Question

What is the correct statement regarding the stress over the section of a shaft in torsion?

a) A normal stress that varies linearly over the section
b) A normal stress that is uniform over the section.
c) A shear stress that is uniform over the section.
d) A shear stress that varies linearly over the section

Answer 1

Answer:

d) A shear stress that varies linearly over the section.

Explanation:

Given that shaft is under pure torsion

As we know that relationship between shear stress in the shaft and radius given as

$\dfrac{T}{J}=\dfrac{\tau}{r}$

For solid shaft

$J=\dfrac{\pi}{64}d^4$

Therefore shear stress given as

$\tau=\dfrac{T}{J}\times r$

T=Applied torque on the shaft

τ=Shear stress at any radius r

From the above equation we can say that shear stress is vaying linearly with the radius of the shaft

Therefore the answer will be d.