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Article
Publication date: 5 June 2007

Gao Zhan‐feng, Du Yan‐liang, Sun Bao‐chen and Jin Xiu‐mei

The purpose of this article is to suggest that Fraby‐Perot optic sensor is a practical measurement gage to monitor the strain of great structures such as railway bridges.

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Abstract

Purpose

The purpose of this article is to suggest that Fraby‐Perot optic sensor is a practical measurement gage to monitor the strain of great structures such as railway bridges.

Design/methodology/approach

A remote strain monitoring system based on F‐P optic fiber and virtual instrument is designed to monitor the strains of a railway bridge.

Findings

The application results show that the Fraby‐Perot optical fiber sensors can accurately measure strain and they are suitable for the long‐term and automatic monitoring. In addition, the system has several advantages over conventional structural instruments including fast response, ability of both static and dynamic monitoring, absolute measurement, immunity to interferences such as lightning strikes, electromagnetic noise and radio frequency, low attenuation of light signals in long fiber optic cables.

Practical implications

Health monitoring of structures is getting more and more recognition all over the world because it can minimize the cost of reparation and maintenance and ensure the safety of structures. A strain monitoring system based on F‐P optic fiber sensor was developed according to the health monitoring requirements of Wuhu Yangtze River Railway Bridge, which is the first cable‐stayed bridge with a maximum span of 312 m carrying both railway and highway traffic in China. It has run stably in the monitoring field more than two years and fulfilled the monitoring requirement very well. Now the system has been transplanted successfully to the Zhengzhou Yellow Railway Bridge for strain monitoring. So the work can be referenced by other similar health monitoring projects.

Originality/value

Long‐term, real‐time monitoring of strain using FP fiber optic sensors in railway bridge is an innovation. A remote strain data acquisition and real‐time processing are another character of the system. The work studied can be referenced by other structures monitoring, such as tunnel, concrete bridges, concrete and earth dams.

Details

Journal of Quality in Maintenance Engineering, vol. 13 no. 2
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 28 June 2011

Bengi Aygün and Vehbi Cagri Gungor

The purpose of this paper is to provide a contemporary look at the current state‐of‐the‐art in wireless sensor networks (WSNs) for structure health monitoring (SHM…

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1821

Abstract

Purpose

The purpose of this paper is to provide a contemporary look at the current state‐of‐the‐art in wireless sensor networks (WSNs) for structure health monitoring (SHM) applications and discuss the still‐open research issues in this field and, hence, to make the decision‐making process more effective and direct.

Design/methodology/approach

This paper presents a comprehensive review of WSNs for SHM. It also introduces research challenges, opportunities, existing and potential applications. Network architecture and the state‐of‐the‐art wireless sensor communication technologies and standards are explained. Hardware and software of the existing systems are also clarified.

Findings

Existing applications and systems are presented along with their advantages and disadvantages. A comparison landscape and open research issues are also presented.

Originality/value

The paper presents a comprehensive and recent review of WSN systems for SHM applications along with open research issues.

Details

Sensor Review, vol. 31 no. 3
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 29 April 2014

Igor Pavelko, Vitalijs Pavelko, Sergey Kuznetsov and Ilmars Ozolinsh

The purpose of this paper is to present the problems of the electromechanical impedance (EMI), especially its applications for structural health monitoring of aircraft…

Abstract

Purpose

The purpose of this paper is to present the problems of the electromechanical impedance (EMI), especially its applications for structural health monitoring of aircraft bolt-joints and innovative approach of EMI prediction at loosening of bolt-joints.

Design/methodology/approach

This experimental study includes the results of a full-scale test of the Mi-8 helicopter tail beam, particularly, its bolt-joints of a beam with other parts of the structure. One of the connecting frames of the tail beam was equipped with piezoelectric transducers (PZT) glued on the surface of the frame near the bolts. The bolts' loosening was investigated by using the EMI technology.

Findings

It was demonstrated that loosening of the bolt-joint produces a significant and statistically stable change of the EMI metric. Presumably, both the small shift of resonance frequencies and the EMI magnitude and resistance change are caused mainly by damping variation at the bolt-joint loosening. In this analytical study, the 2D model of a constrained PZT is proposed. In contrast with the existing model, the modal decomposition analysis is used as a universal mean to express the dynamic properties and dynamic responses of both the transducer and the host structure. This approach, together with the finite element modal analysis, allows simulation of any complex system “PZT-host structure”. The model can be easily transformed also to the 3D one. The bolt-joint of the Mi-8 helicopter with the EMI measurement system was simulated by using the developed 2D model. The simulation results satisfactorily correspond to the test.

Practical implications

The results of this research can be used for implementation in the structural health monitoring of bolt-joints and other aerospace structural components.

Originality/value

The new experimental results on aircraft real bolt-joints were obtained. Especially significant is the original 2D model of the electromechanical impedance, based on the modal decomposition method, which can significantly improve the accuracy and the realistic description of the dynamic interaction between PZT and structure, as well as the dynamic response to the appearance of structural damage.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 86 no. 3
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 6 February 2017

Roman Ruzek, Martin Kadlec, Konstantinos Tserpes and Evaggelos Karachalios

Compression is critical loading condition for composite airframes. Compression behaviour of structures with or without damages is a weak point for composite fuselage…

Abstract

Purpose

Compression is critical loading condition for composite airframes. Compression behaviour of structures with or without damages is a weak point for composite fuselage panels. This is one of the reasons for need of continuous in-service health monitoring of composite structures. The purpose of this paper is to characterize the compression panel behaviour on the base of a developed and implemented structural health monitoring (SHM) system.

Design/methodology/approach

The SHM system based on fibre optic Bragg grating (FOBG) sensors and standard resistance strain gauges (SGs) was placed onto/into (embedded or bonded) three stiffened carbon fibre reinforced polymer (CFRP) fuselage panels. The FOBG sensor system was used to monitor the structural integrity of the reference, impacted, and fatigued panels under compression loading. Both barely visible impact damage and visible impact damage were created to evaluate their influence on the panel behaviour. The functionality of the SHM system was verified through mechanical testing.

Findings

Experimental data showed the presence of impact damages significantly changes the buckling modes development and deformation behaviour of the panels. Some differences between the optical and SG sensors during buckling were observed. The buckling waves and failure development were very well indicated during loading by all sensors located on the panel surface but not by the embedded sensors. Good agreement between the data from the SGs and FOBG sensors was achieved for all sensors placed on the stringers, which did not buckle. The good reliability of FOBG sensors during the fatigue and static testing up to panel failure was verified.

Originality/value

The paper gives information about different buckling behaviour of CFRP fuselage stiffened panels in compression. The paper gives detailed information about measured signals from different sensors based on their location on/in the panel structure for realistic loading scenario of composite aerostructures. The paper gives an integrated overview of sensors placement considering possibilities to predicate structure behaviour.

Details

International Journal of Structural Integrity, vol. 8 no. 1
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 30 September 2014

Yanhui Zhang and Wenyu Yang

– The purpose of this paper is to discuss the characteristics of several stochastic simulation methods applied in computation issue of structure health monitoring (SHM).

Abstract

Purpose

The purpose of this paper is to discuss the characteristics of several stochastic simulation methods applied in computation issue of structure health monitoring (SHM).

Design/methodology/approach

On the basis of the previous studies, this research focusses on four promising methods: transitional Markov chain Monte Carlo (TMCMC), slice sampling, slice-Metropolis-Hasting (M-H), and TMCMC-slice algorithm. The slice-M-H is the improved slice sampling algorithm, and the TMCMC-slice is the improved TMCMC algorithm. The performances of the parameters samples generated by these four algorithms are evaluated using two examples: one is the numerical example of a cantilever plate; another is the plate experiment simulating one part of the mechanical structure.

Findings

Both the numerical example and experiment show that, identification accuracy of slice-M-H is higher than that of slice sampling; and the identification accuracy of TMCMC-slice is higher than that of TMCMC. In general, the identification accuracy of the methods based on slice (slice sampling and slice-M-H) is higher than that of the methods based on TMCMC (TMCMC and TMCMC-slice).

Originality/value

The stochastic simulation methods evaluated in this paper are mainly two categories of representative methods: one introduces the intermediate probability density functions, and another one is the auxiliary variable approach. This paper provides important references about the stochastic simulation methods to solve the ill-conditioned computation issue, which is commonly encountered in SHM.

Details

Engineering Computations, vol. 31 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 19 May 2021

Anshul Sharma, Pardeep Kumar, Hemant Kumar Vinayak, Raj Kumar Patel and Suresh Kumar Walia

This study aims to perform the experimental work on a laboratory-constructed steel truss bridge model on which hammer blows are applied for excitation. The vibration…

Abstract

Purpose

This study aims to perform the experimental work on a laboratory-constructed steel truss bridge model on which hammer blows are applied for excitation. The vibration response signals of the bridge structure are collected using sensors placed at different nodes. The different damaged states such as no damage, single damage, double damage and triple damage are introduced by cutting members of the bridge. The masked noise with recorded vibration responses generates challenge to properly analyze the health of bridge structure.

Design/methodology/approach

The analytical modal properties are obtained from finite element model (FEM) developed using SAP2000 software. The response signals are analyzed in frequency domain by power spectrum and in time-frequency domain using spectrogram and Stockwell transform. Various low pass signal-filtering techniques such as variational filter, lowpass sparse banded (AB) filter and Savitzky–Golay (SG) differentiator filter are also applied to refine vibration signals. The proposed methodology further comprises application of Hilbert transform in combination with MUSIC and ESPRIT techniques.

Findings

The outcomes of SG filter provided the denoised signals using appropriate polynomial degree with proper selected window length. However, certain unwanted frequency peaks still appeared in the outcomes of SG filter. The SG-filtered signals are further analyzed using fused methodology of Hilbert transform-ESPRIT, which shows high accuracy in identifying modal frequencies at different states of the steel truss bridge.

Originality/value

The sequence of proposed methodology for denoising vibration response signals using SG filter with Hilbert transform-ESPRIT is a novel approach. The outcomes of proposed methodology are much refined and take less computational time.

Details

Journal of Engineering, Design and Technology , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 4 January 2019

Cansu Karatas, Boray Degerliyurt, Yavuz Yaman and Melin Sahin

Structural health monitoring (SHM) has become an attractive subject in aerospace engineering field considering the opportunity to avoid catastrophic failures by detecting…

Abstract

Purpose

Structural health monitoring (SHM) has become an attractive subject in aerospace engineering field considering the opportunity to avoid catastrophic failures by detecting damage in advance and to reduce maintenance costs. Fibre Bragg Grating (FBG) sensors are denoted as one of the most promising sensors for SHM applications as they are lightweight, immune to electromagnetic effects and able to be embedded between the layers of composite structures. The purpose of this paper is to research on and demonstrate the feasibility of FBG sensors for SHM of composite structures.

Design/methodology/approach

Applications on thin composite beams intended for SHM studies are presented. The sensor system, which includes FBG sensors and related interrogator system, and manufacturing of the beams with embedded sensors, are detailed. Static tension and torsion tests are conducted to verify the effectiveness of the system. Strain analysis results obtained from the tests are compared with the ones obtained from the finite element analyses conducted using ABAQUS® software. In addition, the comparison between the data obtained from the FBG sensors and from the strain gauges is made by also considering the noise content. Finally, fatigue test under torsion load is conducted to observe the durability of FBG sensors.

Findings

The results demonstrated that FBG sensors are feasible for SHM of composite structures as the strain data are accurate and less noisy compared to that obtained from the strain gauges. Furthermore, the convenience of obtaining reliable data between the layers of a composite structure using embedded FBG sensors is observed.

Practical implications

Observing the advantages of the FBG sensors for strain measurement will promote using FBG sensors for damage detection related to the SHM applications.

Originality/value

This paper presents applications of FBG sensors on thin composite beams, which reveal the suitability of FBG sensors for SHM of lightweight composite structures.

Details

Aircraft Engineering and Aerospace Technology, vol. 92 no. 3
Type: Research Article
ISSN: 1748-8842

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Article
Publication date: 8 February 2011

Pietro Giorgio Lovaglio

The purpose of this paper is to discuss strategies for benchmarking patient safety using Lombardy region administrative archives. Patient safety indicators and statistical…

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786

Abstract

Purpose

The purpose of this paper is to discuss strategies for benchmarking patient safety using Lombardy region administrative archives. Patient safety indicators and statistical methods are presented that allow risk adjustment. The analysis benchmarks regional health structures, focusing on two patient safety indicators: failure to rescue; and death in low mortality diagnostic related group.

Design/methodology/approach

Data were drawn from a research project promoted by the Italian Agency of Regional Health Services in 2002 to furnish statistical evidence regarding adverse events based on Agency for Healthcare Research and Quality indicators and methods. Hierarchical models for an equitable benchmark analyses are proposed.

Findings

Empirical analysis shows that hierarchical approaches, based on comparing health structures within homogenous specialties, disaggregates and moderates failure to rescue variabilities existing between hospitals, especially in oncology, intensive care and general medicine.

Research limitations/implications

The paper proposes using hierarchical models for properly benchmarking health structures, resolving logistic regression drawbacks and limitations.

Practical implications

The paper strengthens the theory that accurate coding supported by software and administrative databases could provide a valuable and economical source for patient safety research.

Originality/value

The paper analyses and suggests strategies for consistent benchmark analyses based on patient safety outcomes, applicable to several situations and different health structure typologies.

Details

International Journal of Health Care Quality Assurance, vol. 24 no. 2
Type: Research Article
ISSN: 0952-6862

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Article
Publication date: 23 August 2021

Xiao Fang, Yajie Zeng, Feng Xiong, Jiang Chen and Fei Cheng

Seepage of the dam is an important safety problem, which may cause internal erosion of the structure. In the field of seepage monitoring in civil engineering, the…

Abstract

Purpose

Seepage of the dam is an important safety problem, which may cause internal erosion of the structure. In the field of seepage monitoring in civil engineering, the distributed optical fiber sensing technology based on the temperature tracing method has been paid more attention due to its unique advantages of high sensitivity, good stability and high resolution. The purpose of this paper is to make a review of the existing related research, so as to facilitate the later scholars to understand and further study more systematically.

Design/methodology/approach

In this paper, three kinds of commonly used distributed fiber temperature measurement technologies are introduced. Based on the working principle, monitoring system, theoretical analysis, experimental research and engineering application of the fiber seepage monitoring technology, the present situation of dam seepage monitoring based on distributed fiber is reviewed in detail and their advantages and disadvantages are compared.

Findings

The thermal monitoring technology of seepage measurement depends on the accuracy of optical fiber temperature measurement (including the accuracy of the system and the rationality of the discrimination method), the correct installation of optical fiber and the quantitative analysis of temperature data. The accuracy of the current monitoring system can basically meet the existing measurement requirements, but the correct installation of optical fiber and the calibration of temperature data need to be further studied for different discrimination methods, and this field has great research value.

Originality/value

At present, there are many applications and research studies of optical fiber sensing in the field of structural health monitoring, and there are also reviews of related aspects. However, there is little or no review only in the field of seepage monitoring. This paper summarizes the research and application of optical fiber sensing in the field of seepage monitoring. The possibility of the gradient method to find its new prospect with the development of monitoring systems and the improvement of temperature resolution is discussed. The idea of extending the seepage monitoring method based on distributed optical fiber thermal monitoring technology to other monitoring fields is also given in the paper.

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Article
Publication date: 3 June 2014

S. Masmoudi, A. El Mahi, R. El Guerjouma and S. Turki

The smaller sizes of current electronic devices suggest the feasibility of creating a smart composite structure using piezoelectric implant to monitor in-situ and…

Abstract

Purpose

The smaller sizes of current electronic devices suggest the feasibility of creating a smart composite structure using piezoelectric implant to monitor in-situ and in-service conditions the life of civil and aerospace structures. Piezoelectric (lead zirconate-titanate (PZT)) sensors embedded within laminates composites represent a new branch of engineering with the potential to greatly enhance the confidence and use of these materials. The paper aims to discuss these issues.

Design/methodology/approach

This study presents a health monitoring of laminates composites materials incorporating by piezoelectric (PZT) implant using acoustic emission (AE) technique. A series of specimens of laminate composite with and without embedded piezoelectric were tested in three-point bending tests in static and creep loading while continuously monitoring the response by the AE technique. The AE signals were analysed using the classification k-means method in order to identify the different damages and to follow the evolution of these various mechanisms for both types of materials (with and without embedded sensors).

Findings

Comparing embedded sensor to sensor mounted on the surface, the embedded sensor showed a much higher sensitivity. It was thus verified that the embedded AE sensor had great potential for AE monitoring in fibre reinforced composites structures.

Originality/value

Piezoelectric implant to monitor in-situ and in-service conditions the life of civil and aerospace structures.

Details

Multidiscipline Modeling in Materials and Structures, vol. 10 no. 1
Type: Research Article
ISSN: 1573-6105

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