Maybe all test engineers think alike. Generally we look at causitive
actions. Mostly we work from FMEA (Failure Modes and Effects Analyses) as
starting points. In high value programs we try and think of every failure
that could happen, determine its results, then if risk is high, mitigation
methods. In this case risk is high. As to "it failed", what are the
causitive actions that can occur? Canopy blow apart? Shroud lines Tangled?
Broken shroud lines? Broken Tow? Broken attachment? Failure to deploy? Most
as you can see have to do with some sort of tensile failure in materials.
Most ductile materials function very well under static loading or slowly
loading situations. But when the load rate or strain rate goes very high,
they fail in a brittle manner. The material just comes apart when other wise
it would hold up very well. Sortas like hanging. Put a noose around your
neck and slowly pull you up and you most likely wont have a broken neck. But
drop about the length of a person and the Yank loads cause neck snaping. So
it is all relative. Sky dvers sometimes experience 6 g's of yank when their
chutes open and they are going pretty slow compared to most streamliners.
As to high cylinder pressures...how much juice you running? Pretty easy to
do an otto cycle engine analysis when set up on spread sheet.
mayf
----- Original Message -----
From: "Joe Amo" <jkamo@rap.midco.net>
To: "DrMayf" <drmayf@teknett.com>
Cc: <Nt788@aol.com>; <webmaster@landracing.com>; <gmc6power@earthlink.net>;
<landspeedracer@msn.com>; <kturk@ala.net>; <land-speed@autox.team.net>
Sent: Tuesday, October 22, 2002 3:11 PM
Subject: Re: Parachutes
> Mayf, respectfully with a statement like:
>
> ""it failed. don't need to know much more, do I?""
>
> I gotta ask, do all engineers think alike??:):):)
>
> seriously, thank you for the insight and calculations
> you provide
>
> you got any for my engine (joking), I hear that cylinder pressures can
> get real
> high (joking)
>
> Joe :)
>
> DrMayf wrote:
>
> >it failed. don't need to know much more, do I? And never said I knew
what
> >was wrong at any time or any point. Just that parachute loads are very
high
> >when deployed in the manner they are and that can and does lead to
failures.
> >However, any weak link in the system will rupture at high loads rates
like
> >these.
> >mayf
> > ----- Original Message -----
> > From: Nt788@aol.com
> > To: webmaster@landracing.com ; gmc6power@earthlink.net ;
> >landspeedracer@msn.com ; drmayf@teknett.com ; kturk@ala.net ;
> >land-speed@autox.team.net
> > Sent: Tuesday, October 22, 2002 9:05 AM
> > Subject: Re: Parachutes
> >
> >
> > In a message dated 10/19/2002 9:40:47 PM Pacific Daylight Time,
> >webmaster@landracing.com writes:
> >
> >
> > Mayf, how can you say what might be wrong when you have not inspected
the
> >failure of the chutes at any particular occasion
> >
> >
> > THE BEST STATEMENT YET! JACK
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/// what is needed. It isn't that difficult, folks.
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