what are trusses?

Answer 1

In architecture and structural engineering, a truss is a static structure consisting of straight slender members inter-connected at joints into triangular units.


Truss bridge for a single track railway, converted to pedestrian use and pipeline supportContents

History about it:

The earliest trusses were made out of timber (wood). The ancient Greeks used truss construction for their dwellings. In 1570 Andrea Palladio published I Quattro Libri dell'Architettura, which contained instructions for wooden trussed bridges.



Statics of trusses:

The central vertical member stabilizes the upper compression member, preventing it from buckling. If the top member is sufficiently stiff then this vertical element may be eliminated. If the lower chord is sufficiently resistant to bending and shear, the outer vertical elements may be eliminated. The inclusion of the elements shown is largely an engineering decision based upon economics, being a balance between the costs of raw materials, off-site fabrication, component transportation, on-site erection, the availability of machinery and the cost of labor. In other cases the appearance of the structure may take on greater importance and so influence the design decisions beyond mere matters of economics. Modern materials such as prestressed concrete and fabrication methods, such as automated welding, have significantly influenced the design of modern bridges.

Answer 2

Trusses are like a very large beam, with much of the web removed. The thing that distinguishes a truss is that they are modeled as if every member resists only axial stresses. That makes them easy to analize.

There are three main elements in a truss. The top chord, bottom chord and diagonals. The top and bottom chord act like flanges on a beam and resist bending moment, which is maximum in the middle of the span. The top chord is in compression, while the bottom chord is in tension. The further the chords are away from each other, the more moment is resisted.

The diagonals resist shear and are the maximum at each end of the span.

Answer 3

trusses are a combo of roof and ceiling supports used in building homes. they are made up of ceiling Joice uprights and rafters. you can buy them prefabricated or build them your self and install them whole. when installed, they give you the roof pitch, overhang and ceiling. gable end trusses are built a little different so that you can put decking on the outside of the house.

Answer 4

They are the vertical suports found in your roof. http://en.wikipedia.org/wiki/Truss

Answer 5

wooded beams