Fitting method

Normal stress

Experimental breaking stress/ Numerical breaking stress (MPa)

Percentage/ accuracy

Fourier

fourth order

0.1 MPa

0.895

0.56%

0.890

0.2 MPa

1.482

0.27%

1.478

0.3 MPa

2.001

0.10%

2.003

Exponential

0.1 MPa

0.895

1.90%

0.878

0.2 MPa

1.482

1.96%

1.453