A New Approach for Free Vibration Analysis of Thin-Walled Box Girder Considering Shear Lag Effect

Table 2

Comparison of first four natural frequency parameters in different length-to-thickness ratios for square box beam.

Frequency order	L/a = 100		L/a = 10		L/a = 5
	R		R		R
1	0.0386	0.0396	0.3803	0.3894	14.5640	14.5692
2	0.0392	0.0401	0.3857	0.3979	14.7350	14.7381
3	2.7011	2.7034	27.0230	27.0285	54.1170	54.1186
4	4.3276	4.3292	43.1800	43.1837	85.9260	85.9273

Note. L/a: the length-to-thickness ratio of the beam; R: reference results; : present results.