2014年电大建筑力学形成性考核答案1----4册

电大建筑力学形成性考核答案（14）电大建筑力学形成性考核答案力学11、选择题1B2C3C4C5B6D7B8D9A10D二、填空题1、垂直线2、中心线背离研究对象3、研究对象全部作用力4、平行原力对新作用点5、无关力偶矩大小6、力偶7、压力8、自由度9、虚铰瞬铰10、三角形三、计算题1、2、解3、见教材34页例题4、解体系内几何不变，且无多余约束。5、解6、7、解电大建筑力学形成性考核答案力学21、选择题1D2C3C4D5A6C7C8B9D10C2、填空题1、轴向拉伸或压缩剪切扭转弯曲2、扭矩MN用右手的四指表示扭矩MN的转向，拇指的指向离开截面则扭矩为正3、杆件轴线4、剪力5、零杆6、直线斜直线7、斜直线二次抛物线8、剪力集中力9、弯矩集中力偶10、力偶矩三、计算题1、解取截面左边部分为研究对象FXI0FN12F0得FN12F拉力同理可得FN20同理可得FN3F拉力2、解（1）求支座反力FXI0FAX400得FAX40KN（）MAF0FBY420424020得FBY60KN（）FYI0得FAY20KN（）（2）作弯矩图AC杆MAC0AC杆中截面弯矩MEA80KNM内侧受拉MCA80KNM（内侧受拉）CD杆MCD80KNM（内侧受拉）MDC0DB杆MDBMBD0（3）作剪力图用截面法求各杆端剪力AC杆FQAC40KNFQECFQCA0CD杆FQCD20KNFQDC60KN4作轴力图同理，用截面法求各杆件轴力，作出杆件轴力图3、解（1）求支座反力FXI0得FAX0MAF0FBY485420得FBY12KNFYI0得FAY8KN2画受力图，用假象截面在需求内力处将梁分成两部分，取其中一部分为研究对象，画受力图。3求内力，画受力图4、解1）求支座反力FYI0得FCY3FMBF0得FAX3FFXI0得FBX3F2）取结点B为脱离体，FXB0杆AB为零杆得杆BD的轴力FNBD3F（拉力）取结点A为脱离体，杆AD为零杆，FXA0得杆AF轴力FNAF3F（压力）取结点D结点为脱离体得FD杆为零杆，即FD杆的轴力为0DE杆的轴力为3F（拉力）取结点F结点为脱离体FYF0得FE杆件的轴力为（压力）FXF0得FG杆件的轴力为2F（压力）电大建筑力学形成性考核答案力学3一、选择题1C2A3B4D5D6C7C8D9C10D二、填空题1、常数横向变形系数2、等于3、几乎不增加增加4、弯矩最远5、强度刚度稳定性条件6、几何变形应力与应变的物理关系静力条件7、减小降低8、长度系数9、大10、计算长度3、计算题1、解1）求杆件轴力FNAB10KNFNBC10KNFNBC10KN2求杆件应力2、解1）圆环对形心轴X,Y的惯性矩2）矩形对圆环对形心轴X的惯性矩矩形对圆环对形心轴Y的惯性矩3、解1）求解AB杆、BC杆的轴力取B结点为研究对象，由平衡条件可求出4266XYDDID3312XBHBHI33YIBC杆的轴力AB杆的轴力2）校核AB、BC杆的强度BC杆的拉应力安全AB杆的压应力安全4、解1）求支座反力并绘制弯矩图，剪力图FA1611KNFB3914KN2校核正应力强度最大弯矩发生在B截面MMAX1016KNM最大正应力为3）校核剪应力强度最大剪力发生在B截面FQMAX2289KN最大剪应力应为安全5、解将作用力向形心简化可求的其轴向压力为FPFP1FP2201030KN截面弯矩为MZFP2E1000404KNM可得杆中压应力为6、解102SIN32COS1732NBCAFKN拉力）压力）3201406NBCFMPAPAA31717220NAB6MAXA210710ZMMPAAWMAXAX3289104826QFPAMPAA36MAX201401752PZFPAAW7、解长细比大，压杆细长，临届压力小，临界力也小，杆件容易丧失稳定A杆最先失稳电大建筑力学形成性考核答案力学4一、选择题1B2D3D4C5A6C7B8C9B10C二、填空题1、杆轴为直线2、位移3、轴力4、荷载力（力偶）5、反反6、位移7、未知的结点角位移和未知的结点线位移8、单跨超静定梁的组合体9、位移法10、转动三，计算题1、解在C点加竖向单位力，AB段和BC段坐标如图所示AB段BC段2解用图乘法计算（1）绘制实际荷载作用的弯矩图MP（2）作单位力作用下的弯矩图（3）横梁中点的竖向位移为3、（1）解（1）选取基本结构（2）建立典型方程（3）计算系数和自由项绘制图和MP图LIACB21M0822PQLXXL2/0041838LLPCQQXDXDXDEIIEIQL121423436PPPLLFLFLEIEI110PX1M（4）求多余未知力（5）作内力图4、（2）解其基本未知量为刚结点A的未知角位移Z1，刚结点B的未知角位移Z2，刚结点C的未知角位移Z3。5、解（1）计算固端弯矩和约束弯矩结点B处的刚臂的约束力矩（2）计算分配系数（3）计算分配弯矩（4）计算传递弯矩12146308906PEIEI175XKN2210675834080FABFBCLMKNMQLKNM756015FFBBABCMKNM24633423894217173BACBABCEIISIIEIE059135177BACMKNM050BABC2617170CABM（5）计算各杆的杆端弯矩，绘制弯矩图13571570FCABABABFBCBCBCMMMM“IFWEDONTDOTHATITWILLGOONANDGOONWEHAVETOSTOPITWENEEDTHECOURAGETODOIT“HISCOMMENTSCAMEHOURSAFTERFIFAVICEPRESIDENTJEFFREYWEBBALSOINLONDONFORTHEFASCELEBRATIONSSAIDHEWANTEDTOMEETIVORYCOASTINTERNATIONALTOURETODISCUSSHISCOMPLAINTCSKAGENERALDIRECTORROMANBABAEVSAYSTHEMATTERHASBEEN“EXAGGERATED“BYTHEIVORIANANDTHEBRITISHMEDIABLATTER,77,SAID“ITHASBEENDECIDEDBYTHEFIFACONGRESSTHATITISANONSENSEFORRACISMTOBEDEALTWITHWITHFINESYOUCANALWAYSFINDMONEYFROMSOMEBODYTOPAYTHEM“ITISANONSENSETOHAVEMATCHESPLAYEDWITHOUTSPECTATORSBECAUSEITISAGAINSTTHESPIRITOFFOOTBALLANDAGAINSTTHEVISITINGTEAMITISALLNONSENSE“WECANDOSOMETHINGBETTERTOFIGHTRACISMANDDISCRIMINATION“THISISONEOFTHEVILLAINSWEHAVETODAYINOURGAMEBUTITISONLYWITHHARSHSANCTIONSTHATRACISMANDDISCRIMINATIONCANBEWASHEDOUTOFFOOTBALL“THELACKOFAIRUPTHEREWATCHMCAYMANISLANDSBASEDWEBB,THEHEADOFFIFASANTIRACISMTASKFORCE,ISINLONDONFORTHEFOOTBALLASSOCIATIONS150THANNIVERSARYCELEBRATIONSANDWILLATTENDCITYSPREMIERLEAGUEMATCHATCHELSEAONSUNDAY“IAMGOINGTOBEATTHEMATCHTOMORROWANDIHAVEASKEDTOMEETYAYATOURE,“HETOLDBBCSPORT“FORMEITSABOUTHOWHEFELTANDIWOULDLIKETOSPEAKTOHIMFIRSTTOFINDOUTWHATHISEXPERIENCEWAS“UEFAHASOPENEDDISCIPLINARYPROCEEDINGSAGAINSTCSKAFORTHE“RACISTBEHAVIOUROFTHEIRFANS“DURINGCITYS21WINMICHELPLATINI,PRESIDENTOFEUROPEANFOOTBALLSGOVERNINGBODY,HASALSOORDEREDANIMMEDIATEINVESTIGATIONINTOTHEREFEREESACTIONSCSKASAIDTHEYWERE“SURPRISEDANDDISAPPOINTED“BYTOURESCOMPLAINTINASTATEMENTTHERUSSIANSIDEADDED“WEFOUNDNORACISTINSULTSFROMFANSOFCSKA“BAUMGARTNERTHEDISAPPOINTINGNEWSMISSIONABORTEDTHESUPERSONICDESCENTCOULDHAPPENASEARLYASSUNDATHEWEATHERPLAYSANIMPORTANTROLEINTHISMISSIONSTARTINGATTHEGROUND,CONDITIONSHAVETOBEVERYCALMWINDSLESSTHAN2MPH,WITHNOPRECIPITATIONORHUMIDITYANDLIMITEDCLOUDCOVERTHEBALLOON,WITHCAPSULEATTACHED,WILLMOVETHROUGHTHELOWERLEVELOFTHEATMOSPHERETHETROPOSPHEREWHEREOURDAYTODAYWEATHERLIVESITWILLCLIMBHIGHERTHANTHETIPOFMOUNTEVEREST55MILES/885KILOMETERS,DRIFTINGEVENHIGHERTHANTHECRUISINGALTITUDEOFCOMMERCIALAIRLINERS56MILES/917KILOMETERSANDINTOTHESTRATOSPHEREASHECROSSESTHEBOUNDARYLAYERCALLEDTHETROPOPAUSE,ECANEXPECTALOTOFTURBULENCETHEBALLOONWILLSLOWLYDRIFTTOTHEEDGEOFSPACEAT120,000FEETTHEN,IWOULDASSUME,HEWILLSLOWLYSTEPOUTONTOSOMETHINGRESEMBLINGANOLYMPICDIVINGPLATFORMBELOW,THEEARTHBECOMESTHECONCRETEBOTTOMOFASWIMMINGPOOLTHATHEWANTSTOLANDON,BUTNOTTOOHARDSTILL,HELLBETRAVELINGFAST,SODESPITETHEDISTANCE,ITWILLNOTBELIKEDIVINGINTOTHEDEEPENDOFAPOOLITWILLBELIKEHEISDIVINGINTOTHESHALLOWENDSKYDIVERPREPSFORTHEBIGJUMPWHENHEJUMPS,HEISEXPECTEDTOREACHTHESPEEDOFSOUND690MPH1,110KPHINLESSTHAN40SECONDSLIKEHITTINGTHETOPOFTHEWATER,HEWILLBEGINTOSLOWASHEAPPROACHESTHEMOREDENSEAIRCLOSERTOEARTHBUTTHISWILLNOTBEENOUGHTOSTOPHIMCOMPLETELYIFHEGOESTOOFASTORSPINSOUTOFCONTROL,HEHASASTABILIZATIONPARACHUTETHATCANBEDEPLOYEDTOSLOWHIMDOWNHISTEAMHOPESITSNOTNEEDEDINSTEAD,HEPLANSTODEPLOYHIS270SQUAREFOOT25SQUAREMETERMAINCHUTEATANALTITUDEOFAROUND5,000FEET1,524METERSINORDERTODEPLOYTHISCHUTESUCCESSFULLY,HEWILLHAVETOSLOWTO172MP