# Plate with a circular hole in tension (Kirsch)

A quarter of a square plate of half-width 30 with a hole of radius 1 (W = 60a, so the infinite
plate's solution applies to a few tenths of a percent), thin (free faces, plane stress), with
symmetry on x = 0, y = 0 and the mid-plane, pulled by a traction of 1 on x = 30. Two hex20 blocks
around the hole (40 × 16 each), graded 40 : 1 towards it. Kirsch: σ_θ = 3S at the top of
the hole, −S at its side.