Question

80 lb Statically Indeterminate Frame The frame consists of a steel and an aluminum bar, each of which is 1 in. thick. The bars are fixed to ground at A and B, and pinned to the rigid shortlink CD. Determine the moment reactions at A and B. Steel 1. 39 in. 0.5 in Aluminum Speed 01:09 / 18:18 info СС

Answer 1

0 80 lb 80-RI 3oin nch soin 0.5 Aluminium Steel Isteel = bd - 0.5x13 = 8/120 12 12 = 1/12 I Alumn= bd? = 1X² E Ested = 200upa Alumin= 696 hpa 8, = & (ie deflection in both red will be same) R, 4 (80-8,14,2 3(E) 3/EI Alum Steel RL 3 ( 200 X 69x1 10 (80- Rijx 8.33 1000 Rix 69 2 yao ya = R X 69 = 180-R) 100 R1169 = 8000 R1=47.33 lb

R2=80-R1 = 32.66 lb ma=RX30 in = 47.3x30 = 1420 11 db-inch Mo= R2X30 in = 32.66X 30 -32.66X30 - 949.86 nch parti & steel = 8 Splamain R, 42 3(EI) steel (120-21) 27 3 LEI Jaluri 110-R1) 69/21 20ox S 69t Rilles = 1200 10 ] = Ri=90.322 lb ~ 88.1 lb / option (b