BTW have you seen the comparison of a pin versus a counter sunk fastener in a
composite? An FEA validates nicely in practice.
Pins.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
<http://www.cesaronitech.com/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf Of
William Claybaugh
Sent: Wednesday, December 18, 2019 8:21 PM
To: arocket@xxxxxxxxxxxxx
Subject: [AR] Re: Composite Fastners
Anthony:
Why?
Pins are typically one time use and thus no help when one is fitting up parts.
Countersunk fasteners—with some care around torque—offer far more bearing
surface and can be reused. What is the presumably economic reason for using
more pins and going with direct assembly w/o fit-up of the parts?
Bill
On Wed, Dec 18, 2019 at 6:11 PM Anthony Cesaroni <anthony@xxxxxxxxxxx
<mailto:anthony@xxxxxxxxxxx> > wrote:
Yes. Just use pins and leave it at that.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
<http://www.cesaronitech.com/> http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
From: arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx>
<arocket-bounce@xxxxxxxxxxxxx <mailto:arocket-bounce@xxxxxxxxxxxxx> > On Behalf
Of William Claybaugh
Sent: Wednesday, December 18, 2019 8:06 PM
To: arocket@xxxxxxxxxxxxx <mailto:arocket@xxxxxxxxxxxxx>
Subject: [AR] Composite Fastners
The aluminum tube in my recent 6” static test weighed 13.9 lbsm.; a similar
Carbon fiber tube in my possession weighs 5.5 lbsm and is tested to burst at
almost twice the aluminum tubes’s burst pressure....
So I’m looking at composite tubing: I observe that the rocket industry pretty
much universally uses pins as fasteners, yet pins are the least strong choice,
analytically.
Is there some obvious—or not—reason that I should not be using a countersunk
fastener with a composite tube?
Bill