Huber's equation

Huber's equation, first derived by a Polish engineer Tytus Maksymilian Huber, is a basic formula in elastic material tension calculations, an equivalent of the equation of state, but applying to solids. In most simple expression and commonly in use it looks like this:

σ r e d = ( σ 2 ) + 3 ( τ 2 )

where σ is the tensile stress, and τ is the shear stress, measured in newtons per square meter (N/m², also called pascals, Pa), while σ r e d - called a reduced tension, is the resultant tension of the material.

Very useful in calculating the span width of the bridges like Golden Gate Bridge or Verrazano-Narrows Bridge, their beam cross-sections, etc.