Wouldn't the easiest way to fracture something be to use

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>>7678063
>Alternatively as a way to improve a pickaxe/pneumatic-drill if the vibration is more linear than radial would be to have two impacts, one occurring a tiny fraction of a second later.
you're a fucking genius, anon

>>7678101
This sounds like sarcasm, but if it is, it's very subtle.

Bump I guess

>>7678110
I mean, a jackhammer hits fast & never quite the same place twice.
What you're saying is the best form might be an endlessly sharp slightly pronged jackhammer. Otherwise, they're the best tool to date for causing fractures.

>>7678063
Dynamite works pretty well to shatter stuff and it employs a radial shockwave.

>>7678277
A jackhammer isn't fast enough to perfectly employ what I'm talking about though, but I think you might be right that it does employ it to some extent.
There are a couple possible ways it could be improved though.

A: The second hit should occur 0.5/f (where f is the frequency of the shockwave) seconds after the first if the shockwaves are narrow and the intent is to make the rock vibrate in opposition to itself.
This effect would work best with a two-headed jackhammer or one with a head that aims itself at two different spots, because it would mean that one gets both improvements A and B.

B: The second hit should occur 1/f seconds after the first in exactly the same place, so that the vibrations amplify to become extremely strong.

>>7678438
But could two sticks spaced a short distance apart work better than two sticks in exactly the same place?

yes you are correct

I've been think of improved ways of mining too.

I imagine you could use the principle of teslas oscillator, calculate and input the surface tension of your material.

and vibrate it to exactly right, to break it with the shockwaves interfering inside the material.

explosion welding might have something to do with it.

>>7678277
An endlessly sharp tool could just be used as a wedge, likely with a much better efficiency.

>>7679254
My guess is that any antinode would only be as strong as that formed by placing the dynamite sticks together.

Apart from that I'm pretty sure we're just talking resonance. A quick idea that pops into my head is finding a way to bond the striking tool to the surface after impact or removing it from the surface before it can rebound, increasing the strength of the pressure oscillations by capturing the energy that would be elastically transferred back into the tool and simply bouncing off. Although the added mass would likely tear off a tiny chunk at the impact site if it were to bond.

>>7679462
I know the antinode strength wouldn't change, but a single radial blast has concentric circles of antinodes, whereas two separate blasts create a checkerboard of opposing antinodes.
The latter sounds like it would be much more stressful to the rock.

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>>7679554
The pressure gradient wouldn't be any more severe with two wave sources, in most places it would actually be less severe. You're spreading the energy over a larger area.

>>7679615
Consider, though, that if a shockwave is waves of compression, with a single ripple the only places where there's differences in compression is between peaks and trough of that wave.
By having nodal and antinodal lines, the movement of the rock is much more complicated, which sounds like it would be more destructive.
That is, I'd expect the rock to be more likely to break between a nodal and antinodal line.