I am trying to determine the best composite to use for a Mars Manned Exploration Vehicle. The main structure will be a kevlar (or zylon?) cylinder, 8’ wide, 17’ long and 3/4" thick (guessing on the thickness). It will need to support its own weight as well as 4,000 lbs (earth weight) of additional equipment and withstand temperatures of -80 degrees F to 70 degrees F. The internal pressure will be 5 psi. There will be two pressure bulkheads at the rear that make up the depressurization area for outside excursions. I would like to know the weight of this structure and cost. If you would like to see the post on the entire idea go to:
I’ve built parts that are on Mars right now and none of them are made of kevlar. If you want strength you need to make out of graphite.
When you say carbon do you mean carbon reinforced fibers added to a composite like in F-18 wings? Can you make an entire cylinder out of carbon fiber? Also how would that compare in cost to kevlar construction? More importantly do you have a weight estimate?
Sure you can. Kevlar is better suited against impact but carbon fiber yields better stiffness. Overall weight would depend on your choice of core material. You might not want to create the entire tube out of graphite alone. You want something similar to F1 car bodies which are reinforced with honeycomb core.