Residual stresses are the
stresses that remain after external loading has been removed. Any deformation
or annealing process can generate residual stresses. The total stresses on a
component are the sum of residual and applied stresses.
Compressive stresses (negative)
are generally desirable as they typically increase fatigue life and inhibits
stress corrosion cracking while tensile stresses (positive) adversely affect
the performance of a component.
Our equipment is engineered for
laboratory quality measurements with maximum flexibility; most of our equipment
is portable, allowing for the measurement of samples as small as 300um in width
up to a ship or active bridge and everything in between.
Incoming x-rays are absorbed
and re-emitted by each atom in a small volume near the surface. The periodic
arrangement of the atoms creates a distinct pattern in the re-emitted x-rays
following Bragg’s law. By looking at a single peak of that pattern and how it shifts
based on tilting relative to the sample normal we can measure a
crystallographic strain. Then using Hook’s law and linear elastic properties of
the material the residual stress in a specific direction can be calculated.
Yes, as opposed to large
laboratory machines with maximum power exceeding 1000w, XStress systems use a
relatively small 300w maximum power along with comparatively short shutter open
times of seconds versus minutes to hours. In addition, all the equipment meets
and exceeds ANSI N43.3-1993 standard s for open beam operation. Without a
safety enclosure safe operating distance in most places is ~6ft. With an
interlocked safety enclosure safe operation in the laboratory is easily