scholarly journals Smart Aggregate-Piezoceramic Patch Combination for Health Monitoring of Concrete Structures

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Jinlei Zhao ◽  
Tengfei Bao ◽  
Shanying Chen ◽  
Tribikram Kundu
Keyword(s):  
Health Monitoring ◽  
Concrete Beam ◽  
Damage Index ◽  
Concrete Structures ◽  
Signal Amplitude ◽  
Bending Test ◽  
Three Point Bending ◽  
Recorded Signal ◽  
Amplitude Fluctuations ◽  
Smart Aggregate

A new method combining an embedded smart aggregate and surface mounted piezoceramic patches is introduced for health monitoring of concrete structures. The smart aggregate is embedded in a concrete beam as an actuator (or transmitter), and piezoceramic patches are attached on the surface of the concrete beam as sensors. Two tests using the smart aggregate and the piezoceramic patches are conducted. The first test investigates the sensitivity of the recorded signal amplitude-frequency relation on the piezoceramic patches. To explain the significant amplitude fluctuations in the results, the possibility of resonance occurring in the piezoceramic patches in a certain frequency range is verified through finite element modeling. In the second test, a damage index is proposed to evaluate the health of concrete structures and a three-point bending test is conducted to induce damage in the concrete beam. It is observed that, with increasing severity of damage in the concrete beam, the recorded signal amplitude at the patches decreases gradually while the value of the damage index increases significantly. The experimental results show that the proposed method is an effective tool for health monitoring of concrete structures.

scholarly journals Microseismic Signal Characterization and Numerical Simulation of Concrete Beam Subjected to Three-Point Bending Fracture

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Nuwen Xu ◽  
Feng Dai ◽  
Chun Sha ◽  
Yingcheng Lei ◽  
Biao Li
Keyword(s):  
Concrete Beam ◽  
Process Analysis ◽  
Failure Process ◽  
Microseismic Monitoring ◽  
Bending Test ◽  
Hydropower Station ◽  
Mass Concrete ◽  
Physical Test ◽  
Deformation And Failure ◽  
Three Point Bending

To study the generation mechanism and failure mode of cracks in mass concrete, microseismic monitoring is conducted on the fracture processes of the three-point bending roller compacted concrete (RCC) beam of Guanyinyan hydropower station. The spectrum characteristics of microseismic signals in different deformation and failure stages of the concrete beam are analyzed, and the identification method of the fracture stages and crack propagation precursors of concrete beam is established. Meanwhile, the Realistic Failure Process Analysis code (RFPA) is adopted to simulate and analyze the entire failure processes of concrete beam from its cracks initiation, development, propagation, and coalescence, until macroscopic fractures formation subjected to three-point bending test. The relation curve of the load, loaded displacement, and acoustic emission (AE) of concrete beam in the three-point bending test is also obtained. It is found that the failure characteristics of concrete beam obtained from numerical experiments agree well with the field physical test results. The heterogeneity of concrete is the major cause of zigzag propagation paths of beam cracks subjected to three-point bending tests. The results lay foundation for further exploring the formation mechanism of dam concrete cracks of Guanyinyan hydropower station.

Experimental and Analytical Studies for Impedance-Based Smart Health Monitoring of Concrete Structures

2006 ◽  
Vol 321-323 ◽  
pp. 170-173 ◽  
Author(s):  
Seung Hee Park ◽  
Sohaib Ahmad ◽  
Chung Bang Yun ◽  
Yong Rae Roh
Keyword(s):  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Concrete Beam ◽  
Concrete Structures ◽  
Plain Concrete ◽  
Surface Damage ◽  
Lead Zirconate ◽  
Damage Quantification ◽  
Analytical Studies ◽  
Before And After

This paper presents a feasibility study of an impedance-based damage detection technique using PZT (Lead-Zirconate-Titanate) patches for real-time health monitoring of concrete structures. The PZT patches are used to detect progressive surface damage on a plain concrete beam. Both experimental and analytical studies are carried out. For damage quantification, root-mean square deviations (RMSD) before and after damage are used as a damage indicator.

scholarly journals Damage Detection Using d15 Piezoelectric Sensors in a Laminate Beam Undergoing Three-Point Bending

Actuators ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 70 ◽  
Author(s):  
Hussain Altammar ◽  
Anoop Dhingra ◽  
Nathan Salowitz
Keyword(s):  
Lead Zirconate Titanate ◽  
Health Monitoring ◽  
Pearson Correlation ◽  
Ultrasonic Inspection ◽  
Lead Zirconate ◽  
Piezoelectric Transducers ◽  
Bending Test ◽  
Shear Mode ◽  
Three Point Bending ◽  
Damage Indices

A major inhibition to the widespread use of laminate structures is the inability of nondestructive testing techniques to effectively evaluate the bondline integrity. This work proposes and analyzes a bondline-integrity health monitoring approach utilizing shear-mode (d15) piezoelectric transducers. The d15 transducers were embedded in the bondlines of symmetric laminate structures to monitor and evaluate the bondline integrity using ultrasonic inspection. The d15 piezoelectric transducers made of lead zirconate titanate (PZT) enabled ultrasonic inspection of bonds by actuating and sensing antisymmetric waves in laminate structures. Design considerations, fabrication process, and experimental methods for testing a laminate specimen are presented. Designs included bondline-embedded d15 PZT piezoelectric transducers with surface-mounted transverse (d31) piezoelectric transducers for signal comparison. Defects in the bondline were created by a quasi-static three-point bending test, with results showing the ability of d15 piezoelectric transducers to detect bondline damage. Two damage indices based on Pearson correlation coefficient and normalized signal energy were implemented to evaluate the presence of damage and its severity. The experimental results demonstrate the ability of bondline-embedded d15 piezoelectric transducers to be used as actuators and sensors for ultrasonic health monitoring of bondline integrity. A comparison between surface-mounted d31 PZT and bondline-embedded d15 PZT sensors was also conducted. It was seen that signals sensed by bondline-embedded d15 PZTs showed higher distortion due to bondline defects compared with the sensed signals from the surface-mounted d31 PZT.

scholarly journals A Novel Embeddable Tubular Piezoceramics-Based Smart Aggregate for Damage Detection in Two-Dimensional Concrete Structures

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1501 ◽  
Author(s):  
Weihang Gao ◽  
Hongnan Li ◽  
Siu Ho
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Health Monitoring ◽  
Concrete Structures ◽  
Shear Walls ◽  
Stress Waves ◽  
Time Of Arrival ◽  
Two Dimensional ◽  
Structural Health ◽  
Smart Aggregate

Due to their multiple advantages, piezoceramic materials have been widely used in structural health monitoring (SHM). Piezoceramic patch-based smart aggregate (SA) and spherical piezoceramic-based smart aggregate (SSA) have been developed for damage detection of concrete structures. However, the stress waves generated by these two types of transducers are limited by their geometry and are unsuitable for use in two-dimensional concrete structures (e.g., shear walls, floors and cement concrete pavements). In this paper, a novel embeddable tubular smart aggregate (TSA) based on a piezoceramic tube was designed, fabricated and tested for use in two-dimensional (2D) structures. Due to its special geometry, radially uniform stress waves can be generated, and thus the TSA is suitable for damage detection in planar structures. The suitability of the transducer for use in structural health monitoring was investigated by characterizing the ability of the transducer to transmit and measure stress waves. Three experiments, including impedance analysis, time of arrival analysis and sweep frequency analysis, were conducted to test the proposed TSA. The experimental results show that the proposed TSA is suitable for monitoring the health condition of two-dimensional concrete structures.

scholarly journals Additive Manufacturing-Based In Situ Consolidation of Continuous Carbon Fibre-Reinforced Polycarbonate

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Carbon Fibre ◽  
Bending Test ◽  
Thermoplastic Composites ◽  
Experimental Investigations ◽  
Material Structure ◽  
Three Point Bending ◽  
Continuous Fibre ◽  
Local Material

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.

Effect of Concrete Mixture Composition on Acoustic Emission and Fracture Parameters Obtained from Three-Point Bending Test

2015 ◽  
Vol 1100 ◽  
pp. 152-155
Author(s):  
Libor Topolář ◽  
Hana Šimonová ◽  
Petr Misák
Keyword(s):  
Acoustic Emission ◽  
Bending Test ◽  
Mixture Composition ◽  
Three Point Bending ◽  
Concrete Mixtures ◽  
Fracture Parameters ◽  
Fracture Tests ◽  
Stress Behaviour ◽  
Bending Fracture ◽  
Fracture Processes

This paper reports the analysis of acoustic emission signals captured during three-point bending fracture tests of concrete specimens with different mixture composition. Acoustic emission is an experimental tool well suited for monitoring fracture processes in material. The typical acoustic emission patterns were identified in the acoustic emission records for three different concrete mixtures to further describe the under-the-stress behaviour and failure development. An understanding of microstructure–performance relationships is the key to true understanding of material behaviour. The acoustic emission results are accompanied by fracture parameters determined via evaluation of load versus deflection diagrams recorded during three-point bending fracture tests.

scholarly journals Experimental and Numerical simulation of a Three Point Bending Test of a Stainless Steel Beam

2021 ◽  
Vol 55 ◽  
pp. 1114-1121
Author(s):  
Daniel Jindra ◽  
Zdeněk Kala ◽  
Jiří Kala ◽  
Stanislav Seitl
Keyword(s):  
Numerical Simulation ◽  
Stainless Steel ◽  
Bending Test ◽  
Steel Beam ◽  
Three Point Bending

scholarly journals Fracture and Size Effect of PFRC Specimens Simulated by Using a Trilinear Softening Diagram: A Predictive Approach

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3795
Author(s):  
Fernando Suárez ◽  
Jaime C. Gálvez ◽  
Marcos G. Alberti ◽  
Alejandro Enfedaque
Keyword(s):  
Reinforced Concrete ◽  
Size Effect ◽  
A Priori ◽  
Plain Concrete ◽  
Specimen Size ◽  
Bending Test ◽  
Orientation Factor ◽  
Fibre Reinforced Concrete ◽  
Softening Function ◽  
Three Point Bending

The size effect on plain concrete specimens is well known and can be correctly captured when performing numerical simulations by using a well characterised softening function. Nevertheless, in the case of polyolefin-fibre-reinforced concrete (PFRC), this is not directly applicable, since using only diagram cannot capture the material behaviour on elements with different sizes due to dependence of the orientation factor of the fibres with the size of the specimen. In previous works, the use of a trilinear softening diagram proved to be very convenient for reproducing fracture of polyolefin-fibre-reinforced concrete elements, but only if it is previously adapted for each specimen size. In this work, a predictive methodology is used to reproduce fracture of polyolefin-fibre-reinforced concrete specimens of different sizes under three-point bending. Fracture is reproduced by means of a well-known embedded cohesive model, with a trilinear softening function that is defined specifically for each specimen size. The fundamental points of these softening functions are defined a priori by using empirical expressions proposed in past works, based on an extensive experimental background. Therefore, the numerical results are obtained in a predictive manner and then compared with a previous experimental campaign in which PFRC notched specimens of different sizes were tested with a three-point bending test setup, showing that this approach properly captures the size effect, although some values of the fundamental points in the trilinear diagram could be defined more accurately.

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