Why most of bridges uses triangles?

Question

Why most of bridges uses triangles?

Answer 1

Triangles are very strong

Answer 2

triangles are the strongest forms in existance

Answer 3

A triangle is the strongest shape there is, because every vertex of a triangle is connected to every other vertex.

You can see this for yourself if you build simple models with something fairly flimsy such as drinking straws and adhesive tape.  Something like a square can collapse easily; but if you add a diagonal bracing member, forming two triangles, it becomes much stronger.

Answer 4

All the 3 members (sides) of the triangles are loaded. In other words, all the 3 members provide strength to the triangular structure (truss). For structures with more members this may not be true, as some members may not be loaded and do not provide any strength to the structure.

Also, a triangular shape is very stiff and retains its shape. If you make a structure with 4 members you can change the shape by changing the angles between different sides.

So, triangles are used for 2 reasons:

1. Strength contributions from all members

2. High stiffness

Answer 5

triangles are similar to truss,

easy to design, economical.

Answer 6

A triangle displaces the weight evenly, so the entire structure is more sturdy throughout and more weight can be placed upon the triangled area.

Answer 7

Triangles? I'm assuming you re referring to the truss design that appears similar to a triangle. The design is capable of carrying very heavy dead loads (pre-stressed concrete, rebar,steel beams etc etc) as well as live loads (ie, trucks, cars, rain, snow, people). It also allows for seismic loads. In comparison to a suspension bridge i would think it is also very cost efficient.

  There are forces, stresses and deformations produced in a structural component by the applied loads, a vertical truss, which is nothing more than a braced frame is designed to provide resistance to lateral loads and provides stability for the structural system.