PDA

View Full Version : Physics/Materials Science applied to gaming question



gooddragon1
2013-10-21, 06:07 AM
Horseless Headless Horsemann's Headtaker (http://wiki.teamfortress.com/wiki/Horseless_Headless_Horsemann%27s_Headtaker)
http://media.steampowered.com/apps/440/icons/c_headtaker_large.1be5482934b57336909ebe3e19c50a5c d30eed87.png

Would that axe run into problems from not being connected at the back if used repeatedly under real life physics? I've always wondered.

Sir Enigma
2013-10-21, 09:18 AM
Almost certainly - that open notch causes huge stress concentrations at the tip, as well as allowing it to flex (so it's subject to metal fatigue as well as straight-up fracture), meaning that a crack will develop there quite quickly and the top part will break off.

Jay R
2013-10-21, 09:27 AM
It only get stress if you hit with the top part of the edge. Since the sweet spot appears to be below that part, it won't take that stress very often, unless the wielder isn't very good with an axe.

But if it were my axe, I'd break the top off on purpose. It looks like it would balance better and be a better weapon (for me) if it were only the bottom part. That complete head looks too heavy and unwieldy.

gooddragon1
2013-10-21, 09:32 AM
Almost certainly - that open notch causes huge stress concentrations at the tip, as well as allowing it to flex (so it's subject to metal fatigue as well as straight-up fracture), meaning that a crack will develop there quite quickly and the top part will break off.

So, if you connected the back with metal about the width of the handle would that solve the problem?

Deathslayer7
2013-10-21, 10:41 AM
It would certainly help, but any metal blade with a hole in it will suffer in integrity no matter what. Because of the hole, you have increased stress concentrations on those parts that otherwise wouldn't be there had the blade been made solid.

That being said, if you still want the hole, use rounded edges. Rounded edges have less of a stress factor than squares or points.


http://www.efunda.com/designstandards/plastic_design/images/radius_stress1.gif

The picture shows the stress concentration factor for a metal rectangular plate with a hole in it. Stress depends on the radius of the hole with respect to how thick the plate is. The bigger the hole, the more stress you have. The bigger the thickness, the less stress you have.

gooddragon1
2013-10-21, 03:55 PM
Thanks for the responses so far.

If that axe was solid metal (including the handle and the areas where there are holes) would it be impossible to wield?

Crude representation attempt with mspaint
http://i32.photobucket.com/albums/d12/gooddragon1/h4_zps6c2c4ae2.png

Brother Oni
2013-10-21, 04:01 PM
Thanks for the responses so far.

If that axe was solid metal (including the handle and the areas where there are holes) would it be impossible to wield?

Crude representation attempt with mspaint
http://i32.photobucket.com/albums/d12/gooddragon1/h4_zps6c2c4ae2.png

It's be perfectly usable. Bearded axes (http://en.wikipedia.org/wiki/Long-bearded_axe) are of that approximate shape, although a two handed version usually has a longer haft.

warty goblin
2013-10-21, 08:33 PM
It's be perfectly usable. Bearded axes (http://en.wikipedia.org/wiki/Long-bearded_axe) are of that approximate shape, although a two handed version usually has a longer haft.

The kicker isn't the shape of the blade, so much as the thickness. I can't think many bearded axes were the majority of an inch thick over most of their blade. A modern wood axe gets close to that near the socket, and while they cut trees quite nicely, I wouldn't want to fight with one. And a woodaxe's blade is only maybe three inches long, not a foot.

Jay R
2013-10-21, 08:48 PM
I suspect that it would probably be too heavy for me to wield. YMMV.

JustSomeGuy
2013-10-22, 06:12 AM
Guys: How feasible would it be to have that axe (minus the blatant lack of maintenance), but take the top bit off so the lower 'jaw' curve becomes the top, leading out to the point where it curently is more or less - it looks to me like most of the weight would be below the 'chop' strike zone, so balance would possibly not be an issue, but you would also have a sort of sword edge point leading out for stabby/slashy-draw stuff. Would this work? Scaled to an appropriate size so overall weight isn't an issue, obviously.

Traab
2013-10-22, 09:00 AM
The filled in picture makes it look closer to a bardiche than anything.

http://www.aceros-de-hispania.com/image/paul-chen-swords/187polish-bardiche-axe/187polish-bardiche-axe.JPG

Heliomance
2013-10-22, 09:06 AM
I'm not convinced it would bend, assuming good enough craftsmanship. If you imagine taking off the top portion from the hinge of the jaw parallel with the blade, you'd end up with an axe with essentially a sword blade sticking up from the top. And swords are a lot longer than that, and not known for bending and breaking unless they're shoddily made.

Jay R
2013-10-22, 09:57 AM
Swords and axes are made and wielded differently. An axe is a mass weapon, not a slicing weapon, and can take more power shots.

If you made a swordblade out of the top of the axe, the lower part of the weapon still has lots of mass, and when the swordblade hits something, the axehead will have a lot of momentum, so it will have greater stress than a sword usually gets.

Furthermore, the mass will make the swordblade a poor choice for slashing.

If I owned this, and expected to have to wield it, I would break off the top half and make a straightforward axe out of it. It would still have at least 60% of the original head, but it would be all in one solid piece, and it would swing better for me.

A stronger man might want to weld a strip over the back edge for reinforcement, and have a heavier axe. I don't know how well the reinforcement would work, but even if it failed, the worst case scenario is that the top of the head breaks off and he has the smaller axe I wanted in the first place.

gooddragon1
2013-10-22, 02:27 PM
A stronger man might want to weld a strip over the back edge for reinforcement, and have a heavier axe. I don't know how well the reinforcement would work, but even if it failed, the worst case scenario is that the top of the head breaks off and he has the smaller axe I wanted in the first place.

That's what I originally thought but I'm still not sure. Thanks anyway guys for letting me axe this question earnestly.