November_1970 — Page 23

Fig. 1

Universal folding plate structural system

IN a novel concept for industrialised space structures recently developed in the United States a single component may be standardised for mass produc- tion without leading to standardised structures. The identical components may be joined in many different per- mutations to form an unprecedented variety of spans, plans, shapes and sections.

The Universal Folded Plate (UFP) System belongs to the family of ad- vanced space structures, which main- tain a three dimensional, or spatial equilibrium of external and internal forces, as opposed to the two dimen- sional post-and-beam, frame and other conventional structures. Three dimen- sional stress distribution permits more economical use of materials and it also increases safety against collapse, be- cause space structures can survive local failure of the individual members through redistribution of stresses. Space structures are eminently suited for industrialised prefabrication through which substantial savings can be made in manufacturing and site labour.

The basic UFP component is shap- ed like a diamond (rhombus) folded along its longer diagonal (Fig. 1) and connected along its four edges to iden- tical components. Because of their economical use of materials and ease of prefabrication, various designs for folded diamonds have been proposed in the past. However all these were limited to shapes with circular cross

Far East BUILDER, November 1970

sections, either cylindrical or spherical, and therefore from a given set of iden- tical components only a single size structure with a given radius could be built.

The UFP system is based on two discoveries: by using a new joint technique folded diamond com- ponents can be connected together in reverse as well as identical fold posi- tions; by optionally reversing some of the component's fold positions, a vir- tually limitless variety of new space structures can be assembled from iden- tical components.

Under these new geometric prin- ciples, the cylindrical assembly can be divided into smaller sub-assemblies of four interconnecting folded diamonds (Fig. 2) in which all four components are in identical fold positions and their long fold lines (valleys) lie in parallel vertical planes. It is therefore a paral

Fig. 2

Fig. 4

lel sub-assembly, as used in previous concepts of space structures.

Now completely new shapes may be created by reversing one (Fig. 3) or two (Fig. 4) of the four components. If two components are reversed, the sub- assemblies become straight ones, which no longer approximate a curva- ture, while the sub-assembly with one component reversed can be used as a transition between curved and straight sub-assemblies. A variety of cross sec- tions may be erected over rectangular ground plans using those three UFP sub-assemblies (Fig. 5 & 6).

For circular or polygonal ground plans new radial sub-assemblies (Fig. 7) have been found, in which the long fold lines intersect in pairs. Their structural assemblies may have a flat roof (Fig. 8) or the shape of a poly- gonal pyramid (Fig. 9). The latter pos- sesses a dimensional flexibility not

Fig. 3

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