Amateur Ornithologist - Mechanical Engineers Chime In on the Structure of a Feather
As you might remember, the last time we were looking at the structure of a feather. I asked for help from an old chum (and mechanical engineer), and his thoughts follow...
I found this: http://jeb.biologists.org/cgi/reprint/201/22/3057.pdf
It contends that the strength of the feather's stem is largely due to the cortex, and hence, the cross section of the stem. You may want to cut the feather stem and start looking at the cross section, and then compare the cross-sectional interior of the shape to common structure shapes (like T-bars, I-bars, tubes - things like that).
-Alec
To speak to Alec's thoughts concerning the cross section of the feather... Unfortunately, in trying to cut the feather, I deformed it. But under magnification, it looks like this:
(Yeah, I know... I stink as an artist. But you get the idea.)
Judging by what the authorities have to say, it appears that the common feather straddles the fine line between the ability to repeatedly flex and the strength not to buckle.
(Anyone who would care to explore the issues of compression and tension on the surfaces of the sheath of the rachis spine (which covers the keratin core) of a feather should use the "Comments" button below. I'd like to delve into this deeper, but if I did, someone would probably throw a rock at me!)
See you by the feeders... (And watch out for that next contest, because you guys are all going to have to work together or NO ONE gets a shot at the prize!)
CapeCodAlan