Question

NAME: DET 403-Design of Machine Elements Chapter 6 Design Problem Due in class Tuesday, October 22, 2019 (1) A pipe made of SAE 1137 OQT 1300 steel is to have an outside diameter of D 10 in, and is to support a tank of liquid fertilizer weighing W = 75 kips when full, at a height H 20 ft above the ground level, as shown in the figure below. The pipe is set vertically in a heavy, rigid concrete base. A safety factor of 3 is desired. (a) Determine the minimum wall thickness t that should be used for this application. (b) Also, calculate the normal stress due to compression of the pipe using the value of t determined in (a). How does this compare with the yield stress of the material? [Hints: (i) Start by relating the expression for the moment of inertia of the cross section from geometry and from the critical load. (i) Note that the pipe is fixed to the concrete base but free to swing with the tank.] Be sure to first write down each equation you use/want to use before substituting numerical values. ४ D

Answer 1

ANSWER:

Griven D-lo in W=75 kips height H = 20ft. Safely facfox = 8. 6-2900 ksi 6=29X106 psi H=2544= 300 in PCT 261 412 e pe q ze xe (604-6,4) HL?. 75009 - T?y29x1067(104.0.4) 4x(30072 3000 - 9.18x29x106.(1040) Их Ҷодоод 3000 = 623.482761040)

Di -9.998 in t-Do-Di =10-9998 | t=0012?n] b) Normal stress - (00303) - 75X103 7110299882) ; 75X103 (100-99.760144) = 75x103 (0:24) = 754103 0.1884 U : 396644.45 psi 0-3.966X100 10- 396.6 ksi Jyield49893 ksi Since normal stres is very large compared to Yield Strength of Sleel, the column will break