378 Static Equilibrium and ElasticityP12.69Member ACis not in pure compression or tension. Italso has shear forces present. It exerts a downwardforce SACand a tension force FACon Pin Aand onPin C. Still, this member is in equilibrium.FF FF FxACACAC∑=−′=⇒=′025.0 mA25.0 m14.7 kNCFACFACSACSACτA=∑0:−+′=14 725 050 00...kNmmafafafSACor′=SAC735. kNFSSyACAC∑+=⇒=14 77 3507 35.kNkNkNThen SSACAC=′and we have proved that the loading by the caris equivalent to one-half the weight of the car pulling down oneach of pins Aand C, so far as the rest of the truss is concerned.nAnEABCED25.0 m14.7 kN75.0 mFor the Bridge as a whole: A∑===+==∑14 725 0100036714 73 67011 0..kNmmkNkNkNkNafafnnFnnEEAAt Pin A:FFFFBABCAC∑∑+−°==°==11030000637sin...cos..kNkNkN compressionkNkN tensionbgafAt Pin B:FFyBCBCxBDBD∑∑°−==°+°−==60004240849.sinin..os.os..kNkN tensionkNkNkN compressionAt Pin C:FFyCDCDxCECE∑∑+°
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This note was uploaded on 12/14/2011 for the course PHY 203 taught by Professor Staff during the Fall '11 term at Indiana State University .