elastegrity?

This text is the contents of a paper I submitted to IASS2015.org

 

What can the matter be?

 

 

*Stewart MACPHERSON

3 Bosville Terrace,

Portree.

Isle of Skye.

Scotland.

IV519DG

portreekid@btinternet.com

 

 

 

Abstract uStructures - building structures with elastic strain energy. Classical mechanics is Load (UTS), Elastic Strain Energy is, well, energy. The question we need to be asking is "Can matter provide this energy?"

 

Keywords elastic strain energy, vortex/torsion energy, energy from matter, DNA helix, quantum energy, batteryHelix, uStructures, batteryHypar, lattice shell.

 

Introduction This paper will introduce the concept of structures built with elastic strain energy. These are referred to in the text as 'uStructures'. The paper will introduce the 'batteryHelix' – the first uStructure. There are other types to consider, such as the batteryHypar, but we shall for the moment be considering the first evocation of uSructures.

 

In the process we shall be considering approaches to classical mechanics, parametric modeling in software and the implications and conventions of 'thinking' in a liner fashion as a necessary prelude to setting the scene for introduction of uStructures.

 

The author will suggest that even although in recent times there has been a sea-change in thinking within the design of shell and space-frame structures we also need to free ourselves from the shackles of referencing these structures in an out of date register. Technology has allowed us to break free from conventional ideas of what structure is, or can be, but we must be careful to choose the right underlying language of support.

 

Now that we have the new set of cloths, is it not time to update the machinery of production. Is it still sufficient to talk of Loads, Grids, Mesh, Tension and Compression and so on in the context of these highly elastic and mold-able modern computer-controlled shapes and structures, we shall see.

 

MainText When we open our parametric modeling software we are given 4 screens, 3 dimensions and one overview. We are also given an underlying mesh structure to start from and with the help of precision co-ordinates we begin to build our frames, tweaking and stretching and extruding. We accept this convention because it makes sense, how else would we be able to start, what reference points could we start with, we have to start somewhere, right. But wait, what do we as engineers and architects think of when we think of a mesh? In the real world, if a mesh or lattice of any kind is constructed - lets say of wood - it is obvious that its intersections must be fixed, nailed, screwed, etc., otherwise it would collapse in a match-wood heap. In other words a mesh, lattice, frame, needs to be secured, and pretty well secured to maintain its essence.

 

So, now we all accept this convention, so much so that we have logically incorporated it into computers, thereby imposing our preconceptions on a technology that has thus far enabled us to imagine and build some of the most vivid and poetic structures ever conceived, despite having handy-capped its potential to help us discover even more wonderful structures, by restricting it to our understanding.

 

By insisting the mesh be the starting point in parametric modeling we will naturally project our assumptions about and interpret our understanding of how a mesh works, in the real world. The one has reinforced the other, in an iterative fashion. This thinking seems to underline how important and deep routed our subconscious linear approach is to a fundamental appreciation of structure. We have already decided, before we start. It is as infused in our psyche as marmalade sandwiches, we never give it a minutes thought.

 

Understand, it is not that the inception of our designs on mesh is the problem, for as we all know we must provide some meaningful foundation, we must start from somewhere. It is only that by using a mesh as the starting point we reinforce our already preconceived notions about this commonly familiar structure. We just take it as given, whether from computer to real-world or vice-verse.

 

Now, although, even before the advent of parametric modeling software, designers have given us beautiful tensegrity, reciprocal and space-frame structures of exquisite strength and complexity, we may still be thinking and analyzing them using a language of the past. Because of our widely regarded and culturally accepted affinity for the established laws of mechanics we still imagine these structures through a mind-set of forces, tension, compression, etc., or through the idea of weight or mass, whether in tension or compression; Newtonian mechanics. Perhaps, even now it is still customary to 'understand' these structures from a conventional perspective, however much engineering has sought to instill best practice in its practitioners. Equally, we can all agree how institutional thinking can be subconsciously restrictive.

 

Mass, matter, 'structures', are analyzed through an accepted convention of UTS and an appreciation of discrete stresses and strains in a member, in twisting, bending, compression, tension, etc. Heretic-ally, uStructures do not consider forces in this way. Rather, uStructures make use of the energy from within matter (materials) to provide the mechanism for support. They do not concern themselves with action and reaction in the conventional sense, but reorganize/redistribute strong energy, one of the fundamental 4 forms of universal energy. There may well be stresses and strains of a member at the molecular level, indeed how could there not be, but these are secondary to the mechanisms of pure strong energy. We are taking energy from matter and using it as our primary means of supporting the uStructure.

 

Energy has no mass, or at least only a negligible amount. Matter has mass. In the batteryHelix there is no external energy. The structure is self-contained. It takes its energy from the material, matter, of the external lattice of the structure. It achieves this by a trade-off of the contained energy of materials of differing resilience. It is the familiar concept of elastic strain energy drawn from the dissimilar resilience's of very ordinary wood.

 

Don't panic this is not voodoo, we have understood resilience since antiquity and fracture mechanics is nothing new. A boy child's right of passage is to make a bow and strain it into shape with a piece of twine, energy underlies our understanding of fracture mechanics. However, we have always been taught that energy, especially 'fracture' energy is to be avoided, why would an engineer encourage energy to propagate unchecked in his/her structures lest they fracture. Insanity, surely? Well, yes and no…..

 

If we allow energy to develop out of control then the result will be fairly predicable, but the batteryHelix's form only induces the required amount of strain energy, fractional less than the available amount. Because each piece of the lattice is of equal length the whole structure shares the strain democratically, it is a 'tight drum'. BatteryHelix requires no ties, trusses or buttresses to support it. Resilience, reciprocal repulsion, torsion and bending under strain, resonate in harmony, if we could hear it, it would probably sound like Paul Robson from up-stage...

 

Workshops are toying with this principle of repulsion and resilience, there are good examples of these inquiries and it should not be long before we understand that we may be able to ditch the lattice all-together and simply focus on the skin. Professor Jun Sato of Tokyo University is already working along these lines with his 'Moom tensegritic membrane structure'[1] This structure roughly outlines the thrust forces of the batteryHelix in membrane form, but it is not a drum skin, it comes from the tradition of ties and struts, elements of mass, load and weight, despite its lightness, however it does anticipate farther ambitions. batteryHelix's sprung and taught drum effect also permits it to act like a cantilevered beam, by supporting it at only one end.

 

Other features of batteryHelix are that it requires no mechanical fixings, it is simply pinned loosely and allowed to adjust to its optimum position. Interestingly, although it is pinned in a lattice formation there appears to be very little force transferred through these connections? Similarly, the author is aware [this may sound contradictory, in the light of earlier remarks] ties can indeed be incorporated, although again not in the usual arrangement of a lattice structure? These ties should be so positioned as to mimic the 'solid' effects of the reciprocating struts. What is meant here is that the devise of ultimate support, the strut of higher resilience, can be replaced (removed), replacing a conventionally understood compression member with a tension member, without any noticeable side-effects. On first sight there is what would appear to be some degree of similarity to Tensegritic structures, as hinted at above. Qualitatively this is worth explanation.

 

In Kenneth Snelson's models we can clearly see that the ties and struts do not meet at any nodes. In fact there are no nodes as such. And, since there are negligible energies transferred through the pinned connections of the batteryHelix (these are mainly locators for the overall form) we can postulate that the whole frame is somehow 'electrified' by the induction of this contained system of reciprocal energies.

 

Can we make one other claim, since batteryHelix is in effect a battery which stores potential energy, could we not therefore utilize other forms of energy. Could we not electrify a conducting material instead of using wood. Or, perhaps we could use magnetism? Can we use photons, what other resonant frequencies might we use?

 

In Biophysics we now understand that our olfactory senses may well function through acoustic frequencies. With inspiration from quantum physics we now believe that the common robin navigates by a combination of magnetic fields interacting with photons entering its eyes, rather than purely on magnetic fields as was commonly understood. [3] Whatever the outcomes, few can deny we are entering exiting times. Whether batteryHelix will play its part in these endeavors remains to be seen, we can only imagine.

 

Jay Harman the inventor of the Lilly Impeller [2] makes the claim that energy does not travel in straight lines nor does it travel in a plane. It can do, but it requires some effort. His claim is that it is a vortex/torsion energy. Would it not be better to allow nature to be, to do its thing, rather than constraining it as we have done in the past. J. E. Gordon [4] in his wonderful book on structures illustrates this beautifully with his analysis of the Chinese Junk sail and the modern sailing yacht. The batteryHelix is essentially a series of DNA Helix structures, bending, twisting and stretching elastically, complementing Jay Harman's assertions.

 

Traditionalist will scarcely believe the claims in this paper but if the above turns out to be creditable (or in-creditable) structuralist need to be investigating their potential. The author has worked on these forms since the summer of 2013, virtually continuously, focusing, model-making, experimenting, it has been a wonderful journey now it is time to share these experiences. There are more structures to discover such as the batteryHypar, which requires considerably less effort and cost to construct.

 

 

 

This journey started with a question, how tricky is it to weave with wood? The understanding of weft and weave of garments is a familiar practice to us all, the method involves weft and weave at right-angles. If we try this with wood (bamboo sticks) it is quite tricky to accomplish successfully without concentration. If one accidentally nudges a piece/stick the arrangement can go out of line pretty quickly and it can be frustrating, because again we are trying to force the stick to behave under certain constraints, constraints that it does not want to perform. In other words, it wants to twist and turn out of a constricting arrangement and find its own equilibrium, and it soon becomes a struggle to 'hold it down'. Why do we do that…

 

Perhaps because we are trying to arrive at the conclusion of our task before we experience the journey towards it. We are influenced again by that so-called intuitive understanding of what it is we 'think' we are trying to achieve. How many times does this kind of thing happen in our lives, and we hardly ever seem to notice the contradiction. We are guided by these conventions almost in autopilot, and rarely do we truly 'observe' and take in what it is we are doing. This is not an uncommon comment on us as humans, it has been said many times before but, its like we are sleep-walking through life. Conventional thinking is limiting, so lets not do it please…

 

So we let the sticks decide their own configuration, what do we find, what does our experiment show us, what do we see in front of our eyes? This is what the author saw one day, back in the middle of 2013. It was energy, right there, where the struggle to hold-down this straining force accidentally released it. It was the first wow moment, for the author, it was a light-bulb moment, Eureka, elastic strain energy!?

 

Try it yourselves. Take 6 sticks (bamboo if you can) and arrange them by weaving them in and out, like you would if you were working a loom. You should have a square divided up into four smaller squares. Now you see if you can hold them down. If they are not perfectly square to each other they will not sit 'comfortably'. That's OK, because they need to be off-center for this purpose. When you get good at it, you begin to see the saddle shape emerge – yes the Hyperbolic Paraboloid, the dynamic form loved by architects the world over. But this one is different. We didn't need elaborate form-work to 'see' it, all that was required was elastic strain energy!? Second light-bulb moment...

 

This happens because of repulsion energy, widely understood as reciprocal forces. The bamboo is elastically resilient [enough] to allow the sticks to push up, forming the uStructure. From knitting, we get uStructures. Weaving; to reciprocal forces; to elastic strain energy; to uStructures. In that sequence. Simple.

 

Yet it would have been impossible to observe this process, had the author attempted this with parametric software because elastic strain energy is a living force. It happens in the hear and now, no computer can mimic that, it's just too chaotic. However, now that we understand the dynamics of these forces how can we possibly replicate this in software that has a 'rigid' mesh as its canvas? This could be our next great challenge. Somebody will do it, sooner rather than latter...humm..

Having got thus far, the next step was to find a form that we are all accustomed to, which turned out to be the batteryHelix. Remember, we are still on our journey, nothing is set in stone, we are free from convention. So, batteryHelix was born out of this process of build, observe, build again. Each time trying different permutations until the first that revealed itself was batteryHelix. Recall batteryHypar was an accident.

 

Lets challenge another convention. Most structuralist, when working with reciprocal forms rely on the ability of members to span in polygon, hexagon, etc. configurations. Essentially trying to span a gap or area with members of shorter length than that which would span the gap in one member. Conventionally saving money, reducing head-height etc. So that even as we have described elastic strain energy from reciprocal actions, reciprocal structuralists still think in terms of tension and compression loads – again mass, weight, load, tension, but rarely appreciate the possibility that strong energy can provide an equally elegant alternative. Traditionalist will constrain the member to provide load-carrying capacity, thinking in terms of UTS, instead of turning the problem on its head (as it were) and allowing the member to push up, rather than load down.

 

In the batteryHelix this pushing up action (strong energy) is only a fraction of the available energy in the system. Of course there is a logical limit to the amount therein but by how much, a factor of 2, 3, 4….? Conditions depend on how resilient the frame is. A bamboo model can illustrate this strong energy very ably, because it is very resilient, having a low Young's Modulus.

 

Lets recap then. So the author has attacked just about every accepted model of engineering, he has castigated convention, pilloried linear thought and destroyed a multimillion-pound computer industry without which we would not have gained so much. Yes, er, sorry about that.

 

Remember, none of this knowledge can really be said to be a revelation, in light of the fact that (as my granny would say) 'there's nothing new under the sun'. Of course she's right, there is nothing new under the sun. Its just the way we see it.

 

 

 

[1] Prof. Sato. Jun. MOOM tensegritic membrane structure. https://www.youtube.com/watch?v=S-rZK9luRFw

 

[2] Harman. Jay. Lily Impeller.

https://www.youtube.com/watch?v=by0JhirtO-0

 

[3] Quantum Robin.

http://www.theguardian.com/science/2014/oct/26/youre-powered-by-quantum mechanics-biology

 

[4] Gordon JE. Structures: or Why things don't fall down. Penguin 1978