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3D-Printed Material Can Carry 160,000 Times Its Own Weight
rtoz writes: Researchers have found a new material design based on the use of microlattices with nanoscale features, combining great stiffness and strength with ultralow density. The actual production of such materials is made possible by a high-precision 3-D printing process called projection microstereolithography. Normally, stiffness and strength declines with the density of any material; that's why when bone density decreases, fractures become more likely. But using the right mathematically determined structures to distribute and direct the loads, the lighter structure can maintain its strength. This newly invented material is among the lightest in the world. It can easily withstand a load of more than 160,000 times its own weight.
No, not really.
It's got a great strength to weight ratio, but it might be better to say they reduced the effective weight while retaining most of the strength of the material.
The stuff needed for the cable of a tethered satellite needs a lot more than just a great weight to strength ratio, it needs a certain level of strength and resilience.
Look at it this way, if you had a steel component that weighed 1,000lbs and could hold up 20,000lbs and you replaced it with this type of similar to aerogel lattice type steel component, you are looking at a tiny weight (probably) less than 3 lbs, and it could still hold up around 20,000lbs. Of course, if the project needed a component that size that was able to hold up 50,000lbs, neither one would be feasible.
Some people might suggest that you could just make it bigger, but that's often not a feasible idea, even if it is lighter than the usual materials. For one example is why skyscrapers are not made of brick. It doesn't matter how wide your walls of brick would be, after a certain point, the weight of the bricks would crush the lower ones, and then the whole building collapses. The steel reinforced concrete we use can sustain much larger loads, and so is used for tall and heavy projects instead of bricks. Of course tethered satellite has to withstand much greater stresses, whether it's crushing down, pulling up, or swaying to the side. That's why super light but otherwise more conventional materials won't work.
No, read it as.... ...because of that follows next:
"Normally, stiffness and strength declines with the [decline in] density of any [single] material;"
"that's why when bone density decreases, fractures become more likely."
You: Read it again: declines with density. DECLINES. Mercury is very dense, hence its stiffness has DECLINED to the point where it is very low.
Subby: "that's why when bone density decreases, fractures become more likely"
Someone's incorrect here.
Fruth Innovative Technologien has developed an algorithm to fill large volumes with such a scaffolding quickly. This speeds up building time and saves on the precious sinter powder, and yes, the scaffolding is very strong for its weight. They do this for more than a decade now. And now a MIT professor comes up with the same idea, and it is presented as a breakthrough. MIT marketing at work.
You know it's time for the next revolution when your rulers' names end with roman numerals.
Would this material make one possible?
No.
A space elevator cable needs to have insanely high Tensile strength combined with the ability to not deform/stretch.
It's described as similar to an arogel with the strength of rubber. With that description it sounds like its
Tesile strength is terrible while its compressive strength is what's great... which would make it a bad match for a space elevator cable. Though, what's interesting here is the process... they could use it to design other materials with different geometries and different properties I'd think.
Space elevator cable first needs very high tensile strength just to hold it own weight (thats 22000 mile PLUS the counterweight portion extending outwards to counter the downward pull (some designs make that another duplicate cable going out that much further 22000 more miles).
Anyway, for the thing to work as a elevator the mechanism that goes up and down has to grip the cable and generate sufficient friction to move against gravity and then upwards (and to brake on the way down). That 'gripping' puts shear stress on the cable material as it squeezes the cable (requiring an armored surfacing which NOW has to exist on that long length ....more weight).
Strengthen that high tensile material itself ? Like the epoxy matrix around graphite fiber -- how much weight is that going to be that will greatly increase the weight of the entire cable (it adds little to the tensile up down strength)?? Thats now compression strength built up across the cable diameter, (actually across it to the opposite side) and intermeshed with the axial oriented cable tension element so it wont slip.
LOTS more weight to the whole thing (matrix might have to be many times the density/total weight of the linear element) which the tensile material will NOW have to hold all the weight of.
Lets not forget things like thermal stress on the materials, countermeasures against corrosion of all kinds, and added surge margins to compensate for irregular stress conditions
Another fun thing is because the weight hanging/pulling upwards varies at different points along the cable the strength required can vary, thus its thickness may also (to cut down its required weight somewhat)
Your own example disproves your argument: if the bricks in your skyscraper weighed much less (but had the same compression strength), then you could stack many more of them on top before the bottom brick would be crushed, allowing you to build a taller skyscraper.
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