Determine the maximum stress in the bar:
A circular bar rigidly fixed at both of the ends is 1 m long & tapers uniformly from 20 cm diameter at one end to 10 cm diameter at the other end. Determine the maximum stress in the bar, if its temperature is grow up through 50oC. E = 2 × 105 N/mm2 and α = 12 × 10-6 K-1.
Solution
Here,
d1 = 20 cm = 200 mm
d2 = 10 cm = 100 mm
L = 1 m = 1000 mm
ΔL = 50°C
∴ σmax = Ed1 α ΔT/ d 2 =( 2 ×10 5× 200 ×12 ×10-6 × 50 )/100
= 240 N/mm2.