The problems for Section 2.9 involve the determination of principal strains and maximum sh...

The problems for Section 2.9 involve the determination of principal strains and maximum shear strain from measurements by strain rosettes.

Show that for Example 2.12, when θ = 45°, the principal strains are given by

and the maximum strain ϵ1, is located at angle ϕ, counterclockwise from the x axis, where

Example 2.12.