Experimental and Numerical Investigation of the Effect of Standing People on Dynamic Properties of a Beam-Like Bridge

Table 3

First vertical bending frequency and modal damping ratio of the bridge.

Number of occupants	Mass ratio (occupants/bridge)	Equivalent mass	Stand with straight knees		Stand with bent knees
		Frequency (Hz)	Frequency (Hz)	Modal damping ratio (%)	Frequency (Hz)	Modal damping ratio (%)
0	0	2.82	2.83	0.42	2.83	0.42
1	0.025	2.73	2.73	0.94	2.73	2.20
3	0.071	2.62	2.60	1.05	2.63	5.61
5	0.110	2.54	2.57	1.23	2.59	7.55
7	0.155	2.48	2.48	1.43	2.50	8.16
9	0.182	2.46	2.42	1.42	2.47	8.38
13	0.255	2.43	2.41	1.45	2.44	9.19
15	0.291	2.42	2.40	1.44	2.42	9.57

Note. The results of equivalent mass model were obtained using the FE model attached with equivalent mass.