I was wondering whether I should mention that. :-)
~Jon
On Mon, Dec 28, 2015 at 3:48 PM, Rand Simberg <simberg@xxxxxxxxxxxxxxx>
wrote:
Of course, that was theoretical. This is becoming real. I do remember
HEAVY FREAKING LOADS, though. ;-)
On 2015-12-28 14:45, Jonathan Goff wrote:
Oh come on, I remembered bringing up fatigue issues for RLVs back in
the late 90s on the sci.space.* usenet groups... ;-)
~Jon
On Mon, Dec 28, 2015 at 3:43 PM, Rand Simberg
<simberg@xxxxxxxxxxxxxxx> wrote:
Am I the only person who is excited that we're seriously discussing
fatigue as a thing in a launch system?
On 2015-12-28 14:35, David Weinshenker wrote:
On 12/28/2015 02:18 PM, Henry Spencer wrote:
The
tough part would be the very dynamic things, like acoustic and
vibration
loads.
Yeah, I can think of ways to -expose- "dynamic" fatigue
sensitivity - e.g,, instrument the amplitude as well as
the force of the exciter interface to the "system-under-
vibration-test", and sweep the excitation frequency looking
for features in the impedance that suggest resonances at
certain frequencies - then lean on those frequencies
watching especially for shifts in the impedance suggesting
that some degradation (cracking, work-hardening, etc.) is
occurring.
With a nasty enough mentality and a powerful enough vibration source
you should be able to make something crack -somewhere-; the question
then becomes the correlation between this observation and the
expected
operating stresses. (I suppose one could adopt the philosophy of
fixing
the fatigue resonances wherever they appear, whether or not they
would
be excited by "expected" flight loads.)
-dave w