Anthony:
Yes, I am looking at an FEA comparison that clearly shows countersunk
fasteners requiring fewer piece parts at (very slightly) greater total
weight.
If I am missing something here I’d like to technically understand it.
Tradition is not a technically valid reason for doing a thing....
Bill
On Wed, Dec 18, 2019 at 6:31 PM Anthony Cesaroni <anthony@xxxxxxxxxxx>
wrote:
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/
(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>
wrote:
Yes. Just use pins and leave it at that.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
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 8:06 PM
*To:* 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