Civil Engineering Reference
In-Depth Information
Mode
Frequency
[Hz]
Std. dev. Frequency
[Hz]
Damping
[%]
Std. dev. Damping
[%]
B1
1.193
0.0073
1.89
0.14
B2
2.734
0.0029
0.63
0.062
B3
3.044
0.0083
0.88
0.13
B4
4.06
0.0053
0.74
0.20
B5
5.029
0.0065
0.58
0.079
B6
5.635
0.010
0.41
0.028
B7
9.433
0.035
0.53
0.18
B8
9.991
0.016
0.49
0.051
B9
10.72
0.015
0.74
0.10
Fig. 2.14
Nine bridge natural modes could be identified in the range f
¼
1.19
...
10.7 Hz. Damping of mode B1 and, to a lesser extent, of mode B3,
is comparatively large. This is most probably due to the pylon modal motion being relatively large for these modes (see Chap.
7
)
Fig. 2.15
(
a
) Mode 1, f
¼
1.19 Hz,
ζ ¼
1.9 %. (
b
) Mode 2, f
¼
2.73 Hz,
ζ ¼
0.6 %. (
c
) Mode 3, f
¼
3.04 Hz,
ζ ¼
0.9 %. (
d
) Mode 4,
f
¼
4.06 Hz,
ζ ¼
0.7 %. (
e
) Mode 5, f
¼
5.03 Hz,
ζ ¼
0.6 %. (
f
) Mode 6, f
¼
5.64 Hz,
ζ ¼
0.4 %. (
g
) Mode 7, f
¼
9.43 Hz,
ζ ¼
0.5 %. (
h
) Mode
8, f
¼
9.99 Hz,
ζ ¼
0.5 %
