scholarly journals A Novel VBSHM Strategy to Identify Geometrical Damage Properties Using Only Frequency Changes and Damage Library

2020 ◽  
Vol 10 (23) ◽  
pp. 8717
Author(s):  
Anurag Dubey ◽  
Vivien Denis ◽  
Roger Serra
Keyword(s):  
Frequency Shift ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Finite Element Models ◽  
Damage Localization ◽  
Shift Coefficient ◽  
Stiffness Reduction ◽  
New Strategy ◽  
Frequency Changes ◽  
2D And 3D

Vibration-based structural health monitoring is an efficient way to diagnose damage and structural integrity at the earliest stage. In this paper, a new strategy is developed for damage localization and estimation, as well as damage properties identification for a rectangular geometry damage using only eigenfrequencies of the healthy and damaged structure. This strategy is applied to a cantilever beam. In this framework, a damage library is built by correlating 2D and 3D finite element models. The correlation is done by minimizing a so-called frequency shift coefficient. The proposed strategy also uses the frequency shift coefficient to correlate a 2D damaged model with an unknown beam case. The 2D damage, represented by a bending stiffness reduction, is then associated to a 3D damage by employing the damage library. Numerical cases with single and double damage of varying position and severity are tested and used to validate the approach. Finally, experimental results are proposed that show the relevance of the strategy.

Damage Localization by Isolating the Part of the Response Due to the Damage Only

2012 ◽  
Vol 80 (1) ◽  
Author(s):  
Akash Dixit ◽  
Sathya Hanagud
Keyword(s):  
Finite Element ◽  
Linear System ◽  
Damage Detection ◽  
Physical Parameter ◽  
Health Monitoring ◽  
Natural Frequencies ◽  
Finite Element Models ◽  
Damage Localization ◽  
Partial Mode ◽  
Baseline State

A new physical parameter is presented and it is applied to damage detection to address the two main challenges in the field of vibration-based structural health monitoring: the sensitivity of detection and the requirement of data of the baseline state. The parameter is also shown to be not affected by noise in the detection ambience. Assuming the damaged structure to be a linear system, its response can be expressed as the summation of the responses due to the undamaged and the damaged part. If the part of the response due to the damage is isolated, it forms what can be regarded as the damage signature. In this paper, the occurrence of damage signature is investigated when the damaged structure is excited at one of its natural frequencies, and it is called partial-mode contribution. The existence of damage signature as partial-mode contribution is first verified using an analytical derivation. Thereupon, its existence is ascertained using finite element models and by doing experiments. The limits of size of the damage that can be determined using the method are also investigated.

scholarly journals Sensitivity and Efficiency of the Frequency Shift Coefficient Based on the Damage Identification Algorithm: Modeling Uncertainty on Natural Frequencies

Vibration ◽  
2022 ◽  
Vol 5 (1) ◽  
pp. 59-79
Author(s):  
Anurag Dubey ◽  
Vivien Denis ◽  
Roger Serra
Keyword(s):  
Frequency Shift ◽  
Health Monitoring ◽  
Natural Frequencies ◽  
Damage Identification ◽  
Input Parameter ◽  
Health Surveillance ◽  
Steel Beam ◽  
Identification Algorithm ◽  
Cantilever Beams ◽  
Shift Coefficient

Health surveillance in industries is an important prospect to ensure safety and prevent sudden collapses. Vibration Based Structure Health Monitoring (VBSHM) is being used continuously for structures and machine diagnostics in industry. Changes in natural frequencies are frequently used as an input parameter for VBSHM. In this paper, the Frequency Shift Coefficient (FSC) is used for the assessment of various numerical damaged cases. An FSC-based algorithm is employed in order to estimate the positions and severity of damages using only the natural frequencies of healthy and unknown (damaged) structures. The study focuses on cantilever beams. By considering the minimization of FSC, damage positions and severity are obtained. Artificially damaged cases are assessed by changes in its positions, the number of damages and the size of damages along with the various parts of the cantilever beam. The study is further investigated by considering the effect of uncertainty on natural frequencies (0.1%, 0.2% and 0.3%) in damaged cases, and the algorithm is used to estimate the position and severity of the damage. The outcomes and efficiency of the proposed FSC based method are evaluated in order to locate and quantify damages. The efficiency of the algorithm is demonstrated by locating and quantifying double damages in a real cantilever steel beam using vibration measurements.

scholarly journals A Novel Composite with Structural Health Monitoring Functionality via 2D and 3D Impedance Mapping Topography

2021 ◽  
Vol 11 (4) ◽  
pp. 1647
Author(s):  
Georgios Foteinidis ◽  
Alkiviadis S. Paipetis
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Integrity ◽  
Carbon Fabric ◽  
Structural Health ◽  
The Matrix ◽  
Junction Points ◽  
Sinusoidal Electric Field ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We report the transformation of a conventional composite material into a multifunctional structure able to provide information about its structural integrity. A purposely positioned grid of carbon fabric strips located within a glass fibre laminate in alternating 0/90 configuration combined with a ternary nanomodified epoxy matrix imparted structural health monitoring (SHM) topographic capabilities to the composite using the impedance spectroscopy (IS) technique. The matrix was reinforced with homogenously dispersed multi-walled carbon nanotubes (MWCNTs) and carbon black (CB). A sinusoidal electric field was applied locally over a frequency range from 1 Hz to 100 kHz between the junction points of the grid of carbon fabric strips. The proposed design enabled topographic damage assessment after a high-velocity impact via the local monitoring of the impedance. The data obtained from the IS measurements were depicted by magnitude and phase delay Bode plots and Nyquist plots. The impedance values were used to create a 2D and a multi-layer (3D) contour topographical image of the damaged area, which revealed crucial information about the structural integrity of the composite.

scholarly journals Sensor Networks for Structures Health Monitoring: Placement, Implementations, and Challenges—A Review

Vibration ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 551-584
Author(s):  
Samir Mustapha ◽  
Ye Lu ◽  
Ching-Tai Ng ◽  
Pawel Malinowski
Keyword(s):  
Sensor Networks ◽  
Health Monitoring ◽  
Data Transmission ◽  
System Integration ◽  
Structural Integrity ◽  
Low Cost ◽  
Data Communication ◽  
Total Cost ◽  
Design And Optimization ◽  
Successful Case

The development of structural health monitoring (SHM) systems and their integration in actual structures has become a necessity as it can provide a robust and low-cost solution for monitoring the structural integrity of and the ability to predict the remaining life of structures. In this review, we aim at focusing on one of the important issues of SHM, the design, and implementation of sensor networks. Location and number of sensors, in any SHM system, are of high importance as they impact the system integration, system performance, and accuracy of assessment, as well as the total cost. Hence we are interested in shedding the light on the sensor networks as an essential component of SHM systems. The review discusses several important parameters including design and optimization of sensor networks, development of academic and commercial solutions, powering of sensors, data communication, data transmission, and analytics. Finally, we presented some successful case studies including the challenges and limitations associated with the sensor networks.

An Optimal Sensitivity-Enhancing Feedback Control Approach via Eigenstructure Assignment for Structural Damage Identification

2007 ◽  
Vol 129 (6) ◽  
pp. 771-783 ◽  
Author(s):  
L. J. Jiang ◽  
J. Tang ◽  
K. W. Wang
Keyword(s):  
Feedback Control ◽  
Frequency Shift ◽  
Natural Frequency ◽  
Structural Damage ◽  
Closed Loop ◽  
Damage Identification ◽  
Frequency Measurement ◽  
Sensitivity Enhancement ◽  
Stiffness Reduction ◽  
Structural Damage Identification

The concept of using sensitivity-enhancing feedback control to improve the performance of frequency-shift-based structural damage identification has been recently explored. In previous studies, however, the feedback controller is designed to alter only the closed-loop eigenvalues, and the effect of closed-loop eigenvectors on the sensitivity enhancement performance has not been considered. In this research, it is shown that the sensitivity of the natural frequency shift to the damage in a multi-degree-of-freedom structure can be significantly influenced by the placement of both the eigenvalues and the eigenvectors. A constrained optimization problem is formulated to find the optimal assignment of both the closed-loop eigenvalues and eigenvectors, and then an optimal sensitivity-enhancing control is designed to achieve the desired closed-loop eigenstructure. Another advantage of this scheme is that the dataset of frequency measurement for damage identification can be enlarged by utilizing a series of closed-loop controls, which can be realized by activating different combinations of actuators in the system. Therefore, by using this proposed idea of multiple sensitivity-enhancing feedback controls, we can simultaneously address the two major limitations of frequency-shift-based damage identification: the low sensitivity of frequency shift to damage effects and the deficiency of frequency measurement data. A series of case studies are performed. It is demonstrated that the sensitivity of natural frequency shift to stiffness reduction can be significantly enhanced by using the designed sensitivity-enhancing feedback control, where the optimal placement of closed-loop eigenvectors plays a very important role. It is further verified that such sensitivity enhancement can directly benefit the damage identification accuracy and robustness.

scholarly journals Diseño e implementación de un sistema de adquisición y monitoreo de datos (shm) para un rectificador de protección catódica usado en ductos.

Respuestas ◽  
2016 ◽  
Vol 21 (1) ◽  
pp. 45 ◽  
Author(s):  
Daniel Alejandro Rodríguez-Caro ◽  
Enrique Vera-López ◽  
Helver Mauricio Muñoz-Barajas
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Cathodic Protection ◽  
Structural Integrity ◽  
Protection System ◽  
Performance Criteria ◽  
Correct Operation ◽  
Structural Health ◽  
El Sistema ◽  
Cathodic Protection System

Antecedentes: La protección catódica por corriente impresa es uno de los métodos para prevenir la corrosión de tuberías o tanques, preservando el estado estructural y la integridad del material. Para que un sistema de protección catódica funcione correctamente debe existir un control sobre las variables eléctricas que intervienen en el proceso, es por ello que se hace necesario monitorear variables tales como (Voltaje, Corriente y Potencial de protección). Objetivo: De esta manera se desarrolla un sistema de adquisición y monitoreo de datos en tiempo real, con el propósito de aumentar la accesibilidad a las variables eléctricas y de esta forma mejorar el funcionamiento del sistema de protección catódica. Métodos: El sistema de monitoreo y análisis de la información se basa en el concepto de SHM (Structural Health Monitoring), el cual consta de; un sistema electrónico de adquisición y envío remoto de señales (micro controlador y sistema GSM de comunicaciones) y un sistema de visualización y análisis de la información en un sistema móvil (celular), usando un servidor web para ello. Teniendo en cuenta que la condición de integridad estructural del ducto está determinada por el correcto funcionamiento del rectificador. Resultados: se logró implementar un sistema de monitoreo y visualización remota de las variables principales de un sistema de protección catódica. Se desarrolló un algoritmo basado en el concepto de SHM, el cual permite correlacionar, generar tendencia y establecer criterios de funcionamiento del sistema de protección catódica que permiten establecer si el sistema está asegurando la integridad estructural del ducto de transporte de crudo. Conclusión: lo novedoso del presente trabajo consiste en mostrar el comportamiento en tiempo real de las variables necesarias para analizar si el ducto está siendo correctamente protegido y generar las alarmas e informes sobre protección catódica, lo cual es la base del concepto de SHM (Structural Health Monitoring).AbstractBackground: Cathodic protection by impressed current is one of the methods to prevent corrosion of pipes or tanks, preserving the structural state and integrity of the material. For a cathodic protection system to function properly there must to be a control over the electrical variables involved in the process, which is why it is necessary to monitor variables such as (voltage, current and potential protection). Objective: to develop a system of data acquisition and monitoring in real time, in order to increase accessibility to electrical variables and thus improve the operation of the cathodic protection system. Methods: The monitoring and information analysis system is based on the concept of SHM (Structural Health Monitoring), which consists of an electronic system for remote acquisition and sending of signals (micro controller and GSM communications system) and a system for visualization and analysis of information in a mobile system (cell) using a web server for it. Given that the condition of structural integrity of the pipeline is determined by the correct operation of the rectifier. Results: It was possible to implement a monitoring and remote viewing system of the main variables of a cathodic protection system. An algorithm based on the concept of SHM was developed, allowing to correlate, generate trend and establish performance criteria for the cathodic protection system which allows to establish whether the system is ensuring the structural integrity of the crude transportation pipeline. Conclusion: the novelty of this work is to show the realtime behavior of the variables needed to analyze whether the pipeline is being properly protected and generate alarms and reports regarding cathodic protection, which is based on the concept of SHM (Structural Health Monitoring).Palabras Clave: corriente, corrosión, Innovación, monitoreo, SHM (Structural Health Monitoring)

Adaptive sparse reconstruction of damage localization via Lamb waves for structure health monitoring

Computing ◽  
2019 ◽  
Vol 101 (6) ◽  
pp. 679-692 ◽  
Author(s):  
Hanfei Zhang ◽  
Yu Lu ◽  
Shiwei Ma ◽  
Shuhao Cao ◽  
Qingwei Xia ◽  
...  
Keyword(s):  
Health Monitoring ◽  
Lamb Waves ◽  
Sparse Reconstruction ◽  
Damage Localization ◽  
Structure Health Monitoring

scholarly journals GIS and BIM as Integrated Digital Environments for Modeling and Monitoring of Historic Buildings

2020 ◽  
Vol 10 (3) ◽  
pp. 1078 ◽  
Author(s):  
Elisavet Tsilimantou ◽  
Ekaterini T. Delegou ◽  
Ioannis A. Nikitakos ◽  
Charalabos Ioannidis ◽  
Antonia Moropoulou
Keyword(s):  
Information System ◽  
Structural Integrity ◽  
Information Modeling ◽  
Historic Building ◽  
Multidisciplinary Data ◽  
Building Information ◽  
Digital Environments ◽  
Quantitative Manner ◽  
3D Information ◽  
2D And 3D

Multidisciplinary data integration within an information system is considered a key point for rehabilitation projects. Information regarding the state of preservation and/or decision making, for sustainable restoration is prerequisite. In addition, achieving structural integrity of a historic building, especially one that has undergone many construction phases and restoration interventions, is a very elaborate task and should, therefore, involve the study of multidisciplinary information regarding historical, architectural, building material and geometric data. In this paper the elaboration of such data within 2D and 3D information systems is described. Through the process described herein, a methodology, including the acquisition, classification and management of various multisensory data, is displayed and applied within a geographic information system (GIS). Moreover, the multidisciplinary documentation process, aggregated with the surveying products, generates 3D heritage building information modeling (HBIM), including information regarding construction phases, pathology and current state of preservation of a building. The assessment of the applied methodology is performed concluding in a qualitative and a quantitative manner, in both 2D and 3D environments, providing information to facilitate the structural assessment of a historic building. Thus, in this work, the described methodology is presented, combining the multidisciplinary data with the development of GIS thematic maps and an HBIM. Representative results of the suggested methodology applied on the historic building of Villa Klonaridi, Athens, Greece are displayed.

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