OK, I may be pulling some sacred chains here; but IMHO these drag racers and
their NHRA are a "ship of fools". That computer analysis of the dragster
frame is a sad joke. Especially sad because it shows the state of their
engineering knowledge of this complex engineering problem. Anyone with an
exposure to a first undergraduate course in ferrous (steel) metallurgy will
see the absolute folly in what they are doing allowing the use of a heat
treatable alloy like 4130 for their frames. They have absolutely no
quantifiable idea of the cyclic stresses that these chassis encounter in the
racing environment and the variablity of steel properties in the resulting
fatigue environment, let alone the chassis vibation modes that agravate the
chassis loadings. Add to that the inconsistencies in welding and thermal
stress relieving of a large structure like a chassis. Then add the
variability in material properties as the structure passes through the range
of low cycle fatigue (which require a far more sophisticated finite element
stress analysis routine).
These fools need to follow the wisdom of the SCTA and force everyone back to
the engineering simplicity of low carbon steel. Messing with chrome moly
frames in a sport where everyone feels compelled to push the limits even if
they don't understand them and are hopelessly incompetant to cope with them
is total folly. Nascar learned the hard way to "throttle back" the
performance of their race cars to something manageable from a safety
standpoint. It sure didn't hurt their business model in the long run. NHRA
will have to do the same. There's a lesson in that for all of us.
Ed Weldon
----- Original Message -----
From: "Bill Bennett" <bennevl@bellsouth.net>
To: <land-speed@autox.team.net>
Sent: Tuesday, October 23, 2007 5:11 PM
Subject: [Land-speed] NON LSR Interesting read
> I will let each one of you make your own minds up on this one. Looks like
> choosing profits over safety to me.
> When the SFI spec says one thing and half the cars don't meet the SFI spec
but
> still allowed, I call FOUL.
>
http://competitionplus.com/index.php?option=com_content&task=view&id=4358&Ite
> mid=24
> Bill
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