Modal macro-strain vector based damage detection methodology with long-gauge FBG sensors

2009 ◽  
Author(s):  
Bin Xu ◽  
Chongwu W. Liu ◽  
Sami F. Masri
Keyword(s):  
Damage Detection ◽  
Strain Vector ◽  
Fbg Sensors

Identification of modal macro-strain vector based on distributed long-gage FBG sensors under ambient vibration

2010 ◽  
Author(s):  
Wan Hong ◽  
Caiqian Yang ◽  
Zhishen Wu ◽  
Yufeng Zhang ◽  
Chunfeng Wan ◽  
...  
Keyword(s):  
Ambient Vibration ◽  
Strain Vector ◽  
Fbg Sensors

scholarly journals Comparative Study of Damage Detection Methods Based on Long-Gauge FBG for Highway Bridges

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3623 ◽  
Author(s):  
Shi-Zhi Chen ◽  
De-Cheng Feng ◽  
Wan-Shui Han
Keyword(s):  
Comparative Study ◽  
Damage Detection ◽  
Highway Bridges ◽  
Gauge Length ◽  
Detection Methods ◽  
Noise Levels ◽  
Damage Scenarios ◽  
Road Roughness ◽  
Parametric Studies ◽  
Fbg Sensors

Damage detection of highway bridges is a significant part of structural heath monitoring. Conventional accelerometers or strain gauges utilized for damage detection have many shortcomings, especially their monitoring gauge length being too short, which would result in poor damage detection results. Under this circumstance, long-gauge FBG sensors as a novel optical sensor were developed to measure the macro-strain response of the structure. Based on this sensor, many derived damage detection methods were proposed. These methods exhibit various characteristics and have not been systematically compared. As a result, it is difficult to evaluate the state of the art and also leads to confusion for users to select. Therefore, a strict comparative study on three representative methods using long-gauge FBG was carried out. First, these methods’ theoretical backgrounds and formats were reformulated and unified for better comparison. Then, based on validated vehicle–bridge coupling simulation, these methods’ performances were tested through a series of parametric studies including various damage scenarios, vehicle types, speeds, road roughness and noise levels. The precision and reliability of three methods have been thoroughly studied and compared.

scholarly journals A Novel Fabry-Pérot Optical Sensor for Guided Wave Signal Acquisition

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1728
Author(s):  
Cheng Xu ◽  
Zahra Sharif Khodaei
Keyword(s):  
Damage Detection ◽  
Guided Waves ◽  
Detection System ◽  
Guided Wave ◽  
Signal Acquisition ◽  
System A ◽  
Fabry Perot ◽  
Fbg Sensors ◽  
Improved Performance ◽  
New Sensors

In this paper, a novel hybrid damage detection system is proposed, which utilizes piezoelectric actuators for guided wave excitation and a new fibre optic (FO) sensor based on Fabry-Perot (FP) and Fiber Bragg Grating (FBG). By replacing the FBG sensors with FBG-based FP sensors in the hybrid damage detection system, a higher strain resolution is achieved, which results in higher damage sensitivity and higher reliability in diagnosis. To develop the novel sensor, optimum parameters such as reflectivity, a wavelength spectrum, and a sensor length were chosen carefully through an analytical model of the sensor, which has been validated with experiments. The sensitivity of the new FBG-based FP sensors was compared to FBG sensors to emphasize the superiority of the new sensors in measuring micro-strains. Lastly, the new FBG-based FP sensor was utilized for recording guided waves in a hybrid setup and compared to the conventional FBG hybrid sensor network to demonstrate their improved performance for a structural health monitoring (SHM) application.

Structural damage detection with distributed long-gauge FBG sensors under multi-point excitations

2019 ◽  
Vol 28 (9) ◽  
pp. 095023 ◽  
Author(s):  
Zhenwei Zhou ◽  
Chunfeng Wan ◽  
Bo Wen ◽  
Siyuan Li ◽  
Lei Zhao ◽  
...  
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Structural Damage Detection ◽  
Fbg Sensors

Temperature Effects on Guided Ultrasonic Wave Sensing for Dry Cast Storage Health Monitoring

2016 ◽  
Author(s):  
Xiaoyi Sun ◽  
Linlin Ma ◽  
Stephen Howden ◽  
Bin Lin ◽  
Lingyu Yu
Keyword(s):  
Damage Detection ◽  
Temperature Effect ◽  
Ultrasonic Wave ◽  
Health Monitoring ◽  
Temperature Effects ◽  
Storage System ◽  
Active Sensor ◽  
Different Temperatures ◽  
Piezoelectric Wafer ◽  
Fbg Sensors

This paper discusses the temperature effects of using guided ultrasonic wave sensing in damage detection for structural health monitoring (SHM) for nuclear dry cast storage system (DCSS). The sensing capability of GUW under temperature effect is investigated and presented in this paper. Two types of sensors are studied: (a) piezoelectric wafer active sensor (PWAS) and (b) optical fiber Bragg grating (FBG) sensors. Temperature effect on the free sensors was first tested in experiments. Pristine specimens instrumented with PWAS are then investigated through sensing tests at selected temperatures. Parameters in wave modes are obtained and evaluated for changes in the waveforms at different temperatures. The investigation continues to evaluate the damage detection capability of GUW under temperature influence. The potential of using GUW for damage detection with temperature effect applied for DCSS application is discussed and concluded in the end, as well as suggestions for further work.

scholarly journals Optimum Placement of Long Gauge FBG Sensor in Reinforced Concrete Bridge: A Case Study

2021 ◽  
Vol 2090 (1) ◽  
pp. 012162
Author(s):  
Sayantani Lala ◽  
Nandini Basumallick ◽  
Palas Biswas ◽  
Somnath Bandyopadhyay
Keyword(s):  
Reinforced Concrete ◽  
Damage Detection ◽  
Health Monitoring ◽  
Bridge Deck ◽  
Structural Integrity ◽  
Moving Load ◽  
Warning System ◽  
Element Model ◽  
Fibre Bragg Grating ◽  
Fbg Sensors

Abstract In the world today, civil infrastructure plays a major role in the advancement of the modern age. They are huge in scale, complex in their behaviour and create great impact in everyday life. To ensure safety of these structures, assessment of their structural integrity is an important and challenging task. The sole purpose of structural health monitoring is to detect damage in the structures and suggest suitable rehabilitation measures. Various sensors are employed to achieve the task of damage detection and establish a warning system to avoid failure of the structures. For large structures, long-gauge Fibre Bragg Grating (FBG) sensors which are sensitive to the global behaviour, can be suitably used for this purpose. However, health monitoring of a structure with large number of sensors is expensive and hence there is a need to optimize the number of sensors deployed to minimize the cost of the exercise without compromising on performance assessment. For this purpose, several optimization algorithms are available in literature. In this study, the Effective Independence Method (EIM) which optimizes the response of the structure based on modal analysis, is used to derive the Optimum sensor placement (OSP) protocol for a reinforced concrete (RC) bridge-deck in Poland, the geometry of which has been taken from literature. This will enable the placement of 40 long gauge FBG sensors in regions for efficient damage response in the bridge-deck. Further, the optimum orientation of the sensors is further validated with a finite element model of the bridge-deck, where a moving load is applied, and strains are recorded in the sensing fibre in both longitudinal (along length) and transverse (along breadth) alignments. It has been found that long gauge FBG sensors placed in the transverse direction are more efficient in damage detection than when they are placed longitudinally.

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