FORMULAS

Emax = VƒEƒ + (1 - V₁) Em

1

=

CX gel [r+rs(f-2)]¹/2/nQ3

A mass of 10 kg is suspended from the ceiling on a steel wire of 1 mm diameter and 2 m length.

The mass is now rotated through an angle causing the wire to twist.

(a) Determine the shear stress Try in the wire as a function of the angle of twist 0. You may

assume that the steel has a shear modulus G = 80 GPa.

(6 marks)

(b) Estimate the maximum value of 0 if there is to be no plastic deformation. The steel has a

yield stress of 300 MPa and you may assume von Mises theory of yielding.

(14 marks)