Three-Point Bending Test Evaluation of Concrete Specimens by Non-Traditional Analysis of Acoustic Emission Method

2016 ◽  
Vol 837 ◽  
pp. 198-202
Author(s):  
Luboš Pazdera ◽  
Libor Topolář ◽  
Tomáš Vymazal ◽  
Petr Daněk ◽  
Jaroslav Smutny
Keyword(s):  
Acoustic Emission ◽  
Signal Analysis ◽  
Measurement Data ◽  
Bending Test ◽  
Test Evaluation ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Time Frequency ◽  
Emission Signal

The aim of the paper is focused on the analysis of the mechanical properties of the concrete specimens with plasticizer at three point bending test by the signal analysis of the acoustic emission signal. The evaluations were compared the measurement and the results obtained with theoretical presumptions. The Joint Time Frequency Analysis applied on measurement data and its evaluation is described. It is well known that the Acoustic Emission Method is a very sensitive method to determine active cracks into structure. However, evaluation of acoustic emission signals is very difficult. A non-traditional method was used to signal analysis of burst acoustic emission signals recorded during three point bending test.

Evaluation of Acoustic Emission Events Generated at Three Point Bending of Different Concrete Specimens by Spectral Analysis

2016 ◽  
Vol 258 ◽  
pp. 485-488
Author(s):  
Lubos Pazdera ◽  
Libor Topolář ◽  
Petr Daněk ◽  
Jaroslav Smutny ◽  
Karel Mikulasek
Keyword(s):  
Acoustic Emission ◽  
Bending Test ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Direct Evaluation ◽  
Cement Ratio ◽  
Three Point Bending ◽  
Time Frequency ◽  
Frequency Domains ◽  
The Individual

The paper aims to the determine of the mechanical properties of the concrete specimens at three-point bending test by application of the Acoustic Emission Method. Recorded acoustic emission events generated during three-point loading have been chosen. Some frequency and joint time-frequency methods are applied to these records. Time series as acoustic emission events may be analyzed in the time, frequency, and/or time-frequency domains. The selection is based on the type of the signal in question, on the type of analysis to be used or the result achieved. In many applications, direct evaluation of the time-amplitude representation is neither easy nor advantageous. The individual mixtures were different in cement dosage and water-cement ratio based on how much the amount of cement was increased while maintaining consistency S2 according to EN 206.

The Assessment of High-Temperature Degraded Concrete Specimens of Different Mixtures by Acoustic Emission Method during Three-Point Bending Test and Pulse Velocity Method in Comparison with Destructive Tests

2017 ◽  
Vol 908 ◽  
pp. 88-93 ◽  
Author(s):  
Libor Topolář ◽  
Richard Dvořák ◽  
Luboš Pazdera
Keyword(s):  
Acoustic Emission ◽  
Building Materials ◽  
Pulse Velocity ◽  
Bending Test ◽  
Structural Components ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Live Loads ◽  
Non Destructive

One of the advantages of concrete over other building materials is its inherent fire-resistive properties. The concrete structural components still must be able to withstand dead and live loads without collapse even though the rise in temperature causes a decrease in the strength and modulus of elasticity for concrete and steel reinforcement. In addition, fully developed fires cause expansion of structural components and the resulting stresses and strains must be resisted. This paper reports the results of measurements by Acoustic Emission method during three-point bending test on concrete specimens. The Acoustic emission method is a non-destructive technique used widely for structural health monitoring purposes of structures. The sensors are mounted by beeswax on the surface of the material or structure to record the motion of the surface under the elastic excitation of the cracking sources. The concrete specimens were heated in a programmable laboratory furnace at a heating rate of 5 °C/min. The specimens were loaded at six temperatures, 200 °C, 400 °C, 600 °C, 800 °C, 1000 °C, and 1200 °C maintained for 60 minutes. The results are obtained in the laboratory.

The Analysis of Acoustic Emission Code and the Research of Acoustic Emission Signal of P355NL1 Under Low Temperature of −40°C

2014 ◽  
Author(s):  
Xiao Biao ◽  
Xiaoying Tang ◽  
Nie Liang ◽  
Yao Jianping ◽  
Li Jianrong
Keyword(s):  
Acoustic Emission ◽  
Low Temperature ◽  
Acoustic Emission Signal ◽  
Tensile Specimen ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Storage Vessel ◽  
Emission Signal ◽  
Whole Process ◽  
Specimen Test

The latest content of acoustic emission code GB/T18182-2012 are shown in this paper. The differences of GB/T18182-2012 and GB18182-2000 are summarized. Acoustic emission method was used to inspect the whole process of tensile specimen test under the temperature of 0°C, −20°C and −50°C. Based on the characteristics of the signal of different temperature condition, some difference of these signals was analyzed and discussed. By using the above result, acoustic emission was applied to inspect a drikold storage vessel.

scholarly journals Effect of Freeze–Thaw Cycling on the Failure of Fibre-Cement Boards, Assessed Using Acoustic Emission Method and Artificial Neural Network

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2181 ◽  
Author(s):  
Tomasz Gorzelańczyk ◽  
Krzysztof Schabowicz
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Acoustic Emission ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Freeze Thaw ◽  
Fibre Cement ◽  
Artificial Neural ◽  
Building Practice

This paper presents the results of investigations into the effect of freeze–thaw cycling on the failure of fibre-cement boards and on the changes taking place in their structure. Fibre-cement board specimens were subjected to one and ten freeze–thaw cycles and then investigated under three-point bending by means of the acoustic emission method. An artificial neural network was employed to analyse the results yielded by the acoustic emission method. The investigations conclusively proved that freeze–thaw cycling had an effect on the failure of fibre-cement boards, as indicated mainly by the fall in the number of acoustic emission (AE) events recognized as accompanying the breaking of fibres during the three-point bending of the specimens. SEM examinations were carried out to gain better insight into the changes taking place in the structure of the tested boards. Interesting results with significance for building practice were obtained.

scholarly journals Identification of the Degree of Degradation of Fibre-Cement Boards Exposed to Fire by Means of the Acoustic Emission Method and Artificial Neural Networks

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 656 ◽  
Author(s):  
Krzysztof Schabowicz ◽  
Tomasz Gorzelańczyk ◽  
Mateusz Szymków
Keyword(s):  
Neural Networks ◽  
Acoustic Emission ◽  
Artificial Neural Networks ◽  
Bending Strength ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Fibre Cement ◽  
Artificial Neural ◽  
Degree Of Degradation

This paper presents the results of research aimed at identifying the degree of degradation of fibre-cement boards exposed to fire. The fibre-cement board samples were initially exposed to fire at various durations in the range of 1–15 min. The samples were then subjected to three-point bending and were investigated using the acoustic emission method. Artificial neural networks (ANNs) were employed to analyse the results yielded by the acoustic emission method. Fire was found to have a degrading effect on the fibres contained in the boards. As the length of exposure to fire increased, the fibres underwent gradual degradation, which was reflected in a decrease in the number of acoustic emission (AE) events recognised by the artificial neural networks as accompanying the breaking of the fibres during the three-point bending of the sample. It was shown that it is not sufficient to determine the degree of degradation of fibre-cement boards solely on the basis of bending strength (MOR).

Correlation between Parameters of Acoustic Emission and Fracture Characteristics Obtained from Three-Point Bending Test

2015 ◽  
Vol 1124 ◽  
pp. 231-236
Author(s):  
Libor Topolář ◽  
Luboš Pazdera
Keyword(s):  
Acoustic Emission ◽  
Bending Test ◽  
Emission Method ◽  
Fracture Characteristics ◽  
Three Point Bending ◽  
Experimental Tool ◽  
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 method 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 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.

The Design of Bearing Monitoring System Based on Acoustic Emission Signal

2014 ◽  
Vol 716-717 ◽  
pp. 940-943
Author(s):  
Ke Huang ◽  
Zhi Kang Bu ◽  
Chi Zhang ◽  
Heng Lian Xie
Keyword(s):  
Acoustic Emission ◽  
Monitoring System ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Emission Signal ◽  
Bearing Fault Diagnosis ◽  
Bearing Condition Monitoring ◽  
Condition Monitoring System ◽  
Bearing Monitoring ◽  
Ae Signals

After experimental verification, in terms of low-speed bearing fault diagnosis, the acoustic emission method is superior to the traditional vibration method. In order to further the study of the correlation between AE signals and the bearing state, this article refers to the bearing condition monitoring system, and gives detailed parts models, the acoustic emission acquisition system, which provides help for further researches.

scholarly journals The effect of nano-additive TiO2 on the failure process of self-compacting concrete assessed using the acoustic emission method

2018 ◽  
Vol 174 ◽  
pp. 02003
Author(s):  
Paweł Niewiadomski
Keyword(s):  
Acoustic Emission ◽  
Failure Process ◽  
Physical And Mechanical Properties ◽  
Test Method ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Emission Signal ◽  
Critical Stresses ◽  
Literature Reviews ◽  
The Impact

Due to the new challenges posed to engineering constructions, as well as the principles of sustainable development, many laboratories around the world are carrying out works to improve the basic structural material that is concrete. There has recently been a lot of interest in modifying concrete with nano-sized particles. Literature reviews indicate that their addition significantly improves the physical and mechanical properties of the concrete that was obtained with their use. Until now, there is no knowledge of the effect of nano-additives on the process of destroying temporarily compressed concrete. One test method that enables the parameters that describe the stress failure of concrete to be determined is the acoustic emission method. This work fills the gap in the literature and presents the results of the author's own research on the impact of the use of different amounts of nano-additive TiO2 on the failure process of selfcompacting concrete that was made solely on the basis of granite aggregate. The stress failure of the tested concrete was described using the stress levels (determined using the acoustic emission method) that initiate the cracking σi and critical stresses σcr that delimit the tested process. The descriptors that were used for this purpose are the rate of counts and the average effective value of the acoustic emission signal.

scholarly journals Statistical Evaluation of Burning Rate Data of Composite Propellants Obtained from Acoustic Emission Technique

2021 ◽  
Vol 71 (1) ◽  
pp. 18-24
Author(s):  
Ehtasimul Hoque ◽  
Chandra Shekhar Pant ◽  
Sushanta Das
Keyword(s):  
Acoustic Emission ◽  
Burning Rate ◽  
Statistical Treatment ◽  
Measurement Data ◽  
Good Health ◽  
Rate Measurement ◽  
Acoustic Emission Method ◽  
Acoustic Emission Technique ◽  
Emission Method ◽  
Measurement Variability

The acoustic emission technique has been considered to be one of the most reliable and robust methods for the measurement of the steady burning rate of composite propellants. In this work, attempts were made to quantify the measurement variability of the burning rate of composite solid propellants by acoustic emission method using statistical tools. A total of 1100 individual measurements were subjected to statistical treatment. The combination of confidence interval and repeatability limit delineated the extent of natural dispersion in the burning rate measurement data. The very high coefficient of variation values for the propellant compositions, having a burning rate of more than 25 mm s–1 raised concerns about the suitability of the acoustic emission method for high burning rate compositions. The Reliability interval approach was employed to determine the statistically significant sample size for different composite propellants having a burning rate range of 5–31 mm s–1. The entire set of data was screened for identification of outlying observation using the Dixon Q test, and the extent of contamination was quantified. Moreover, the application of statistical techniques could have far-reaching implications for quality control perspectives of burning rate measurement by acoustic emission and could be implemented as reference tolerance limits and preventive measures for ensuring the good health of the instrument as well as propellant processing.

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