Hello, I'm a bit confused on my coursework when calculating the bending moment, friends are saying different things and I don't know anymore.

We have a thin walled cylinder that is simply supported over 8m and it has a mass of 15000kg. The inner diameter is 1750mm and it has a wall thickness of 10mm. The cylinder operates at a pressure of 0.075 Mn/m^2 and during operation it is subjected to an axial force of 150kN and a torque of 800 kNm.

(i) Calculate the component stresses

(ii) Evaluate the 2D complex stress system

It was not stated if it was a udl or point load so we kinda just assumed it was a udl therefore;

F = m*g

F = 15000*9.8

F = 147000N

M = W x L /8

M = 147000 x 8/8

M = 147000 N/m

M = 147x10^6 N/mm

Is this correct? My friend says he has proof that it can be a point load but hasn't showed me the literature.

sigma d = -F/A = 150x10^3/55292.03

sigma d = -2.7 MN/m^2

sigma h = pd/2t = (0.075x10^6)x1.75/2*0.01

sigma h = 6.6MN/m^2

sigma l = pd/4t = (0.075x10^6)x1.75/4*0.01

sigma l = 3.3MN/m^2

tau = Tr/J = (800x10^3)x0.885/0.043

tau = 16.5MN/m^2

J was calculated as 0.043m^4

I was calculated as 2.141x10^10mm^4

Once I figure out the bending stress I'm going to determine the magnitude of the principal stressses analytically and graphically.

We have a thin walled cylinder that is simply supported over 8m and it has a mass of 15000kg. The inner diameter is 1750mm and it has a wall thickness of 10mm. The cylinder operates at a pressure of 0.075 Mn/m^2 and during operation it is subjected to an axial force of 150kN and a torque of 800 kNm.

(i) Calculate the component stresses

(ii) Evaluate the 2D complex stress system

It was not stated if it was a udl or point load so we kinda just assumed it was a udl therefore;

F = m*g

F = 15000*9.8

F = 147000N

M = W x L /8

M = 147000 x 8/8

M = 147000 N/m

M = 147x10^6 N/mm

Is this correct? My friend says he has proof that it can be a point load but hasn't showed me the literature.

sigma d = -F/A = 150x10^3/55292.03

sigma d = -2.7 MN/m^2

sigma h = pd/2t = (0.075x10^6)x1.75/2*0.01

sigma h = 6.6MN/m^2

sigma l = pd/4t = (0.075x10^6)x1.75/4*0.01

sigma l = 3.3MN/m^2

tau = Tr/J = (800x10^3)x0.885/0.043

tau = 16.5MN/m^2

J was calculated as 0.043m^4

I was calculated as 2.141x10^10mm^4

Once I figure out the bending stress I'm going to determine the magnitude of the principal stressses analytically and graphically.

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