The orientation and magnitude of the finite strain, built up in simple
shear, and the orientation and rotation of material lines eventually
parallel to the long principal axis of the strain ellipse have simple
relationships with the shear strain. Off-axis Mohr circles for stretch
and reciprocal stretch allow convenient proof of such relationships,
whilst some of these are not often seen in existing structural literat
ure. In particular, it is noted that the shear strain in ideal simple
shear equals the difference of the principal stretches.