what are Cables, Arches, Trusses, Beams, Surface; Membranes, plates and shells?
Cables are usually flexible and carry their loads in tension, cables are commonly used to support bridges and building roofs. When we use cables fro these purposes , the cable has an advantage over the beam and the truss, specially for spans that are greater than 46m, because they are always in tension, cables will not become unstable and suddenly collapse, as may happen with beams or trusses. Arches achieves its strength in compression, since it has a reverse curvature to that of the cable. The arch must be rigid, however, in order to maintain its shape, and this results in secondary loadings involving shear and moment, which must be considered in its design. Arches are frequently used in bridge structures, dome roofs and for opening in masonry walls. Truss is a structure comprising one or more triangular units which are constructed with straight slender members whose ends are connected at joints. A plane truss is one where all the members and joints lie within a 2-dimensional plane,
