Question 7

A delta strain gauge rosette (60° angles between gauges) bonded to a magnesium alloy

component, measured microstrain readings of 300, -240 and 60.

Determine the principal strains and from them the principal stresses and the maximum shear

stress at this point on the component (a) using analytical relationships and (b) by using

Mohr's circles for strain and stress.

The relevant material properties are: E = 80 x 10° N/m², v = 0.3.

(20 marks)