04-04-2011, 09:29 PM
No, they just rebuilt an onager and built the phisycal model afetr it.
It was most usefull to us because of their finding regarding the "cilinder of material"
What we need to think about when build torsion and tension artillery is on Force.
Everything will reduce itself to Force, what can the material cope with, what do we need.
Torsion artillery has the huge advantage of "calibrating" the forçe you want to use. You do that like the Greeks and Romans found out empiricly (and that Hart and Lewis proved cientificly) you increase the D of the washers, which by their reasoning also increased the distance between washers. Since a cilinder volume is base x height this will wield an exponential increase in Force.
But although they could increase the Engine Force by simply making larger washers, then you have other limiting factors such as the break strain of the arms, and the break strain of the hole carriers.
What we've found, not only by running Computer simulations but also by firing on the field, is that the arms will break first than anything when they are made of wood.
From here we can extrapolate that being the arm wood fibers the first to give, due to elastic forces demanded of them, a tension engine without some serious metal reinforcements (or laminated metal arms as a whole)would be not as strong simply because of material limitations.
When da Vinci planed his "giant crossbow" he planned composite arms, if in the classical era you could build such wood/wood composites or wood/metal composites, it is likelly that Tension would give Torsion a run for its money.
Something we wouldn't mind doing if we could get a grant (or just acess to some extensometers, tension meters and ultimate stress/strain machines - but Eng. School is long gone.)
With the known technology level I'd say that from a builder POW, torsion would be far easier, an ultimately stronger.
It was most usefull to us because of their finding regarding the "cilinder of material"
What we need to think about when build torsion and tension artillery is on Force.
Everything will reduce itself to Force, what can the material cope with, what do we need.
Torsion artillery has the huge advantage of "calibrating" the forçe you want to use. You do that like the Greeks and Romans found out empiricly (and that Hart and Lewis proved cientificly) you increase the D of the washers, which by their reasoning also increased the distance between washers. Since a cilinder volume is base x height this will wield an exponential increase in Force.
But although they could increase the Engine Force by simply making larger washers, then you have other limiting factors such as the break strain of the arms, and the break strain of the hole carriers.
What we've found, not only by running Computer simulations but also by firing on the field, is that the arms will break first than anything when they are made of wood.
From here we can extrapolate that being the arm wood fibers the first to give, due to elastic forces demanded of them, a tension engine without some serious metal reinforcements (or laminated metal arms as a whole)would be not as strong simply because of material limitations.
When da Vinci planed his "giant crossbow" he planned composite arms, if in the classical era you could build such wood/wood composites or wood/metal composites, it is likelly that Tension would give Torsion a run for its money.
Something we wouldn't mind doing if we could get a grant (or just acess to some extensometers, tension meters and ultimate stress/strain machines - but Eng. School is long gone.)
With the known technology level I'd say that from a builder POW, torsion would be far easier, an ultimately stronger.
