Numerical Simulation of Impact-Echo Method Identify the Depth of Honeycomb Damage in Unballasted Track

Zhou, Chang Sheng; Wang, Ping; Hu, Zhi Peng; Zhu, Hao

doi:10.4028/www.scientific.net/amm.584-586.2060

Cited by 7 publications

(8 citation statements)

References 4 publications

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“…Due to the actual operation condition of HSR, the surface temperature feld of the track slab is determined by the surrounding environment. An energy balance mode is then formed between the track slab and the surrounding air [26]. It includes the following three typical forms of heat transfer in thermodynamics: (1) heat conduction, i.e., heat transfer and heat storage between solid structures such as concrete slab, CA mortar, and concrete basement in the slab track structure;…”

Section: Principle Of Surface Crack Detectionmentioning

confidence: 99%

“…where T(crack) is the temperature at the crack on the slab surface and T(sound) represents the temperature at noncrack (sound) area on the surface. Figure 2 illustrates the principle of IRT detection of the surface cracks on concrete slabs [26]. On this basis, the temperature diference between the crack and noncrack area on the slab surface can be described as the color diference between these areas on the thermal images.…”

Section: Principle Of Crack Detection By Irtmentioning

confidence: 99%

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A Feasibility Analysis of the Infrared Thermography Technique in Surface Crack Detection for High‐Speed Rail Slab Track

Luo

et al. 2023

Mathematical Problems in Engineering

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The surface crack on track slab is the main cause of the service reliability deterioration of the high-speed rail (HSR) slab track. To realize the rapid and accurate detection of these cracks, infrared thermography (IRT) can be regarded as an effective way in HSR application. However, the performance of IRT can be significantly affected by the testing environment. This study aims to analyze the feasibility of IRT in crack detection for HSR slab track by investigating the key factors affecting the detection accuracy. Firstly, the principle of IRT in detecting surface crack of track slab is given, and the key factors influencing the detection performance are discussed. Considering the difficulty in conducting field tests for slab tracks, this study establishes a finite element (FE) model to simulate the temperature field of track slab with surface cracks. This model is verified by using the field measurement results of track slab temperature. With the FE model, the effects of detection time, ambient temperature, and sensitivity of the thermal imager on the detection accuracy are revealed. The results show that, during the window time for track maintenance (0:00 am–3:00 am), the difference of temperature between crack areas and noncrack areas gradually increases with time, so it is recommended to conduct detection during 2:00–3:00 am; under the condition of no auxiliary heat source, the crack detection is suggested to be arranged in summer with a high incidence of crack; the minimum limit of thermal sensitivity of thermal imager is below 108mk@25°C. The findings in this research can offer guidance for the implementation of IRT-based crack detection for HSR slab crack.

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Section: Principle Of Surface Crack Detectionmentioning

confidence: 99%

Section: Principle Of Crack Detection By Irtmentioning

confidence: 99%

A Feasibility Analysis of the Infrared Thermography Technique in Surface Crack Detection for High‐Speed Rail Slab Track

Luo

et al. 2023

Mathematical Problems in Engineering

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“…To study effect of defects, a piece of foam board was embedded into the left half of three SG samples, which were compared with the SG sample without defect (the right half). To ensure that the embedded foam board could be detected [7], width of the foam board was set to be 150 mm. Thickness of the foam board was 20 mm and it was embedded at 30 mm away from the segment-grouting interface ( Figure 3).…”

Section: Experimental Studymentioning

confidence: 99%

“…Impact echo method [3][4][5][6] is a structural nondestructive testing technology based on transient stress wave. It impacts the concrete surface by a steel ball or hammer as an exciter to produce longitudinal wave (P wave) and transverse wave (S wave) in the concrete structure as well as Rayleigh wave (R wave) on the concrete surface [7,8]. Stress waves will form echoes through propagation and reflections in concrete [9,10].…”

Section: Introductionmentioning

confidence: 99%

Experimental Research and Numerical Simulation on Grouting Quality of Shield Tunnel Based on Impact Echo Method

Yao

Chen

2016

Shock and Vibration

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To identify shield grouting quality based on impact echo method, an impact echo test of segment-grouting (SG) test piece was carried out to explore effect of acoustic impedance of grouting layers and grouting defects on impact echo law. A finite element numerical simulation on the impact echo process was implemented. Test results and simulation results were compared. Results demonstrated that, under some working conditions, finite element simulation results and test results both agree with theoretical values. The acoustic impedance ratio of SG material influenced the echo characteristics significantly. But thickness frequency could not be detected under some working conditions because the reflected energy is weak. Frequency feature under grouting defects was more complicated than that under no grouting defects.

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“…Those defects generally appear in bed slab due to technical defects and impact environmental conditions. However, the method has been found accurate to identify the honeycomb damage in slab track [11]. In order to plan a successful testing program, Nicholas J. Carino in 2015 summarized the principles of IE [12].…”

Section: Introductionmentioning

confidence: 99%

Detection of deep and shallow defects in Concrete Filled Steel Tube Using Impact-Echo Method

Twite,

Fei

2023

Preprint

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Concrete Filled Steel Tube (CFST) is widely used in construction due to its good bearing performance, low cost and excellent structural seismic performance. Quality problems such as voids and debonding are often encounters in the process of pouring CFST. They significantly reduce the bearing capacity and ductility of specimens, and adversely affect the restraining effect of concrete. Such internal hidden defects cannot be visually identified. However, Non-destructive Testing Technique (NDT) is required. This paper employed the Impact Echo (IE) method to determine the location of defects in various types of concrete structures. Since the IE method was developed in the 1980s and used to test concrete structures, there have been little researches on defect detection in CFST. Therefore, this paper studies the square CFST specimens with defects located at different depths which are tested using the IE method. The Fast Fourier Transform (FFT) was employed to detect the location of defects by analyzing waveform and frequency spectrum. In addition, the CFST finite element model under more working conditions has been established, including internal defects of different depths and widths. The analysis of frequency distribution provides more details about the depth and location of the defects. A time-frequency analysis using Wavelet Transform was introduced in this study to assess the reliability of the IE method. According to the models carried out in this work it is demonstrated that IE method has been able to detect defects in Concrete Filled Steel Tube.

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Numerical Simulation of Impact-Echo Method Identify the Depth of Honeycomb Damage in Unballasted Track

Cited by 7 publications

References 4 publications

A Feasibility Analysis of the Infrared Thermography Technique in Surface Crack Detection for High‐Speed Rail Slab Track

A Feasibility Analysis of the Infrared Thermography Technique in Surface Crack Detection for High‐Speed Rail Slab Track

Experimental Research and Numerical Simulation on Grouting Quality of Shield Tunnel Based on Impact Echo Method

Detection of deep and shallow defects in Concrete Filled Steel Tube Using Impact-Echo Method

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