Upper and Lower Yield Points
"Luders Band" in Low-Caron Steel
Lüders bands, or Piobert's bands, appear on the surface of polished steel specimens during yielding. Of course, these bands are only the surface manifestation of three-dimensional zones of deformation: hence, the zones should probably be characterized as "wedges" rather than bands.From Mechanics of Materials, 4th Ed., by J.M. Gere and S.P. Timoshenko, PWS Publishing, 1997, pp. 835-42.
