Metals: Elements
Plates, Sticks and Joints
Metals are so often used as structural materials that their various production processes and physical properties are taken for granted. It is important to understand the material so that we may make appropriate use of it. This will become more important as the raw materials be scarcer and the energy costs of their production become more significant.
The most important properties of metals are their relatively high strength and stiffness. For instance, common structural steel, which is by any standards a relatively low quality material, has at least ten times the compressive strength of concrete or masonry, and also has ten times the material stiffness or Young's modulus. This strength and stiffness allows us to create the most visually slender structural forms of any material.
Typically metals are available as 'sticks' or plates of varying profiles and lengths. The standardised shapes of these rolled profiles are then made to work in our designs. However, some metals are available as extruded form, which gives us the opportunity to optimise the structural section to resist the applied forces and to shape profiles for a particular use.
Joining metal components together is an easy task. Bolted or welded connections can be made as strong as the parent components, allowing small and unobtrusive junctions to be formed.
For us, one of the most interesting areas of development is that of cast metals. The technology has advanced in recent years so that components may be cast economically that have a high structural integrity, and that can be formed into almost any profile. We have found it possible to use the flexibility of shape to work for us by creating structurally optimised components, that can then be given interlocking profiles, making connections elegant and cheap.
Particular metals, and their alloys, have specific properties which will determine their use on projects. Steel is the stiffest and the strongest metal, generating the most slender forms. Bright steel is a particular grade which has a fine grain, making it suitable for highly machined components with sharp edges. Aluminium has the advantages of lightness, durability, and self finish, and is particularly suitable for casting and extruding complex shapes. We have also used copper based alloys such as brass and bronze, that have fine grain and strength, and that can also provide a cultural gravitas.
