Question

A continuous cable (diameter 6 mm) with tension force T is attached to a horizontal frame member at B and C to support a sign structure, Fig. 1. The cable passes over a small pulley at D. The wire is made of a copper alloy, and the stress-strain relationship for the wire is (a) Find the axial normal strain in the cable and its elongation due to the load W = 6.8 kN (b) If the forces are removed, what is the permanent set of the cable. Hint: Start with constructing the stress-strain diagram and determine the modulus of elasticity, E and the 0.2% offset yield stress

Answer 1

$\sigma$ = $\frac{T}{A}$

$\sigma$ = $\frac{4.1548\times10^3}{(\frac{\pi}{4})\times(0.006^2)}$

$\sigma$= 146943.47$\times10^3$

$\sigma$=146.943Mpa