9 Going on with the unfolding process for the truss: finite element analysis

When you use nicely shaped triangles, the triangles naturally get smaller where the area of the truss gets tighter over the side arches. This has the feature that where the triangles get smaller towards the bottom, the shorter members and tighter mesh correspond to the zone with the biggest flow of forces. The arch members this force a geometry which helps the structure in a natural way.

We now realized that as a whole the modified truss was working in an entirely unexpected way. The arch and struts were all together, working as a kind of tension network which resists the spreading of the rafter beams.
This was a highly unusual design, previously unknown to either of us. The three-arch arrangement which originally arose in response to the spatial configuration of the dining hall had finally been resolved in a form where this particular shape draws its structural strength from a novel way of working through a tension network arch. The oddity of the original configuration, caused by centers in the dining hall, had become a virtue in an entirely new structural design.

#book/The Nature of Order/3 A Vision of a Living World/6 Positive space in engineering structure and geometry#