MSR/ressources/Failure Theories.md

Videos descriptions#Failure theories

The hydrostatic stress is the average stress on all axis, it relates to the stress that want to change the volume like under water pressure (hence hydrostatic), by contrast to the deviatoric stress that act on the shape of the element.

For ductile materials :

The hydrostatic stress has no effect on failure.

Tresca : easier to apply, more conservative hexagonal prism in stress space

von Mises : better agreement with experimental data cylinder in stress space

For brittle materials :

Compressive strength >>> Tensile strength

The hydrostatic stress affects failure.

Coulomb-Mohr : general case of Tresca