Taking the "what the frack" out of materials engineering

San Andreas Fault Which way does the fault line run? Scott Haefner/USGS

Puzzlement over how to predict fractures in real-world materials has finally given way before a new mathematical model that describes exactly how materials crack under pressure.

The simulation can predict crack patterns in materials that include glass, polymers, concrete, ceramics, metals and rocks. It replicates all stages in the fracture process from beginning to end, ranging from the microscopic scale to huge geological faults in the Earth that are responsible for earthquakes.

Such modeling found that materials can break in three different ways: top to bottom, horizontally like a cut, or as a tear, such as when a cable gets pulled and twisted simultaneously. Polymer materials crack like rocks, and glass breaks along the same crack lines as the Earth's geological faults.

Scientists previously struggled with just modeling how 2-D objects such as paper would rip or tear. The new model, detailed in the first March issue of the journal Nature, could help solve "natural problems that have technological implications," according to Antonio Pons, a physicist at the Universitat Politècnica de Catalunya (UPC)-Barcelona Tech in Spain.

That might lead to better understanding of how seismological stress caused by enhanced geothermal power might trigger earthquakes, or knowing just how osteoporosis patients might be vulnerable to breaking their bones. We can also think of some new ceramics and other materials that could use the advance failure analysis.

[via ScienceDaily]

3 Comments

How precise? is there still probability involved? If so, is this a metaphysical probability that reflects indeterminism or do materials fracture in a deterministic way (just wondering if we have indeterminism at any higher level than qm, notwithstanding the free will debate).

I'm much less than a math amateur in asking the following: Are fractals involved in this modeling?

I'm sure the model can only be as accurate as the information gathered. I doubt we have perfect ways to analyze 100% the rock/soil conditions, density, faults, etc. I think even with a perfect model for measuring faults on a small scale, on the large scale i feel it will not be perfect without great deal of information gathering, etc. Although would be interesting to see how much it improves out current predictions. Maybe it could be used to even predict earthquakes sometime, or at least get an estimate like the weather....

of course, i don't know anything about the subject matter.

well... even at our best efforts, our fractals only hold true for D < 10. there seems to be something interfering at a frequency (or shall i say, frequencies) that resonates with materials at certain scales, thus the same pattern found when looking at a kidney biopsy slide and a satellite image of the amazon basin from, say, 2km up.

Those are only the most noticable. The way a certain sized heap of sand weathers similarly to a mountain range present harmony (that is the same fractal can model those two processes which obviously occur at vastly different scales), yet that same pile of sand mimics that of some fluids when under a different set of conditions.

So perhaps its not some external resonance causing this pattern to propagate, but the properties of the material the laws of the universe is acting on.

either way, we cannot absolutely model material fractures since, as Zengrath said, we cannot capture enough information about the system. in order to get enough information, we have to look at it very closely, but doing so disrupts the particles we are observing, hence changing the information within. Classic paradox, Heisenberg uncertainty. So when you have the information, its useless since the material will crack differently.

And now the spooky question: "When you look at that atom, does its information (electron orbits) change for all those types of atoms in existence? Because you dont know what it changed to when you observed it, the next time you look at it, it seems random.

it inevitably comes down to electron clouds with fluctuating energies deciding exactly where two molecules will split when the material cracks... and thus because we the observer are made of those materials ourselves, we can never quantify these things absolutely, unless we could step into the next dimension, in which case the existence of our entire universe will be some line in the sand, somewhere on an island, where the fractal continues beyond the scope of our imagination.

: )



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