Stress wave communication in concrete: I. Characterization of a smart aggregate based concrete channel

Siu, Sam; Ji, Qing; Wu, Wenhao; Song, Gangbing; Ding, Zhi

doi:10.1088/0964-1726/23/12/125030

Cited by 51 publications

(38 citation statements)

References 19 publications

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“…Enabled by the piezoelectric effect, a PZT transducer can be used as an actuator [59,60] or as a sensor [61,62]. PZT transducers have other advantages, such as wide bandwidth [63][64][65][66], fast response, and low cost. Therefore, PZT transducers are often be used to generate and detect stress waves in an SHM system [67][68][69][70].…”

Section: Discussion On Real-time Damage Monitoringmentioning

confidence: 99%

Damage Analyses of Replaceable Links in Eccentrically Braced Frame (EBF) Subject to Cyclic Loading

2019

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In the current design of steel eccentrically braced frames (EBFs), the yielding link is coupled with the floor beam. This causes the design of cross-sectional dimensions of links to be enlarged, resulting in over-designed structures and foundations, and increasing the cost of the overall structure. In addition, the beams are forecast to sustain severe damage through repeated inelastic deformations under design-level earthquakes, and thus the structure may require extensive repair or need to be replaced. To improve upon these drawbacks, a shear device with replaceable links based on EBFs was designed. The hysteresis curve, the stress distribution, and the deformation of the specimen were obtained by cyclic loading tests of the eight replaceable links. The energy dissipation behavior, the bearing capacity, the failure modes, and the plastic rotation angle of those specimens were analyzed. The results indicated clearly that the links in this shear device had inelastic deformation concentrated in the link showing very stable hysteresis behavior, and damaged links were replaced easily as end-plate connections were adopted. The energy dissipation capacity and the plastic rotation angle of the specimens were mainly dependent on the arrangement of stiffener, length ratio, and welding access holes. Experimental studies performed in this research and the related damage analyses reveal that cracks are the major causes of damage to the EBF and there is a lack of research on real-time monitoring of the onset and development of these cracks in EBF structures. As a future work, this paper proposes a piezoceramic patch transducer-based active sensing approach to monitor the crack onset and development of the EBF when subjected to dynamic loadings.

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Section: Discussion On Real-time Damage Monitoringmentioning

confidence: 99%

Damage Analyses of Replaceable Links in Eccentrically Braced Frame (EBF) Subject to Cyclic Loading

2019

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“…However, the strain gauge sensors that were used cannot monitor these types of damages in real time. With the recent development of smart aggregates in structure damage monitoring [59][60][61][62][63][64] and the application of piezoceramic transducer transducer-based in health monitoring of steel structures [65][66][67][68], the authors will explore health monitoring and damage detection of eccentric braced steel frames while using the easy-to-operate smart aggregate and easy-to-install piezoceramic patch transducers in the future work.…”

Section: Discussionmentioning

confidence: 99%

Experimental Study on Energy Dissipation Performance and Failure Mode of Web-Connected Replaceable Energy Dissipation Link

et al. 2019

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In the current design method of the eccentrically braced frame structure, the energy dissipation link and the frame beam are both designed as a whole. It is difficult to accurately assess the degree of damage through this method, and it is also hard to repair or replace the energy dissipation link after strong seismic events. Meanwhile, the overall design approach will increase the project’s overall cost. In order to solve the above mentioned shortcomings, the energy dissipation link is designed as an independent component, which is separated from the frame beam. In this paper, the energy dissipation link is bolted to the web of the frame beam. Both finite element simulation and test study of eight groups of energy dissipation links have been completed to study their mechanical behaviors, and the energy dissipation links have been studied in the aspects of length, cross section, and stiffener spacing. The mechanical behaviors include the energy dissipation behavior, bearing capacity, stiffness, and plastic rotation angle. The results indicate clearly that the hysteretic loop of links in the test and finite element analysis is relatively full. By comparing the experimental and finite element simulation data, it can be found that the general shape and trend of hysteretic loop, skeleton curve, and stiffness degradation curve are basically the same. The experiment data explicitly shows that the energy dissipation link of web-connected displays good ductility and stable energy dissipation ability. In addition, the replaceable links possess good rotational capacity when the minimum rotation angle of each specimen in the test is 0.16 rad. The results of the experiment show that the energy dissipation capacity of the link is mainly related to the section size and the stiffening rib spacing of the link. The energy dissipation ability and deformation ability of the link is poorer as the section size becomes larger; meanwhile, these abilities are reduced with the decrease of the stiffening spacing. The experiment result shows that the damage and excessive inelastic deformations are concentrated in the link to avoid any issues for the rest of the surrounding elements, and the links can be easily and inexpensively replaced after strong seismic events. The results are thought provoking, as they provide a theoretical basis for the further study of the eccentrically braced frame structure with replaceable links of web-connected. In future work, the author aims to carry out his studies through optimized design methodology based on the yielding criterion.

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“…In addition to the structural health monitoring function, the smart aggregate can be used to perform early-age concrete strength monitoring [8,9], impact detection [10], seismic detection [11], and soil freeze-thaw monitoring [12], demonstrating that SAs are multi-functional devices. In previous studies, SAs have been successfully implemented for structural health monitoring of various concrete structures under different loading cases including: a concrete bridge bent-cap under static loading [13], a concrete frame under static loading [14,15], a shear wall under reversed cyclic loading [16], columns under seismic loading [17], stress wave base communication in concrete structures [18,19] and columns under reversed cyclic loading [20,21]. The purpose of this project was to further verify the effectiveness of the smart aggregate in health monitoring of a RC concrete column tested with pseudo-dynamic loads.…”

Section: Introductionmentioning

confidence: 99%

Cyclic Crack Monitoring of a Reinforced Concrete Column under Simulated Pseudo-Dynamic Loading Using Piezoceramic-Based Smart Aggregates

Robert²,

et al. 2016

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Structural health monitoring is an important aspect of maintenance for bridge columns in areas of high seismic activity. In this project, recently developed piezoceramic-based transducers, known as smart aggregates (SA), were utilized to perform structural health monitoring of a reinforced concrete (RC) bridge column subjected to pseudo-dynamic loading. The SA-based approach has been previously verified for static and dynamic loading but never for pseudo-dynamic loading. Based on the developed SAs, an active-sensing approach was developed to perform real-time health status evaluation of the RC column during the loading procedure. The existence of cracks attenuated the stress wave transmission energy during the loading procedure and reduced the amplitudes of the signal received by SA sensors. To detect the crack evolution and evaluate the damage severity, a wavelet packet-based structural damage index was developed. Experimental results verified the effectiveness of the SAs in structural health monitoring of the RC column under pseudo-dynamic loading. In addition to monitoring the general severity of the damage, the local structural damage indices show potential to report the cyclic crack open-close phenomenon subjected to the pseudo-dynamic loading.

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Stress wave communication in concrete: I. Characterization of a smart aggregate based concrete channel

Cited by 51 publications

References 19 publications

Damage Analyses of Replaceable Links in Eccentrically Braced Frame (EBF) Subject to Cyclic Loading

Damage Analyses of Replaceable Links in Eccentrically Braced Frame (EBF) Subject to Cyclic Loading

Experimental Study on Energy Dissipation Performance and Failure Mode of Web-Connected Replaceable Energy Dissipation Link

Cyclic Crack Monitoring of a Reinforced Concrete Column under Simulated Pseudo-Dynamic Loading Using Piezoceramic-Based Smart Aggregates

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