Question

A shaft of circular cross section (diameter = 3 in) is subjected to a bending moment of 3200 lb- ft. Determine the bending stress at the surface of the shaft.

Answer 1

Answer:

 $\sigma =145.62 MPa$

Explanation:

Given that

Diameter  of shaft=3 in      (1 in=0.0254 m)

Bending moment=3200 lb-ft      (1 lb-ft=1.35 N-m)

We know that bending stress in circular shaft given as

$\sigma =\dfrac{32M}{\pi d^3}$

Where M is the bending moment and d is the diameter of shaft.

Given that M=4338.61 N-m

            d=0.0672 m

Now by putting the values

$\sigma =\dfrac{32\times 4338.61}{\pi \times 0.0672^3}$

So  $\sigma =145.62 MPa$