The Vierendeel beam is an orthogonal lattice-shaped beam "Lattice (engineering)") invented and patented by Jules Arthur Vierendeel to whom it owes its name. It is a framework structure called "transitional"), as it allows large spans to be bridged "Luz (engineering)") (from 6 to 27 meters depending on the distance between verticals).[1]​ It is used in the construction of bridges (Vierendeel bridge) and in the construction of special beams that must cross large spans in buildings. It is usually used in materials such as metal, concrete or even wood (rarely). It is usually placed as a structural element in the form of a lintel.

The beam is formed by a series of horizontal chords and rigid vertical bars, like an orthogonal "Lattice (engineering)") lattice, which connects the upper chords with the lower ones without diagonal bars. It is therefore a beam with an internal lattice structure in the shape of a rectangle. This characteristic makes it also known as: vertical brace beam without triangular framework. I or H sections are usually used in the construction of this beam. The Vierendeel beam differs from "full web beams" and the lattice beam") in the way it absorbs shear forces. The patent was filed on May 29, 1897.