Re: Re: GRP

On Feb 17, 2006, at 3:44 AM, Steve McKenzie wrote:

> That USACE report was quite a good read.
Ain't that the truth. A lot more direct than you'd expect. Since the days of flying cars and 'futurists' touting nuclear power as so cheap it wouldn't be worth billing for, I've always been pretty leery about miracle breakthroughs and materials that would be all things to all applications. FRP is great stuff for a lot of things, but it's been way oversold. The one thing to remember about plastics of any sort is that the material characteristics are strongly dependent on the part you make it into--the material isn't created until you've created the part. That makes strength determination a little bit tricky, because you don't know how strong the part is before you've actually tested a couple of them. The second thing about plastics is that they're nothing like as stable as structural metals. Environments which we think of as benign can be very damaging to plastics, and very small loads can cause permanent set. You don't simply design something to be made from plastic without understanding the behavior of the material you're planning to use, and especially you don't convert from a metal part to a plastic one willy-nilly.

Christopher Wright P.E. |"They couldn't hit an elephant at chrisw@skypoint.com | this distance" (last words of Gen.

.......................................| John Sedgwick, Spotsylvania