Chevron Marks

Chevron marks are often left on a fracture surface. Most usually, they occur as a result of running fractures, i.e., fractures which progress through the structure. Chevron marks are extremely helpful to the failure analyst. Chevrons point to where the crack came from, i.e., where the crack ultimately originated.

A clear set of chevron marks is shown in Photograph A. The chevrons in Photograph A point from right to left indicating the fracture origins for the portion of the crack is locating to the left of Photograph A


Photograph A

Chevrons, in the hardened zone (lower smooth fracture) of a turntable slewing bearing fracture are shown in Photograph B. The chevrons in the hardened bearing case clearly indicate (point) to the right. Therefore, this particular crack originated to the right in Photograph B.


Photograph B

 

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 --- r.c.jerner@metallurgist.com


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