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posted by  jgiles69@nmsu.edu on 10/31/2009 3:14:01 PM  |  status: Closed  |  Earned Karma: 25

Ooops!!

Course Textbook Chapter Problem Needs by
Classical Mechanics Mechanics of Materials (5th) by Beer, Johnston, DeWolf 6 16P 11/1/2009 at 5:00:00 PM
Question Details:
Find largest P, Max. normal stress=160MPa, Max. shear stress=V/A(web)=100MPa,
Beam is W360x122, A=1500mm, d=363mm, flange width=257mm, thickness of web=13mm, inertia(x)=365x10^6 mm64, inertia(y)=61.5x10^6mm^4
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posted by harry9(MNK) on 11/6/2009 2:35:12 AM  |  status: Live
Asker's Rating: Helpful   
Response Details:
For W360*122

Aweb = 15700 mm2

S=2030*10-3 mm3

Reactions:

Ra+Re = 3P

and take moment about A

-P*0.6-P*1.2-P*1.8+Re*3.6=0

Re=P and Ra = 2P

So maximum vertical shear V=2P and vertical shear is zero between C and D,So bending stress is maximum between C and D

Mmax = P*0.6+P*1.2

Mmax =1.8 P

bending stress σ = M/S

160*106 = 1.8P/2030*10-6

P= 180.44 kN

shear stress τ =V/Aweb

100*106 =2P/15700*10-6

P= 785kN

So P=180.44 N

(check for calculations)
harry
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