Materials

Proportional Limit

The greatest stress for which stress and strain remain directly proportional.

Up to the proportional limit the stress-strain curve is a straight line and Hooke’s law applies. Past it the curve bends and the simple linear relation no longer holds.

It sits at or just below the yield strength, and the two are close enough that exam questions usually treat the distinction as a definition check rather than a calculation.

How much of the FE Civil exam is Materials?