Expert Witness Blog
Expert witness R. Craig Jerner describes metallurgical failure analysis in automobile accidents. “When an automobile accident happens, the question frequently arises did the wheel, axle, steering, spring, bolts, frames, brackets, or screws fail causing the accident, or did the impact forces of the accident cause the failed/broken component to break. Metallurgical failure analysis and/or root cause analysis is often required to provide the answer.”
Jerner describes a pickup rollover accident and his failure analysis expert witness findings:
The right rear wheel of a pickup was found nearby the vehicle after a rollover accident. The “mag wheel” failed in the spokes and welded spoke attachment feet. Two other “mag” wheels on the subject pickup were also observed to be fractured. Did the wheel loss cause the rollover or was the wheel loss a result of the rollover?
Inspection showed that welding design and welding defects present in the subject “mag wheel” were not the cause of this rollover accident. Examination of skid marks and the lack of roadway gouges precluded the accident being the result of wheel rim failure. Axle failure and wheel loss were the result of forces experienced during the rollover, rather than wheel loss causing the truck to rollover.
For more see: http://www.metallurgist.com/index.html