Structural Forms

Stability guarantee is based on statical principles clasified in:
 * 1) Basic statical principles: they opmize the materials behavior which are affected by loads, they are the traction, compression and cut.
 * 2) Complex statical principles: these are the combinations of the last ones.

Structural System Classification
2.  Arcs: the are structures used to support compression efforts. They are used in big and smal spans.
 * 1) Wires: they are flexible structures, this flexibility is given by the slight transversal section compared with the total lenght of the system. These materials have a minuscule flexion resistance, so the loads is divided out and de efforts become only tractional. This implies a changing in material form. The usual forms are:
 * Funicular polygon: when in the wire is appllicated a puntual load.
 * Parabola: when in the wire is applied a divided out load over its length.
 * Catenary: is the wire form because of its own weight.

3.  Sheets: the are used to support traction and compression efforts.

4.  Plates:  they are used to transmit concentrate loads to all the structure, so the loads are distributed over their surface.

5.  Membranes: they are similar to the plates but they are thiner, so they are able to transmit only tractional efforts.

6. Shells: they are structures which resistance

owns to their form depending on which loads are located.