Date:         Wed, 2 Mar 2011 18:31:39 -0500
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Metal inserts slide out? Easy fix.
Comments: To: Jake de Villiers <crescentbeachguitar@gmail.com>
In-Reply-To:  <AANLkTi=KU1vbdgBxkg6xJjC_eexUxERACw5vkYie8Wjy@mail.gmail.c om>
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At 01:16 AM 3/1/2011, Jake de Villiers wrote:
>Hmm.  When I re-did Dixie's pipes I put a couple or three rivets
>into each insert after the heat and beat treatment.  I really don't
>see how there could be any stress risers created in the holes since
>the rivets are a compressive force on the flat plastic.

The plastic isn't flat, of course; it's a ~3/4" radius circle.  But I
was curious about this so I did a little checking on a piece of 1/8"
acrylic and found the results interesting.  Have a look at
https://picasaweb.google.com/dbeierl/StressInPlasticFromPopRiveting#
.  I'd expect the effect to be more pronounced since the pipe isn't
flat, but the propagation distance to be less because of the material.

Yours,
David