What is the relationship between tauBase in the MCalibration BB model and the constant A in the ABAQUS implementation of the BB model? Looking at the math, the relationship seems to be:
A = tauBase^-m [s^-1 MPa^-m]
However, using data and the stated parameters from Dr. Bergstroms dissertation (Figure 5-11), I seem to have found the following relationship:
A = tauBase^m
For example, from Figure 5-11, C1hat = A = 0.6 [s^-1 MPa^-m]. Using the second relationship, I get tauBase = 0.88, which when used along with the rest of the parameters of Figure 5-11 and the data, gives me exactly the same predicted data. If I use the first relationship, I get tauBase = 1.136 abd the wrong curves in MCalibration.
What am I missing here? Thanks.