The space frame structures are strong, lightweight truss structures consisting of interlocking struts arranged in a geometric pattern. This is a new technology in architecture and construction. Space frames can span large areas with little need for internal support.
The strength of the space frame structure is due to its inherent triangular stiffness and bending loads, which are transmitted as tensile and compressive loads along the length of each strut.
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Stability of Space Frame Structure
Space frames are usually designed using a stiffness matrix. A characteristic feature of the stiffness matrix in the architectural space frame is its independence from angular factors. If the connection is tight enough, the angular deviation is negligible, which simplifies the calculation.
When a force is applied to the blue node and there is no red bar, the behavior of the structure depends entirely on the bending stiffness of the blue node. If there is a red bar and the bending stiffness of the blue node is negligible compared to the contributed stiffness of the red bar, the system can ignore the angular coefficient and compute it using the stiffness matrix.
The simplest form of a space frame is a horizontal slab of square pyramids interconnected with tetrahedra made of aluminum or steel tubular studs. In many ways, this is like making the horizontal boom of a tower crane wider by repeating it several times. The stronger form consists of an interlocked tetrahedron with all struts in units of length. Technically this is called an isotropic vector matrix or octet farm in terms of unit width. More complex variants can change the length of the column to make the entire structure curved or include other geometries.
Advantages of Space Frame Structure
- The space frame structure is easy to transport, handle and stack.
- It provides an adjustable camber function.
- The quick installation or prefab components allow for very easy on-site installation.
- There is no need for purlin.
- It is more suitable for structures with irregular planes and sites.
- It is also suitable for structures with large spans.
- This provides excellent scattering at low altitudes.
- It gives very low deflection.
- Frame space structures also have maximum seismicity.
- The width to depth ratio is excellent.
- This ensures low shipping costs.
- Lightweight and structurally efficient.
- Concentrated loads are evenly distributed throughout the structure.
- Has very good acoustic properties
Cons
- Construction of space frame structures is limited to 40 feet when using reinforced concrete.
- The space frame surrounding the 3D plate structure is based on triangular stiffness and is usually composed of linear members that are subjected only to axial tension or compression.
- Some joints are relatively stiff due to bending or torsional effects, but this is negligible.