Table 2 Fitting parameters of other formulas

Ramberg–Osgood

K/MPa

1375

1293

1361

763

1015

1011

m

0.0433

0.0482

0.0545

0.0642

0.1223

0.1234

Ludwigson

K₁/MPa

1550

1467

1534

832

1180

1260

m₁

0.079

0.085

0.090

0.0915

0.181

0.212

K₂

5.010

5.39

4.540

4.42

5.12

4.80

m₂

−202.4

−296.3

−584.7

−230

−155

−38.1

Ugent

σ_0.2/MPa

–

–

–

521

493

490

n₁

–

–

–

26.5

12.4

5.11

n₂

–

–

–

15.5

8.0

10.7

σ₁/MPa

–

–

–

536

535

490

σ₂/MPa

–

–

–

579

670

460

Gardner

n

–

–

–

15.1

16.5

4.43

E_0.2/10³ MPa

–

–

–

15.9

13.9

44.2

n ^′_0.2,1.0

–

–

–

1.55

2.20

3.05