Q)calculate the maximum stress induced in a cast iron pipe of external diameter 40 mm, internal diameter 20 mm and length 4 m when the pipe is supported at its ends and carries a point load of 80 n at the centre.
Q)calculate the maximum stress induced in a cast iron pipe of external diameter 40 mm, internal diameter 20 mm and length 4 m when the pipe is supported at its ends and carries a point load of 80 n at the centre. Given, external diameter D = 40 mm. internal diameter d = 20 mm. length of pipe l = 4000 mm centre point load p (80N) 1) moment of inertia for hollow circular section I=π/64 (D4-d4) I = π/64 (40^4 -20^4) I = π/64 (2560000 - 160000) I = π/64 * (2400000) I = π * 2400000/64 = 117809.724 mm4 2) Maximum bending moment for simply supported beam with central point load M=PL/4 80*4000/4 =8000n/mm 3) Distance from neutral axis to outer fibre (C) C=D/2 40/2 20 mm 4) Maximum bending stress σ = MC/I = 80000*20/117809.7 = 1600000/117809.7 = 13.58kn/mm2