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Office Chair
Failure
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Metallurgical failure analysis was necessitated as
result of an office chair failure. Visual and metallurgical examination
revealed cracks in the office chair base. Visual
inspection revealed that the office
chair had been previously cracked and had been re-welded
over the previous crack. Re-welding without removing the
initial cracked metal is very poor repair practice..
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| Overall view of subject office chair. | |
Close-up view of
bottom/underside of
re-welded office chair.
After additional
usage of the repaired office chair, the weld repair also failed. Normally re-welding of a
metallurgical failure will melt the original
cracked metal and will make any meaningful
metallurgical failure analysis impossible. However, if
the re-weld also fails, the possibility exists that
significant metallurgical fracture evidence from the
original cracking/failure event might be
uncovered if the cracked weld is opened and evaluated. A metallurgical failure analysis and design
evaluation was conducted. However, in this matter,
the failure analysis of the
failed office chair was concluded without metallurgical
or weld testing.
Close-up view of center line weld crack in
re-welded office chair base.
Close-up view of cracking in re-welded
office chair base.
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Dr.
R. Craig Jerner, Ph.D., PE specializes in accident
investigation and metallurgical failure analysis,
with over 30 years experience as a metallurgical
consultant and accident investigator. He has
testified as a metallurgical expert in over 250
depositions and more than 70 court appearances. If you or someone you know should need the services of Dr. Jerner and J.E.I. Metallurgical, please visit our web site at the buttons below, or e-mail Dr. Jerner --- 