Question

A beam with a square tubular cross section is subjected to the loading shown.   The cross section of the beam is also shown. Determine the maximum bending stress in the beam given:

L = 9 ft

P = 1,300 lb

d_o = 6 in

d_i = 5.4 in

1/3

Answer 1

P=13oolb 13001b в с 1 -3ft > 3ft- Ay = Reaction force on dleft support By = Reaction force at Right support take moment at B co Aux9 = 1300x6+ 1300x3 [Ay = 1300 lb ] Equating vertical forces Ayt By = 1300 + 1300 1300 +By= 2600 [By = 1300 lb a Bending moment Equation as a function of se (a measured from A) A toc Mox = + Ay x = + 1300 x Con for point A put xão Mazo lb ft O for pont c put ke 3 ft Mc= 1300x3 - Mc=3900 lb ft - from hic to D Mx = Ayx – 1300 (x-3) = 1300 X – 1300 X +3900 | Mrc= 00 lb ft I Constant from

from B to B Mge = Ay x – 1300 (2-3) -7300 (x - 6) =1300 X - 1300 (2-3) - 1300(3-6) for point B but x=qft MB = 1300x9-130019-3) -130019-6) K di Maximum bending moment (Absolute valec) Mmax = 3900 lb ft from Ctoo = 3900x 12 lbin do = 6 in di = 5.4in Moment of Inertia about didi horizontal Centroidol Axces, I= [d64 - c; 4) : eta [64-5144) I= 37-1412 int maximum bending Stress Tmax=' - Mmax doo Imax = 3900x12 x 37.1412 = 3780.168 psi romax = 317801 : ksil Answer cho