中國石油大學(xué)工程力學(xué)考試Exam(11-12-1A)

A卷中國石油大學(xué)（北京）2011—2012學(xué)年第一學(xué)期《工程力學(xué)（雙語）》期末考試試卷考試方式（閉卷考試）班級：姓名：學(xué)號：題號IIIIIIIVVVI總分得分（試卷不得拆開，所有答案均寫在題后相應(yīng)位置）I (Total30points)Filluptheblankswithcorrectanswer.1. (4points)Stress-straincurvesforthreematerialsareshownbelow.Material(1,2,3)hasthehighestultimatestress.Material(1,2,3)hasthelargestelasticmodulus.2. (6points)Asshown,astraingageispastedonthesurfaceofacircularbarwithdiameterdtotestthetorquesactingontwoends.Ifelasticmodulusandpoission’sratioofthematerialareknownandthestrainingageis,thetorque=.(a)(b)(c)(d)3. (4points)Theboundaryconditionsonleftendforabeamasshownare.a.v’’(a)=0,EIv’”(a)=kv(a)b.v’(a)=0,EIv’”(a)=kv(a)c.v”(a)=0,EIv’”(a)=-kv(a)d.v’(a)=0,EIv’”(a)=-kv(a)(MPa)(MPa)4.(4points)AstresscycleisshowninFig.3,thecharacterofcycler=,themeanstress=,theamplitudeofstress=.5. (4points)Fortwobeamsmadeofsamematerial,thecorrectrelationshipfortheirmaximumdynamicstressesis.（1）d1<d2；（2）d1=d2；（3）d1>d2；(4)Cannotbejudged.PBAaaCIV (20points)AhorizontalbracketABCisfixedatsupportAandfreeatC.Thebracketisconstructedfromacircularcross-sectionalbarwithconstantdiameterd.AverticalloadPactsatthefreeendC.(1)Determinetheplacesofthecriticalpoints.(2)Drawstresselementstoshowthestressstateofthecriticalpoints.(3)Ifd=30mm,a=1m,P=180Nandtheallowablestressis[PBAaaCV (12points)Fortheprismaticbar,takingitsweightinconsideration,findthedisplacementofsectionB.LoadingF,l,crosssectionareaA,elasticmodulusEandmassdensityρa(bǔ)reknown.VI.(15points)Forthestaticindeterminatebeam,findthereactionatBwithenergymethod.isknown。PPabBACB卷中國石油大學(xué)（北京）2011—2012學(xué)年第一學(xué)期《工程力學(xué)（雙語）》期末考試試卷考試方式（閉卷考試）班級：姓名：學(xué)號：題號IIIIIIIVVVI總分得分（試卷不得拆開，所有答案均寫在題后相應(yīng)位置）I (Total30points)Filluptheblankswithcorrectanswer.1. (4points)Theboundaryconditionsonleftendforabeamasshownare.a.v’’(a)=0,EIv’”(a)=kv(a)b.v’(a)=0,EIv’”(a)=kv(a)c.v”(a)=0,EIv’”(a)=-kv(a)d.v’(a)=0,EIv’”(a)=-kv(a)2. (6points)Asshown,astraingageispastedonthesurfaceofacircularbarwithdiameterdtotestthetorquesactingontwoends.Ifelasticmodulusandpoission’sratioofthematerialareknownandthestrainingageis,thetorque=.(a)(b)(c)(d)3. (4points)Stress-straincurvesforthreematerialsareshownbelow.Material(1,2,3)hasthehighestultimatestress.Material(1,2,3)hasthelargestelasticmodulus.(MPa)(MPa)4.(4points)AstresscycleisshowninFig.3,thecharacterofcycler=,themeanstress=,theamplitudeofstress=.5. (4points)WeightofthebodyisW,andpushingforceisP.W=160N,P=500N.ThestaticandkineticslidingfrictioncoefficientsbetweentheweightandthewallareS=0.3andk=0.25respectively.Thenthefrictionbetweentheweightandthewallisa.150N;b.125N;c.100N;d.500N.6.(4points)Thebarsinthestructuresasfollowingaremadeofsamematerialandwithsamediameter.NBC1_____(>,=,<)NBC2,PCr1______(>,=,<)PCr2.7.(4points)Fortwobeamsmadeofsamematerial,thecorrectrelationshipfortheirmaximumdynamicstressesis.（1）d1<d2；（2）d1=d2；（3）d1>d2；(4)Cannotbejudged.II (13points)ForabeamshowninFig.II,drawitsbendingmomentandshearforcediagrams.CCBAFig.II.III (10points)Usingthemethodofcompositeareas,calculatecentroidalprincipalmomentsofinertiaandfortheshadedregionasshowninFig.III.Fig.III.IV (15points)Forthestaticindeterminatebeam,findthereactionatBwithenergymethod.isknown。PPabBACPBAaaCV.(20points)AhorizontalbracketABCisfixedatsupportAandfreeatC.Thebracketisconstructedfromacircularcross-sectionalbarwithconstantdiameterd.AverticalloadPactsatthefreeendC.(1)Determinetheplacesofthecriticalpoints.(2)Drawstresselementstoshowthestressstateofthecriticalpoints.(3)Ifd=30mm,a=1m,P=180Nandtheallowablestressis[PBAaaCVI. (12points)Fortheprismaticbar,takingitsweightinconsideration,findthedisplacementofsectionB.LoadingF,l,crosssectionareaA,elasticmodulusEandmassdensityρa(bǔ)reknown.C卷中國石油大學(xué)（北京）2011—2012學(xué)年第一學(xué)期《工程力學(xué)（雙語）》期末考試試卷考試方式（閉卷考試）班級：姓名：學(xué)號：題號IIIIIIIVV總分得分（試卷不得拆開，所有答案均寫在題后相應(yīng)位置）I (Total40points)Filluptheblankswithcorrectanswer.1. (5Points)Fig.I.1isatypicallow-carbonsteel-diagramintension.Suchadiagramconveysimportantinformationaboutthemechanicalbehaviorforthematerial.Pointarepresents______,pointbrepresents______,pointcrepresents______,pointdrepresents______,pointerepresents______.(1)yieldstress(2)ultimatestress(3)elasticlimit(4)percentelongation(5)proportionallimitFig.I.12. (5points)ApieceofchalkshowninFig.I.2issubjectedtoacombinationoftwistingandtension,failsontheα-degreeplanewiththelongitudinalaxis.ThesensesofthetorquesandaxialforcesmustbeindicatedasshowninFig..TTTPP(a)TTPP(b)TTPP(c)TTPP(d)Fig.I.23. (5Points)Forarealmemberundergoingrepeatedstress,itscharacterofcycler=.Whenr=,itsendurancelimitisthesmallest.a.b.c.+1d.–1e.0f.–g.0.54. (5points)Theboundaryconditionsonleftendforabeamasshownare.a.v’’(a)=0,EIv’”(a)=kv(a)b.v’(a)=0,EIv’”(a)=kv(a)c.v”(a)=0,EIv’”(a)=-kv(a)d.v’(a)=0,EIv’”(a)=-kv(a)Axy5.(5points)Whenatrainpassthroughasteelbridge,thestrainstestedbyinstrumentarex=0.0004,y=-0.00012atpointA.ThenormalstressesindirectionsxandyatpointAarex=,y=.(E=200GPa,=0.3,z=0)Axy6.(5points)Fortwobeamsmadeofsamematerial,thecorrectrelationshipfortheirmaximumdynamicstressesis.（1）d1<d2；（2）d1=d2；（3）d1>d2；(4)Cannotbejudged.7.(5points)WeightofthebodyisW,andpushingforceisP.W=160N,P=500N.ThestaticandkineticslidingfrictioncoefficientsbetweentheweightandthewallareS=0.3andk=0.25respectively.Thenthefrictionbetweentheweightandthewallisa.150N;b.125N;c.100N;d.500N.8.(5points)Thebarsinthestructuresasfollowingaremadeofsamematerialandwithsamediameter.NBC1_____(>,=,<)NBC2,PCr1______(>,=,<)PCr2.II (15points)ForabeamshowninFig.II,drawitsbendingmomentandshearforced