06材料力学外语版

《06材料力学外语版》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、00习题要求：1.将题目转化为MicrosoftWord文档；2.解题过程用MicrosoftWord文档，公式用公式编辑器，只交电子文档作业；3.期末考试前必须作对所有所给题目，否则不能参加期末考试，请于指定时间前交作业。第一题(2010年3月5tl前交该题作业)星期五1*6ThewoodpolebsupportedbyMOcablesofI/4-indidmeter.Iheturnbucklesinthecablesarctighteneduntilthestressinlheethicsreaches60(K)0p$i,Iflhewo

2、rkingcompressivescrewsIbrwomJis2UUpsi,deicrmincthesmallestp^rmissabkdiameteroftlwpole.FIG,PI.61.21Determinethesmallestallowablecross-sectionalareasofmembersBD,BE，andCEofthetrussshown.Theworkingstressesare20000psiintensionand12000psiincompression.(Areducedstressincompressio

3、nisspecifiedtoreducethedangerofbuckling.)Thefree-bodydiagramofhomogeneousBCinFig.(b).Theequilibriumequationare工必尸=0,16x36-24P4v=0，P=24(kips)=24000(lb)B8ftPbd>1ibAPremPce36kipsP*yThefree-bodydiagramoftrussinFig.(c).Theequilibriumequationare4Q花+8X济^厂8X36®Pbd=—8.944(kips)(Com

4、pression)IX=0,8PAv-SPce=0PcE=24(kips)(Tension)工F、,=0,PAy-0J07PBE-36+PBD=0Pbe二ll・32(kN)(Compression)ThenormalstressofamemberCE,DEandDFisp8944//?aBD==<12000(//?/in.~)(Compression)ArdArdABD=0.745(in.37ComputethemaximumforcePthatcanbeappliedtothefootpedal.The1/4-in.-diameterpi

5、natBisinsingleshear,anditsworkingshearstressis4000psi.ThecableattachedatChasadiameterof1/8in.andaworkingnormalstressof20000psi.)aBE==HP%§12000(“/m.2)(Compression)^beABE=0.943(in.2)%=生=24000//?<20000(”")(Tension)Ace^ceABE=l・2(in?)i「SolutionThefree-bodydiagramofbracketinFig.

6、(b).Theequilibriumequationare6P-2TsinlO°=0,(a)P=0.05788TPBy=0.2315T工Fv=o,PBv-P-Tsinl0°=0,PBy=0.2315TAccordingtothenormalstressesformula,wehave7rxOA25in.Accordingtotheshearstressesformula,wehaveT=194.1(lb)Accordingtoformula(a)9wegetP=0.05788T=0.05788X194.1=11.2(lb)第二题(2010年

7、3月10日前交该题作业)星期三2.70270ForIhcsquareofProh.2.69,detenuin<;(hepurccnichaiigein(lieslopeofdiagonalDBdueiothepiessuri/aiiunofthevessel.2.69AI咐lsqiiiLicisbribedoildiuwok

8、spsij«0.30,dekirrnneth