Research Article

Damage Identification of a Derrick Steel Structure Based on the HHT Marginal Spectrum Amplitude Curvature Difference

Table 1

Damage condition of the derrick steel structure.

ConditionDamage degreeDamage typeDamage position

15%Single damage16
220%10
330%5
45%Double damage8, 14
510%5, 13
65%, 10%5, 13