Damage Detection Using Mode Shape Expansion and Finite Element Model Updating
Date Issued
2010
Date
2010
Author(s)
Wu, Yi-Cheng
Abstract
The purpose of this research is to employ the model updating technique to conduct the structural damage detection with insufficient measurements. In this study, a three stage damage detection algorithm is investigated. First, a mode shape expansion (MSE) technique is implemented to compensate the deficiency of insufficient measurements. Second, the model updating approach is introduced to correct the parameters of the FE model by using the measurement data. Third, a physical meaning damage index is adopted to locate and quantify damage simultaneously.
To investigate the effectiveness of the proposed MSE technique and model updating approaches, numerical studies with three types of sensor distributions and five damage scenarios were investigated. It can be seen that when the weighting coefficient of the proposed MSE technique is properly selected, the ability of reconstructing the mode shape is appreciated.
In cooperated with the MSE, five damage detection techniques based on the concept of model updating are investigated in this study: (1) Improved Damage Ritz Vector Method (IDRVM), (2) Minimum Rank Perturbation Theory (MRPT), (3) Modified Quadratic Compression Method (MQCM), (4) Efficient Model Correction Method (EMCM), and (5) Ratios of Stiffness to Mass Approach (RSMA). Numerical studies were investigated on all damage detection techniques. It can be observed that if the exact mode shapes can be reconstructed, then damage detection methods can performance well. Through these studies, EMCM has the best performance to damage detection by adopting the expanded mode shapes.
Data collected from the shaking table test of a six-story steel frame structure at National Center for Research on Earthquake Engineering in Taiwan (NCREE) were used to verify the applicability of the EMCM damage detection technique.
The study concludes that damage detection through mode shape expansion is possible if the expanded mode shapes are consistent with the exact mode shapes. Among all the damage detection methods, the Efficient Model Correction Method can provide good results of damage detection.
Subjects
insufficient measurement
mode shape expansion
system identification
model updating
damage detection
damage index
Type
thesis
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