Question

Difference between the plane stress and plane strain

Answer 1

stress acting on a plane
stain in a plane

Answer 2

Plane stress condition can be visualized as thin plate withstresses acting along its plane. There is no stress acting perpendicular to to the the plane and ( ∂ / ∂ z ) components in equations are zero. Plain strain can be idealized as long wire with stresses acting perpendicular to its length.