A Damage Prognosis Method of Girder Structures Based on Wavelet Neural Networks
Table 6
Comparison of updated frequencies and measured frequencies (unit, Hz).
Vibration mode
Frequency (Hz)
Measured value-1 (SSI)
Updated value-1
Error-1 (%)
Measured value-2 (SSI)
Updated value-2
Error-2 (%)
Vertical
First order
2.89
2.88
0.43
2.87
2.77
3.48
Second order
3.03
3.081
1.84
3.16
2.89
8.66
Third order
3.79
3.61
0.51
3.67
3.34
8.99
Fourth order
4.26
4.32
1.27
4.25
4.02
5.37
Transverse
First order
0.83
0.73
0.16
0.92
0.87
4.90
Second order
1.43
1.47
2.84
1.45
1.48
1.45
Longitudinal
First order
1.79
1.74
2.45
1.30
1.28
1.61
Notice: measured value-1, updated value-1, and error-1 were the updated results in February 2012; measured value-2, updated value-2, and error-2 were the updated results in June 2013.
