Determination of stress-strain relations from "offset" yield strength values
The shape of the stress-strain curve for a material is sometimes of considerable interest to the designing engineer. This is particularly true when he is dealing with members or elements subjected to compression, which become unstable at stresses beyond the elastic range. It is obvious that the two compressive properties commonly (modulus of elasticity and yield strength) are insufficient to define the shape of the stress-strain curve
Print Book, English, 1944
National Advisory Committee for Aeronautics, Washington D.C., 1944