jb5
Super Anarchist
https://www.bbc.com/news/world-us-canada-49500642
Front page headline on the BBC site today. Will be interesting to see how she manages it all.
THE IMOCA thread, single/double handed & TOR
- Thread starter Fiji Bitter
- Start date
Front page headline on the BBC site today. Will be interesting to see how she manages it all.
jb5
Super Anarchist
Very cool view.
It depends. Even with metal fatigue is a different process depending on alloy type. You build a bicycle out of aluminium and if the tubing diameter is too narrow and the frame flexes - a human who rides hard can break a frame. Built it out of cromoly steel and the tubing diameter can be narrow and wet as a noodle and functionally the frame will never fail from fatigue cycling with a human riding it.
One of the more extreme visible flex you'll likely see are in 787 wings or gliders with extremely high glide ratios. There's nothing inherently wrong with flex as long as they stay within design parameters. With the loads they're putting on the foil - nothing is really without flex.
3to1
Super Anarchist
I've put thousands of hard miles over the years on at least 6-7 aluminum bike frames. good frames, stiff and fast until the inevitable fatigue crack shows up one day, and usually around the bottom bracket in my experience. are you a cyclist/MTB'er?
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Sailbydate
Super Anarchist
European Bloke
Super Anarchist
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We flex carbon dinghy masts a lot and it doesn't seem to bother them. Provided these things are designed and built properly I don't see an issue.
3to1
Super Anarchist
agreed. the integrity of a carbon part is completely reliant on it's manufacturing quality.
I'd guess it's probably safe to say these 60 foils can indefinitely flex significantly without failing. that must simplify matters immensely.
3to1
Super Anarchist
I thought I read that the tip of a 747 wing swings through about a 25 ft. arc between unloaded/loaded.
Yep - in another life had some development work with fluidforming with a large taiwanese HQed company that wanted to push the limit of aluminium frames before carbon composites really became more mass market. Same company also ended up making some of the best monocoque composite frames because they wanted to go all out & invested heavily on molds and composite looms while other European & American firms were trying to "bridge the difference" with lugged headtube, bottom bracket, seatstay/top tube assemblies.
3to1
Super Anarchist
Giant Bicycles by any chance?
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LeoV
Super Anarchist
Did you work on the Giant Anthem 2008 ? A brilliant thin tube set. Still ride it after I abused it a lot. My best bike ever.
There is a vid of Giant and how they build a carbon frame, impressive. And their own cloth weaving factory...
There is a vid of Giant and how they build a carbon frame, impressive. And their own cloth weaving factory...
Nope - 2008 was much later than when we were involved. More involved with the company in late 1990-2000 on TCR frames and ONCE & dealing with UCI.
Also was nice because they continuously improved and also didn't cut corners. Good engineering good manufacturer. Hence why by the mid-2000s their book of OEM business for other big brands was nearly larger than their own name brand. They could build mid tier frames at much higher quality and no more expensive.
Production line was configured like a Japanese automotive line, safe, and didn't work people to death.
Also understood how to invest in the PRC offshoring properly - OEM alloy frames production got big off there. Keeping high end composite, R&D, marketing at home.
Also was nice because they continuously improved and also didn't cut corners. Good engineering good manufacturer. Hence why by the mid-2000s their book of OEM business for other big brands was nearly larger than their own name brand. They could build mid tier frames at much higher quality and no more expensive.
Production line was configured like a Japanese automotive line, safe, and didn't work people to death.
Also understood how to invest in the PRC offshoring properly - OEM alloy frames production got big off there. Keeping high end composite, R&D, marketing at home.
3to1
Super Anarchist
I've had two aluminum TCR's and currently ride a carbon TCR that is a frankenstein build from a frame set. it's a sweet bike.
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That's part of the design process, a part will be designed to hold a given number of cycles, 10^7 cycles often being considered as infinite life as the strength of the material will not evolve much afterwards. Other parameters to take into account are anything that will impact the strength of the material or produce local stress concentration (wear, corrosion, cracks, ...). As Imoca designer don't want to consider the worst case scenario as it would lead to over-weight, they probably accept a certain risk factor.
The most tricky in this process is to obtain good values for the material used. It takes a lot of testing and testing time to produce good values as multiple samples needs to be tested at different stages of the life cycle to produce a relatively good fatigue curve (something like the one below). While it has to be done to qualify a given material in the aeronautics industry, there is no such constrain for boat builders and I wonder how much is based on actual data and how much is based on literature value and real-life experience from previous design.
As they will push the limit, some foils will probably break during the next VG. Not sure anyone sensible is expecting the fleet to come back with all foils intacts.
The most tricky in this process is to obtain good values for the material used. It takes a lot of testing and testing time to produce good values as multiple samples needs to be tested at different stages of the life cycle to produce a relatively good fatigue curve (something like the one below). While it has to be done to qualify a given material in the aeronautics industry, there is no such constrain for boat builders and I wonder how much is based on actual data and how much is based on literature value and real-life experience from previous design.
As they will push the limit, some foils will probably break during the next VG. Not sure anyone sensible is expecting the fleet to come back with all foils intacts.
Francis Vaughan
Super Anarchist
The trouble with aluminium is that there is no safe load where it doesn't propagate cracks. Which is its dark secret. Most other metals you can reason about when cracks grow or not. But aluminium has a use by date that is baked in. (This worries me with the rise of aluminium in car construction. There are good reasons why Jaguar bond and weld their aluminium cars, and don't bolt them. Holes are the enemy. The cars won't rust, which means they may last a very long time - where cracks might become the dominant failure - which isn't a happy thought if you own one.)
Carbon of course is nastier in some ways. More complex to design and reason about the fatigue life, and subject to sudden catastrophic failure when it does let go. But silly strong when you get it right.
Always had a soft spot for steel tube bikes. There was probably a bit more mileage in the technology, but carbon killed them off. But carbon bikes have a use by date as well, which steel didn't. (I still have a vintage Reynolds 531 framed road bike.)
Carbon of course is nastier in some ways. More complex to design and reason about the fatigue life, and subject to sudden catastrophic failure when it does let go. But silly strong when you get it right.
Always had a soft spot for steel tube bikes. There was probably a bit more mileage in the technology, but carbon killed them off. But carbon bikes have a use by date as well, which steel didn't. (I still have a vintage Reynolds 531 framed road bike.)
jb5
Super Anarchist
There are a series of short videos and photos in the IG post. Can't find them elsewhere. They are doing speed runs and the noise level is huge. Looks like fun.
jb5
Super Anarchist
https://instagram.com/stories/charalsailingteam/2121299667502140893?utm_source=ig_story_item_share&igshid=1ijb8iwg3utah
Another IG from Charal today. You probably need an IG account to see it.
Another IG from Charal today. You probably need an IG account to see it.
jb5
Super Anarchist
Nope it's not the new boat but Jean Le Cam's ex Foncia rebranded for the TJV.
jb5
Super Anarchist
https://www.scanvoile.com/2019/08/skippers-imoca-classe-action-developpement-durable-programme-climat-education-.html#.XWkHh0DYphE
Sailing is clean sort of....
Google translation.
The IMOCA class and its riders commit themselves to sustainable development
Major support of the Call for a "Common Ocean of Humanity" and signatory of the commitment letter "Sports for Climate Action", the IMOCA class has set up its own "Oceans Program", proposing concrete actions . Overview of actions taken by the class, runners and organizers, in favor of sustainable development.
"Oceans Program", an action plan
Sailors are the first witnesses of the global impact of man on this essential and fragile environment. The time is no longer in the report, but in action. This is why the IMOCA class is setting up an "Oceans Program" to reduce the impact of projects and to disseminate positive and positive messages. The action plan is based on four themes (events, ecological transition, awareness and science).
IMOCA continues to support the Ocean As Common program
The IMOCA class is a support from the first hour of the Call for an "Ocean, common good of Humanity", launched on June 8, 2018 during the Monaco Globe Series. To formalize this partnership, the Class signed a sponsorship agreement with Ocean As Common one year later, in order to support its message and accompany its actions during IMOCA events.
The signatory class of the UN Charter "Sports For Climate Action"
IMOCA is one of the sports organizations that has joined a new climate movement in the world of sport. The signatories of the Sports For Climate Action Charter commit to adhere to a set of five principles and integrate them into their strategies:
Undertake systematic efforts to promote greater environmental responsibility
Reduce the global climate impact
Educate to action climate
Promote sustainable and responsible consumption
Advocate for climate action through communication.
Sailing is clean sort of....
Google translation.
The IMOCA class and its riders commit themselves to sustainable development
Major support of the Call for a "Common Ocean of Humanity" and signatory of the commitment letter "Sports for Climate Action", the IMOCA class has set up its own "Oceans Program", proposing concrete actions . Overview of actions taken by the class, runners and organizers, in favor of sustainable development.
"Oceans Program", an action plan
Sailors are the first witnesses of the global impact of man on this essential and fragile environment. The time is no longer in the report, but in action. This is why the IMOCA class is setting up an "Oceans Program" to reduce the impact of projects and to disseminate positive and positive messages. The action plan is based on four themes (events, ecological transition, awareness and science).
IMOCA continues to support the Ocean As Common program
The IMOCA class is a support from the first hour of the Call for an "Ocean, common good of Humanity", launched on June 8, 2018 during the Monaco Globe Series. To formalize this partnership, the Class signed a sponsorship agreement with Ocean As Common one year later, in order to support its message and accompany its actions during IMOCA events.
The signatory class of the UN Charter "Sports For Climate Action"
IMOCA is one of the sports organizations that has joined a new climate movement in the world of sport. The signatories of the Sports For Climate Action Charter commit to adhere to a set of five principles and integrate them into their strategies:
Undertake systematic efforts to promote greater environmental responsibility
Reduce the global climate impact
Educate to action climate
Promote sustainable and responsible consumption
Advocate for climate action through communication.
With aluminium alloy structures, the key is to over engineer the structural stiffness so the # of cycles to failure is as high as possible & build in defect detection before catastrophic failure.With the extremely stiff space frames being used on luxury/sports cars with relatively few expected miles - prob safe to say they'll last longer than any of the electronic and wearing components will & be safe in a garage somewhere.
