Research on high-resolution distributed fiber optic stress sensor for landslide monitoring

2008 ◽  
Author(s):  
Zhiyong Dai ◽  
Yongzhi Liu ◽  
Lixun Zhang ◽  
Zhonghua Ou ◽  
Ce Zhou
Keyword(s):  
High Resolution ◽  
Fiber Optic ◽  
Landslide Monitoring ◽  
Stress Sensor

Distributed fiber optic stress sensor system based on P-OFDR

2010 ◽  
Author(s):  
Zhiyong Dai ◽  
Xiaoxia Zhang ◽  
Zengshou Peng ◽  
Jianfeng Li ◽  
Zhonghua Ou ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Sensor System ◽  
Stress Sensor

scholarly journals A low-cost, human-like, high-resolution, tactile sensor based on optical fibers and an image sensor

2018 ◽  
Vol 15 (4) ◽  
pp. 172988141878363 ◽  
Author(s):  
Utku Büyükşahin ◽  
Ahmet Kırlı
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Fiber Optic ◽  
Low Cost ◽  
Experimental Studies ◽  
Main Idea ◽  
Tactile Sensor ◽  
Image Sensor ◽  
Sensor Design ◽  
Tactile Sensors

Tactile sensors are commonly a coordinated group of receptors forming a matrix array meant to measure force or pressure similar to the human skin. Optic-based tactile sensors are flexible, sensitive, and fast; however, the human fingertip’s spatial resolution, which can be regarded as the desired spatial resolution, still could not be reached because of their bulky nature. This article proposes a novel and patented optic-based tactile sensor design, in which fiber optic cables are used to increase the number of sensory receptors per square centimeter. The proposed human-like high-resolution tactile sensor design is based on simple optics and image processing techniques, and it enables high spatial resolution and easy data acquisition at low cost. This design proposes using the change in the intesity of the light occured due to the deformation on contact/measurement surface. The main idea is using fiber optic cables as the afferents of the human physiology which can have 9 µm diameters for both delivering and receiving light beams. The variation of the light intensity enters sequent mathematical models as the input, then, the displacement, the force, and the pressure data are evaluated as the outputs. A prototype tactile sensor is manufactured with 1-mm spatial and 0.61-kPa pressure measurement resolution with 0–15.6 N/cm2 at 30 Hz sampling frequency. Experimental studies with different scenarios are conducted to demonstrate how this state-of-the-art design worked and to evaluate its performance. The overall accuracy of the first prototype, based on different scenarios, is calculated as 93%. This performance is regarded as promising for further developments and applications such as grasp control or haptics.

High-resolution Fiber Optic Seismic Sensor Array for Intrusion Detection of Subway Tunnel

2018 ◽  
Author(s):  
Jiantao Huang ◽  
Wentao Zhang ◽  
Wenhui Huang ◽  
Wenzhu Huang ◽  
Lixin Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Intrusion Detection ◽  
Sensor Array ◽  
Fiber Optic ◽  
Subway Tunnel

scholarly journals Load-Independent Characterization of Plate Foundation Support Using High-Resolution Distributed Fiber-Optic Sensing

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3518 ◽  
Author(s):  
Asmus Skar ◽  
Assaf Klar ◽  
Eyal Levenberg
Keyword(s):  
High Resolution ◽  
Mechanical Model ◽  
Fiber Optic ◽  
Soil Parameters ◽  
Soil Reaction ◽  
Model Parameters ◽  
Strain Sensing ◽  
Soil Response ◽  
Monitoring Strategies

The evaluation of soil reaction in geotechnical foundation systems such as concrete pavements, mat- and raft foundations is a challenging task, as the process involves both the selection of a representative mechanical model (e.g., Winkler, Continuum, Pasternak, etc.) and identify its prevailing parameters. Moreover, the support characteristics may change with time and environmental situation. This paper presents a new method for the characterization of plate foundation support using high-resolution fiber-optic distributed strain sensing. The approach involves tracking the location of distinct points of zero and maximum strains, and relating the shift in their location to the changes in soil reaction. The approach may allow the determination of the most suited mechanical model of soil representation as well as model parameters. Routine monitoring using this approach may help to asses the degradation of the subsoil with time as part of structural health monitoring strategies. In this paper, fundamental expressions that relate between the location of distinct strain points and the variation of soil parameters were developed based on various analytical foundation support models. Finally, as an initial validation step and to underpin the idea basics, the proposed method was successfully demonstrated on a simple mechanical setup. It is shown that the approach allows for load-independent characterization of the soil response and, in that sense, it is superior to common identification methods.

Quantifying progressive failure of micro-anchored fiber optic cable–sand interface via high-resolution distributed strain sensing

2020 ◽  
Vol 57 (6) ◽  
pp. 871-881 ◽  
Author(s):  
Cheng-Cheng Zhang ◽  
Hong-Hu Zhu ◽  
Su-Ping Liu ◽  
Bin Shi ◽  
Gang Cheng
Keyword(s):  
High Resolution ◽  
Fiber Optic ◽  
Progressive Failure ◽  
Interfacial Shear Stress ◽  
Interfacial Shear ◽  
Deformation Monitoring ◽  
Shear Stresses ◽  
Fiber Optic Cable ◽  
Geotechnical Monitoring ◽  
Inclusion Interaction

Distributed fiber optic sensing (DFOS) is gaining increasing interest in geotechnical monitoring. By using soil-embedded fiber optic cables, strain profiles as well as deformation patterns of geotechnical infrastructures can be captured. Probing the fiber optic cable–soil interfacial behavior is vital to the advancement of DFOS-based geotechnical monitoring and our understanding of the soil–inclusion interaction mechanism. To this aim, laboratory pullout tests were performed to investigate the progressive failure of the interface between micro-anchored cables and the surrounding sand. High-resolution strain profiles recorded using Brillouin optical time-domain analysis (BOTDA) not only elucidated the influence of anchorage on strain measurements, but also allowed the classical soil–inclusion interaction problem to be studied in detail. Interfacial shear stresses calculated from step-like strain profiles provided clear evidence of the contribution of each micro-anchor to the pullout resistance. The cable–soil contact is a combination of overall bonding and point fixation depending on the level of mobilized interfacial shear stress, and therefore the validity of measured strains is correlated to a three-stage process of interface failure. This study also shows that installing heat-shrink tubes on the fiber optic cable is a rapid, low-cost, effective approach to make an anchored DFOS system for deformation monitoring of earth structures.

High-resolution absolute frequency referenced fiber optic sensor for quasi-static strain sensing

2010 ◽  
Vol 49 (21) ◽  
pp. 4029 ◽  
Author(s):  
Timothy T.-Y. Lam ◽  
Jong H. Chow ◽  
Daniel A. Shaddock ◽  
Ian C. M. Littler ◽  
Gianluca Gagliardi ◽  
...  
Keyword(s):  
High Resolution ◽  
Fiber Optic ◽  
Fiber Optic Sensor ◽  
Strain Sensing ◽  
Absolute Frequency ◽  
Static Strain ◽  
Optic Sensor
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