Problems 211[5] Jenkins, W.M.,Matrix and Digital Computer Methods in Structural Analysis, McGraw-Hill Publishing Co.
Ltd.,1969.
[6] Zienkiewicz, O.C., and Cheung, Y.K.,The Finite Element Method in Structural and Continuum Mechanics,
McGraw-HillPublishingCo.Ltd.,1967.
Further Reading
Zienkiewicz,O.C.,andHolister,G.S.,StressAnalysis,JohnWileyandSonsLtd.,1965.
Problems..............................................................................................
P.6.1 FigureP.6.1showsasquaresymmetricalpin-jointedtruss1234,pinnedtorigidsupportsat2and4and
loadedwithaverticalloadat1.TheaxialrigidityEAisthesameforallmembers.
Usethestiffnessmethodtofindthedisplacementsatnodes1and3andhencesolveforalltheinternalmember
forcesandsupportreactions.
Ans. v 1 =−PL/√
2 AE,v 3 =−0.293PL/AE,S 12 =P/ 2 =S 14 ,
S 23 =−0.207P=S 43 ,S 13 =0.293P
Fx,2=−Fx,4=0.207P,Fy,2=Fy,4=P/2.Fig. P.6.1