MTS Fracture Template - Manual (Page 46)

Description Parameter
Specify the percentage of the measured load
range used as the upper limit for linear least Precrack Upper Least
Squares Fit Percentage
squares fit compliance determination. This
parameter is not used for FCG DCPD tests.
Specify the percent of maximum load level
at which the voltage is measured. The load Precrack Measure Load
Level Percent
is applied at this level to ensure the crack is
open. All voltage data below this load will not
be used to calculate crack length. This
parameter is used only for FCG DCPD tests.
Specify the number of cycles at which
precrack activity stops. Precrack Cycle Limit
Specify the maximum stress intensity desired
at the end of precrack activity. The initial Precrack Final Maximum
K
precrack Maximum K is 1.4 times the Final
Maximum K value.
Select Yes to cause an interlock at the end
of precrack. This can shut down hydraulics,
if desired. Shutdown Station at End
of Precrack
JIC Parameters
In the JIC Parameters section of the main menu, you select COD or Displacement as the control mode
for the test, and then specify the parameters for the selected mode.
COD Mode Parameters
Description Parameter
Specify the amount of force, in force units,
to unload in both the unload and reload
segments. JIC Absolute Unload
Specify the COD increment that will be
added to the current COD level at the JIC COD Increment
beginning of each ramp segment to
determine a maximum COD for this step. If
the maximum COD is reached before the
maximum displacement or load level is
reached, it triggers the next segment of the
step.
46 | MTS TestSuite
JIC Fracture Toughness Template