Figure 14 - uploaded by Kanji Ono
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(a) The attenuation spectra for a large Al 2024 block with TDM-1 (purple) and TDM-2 (green) along with linear fits (dotted lines). Also shown are spectra for direct contact (blue), for a thin sample (brown), and for a 307 mm distance (red). (b) Quadratic attenuation spectra for a Cu plate. Red: L direction, quadratic fit (Equation (22a)); blue: T direction, quadratic fit (Equation (23a)).
Source publication
In this paper, ultrasonic attenuation of engineering materials is evaluated comprehensively, covering metals, ceramics, polymers, fiber-reinforced composites, wood, and rocks. After verifying two reliable experimental methods, 336 measurements are conducted and their results are tabulated. Attenuation behavior is determined over broadband spectra,...
Citations
... Therefore, it was decided to use a thin polycarbonate (PC) sheet with thickness corresponding to resonant frequency of the leaf. Sheet thickness can be measured using micrometer, it is easy to handle, its properties have been well studied using ultrasound [38]- [42], so reference values are available. ...
... Unfortunately, ultrasonic properties usually are measured at high frequencies, therefore had to be derived from available values. Ultrasound attenuation in PC, according to [38] is 638 dB/m/MHz or 43.5 Np/m at 650 kHz. Ultrasound velocity of PC, according to [39] is 2235 m/s at 4 MHz, 2225 m/s at 1 MHz at 25 °C. ...
The air-coupled resonance ultrasound spectroscopy (RUS) of thin plate thickness, density, ultrasound velocity and attenuation measurement are affected by air parameters. If air parameters are left unaccounted errors will occur. Conventional thermometer measurements are not efficient because temperature can vary faster than temperature sensor response. Technique for air parameters estimation and compensation of the RUS inverse solution results is proposed. The ultrasound delay over known distance is used for velocity in air estimation. There is no need for the additional measurement: the propagation time between transducers can be obtained from RUS calibration measurement. Ultrasound velocity in air is then used for temperature estimation. These measurements are augmented by pressure sensor measurement for air density estimation. Evaluation of the attainable measurement errors and analysis of uncertainties under such compensation was carried out using simulated signals. Sensitivity coefficients for every parameter were derived and attainable errors evaluated for temperature range from -5 °C to +40 °C and atmospheric pressure range from 94 kPa to 105 kPa. It was concluded that the relative uncertainty of sample attenuation, ultrasound velocity attenuation, density and thickness could be reduced approximately 22 times compared to case when air parameters are assumed to be equal to those in normal conditions. Experimental verification used 2 mm polycarbonate plate, measured values were compared against reported data. Experiment confirmed the efficiency of the proposed compensation: thickness estimation bias errors were reduced 17 times, bias errors for density were reduced 15 times and velocity estimation bias errors were reduced 5 times.
... In cement paste, attenuation estimates extended up to 6 MHz, showing an attenuation coefficient of about 140 dB/m at 1 MHz. Ono's investigations into mortar samples revealed attenuation coefficients in the range of 220-250 dB/m at 1 MHz [27,28]. Further studies explored the influence of void content on mortar's attenuation coefficient, indicating increases in attenuation with greater void content. ...
... This trend is consistent across bridges in both the longitudinal and transverse directions, suggesting a clear preference for focusing measurements within the low-frequency range. The results discussed align well with the observations made by other researchers, as mentioned briefly in Section 2. Specifically, Ono reported attenuation coefficients in the range of 220-250 dB/m at 1 MHz for mortar specimens, with a predominantly linear relationship observed within the attenuation spectra [27,28]. Based on these findings, it's feasible to make an approximate extrapolation to the lower frequency range, which is the focus of this study. ...
Acoustic emission monitoring (AEM) has emerged as an effective technique for detecting wire breaks resulting from, e.g., stress corrosion cracking, and its application on prestressed concrete bridges is increasing. The success of this monitoring measure depends crucially on a carefully designed sensor layout. For this, the attenuation of elastic waves within the structure’s material is ideally determined in situ through object-related measurements (ORMs) with a reproducible signal source, typically a rebound hammer. This assumes that the attenuation coefficients derived from rebound hammer tests are comparable to those from wire breaks, thus allowing their results to be directly applied to wire break detection without further adjustments. This study challenges this assumption by analysing attenuation behaviour through an extensive dataset. Employing time-domain and frequency analysis, the research generates attenuation profiles from laboratory experiments and in situ measurements across various girders and bridge structures, extracting the slope and residual standard deviation (RSD). While generally validating this approach, the findings highlight differences in attenuation behaviour from among wire break signals and rebound hammer impulses, whereby the latter potentially underestimates the relevant attenuation of wire breaks by approximately 20%. Consequently, a transfer factor is proposed to adjust ORM results obtained with the rebound hammer for wire break scenarios. It consists of a scaling factor of 1.2 to modify the average attenuation coefficient and a constant term of ±1.0 dB/m to cover a 95% confidence interval, and thus, account for sample scattering. Moreover, the anisotropic attenuation behaviour across different structures was studied, showing that transverse attenuation consistently exceeds the longitudinal, significantly influenced by structural features such as voids. In prefabricated concrete bridges with in situ-cast concrete slabs, transverse signal transmission remains unhindered across multiple elements. Finally, the results provide a valuable reference for the design of sensor layouts in bridge monitoring, particularly benefiting scenarios where direct in situ experiences are lacking.
... Much of the current research on the characterisation of the acoustic properties of materials and acoustic characterisation of the materials themselves has been conducted at temperatures above 0 • C [11,12,13,14], with less emphasis on temperatures below 0 • C [15]. Additionally, existing studies of properties at low-temperature are spread across various fields, including seismology [16,17,18], glaciology [19,20], and the food industry [19,20,15]. ...
... For studies [7,12], which use a thin window made of glass or fused-quartz, we regard them as a thin film as well, where the exact thickness is not given. In studies [1,4,10,11,13], media thicker than a few millimetres were chosen. However, it is unclear whether the samples were in the near or far field (study index (1,11)). ...
... In studies [1,4,10,11,13], media thicker than a few millimetres were chosen. However, it is unclear whether the samples were in the near or far field (study index (1,11)). For instance, in study index (1), the last axial maximum is calculated to be at 3.62 cm using the frequency of 2.5 MHz and transducer diametre of 1.25 cm, and a longitudinal velocity in the plexiglas medium of 2700 m/s [70]. ...
Existing data on the acoustic properties of low-temperature biological materials is limited and widely dispersed across fields. This makes it difficult to employ this information in the development of ultrasound applications in the medical field, such as cryosurgery and rewarming of cryopreserved tissues. In this review, the low-temperature acoustic properties of biological materials, and the measurement methods used to acquire them were collected from a range of scientific fields. The measurements were reviewed from the acoustic set-up to thermal methodologies for samples preparation, temperature monitoring, and system insulation. The collected data contain the longitudinal and shear velocity, and attenuation coefficient of biological soft tissues and biologically relevant substances - water, aqueous solutions, and lipids - in the temperature range down to -50°C and in the frequency range from 108 kHz to 25 MHz. The Multiple-Reflection Method (MRM) was found to be the preferred method for low-temperature samples, with a buffer-rod inserted between the transducer and sample to avoid direct contact. Longitudinal velocity changes are observed through the phase transition zone, which is sharp in pure water, and occurs more slowly and at lower temperatures with added solutes. Lipids show longer transition zones with smaller sound velocity changes; with the longitudinal velocity changes observed during phase transition in tissues lying between these two extremes. More general conclusions on the shear velocity and attenuation coefficient at low-temperatures are restricted by the limited data. This review enhance knowledge guiding for further development of ultrasound applications in low-temperature biomedical fields, and may help to increase the precision and standardisation of low-temperature acoustic property measurements.
... Considering the acoustic attenuation in the fluid, the aim should be to minimise the fluid thickness while still fulfilling the condition above. The literature typically describes the frequency-dependent attenuation α by a power law [35,36]. For water, a quadratic dependence on frequency is commonly assumed [35,[37][38][39][40][41][42]. ...
... The literature typically describes the frequency-dependent attenuation α by a power law [35,36]. For water, a quadratic dependence on frequency is commonly assumed [35,[37][38][39][40][41][42]. ...
... The diffraction correction (Section 2.4.4) significantly reduces the increase at low frequencies and, thus, improves the result. No comparison was made between the measured sound speed and the literature data, as the literature data differ greatly due to the different alloys used (from 6200 m s to 6400 m s [35]). ...
Optoacoustics is a metrology widely used for material characterisation. In this study, a measurement setup for the selective determination of the frequency-resolved phase velocities and attenuations of longitudinal waves over a wide frequency range (3– 55MHz) is presented. The ultrasonic waves in this setup were excited by a pulsed laser within an absorption layer in the thermoelastic regime and directed through a layer of water onto a sample. The acoustic waves were detected using a self-built adaptive interferometer with a photorefractive crystal. The instrument transmits compression waves only, is low-contact, non-destructive, and has a sample-independent excitation. The limitations of the approach were studied both by simulation and experiments to determine how the frequency range and precision can be improved. It was shown that measurements are possible for all investigated materials (silicon, silicone, aluminium, and water) and that the relative error for the phase velocity is less than 0.2 .
... The attenuation coefficient α is generally defined as dB/m (the attenuation in decibel when ultrasonic waves propagate over a distance of one meter). In this analysis model, the value of α = 500 dB/m, which is based on general measurements at a frequency of 5 MHz [7], was applied. ...
An imaging technology using phased array ultrasonic testing (PAUT) was applied to bogie parts inspection, targeting welded members in bogie frames and wheel seats in axles. Regarding bogie frames, the superiority of PAUT was confirmed in detecting inclined surface flaws, and the influence of paint thickness on the flaw detection was clarified. When PAUT was applied to an actual bogie frame, the results of flaw detection were visualized clearly, demonstrating the effectiveness of PAUT in bogie frames. Regarding axles, when PAUT was applied to a wheel seat using shear-wave and longitudinal-wave angle-beam inspection techniques, flaws on the wheel seat were detected and visualized in a wheel-fitted state.
... In addition to the utility of UNDE, the present work is intended to motivate theoretical studies of ultrasonic attenuation in FRP laminates, despite the significant obstacles of properly accounting for fiber distributions, wave scattering, fiber-matrix mismatch, and interlaminar refraction. Such theoretical studies were scarce, as reviewed in [29][30][31]. ...
... This method produced complex stiffness tensors, and damping factors were found to be two to ten times those of isotropic polymethyl methacrylate (PMMA) [18,19]. These results were generally comparable to those from direct measurements using through-transmission methods [30,31]. However, the samples in these early studies [18,19,23] were only identified as carbon-fiber (or glassfiber)-reinforced composites, making it difficult for quantitative evaluation. ...
... Two recent studies [30,31] reported ultrasonic attenuation results for large numbers of engineering materials using through-transmission methods. Both longitudinal and transverse wave transmission modes were evaluated in nearly 300 samples. ...
Ultrasonic attenuation measurements were conducted on cross-ply and quasi-isotropic lay-ups of eight types of carbon-fiber reinforced composites (CFRPs) using through-transmission methods with diffraction correction. Attenuation values were substantially higher than those of unidirectional composites and other structural materials. Wave modes, fiber distributions, matrix resins, and consolidation methods affected total attenuation. Transverse mode, quasi-isotropic lay-up, and polyimide and thermoplastic resins generally produced higher attenuation. No clear trends from the fiber distribution were revealed, indicating that it is not feasible presently to predict the attenuation of various lay-ups from the unidirectional values. That is, direct attenuation tests for different laminate lay-ups are needed. This work expanded the existing attenuation database by properly determining the attenuation coefficients of two additional layup types of CFRP laminates. Results showed the merit of ultrasonic attenuation measurements for quality control and structural health monitoring applications. A crucial benefit of the through-transmission methods is that they enable the prediction of Lamb wave attenuation in combination with software like Disperse (ver. 2.0.20a, Imperial College, London, UK, 2013).
... reference voltage, and the coefficient β is ~1.125. We hence assume that marble does have an approximately linear frequency spectrum with low attenuation as observed in previous work (37,38). As a first approximation, we assume v p = 6 km/s and consider the variation of velocity to be trivial (for high confining pressure >100 MPa tests this variation is less than 10%). ...
... and v p = 6 km/s, the Rayleigh scattering regime falls in ≪ 60 MHz. As an approximation, when the wavelength is larger than three times the grain size ( ≫ 300 μm → ≪ 20 MHz ), the attenuation as a function of frequency evolves in the form of ω 2 (38). For higher frequencies, the attenuation due to scattering loss becomes independent of frequencies. ...
Deformation of all materials necessitates the collective propagation of various microscopic defects. On Earth, fracturing gives way to crystal-plastic deformation with increasing depth resulting in a “brittle-to-ductile” transition (BDT) region that is key for estimating the integrated strength of tectonic plates, constraining the earthquake cycle, and utilizing deep geothermal resources. Here, we show that the crossing of a BDT in marble during deformation experiments in the laboratory is accompanied by systematic increase in the frequency of acoustic emissions suggesting a profound change in the mean size and propagation velocity of the active defects. We further identify dominant classes of emitted waveforms using unsupervised learning methods and show that their relative activity systematically changes as the rocks cross the brittle–ductile transition. As pressure increases, long-period signals are suppressed and short-period signals become dominant. At higher pressures, signals frequently come in avalanche-like patterns. We propose that these classes of waveforms correlate with individual dominant defect types. Complex mixed-mode events indicate that interactions between the defects are common over the whole pressure range, in agreement with postmortem microstructural observations. Our measurements provide unique, real-time data of microscale dynamics over a broad range of pressures (10 to 200 MPa) and can inform micromechanical models for semi-brittle deformation.
... In this method, a multi-element device emits pulsating ultrasonic waves [20,21]. The processing of primary and secondary signal envelopes provides a high-resolution image of the damage [22][23][24]. ...
In recent years, the increase in energy prices and demand has been driven by the post-pandemic economic recovery. Of the various energy sources, oil and natural gas remain the most important source of energy production and consumption after coal. Oil and gas pipelines are a key component of the overall energy infrastructure, transporting oil and gas from mines to end users, so the reliability and safety of these pipelines is critical. The oil and gas industry incurs large expenses for the removal of failures related to, among others, corrosion of pipelines caused by the presence of Hg, CO2 H2S, carbonates and chlorides in reservoir waters. Therefore, pipeline operators must constantly monitor and prevent corrosion. Corrosion failure losses are a major motivation for the oil and gas industry to develop accurate monitoring models using non-destructive NDT methods based on test results and failure frequency observations. Observing the locations of frequent pipeline failures and monitoring and applying corrosion protection to pipelines play an important role in reducing failure rates and ultimately increasing the economic and safety performance of pipelines. Monitoring and prevention efforts support the decision-making process in the oil and gas industry by predicting failures and determining the timing of maintenance or replacement of corroded pipelines. We have presented methods of prevention through the use of corrosion inhibitors in crude oil and natural gas transmission pipelines, as well as various factors that influence their application. In this article, a review of corrosion rate monitoring systems is conducted, and a range of control and monitoring scenarios is proposed. This knowledge will aid scientists and practitioners in prioritizing their policies, not only to choose the appropriate monitoring technique but also to enhance corrosion protection effectiveness.
... Two different derivation methods confirmed the validity of Equation (1) or the Torikai-Roger-van Buren (TRvB) equation. This equation has been extensively used in ultrasonic attenuation studies [31][32][33][34][35]. Using the near-field distance, N = f a 2 /v, the Z parameter can be given as Z = z/N (i.e., the wave propagation distance in the unit of the near-field ...
... Experimental details of such tests are given in reference [52]. Attenuation correction of 1.5 dB was applied to the Al-7075 results using the attenuation data for this plate [33]. Their general trends agreed with the three calculated p(X,Z). ...
Ultrasonic non-destructive evaluation, which has been used widely, can detect and size critical flaws in structures. Advances in sound field calculations can further improve its effectiveness. Two calculation methods were used to characterize the relevant sound fields of an ultrasonic transducer and the results were applied to construct and evaluate Distance-Gain-Size (DGS) diagrams, which are useful in flaw sizing. Two published DGS diagrams were found to be deficient because the backward diffraction path was overly simplified and the third one included an arbitrary procedure. Newly constructed DGS diagrams exhibited transducer size dependence, revealing another deficiency in the existing DGS diagrams. However, the extent of the present calculations must be expanded to provide a catalog of DGS diagrams to cover a wide range of practical needs. Details of the new construction method are presented, incorporating two-way diffraction procedures.
... In these units, the (zero-temperature) shear modulus of the crystal G = 2, Young modulus E = 5, and Poisson ratio Fig. 1, using DPD damping, with scaling laws given by Eqs. (12) and (13). Note that panel (a) uses double-logarithmic scales. ...
... This would be the attenuation in a perfect crystalline sample, and with electron-phonon coupling being the only dissipation channel. The actually measured attenuation in real metals in the ultrasound regime is typically ∼ 100 dB/m [13], corresponding to an attenuation length of centimeters, i.e. significantly smaller. This shows that, in real metals, other mechanisms (besides electron-phonon coupling) also are at play, enhancing dissipation [14,15]. ...
... Analogue ofFig. 3, using DPD damping, with scaling laws given by Eqs.(12) and(13). ...
We study dissipation as a function of sample thickness in solids under global oscillatory shear applied to the top layer of the sample. Two types of damping mechanism are considered: Langevin and Dissipative Particle Dynamics (DPD). In the regime of low driving frequency, and under strain-controlled conditions, we observe that for Langevin damping, dissipation increases with sample thickness, while for DPD damping, it decreases. Under force-controlled conditions, dissipation increases with sample thickness for both damping schemes. These results can be physically understood by treating the solid as a one-dimensional harmonic chain in the quasi-static limit, for which explicit equations (scaling relations) describing dissipation as a function of chain length (sample thickness) are provided. The consequences of these results, in particular regarding the choice of damping scheme in computer simulations, are discussed.
