技術(shù)Charpyimpacttest沙爾皮沖擊實(shí)驗(yàn)機(jī)Charpyimpacttest沙爾皮沖擊實(shí)驗(yàn)Impacttoughness(k):沖擊強(qiáng)度(k)k=mg(h-h)/A0Variablesincludingspecimensizeandshapeaswellasnotchconfigurationanddepthinfluencetheresults.其中的變化包括試樣的大小和形狀，洞的特征和深度對(duì)結(jié)果也有影響TheCharpyv-notch(CVN)techniqueismostcommonlyused.沙爾皮沖擊(CVN)實(shí)驗(yàn)技術(shù)仍被廣泛應(yīng)用。Ductile-to-brittletransition塑性到脆性的轉(zhuǎn)變Appearanceofthefailuresurfaceisindicativeofthenatureoffracture,andmaybeusedintransitiontemperaturedeterminations.Forductilefracturethissurfaceappearsfibrousordull(orofshearcharacter);conversely,totalbrittlesurfacehaveagranular(shiny)texture(orcleavagecharacter).Overtheductile-to-brittletransition,featuresofbothtypeswillexist.失效表面的出現(xiàn)是斷裂本質(zhì)的一種預(yù)兆，可以被應(yīng)用在轉(zhuǎn)變溫度的確定上。塑性斷裂表面是纖維狀和灰暗的。相反，脆性斷裂表面有晶體織構(gòu)（解理特征）。在塑性脆性轉(zhuǎn)變中，兩個(gè)特征都可能存在。NTD:NilDuctilitytemperature;無(wú)塑性轉(zhuǎn)變溫度50%FATT(FractureAppearanceTransitionTemperature):結(jié)晶區(qū)面積占整個(gè)斷面面積50%時(shí)的溫度叫做50%斷裂形貌(外觀）轉(zhuǎn)變溫度。DBTT:Ductile-to-BrittleTransitionTemperature.Notallmetalalloysdisplayaductile-to-brittletransition.FCCmetalsremainductileevenatextremelylowtemperatures.However,BCCandHCPalloysexperiencethistransition.Forthesematerialsthetransitiontemperatureissensitivetobothalloycompositionandmicrostructure.并不是所有的金屬都有一個(gè)塑性到脆性的轉(zhuǎn)變。面心立方結(jié)構(gòu)金屬合金在低溫下仍是塑性的。但體心立方和密排六方合金有這種轉(zhuǎn)變。合金成分和微觀結(jié)構(gòu)都對(duì)轉(zhuǎn)變溫度有明顯影響。InfluenceofcarboncontentontheCVNenergy-versus-temperaturebehaviorforsteel鋼中碳含量對(duì)CVN溫度能量變化的影響Problem1st1.1 A cylindrical specimen of aluminumhavingadiameterof12.8mmandagaugelengthof50.80mmispulledintension.Usetheload-elongationcharacteristicstabulatedbellowtocompeteproblemsathroughe.一個(gè)直徑為12.8mm，標(biāo)距為50.80mm的鋁圓柱體試樣受拉應(yīng)力作用。用下表中的載荷伸長(zhǎng)特征，完成a到e的問(wèn)題。(a)Plot the data as engineering stress versus engineeringstrain.在圖表上作出工程應(yīng)力應(yīng)變圖(b)Computethemodulusofelasticity.算彈性模量(c)Determine the yield strength at a strainoffsetof0.002.當(dāng)應(yīng)變?yōu)?.002時(shí)計(jì)算屈服應(yīng)力(d)Determinethetensilestrengthofthisalloy.計(jì)算合金的拉應(yīng)力(e)Whattheapproximateductility,inpercentelongation?算出相應(yīng)的延展性，由長(zhǎng)度百分比表示。A0=128.6mm2E=179.5/0.00299MPa=60GPaTS=369MPa屈服強(qiáng)度277MPa%EL=(59.182-50.8)/50.8*100=16.5%Problem2nd1.2Thefollowingtruestressesproducethecorrespondingtrueplasticstrainsforabrassalloy:黃銅的真實(shí)應(yīng)力，真實(shí)應(yīng)變Whattruestressisnecessarytoproduceatrueplasticstrainof0.25?為了形成一個(gè)0.25的真實(shí)塑性應(yīng)變，需多大的真實(shí)應(yīng)力？1.2Strain-hardeningexponent應(yīng)變強(qiáng)化的解釋K=630.957n=0.262=439MPaProblem3rd1.3 Consider a steel plate having a through-thicknessedgecracksimilartothatshownbellow;theplatewidth(W)is1000mm,anditsthicknessis 12mm.Furthermore,plane strain fracturetoughnessandyieldstrengthofthismaterialare80MPam1/2 and 1200MPa,If the plate is to beloadedtoastressof300MPa,wouldyouexpectfailuretooccuriftheonehalfcracklengthais15mm?Whyornot?一個(gè)平面鋼具有一個(gè)橫貫厚度的裂紋如下圖所示：平面鋼的寬度為1000mm，厚度為12mm。另外，斷裂時(shí)平面應(yīng)變硬度和屈服強(qiáng)度分別為80MPam1/2和1200MPa，當(dāng)裂紋長(zhǎng)度的一半a達(dá)到15mm時(shí)會(huì)斷裂嗎？為什么？1.3Stressintensitycoefficient(K)應(yīng)力強(qiáng)度系數(shù)Problem4th1.4TabulatedbellowaredatathatweregatheredfromaseriesofCharpyimpacttestsonaductilecastiron:(a)Plot the data as impact energy versustemperature.(b)Determinetheductile-to-brittletemperatureasthattemperaturecorrespondingtotheaverageofthemaximumandminimumimpactenergies.(c)Determinetheductile-to-brittletemperatureasthattemperatureatwhichtheimpactenergyis80J.下表中列出了球墨鑄鐵在一系列沙爾皮沖擊實(shí)驗(yàn)中的數(shù)據(jù)：a.作圖標(biāo)出沖擊能量和溫度b.確定對(duì)應(yīng)于最大和最小沖擊能量的平均值的塑性-脆性溫度c.確定沖擊能量為80J時(shí)塑性-脆性圖中的溫度