Ultrasonic Propagation Characteristics Research Articles

Ultrasound propagation characteristics within the bone tissue of miniature ultrasound probes: implications for the spinal navigation of pedicle screw placement.

The accuracy of pedicle screw fixation is crucial for patient safety. Traditional navigation methods based on computed tomography (CT) imaging have several limitations. Therefore, this study aimed to investigate the ultrasonic propagation characteristics of bone tissue and their relationship with CT imaging results, as well as the potential application of ultrasound navigation in pedicle screw fixation. The study used three bovine spine specimens (BSSs) and five human vertebral allograft bones (HABs) to progressively decrease the thickness of the cancellous bone layer, simulating the process of pedicle screw perforation. Five unfocused miniature ultrasound probes with frequencies of 2.2, 2.5, 3, 12, and 30 MHz were employed for investigating the ultrasonic propagation characteristics of cancellous and cortical bone through ultrasound transmission and backscatter experiments. The CT features of the bone tissue was obtained with the Skyscan 1174 micro-CT scanner (Bruker, Billerica, MA, USA). The experimental results demonstrated that low-frequency (2-3 MHz) ultrasound effectively penetrated the cancellous bone layer up to a depth of approximately 5 mm, with an attenuation coefficient below 10 dB/cm. Conversely, high-frequency (12 MHz) ultrasound exhibited significant signal attenuation in cancellous bone, reaching up to 55.8 dB/cm. The amplitude of the backscattered signal at the cancellous bone interface exhibited a negative correlation with the bone sample thickness (average r=-0.84), meaning that as the thickness of the cancellous bone layer on the cortical bone decreases, the backscattered signal amplitude gradually increases (P<0.05). Upon reaching the cortical bone interface, there was a rapid surge in echo signal amplitude, up to 8 times higher. Meanwhile, the statistical results indicated a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabecular structure. Theoretically, using multiple ultrasonic probes (≥3) and regions of interest (ROIs) (≥5) has the potential to provide surgeons with early warning signals for pedicle perforation based on three or more successive increases in echo signal amplitude or a sudden substantial increase. The statistical results indicate a significant correlation between the amplitude of the echo signal and the micro-CT scanning results of bone trabeculae, suggesting the potential use of ultrasound as opposed to CT for real-time intraoperative bone navigation.

Ultrasonic propagation characteristics and microstructure analysis of cement paste doped with cellulose ether

Ultrasonic propagation characteristics and microstructure analysis of cement paste doped with cellulose ether

Ultrasonic propagation characteristics of partial discharge in oil-impregnated paper traction transformer

Partial Discharges (PDs) are a significant factor in reducing the insulation life of traction transformers. In recent years, the Acoustic Emission (AE) method has become the most advanced method for detecting PD signals in transformers. The AE method utilizes AE sensors placed on the transformer tank to detect ultrasonic signals emitted by PD and determine the Time Of Arrival (TOA) of the head wave. The windings and cores of a traction transformer consist mainly of metal, which greatly affects the propagation of PD ultrasonic waves. This paper establishes a 110 kV “pressure acoustic, transient” physical field model of the traction transformer with dimensions of 4.63 × 1.48 × 2.84 m3. The model is used to carry out the PD pressure acoustic physical field simulation study of the traction transformer, to clarify the physical characteristics of the ultrasound of the PD defects, and to establish observation points on the transformer tanks to receive ultrasonic time-domain waveforms for PD detection. The simulation results indicate that PD ultrasonic waves exhibit complex propagation characteristics, including reflection, refraction, and reverberation, as they pass through the windings and cores to the observation points. The TOA of the head wave in the ultrasound time-domain waveform is indicated by the first maximum value of the wave crest line. Finally, this paper proposes a multi-level localization method based on the AE method to determine which winding generates the PD in the large-scale traction transformer using only four dynamically moving observation points.

Gas-insulated switchgear partial discharge acoustic–electric joint localisation method based on the Salp Swarm Algorithm and least squares estimation

Partial discharge (PD) is an early warning of gas-insulated switchgear (GIS) insulation faults. Consequently, accurate localisation of PD is crucial for the safe operation of GIS. The time difference of arrival method based on acoustic emission technology is more favorable for the engineering application of PD source localisation owing to its noninvasive characteristics and the small amount of required data. However, because PD ultrasonic signal propagation in GIS will introduce a variety of errors, current localisation algorithms suffer from problems of low accuracy and poor stability. Therefore, this study simulate and analyse the ultrasonic propagation characteristics as well as the sources of errors in GIS, based on which a joint acoustic–electric localisation method based on the Salp Swarm Algorithm is proposed, and an error-correction method based on least squares estimation is introduced. The localisation results show that the proposed method can effectively reduce the localisation error caused by multiple sources of error, and the mean localisation error can be reduced to within 20 mm in different structural gas chambers of GIS, which is more accurate and more stable compared with other methods, and it has good value for engineering application.

Micromechanics and Ultrasonic Propagation in Consolidated Earthen-Site Soils.

Although nondestructive ultrasonic technologies have been applied in laboratory and field tests in the field of heritage conservation, few studies have quantified the relationship among the real microstructures, micromechanical properties, and macroscopic acoustic responses of earthen-site soils. This paper develops a micromechanics-based multiscale model for quantitatively exploring the ultrasonic propagation characteristics of elastic waves in untreated and consolidated earthen-site soils. Scanning electron microscope images and image processing technology are integrated into the finite-element simulation. The effects of microstructure and wave features on the acoustic characteristics of soils are quantitatively investigated under pulsive loading. The simulation results of untreated and consolidated soils are efficiently compared to ultrasonic test data. It is demonstrated that the integration of microstructure image processing and multiscale modeling can predict the ultrasonic pulse velocity well, which improves the accuracy of laboratory testing and field monitoring and better serves the evaluation and implementation of engineering practice in the field of heritage conservation.

A modified synthetic aperture focusing algorithm used for transmission detection based on laser ultrasonics method

Compared with traditional ultrasonic nondestructive testing technology, the laser ultrasonics method (LU) has the advantages of high precision, non-contact, wide-band response, suitable for non-destructive testing (NDT) of materials having complex shapes or working in extreme environments such as the additive manufacturing (AM) process, etc. However, for a purely optical LU system, it is still limited by the poor reflection of rough/absorption surface of the material. In order to increase the signal-to-noise ratio (SNR) of the signal detected on the rough surface of a sample, and to overcome the limitation of the resolution restricted by half wavelength, a modified Synthetic Aperture Focusing Technique (SAFT) that can be used for internal defect detection of the material is proposed. The modified SAFT is based on LU centering transmission detection and it improves the resolution of the detection system by using the characteristics of ultrasonic propagation and its mode conversion. It is firstly studied in theory with a numerical model based on finite element method (FEM), and then it is applied in experiments to reconstruct the defect according to the signals detected by LU method. In our experiment, the artificial defects buried in an AM sample with diameter from 0.2 mm to 0.75 mm are successfully characterized by the SAFT imaging of ultrasonic signals. The results prove that the position of the defect in 3D and its size can be successfully obtained by the proposed SAFT.

Numerical simulation of ultrasonic velocity in wet steam

Wet steam widely exists in thermal power plants, nuclear power plants and other power engineering. The accurate measurement of steam wetness is very important for the safety and economy of power engineering. Ultrasonic method is feasible to measure the concentration of two-phase flow in particle system. In order to obtain a theoretical model of ultrasonic velocity which can be applied to high flow velocity conditions (Reynolds number > 4000), the numerical results of several ultrasonic propagation characteristics theoretical models are compared with the experimental results. The calculated results of U-A coupled phase model show good agreement with the experimental results (the max error is 3.8%), and the model is more suitable for the numerical calculation of ultrasonic sound velocity in droplet two- phase flow with high flow velocity. The ultrasonic sound velocity of steam system in nuclear power plant is calculated numerically. When the droplet size is less than 8 μm, the sound velocity is sensitive to the variation of the droplet size, and when the droplet size is larger than 8 μm, the sound velocity is almost unaffected (velocity variation <0.5%) by the fluctuation of the droplet size. When the effect of the droplet size change on sound velocity can be ignored, the ultrasonic sound velocity method combined with U-A coupled phase model can be used to measure the steam wetness online.

Study on Ultrasonic Propagation Characteristics of Partial Discharge in 10 kV XLPE Cable

Study on Ultrasonic Propagation Characteristics of Partial Discharge in 10 kV XLPE Cable

Research on laser ultrasonic propagation characteristics and quantitative detection of delamination of carbon fiber composite

Aiming at the problems of low signal-to-noise ratio (SNR) and low detection accuracy in the non-destructive testing of composites with anisotropic and multilayer structure, the delamination detection of composite materials is studied by using the advantages of laser ultrasonic micro defect detection combined with phased array technology. Firstly, through finite element simulation, the propagation characteristics of laser ultrasound when the delamination evolves are obtained, and a time-modulated phased array laser ultrasound test platform is designed to improve the SNR and detection efficiency of the delamination signal. Then, a laser ultrasonic feature extraction method based on the improved Hilbert-Huang transform is proposed. It includes optimizing the decomposition process of CEEMDAN (Complete Ensemble Empirical Mode Decomposition with Adaptive Noise), searching for the sensitive IMF components through correlation coefficient between the decomposed signal and the original signal, and extracting the feature parameters by Hilbert transform. Finally, the maximum amplitude imaging of the delamination defects is performed using the extracted feature parameters. Experiments show that the proposed method can characterize the delamination characteristics with high accuracy, effectively solve the interference of resin layer on the delamination characteristic signal, and can visualize the delamination in composites.

Complex measurement of parameters of iron ore magnetic separation based on ultrasonic methods

Purpose. To develop a method for complex ultrasonic measurement of such parameters of the iron ore slurry flow passing through the working chamber of the magnetic separator as efficiency, concentration and grade size distribution of solid-phase particles. Methodology. The research uses methods of modelling processes of ultrasonic wave propagation in the iron ore slurry. Ultrasonic wave absorption and scattering in water with solid particles and air bubbles are considered. To characterize absorption and scattering of acoustic oscillations by oscillating gas bubbles, concepts of effective cross-sections of attenuation, absorption and scattering are introduced. Findings. The dependence of the phase velocity of asymmetric Lamb waves on the wall thickness of the magnetic separator was obtained. As a result of computer simulation of the process of ultrasonic waves propagation, its time and frequency characteristics were obtained. Based on the data obtained using ultrasonic measurements, the coefficients of the Rozin-Rammler equation for the characteristics of the ore material at various points of the technological line were calculated. Originality. The proposed method of ultrasonic measurement of characteristics of the iron ore slurry in the working chamber of the magnetic separator differs from the existing ones in the fact that the Lamb wave source operates in a wide pattern and is connected by a V-shaped scheme which makes it possible to create a beam of coherent waves propagating both in the container wall (the working separator chamber) and in the measured medium (the iron ore slurry). Practical value. The practical value consists in developing an ultrasonic measuring channel scheme for determining characteristics of the iron ore slurry in the working chamber of the magnetic separator.

직선형 파동유도관에서 벽면에 따른 초음파 전파

This study deals with the ultrasonic propagation characteristics according to the wall in a linear waveguide combined with an ultrasonic sensor for distance measurement. The purpose is to reduce the wall reflection by a rough surface because the wave reflecting on a smooth wall of the waveguide would interfere with straightly travelling wave. Wedges were designed on the waveguide wall. Ultrasonic wave propagation in a linear waveguide with the wedged wall was analyzed by finite elements, and the magnitude of the wave signals was evaluated according to the wedge angle for distance measurement. Experiments were carried out and the analysis results were verified by comparison. Wedge angle maximizing the wave signal magnitude was obtained.

Ultrasonic Propagation Characteristics of FRP Plates with Cure Distribution in the thickness direction

Ultrasonic Propagation Characteristics of FRP Plates with Cure Distribution in the thickness direction

Automatic Positioning and Recognition of Anesthesia Points Based on Ultrasound Image Guidance Technology

Local anesthesia has certain harm to the patient, and the wrong position of the anesthesia point may result in poor anesthesia effect. Based on this, this study built an automatic positioning recognition model based on ultrasound image guidance technology. At the same time, this paper combined the actual requirements of anesthesia to establish a wireless positioning system based on ultrasonic infrared, and the system combined ultrasonic propagation characteristics and sensing receiving characteristics. In addition, in the study, this article combined with the state of the anesthesia point to take ultrasound-guided anesthesia. Finally, this paper designed a comparative experiment to study the performance of automatic positioning of anesthesia points based on ultrasound image guidance technology and collected actual data to analyze. Studies have shown that the method proposed in this study has certain clinical effects and can provide theoretical references for subsequent related research.

Ultrasonic wave propagation characteristics for typical anisotropic failure modes of shale under uniaxial compression and real-time ultrasonic experiments

AbstractUniaxial loading and real-time ultrasonic experiments on shales were conducted to study the progressive failure of shale and the ultrasonic propagation characteristics during loading. The results show that the variations in P-wave and S-wave velocities with stress correspond to the crack damage process for the typical anisotropic failure of shale, and that the S-wave amplitude is sensitive to the damage that arises in shale during loading. If the bedding participates relatively simply in the failure (0° and 60° inclinations), the spectrum and the main frequency shape are simple and remain basically unchanged during loading. In the cases where the failure mode is complicated by the participation of the bedding and the matrix (30° and 90° inclinations), the spectrum and the main frequency shape are complex and change dynamically with loading. These results indicate that ultrasonic dynamic parameters reflect the differences in the failure of shale.

Random multi-phase medium model and its application in analysis of ultrasonic propagation characteristics for AlSi-polyester abradable seal coating

Ultrasonic nondestructive characterization of multi-phase heterogeneous coatings is challenging due to the complex elastic spatial distribution. In this paper, a two-dimensional Random Multi-phase Medium Model (RMMM) for heterogeneous coatings containing solid-solid-gas three phases is developed, which is able to simulate the elastic spatial distribution of coatings by taking into account material microstructure. This model is then applied to correlate ultrasonic wave velocity and attenuation coefficient with component contents and microstructural characteristics. Microscopic observations were performed for AlSi-polyester abradable seal coatings to examine the morphology and content of AlSi, polyester, and pore. Further statistical analysis of the autocorrelation lengths, orientation angle, mean value, standard deviation, and roughness factor of the coating density distributions was carried out. These statistical characteristics provided quantitative constraints on the construction of a random medium, which were then taken as the basis to establish the RMMM by virtue of a bidirectional peak-valley searching algorithm. The RMMMs for AlSi-polyester abradable seal coating with a thickness of 1.0 mm, polyester content of 47.6%–44.1%, porosity of 0.3%–4.0% were presented. Based on these RMMMs, the effects of component contents, sizes, and spatial distributions on velocity and attenuation were analyzed using two-dimensional Finite-Difference Time-Domain (2D-FDTD) method. Results indicate that when porosity increases from 0.3% to 4.0%, the longitudinal wave velocity decreases from 2251 m/s to 2150 m/s whose relative variation ratio is about 4.5%, while the attenuation coefficient increases from 4.45 dB/mm to 6.56 dB/mm whose relative variation ratio is up to 47.4%. The simulated results show a good consistency with those of the experiments. The modeling method is expected to be effective for the precise interpretation of ultrasonic propagation in other multi-phase heterogeneous coatings.

Effect of Cross-slot Defect in welded joint on Ultrasonic Test

This paper focuses on the influence of vertical hole defects on the ultrasonic propagation characteristics, which are studied from two aspects of the propagation characteristics of the base metal and the ultrasonic waves of the weld, respectively. The acoustic reflection characteristics of the reflector are compared with the acoustic reflection characteristics of the two different welding processes, manual welding and automatic welding, and the properties of the base material. It is shown that the cross-slot of the weld is different from the cross-slot in the base metal, and the attenuation of the ultrasonic wave in the base metal and the weld is different. The gain compensation is too large, and the automatic welding gain compensation ratio of the upper groove of the weld is lower. The automatic welding gain compensation of the cross-slot is large, and the manual welding gain compensation of the lower cross-slot is higher than that of the automatic welding, and the cross-slot gain compensation of the automatic welding upper surface weld is higher than that of the manual welding.

Influence of Vertical Hole Defects on Ultrasonic Test

9Ni steel has good toughness and high strength. This paper focuses on the influence of vertical hole defects on the ultrasonic propagation characteristics, which are studied from two aspects of the propagation characteristics of the base metal and the ultrasonic waves of the weld, respectively. The acoustic reflection characteristics of the reflector are compared with the acoustic reflection characteristics of the two different welding processes, (manual welding and automatic welding). It is shown that the gain compensation of the weld is larger than the gain of the same diameter and the same position of the vertical hole in the base metal. The gain compensation of the automatic welding is larger than that of the manual welding. The ultrasonic attenuation in the automatic welding is larger than that of the manual welding. The results of the study contribute to improving the application of ultrasonic testing in 9Ni weld joints.

Ultrasonic Computerized Tomography Imaging Method With Combinatorial Optimization Algorithm for Concrete Pile Foundation

Concrete pile foundations are the main load-carrying and aseismic structures for many large-scale building structures. Their structural quality will have a great impact on the safety of building structures. However, the imaging results still cannot easily meet practical demands in current ultrasonic Computerized Tomography (CT) imaging tests of concrete structures. In view of the current difficulties, a combinatorial optimization tomographic imaging method is proposed. First, a quadric broadening objective function with a clear physical meaning is established according to the characteristics of ultrasonic propagation in concrete. Then, a new CT imaging method of concrete pile foundation is formed by combining fast adaptive optimization search ability of Genetic Algorithm (GA) with the global search control ability of Simulated Annealing Algorithm (SAA). The numerical simulation experiments have shown that the usage of the correct priori information and the excellent characteristic of the Simulated Annealing Genetic Algorithm (SAGA) in searching for the global minimum value of the function have produced accurate and effective results with stable numerical values. Finally, the imaging method is verified by experiment, where results show that SAGA requires fewer iterations, has faster computation speed and gives more accurate imaging results compared with the single GA.

Ultrasonic propagation characteristics in MR fluid under magnetic fields

Ultrasonic propagation characteristics in MR fluid under magnetic fields

Simulation analysis of ultrasonic detection for resistance spot welding based on COMSOL Multiphysics

The simulated calculation is carried out on the ultrasonic detection process for stainless steel resistance spot welding by the finite element technology. It reveals the ultrasonic propagation characteristics and regularity in the inner of the spot welds, and provides a theoretical basis for selecting the Am as a characteristic parameter to represent the fusion state of the spot weld in the actual ultrasonic detection. Then the ultrasonic detection of spot welds with the presence of the porosity defect which easily appears is simulated, and the effect of the porosity on the ultrasonic propagation characteristics is studied. It is found that the ultrasonic reflection and transmission occur at the porosity defect, and finally the correctness and validity of the simulation and the model are verified by the experimental method.