system works on the principles of potential drop in an electric
circuit. The crack gage has an adhesive file on the back and can
be easily mounted on the DCB specimen. The crack locator gage
attaches to the component board via the ribbon cable and the adapter.
A crack propagation beneath the gage induces local fracture of
the sensing strands on the gage. The system box continually sends
signals to the onboard computer on the test machine and at any
given time the crack length and the location of crack is directly
proportional to the voltage signal read by the test machine computer.
The LEDs located on top of the system box in tracking the crack
visually while the experiment is still in progress. The systems
can be used on DCB specimens of varying thickness and length.