scholarly journals Comparison of Sandstone Damage Measurements Based on Non-Destructive Testing

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5154
Author(s):  
Duohao Yin ◽  
Qianjun Xu
Keyword(s):  
Elastic Modulus ◽  
Wave Velocity ◽  
Damage Variable ◽  
The Other ◽  
P Wave ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
P Wave Velocity ◽  
Amplitude Attenuation ◽  
Non Destructive

Non-destructive testing (NDT) methods are an important means to detect and assess rock damage. To better understand the accuracy of NDT methods for measuring damage in sandstone, this study compared three NDT methods, including ultrasonic testing, electrical impedance spectroscopy (EIS) testing, computed tomography (CT) scan testing, and a destructive test method, elastic modulus testing. Sandstone specimens were subjected to different levels of damage through cyclic loading and different damage variables derived from five different measured parameters—longitudinal wave (P-wave) velocity, first wave amplitude attenuation, resistivity, effective bearing area and the elastic modulus—were compared. The results show that the NDT methods all reflect the damage levels for sandstone accurately. The damage variable derived from the P-wave velocity is more consistent with the other damage variables, and the amplitude attenuation is more sensitive to damage. The damage variable derived from the effective bearing area is smaller than that derived from the other NDT measurement parameters. Resistivity provides a more stable measure of damage, and damage derived from the acoustic parameters is less stable. By developing P-wave velocity-to-resistivity models based on theoretical and empirical relationships, it was found that differences between these two damage parameters can be explained by differences between the mechanisms through which they respond to porosity, since the resistivity reflect pore structure, while the P-wave velocity reflects the extent of the continuous medium within the sandstone.

scholarly journals Quality Assessment of Strengthened Concrete by FRP Laminates using Non-Destructive Testing

2020 ◽  
Vol 9 (3) ◽  
pp. 1179-1188
Keyword(s):  
Wave Velocity ◽  
Concrete Beams ◽  
Plain Concrete ◽  
P Wave ◽  
Flexural Behavior ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
P Wave Velocity ◽  
Externally Bonded ◽  
Non Destructive

A non-destructive testing program has been designed to evaluate the integrity of the bond strength of plain concrete beams strengthened by Glass Fiber Reinforced Polymer (GFRP) Laminates. A series of concurrent static load and non-destructive testing experiments were carried out in the materials and testing laboratory at the college of engineering, Mataria, Helwan University, Cairo, Egypt. A total of 90 plain concrete standard beam specimens of dimensions 150 mm x 150 mm x 750 mm were constructed in the laboratory with three different design strength categories (38, 45, and 50) MPa. The beam specimens were strengthened by externally bonded GFRP laminates with various number of layers namely (3, 5 and 7) layers. In addition, the effect of debonding of the GFRP laminates was investigated by simulating it by variation in voids between concrete and laminates namely, (0, 30 and 60%). This study investigates the effectiveness of externally bonded GFRP laminates on the flexural strength of plain concrete beams by using Ultrasonic Pulse Velocity (UPV) device before and during loading until failure and their effect on the p-wave velocities. Four-point flexural tests were performed on the concrete beams, strengthened with different layouts of GFRP laminates and different percentage of voids at the concrete-laminate interface. The capacity of the beams and p-wave velocity were investigated. It was found that as the percentage of voids decreased, the capacity of strengthened concrete beams increased linearly. The reduction in voids enhanced the beam flexural behavior and controlled tension crack propagation. In addition, it was observed that use of GFRP laminates were more effective with higher concrete characteristic strength provided that debonding is not present. Finally, it was evident that the UPV technique was successful in detecting the variation in concrete p-wave velocity with strength and laminate layers variation.

scholarly journals Optimization of Rock Physics Models by Combining the Differential Effective Medium (DEM) and Adaptive Batzle-Wang Methods in “R” Field, East Java

2019 ◽  
Vol 17 (2) ◽  
Author(s):  
M. Wahdanadi Haidar ◽  
Reza Wardhana ◽  
M. Iskan ◽  
M. Syamsu Rosid
Keyword(s):  
Elastic Modulus ◽  
Wave Velocity ◽  
Carbonate Rocks ◽  
Effective Medium ◽  
Carbonate Reservoir ◽  
P Wave ◽  
S Wave ◽  
P Wave Velocity ◽  
Reservoir Conditions ◽  
Pore Types

The pore systems in carbonate reservoirs are more complex than the pore systems in clastic rocks. There are three types of pores in carbonate rocks: interparticle pores, stiff pores and cracks. The complexity of the pore types can lead to changes in the P-wave velocity by up to 40%, and carbonate reservoir characterization becomes difficult when the S-wave velocity is estimated using the dominant interparticle pore type only. In addition, the geometry of the pores affects the permeability of the reservoir. Therefore, when modelling the elastic modulus of the rock it is important to take into account the complexity of the pore types in carbonate rocks. The Differential Effective Medium (DEM) is a method for modelling the elastic modulus of the rock that takes into account the heterogeneity in the types of pores in carbonate rocks by adding pore-type inclusions little by little into the host material until the required proportion of the material is reached. In addition, the model is optimized by calculating the bulk modulus of the fluid filler porous rock under reservoir conditions using the Adaptive Batzle-Wang method. Once a fluid model has been constructed under reservoir conditions, the model is entered as input for the P-wave velocity model, which is then used to estimate the velocity of the S-wave and the proportion of primary and secondary pore types in the rock. Changes in the characteristics of the P-wave which are sensitive to the presence of fluid lead to improvements in the accuracy of the P-wave model, so the estimated S-wave velocity and the calculated ratio of primary and secondary pores in the reservoir are more reliable.

Исследование случаев «аномального» затухания ультразвуковых колебаний в заготовках из никелевых жаропрочных сплавов

2020 ◽  
pp. 37-47
Author(s):  
М.А. Далин ◽  
В.Ю. Чертищев ◽  
И.С. Краснов ◽  
А.Н. Раевских
Keyword(s):  
Ultrasonic Attenuation ◽  
Signal Amplitude ◽  
Coarse Grained ◽  
Non Destructive Testing ◽  
Echo Signal ◽  
Destructive Testing ◽  
Workpiece Surface ◽  
Amplitude Attenuation ◽  
Non Destructive ◽  
Longitudinal Ultrasonic Wave

An ultrasonic non-destructive testing has found out a new phenomenon in several stamped forgings made from heat-resistant nickel alloys (Ni-superalloys) of two grades: local attenuation of the bottom echo signal amplitude, when the workpiece surface had large (over 20 mm) randomly located zones with significant (up to 1.5%) fluctuations of the longitudinal ultrasonic wave propagation velocity. On top of that, there were no various grain sizes or coarse-grained structures that usually lead to a an increase of a rate of ultrasonic attenuation in such alloys, and which triggers off a bottom echo signal amplitude attenuation. The Article states the studies carried out to explain the tangible reasons of the detected macroinhomogeneity of the velocity, and how it associated with a bottom signal amplitude attenuation.

scholarly journals Mechanical and Non-Destructive Testing of Plasterboards Subjected to a Hydration Process

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2405
Author(s):  
Zbigniew Ranachowski ◽  
Przemysław Ranachowski ◽  
Tomasz Dębowski ◽  
Adam Brodecki ◽  
Mateusz Kopec ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Bending Test ◽  
Material Strength ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Three Point Bending ◽  
Site Monitoring ◽  
Material Volume ◽  
Non Destructive ◽  
Material Porosity

The aim of this study was to investigate the effect of plasterboards’ humidity absorption on their performance. Specimens’ hydration procedure consisted of consecutive immersing in water and subsequent drying at room temperature. Such a procedure was performed to increase the content of moisture within the material volume. The microstructural observations of five different plasterboard types were performed through optical and scanning electron microscopy. The deterioration of their properties was evaluated by using a three-point bending test and a subsequent ultrasonic (ultrasound testing (UT)) longitudinal wave velocity measurement. Depending on the material porosity, a loss of UT wave velocity from 6% to 35% and a considerable decrease in material strength from 70% to 80% were observed. Four types of approximated formulae were proposed to describe the dependence of UT wave velocity on board moisture content. It was found that the proposed UT method could be successfully used for the on-site monitoring of plasterboards’ hydration processes.

scholarly journals Characterization of Ancient Marquetry Using Different Non-Destructive Testing Techniques

2021 ◽  
Vol 11 (17) ◽  
pp. 7979
Author(s):  
Henrique Fernandes ◽  
Jannik Summa ◽  
Julie Daudre ◽  
Ute Rabe ◽  
Jonas Fell ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Infrared Thermography ◽  
The Other ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
X Ray ◽  
Testing Techniques ◽  
Micro Tomography ◽  
Non Destructive

Non-destructive testing of objects and structures is a valuable tool, especially in cultural heritage where the preservation of the inspected sample is of vital importance. In this paper, a decorative marquetry sample is inspected with three non-destructive testing (NDT) techniques: air-coupled ultrasound, X-ray micro-tomography, and infrared thermography. Results from the three techniques were compared and discussed. X-ray micro-tomography presented the most detailed results. On the other hand, infrared thermography provided interesting results with the advantage of being cheap and easy in the deployment of the NDT method.

Application of the Non-Destructive Testing Method to Determine the Gmax of Bangkok Clay

2013 ◽  
Vol 418 ◽  
pp. 157-160 ◽  
Author(s):  
Keeratikan Piriyakul
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Field Test ◽  
Shear Wave Velocity ◽  
Non Destructive Testing ◽  
Bender Element ◽  
Destructive Testing ◽  
Testing Method ◽  
Bender Element Test ◽  
Non Destructive

This article presents the application of the non-destructive testing method (so called Bender element test) to measure the shear wave velocity and determine the maximum shear modulus of soft Bangkok clay samples. This research proposes the bender element technique to measure the shear wave velocity by means of piezoelectric ceramic sensors. The details of the bender element test were clearly explained. The laboratory bender element test data of the shear wave velocity were compared with the field test results and show that the field propagating waves pass along layers of higher stiffness while the laboratory test data were performed on small, possible less stiff material. The inversion calculation of the shear wave velocity in the field test is based on a linear elastic isotropic assumption which is not valid for the Bangkok subsoil and might be a second reason for the noticed differences in velocity.

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