is it ok to revive this thread now with tidbit about BFR, or whatever you want to call it now, is to be made of metal?thoughts on design change or too early?jb
Quote from: jabe on 12/09/2018 03:04 pmis it ok to revive this thread now with tidbit about BFR, or whatever you want to call it now, is to be made of metal?thoughts on design change or too early?jbI don't understand why you'd want to discuss it in this thread instead of the BFR thread.
Also fittings inside the starship like the decks, supports etc
Quote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe not
Quote from: Jim on 12/10/2018 03:19 pmQuote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe notWhy would carbon fibre not be a suitable material for decks and supports?
Quote from: Slarty1080 on 12/10/2018 03:42 pmQuote from: Jim on 12/10/2018 03:19 pmQuote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe notWhy would carbon fibre not be a suitable material for decks and supports?Something out of the left field:Metal may be a lot more useful for REuse/recycling once it is landed mass on an other planet.
Quote from: Slarty1080 on 12/10/2018 03:42 pmQuote from: Jim on 12/10/2018 03:19 pmQuote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe notWhy would carbon fibre not be a suitable material for decks and supports?Metal has lower fire risk, I guess.
Quote from: Slarty1080 on 12/10/2018 03:42 pmQuote from: Jim on 12/10/2018 03:19 pmQuote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe notWhy would carbon fibre not be a suitable material for decks and supports?If they use metal for the hull, they may need interior structure compatible with expansion/contraction in contact with hull. Slip joints might not provide enough structural support.
Quote from: Ionmars on 12/12/2018 09:46 amQuote from: Slarty1080 on 12/10/2018 03:42 pmQuote from: Jim on 12/10/2018 03:19 pmQuote from: Slarty1080 on 12/10/2018 10:35 am Also fittings inside the starship like the decks, supports etcMaybe notWhy would carbon fibre not be a suitable material for decks and supports?If they use metal for the hull, they may need interior structure compatible with expansion/contraction in contact with hull. Slip joints might not provide enough structural support.compatible how? the crew compartment needs to remain at human temperatures and therefore is basically immovable, not subject to expansion/contraction as far as the hull is concerned, whether carbon fiber or metal.
Human temperatures are a 100 degree F range though. That is about half an inch of expansion over 9 meters of Aluminum. He is right that carbon fiber shrinking (assuming the fibers are circumferential around the tube) and the aluminum internal structure expanding could be a problem. It may make the structure unusually vulnerable to off nominal thermal stress. That being said, mixing composites and metal structures is of course done on Falcon 9 - at a smaller scale though, and the composite interstage did fail on the recent booster. Whether thermal stress had something to do with that? Not sure.