Quote:
Originally Posted by freebeard
|
Thanks
mucho, Freebeard, that helps a bunch. I just finished a class on advanced composites, with emphasis on vacuum infusion and carbon fiber. Unfortunately, carbon fiber is expensive, labor intensive, and error prone on application. It does not like to wet out as well as other composites, so the selection of resins is somewhat more limited and expensive. It's also somewhat fragile and brittle, and can shatter on impact, so its lack of toughness means it needs Kevlar or other such facing to protect the ride in, say, a streamliner recumbent bike. (Shards of carbon fiber could be dangerous when the bike falls over, trapping the rider in a sort of cheese grater.)
I'm very curious about this new wood pulp composite, especially
which particular wood.
Some types of wood have much better fatigue strength than metals. Stiffness and fatigue strength are what engineers must design around, since we don't want the car to break when the metal gives out, so more metal is put in on construction, to offset and prevent the anticipated failure. In other words, much of the metal is dead weight.
Bamboo (esp. stronger varieties such as Tonkin, used for fishing poles) is said to have nearly the stiffness of carbon fiber, is tougher, vastly cheaper, and is excellent as a vibration dampener, so would make a quiet riding vehicle. Bamboo is actually a grass, and grows vastly faster than wood, sometimes several feet per day, and is much more environmentally useful than hardwoods, metals, or composites. It's stronger than oak and harder than maple, hence its growing popularity for flooring. Has natural antibiotics to resist jungle rot, etc..
I wonder about using bamboo leaves (being flat) for oriented strand board, which might be steam/pressure formed into compound curved parts.
Bamboo can be steamed or heated and bent somewhat. YouTube for it.
Hemp fibers are also a good candidate for composite structures, very tough and strong, and very cheap. Henry Ford is said to have tried hemp composite for use as car fenders in the 1920s or '30s, of course rust proof, and pretty tough and comparatively impact resistant.