Return-Path: Sender: (Marvin Kaye) To: lml@lancaironline.net Date: Sat, 27 Mar 2004 18:16:10 -0500 Message-ID: X-Original-Return-Path: Received: from imo-d22.mx.aol.com ([205.188.144.208] verified) by logan.com (CommuniGate Pro SMTP 4.1.8) with ESMTP id 3125677 for lml@lancaironline.net; Sat, 27 Mar 2004 11:59:20 -0500 Received: from Sky2high@aol.com by imo-d22.mx.aol.com (mail_out_v37_r1.2.) id q.1ec.1c631ee4 (3972) for ; Sat, 27 Mar 2004 11:59:18 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: <1ec.1c631ee4.2d970ce5@aol.com> X-Original-Date: Sat, 27 Mar 2004 11:59:17 EST Subject: Re: [LML] e-glass vs carbon fiber X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1080406757" X-Mailer: 9.0 for Windows sub 810 -------------------------------1080406757 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 3/27/2004 10:37:52 AM Central Standard Time, marv@lancaironline.net writes: I am suspicious that this could lead to problems due to the differing stiffness of the two. When a structure like that is put under load, the stiffer material carries more of the load and there becomes a large stress where the different materials join. Maybe someone has tested this and can make a recommendation for us all. Mark, With respect to 320/360s, we are all testing this every day - our spar caps have carbon fiber enclosed by pre-preg glass and the webs are pre-preg glass, not to mention the that the spars are bonded/glassed to the glass wing skins. I would think that, in the spar cap case, the stiffer core material would put less stress on the more flexible encasement and web material. Also, those that fly under the forward hinged canopy used uni-directional carbon fiber layups between the canopy skin, foam and pre-preg glass to stiffen the forward part that is under stress from the gas struts. Aye, she's still holding together! Scott Krueger -------------------------------1080406757 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 3/27/2004 10:37:52 AM Central Standard Time,=20 marv@lancaironline.net writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>I am=20 suspicious that this could lead to problems due to the differing
stiff= ness=20 of the two. 
When a structure like that is put under load, the=20 stiffer material carries
more of the load and there becomes a large st= ress=20 where the different
materials join.
Maybe someone has tested this a= nd=20 can make a recommendation for us all.
Mark,
 
With respect to 320/360s, we are all testing this every day - our spar=20= caps=20 have carbon fiber enclosed by pre-preg glass and the webs are pre-preg glass= ,=20 not to mention the that the spars are bonded/glassed to the glass wing=20 skins.  I would think that, in the spar cap case, the stiffer core mate= rial=20 would put less stress on the more flexible encasement and web material. = ;=20 Also, those that fly under the forward hinged canopy used uni-directional ca= rbon=20 fiber layups between the canopy skin, foam and pre-preg glass to stiffen the= =20 forward part that is under stress from the gas struts.  Aye, she's stil= l=20 holding together!
 
Scott Krueger
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