For problems that are rather
complicated and have hardware available, we can often simply
instrument the actual part and subject it to all types of
loading right in the laboratory. This is a very direct, economical approach and always succeeds
in conveying the integrity of the new design to management
and others. We
can also create the physical model to test right in our
prototype machine shop, if needed.
include strain gages, deflection gages, and photoelasticity.
Each has its own strengths and each is inexpensive to
Strain gages are bonded on
resistive elements that are already calibrated to give
strain values after wiring up.
They give complete information on the strain field at a
specific location. We can also measure residual stress
and strain using strain gages.
Deflection gages are for
overall deflection data.
These can be individual dials or transducers wired
right into our data acquisition system.
fascinating to observe and provides a “full-field”
solution, enabling the engineer to have a quantitative map
of the entire stress field for the part in question.
This is very powerful, especially for new parts, or
for old part being loaded in new ways.