Introduction
If you perform uniaxial tension or compression experiments, then it is useful to also record the transverse strain during the test. This article shows how you can use this data to calibrate a suitable material model.
Step 1: Experimental Data
First make sure your experimental data file contains both the standard columns [time, strain, stress], and a column for the transverse strain. Here is an example:
% column 1: Time [s]
% column 2: Engineering Strain
% column 3: Engineering Stress [MPa]
% column 4: Transverse Strain
0, 0, 0, 0
0.010038001, 0.00021036632, 0.4261087, -3.1511109e-05
0.020076003, 0.00042073265, 0.85221743, -6.3022219e-05
0.030114004, 0.00063109897, 1.2784391, -9.4533328e-05
0.040045722, 0.00083428696, 1.704824, -0.00012367787
0.049930192, 0.0010342838, 2.1313721, -0.00015177036
0.059814662, 0.0012342807, 2.5579185, -0.00017986286
. . .
Step 2: Set Load Case in MCalibration
Read in the experimental data file into MCalibration, and make sure you assign fitness weight factor for the transverse strain. The value of this factor tells MCalibration how important the transverse strain is for the calibration.
Step 3. Set Material Model
Make sure the bulk modulus parameters are selected to be optimized. For the PolyUMod TNV model, also make sure you select the volumetric flow parameter bb to be searched for. Finally, just run the material model calibration!
