what happens when a wire breaks under
tensile load exceeding its strength. It's
typically recognized by the "cup
and cone" appearance at the point
of failure. The necking down of the wire
at the point of failure to form the cup
and cone indicates failure has occurred
while the wire retained its ductility.
a wire with a distinct fatigue break.
It's recognized by the square end perpendicular
to the wire. This break was produced by
a torsion machine that's used to measure
the ductility. This break is similar to
wire failures in the field caused by fatigue.
wire rope that has been subjected to repeated
bending over sheaves under normal loads.
This results in fatigue breaks in individual
wires -- these breaks are square and usually
in the crown of the strands.
of fatigue failure of a wire rope subjected
to heavy loads over small sheaves.
The breaks in the valleys of the strands
are caused by "strand nicking."
There may be crown breaks, too.
you see a single strand removed from a
wire rope subjected to "strand nicking."
This condition is a result of adjacent
strands rubbing against one another. While
this is normal in a rope's operation,
the nicking can be accentuated by high
loads, small sheaves or loss of core support.
The ultimate result will be individual
wire breaks in the valleys of the strands.