2. FRAME STRUCTURES The frame structure is the most common choice of structure. These structures are composed of long elements (tubes, bars...) joined to each other at the ends. They are easy to design and build, lightweight and do not requiere much material; but it do not resist big loads or strong impacts.
4. SHELL STRUCTURES They are made of a thin outer layer of material that surrounds a volume. That volume can be empty space or can be filled with something that has no structural relevance. The forces are spread throughout the whole structure.
6. ARCH The Romans invented the arch. There are many types, but the semicircular arch is the most common. Its own weight is the main load, but it displaces the forces to the sides, so that a large space is left under the arch.
8. MIX AND MATCH Very often, different types of structures are combined and the combination is a more complex structure. For example, houses have brick walls which are part of mass structures and there are also colums and beams that are part of frame structures.
9. MASS STRUCTURES They are simply made of clump material, filling the body completely. They are made of low-quality materials. They are heavy, need much material and occupy large amounts of space. They are held in place by its own weight.
11. SUSPENSION STRUCTURES A suspension structure holds an element by cables that are held from the top of a tal column. The span is the space between one column and the next.
