Concept

Principal stress — where it appears

The direct stresses on the two planes at a point where the shear stress vanishes, which are also the largest and smallest direct stresses there. Every yield criterion is written in them, and recovering them from stresses in the axes a structure was drawn in is what a Mohr circle does.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

Both at once, and neither matters until it does

A section carrying shear has less moment capacity, and the reduction is the web's share of the plastic modulus times one minus the root of one minus the shear ratio squared. On a rolled beam that share is a quarter, so half the shear capacity costs three and a half per cent — and then the last tenth costs more than the first eight.

sections · shear moment interaction

The shear strength nobody measured

Every web on this site is checked against the yield stress divided by the square root of three, and no test produced that number. It is a consequence of a decision about what makes a metal yield, and the alternative decision gives a different answer by fifteen per cent.

materials · yield criterion

Named alongside it

The objects these essays reach for when they reach for this one.

Von mises Yield criterion Bending stress Confinement Continuous beam Deviatoric stress Ductility Equivalent stress Flange Hydrostatic stress Interaction Interaction diagram

All concepts