Refined Vehicle-Bridge Interaction Analysis Using Incompatible Solid Finite Element for Evaluating Stresses and Impact Factors

Table 4

Modal parameters of the solid (grillage) bridge FE model before and after updating.

Modes	Frequency (Hz)			Frequency error (%)		MAC values (%)
	Initial	Updated	Measured	Initial	Updated	Initial	Updated
1^st vertical bending	4.61 (4.53)	4.86 (4.71)	4.81	4.29 (5.82)	−1.04 (2.08)	99.9 (99.9)	99.9 (99.9)
1^st torsion	6.77 (6.71)	7.08 (6.89)	7.14	5.23 (6.05)	0.84 (3.45)	96.5 (86.5)	98.9 (90.5)
2^nd vertical bending	14.89 (14.93)	15.77 (15.65)	16.03	7.09 (6.84)	1.61 (2.37)	89.4 (82.3)	92.3 (89.6)