Finally ultralong (several centimeter) carbon nanotube fibers have been made into stronger bundles. The tensile strength of CNTBs (Carbon nanotube bundles) is at least 9–45 times that of other materials. If a more rigorous engineering definition is used, the tensile strength of macroscale CNTBs is still 5–24 times that of any other types of engineering fiber, indicating the extraordinary advantages of ultralong Carbon nanotubes in fabricating superstrong fibers.
The work was done at Tsinghua University and other facilities in Beijing. Researchers were Yunxiang Bai, Rufan Zhang, Xuan Ye, Zhenxing Zhu, Huanhuan Xie, Boyuan Shen, Dali Cai, Bofei Liu, Chenxi Zhang, Zhao Jia, Shenli Zhang, Xide Li & Fei Wei.
A synchronous tightening and relaxing (STR) strategy further improves the alignment of the carbon nanotubes to increase the strength.
Superstrong fibers are in great demand in many high-end fields such as sports equipment, ballistic armour, aeronautics, astronautics and even space elevators. In 2005, the US National Aeronautics and Space Administration (NASA) launched a ‘Strong Tether Challenge’, aiming to find a tether with a specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately, there is still no winner for this challenge. The specific strength of existing fibres such as steel wire ropes (about 0.05–0.33 GPa cm3 per gram), carbon fibres (about 0.5–3.5GPa cm3 per gram) and polymer fibers (about 0.28–4.14GPa cm3 per gram) is far lower than 7.5GPa cm3 per gram). Carbon nanotubes, with inherent tensile strength higher than 100GPa and Young’s modulus over 1TPa, are considered one of the strongest known materials.
Generally, there are three types of CNT:
agglomerated CNTs
vertically aligned CNT (VACNT) arrays
ultralong horizontally aligned CNT (HACNT) arrays (‘ultralong CNTs’ for short).
Almost all the reported CNT fibers are fabricated using agglomerated CNTs or VACNT arrays with lengths less than a few hundred micrometres and with plenty of structural defects and impurities, giving those CNT fibers a tensile strength ranging from about 0.5 to 8.8GPa which is much lower than that of single CNTs.
Ultralong CNTs should have great advantages in fabricating fibers because of their macroscale lengths (ranging from centimeters to decimeters), neat surface, perfect structures and super-parallel alignments. But because the production of ultralong CNTs is extremely low, there have been no reports of fibers fabricated using ultralong CNTs, so the question of whether ultralong CNTBs possess equivalent strength to single CNTs has remained open.
Fabrication of ultralong Carbon Nanotubes into superstrong bundles
Researchers have fabricated CNTBs that are several centimeters long, using ultralong CNTs with defined number and parallel alignment, to quantitatively investigate the relationship between the tensile strength of ultralong-CNT-based fibers and their components. Generally, the ultralong CNTs are synthesized through a gas-flow directed chemical vapor deposition (CVD) method with parallel orientations and large intertube distance on flat substrates. The resulting CNTs usually have one to three walls with perfect structures.
Nature Nanotechnology – Carbon nanotubes (CNTs) are one of the strongest known materials. When assembled into fibers, however, their strength becomes impaired by defects, impurities, random orientations and discontinuous lengths. Fabricating CNT fibers with strength reaching that of a single CNT has been an enduring challenge. Here, researchers demonstrate the fabrication of CNT bundles (CNTBs) that are centimeters long with tensile strength over 80 GPa using ultralong defect-free CNTs. The tensile strength of CNTBs is controlled by the Daniels effect owing to the non-uniformity of the initial strains in the components. We propose a synchronous tightening and relaxing strategy to release these non-uniform initial strains. The fabricated CNTBs, consisting of a large number of components with parallel alignment, defect-free structures, continuous lengths and uniform initial strains, exhibit a tensile strength of 80 GPa (corresponding to an engineering tensile strength of 43 GPa), which is far higher than that of any other strong fiber.
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
Known for identifying cutting edge technologies, he is currently a Co-Founder of a startup and fundraiser for high potential early-stage companies. He is the Head of Research for Allocations for deep technology investments and an Angel Investor at Space Angels.
A frequent speaker at corporations, he has been a TEDx speaker, a Singularity University speaker and guest at numerous interviews for radio and podcasts. He is open to public speaking and advising engagements.
Hand knitted by a Deacon, I assume.
Hand knitted by a Deacon I assume.
I don’t remember if it was covered in this article or elsewhere, but apparently one of the ways to deal with slippage was to bombard the CNTs with an electron beam. This causes them to cross-link, and improves the macroscopic strength significantly.
You flipped your numbers at the end. It was 90 *MJ* and 3 GJ. So only 2 MJ/kg for the nanotubes. This is about where Li metal batteries are at according to wikipedia /wiki/Energy_density . Not quite wind-up cars, but you could make pretty good flywheels out of this. Use something heavy to store more energy, and wrap it in these to keep it from shattering.
I don’t remember if it was covered in this article or elsewhere but apparently one of the ways to deal with slippage was to bombard the CNTs with an electron beam. This causes them to cross-link and improves the macroscopic strength significantly.
You flipped your numbers at the end. It was 90 *MJ* and 3 GJ. So only 2 MJ/kg for the nanotubes. This is about where Li metal batteries are at according to wikipedia /wiki/Energy_density . Not quite wind-up cars but you could make pretty good flywheels out of this. Use something heavy to store more energy and wrap it in these to keep it from shattering.
Doh! You are right, I did stuff up right at the end. 2 MJ/kg, not 60.
Doh! You are right I did stuff up right at the end.2 MJ/kg not 60.
i wonder if fabricating such materials in vacuum and zero G would be simpler than on Earth. It would be interesting to see whether a cable factory could be placed in orbit whereupon it builds a skyhook and lowers it.
i wonder if fabricating such materials in vacuum and zero G would be simpler than on Earth. It would be interesting to see whether a cable factory could be placed in orbit whereupon it builds a skyhook and lowers it.
There’s also the challenge of designing a workable ascent module or “climber” (the part that does the actual elevating on a space elevator). It occurred to me: Why “climb” at all? Just build a two-way pulley system. A continuous loop of CNT-cable(s) runs through a spinning wheel (or bank of such wheels, or sheaves) at the orbiting counterweight and at the ground-side terminal. A “climbing module” at ground level would only need to grab onto the ascending side of the cable, after a brief upward boost.
There’s also the challenge of designing a workable ascent module or climber”” (the part that does the actual elevating on a space elevator). It occurred to me: Why “”””climb”””” at all?Just build a two-way pulley system. A continuous loop of CNT-cable(s) runs through a spinning wheel (or bank of such wheels”””” or sheaves) at the orbiting counterweight and at the ground-side terminal. A “”””climbing module”””” at ground level would only need to grab onto the ascending side of the cable”””” after a brief upward boost.”””
I think that’s a natural weak spot even if you trim your toenails often. If you pull your socks tightly and over strain them that is where it will fail first.
I think that’s a natural weak spot even if you trim your toenails often. If you pull your socks tightly and over strain them that is where it will fail first.
Mine mostly get ruined before they’re lost. Usually they get a hole in them at one of the toes. Sometimes on first use…
Mine mostly get ruined before they’re lost. Usually they get a hole in them at one of the toes. Sometimes on first use…
Hopefully space will remain a peaceful place and all countries and organizations and people will take advantage of it and permuting free trade.
Hopefully space will remain a peaceful place and all countries and organizations and people will take advantage of it and permuting free trade.
Who told you that? The rocket equation says that if you cut a rockets weight in half you would require ten times less fuel. SPACEX’ BFR is designed with lightweight high strength carbon fiber composites for that reason.
Who told you that? The rocket equation says that if you cut a rockets weight in half you would require ten times less fuel.SPACEX’ BFR is designed with lightweight high strength carbon fiber composites for that reason.
Kevlar has an amazingly high energy to rupture which is a different measure of strength than tensile strength, which is its stretchiness and ability to spring back undamaged. The carbon nanotube fibers of this article might not surpass kevlar in its ability to absorb shock from protect from bullets and explosions. A combination of kevlar and the new fibers might be ideal bulletproofing material though.
Kevlar has an amazingly high energy to rupture which is a different measure of strength than tensile strength which is its stretchiness and ability to spring back undamaged. The carbon nanotube fibers of this article might not surpass kevlar in its ability to absorb shock from protect from bullets and explosions. A combination of kevlar and the new fibers might be ideal bulletproofing material though.
Wake me up when, 70 years or so after Yuri Gagarin, Musk will be able to put one man in space.. And do not forget that Chinese are able to copy things very very fast.
Wake me up when 70 years or so after Yuri Gagarin Musk will be able to put one man in space.. And do not forget that Chinese are able to copy things very very fast.
Point is that TSMC makes chips and Foxconn assembles Iphones as it all started when China` s GDP was 1/10 or so of the US . Now they are almost equal and soon will pass the US. So China will have little incentive to pass their technology to an poorer country. Just think about it
Point is that TSMC makes chips and Foxconn assembles Iphones as it all started when China` s GDP was 1/10 or so of the US . Now they are almost equal and soon will pass the US. So China will have little incentive to pass their technology to an poorer country. Just think about it
And by the time China has a space elevator, at least there will be lots of American space stations to visit from the 250 BFR flights that have taken place by that time.
And by the time China has a space elevator at least there will be lots of American space stations to visit from the 250 BFR flights that have taken place by that time.
S/c material durability/strength is not a major limiting factor on rocket size.
S/c material durability/strength is not a major limiting factor on rocket size.
Dude, relax. We’re all on this planet together. They’re sharing their science (at least at the conceptual level), so other scientists will work on this as well. And guess what, some of those scientists will be from other countries! Even if it is the Chinese who solely produce this (and the first person to come up with something is rarely the person who makes money selling it), they’ll sell it to the highest bidder, just like their production of rare earth metals, or under contract like iPhones.
Dude relax. We’re all on this planet together. They’re sharing their science (at least at the conceptual level) so other scientists will work on this as well. And guess what some of those scientists will be from other countries! Even if it is the Chinese who solely produce this (and the first person to come up with something is rarely the person who makes money selling it) they’ll sell it to the highest bidder just like their production of rare earth metals or under contract like iPhones.
Great explanation, and you’re right I didn’t know that. Thanks!
Great explanation and you’re right I didn’t know that. Thanks!
Not you. The Chinese The Chinese are making bundles centimeters long, this seems to be a Chinese University If China will make bundles longer and longer the US will be cut off So it will be THEY being able to make fibers kilometers near long, not YOU
Not you. The Chinese The Chinese are making bundles centimeters long this seems to be a Chinese University If China will make bundles longer and longer the US will be cut offSo it will be THEY being able to make fibers kilometers near long not YOU
No you do not. Apparently the resrearch was made in China so it will be China who will have fibers for Space elevators, not the US Your name does not look Chinese, due
No you do not. Apparently the resrearch was made in China so it will be China who will have fibers for Space elevators not the US Your name does not look Chinese due
So finally I’ll have strong socks?
So finally I’ll have strong socks?
Because Michael K knows what he’s talking about, but Dennis (and other readers) may not, I’ll expand out the definition of Engineering and Ultimate Tensile Strength. Engineering Tensile Strength: You have a cable with a cross section of 1 square meter (large, but not unrealistic, and convenient for calculations). You start to load it up. Eventually you reach a load of 43 billion newtons. About 4.5 billion kg, 4.5 million tonnes. A lot. At this point it breaks. OK, the strength is 43 billion newtons, 4.3 GN, divided by 1 square meter = 43GPa. You can scale this up and down with the cross sectional area. If you have 1 square millimeter, that’s one millionth the area, so it will take one millionth the load (43 thousand newtons = 4.5 tonnes = light truck hanging from a single fishing line) OK, but when you start to load the cable, it starts to stretch. When it stretches it gets longer, and thinner. (OK, there are super weird materials that don’t get thinner, some even get fatter, but we can ignore them for any normal discussion.) So when it breaks it isn’t 1 square meter. It will be less. In this case apparently it gets to only a bit over half the original cross section. So if you calculate the real stress you are dividing 43 GN by 0.54 square meters equals 80 GPa. So which is important? It depends what you want to do. If you have a load and you want to lift it up, you need to know what sized cable to use, so you use 43 GPa. But if you are designing a space elevator, then the cable will be under load the entire time, so you need to design it using the shape it will be in under load. Which uses the 80 GPa figure.
Because Michael K knows what he’s talking about but Dennis (and other readers) may not I’ll expand out the definition of Engineering and Ultimate Tensile Strength.Engineering Tensile Strength: You have a cable with a cross section of 1 square meter (large but not unrealistic and convenient for calculations). You start to load it up. Eventually you reach a load of 43 billion newtons. About 4.5 billion kg 4.5 million tonnes. A lot.At this point it breaks. OK the strength is 43 billion newtons 4.3 GN divided by 1 square meter = 43GPa. You can scale this up and down with the cross sectional area. If you have 1 square millimeter that’s one millionth the area so it will take one millionth the load (43 thousand newtons = 4.5 tonnes = light truck hanging from a single fishing line)OK but when you start to load the cable it starts to stretch. When it stretches it gets longer and thinner. (OK there are super weird materials that don’t get thinner some even get fatter but we can ignore them for any normal discussion.) So when it breaks it isn’t 1 square meter. It will be less. In this case apparently it gets to only a bit over half the original cross section. So if you calculate the real stress you are dividing 43 GN by 0.54 square meters equals 80 GPa.So which is important? It depends what you want to do. If you have a load and you want to lift it up you need to know what sized cable to use so you use 43 GPa. But if you are designing a space elevator then the cable will be under load the entire time so you need to design it using the shape it will be in under load. Which uses the 80 GPa figure.
You’d use cheap stuff like metal, glass, or polypropylene fibers to reinforce concrete, not carbon fibers. I can imagine that plastics or composites could be heavily reinforced with these CNTBs. What about making next-generation spacecraft out of CNTB-reinforced composites? Then you could make some really, really, really big rockets.
You’d use cheap stuff like metal glass or polypropylene fibers to reinforce concrete not carbon fibers. I can imagine that plastics or composites could be heavily reinforced with these CNTBs.What about making next-generation spacecraft out of CNTB-reinforced composites? Then you could make some really really really big rockets.
You’re confusing several different types of numbers: The 43 GPa is the “engineering tensile strength”, which is an inaccurate estimate of the strength, not accounting for deformation and not accounting for density. It’s specified because that’s the number that’s easiest to measure directly. The “true tensile strength” takes that, and factors in the deformation. It’s stated here as 80 GPa. Finally, the desired figure of “7.5GPa cm3 per gram” (or 7.5 [GPa*cm^3/g]) is the *specific* strength, which also takes density into account. Notice the different units. To get the specific strength, divide the true strength by the density. Taking a typical CNT density of ~1.5 g/cc, 80 GPa, translates to 53 [GPa*cm^3/g]. So perhaps indeed strong enough. But these are still small bundles, and not a tether. The production still needs to be scaled up by several orders of magnitude, the price needs to come down, and tethers still need to be spun out of this.
You’re confusing several different types of numbers:The 43 GPa is the engineering tensile strength””” which is an inaccurate estimate of the strength”” not accounting for deformation and not accounting for density. It’s specified because that’s the number that’s easiest to measure directly.The “”””true tensile strength”””” takes that”” and factors in the deformation. It’s stated here as 80 GPa.Finally”” the desired figure of “”””7.5GPa cm3 per gram”””” (or 7.5 [GPa*cm^3/g]) is the *specific* strength”” which also takes density into account. Notice the different units. To get the specific strength divide the true strength by the density.Taking a typical CNT density of ~1.5 g/cc 80 GPa translates to 53 [GPa*cm^3/g]. So perhaps indeed strong enough. But these are still small bundles and not a tether. The production still needs to be scaled up by several orders of magnitude the price needs to come down”” and tethers still need to be spun out of this.”””
There’s also the challenge of designing a workable ascent module or “climber” (the part that does the actual elevating on a space elevator). It occurred to me: Why “climb” at all? Just build a two-way pulley system. A continuous loop of CNT-cable(s) runs through a spinning wheel (or bank of such wheels, or sheaves) at the orbiting counterweight and at the ground-side terminal. A “climbing module” at ground level would only need to grab onto the ascending side of the cable, after a brief upward boost.
There’s also the challenge of designing a workable ascent module or climber”” (the part that does the actual elevating on a space elevator). It occurred to me: Why “”””climb”””” at all?Just build a two-way pulley system. A continuous loop of CNT-cable(s) runs through a spinning wheel (or bank of such wheels”””” or sheaves) at the orbiting counterweight and at the ground-side terminal. A “”””climbing module”””” at ground level would only need to grab onto the ascending side of the cable”””” after a brief upward boost.”””
i wonder if fabricating such materials in vacuum and zero G would be simpler than on Earth. It would be interesting to see whether a cable factory could be placed in orbit whereupon it builds a skyhook and lowers it.
i wonder if fabricating such materials in vacuum and zero G would be simpler than on Earth. It would be interesting to see whether a cable factory could be placed in orbit whereupon it builds a skyhook and lowers it.
There’s also the challenge of designing a workable ascent module or “climber” (the part that does the actual elevating on a space elevator). It occurred to me: Why “climb” at all?
Just build a two-way pulley system. A continuous loop of CNT-cable(s) runs through a spinning wheel (or bank of such wheels, or sheaves) at the orbiting counterweight and at the ground-side terminal. A “climbing module” at ground level would only need to grab onto the ascending side of the cable, after a brief upward boost.
i wonder if fabricating such materials in vacuum and zero G would be simpler than on Earth. It would be interesting to see whether a cable factory could be placed in orbit whereupon it builds a skyhook and lowers it.
Doh! You are right, I did stuff up right at the end. 2 MJ/kg, not 60.
Doh! You are right I did stuff up right at the end.2 MJ/kg not 60.
Doh! You are right, I did stuff up right at the end.
2 MJ/kg, not 60.
I don’t remember if it was covered in this article or elsewhere, but apparently one of the ways to deal with slippage was to bombard the CNTs with an electron beam. This causes them to cross-link, and improves the macroscopic strength significantly.
I don’t remember if it was covered in this article or elsewhere but apparently one of the ways to deal with slippage was to bombard the CNTs with an electron beam. This causes them to cross-link and improves the macroscopic strength significantly.
You flipped your numbers at the end. It was 90 *MJ* and 3 GJ. So only 2 MJ/kg for the nanotubes. This is about where Li metal batteries are at according to wikipedia /wiki/Energy_density . Not quite wind-up cars, but you could make pretty good flywheels out of this. Use something heavy to store more energy, and wrap it in these to keep it from shattering.
You flipped your numbers at the end. It was 90 *MJ* and 3 GJ. So only 2 MJ/kg for the nanotubes. This is about where Li metal batteries are at according to wikipedia /wiki/Energy_density . Not quite wind-up cars but you could make pretty good flywheels out of this. Use something heavy to store more energy and wrap it in these to keep it from shattering.
Hand knitted by a Deacon, I assume.
Hand knitted by a Deacon I assume.
I don’t remember if it was covered in this article or elsewhere, but apparently one of the ways to deal with slippage was to bombard the CNTs with an electron beam. This causes them to cross-link, and improves the macroscopic strength significantly.
You flipped your numbers at the end. It was 90 *MJ* and 3 GJ. So only 2 MJ/kg for the nanotubes. This is about where Li metal batteries are at according to wikipedia /wiki/Energy_density . Not quite wind-up cars, but you could make pretty good flywheels out of this. Use something heavy to store more energy, and wrap it in these to keep it from shattering.
Hand knitted by a Deacon, I assume.
I think that’s a natural weak spot even if you trim your toenails often. If you pull your socks tightly and over strain them that is where it will fail first.
I think that’s a natural weak spot even if you trim your toenails often. If you pull your socks tightly and over strain them that is where it will fail first.
Mine mostly get ruined before they’re lost. Usually they get a hole in them at one of the toes. Sometimes on first use…
Mine mostly get ruined before they’re lost. Usually they get a hole in them at one of the toes. Sometimes on first use…
I think that’s a natural weak spot even if you trim your toenails often. If you pull your socks tightly and over strain them that is where it will fail first.
Hopefully space will remain a peaceful place and all countries and organizations and people will take advantage of it and permuting free trade.
Hopefully space will remain a peaceful place and all countries and organizations and people will take advantage of it and permuting free trade.
Who told you that? The rocket equation says that if you cut a rockets weight in half you would require ten times less fuel. SPACEX’ BFR is designed with lightweight high strength carbon fiber composites for that reason.
Who told you that? The rocket equation says that if you cut a rockets weight in half you would require ten times less fuel.SPACEX’ BFR is designed with lightweight high strength carbon fiber composites for that reason.
Kevlar has an amazingly high energy to rupture which is a different measure of strength than tensile strength, which is its stretchiness and ability to spring back undamaged. The carbon nanotube fibers of this article might not surpass kevlar in its ability to absorb shock from protect from bullets and explosions. A combination of kevlar and the new fibers might be ideal bulletproofing material though.
Kevlar has an amazingly high energy to rupture which is a different measure of strength than tensile strength which is its stretchiness and ability to spring back undamaged. The carbon nanotube fibers of this article might not surpass kevlar in its ability to absorb shock from protect from bullets and explosions. A combination of kevlar and the new fibers might be ideal bulletproofing material though.
Wake me up when, 70 years or so after Yuri Gagarin, Musk will be able to put one man in space.. And do not forget that Chinese are able to copy things very very fast.
Wake me up when 70 years or so after Yuri Gagarin Musk will be able to put one man in space.. And do not forget that Chinese are able to copy things very very fast.
Point is that TSMC makes chips and Foxconn assembles Iphones as it all started when China` s GDP was 1/10 or so of the US . Now they are almost equal and soon will pass the US. So China will have little incentive to pass their technology to an poorer country. Just think about it
Point is that TSMC makes chips and Foxconn assembles Iphones as it all started when China` s GDP was 1/10 or so of the US . Now they are almost equal and soon will pass the US. So China will have little incentive to pass their technology to an poorer country. Just think about it
And by the time China has a space elevator, at least there will be lots of American space stations to visit from the 250 BFR flights that have taken place by that time.
And by the time China has a space elevator at least there will be lots of American space stations to visit from the 250 BFR flights that have taken place by that time.
S/c material durability/strength is not a major limiting factor on rocket size.
S/c material durability/strength is not a major limiting factor on rocket size.
Mine mostly get ruined before they’re lost. Usually they get a hole in them at one of the toes. Sometimes on first use…
Dude, relax. We’re all on this planet together. They’re sharing their science (at least at the conceptual level), so other scientists will work on this as well. And guess what, some of those scientists will be from other countries! Even if it is the Chinese who solely produce this (and the first person to come up with something is rarely the person who makes money selling it), they’ll sell it to the highest bidder, just like their production of rare earth metals, or under contract like iPhones.
Dude relax. We’re all on this planet together. They’re sharing their science (at least at the conceptual level) so other scientists will work on this as well. And guess what some of those scientists will be from other countries! Even if it is the Chinese who solely produce this (and the first person to come up with something is rarely the person who makes money selling it) they’ll sell it to the highest bidder just like their production of rare earth metals or under contract like iPhones.
Hopefully space will remain a peaceful place and all countries and organizations and people will take advantage of it and permuting free trade.
Who told you that? The rocket equation says that if you cut a rockets weight in half you would require ten times less fuel.
SPACEX’ BFR is designed with lightweight high strength carbon fiber composites for that reason.
Kevlar has an amazingly high energy to rupture which is a different measure of strength than tensile strength, which is its stretchiness and ability to spring back undamaged. The carbon nanotube fibers of this article might not surpass kevlar in its ability to absorb shock from protect from bullets and explosions. A combination of kevlar and the new fibers might be ideal bulletproofing material though.
Great explanation, and you’re right I didn’t know that. Thanks!
Great explanation and you’re right I didn’t know that. Thanks!
Wake me up when, 70 years or so after Yuri Gagarin, Musk will be able to put one man in space..
And do not forget that Chinese are able to copy things very very fast.
Point is that TSMC makes chips and Foxconn assembles Iphones as it all started when China` s GDP was 1/10 or so of the US . Now they are almost equal and soon will pass the US. So China will have little incentive to pass their technology to an poorer country.
Just think about it
Not you. The Chinese The Chinese are making bundles centimeters long, this seems to be a Chinese University If China will make bundles longer and longer the US will be cut off So it will be THEY being able to make fibers kilometers near long, not YOU
Not you. The Chinese The Chinese are making bundles centimeters long this seems to be a Chinese University If China will make bundles longer and longer the US will be cut offSo it will be THEY being able to make fibers kilometers near long not YOU
No you do not. Apparently the resrearch was made in China so it will be China who will have fibers for Space elevators, not the US Your name does not look Chinese, due
No you do not. Apparently the resrearch was made in China so it will be China who will have fibers for Space elevators not the US Your name does not look Chinese due
So finally I’ll have strong socks?
So finally I’ll have strong socks?
And by the time China has a space elevator, at least there will be lots of American space stations to visit from the 250 BFR flights that have taken place by that time.
S/c material durability/strength is not a major limiting factor on rocket size.
Dude, relax. We’re all on this planet together. They’re sharing their science (at least at the conceptual level), so other scientists will work on this as well. And guess what, some of those scientists will be from other countries! Even if it is the Chinese who solely produce this (and the first person to come up with something is rarely the person who makes money selling it), they’ll sell it to the highest bidder, just like their production of rare earth metals, or under contract like iPhones.
Because Michael K knows what he’s talking about, but Dennis (and other readers) may not, I’ll expand out the definition of Engineering and Ultimate Tensile Strength. Engineering Tensile Strength: You have a cable with a cross section of 1 square meter (large, but not unrealistic, and convenient for calculations). You start to load it up. Eventually you reach a load of 43 billion newtons. About 4.5 billion kg, 4.5 million tonnes. A lot. At this point it breaks. OK, the strength is 43 billion newtons, 4.3 GN, divided by 1 square meter = 43GPa. You can scale this up and down with the cross sectional area. If you have 1 square millimeter, that’s one millionth the area, so it will take one millionth the load (43 thousand newtons = 4.5 tonnes = light truck hanging from a single fishing line) OK, but when you start to load the cable, it starts to stretch. When it stretches it gets longer, and thinner. (OK, there are super weird materials that don’t get thinner, some even get fatter, but we can ignore them for any normal discussion.) So when it breaks it isn’t 1 square meter. It will be less. In this case apparently it gets to only a bit over half the original cross section. So if you calculate the real stress you are dividing 43 GN by 0.54 square meters equals 80 GPa. So which is important? It depends what you want to do. If you have a load and you want to lift it up, you need to know what sized cable to use, so you use 43 GPa. But if you are designing a space elevator, then the cable will be under load the entire time, so you need to design it using the shape it will be in under load. Which uses the 80 GPa figure.
Because Michael K knows what he’s talking about but Dennis (and other readers) may not I’ll expand out the definition of Engineering and Ultimate Tensile Strength.Engineering Tensile Strength: You have a cable with a cross section of 1 square meter (large but not unrealistic and convenient for calculations). You start to load it up. Eventually you reach a load of 43 billion newtons. About 4.5 billion kg 4.5 million tonnes. A lot.At this point it breaks. OK the strength is 43 billion newtons 4.3 GN divided by 1 square meter = 43GPa. You can scale this up and down with the cross sectional area. If you have 1 square millimeter that’s one millionth the area so it will take one millionth the load (43 thousand newtons = 4.5 tonnes = light truck hanging from a single fishing line)OK but when you start to load the cable it starts to stretch. When it stretches it gets longer and thinner. (OK there are super weird materials that don’t get thinner some even get fatter but we can ignore them for any normal discussion.) So when it breaks it isn’t 1 square meter. It will be less. In this case apparently it gets to only a bit over half the original cross section. So if you calculate the real stress you are dividing 43 GN by 0.54 square meters equals 80 GPa.So which is important? It depends what you want to do. If you have a load and you want to lift it up you need to know what sized cable to use so you use 43 GPa. But if you are designing a space elevator then the cable will be under load the entire time so you need to design it using the shape it will be in under load. Which uses the 80 GPa figure.
Great explanation, and you’re right I didn’t know that. Thanks!
You’d use cheap stuff like metal, glass, or polypropylene fibers to reinforce concrete, not carbon fibers. I can imagine that plastics or composites could be heavily reinforced with these CNTBs. What about making next-generation spacecraft out of CNTB-reinforced composites? Then you could make some really, really, really big rockets.
You’d use cheap stuff like metal glass or polypropylene fibers to reinforce concrete not carbon fibers. I can imagine that plastics or composites could be heavily reinforced with these CNTBs.What about making next-generation spacecraft out of CNTB-reinforced composites? Then you could make some really really really big rockets.
Not you. The Chinese
The Chinese are making bundles centimeters long, this seems to be a Chinese University
If China will make bundles longer and longer the US will be cut off
So it will be THEY being able to make fibers kilometers near long, not YOU
No you do not.
Apparently the resrearch was made in China so it will be China who will have fibers for Space elevators, not the US
Your name does not look Chinese, due
You’re confusing several different types of numbers: The 43 GPa is the “engineering tensile strength”, which is an inaccurate estimate of the strength, not accounting for deformation and not accounting for density. It’s specified because that’s the number that’s easiest to measure directly. The “true tensile strength” takes that, and factors in the deformation. It’s stated here as 80 GPa. Finally, the desired figure of “7.5GPa cm3 per gram” (or 7.5 [GPa*cm^3/g]) is the *specific* strength, which also takes density into account. Notice the different units. To get the specific strength, divide the true strength by the density. Taking a typical CNT density of ~1.5 g/cc, 80 GPa, translates to 53 [GPa*cm^3/g]. So perhaps indeed strong enough. But these are still small bundles, and not a tether. The production still needs to be scaled up by several orders of magnitude, the price needs to come down, and tethers still need to be spun out of this.
You’re confusing several different types of numbers:The 43 GPa is the engineering tensile strength””” which is an inaccurate estimate of the strength”” not accounting for deformation and not accounting for density. It’s specified because that’s the number that’s easiest to measure directly.The “”””true tensile strength”””” takes that”” and factors in the deformation. It’s stated here as 80 GPa.Finally”” the desired figure of “”””7.5GPa cm3 per gram”””” (or 7.5 [GPa*cm^3/g]) is the *specific* strength”” which also takes density into account. Notice the different units. To get the specific strength divide the true strength by the density.Taking a typical CNT density of ~1.5 g/cc 80 GPa translates to 53 [GPa*cm^3/g]. So perhaps indeed strong enough. But these are still small bundles and not a tether. The production still needs to be scaled up by several orders of magnitude the price needs to come down”” and tethers still need to be spun out of this.”””
So finally I’ll have strong socks?
Get the price down and the tensile strength up. It would be great for bullet proof vest, flywheel energy storage, and re-enforced concrete.
Get the price down and the tensile strength up. It would be great for bullet proof vest flywheel energy storage and re-enforced concrete.
Get the price down and the tensile strength up. It would be great for bullet proof vest, flywheel energy storage, and re-enforced concrete.
Get the price down and the tensile strength up. It would be great for bullet proof vest flywheel energy storage and re-enforced concrete.
specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately, there is still no winner for this challenge.” But these new fibers are supposed to be 43GPa….is this article saying that we now have fibers sufficient for space elevators?
specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately” there is still no winner for this challenge.””But these new fibers are supposed to be 43GPa….is this article saying that we now have fibers sufficient for space elevators?”””
specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately, there is still no winner for this challenge.” But these new fibers are supposed to be 43GPa….is this article saying that we now have fibers sufficient for space elevators?
specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately” there is still no winner for this challenge.””But these new fibers are supposed to be 43GPa….is this article saying that we now have fibers sufficient for space elevators?”””
Because Michael K knows what he’s talking about, but Dennis (and other readers) may not, I’ll expand out the definition of Engineering and Ultimate Tensile Strength.
Engineering Tensile Strength: You have a cable with a cross section of 1 square meter (large, but not unrealistic, and convenient for calculations). You start to load it up. Eventually you reach a load of 43 billion newtons. About 4.5 billion kg, 4.5 million tonnes. A lot.
At this point it breaks. OK, the strength is 43 billion newtons, 4.3 GN, divided by 1 square meter = 43GPa. You can scale this up and down with the cross sectional area. If you have 1 square millimeter, that’s one millionth the area, so it will take one millionth the load (43 thousand newtons = 4.5 tonnes = light truck hanging from a single fishing line)
OK, but when you start to load the cable, it starts to stretch. When it stretches it gets longer, and thinner. (OK, there are super weird materials that don’t get thinner, some even get fatter, but we can ignore them for any normal discussion.) So when it breaks it isn’t 1 square meter. It will be less. In this case apparently it gets to only a bit over half the original cross section. So if you calculate the real stress you are dividing 43 GN by 0.54 square meters equals 80 GPa.
So which is important? It depends what you want to do. If you have a load and you want to lift it up, you need to know what sized cable to use, so you use 43 GPa. But if you are designing a space elevator, then the cable will be under load the entire time, so you need to design it using the shape it will be in under load. Which uses the 80 GPa figure.
You’d use cheap stuff like metal, glass, or polypropylene fibers to reinforce concrete, not carbon fibers. I can imagine that plastics or composites could be heavily reinforced with these CNTBs.
What about making next-generation spacecraft out of CNTB-reinforced composites? Then you could make some really, really, really big rockets.
You’re confusing several different types of numbers:
The 43 GPa is the “engineering tensile strength”, which is an inaccurate estimate of the strength, not accounting for deformation and not accounting for density. It’s specified because that’s the number that’s easiest to measure directly.
The “true tensile strength” takes that, and factors in the deformation. It’s stated here as 80 GPa.
Finally, the desired figure of “7.5GPa cm3 per gram” (or 7.5 [GPa*cm^3/g]) is the *specific* strength, which also takes density into account. Notice the different units. To get the specific strength, divide the true strength by the density.
Taking a typical CNT density of ~1.5 g/cc, 80 GPa, translates to 53 [GPa*cm^3/g]. So perhaps indeed strong enough. But these are still small bundles, and not a tether. The production still needs to be scaled up by several orders of magnitude, the price needs to come down, and tethers still need to be spun out of this.
Get the price down and the tensile strength up. It would be great for bullet proof vest, flywheel energy storage, and re-enforced concrete.
“specific strength up to 7.5GPa cm3 per gram for the dream of making space elevators. Unfortunately, there is still no winner for this challenge.”
But these new fibers are supposed to be 43GPa….is this article saying that we now have fibers sufficient for space elevators?