Materials

Yield Strength

The stress at which a material begins to deform permanently.

Below the yield strength a material returns to its original shape when unloaded. Above it, some deformation remains permanently.

For materials without a sharp yield point, yield strength is conventionally defined by an offset method: the stress where a line parallel to the elastic region, offset by a small strain, intersects the curve.

How much of the FE Civil exam is Materials?