Experimental Study on Basalt Fiber Crack Resistance of Asphalt Concrete Based on Acoustic Emission

In this study, the semicircle three-point bending tests of ordinary asphalt concrete and basalt fiber asphalt concrete were carried out and acoustic emission parameters were collected during the test. The differences of the characteristics of acoustic emission parameters between basalt fiber asphalt concrete and ordinary asphalt concrete were analyzed, and the damage stages were divided based on the variation of acoustic emission parameters; Rise Angle and Average Frequency were introduced to study the cracking mode and crack resistance mechanism of asphalt concrete with basalt fiber. The results show that the acoustic emission parameters can well represent the toughening and crack resistance effect of basalt fiber in asphalt concrete, and the damage stages can be divided into three stages: microcrack initiation stage, fracture stage, and residual stage. The duration of the fracture stage and the load resistance time of the specimen were greatly prolonged. The proportion of shear events in the whole failure process increased greatly after the basalt fibers were added, especially in the fracture stage, which reduced the tensile failure tendency of the specimens, and thus improved the bending and tensile performance of the specimens and played a toughening and crack resistance role in the fracture stage.

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Research on Failure Characteristics of Concrete Three-Point Bending Beams with Preexisting Cracks in Different Positions Based on Numerical Simulation

Geofluids ◽

10.1155/2021/7892312 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Liuqun Zhao ◽

Li Zheng ◽

Hui Qin ◽

Tiesuo Geng ◽

Yonggang Tan ◽

...

Keyword(s):

Acoustic Emission ◽

Bearing Capacity ◽

Failure Modes ◽

Failure Process ◽

Engineering Application ◽

Tensile Failure ◽

Engineering Structures ◽

Failure Characteristics ◽

Three Point Bending ◽

Wide Range

Concrete three-point bending beams with preexisting cracks are widely used to study the growth process of I-II mixed mode cracks. Studying the failure characteristics of preexisting cracks at different locations on concrete three-point bending beams not only has important scientific significance but also has a wide range of engineering application backgrounds in the safety assessment of engineering structures. In this paper, through several numerical experiments, the influence of preexisting cracks at different positions on the failure characteristics of concrete three-point bending beams is studied, and three typical failure modes are obtained. The failure process of the specimens with three typical failure modes is discussed in detail, and it is pointed out that the crack failure mode is tensile failure. The change trends of bearing capacity, acoustic emission quantity, and acoustic emission energy of three typical failure modes are analyzed. The maximum bearing capacity, the maximum acoustic emission quantity, and energy of three failure modes of concrete three-point bending beams generally show an increasing trend.

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Numerical tests on thermal cracking characteristics of rocks with different scales

Advances in Mechanical Engineering ◽

10.1177/1687814018792142 ◽

2018 ◽

Vol 10 (8) ◽

pp. 168781401879214 ◽

Cited By ~ 1

Author(s):

Yang Xiao ◽

Rui Zhao ◽

Qing-Xiang Huang ◽

Jun Deng ◽

Jun-Hui Lu

Keyword(s):

Acoustic Emission ◽

Thermal Destruction ◽

Thermal Damage ◽

Process Analysis ◽

Failure Process ◽

Acoustic Emissions ◽

Thermal Cracking ◽

Tensile Failure ◽

Failure Patterns ◽

Different Diameters

Realistic failure process analysis, a thermal software simulation, was used to explore the scale effect of thermal cracking of rock under the thermal–mechanical coupling loading. The patterns and characteristics of thermal destruction were analyzed by simulating the thermal cracking of rocks with the same diameter different lengths, the same length but different diameters, and the same size ratio but different sizes (same length/diameter ratio but with different diameters). The acoustic emission and energy changes were also studied during thermal destruction. The results represented that the main forms of thermal cracking are tensile failure and shear failure. The smaller the scale is (length, diameter, and size), the more complex the pattern of thermal damage exhibited as failure patterns of inverted “S” or “V.” With the increasing scale, thermal damage models were simpler. The elastic modulus was determined by the diameter of specimens, and the peak stress was determined by the length of specimens. Overall, as the scale increased, the stress intensity decreased, but the number of acoustic emissions and acoustic emission energy and the corresponding accumulation increased.

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Investigation on Pore-Fracture of Coal and Its Influence Mechanism on Tensile Failure Behavior of Coals with Bursting Proneness

Geofluids ◽

10.1155/2021/7574305 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Yutao Li ◽

Qingwei Guo ◽

Xunchen Liu ◽

Yaodong Jiang ◽

Bo Zhang ◽

...

Keyword(s):

Acoustic Emission ◽

Spatial Distribution ◽

Failure Mode ◽

Failure Process ◽

Elastic Strain Energy ◽

Tensile Failure ◽

Failure Behavior ◽

Secondary Fracture ◽

Deformation And Failure ◽

Influence Mechanism

Both computed tomography (CT) and notched semicircular bend (NSCB) tests are performed for coals with high and medium bursting proneness to extract the scientific expression of pore-fracture and its influence mechanism on the tensile failure behavior. The acoustic emission (AE) parameters in the sample during loading and failure are monitored, and the influence mechanism of pore-fracture on tensile failure behavior of coal is analyzed. The result illustrates that the spatial distribution feature of the pore-fracture in coals with high and medium bursting proneness is extremely different. The deformation and failure mode of the coals are affected by many factors, loading mode, notch depth and width, mechanical properties of matrix and minal, spatial distribution feature of pore-fracture, etc. The influence of primary pore-fracture in the coal on the extension and penetration of the secondary fracture could be divided into two types: bifurcation and promotion, which would cause different local damage in the sample and affect the final failure mode. The feature of acoustic emission parameters indicates that the deformation and failure process of a sample under loading could be divided into four stages: compaction stage, elastic deformation stage, displacement plastic growth stage, and post peak failure stage, which is the result of comprehensive action of many factors. The evolution process of secondary fracture is accompanied by the dissipation of elastic strain energy and the intensification of internal damage of coal, which reflects the failure process of coal.

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Acoustic emission characteristics and crack resistance of basalt fiber reinforced concrete under tensile load

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.125442 ◽

2021 ◽

Vol 312 ◽

pp. 125442

Author(s):

Liyun Yang ◽

Huanzhen Xie ◽

Dongbin Zhang ◽

Fei Zhang ◽

Changyu Lin ◽

...

Keyword(s):

Acoustic Emission ◽

Reinforced Concrete ◽

Crack Resistance ◽

Basalt Fiber ◽

Tensile Load ◽

Fiber Reinforced Concrete ◽

Emission Characteristics ◽

Fiber Reinforced

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The Study of Identification Method for the Welding Defect Source of Low-Alloy High-Strength Steel Based on AE Technology

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.467-469.1580 ◽

2011 ◽

Vol 467-469 ◽

pp. 1580-1585 ◽

Cited By ~ 5

Author(s):

Yan Tao Dou ◽

Xiao Li Xu ◽

Wei Wang ◽

Si Qin Pang

Keyword(s):

Acoustic Emission ◽

High Strength Steel ◽

Failure Process ◽

Strain Curve ◽

High Strength ◽

Peak Frequency ◽

Average Frequency ◽

Bending Test ◽

Characteristic Parameters ◽

Deformation Stages

Three-bending test has been performed on the standard specimen and welding specimen with defect of low-alloy and high-strength steel in order to simulate the failure process of structural parts under loading, and the AE activities (number of hits) and stress-strain curve were measured during the whole loading process. The law of acoustic emission signals at different deformation stages has been investigated and the relation between AE characteristic parameters and the different deformation stages has been established. The typical AE waveforms such as friction noise, plastic deformation, welding microcrack initiation and propagation are obtained, which are analyzed by using spectrum characteristics analytical method. The spectrum characteristic parameters such as average frequency, peak frequency and frequency centroid, energy percentage of frequency spectrum part I and III of the typical AE defect signals are extracted, the distributing range of which are initially set. Study shows these five parameters have a closely relation with the nature of the AE signals, and based on these characteristics parameters different AE sources can be preliminary identified correctly. The study can provide some guidance to the practical application of AE acoustic emission technology in the industrial field.

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Mechanical Properties and Crack Classification of Basalt Fiber RPC Based on Acoustic Emission Parameters

Applied Sciences ◽

10.3390/app9183931 ◽

2019 ◽

Vol 9 (18) ◽

pp. 3931 ◽

Cited By ~ 4

Author(s):

Hanbing Liu ◽

Shiqi Liu ◽

Peilei Zhou ◽

Yuwei Zhang ◽

Yubo Jiao

Keyword(s):

Mechanical Properties ◽

Acoustic Emission ◽

Univariate Analysis ◽

Basalt Fiber ◽

Average Frequency ◽

Fiber Content ◽

Reactive Powder ◽

Non Destructive

The workability and mechanical properties of basalt fiber reactive powder concrete (BFRPC) were investigated by univariate analysis. The acoustic emission (AE) was used as a non-destructive technique to reveal the damage characterization of concrete samples of varying basalt fiber content. The fracture stages and modes of specimens during flexural test were determined by AE parameters. The content of silica fume, quartz sand and basalt fiber of 0.4, 1.3 and 10 kg/m3, respectively, was found related to optimal improvements in mechanical strength. As for the characteristics of fracture, it was found that the fiber content was a significant determinant, and the key AE parameters, namely, hits, energy and amplitude, were found related to the damage stage of specimens. Furthermore, rise time (RA) and average frequency (AF) were found to have opposite trends during loading while their variation related to the fracture modes of BFRPC.

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Acoustic Emission Characteristics and Damage Mechanisms Investigation of Basalt Fiber Concrete with Recycled Aggregate

Materials ◽

10.3390/ma13184009 ◽

2020 ◽

Vol 13 (18) ◽

pp. 4009

Author(s):

Guodong Li ◽

Li Zhang ◽

Fengnian Zhao ◽

Jiaqi Tang

Keyword(s):

Acoustic Emission ◽

Coarse Aggregate ◽

Failure Process ◽

Basalt Fiber ◽

Recycled Concrete ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Fine Aggregate ◽

Aggregate Concrete ◽

Fiber Concrete

This paper presents the compression failure process of basalt fiber concrete with recycled aggregate and analyzes the main factors of basalt fiber and recycled aggregate affecting the compressive strength of recycled concrete. The damage mechanism of recycled aggregate concrete is analyzed by the acoustic emission technique. With the method of acoustic emission (AE) b-value analysis, the evolution and failure process of recycled concrete from the initial defect microcrack formation to the macroscopic crack is studied. Based on the AE clustering analysis method, the damage state of recycled concrete under load grade is investigated. Finally, the failure mode of recycled concrete is explored according to the RA-AF correlation method. The results show that when the concrete reaches the curing age, the strength grade of basalt fiber regenerated coarse aggregate concrete is the highest. The basalt fiber increases the strength of regenerated fine concrete by 4.5% and the strength of coarse concrete by 5%, and reduces the strength of fully recycled aggregate concrete by 6.7%. The b-value divides concrete into three stages: initial damage, stable development of internal damage, and internal damage. The variation of AE energy, count, and event number is related to AE activity and crack growth rate. Matrix cracking is the main damage state of concrete, which is greatly affected by the strength of cement mortar. The load grade of fiber cracking in fully recycled aggregate, recycled fine aggregate, and recycled coarse aggregate concrete is 65, 90, and 85%, respectively. Basalt fiber increases the tensile failure event point of recycled concrete and delays the cracking of recycled concrete under compression. When the load grades of fully recycled fiber, recycled fine aggregate fiber, and recycled coarse aggregate fiber concrete are 65–95, 90–100, and 85–100%, respectively, the tensile failure activity increases.

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Evaluation of the mechanical properties of Inconel 718 to SCM 440 dissimilar friction welding through real-time monitoring of the acoustic emission system

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/1464420721993838 ◽

2021 ◽

pp. 146442072199383

Author(s):

Yu Sik Kong ◽

Muralimohan Cheepu ◽

Jin-Kyung Lee

Keyword(s):

Acoustic Emission ◽

Friction Welding ◽

Inconel 718 ◽

Low Voltage ◽

Dissimilar Materials ◽

Average Frequency ◽

Very High Frequency ◽

Cumulative Count ◽

Emission System ◽

Very High

Friction welding was chosen for its versatility in the joining of dissimilar materials with high quality. The aim of this study is to determine the optimal welding conditions for attaining quality joints by using online monitoring of acoustic emission system signals. During friction welding, the formation of cracks, defects, or any abnormalities in the joining process which have a detrimental effect on the joints quality was identified. The most widely used materials in the aerospace industry—Inconel 718 and molybdenum steel—were joined by friction welding. The precision of the joints, internal defects, and quality are major concerns for aerospace parts. The results of the present research determined the optimal welding conditions for high tensile strength by nondestructively inducing acoustic emission signals. During friction time and upset time periods, the typical waveforms and frequency spectrum of the acoustic emission signals were recorded, and their energy level, average frequency, cumulative count, and amplitude were analyzed. Both cumulative count and amplitude were found to be useful parameters for deriving the optimal welding conditions. In the initial stage of friction welding, a very high voltage of continuous form was generated with frequency characteristics of 0.44 MHz and 0.54 MHz. The signals generated during the upset stage had a low voltage, but a very high frequency of 1.56 MHz and 1.74 MHz with a burst-type signal. The amplitude of the signal generated for the optimally welded joints was about 100 dB at the friction time and about 45 dB at the upset time.

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