Most people have, to some extent, an understanding of what structure is without necessarily realising it. In the most general sense structure could be defined as something with a purposeful arrangement or in other words something that exists in the form that it does for a reason.
For instance, we require linguistic structure, teachers might say grammar, to explain our thoughts and to convey abstract ideas. Grammar brings specificity to our words, which would otherwise lack clarity and would be robbed of depth and meaning.
It follows that structure necessarily places constraints on the use of language. That said, it would be a mistake to think that structure is therefore restrictive or in anyway stifles creativity. In fact the opposite is true. None other than Picasso is reported to have said.
“Learn the rules like a pro so you can break them like an artist”
I don’t think this is a trite statement at all. Picasso did not break rules because he did not understand or respect them. He had a considerable mastery of the rules, which he then used to create new ones.
Structure therefore has the potential to rise above mere function. It can be used in clever ways to delight, surprise and amuse. For example, there is unquestionably an elegant structure to Shakespeare’s sonnets and Beethoven’s symphonies. There is structure in the rhythms of Martin Luther King’s rhetoric and in the brush strokes of a Di Vinci painting.
Nevertheless, while an elegant structure has the power to uplift and delight, it often does so with a lightness and subtlety that renders it unnoticed. The viewer sees or hears the masterpiece while failing to notice the framework on which the master has constructed it. Conversely, we can tell straight away when structure is absent. There is no joy in art or literature that lacks structure.
Structure in the sense of design and construction is no different. There is not a work of prize wining architecture that does not require a carefully considered structure. Structures of this sort do not convey words, instead they convey an engineer’s ideas and concepts about the articulation of weight and force. A structure that delights is therefore one that displays an engineer’s thoughts with the lightness of a sonnet or the stroke of a brush. It gives the sense that carrying load is effortless.
The untrained eye may not appreciate how this has been done, however there is still an innate sense of structure in all of us. We recoil from stepping on a glass floor, are wary of a creaking beam and stand clear of a leaning wall. We do this because we have learned to recognise the danger of brittle materials; the sound of excessive strain; and the potential consequences of instability. Contained within these very human responses is in fact the essence of building structures.
Every structure is made of a material. Some materials are brittle and will fracture suddenly, others are ductile and will deform and yield. There are malleable materials that can be shaped by working and others which must be cast in formers. There are materials which resist corrosion or fire and others that corrode, decay and soften.
There are homogenous materials that have consistent properties throughout, while others retain the flaws nature has gifted them.
While every structure is made of materials those materials must respond to the actions, which are imposed on them. They might be asked to bend, buckle, stretch, squash, shear or vibrate due to externally applied loads. They might also expand or contract due to temperature or moisture variations. Depending on how long an action is applied a material’s response may change. This is true in general, but is particularly true of certain soils on which structures are founded or which they must restrain.
Irrespective of the materials from which they are made and the actions they must resist all structures must have a form that is inherently stable. A structure’s various components must be joined in such as way that they are in equilibrium and will not topple.
The purpose of a structure may vary, but these principles do not. A structure may be required to span a valley so that people can cross or it may be required to enclose a space for people to watch sport or perhaps it might be required to provide a place to live and work, which is safe from earthquakes or floods.
It is of course the role of a structural engineer to find a purposeful structural arrangement, which is capable of fulfilling the project requirements. To do this engineers apply their knowledge of materials, actions, equilibrium and much else besides.
Though this is a highly rational process, when it is done well the endeavour is no less creative than any work of art and the results can be just as spectacular. Indeed the best structures combine both function and sculpture.