Question

A copper rod 25 mm in diameter is encased in steel tube 30 mm internal diameter and 35 mm external diameter. The ends are rigidly attached. The composite bar is 500 mm long and is subjected to an axial pull of 30 kN. Find the stresses induced in the rod and the tube. Take E for steel = 2 x 10⁵ N/mm² and E for copper as 1 x 10⁵ N/mm² .

Answer 1

Let us use suffix 1 for rod (copper) and 2 for tube (steel)

From (1) 2p₂ (490.9) + p₂ (255.3) = 30000 

Solving p₂ = 24.25 N/mm² and p₁ = 2p₂ = 48.5 N/mm²