The simplest form of space frame is a horizontal slab of interlocking square pyramids and tetrahedra built from aluminium or tubular steel struts. In many ways this looks like the horizontal jib of a tower crane repeated many times to make it wider. A stronger form is composed of interlocking tetrahedra in which all the struts have unit length. More technically this is referred to as an isotropic vector matrix or in a single unit width an octet truss. More complex variations change the lengths of the struts to curve the overall structure or may incorporate other geometrical shapes.
Space frames are typically designed, using a rigidity matrix. The special characteristic of the stiffness matrix in an architectural space frame is the independence of the angular factors. If the joints are sufficiently rigid, the angular deflections can be neglected, simplifying the calculations.
Architectural Advantages of Space Structures
- The unique simplicity and beauty of space frame structures in the architecture of the regular form of space structures is architecturally attractive, beautiful, and precious and this is why many architects exhibit space frames in halls, community centers, etc. and in many cases they even use space structures in building facades.
- Great flexibility in terms of architecture, using repeated seemingly identical geometric shapes. We could create different geometric shapes in accordance with various architectural designs, design, and produce the architect’s desired configuration. Common architectural shapes include flat shape, arc, barrel vaults, dome, umbrella, pyramid, sine, etc.
- No need to use false ceiling in space frame structures. The beautiful view of double-layer networks in space structures, appearing as repeated geometric shapes, provides a pleasing outlook which is architecturally precious and this is why a large number of architects do not employ false ceilings but space frames in community centers, mosques, airports, etc.
- The possibility of attaching several pendants from the ceiling of a space frame. Considering high load bearing capacity as well as numerous nodes at regular intervals, it provides the possibility of design maneuver to connect several pendants at any desired point, thereby creating unique (interior) architectural works.
- The possibility of extending space structures with a minimal change in the former structure due to “optionality of restraints order” in this type of structure – Increasing / decreasing the surface area of an implemented space structure from any side and in any way while keeping the former structure and following design tips is possible with a minimal cost. This unique capacity of space structures provides architects and employers with a great possibility in design and arrangement of development plans. This feature is found in no any other structure.
- An appropriate structure for lighting. Predefined points on space structures (structure nodes) along with the possibility of attaching spotlights or other light sources on any point of the generated surface area makes the setting beautiful and suitable for lighting and decoration.
- Space saving. The space between the layers of space structures provides a good place for pass of electrical, mechanical, thermal, and cryogenic and other structural facilities; in addition, numerous nodes of a space structure supply the required restraint for passing of these facility communication networks at no extra cost and minimize their visibility.
- A high safety factor. Designing a safe, beautiful, and stable structure is an important parameter for every architect. Since space structures have unique features, not many structures are comparable to them.