Basic rules and understanding of language application

In collaboration, a structural language of symbols is applied on a form model of conceptual elements. These elements are conceptual, as they do not represent specific structural solutions or a specific structural typology: each conceptual element represents a range of structural typologies and thus also a range of design solutions. The representation of each conceptual element in structural design is based on its general architectural expression. For example, a rectangular surface can represent a conceptual element for a truss-girder typology with a rectangular outline, or a rectangular Vierendeel-girder

typology. (In engineering science, such girders would commonly be presented through the axes of their different members.)

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Figure 7-18. A conceptual element representing different structural typologies.

A conceptual element can be further detailed through a combination of other conceptual elements, giving it a more specific expression. For example, a rectangular surface can be developed into a combination of lines that represent the axes of the various members of a truss-girder. This further refinement limits the possible structural design solutions towards this more detailed architectural expression. Still, because each line represents a conceptual element with a linear expression, it does more than merely representing the design solution of a profile with a constant cross-section (e.g. a hollow tube); the conceptual line can also represent, for example, a three-dimensional lattice-girder with a linear (architectural) expression.

Figure 7-19. Conceptual line as part of a refined conceptual element.

7. A structural language for conceptual design

145 This concept of representing an element through its architectural expression rather than the axis of a structural typology seems to be less common among engineers. Still, it should not be too uncommon in the engineering sciences, where the conceptual representation of a structural element through one axis can still signify that the element consists of several other elements (as for example a lattice-girder).

In architectural design, this rather abstract representation of an element through a general expression is common, as is alternating between more detailed expressions and the initial conceptual element during a design process (i.e. scaling up and scaling down, cf. Chapter 2.3).

By applying structural symbols to these conceptual elements derived from architectural design, structural and architectural design are brought together in one representation.

The new structural symbols applied to these conceptual representations are derived from the layers of structural order and structural dimensions.

The conceptual nature of these elements helps the engineer in designing on a more abstract level than through (more detailed) typologies, and supports a structural design process that explores various conceptual design propositions through a method of conceptual refinement and abstraction before entering the realm of typologies. (The proposed language provides for a more conceptual interpretation and investigation of structural design than current engineering language, which is developed for in-depth structural analysis.)

This language articulates and supports a design process in which an engi-neer proposes and evaluates various choices for possible structural elements and their composition, supports, loads and load paths, as well as element connections and the structural functions of the various elements. These design choices have an important impact on the range of possible design solutions, and delineate an exploration of structural space and form later in the design process through structural calculations and scientific optimization processes.

Using the proposed language to express conceptual design propositions makes the engineer’s design decisions more apparent for negotiation with an

architect.

Together the layer of order and the layer of function present a narrative of how loads follow paths through various structural elements to the supports, and how each element transfers these loads to enable the structure to function as a system. These load paths and the functions of the different elements are designed by the structural engineer. Both layers express the designing engi-neer’s intention. (A structural engineer in the role of designer, instead of calculator of structures, can be even better understood when each function of a

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structural element is seen as a process that transfers a load from input to output. A structure is then a system of processes by which the outputs of each element become inputs for the next element. And thus an engineer is primarily a designer of such systems of processes rather than a calculator. This is more extensively explained in the appendix of this thesis.)

The structural dimensions layer filters structural functions through the consequences these functions have on the structural form of an element.

Through this expression of form that lies within the layer of structural dimensions, this layer generates a structural design proposition that is related to architectural design.

Both layers of order and dimensions contain an essential story of the structural logic of a conceptual design proposition. They provide necessary design characteristics of an engineer’s conceptual design proposition, enabling to alter the given structural form model according to the intended conceptual design proposition.

For each structural element, the link between the layer of dimensions and the design possibilities provides for a wide range of design solutions for a specific proposition made by the engineer. This knowledge can then be used for negotiation between architect and structural engineer for the further development of the collaborative design.