Strain modal-based damage identification method and its application to crane girder without original model

Abstract

Although there are many methods to identify structural damage of the crane girder, almost all of them are used by means of comparing specific parameters of original and existing structures. And it leads to difficulties in practice. So, a method to identify damage of the crane girder is proposed based on strain modal without original model. First, the strain modal difference curve was obtained by using difference algorithm to deal with strain modal and cubic spline interpolation algorithm to fit the curve, and the damage location was realized by constructing and comparing damage sensitive index (IDSI). Then, the data of undamaged checkpoints adjacent to damaged checkpoints are stationary and modeled by Auto-Regressive Moving-Average Model, with this modeling the original data of the damaged checkpoints was predicted, and variation of the got strain modal difference curve was used to determine damage degree. Finally, the application of this method was implemented by some experiments and numerical calculations, and the results demonstrated that this method can effectively identify the damage of the crane girder.

Damage identification of structures based on sensitivity equations using PCA and PSD data

“…Janeliukstis et al 10 and Wang et al 11 employed mode shape curvature for crack and damage detection in prestressed concrete railway sleepers and wind turbine blades, respectively. Jayasundara et al 12 and Yang et al 13 used modal strain energy to experimentally identify damage to bridge and beam structures, respectively. Abdel-Basset 14 used changes in the measured static response to locate structural damage in an overhanging beam and a two-span continuous beam.…”

“…One issue in model updating is the choice of matrices. These include structural responses such as natural frequency, 3,4 mode shape, 5,6 frequency response function (FRF), 7,8 modal flexibility, 9 mode shape curvature, 10,11 modal strain, modal strain energy, 12,13 static responses, 14 and other dynamic responses. 15 Jiang et al 3 used singular value decomposition (SVD) to reveal singularities in modal shapes and localize structural damage.…”