Ultrasonic 3D Research Articles

Hybrid physics machine learning for ultrasonic field guided 3D generation and reconstruction of rail defects

Ultrasonic technology is widely used in the field of rail defects detection. 3D reconstruction of rail defects can intuitively restore the 3D size and spatial position of the defects inside the rail. Currently, ultrasound-based 3D reconstruction requires a multi-probe or mechanical scanning platform in a laboratory setting, which is not suitable for the railway environment. In addition, 3D reconstruction requires a large amount of data, making it difficult to collect sufficient ultrasonic 3D defect data for long-distance rail inspections. This paper proposes an ultrasonic field-guided 3D reconstruction method combined with machine learning hybrid physics for rail defects. It combines both sound field GAN model to reconstruct the defect 3D model from the 2D B-scan data. The proposed method can generate a defect cross-sectional image using a deep learning algorithm guided by the acoustic field in the B-scan space, and extract the 3D size information of the defect from the 2D B-scan information by establish a defect echo model. By stablishing a spatial mapping relationship between the B-scan and the rail coordinate system, the position of the defect in the rail coordinate system is obtained. The defect data of standard damage rails are tested. Experiment results indicate that the defects in different parts of the rail can be reconstructed by the proposed method. The average size error rate is 9.56%–21.14 %, and the average height error is 3.458mm–6.353 mm.

Effect of rubber granules and rubber threads on mechanical properties of cement-bound base course

The study investigates the application of waste rubber in cement-stabilized base course (CBC), aiming to address internal stresses, reflective cracks, and waste disposal issues. Mixtures of gravel and sand stabilized with varying cement and rubber content were examined, including reference mixtures and those with granulated rubber or rubber threads, a total of 17 mixtures. Mechanical properties, durability, and environmental impact were evaluated through standard tests such as Proctor elements, compressive and tensile strengths, freezethaw resistance, shrinkage, and scanning electron microscope analysis. Non-standard, non-contact methods like ultrasonic pulse velocity and 3D digital image correlation were employed. Results indicate the feasibility of using waste rubber in CBC, with the optimal mixture containing 5 % cement and 20 % rubber as a replacement for sand showing satisfactory compressive strength (3.01 MPa) for application as a base layer, reduced stiffness, improved frost resistance (9.76 %), improved tensile to compressive strength ratio (52.99 %), and increased resistance to reflective cracking comparing to reference mixture. Moreover, it exhibited minimal shrinkage compared to other mixtures. The study underscores the importance of assessing environmental acceptability in waste materials for road construction, emphasizing the need for further research. Furthermore, the possibility of employing non-contact testing methods has been demonstrated.

Mechanical properties enhancement of 3D-printed HA-PLA composites using ultrasonic vibration assistance

ABSTRACT 3D-printed HA-PLA composites have attracted much attention because of their excellent biodegradability and osteointegration properties. However, HA particles negatively affect the mechanical properties of the composite parts. In this study, ultrasonic vibration-assisted 3D printing was used to improve the mechanical properties of HA-PLA composite specimens, and the effects of different infill angles and ultrasonic vibration power on the mechanical properties were investigated. The results demonstrated that the degradation and anisotropy of the mechanical properties of HA-PLA composites were alleviated by the use of ultrasonic vibration. By applying the ultrasonic vibration, the tensile and flexural strengths of the 20 wt% HA-PLA specimens fabricated with a 90° infill angle demonstrated the largest improvement of 104.3% and 112.7%, respectively. The high-frequency ultrasonic vibration waves promoted the spreading and fusion of the extruded materials, thereby reducing overlapping voids within the specimens and improving the interface bonding strength, also facilitated the refinement and dispersibility of the HA particles, which inhibited the formation of stress concentrations within the specimens and ultimately improved the mechanical properties. The printing process developed in this study can also be adapted to other particle (or other reinforcement types) reinforced composite to improve their mechanical performance.

Fabrication of a 3D structure MnO2 electrode with high MnO2 mass loading as the cathode for high-performance aqueous zinc-ion batteries

Benefiting from the remarkable advantages (eco-friendly, cost-effective, and high safety) of rechargeable aqueous zinc-ion batteries (AZIBs), AZIBs are regarded as viable alternatives to traditional Lithium-ion batteries (LIBs). However, in prevailing research, the excellent electrochemical performance usually achieved by ultra-low active material loadings (e.g., <1 mg/cm²), which is far from the active material mass loading of commercial electrodes in practical (≥10 mg/cm²). Balancing superior properties with high mass loading has posed a challenge. To surmount this, an innovative method combined ultrasonic processing, freeze-drying, and 3D printing technologies is used to engineer a high MnO2 mass loading cathode for AZIBs (3D cathode). Notably, the grid structure of 3D cathode substantially augmenting the surface area for redox reactions during charge/discharge processes, which greatly enhanced the pseudo-capacitance process of cathode. Additionally, the uniform and stable microstructure exhibited the dual capability of expediting ion/electron transfer and sustaining the structural integrity throughout charge/discharge cycles. Consequently, the 3D cathode demonstrated superior comprehensive electrochemical properties at the MnO2 high mass loading of 10 mg/cm2 (138.7 mAh/g at 1 A/g, 87.4 mAh/g after 500 cycles, 82 % energy efficiency) and 15 mg/cm2 (113.3 mAh/g at 1 A/g, 56.3 mAh/g after 400 cycles, 81 % energy efficiency).

Quantifying flow and velocity distributions in open channels with varied roughness and slopes: a modelling approach

ABSTRACT Understanding flow and velocity distributions in open channels is important for designing various hydraulic structures. This study focuses on modeling the flow and velocity distributions along with different open channel roughness (steel and concrete) and slopes from 0.0–4.7%, using an ultrasonic flowmeter and 3D scanner. Comprehensive Kriging and Linear Regression Models were developed to simulate flow behavior, considering the effects of surface roughness and channel slope. The models utilized appropriate boundary conditions by varying the roughness values. The concrete channel had an average centreline flow and velocity of 0.21 m3/s and 0.64 m/s, respectively, while the average flow and velocity for the steel channel was 0.33 m3/s and 0.97 m/s, respectively. The model’s accuracy and reliability were assessed by Pearson correlation and standard error of the estimate (SEE). According to the Pearson correlation, there is a significant relationship between the slope and flow on steel and concrete, with an average r equal to 0.75. The standard error of the estimates between observed and measured velocity and flow were 0.164 and 0.001, respectively.

A Multifunctional Acoustic Tweezer for Heterogenous Assembloids Patterning

Acoustic tweezers, capable of complicated manipulation of bioparticles by acoustic radiation forces using a noninvasive and noncontact approach, are an innovative technology for patterning assemble organoids. Hence, acoustic tweezers exhibit considerable potential for forming programmable patterning of organoids with specific spatial structures. Furthermore, heterogeneous assembloids with complex arrangement patterns can be built through sequential assembling and culturing to explore polarized tissue development or disease metastasis in multiple organs. This study focuses on the structural assembly of organoids using an ultrasonic 2D matrix array to generate real‐time switching of different acoustic fields. In addition, a local renal injured assembloid is fabricated to study and verify its application in tissue engineering and disease modeling.

Quasi-flat high-index acoustic lens for 3D underwater ultrasound focusing

We report a quasi-flat and sub-wavelength acoustic lens built using a soft matter process for broadband ultrasonic 3D focusing in water. By using a simple emulsion templating method, a soft porous material with a high acoustic index relative to water (∼5) has been molded and shaped into a convergent lens with a very low curvature and a thickness smaller than the working wavelength in water. This kind of acoustic metasurface generates a narrow focused beam, and its focal length can be adjusted. These acoustic lenses may be of great interest for underwater applications, where acoustic focusing and imaging are highly demanded.

An Experimental and Theoretical Comparison of 3D Models for Ultrasonic Non-Destructive Testing of Cracks: Part I, Embedded Cracks

Ultrasonic Non-Destructive Testing (NDT) methods are broadly used for detection and characterization/imaging of cracks. Simulation is of great interest for designing such NDT methods. To model the ultrasonic 3D response of a crack, ultrasonic high frequency asymptotic (semi-analytical) models (such as the Physical Theory of Diffraction—PTD) are known to provide accurate predictions for most classical NDT configurations, and 3D numerical models have also emerged more recently. The aim of this paper is to carry out for the first time an experimental and theoretical comparison of 3D models for ultrasonic NDT of embedded cracks in 3D configurations. Semi-analytical models and a hybrid 3D FEM strategy—combining high-order spectral Finite Elements Method (FEM) for flaw scattering and an asymptotic ray model for beam propagation—have been compared. Both numerical validations and comparisons between simulation and experiments prove the effectiveness of PTD in numerous configurations but validate and demonstrate the improvement provided by the 3D hybrid code, notably for small flaws compared to the wavelength and for shear waves.

Evolution Behavior and Closure Mechanism of Porosity in Large Billet during the Reduction Pretreatment

The reduction pretreatment process was proposed to be applied to large billets for the purpose of alleviating the center porosities and reducing the rolling ratio. This study focused on the evolution behavior and closure mechanism of porosity in a large billet during reduction pretreatment. The porosities were characterized by ultrasonic scanning and 3D reconstruction. The results showed that the porosities near the surface of the billet were firstly closed during the reduction pretreatment. The reduction began to effectively act on the center of the billet at the deformation of 0.16. When the reduction amount increased to 0.20–0.22, both the pore number and the porosity degree at the center of the billet were the smallest. As the deformation exceeded 0.25, the porosities gathered at the center of the billet, which may have caused larger defects. A numerical model for the reduction pretreatment was established to analyze the evolution behavior of porosity. The simulation results showed that the position with the maximum of strain moved toward the center of the billet as the reduction amount increased. At the position where the deformation was 0.20, the deformation would readily occur at the center, and the center strain was almost twice as much as the surface strain. The upper and lower surfaces of porosity were compressed to the center of the porosity in the thickness direction. The two ends of porosity were not stretched in the rolling direction. The closure index indicated that the deformation penetrated into the center would accelerate the deformation of porosity. The cross-sectional area of the porosity gradually decreased with the increase in the hydrostatic integration, which indicated that the hydrostatic integration could be used to assess the closure degree of porosity during the reduction pretreatment process. Both the closure index and the hydrostatic integration proved the effective role of the reduction pretreatment in the alleviation of porosity.

Full Characterization of in vivo Muscle as an Elastic, Incompressible, Transversely Isotropic Material Using Ultrasonic Rotational 3D Shear Wave Elasticity Imaging.

Using a 3D rotational shear wave elasticity imaging (SWEI) setup, 3D shear wave data were acquired in the vastus lateralis of a healthy volunteer. The innate tilt between the transducer face and the muscle fibers results in the excitation of multiple shear wave modes, allowing for more complete characterization of muscle as an elastic, incompressible, transversely isotropic (ITI) material. The ability to measure both the shear vertical (SV) and shear horizontal (SH) wave speed allows for measurement of three independent parameters needed for full ITI material characterization: the longitudinal shear modulus μL , the transverse shear modulus μT , and the tensile anisotropy χE . Herein we develop and validate methodology to estimate these parameters and measure them in vivo, with μL = 5.77±1.00 kPa, μT = 1.93±0.41 kPa (giving shear anisotropy χμ = 2.11±0.92 ), and χE = 4.67±1.40 in a relaxed vastus lateralis muscle. We also demonstrate that 3D SWEI can be used to more accurately characterize muscle mechanical properties as compared to 2D SWEI.

Environment Mapping Using Sensor Fusion of 2D Laser Scanner and 3D Ultrasonic Sensor for a Real Mobile Robot.

Mapping the environment is necessary for navigation, planning and manipulation. In this paper, a fusion framework (as data-in-decision-out) is introduced for a 2D LIDAR and a 3D ultrasonic sensor to achieve three-dimensional mapping without expensive 3D LiDAR scanner or visual processing. Two sensor models are proposed for the two sensors used for map updating. Furthermore, 2D/3D map representations are discussed for our fusion approach. We also compare different probabilistic fusion methods and discuss criterias for choosing appropriate methods. Experiments are carried out with a real ground robot platform in an indoor environment. The 2D and 3D map results demonstrate that our approach is able to show the surrounding in more details. Sensor fusion provides a better estimation of the environment and the ego-pose whilst lowering the necessary resources. This gives the robot’s perception of the environment more information by using only one additional low-cost 3D ultrasonic sensor. This is especially important for robust and light-weight robots with limited resources.

Application of Enhanced Whale Adaptive Threshold Noise Reduction Method in Transformer Ultrasonic 3D Imaging Detection

Most of the detection methods for transformer winding faults are off-line detection, which have to know the internal parameters of the transformer including the winding radius and the position of the winding center point It is only suitable for radial deformation, which has great limitations. Therefore, based on the principle of the ultrasonic wave propagation character, this paper designs a vertical 3D imaging detection system, which can visually display the 3D pattern of the winding deformation. This system can quantitatively and qualitatively detect the transformer and is suitable for various shapes of transformer winding deformation. An improved whale adaptive threshold optimization noisee reduction algorithm has been improved in this paper based on wavelet decomposition for the problem that echo is easily interfered by noise in ultrasonic detection. After testing, most of the interference noise can be filtered, so that the transformer can be more intuitive around the three-dimensional state diagram, which can better distinguish the fault location.

A Three-Dimensional Pen-Like Ultrasonic Positioning System Based on Quasi-Spherical PVDF Ultrasonic Transmitter

In this article, a three-dimensional (3D) pen-like positioning system based on the high-precision 3D ultrasonic (US) positioning method is presented. The high-precision 3D US positioning method can achieve millimeter-level accuracy in 3D positioning within a working area of 2 m $\times1.5$ m $\times1.5$ m. In order to improve the real-time performance of the proposed system, the 3D positioning of an electronic pen is realized by a high-precision time-of-flight (TOF) detection method based on the dynamic threshold and average zero-crossing detection. The average zero-crossing detection overcomes the limitations of the traditional zero-crossing detection that is sensitive to noise. The proposed positioning method can achieve high positioning accuracy without conducting complex calculations. The positioning accuracy of the proposed system is verified experimentally. In the experiment, a total of 60 test positions were uniformly set within the workspace, and static and dynamic positioning accuracy experiments were performed at all test positions. Experimental results showed that the static and dynamic positioning errors were less than 0.32 mm and 1.0 mm, respectively; thus, high positioning accuracy was achieved. In addition, the experimental results showed that the proposed systems could support 3D air writing. Accordingly, the proposed system can meet the crucial requirements of 3D human-computer interaction applications.

Anti-aliasing method for ultrasonic 2D phase-sensitive motion estimator

A 2D motion estimator can estimate tissue motions and blood flow dynamics more accurately than a 1D motion estimator. In this study, we proposed a simple anti-aliasing filter to unwrap the phase of the cross spectrum. The proposed method is evaluated by simulation mimicking steady flows, and the magnitude of the true velocity was changed from 200 to 2400 mm s−1. In the simulation, bias error was improved from 295.0% to 4.9% by the proposed method at a true velocity magnitude of 1600 mm s−1. Also, in the in vivo measurement of the left ventricle, the wrapping in the phase of the cross spectrum was corrected by the proposed method, and the directions of the blood velocity vectors were estimated more accurately.

Topological ordered copper graphene composite foam: Fabrication and compression properties study

Abstract The study presents a rapid manufacturing approach to fabricate a new class of topological ordered copper graphene foams (TOCGF) using combination of ultrasonic assisted pressureless sintering and 3D printing. The ultrasonic vibrations homogenously well dispersed the low-density graphene in the metal matrix. The relative density of the TOCGF was decreased with respect to pure copper with increasing the concentration of graphene. The compressive properties of the TOCGF were enhanced up to 1% graphene addition but decreased with further addition.

Uniform and graded copper open cell ordered foams fabricated by rapid manufacturing: surface morphology, mechanical properties and energy absorption capacity

Pure copper open cell ordered foams (COCOF) have tremendous applications in the field of thermal mechanical management systems. These foams possess high thermal and electrical conductivity, sufficient mechanical strength and energy absorption capacity because of copper as the parent material. In the present study, the combination of ultrasonic assisted pressureless sintering and 3D printing as a rapid manufacturing technique has been used to fabricate COCOF. Two different unit cell designs, Simple Cubic (SC) and Body-Centered Cubic (BCC) were selected to fabricate uniform foams of three strut sizes 1, 1.3 and 1.6 mm and graded foams with strut size varying from 1 to 1.6 mm. The dimensional deviations of the fabricated COCOF samples from the designed CAD model were found to be less, as compared to the traditional metal printing technique i.e. electron beam melting (EBM). Significant effect on the surface roughness was noticed due to post processing on the fabricated COCOF. The SC and BCC fabricated by COCOF possessed 19-160 MPa Young's modulus, 2.5-25 MPa compressive strength, 2.5-30 MPa plateau stress and 1.2-9.3 MJ/m3 energy absorption capacity. Moreover, the compression deformation behavior of these foams was investigated and found to be in-line with Ashby-Gibson model. However, due to micro-pores in fabricated COCOF, the struts were observed to be crushed during compression. The graded foam, with similar relative density, outperformed the uniform foam in terms of mechanical and energy absorption capacity for both SC and BCC COCOF. Moreover, the present method can be used to fabricate complex multi-functional thermal mechanical monolithic heat exchanger devices.

Development of high‐frequency‐type MEMS ultrasonic array sensor using P(VDF/TrFE) thin films

AbstractMEMS (microelectromechanical systems) ultrasonic array sensors were fabricated using the poly (vinylidene fluoride‐trifluoroethylene) [P(VDF/TrFE)] copolymer thin films having multilayer diaphragm structures. For an increased resonant frequency of sensor, we developed a new diaphragm structure. The resonant frequency and sensitivity of new MEMS ultrasonic array sensor was estimated to be on the order of 376 kHz and −75 dBV (1V/Pa = 0 dBV), respectively. This MEMS ultrasonic array sensor can be adapted for ultrasonic 3D imaging and nondestructive ultrasonic testing systems.

Rapid manufacturing of copper components using 3D printing and ultrasonic assisted pressureless sintering: Experimental investigations and process optimization

The present work deals with the comprehensive study of ultrasonic and sintering parameters effect on the rapid manufacturing of pure copper components by ultrasonic assisted pressureless sintering and 3D printing. The customized sintering setup with the stepped horn was designed and fabricated for the experiments. First, the ultrasonic assisted sintering process was compared to conventional pressureless sintering process in regards of physical and mechanical properties of fabricated samples. The study revealed that the ultrasonic vibrations increased the contact area between the particles and raised the local heating for large sintering necks. Thus, the ultrasonic assistance enhanced the properties of the fabricated parts. Further, response surface methodology was used to design the set of experiments with sintering temperature, heating rate, soaking time and ultrasonic power percentage intensity to study the parameters effect. The analysis of variance was performed to analyze the significant contribution of parameters on relative density, compressive yield strength, and volumetric shrinkage. The sintering temperature and ultrasonic power percentage intensity dominated the other parameters with respect to responses. The less effect of low ultrasonic power intensity and short soaking time at high sintering temperatures was revealed by the significant interactions. Furthermore, the genetic algorithm based multi-objective optimization was used for the parameters optimization on maximizing relative density, compressive yield strength and minimizing the volumetric shrinkage. The efficacy of the developed method was tested by the fabrication of a customized heat sink on the optimized parameters.

Characterization of air velocities near greenhouse internal mobile screens using 3D sonic anemometry

In Dutch greenhouses, different screen types are used for different purposes (shading, energy saving, black-out, light emission, etc.). In order to quantify the energy and mass transfers through screens, characterization of air permeability through the screens is required. In the case of energy-saving screens, it is an essential parameter to estimate the energy saving of each screen. Air permeability can be measured under defined conditions in a laboratory. In order to select the appropriate equipment for air velocity measurements, the air velocity vector near screens in a practical situation in a greenhouse needs to be identified by measurements. Sonic anemometry techniques have been used extensively in different types of greenhouses: a) to study natural ventilation, with and without insect screens, and in different positions; b) to study airflow patterns in greenhouses with mechanical ventilation/pad and fan systems; c) to study airflow patterns induced by different types of heating systems, and d) for the estimation of crop evapotranspiration (i.e., eddy covariance). However, to the best of our knowledge, no research has been carried out to study the airflow near different types of screens in a greenhouse. Many Dutch growers are increasingly using various types of fans with different positions in the greenhouse for dehumidification and improved climate uniformity purposes. The effect of such fans on the air velocity near screens, and therefore the effect on energy and mass transfer, is unknown. For this purpose, air velocities near different types of screens in commercial greenhouses were measured using ultrasonic 3D anemometers. The results show that, in the absence of fans, air velocity near the screens is affected by vent opening. With vents closed, air velocities are hardly ever above 0.2 m s-1. Therefore, a simple air-suction device can be used to characterize permeability of screens at a very low Reynolds range.

Improving bending and dynamic mechanics performance of 3D printing through ultrasonic strengthening

Three-dimensional (3D) printed samples produced by fused deposition modeling (FDM) have low interlayer shear strength and poor bending mechanical properties owing to the technological characteristics of the accumulation of raster pattern and layers. The present study input ultrasonic vibration energy to 3D printed samples under pressure, and investigated the effects of ultrasonic vibration on the bending and dynamic mechanical properties of FDM 3D printed ABS samples. It was found that ultrasonic strengthening increased the bending strength of ABS samples by 10.8%, increased the bending modulus by 12.5%, and improved the dynamic mechanical properties. The combination of ultrasonic strengthening technology and FDM 3D printing technology can improve the flexural and dynamic mechanical properties of existing FDM 3D printed samples, and is important in broadening the application of 3D printed parts.