printable version
A complete
fracture toughness test can be performed on compact tension
specimens with the Fatigue Dynamics FTS-6000. Or a Fatigue Dynamics
precracking machine can free up your universal test machine by
performing the more time-consuming task of initiating the required
fatigue crack at the root of a notched specimen.
Procedure:
Fatigue cracking loads are input by adjusting
the crank stroke of the machine. As the specimen begins to crack, load decrease is
detected by the SC-6 Shutdown Controller. (Fatigue cracks also may be observed visually or
a predetermined number of fatigue cycles may be entered into the cycle counter to stop the
machine to ascertain whether the desired crack length has been achieved.) Once the crack
has propagated to the desired length, the specimen is installed in a universal test
machine to complete the fracture test.
Equipment, Methods, Accessories:
The FDI-2000 and FDI-6000 Precrackers
are designed to perform fatigue cracking of COMPACT TENSION specimens.
FDI-2000 has a maximum tensile force capability of 2000 Ibs, and a speed of up to 2400
cycles/minute. FDI-6000 can provide up to 6000 lbs. of force and a max. of 2000 CPM. The
load cell in each machine allows for static setup of the desired load as well as
monitoring the load during the fatigue cracking process. Special specimen grips and
alignment joints are available.
The FDI-4000 Precracker performs fatigue
cracking of single-edged (3- point bend) notched specimens. Capacity up to 4000 lbs.; 200
to 2400 cycles/minute. The load cell can be repositioned to reduce the maximum capacity to
1500 lbs., increasing the low end load resolution for smaller specimens during setup and
specimen cracking procedures. (Note use of the Fatigue Dynamics LFE Test Base; by
installing other available test fixtures, a variety of fatigue tests can be
performed.)
