- #1
Apple&Orange
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Homework Statement
A) A circular rod is subjected to a bending moment of 315Nm. What is the minimum diameter of the rod required so that the maximum stress does not exceed 200N/mm2?
B) If the Modulus of Elasticity for the material from which the rod is made of is 100kN/mm2, what radius will the rod be deformed to when stressed to the maximum allowable?
Homework Equations
A) [itex]\frac{M}{I}[/itex] = σ
B) [itex]\frac{M}{σ]}[/itex] = [itex]\frac{ρ]}{E]}[/itex]
Second moment of Area for a circle of diameter d, about its Neutral Axis is [itex]\frac{∏d}{64}[/itex]
The Attempt at a Solution
A) M=314N/m
σ=200MN/m2
I=[itex]\frac{∏d]}{64}[/itex]
[itex]\frac{314}{[itex]\frac{∏d}{64}[/itex]}[/itex]=200×106
d=0.0752m
B) M=413Nm
E=100GN/m2
σ=200MN/m2
[itex]\frac{314}{200×106}[/itex]=[itex]\frac{ρ}{100×109}[/itex]
ρ=157,000m (Ridiculous answer, I know)
I haven't done mechanics in a while, so I was wondering if someone could double check that I'm on the right track.
Chuur Chuur