Response Surface-Based Finite Element Model Updating of Steel Box-Girder Bridges with Concrete Composite Decks

Table 1

Bridge mode from FEM in comparison with measured results.

Modal order	FEM (Hz)	Mode shape	Measured frequency (Hz)	Difference (%)
1	3.77	First-order asymmetric vertical bending	4.00	−5.75
2	4.99	First-order symmetric vertical bending	5.03	−0.79
3	5.30	First-order symmetric torsion	5.27	+0.57
4	7.47	First-order asymmetric torsion	7.23	+3.32
5	11.96	Second-order symmetric torsion	10.99	+8.83
6	14.95	Second-order asymmetric torsion	14.01	+6.71