|
Chevron Marks
Chevron marks
are often left on a fracture surface as a result of
a fracture process. 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 origin for the portion of the crack is
located to the left of Photograph A

Photograph
A Chevrons pointing from right
to left
indicating the origin of the fracture
lies to the
left of 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
Chevrons in hardened case
of a turntable bearing
point to the right
indicating a fracture origin to
the right of
Photograph B.
|