ARCHIMEDE INSTITUTE


Showing posts with label Physical Tests. Show all posts
Showing posts with label Physical Tests. Show all posts

IN BRIEF...

In 1980 our director designed a manufactured house that could be erected on the Canadian permafrost zones, one that would be raised to better resist the fierce winds and to avoid the potentially disastrous melting of the soil below it. To that end he joined forces with Placide Poulin and his manufacturing group to create Archimede Systems Inc., setting up a plant in eastern Québec. There Jacques designed presses to inject panels with high-grade insulating rigid foams. He chose the rhomboid geometry for strength, but also for the convenient manufacturing feature that all panels are nearly identical except for the openings. Before a few were erected in the Nunavik, the model caught on in the lower latitudes, thanks partly because of the high insulation values and the low price. Two years and $12M produced later, the houses were being built with little changes in the tropics; several of them were later hit by hurricanes Hugo, Frederic, David and a host of minor storms, all with little or no damage. They are still today the story of legends. But Archimede Systems Inc. had advertised the house as 'hurricane-proof' after conducting tests at the Laval University Civil Engineering wind tunnel in
Quebec City. Yet the theory was there already, for the strength and for the low wind drag factors of these dodecahedron shapes. This was no fluke. Neither was the earthquake resistance that was factored in at the onset of the Archimede program. Rhombic dodecahedron construction is notoriously resistive to horizontal shear in any direction. When raised on pillars that absorb the shocks, the deal is closed.
However, there was a fluke: twenty five years later, after the Indonesian tsunami, Poirier met some scientists confirming that this Arctic building solutions would be perfect for tsunami resistance. Actually it was almost perfect. Something small had to be invented. But that's a story better covered in the 'Tsunami' keyword.

THE PERFECT DEMOLITION SYSTEM

When a hurricane passes over a house, the first part of the transit has winds coming from a fixed direction, swirling in gusts and dragging a vibrating tail behind the house, especially if it is one with square corners. Think of the swirls behind a large semi on the highway. Materials and connectors are quickly loosened but might still hold together.
Then comes the restful eye with no winds at all, after a maximum velocity was attained near the eye. Think of 185 mph as was topped on our Sint Maarten condos!
Then comes the wall of pain: from the opposite direction new winds hit suddenly with a punch equal to those just before the eye. What was loosened is now detached or broken off, flying away to destroy other houses. Those winds are also a lot wetter, in most cases.
Think of you one bends things in either directions to break them. That's what a decent hurricane does. In some cases, the hurricane will travel very slowly, compounding the damages. Luis in Sint Maarten had the bad idea to shake and vibrate it's way through the island in 12 hours, enough to disable the island for tourism for almost three years!
And we had no damage to speak of, in spite of the fact that concrete block houses all around had to be demolished and rebuilt.
Satisfaction for us, as those years of design and wind-tunnel testing had finally paid off in a conclusive way. The weaker hurricanes like David and Frederick and even Hugo did not provide the proof we needed. We needed a monster and we got  it on the 5th of September 1995. I was there. Thanks Luis!
Jacques