Return-Path: Received: from ddi.digital.net ([198.69.104.2]) by truman.olsusa.com (Post.Office MTA v3.1.2 release (PO203-101c) ID# 0-44819U2500L250S0) with ESMTP id AAA18010 for ; Thu, 24 Sep 1998 19:36:35 -0400 Received: from john (max-roc1-21.digital.net [206.228.234.21]) by ddi.digital.net (8.9.1/8.9.1) with SMTP id TAA06343 for ; Thu, 24 Sep 1998 19:36:29 -0400 (EDT) Message-Id: <3.0.3.32.19980924193440.006de1b8@mail.digital.net> Date: Thu, 24 Sep 1998 19:34:40 -0400 To: lancair.list@olsusa.com From: John Cooper Subject: Carbon vs. Glass X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Scott-- Yeah, yeah, I've heard all that before... But what about the Young's Modulus of the spruce longerons (E=1,500,000) vs. the Young's Modulus of the fiberglass fuselage (E=10,600,000), hmmm? This is a much bigger ratio than between glass-epoxy and carbon fiber (E=35,000,000). Shouldn't the "stiffer" glass-epoxy fuselage break before the spruce longerons in the standard design? And wouldn't the epoxy (E=2500) joining the two layers fail long before either the glass-epoxy or the carbon fiber failed? Yes, the worst that will happen to my plane is that cracks develop where the epoxy holding the carbon fiber to the pre-preg fails in shear, in which case I am back to the "standard" strength and will have to repaint my plane.