The generalized flexibility matrix method for structural damage detection with incomplete mode shape data

2021 ◽  
pp. 1-21
Author(s):  
Haifeng Liu ◽  
Baisheng Wu ◽  
Zhengguang Li
Keyword(s):  
Damage Detection ◽  
Mode Shape ◽  
Matrix Method ◽  
Structural Damage ◽  
Structural Damage Detection ◽  
Flexibility Matrix ◽  
Shape Data

A Coupled Sensitivity Method for Structural Damage Detection

2013 ◽  
Vol 681 ◽  
pp. 271-275
Author(s):  
Jing Li ◽  
Pei Jun Wei
Keyword(s):  
Damage Detection ◽  
Mode Shape ◽  
Structural Damage ◽  
Damage Identification ◽  
Perturbation Approach ◽  
Structural Damage Detection ◽  
Beam Structure ◽  
Flexibility Matrix ◽  
Eigenvalue Sensitivity ◽  
Sensitivity Method

Based on the vibration information, a mixed sensitivity method is presented to identify structural damage by combining the eigenvalue sensitivity with the generalized flexibility sensitivity. The sensitivity of structural generalized flexibility matrix is firstly derived by using the first frequency and the corresponding mode shape only and then the eigenvalue sensitivity together with the generalized flexibility sensitivity are combined to calculate the elemental damage parameters. The presented mixed perturbation approach is demonstrated by a numerical example concerning a simple supported beam structure. It has been shown that the proposed procedure is simple to implement and may be useful for structural damage identification.

Structural Damage Detection Based on Generalized Flexibility Matrix

2012 ◽  
Vol 594-597 ◽  
pp. 1074-1077 ◽  
Author(s):  
Jing Li
Keyword(s):  
Damage Detection ◽  
Mode Shape ◽  
Structural Damage ◽  
Structural Damage Detection ◽  
Numerical Example ◽  
Flexibility Matrix ◽  
The Difference

Based on the generalized flexibility matrix, a method for detecting structural damage is presented in this paper. The generalized flexibility matrix is approximately constructed by using the first frequency and the corresponding mode shape only. Then the difference of generalized flexibility curvature between undamaged and damaged state is used to detect the possible damaged elements. Finally, a numerical example concerning a simple supported beam is used to illustrate the effectiveness of the proposed method.

scholarly journals Structural Damage Detection by Using Single Natural Frequency and the Corresponding Mode Shape

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Zhao ◽  
Zili Xu ◽  
Xuanen Kan ◽  
Jize Zhong ◽  
Tian Guo
Keyword(s):  
Damage Detection ◽  
Natural Frequency ◽  
Mode Shape ◽  
Structural Damage ◽  
Bending Moment ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Structural Damage Detection ◽  
Damage Scenarios ◽  
Flexibility Matrix

Damage can be identified using generalized flexibility matrix based methods, by using the first natural frequency and the corresponding mode shape. However, the first mode is not always appropriate to be used in damage detection. The contact interface of rod-fastened-rotor may be partially separated under bending moment which decreases the flexural stiffness of the rotor. The bending moment on the interface varies as rotating speed changes, so that the first- and second-modal parameters obtained are corresponding to different damage scenarios. In this paper, a structural damage detection method requiring single nonfirst mode is proposed. Firstly, the system is updated via restricting the first few mode shapes. The mass matrix, stiffness matrix, and modal parameters of the updated system are derived. Then, the generalized flexibility matrix of the updated system is obtained, and its changes and sensitivity to damage are derived. The changes and sensitivity are used to calculate the location and severity of damage. Finally, this method is tested through numerical means on a cantilever beam and a rod-fastened-rotor with different damage scenarios when only the second mode is available. The results indicate that the proposed method can effectively identify single, double, and multiple damage using single nonfirst mode.

scholarly journals Damaged Flexibility Matrix Method for Damage Detection of Frame Buildings

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Luis S. Vaca Oyola ◽  
Mónica R. Jaime Fonseca ◽  
Ramsés Rodríguez Rocha
Keyword(s):  
Damage Detection ◽  
Matrix Method ◽  
Structural Damage ◽  
Numerical Models ◽  
Structural Elements ◽  
Structural Element ◽  
New Approach ◽  
Building Model ◽  
Flexibility Matrix ◽  
Frame Buildings

This study presents the damaged flexibility matrix method (DFM) to identify and determine the magnitude of damage in structural elements of plane frame buildings. Damage is expressed as the increment in flexibility along the damaged structural element. This method uses a new approach to assemble the flexibility matrix of the structure through an iterative process, and it adjusts the eigenvalues of the damaged flexibility matrices of each system element. The DFM was calibrated using numerical models of plane frames of buildings studied by other authors. The advantage of the DFM, with respect to other flexibility-based methods, is that DFM minimizes the adverse effect of modal truncation. The DFM demonstrated excellent accuracy with complete modal information, even when it was applied to a more realistic scenario, considering frequencies and modal shapes measured from the recorded accelerations of buildings stories. The DFM also presents a new approach to simulate the effects of noise by perturbing matrices of flexibilities. This approach can be useful for research on realistic damage detection. The combined effects of incomplete modal information and noise were studied in a ten-story four-bay building model taken from the literature. The ability of the DFM to assess structural damage was corroborated. Application of the proposed method to a ten-story four-bay building model demonstrates its efficiency to identify the flexibility increment in damaged structural elements.

scholarly journals A Universal Fast Algorithm for Sensitivity-Based Structural Damage Detection

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Q. W. Yang ◽  
J. K. Liu ◽  
C.H. Li ◽  
C.F. Liang
Keyword(s):  
Damage Detection ◽  
Fast Algorithm ◽  
Structural Damage ◽  
Research Area ◽  
Detection Methods ◽  
Structural Damage Detection ◽  
Response Data ◽  
Flexibility Matrix ◽  
New Research ◽  
Measured Response

Structural damage detection using measured response data has emerged as a new research area in civil, mechanical, and aerospace engineering communities in recent years. In this paper, a universal fast algorithm is presented for sensitivity-based structural damage detection, which can quickly improve the calculation accuracy of the existing sensitivity-based technique without any high-order sensitivity analysis or multi-iterations. The key formula of the universal fast algorithm is derived from the stiffness and flexibility matrix spectral decomposition theory. With the introduction of the key formula, the proposed method is able to quickly achieve more accurate results than that obtained by the original sensitivity-based methods, regardless of whether the damage is small or large. Three examples are used to demonstrate the feasibility and superiority of the proposed method. It has been shown that the universal fast algorithm is simple to implement and quickly gains higher accuracy over the existing sensitivity-based damage detection methods.

Structural Damage Detection Using Generalized Flexibility Matrix and Changes in Natural Frequencies

AIAA Journal ◽  
2012 ◽  
Vol 50 (5) ◽  
pp. 1072-1078 ◽  
Author(s):  
Jing Li ◽  
Zhengguang Li ◽  
Huixiang Zhong ◽  
Baisheng Wu
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Natural Frequencies ◽  
Structural Damage Detection ◽  
Flexibility Matrix

scholarly journals Multiple Damage Detection of an Offshore Helideck through the Two-Step Artificial Neural Network Based on the Limited Mode Shape Data

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7357
Author(s):  
Byungmo Kim ◽  
Chanyeong Kim ◽  
Seung-Hyun Ha
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Damage Detection ◽  
Mode Shape ◽  
Structural Damage ◽  
Mode Shapes ◽  
Estimation Accuracy ◽  
The Neural Network ◽  
Artificial Neural ◽  
Shape Data

A helideck is an essential structure in an offshore platform, and it is crucial to maintain its structural integrity and detect the occurrence of damage early. Because helidecks usually consist of complex lattice truss members, precise measurements are required for structural health monitoring based on accurate modal parameters. However, available sensors and data acquisition are limited. Therefore, we propose a two-step damage detection process using an artificial neural network. Based on the mode shape database collected from 137,400 damage scenarios by finite element analysis, the neural network in the first step was trained to estimate the mode shapes of the entire helideck model using the selected mode shape data obtained from the limited measuring points. Then, the neural network in the second step is consecutively trained to detect the location and amount of structural damage to individual parts. As a result, it is shown that the proposed procedure provides the damage detection capability with only a quarter of the entire mode shape data, while the estimation accuracy is sufficiently high compared to the single network directly trained using all mode shape data. It was also found that, compared to the network directly trained from the same data, the proposed technique tends to detect minor damages more accurately.

Sign in / Sign up

Export Citation Format

Share Document