Question

12.19 and 12.20 Draw the shear and bending-moment diagrams for the beam and loading shown, and determine the maximum normal stress due to bending

Answer 1

25 kips askips 25 kips oooo 1ft oft oft 25 25 TRB Ift 25th oft af Moment about ß must be zero = 25x11- RCX 10 + 25 X 8 + 25x2 no 2) 10Rc = 25x21 C RC = 52.5 kips. 2 FX 20 25+25+25= Ret RB 2 RB = 75-52.5 = 22.5 kips for section s 12235 Ix= 229 In4 --- tett.h (from table ) Bending stress (6) 5.078 I 12 in W Y max = 6in.

shear force and Bending Moment diagram 25 52.5 22.5 2.1 27.5 S.FD. +22.5 kips 45 l B.M.D. (kips-ft) V25 kips-ft M = -250 act ft 27. 5x-52.5 1< x<3 2.50 +22.5 3<x<a Maximum bending stress (6) max = M max Imax - 45x10 3 x 12 229 x 6 : 14148.47 psi = 14.15 ksi