Question

ANswer = 0.114 in downward

Determine the vertic al displacement of joint C. The truss is made from A992 ste el (Fcy =50 ksi, Ec = 29.0 Msi) rods each having a dia meter of 1 in. 60° 60° i2 kip 6 ft 175 lins

Answer 1

Answer Take joint c Faca 60 FBC Efy = 0 12+ FBC Sino) = 0 FBc = -13.8564 kip E Fx=0 Fact Foc CBD(60) =0 FAC+673.8564) COS(60) = 0 > FAC = 6.9282 kip iz kip Take joint 2600> FAC Ź Fx co FAC+ FARCS(60)=0 → 6.9282 + FAR COS (60-) = 0 → FAB = -13-8564 kip 'FAB → place a virtual unit load at point c. A 160/6 1 kip Take joint c FAC Foc a kip Fy 20 + Famo) = 0 FBC =-1.1547 kip E Fx=0 FAC+ Fec COS(60) = 0 → FAC +(-1.1547) C8660) = 0 → FAC =0.57735 kip

Take joint A Q000 EFx=0 FAÇ + FABCO (60) =0 0.57735 + FAB C8(60) = 0 → FAB = -1-1547 kip FAB → Cakulate the vertical displacement at joint c. 1. A = = nNL AE Member n(kip) N(kip) LCin) (MNL) AB -1.1547 -13.8564 72 1152 6.9282 0.57735 288 AC 72 -1.1547 BC 13.8564 72 1152 EnNL = 2592 2592 1 kip. Ac = (29x10X720) = 0.114 in .. Ac = 0.114 in Aug Good Luck