scholarly journals Structural health monitoring of two-way slabs based on random decrement technique

2021 ◽  
Author(s):  
Azita Pourrastegar
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Failure Modes ◽  
Ambient Vibration ◽  
Experimental Investigations ◽  
Monitoring Method ◽  
Structural Health ◽  
Random Decrement Technique ◽  
Random Decrement ◽  
Extent Of Damage

The current research attempts to explore the feasible use of a Structural Health Monitoring method for a two-way slab system through the effective vibration based damage diagnostic technique of Random Decrement (RD). Experimental investigations have been conducted on a total of four reinforced concrete two-way slab specimens. The slabs behaviour was examined under static loading. The results were presented in terms of load-deflection relationship at service and ultimate load, crack pattern and failure modes. At each stage of loading, the ambient vibration excitation test has been performed to investigate the extent of damage at the cracking, yield, and ultimate states through changes in dynamic parameters obtained from RD signatures. Additional applications of RD technique were performed on two-way slabs, first, to explore the location of damage by Multi-Channel Random Decrement using FBG sensor arrays. Secondly, RD technique was utilized to evaluate the extent of damage under successive equal dynamic impacts.

scholarly journals Structural health monitoring of two-way slabs based on random decrement technique

2021 ◽  
Author(s):  
Azita Pourrastegar
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Failure Modes ◽  
Ambient Vibration ◽  
Experimental Investigations ◽  
Monitoring Method ◽  
Structural Health ◽  
Random Decrement Technique ◽  
Random Decrement ◽  
Extent Of Damage

The current research attempts to explore the feasible use of a Structural Health Monitoring method for a two-way slab system through the effective vibration based damage diagnostic technique of Random Decrement (RD). Experimental investigations have been conducted on a total of four reinforced concrete two-way slab specimens. The slabs behaviour was examined under static loading. The results were presented in terms of load-deflection relationship at service and ultimate load, crack pattern and failure modes. At each stage of loading, the ambient vibration excitation test has been performed to investigate the extent of damage at the cracking, yield, and ultimate states through changes in dynamic parameters obtained from RD signatures. Additional applications of RD technique were performed on two-way slabs, first, to explore the location of damage by Multi-Channel Random Decrement using FBG sensor arrays. Secondly, RD technique was utilized to evaluate the extent of damage under successive equal dynamic impacts.

scholarly journals Image Analysis Applications for Building Inter-Story Drift Monitoring

2020 ◽  
Vol 10 (20) ◽  
pp. 7304
Author(s):  
Yuan-Sen Yang ◽  
Qiang Xue ◽  
Pin-Yao Chen ◽  
Jian-Huang Weng ◽  
Chi-Hang Li ◽  
...  
Keyword(s):  
Image Analysis ◽  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Power Plants ◽  
Deformation Monitoring ◽  
Ambient Vibration ◽  
Single Camera ◽  
Monitoring Method ◽  
Structural Health ◽  
Structural Responses

Structural health monitoring techniques have been applied to several important structures and infrastructure facilities, such as buildings, bridges, and power plants. For buildings, accelerometers are commonly used for monitoring the accelerations induced by ambient vibration to analyze the structural natural frequencies for further system identification and damage detection. However, due to the relatively high cost of the accelerometers and data acquisition systems, accelerometer-based structural health monitoring systems are challenging to deploy in general buildings. This study proposed an image analysis-based building deformation monitoring method that integrates a small single-board computer, computer vision techniques, and a single-camera multiple degree-of-freedom algorithm. In contrast to other vision-based systems that use multiple expensive cameras, this method is designed for a single camera configuration to simplify the installation and maintenance procedures for practical applications. It is designed to monitor the inter-story drifts and torsional responses between the ceiling and floor of a story that is being monitored in a building, aiming to maximize the monitored structural responses. A series of 1:10 reduced scale static and dynamic structural experiments demonstrated that the proposed method and the device prototype are capable of analyzing images and structural responses with an accuracy of 0.07 and 0.3 mm from the results of the static and dynamic experiments, respectively. As digital imaging technology has been developing dramatically, the accuracy and the sampling rates of this method can be improved accordingly with the development of the required hardware, making this method practically feasible for an increasing number of applications for building structural monitoring.

Detecting Damage in Graphite/Epoxy Composites Using Impedance-Based Structural Health Monitoring

2004 ◽  
Vol 1-2 ◽  
pp. 185-190 ◽  
Author(s):  
Benjamin L. Grisso ◽  
Daniel M. Peairs ◽  
Daniel J. Inman
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Tensile Load ◽  
Mechanical Impedance ◽  
Monitoring Method ◽  
Structural Health ◽  
Static Tensile Loading ◽  
Before And After ◽  
Static Tensile ◽  
Extent Of Damage

The impedance-based structural health monitoring method is used to successfully detect different damage mechanisms in composites and to correlate the changes in impedance measurements with the changes in the structure. Specifically, graphite/epoxy composite samples are manufactured and tested. Piezoceramic (PZT) patches are attached to the composite coupons to actuate the structure with high-frequency excitations. Bonding the patches to the sample allows changes in the structural mechanical impedance to be monitored with the electrical impedance of the PZT. Samples are tested using quasi-static tensile loading to introduce damage. To determine the extent of damage incurred, impedance signatures are acquired before and after the tensile load is applied. A change in impedance from the baseline shows the presence of damage. The amount of damage is characterized using a damage metric. Radiography is used to verify the extent of damage.

scholarly journals Structural Health Monitoring of Bridges Via Energy Harvesting Sensor Nodes

2016 ◽  
Vol 10 (1) ◽  
pp. 136-149 ◽  
Author(s):  
N. Bonessio ◽  
P. Zappi ◽  
G. Benzoni ◽  
T. Simunic Rosing ◽  
G. Lomiento
Keyword(s):  
Structural Health Monitoring ◽  
Energy Harvesting ◽  
Health Monitoring ◽  
State Of The Art ◽  
Sensor Nodes ◽  
Structural Performance ◽  
Structural Health ◽  
Random Decrement Technique ◽  
Random Decrement ◽  
Wireless Energy Harvesting

This paper deals with the application of novel sensing technologies to an existing Structural Health Monitoring (SHM) system for bridges. A vibration based SHM algorithm already in use to detect the structural performance degradation of a suspension highway bridge is modified to investigate the feasibility of replacing traditional wired accelerometers with state of the art wireless energy-harvesting sensors. The remodeled SHM algorithm benefits from the sensor nodes’ ability to support automated triggering and data pre-processing. The Random Decrement technique was included in the algorithm as a pre-processing tool to simultaneously reduce noise and amount of stored and transmitted data. Simulations based on available data were used to calibrate the triggering strategy, to verify the effectiveness of the data pre-processing, and to demonstrate power consumption improvements arising from the algorithm modification.

scholarly journals Structural Health Monitoring Method of Pantograph–Catenary System Based on Strain Response Inversion

2021 ◽  
Vol 9 ◽  
Author(s):  
Sheng Liu ◽  
Yibo Wei ◽  
Yongxin Yin ◽  
Tangzheng Feng ◽  
Jinbao Lin
Keyword(s):  
Structural Health Monitoring ◽  
Contact Force ◽  
Health Monitoring ◽  
Data Consistency ◽  
Inversion Method ◽  
Maximum Speed ◽  
Strain Response ◽  
Monitoring Method ◽  
Structural Health ◽  
Catenary System

Pantograph-catenary system provides electric energy for the subway lines; its health status is essential to the serviceability of the vehicle. In this study, a real-time structural health monitoring method based on strain response inversion is proposed to calculate the magnitude and position of the dynamic contact force between the catenary and pantograph. The measurement principle, calibration, and installation detail of the fiber Bragg grating (FBG) sensors are also presented in this article. Putting this monitoring system in use, an application example of a subway with a rigid overhead catenary is given to demonstrate its performance. The pantograph was monitored and analyzed, running underground at a maximum speed of 80 km/h. The results show that the strain response inversion method has high measurement accuracy, good data consistency, and flexibility on sensor installation. It can accurately calculate the magnitude and location of the contact force exerted on the pantograph.

scholarly journals Effect of Adhesive Debonding on the Performance of Piezoelectric Sensors in Structural Health Monitoring Systems

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5070 ◽  
Author(s):  
Liu ◽  
Xu ◽  
Li ◽  
Wang ◽  
Zhang
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Research Work ◽  
Piezoelectric Sensor ◽  
Systematic Investigation ◽  
Monitoring Method ◽  
Structural Health ◽  
Negative Effect ◽  
Inherent Frequency ◽  
Slow Rise

Piezoelectric (PZT) ceramic elements are often subjected to complex loads during in- service lifetime in structural health monitoring (SHM) systems, and debonding of both excitation actuators and receiving sensors have a negative effect on the monitoring signals. A first systematic investigation of debonding behaviors by considering actuators and sensors simultaneously was performed in this paper. The debonding areas of actuators were set in different percentage range from 0% to 70%, and sensors in 0%, 20%, 40% and 60%. The signal-based monitoring method was used to extract the characteristic parameters of both the amplitudes and phases of received signals. Experimental results revealed that as the debonding areas of the actuators increase, the normalized amplitude appears a quick decrease before 35% debonding area of actuators and then a slow rise until 60% of debonding reached. This may be explained that the 35% debonding turning point correspond to the coincidence of the excitation frequencies of peripheral actuators with the inherent frequency of the central piezoelectric sensor, and the 60% be the result of the maximum ability of piezoelectric sensor. The degrees of debonding of actuators and sensors also have significant influence on the phase angle offset, with large debonding of actuators increases the phase offset sharply. The research work may provide useful information for practical monitoring of SHM systems.

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