<VV> Good Ref re strength of bolts

[John Kepler]

An interesting article by an apparently qualified engineer -- sometimes 
it is a shame that qualified engineers can not see beyond the 
mathematics of their profession 


And your "empirical evidence" is what exactly?  Somebody's WAG on what
actually happened?  Your above statement is why cops, prosecutors, and
juries don't like "eye-witness" testimony and prefer forensics...."empirical
evidence" is often about as valid, useful, and factually consistent as the
ejecta from the north-end of a south-bound horse!  Numbers are hard to argue
with, and until you have some of your own...all you have is a working theory
at best, a WAG at worst, and nothing really significant to say.

BTW, durability cycles are part of the spec of ANY device....a part, (that
includes a fastener), has a designed nominal cycle-life (read that as the
number of times the part is subjected to its design load....in the US auto
industry, the nominal and generally tested cycle-life is 1 million cycles)
based on the design conditions (read that as "torque" and "load" in this
case)....exceed that cycle-life and/or alter the design conditions, and the
part (fastener) will fail.  Mechanical Engineering 101!

Corvair content:   Every fastener in our Corvairs has exceeded its
"design/cycle-life" by several orders of magnitude and is a
"failure-in-progress" as a result.  All "critical" original fasteners (read
that as suspension fasteners for openers) should be replaced.  But remember,
this is just advice from one of those "... qualified engineers (that) cannot
see beyond the mathematics of their profession"...so what the hell do I
know!

"If you can't express it in numbers, it's an opinion, not a fact!"  Dr. T.J.
O'Keefe, PE

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