Some More Truss History…..Vierendeel Truss Design
In a previous post, I gave some background on the history of truss design and examples of trusses from ancient times to trusses we encounter in our daily lives. You can view that post here.
Trusses have been around for a long time as evidenced by the use of trusses in ancient structures. People figured out how important the triangle was in the design of structures. When analyzing a triangulated truss you can make the assumption that the joints are pinned and that there is no bending moment at the joint. The sum of the forces and sum of the moments will equal zero at the joint.
A gentleman from Belgium put his own spin on truss design. His name was Arthur Vierendeel. He was a civil engineer and university professor born in Leuven, Belgium in 1852. In 1895, he had the idea of creating a bridge without the use of trusses, which would be known as the Vierendeel bridge. These structures do not employ the use of triangulated members, but rectangular openings and rigid connections which must resist substantial bending moments.
Vierendeel Bridge in Grammene, Belgium
This type of “truss” is commonly used in structures where large shear walls or diagonal members would interfere with the aesthetics or functionality.
You can see these types of trusses are used in many different applications, like this, which we can see in the roadways:
So next time you are out and see one of these trusses in use, you can impress your friends when you tell them you are looking at a Vierendeel truss. Keep an eye out for them.
Bill Hoover – Design Professional
Gould Design, Inc.