STRESS AT A MATERIAL POINT

Resolve traction on a rotating cut

Theory ↗
Plane stress · σzz = σxz = σyz = 0
n unit normalt totalσₙn normalτm shear
Normal σₙ—
Signed shear τ—
Traction ‖t‖—

Mohr’s circle σₙ versus signed τ · MPa

Traction as the cut rotates 0–180° repeats