${T^{″}}_{\text{d0}}$ (s)

0.020

0.023

0.026

0.029

0.032

0.035

Frequency (Hz)

1.262

1.203

1.251

1.166

1.219

1.174

Damping ratio (%)

25.667

24.390

26.483

22.538

28.185

30.647

${T^{″}}_{\text{d0}}$ (s)

0.038

0.041

0.044

0.047

0.050

Frequency (Hz)

1.194

1.184

1.186

1.189

1.192

Damping ratio (%)

31.080

18.083

17.250

16.728

16.095