${T^{″}}_{\text{d0}}$ (s)

0.020

0.023

0.026

0.029

0.032

0.035

Frequency (Hz)

1.3023

1.3025

1.3028

1.3030

1.3032

1.3032

Damping ratio (%)

6.30

6.20

6.10

6.01

5.89

5.83

${T^{″}}_{\text{d0}}$ (s)

0.038

0.041

0.044

0.047

0.050

Frequency (Hz)

1.3033

1.3034

1.3034

1.3034

1.3033

Damping ratio (%)

5.74

5.65

5.57

5.49

5.41