bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupled vibration characteristics and optimization design of the cylindrical-exponential ultrasonic concentrator
Authors: Xu Jie , Wang Guozhang , Lin Jiyan 
Published: October 2024

Abstract
In this study, the vibrations of cylindrical-exponential ultrasonic concentrators are investigated, with the objective of improving energy transfer efficiency. Traditional analyses, often one-dimensional, have been found to inadequately consider the effects of height on vibration behaviour. To address this gap, the equivalent elasticity method is employed to provide a more comprehensive understanding of vibrational phenomena. The coupled vibration of the concentrator is regarded as an interaction between a longitudinal vibration and a plane radial vibration. A mechanical coupling coefficient is introduced, establishing a link between these vibrational modes. Equivalent circuits for radial and longitudinal vibrations are derived, and input impedances are presented as functions of resonance frequency and mechanical coupling coefficient. These analyses enable an exploration of the impact of geometric dimensions on the vibrational characteristics. To validate our theoretical model, the finite element method is used to simulate the coupled vibration and the results confirm the efficacy of the approach.
Research on Frequency of Radial Vibration of Elastic Thin Spherical Shell
Authors: Haidao Zhang , Long Xu , Fengming Li 
Published: October 2024

Abstract
The ultrasonic frequency radial vibration of an elastic thin spherical shell composed of isotropic materials is studied, the frequency equation of its vibration is deduced, and the equivalent circuit is obtained. The finite element software COMSOL is used to verify the obtained analytical theory, and the calculated results are basically consistent with the theoretical calculated values. The relevant conclusions provide references for the application of spherical shell structure in related fields.
Open-slit circular tube piezoelectric ultrasonic transducer with longitudinal bending mode conversion
Authors: Li Fengming , Liu Shiqing , Xu Long , Zhang Haidao , Zeng Xiaomei , Chen Zhaojiang 
Published: October 2024

Abstract
A new type of longitudinal bending mode conversion ultrasonic transducer is designed by compounding a sandwich type piezoelectric ultrasonic transducer, amplitude transformer and Open-slit circular tube radiator. The radiator is made of a circular tube cut into a number of curved plates along the axis, and the two ends are thin disc end caps. The electromechanical equivalent circuit model of the transducer is established and its frequency equation is derived. The vibration performance of the transducer is studied by using the equivalent circuit method and the finite element method. The results show that: the new structure design and the longitudinal vibration sandwich piezoelectric ultrasonic transducer can effectively stimulate the two ends of the slit circular tube radiator to produce first-order bending vibration, and the curved plate to produce high-order bending vibration, so as to achieve high efficiency, uniform and all-round ultrasonic radiation. The research results are expected to be applied in ultrasonic treatment of large volume liquid such as ultrasonic wastewater treatment, ultrasonic algae removal and ultrasonic chemical reaction.
Application of optical fiber distributed acoustic sensing system in ultrasonic detection
Authors: Xiao Yanbo , Ran Zengling , Yi Jicai , Chen Qiaoling , Chen Ziqiang , Zhu Qingqiang , Cui Jianxin , Rao Yunjiang , Wang Ximing , An Shujie , Chen Yuanzhong , Wu Junjun 
Published: October 2024

Abstract
The optical fiber distributed acoustic sensing system can continuously detect acoustic signals along the optical fiber, with the characteristics of wide response frequency band, large capacity, anti-electromagnetic interference and so on. An ultra-sensitive distributed optical fiber acoustic sensing system (uDAS) was produced with a high response frequency up to 100 kHz and thousands of sensing points. The arrayed ultrasonic detection can be realized by the distributed characteristics of the system. For verifying its ultrasonic detection ability, it is applied to ultrasonic nondestructive testing of structural defects. 20 optical fiber ultrasonic detection units were constructed. Each one is a fiber ring with a diameter of about 1.5 cm and a length of 2 meters. Two cubic cement structures with a side length of 30 cm were manufactured for experiment, one of which had an artificial internal defect. The optical fiber array was attached to the surface of the cement structure, and the ultrasonic signal with a frequency of 40 kHz was excited at a single point on the opposite side. The ultrasonic propagation speed changes on account of the defects such as holes and loose texture in the propagation path. The defects in the structure are identified and located by analyzing the difference of arrival time of waves. It is expected that such sensing system could found important applications in structure defect detection.
A novel theoretical analysis method for the longitudinal cascaded piezoelectric transducer based on equivalent circuit
Authors: Li Guo , Lei Ming , Xu Huan , Han Shuyang , Zeng Yan , Li Yujiao 
Published: October 2024

Abstract
High power ultrasonic transducers are widely used in the fields of ultrasonic cleaning, ultrasonic welding and therapeutic ultrasound. To further improve the ultrasonic intensity and power of piezoelectric transducers for power ultrasound applications, the cascaded piezoelectric transducer have received tons of attention. The electromechanical equivalent circuit, as a classical transducer analysis method, translates the structural and mechanical parameters into the corresponding circuit parameters and helps us to better understand and analyze the performance characteristics of the transducer, which is of great significance for the design and optimization of the transducer. In this paper, a new theoretical analysis method based on the equivalent circuit is proposed for cascaded piezoelectric transducer. In this method, the equivalent circuit of each component of the longitudinal piezoelectric transducer is cascaded, and equivalent circuit is analyzed using the Kirchhoff’s law to obtain the frequency resonance equation of the piezoelectric transducer. This analysis method avoids the complex equivalent transformation of the equivalent circuit including multiple excitation sources and also obtains the vibration velocity of the piezoelectric transducer radiation surfaces, more information on the vibration characteristics of the transducer was gained from the theoretical aspect. Finally, the theoretical analysis results are compared with the finite element simulation analysis and the traditional analysis results for verification.
The Effect of the Movement of a Passive Reflector on the Atomization of a Levitating Drop
Authors: Meneses-Díaz J. , Cancino-Jaque E. , Carrión-Acuña M. , Vargas-Hernández Y. , Gaete-Garretón L. 
Published: October 2024

Abstract
This study investigates the instability of distilled water drops under acoustic levitation induced by the movement of a reflector toward the transducer. The experimental setup consisted of a passive concave reflector and a Langevin transducer in a uniaxial-resonance configuration. The experiment consists of achieving a stable levitation of the droplet and then moving the reflector constantly toward the transducer, shortening the distance h between them (reflector-transducer). All experiments were recorded using a high-speed camera to analyze the drop’s behavior. The results revealed three distinct instabilities: radial atomization occurred when the drop volume (VD
) was ≤ 3.74 μl, beyond which central atomization was observed. A third instability is observed when a low reflector velocity (Vr
< 0.67 mm/s) is used, where the droplet exhibited modes of oscillation with pulsed central atomization.
A 2D Ultrasonic Phased Array Optimization Framework Enabled by Reconfigurable Laser Induced Phased Arrays
Authors: Lukacs Peter , Davis Geo , Pieris Don , Stratoudaki Theodosia 
Published: October 2024

Abstract
Three-dimensional (3D) ultrasonic imaging enables the viewing of internal features in a more accurate way than cross-sectional imaging. 3D imaging requires two-dimensional (2D) ultrasonic phased arrays to resolve all three spatial dimensions through beamforming along azimuthal and elevation angles. 2D phased arrays pose a manufacturing and control challenge due to the requirement of large number of elements to satisfy the Nyquist sampling limit. This problem can be alleviated through the use of sparse ultrasonic array designs. The optimization process is critical, as this dictates the efficiency of suppression of grating lobes. The aim of this work is to establish a framework for design of optimized sparse 2D phased arrays. This is enabled by exploiting the reconfigurability of Laser Induced Phased Arrays (LIPAs). LIPAs are synthetic arrays produced by scanning one laser for ultrasound generation and another for ultrasound detection, independently of each other. The reconfigurability and decoupled ultrasonic generation and detection of this systems enables easy and fast implementation of any arbitrary array layout. The framework consists of an analytical model for parametric evaluation of designs. The model performs a parametric sweep on the generation and detection element positions for each array design in order to identify the optimal parameters, based on mean and maximum side-lobe level. In the presented framework, four array designs are utilized for the optimization process: matrix, random, Vernier and a novel array design the Rotated Array (RA).
Quartz enhanced low sampling trace gas detection
Authors: Yang Shangjie , Zhong Yuanxin , Liu Zheng , Dong Huikun , Gao Chunming , Gong Yanli 
Published: October 2024

Abstract
Dectection of the exhaled gas, which can effectively reflect human health status, analyze and predict diseases has become a research focus. Quartz enhanced photoacoustic spectroscopy (QEPAS) technology has the advantages of small volume, low cost, and high sensitivity, exhibiting great potential in exhaled gas detection. In this work, small volume fractions of CO were detected by QEPAS technology. Optimizing the structure based on finite element method and designing circuit, a detection system with adjustable photoacoustic cell pressure was established. Then, the corresponding relationship between gas volume fraction and response signal was calibrated by the detection of multiple volume fractions of CO. The system has shown a volume fraction detection limit of 531.2×10−9, with a normalized noise equivalent absorption coefficient of 2.86×10−8 cm−1/Hz1/2 and an average detection error of less than 0.8%. The results indicate that our QEPAS system could monitor the exhaled CO trace gas, showing broad application prospects.
Design and Characterization of SAW-Based Wireless and Passive Temperature Sensing System
Authors: Zhou Zhixin , Wang Hui , Chen Minkan , Zhang Linwei , Lou Liang 
Published: October 2024

Abstract
The Surface Acoustic Wave (SAW) temperature sensor has received significant attention due to its wirelessly-powered, battery-free, and chipless capabilities. This paper proposes a wireless sensing system comprising a one-port SAW resonator, antennas, and transceiver circuit. The SAW resonator utilized in this system was based on Aluminum Nitride (AlN) thin film, which exhibits high SAW velocity and excellent piezoelectric properties. To completely investigate the performance of the SAW resonator, simulation and experiments were conducted. Upon connecting the SAW sensor to the temperature sensing system via the antenna, the reflection peak of the SAW resonator was clearly observed in the spectrum of the return signal. Additionally, during the temperature tests, the response frequency displayed almost linear behavior as the temperature increased from 30°C to 150°C. The fitted temperature coefficient of frequency (TCF) was 30.68ppm/°C, indicating that the wireless temperature sensing system has high temperature sensitivity.
Numerical studies of one-way Lamb and SH mixing method in composite laminates with transverse-isotropic quadratic nonlinearity
Authors: Liu Xiang , Zhao Youxuan , Deng Mingxi , Hu Ning 
Published: October 2024

Abstract
The resonant behavior of one-way Lamb and SH (shear horizontal) mixing method in composite laminates with transverse-isotropic quadratic nonlinearity is investigated through numerical simulations in this paper. Different from previous studies, the composite constitutive model is combined from orthotropic elasticity and transverse-isotropic quadratic nonlinearity, which is implemented by ABAQUS/VUMAT subroutine. When two fundamental waves (S
0-mode Lamb waves and SH
0 waves) mix in composite laminates with quadratic nonlinearity, the resonant SH
0 waves can be generated with the resonance condition ω

S
0
/ω

SH
0
= 2 κ/(κ + 1). Meanwhile, the relationships between the acoustic nonlinear parameter (ANP) and damage degree, fundamental frequency, frequency deviation, propagation distance are also investigated. Moreover, the method of locating the damage region in composite laminates is proposed and verified by using the resonant wave time-domain signal.
Nonlinear interaction of Lamb waves with fatigue cracks in metal plates under the condition of phase-velocity mismatching
Authors: Sun Di , Zhu Wujun , Xiang Yanxun 
Published: October 2024

Abstract
Nonlinear Lamb waves have been widely acknowledged as an efficient method for evaluating material damage at an early stage. However, due to the dispersive and multimode natures of Lamb waves, nonlinear Lamb waves with exact/approximate phase-velocity matching have been employed in previous research solely for the evaluation of fatigue cracks. Second harmonic Lamb waves can be generated from the contact acoustic nonlinearity (CAN) induced by the “breathing” effect of fatigue cracks. This paper presents a verification of the second harmonic S0 mode Lamb waves due to fatigue crack CAN, despite the mismatch in phase velocity between this mode and the primary S0 mode Lamb waves. This verification is achieved through both simulation and experiment. Consequently, the generation of double-frequency Lamb waves by fatigue cracks under conditions of phase velocity mismatching is validated. Furthermore, the phase-velocity mismatching method is anticipated to exclude material nonlinearity in the detection of fatigue cracks. This method offers a potential for accurate detection and evaluation of fatigue cracks.
Non-contact Non-linear Impact Resonance Acoustic Spectroscopy for thermal damage characterization on mortar samples
Authors: Gosálbez J. , Carrión A. , Gallardo C. , Madrigal J. 
Published: October 2024

Abstract
The high sensitivity of the nonlinear terms of the elastic response of materials to the incipient appearance of damage has led to the appearance of the Non-linear Elastic Wave Spectroscopy methods (NEWS). Particularly, the Non-linear Impact Resonance Acoustic Spectroscopy (NIRAS) technique detects changes in the resonance of a material (frequency, damping factor, etc.) as a function of the intensity of the impact. Traditionally, mechanical waves have been monitored using an external sensor in contact with the material. Currently, alternative technologies are capable of capturing mechanical waves without direct contact or with embedded sensors in the material itself from its manufacture. This helps the automation process or the continuous monitoring of the material. Mortar is the most used composite material in construction. In this work, thermal damage on mortar samples is characterized by NIRAS tests using different sensing techniques. Accelerometers have been used as the reference technique, while laser interferometer and Fiber Bragg Grating (FBG) have been used as non-contact and embedded sensor techniques respectively. Two levels of damage are presented: sound samples and 400ºC damage. The different techniques offer similar results, showing the capability of the proposed techniques (FBG and laser interferometry) to be an accurate alternative to traditional contact techniques for NIRAS testing.
An approximation method to determine the travel time in total focusing imaging of carbon fiber-reinforced laminates
Authors: Cao Ziyi , Shi Fangfang 
Published: October 2024

Abstract
It is critical to accurately determine the propagation time in testing objects for ultrasonic array imaging using the Total Focusing Method (TFM). However, it poses challenges for the calculation of wave propagation time in carbon fiber reinforced polymer (CFRP) laminates because of the material anisotropy and inhomogeneity. This paper introduces a novel approach for computing ultrasonic wave travel time to enhance the TFM image of CFRP laminates. This method, termed the layer-by-layer acoustic travel time approximation (L-L TravelTimeAppro), considers the anisotropy within each monolayer and the heterogeneity of CFRP. It approximates the propagation path as straight throughout the material and computes the wave propagation duration utilizing the group velocity in each ply. The application of this method to TFM imaging is referred to as TravelTimeAppro-TFM. Experiments were conducted in a specially designed CFRP laminate. Subsequently, TFM imaging was processed by using propagation time calculated by isotropic, Dijkstra, and L-L TravelTimeAppro methods, respectively. The results indicate that TravelTimeAppro-TFM outperforms isotropic-TFM in terms of imaging amplitude gain with a maximum gain of 4.67 dB. Furthermore, it offers superior computational efficiency compared to Dijkstra-TFM.
Solving the Scattering and Reflecting Properties of Guided Waves in CFRP under Arbitrary Oblique Incidence Based on Spectral Method
Authors: Gao Lei , Feng FeiLong 
Published: October 2024

Abstract
In this paper, the Chebyshev allocation point was used to sample the plate thickness and the spectral method was used to solve the differential characteristic equation of obliquely incident-guided waves in CFRP plates, which was transformed into a matrix equation. After obtaining the mode solutions of obliquely incident guided waves, the spectral method was also used to solve the integral equations required for mode matching of guided waves at the end and step-change positions of the CFRP plate. Numerical results show that the spectral method can accurately calculate the dispersion curve of complex wave number guided waves, and compared with commonly used finite element simulation schemes, this method can quickly and accurately calculate the scattering solutions of plane-guided waves at these transverse defect positions.
Dispersion and Attenuation Estimation of Ultrasonic Guided Waves using Multi-Subarrays Matrix Pencil Method
Authors: Zheng Shuhang , Xu Kailiang , Tran Tho N.H.T. , Minonzio Jean-Gabriel 
Published: October 2024

Abstract
Dispersion and attenuation estimation of ultrasonic guided waves is important for waveguide characterization. Matrix pencil (MP) method has been proposed for multimode complex wavenumber estimation, but its performance highly depends on the signal to noise ratio (SNR), which still brings challenges for high attenuation waveguide evaluation. In addition, the model order, i.e., matrix size in MP method, significantly impacts the dispersion curve extraction. In this study, to avoid the model order interference and compensate the SNR sensitivity of the classical MP algorithm, a multi-subarrays MP method is proposed for accurate dispersion and attenuation estimation. Considering with different Hankel matrix sizes, the multi-subarrays MP method estimates the complex wavenumbers from each pair of submatrices to filter uncertain results. A soft threshold strategy is applied to compensate the noise sensitivity of the estimation. Simulated results prove the proposed method can improve the dispersion and attenuation curve estimation.
Estimation of temperature-dependent piezoelectric material parameters using ring-shaped specimens
Authors: Friesen O , Claes L , Scheidemann C , Feldmann N , Hemsel T , Henning B 
Published: October 2024

Abstract
Simulation-driven design processes of piezoelectric actuators and sensors necessitate precise material parameter knowledge. Historically, the IEEE standard on piezoelectricity is used for this purpose, which proposes an analytical method for material parameter identification based on resonance frequency evaluations. This method requires different impedance measurements on differently shaped and processed samples, which yields inconsistent material parameter sets due to processing effects on material properties. Previous studies show that an inverse procedure using a single disc-shaped specimen with some adaptations can be used to identify a full set of parameters. As high-power actuators often use ring-shaped components, this method needs adaptation for this kind of specimen. Furthermore, the dependence of the material parameters on temperature needs to be considered to characterise the temperature effects and the associated non-linear effects of the specimens. For this purpose, samples with different geometrical dimensions at a range of different temperatures are examined in this study. Material parameters are then estimated using an inverse approach utilising the measurement data in conjunction with a numerical FEM simulation model. The observed temperature dependence of the estimated material parameters is examined and presented in this contribution.
A Method of Ship Target Modulation Feature Enhancement Based on Phase Information
Authors: Zhang Xin , Shang Jintao , Ye Simao , Yang Liu 
Published: October 2024

Abstract
Ship modulation features are commonly used in underwater acoustic target recognition, which contains propeller parameter information of the target. The basis processing of modulation spectrum is demodulation. Traditional envelope demodulation methods only consider amplitude information and make little use of phase information, which can fully characterize the dynamic characteristics of radiated noise. In this paper, a modulation feature enhancement method based on phase information is proposed, which takes full account of the phase information of the target signal. It uses the modified group delay function to demodulate the target signal, and utilizes the phase stability characteristics of the modulated line spectrum to enhance the modulation features of the ship target by weighted phase features. Simulation and sea trial data verification show that the proposed method can effectively enhance the energy of the line spectrum, suppress the background noise, and improve the signal-to-noise ratio of the modulation line spectrum, which lays a good foundation for further using the modulation line spectrum to carry out the estimation of modulation parameters, and has a good application prospect in the field of underwater acoustic target recognition.