Research on Vibration Fatigue Damage Locations of Offshore Oil and Gas Pipelines Based on the GA-Improved BP Neural Network

Table 2

Measured natural frequencies of the pipeline model (Hz).

Modal order number	Model number
	No. 1	No. 2	No. 3	No. 4
1	11.694	11.719	11.209	10.668
2	14.089	14.063	13.281	14.063
3	20.411	20.313	20.099	19.531
4	29.892	29.521	27.368	29.363
5	36.045	35.938	31.269	35.938
6	39.111	38.281	36.169	37.632
7	40.715	40.625	40.625	40.625
8	61.765	61.719	61.417	60.536
9	72.592	71.809	71.012	72.026
10	90.633	90.493	90.510	90.308