Hi All,
Just a short take on the ongoing debate about the failure of these upper
control arm bolts. One should be able to tell from the broken surface what
method of failure has occurred. If the bolt failed in tension then the
bolt shaft would appear stretched and would likely have a conical end where
it was pulled apart. A shear failure would appear as if someone had cut
the bolt with a knife, although the edges would be rough. The initial
message stated that half of the bolt had been rusted through. This would
suggest crack propagation through the remainder of the bolt and would look
like a shear failure even if the applied tensile load caused the eventual
breakage. The result is similar to that plane that had its top ripped off
on a flight to Hawaii if any one recalls that incident. Even if the bolt
itself is in strong tension, it can fail in this manner. If anyone is
curious they might try destroying bolts as Tom Walter suggested earlier and
they will see the conical deformation present when a steel bolt fails in
tension. (Although there will obviously be some twisting associated with
this method.) Adios,
Rich
1970 SPL311 (just got it!)
Richard James
Aerospace & Mechanical Engineering
Building #119 Room N614
The University of Arizona
Tucson Arizona 85721
richard@u.arizona.edu
phone (520) 621-9106
FAX (520) 621-8191
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