A round bar 40 mm dia meter is subjected to an axial pull of 80 kn and reduction in diameter was found to be 0.00775mm.find poisson's ratio and young's modules for the material of the bar. take value of shear modules as 40kn/mm square.

Answer 1

Assuming an isotropic and elastic material,

εy=-0.00775/40
σx=80 kN
G=40 N/mm^2 (40 kN was probably a typo)

Use
εy=(σy-ν(σx+σz))/E ....(1)
and
G=E/[2(1+ν)] ...(2)

Solve for ν by substituting
E=2G(1+ν) from (2)
into (1)

εy=(σy-ν(σx+σz))/[2G(1+ν)]

and solve for ν.
Substitute ν into (2) to find E.

I get ν=0.24, E=99.2 MPa

Answer 2

Give the answer