A Multi-State Strategy for Structural Damage Detection Using Sensitivity of Weighted Transmissibility Function

In practice, a model-based structural damage detection (SDD) method is helpful for locating and quantifying damages with the aid of reasonable finite element (FE) model. However, only limited information in single or two structural states is often used for model updating in existing studies, which is not reasonable enough to represent real structures. Meanwhile, as an output-only damage indicator, transmissibility function (TF) is proven to be effective for SDD, but it is not sensitive enough to change in structural parameters. Therefore, a multi-state strategy based on weighted TF (WTF) is proposed to improve sensitivity of TF to change in parameters and in order to further obtain a more reasonable FE model for SDD in this study. First, WTF is defined by TF weighted with element stiffness matrix, and relationships between WTFs and change in structural parameters are established based on sensitivity analysis. Then, a multi-state strategy is proposed to obtain multiple structural states, which is used to reasonably update the FE model and detect structural damages. Meanwhile, due to fabrication errors, a two-stage scheme is adopted to reduce the global and local discrepancy between the real structure and the FE model. Further, the [Formula: see text]-norm and the [Formula: see text]-norm regularization techniques are, respectively, introduced for both model updating and SDD problems by considering the characteristics of problems. Finally, the effectiveness of the proposed method is verified by a simply supported beam in numerical simulations and a six-storey frame in laboratory. From the simulation results, it can be seen that the sensitivity to structural damages can be improved by the definition of WTF. For the experimental studies, compared with the FE model updated from the single structural state, the FE model obtained by the multi-state strategy has an ability to more reasonably describe the change of states in the frame. Moreover, for the given structural damages, the proposed method can detect damage locations and degrees accurately, which shows the validity of the proposed method and the reliability of the updated FE model.

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A DE-Based Algorithm for Structural Damage Detection

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.919-921.303 ◽

2014 ◽

Vol 919-921 ◽

pp. 303-307 ◽

Cited By ~ 1

Author(s):

Yong Ming Fu ◽

Ling Yu

Keyword(s):

Damage Detection ◽

Objective Function ◽

Structural Damage ◽

Model Updating ◽

Heuristic Method ◽

Identification Accuracy ◽

Frame Structure ◽

Mode Shapes ◽

Fe Model ◽

Structural Damage Detection

The development of a methodology for the accurate and reliable assessment of structural damages, as one crucial step in the structural health monitoring (SHM) field, is very important to ensure the safety, integrity and stability of structures. An improved adaptive differential evolution (IADE) algorithm is proposed for structural damage detection (SDD) based on DE algorithm and FE model-updating techniques. An objective function is defined as minimizing the discrepancies between the experimental and analytical modal parameters (namely, natural frequencies and mode shapes). It is set as a nonlinear least-squares problem with bound constraints. Unlike the commonly used line-search methods, the IADE approach, a heuristic method for the direct search of the optimal point of the given objective function, is employed to make the optimization process more robust and reliable. Some numerical simulations for single and multiple damage cases of a 25-bar space truss frame structure have been conducted for evaluation on the reliability and robustness of the proposed method. The illustrated results show that the IADE algorithm is very effective for SDD. It can not only locate the structural damages but also quantify the severity of damages. Regardless of slight damage or multiple damages, the identification accuracy is very high and noise immunity is better, which shows that the IADE algorithm is feasible and effective for SDD.

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Structural Damage Assessment Using Output-Only Measurement: Localization and Quantification

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting ◽

10.1115/smasis2013-3008 ◽

2013 ◽

Author(s):

Chin-Hsiung Loh ◽

Min-Hsuan Tseng ◽

Shu-Hsien Chao

Keyword(s):

Damage Detection ◽

Damage Assessment ◽

Structural Damage ◽

Damage Identification ◽

Model Updating ◽

Null Space ◽

Singular Spectrum Analysis ◽

Damage Index ◽

Computation Efficiency ◽

Output Only

One of the important issues to conduct the damage detection of a structure using vibration-based damage detection (VBDD) is not only to detect the damage but also to locate and quantify the damage. In this paper a systematic way of damage assessment, including identification of damage location and damage quantification, is proposed by using output-only measurement. Four level of damage identification algorithms are proposed. First, to identify the damage occurrence, null-space and subspace damage index are used. The eigenvalue difference ratio is also discussed for detecting the damage. Second, to locate the damage, the change of mode shape slope ratio and the prediction error from response using singular spectrum analysis are used. Finally, to quantify the damage the RSSI-COV algorithm is used to identify the change of dynamic characteristics together with the model updating technique, the loss of stiffness can be identified. Experimental data collected from the bridge foundation scouring in hydraulic lab was used to demonstrate the applicability of the proposed methods. The computation efficiency of each method is also discussed so as to accommodate the online damage detection.

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VIBRATION-BASED STRUCTURAL DAMAGE DETECTION UNDER VARYING TEMPERATURE CONDITIONS

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455412500824 ◽

2013 ◽

Vol 13 (05) ◽

pp. 1250082 ◽

Cited By ~ 3

Author(s):

XIAO-QING ZHOU ◽

WEN HUANG

Keyword(s):

Damage Detection ◽

Structural Damage ◽

Natural Frequencies ◽

Environmental Changes ◽

Model Updating ◽

Modal Testing ◽

Structural Damage Detection ◽

Vibration Data ◽

Temperature Conditions ◽

Vibration Properties

In vibration-based structural damage detection, it is necessary to discriminate the variation of structural properties due to environmental changes from those caused by structural damages. The present paper aims to investigate the temperature effect on vibration-based structural damage detection in which the vibration data are measured under varying temperature conditions. A simply-supported slab was tested in laboratory to extract the vibration properties with modal testing. The slab was then damaged and the modal testing was conducted again, in which the temperature varied. The modal data measured under different temperature conditions were used to detect the damage with a two-stage model updating technique. Some damage was falsely detected if the temperature variation was not considered. Natural frequencies were then corrected to those under the same temperature conditions according to the relation between the temperature and material modulus. It is shown that all of the damaged elements can be accurately identified.

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