Article
Acoustics
Shuai Wang, Fengming Li
Summary: The study presents a novel hybrid-arranged perforated panel structure by integrating parts of panels with different perforated characteristics and cavity depths, which greatly enhances the sound absorption performance by adjusting parameters. The effectiveness of the analytical model is verified through the application of the equivalent circuit method and finite element numerical simulation, showing wideband and high sound absorption level of the model in acoustic experiments.
Article
Engineering, Mechanical
Weiping Yang, Yatsze Choy, Ying Li
Summary: In this study, the sound absorption performance of a wavy micro-perforated panel absorber (WMPPA) is investigated. The WMPPA exhibits promising potential for the control of low-frequency and broadband noise, with improved sound absorption performance at lower frequencies and additional absorption peaks in the middle to high-frequency range. The study validates the proposed model and uncovers the acoustical properties and performance enhancements of the WMPPA.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Xiyue Ma, Daniil Yurchenko, Kean Chen, Lei Wang, Yang Liu, Kai Yang
Summary: This paper investigates the performance of a new type of sound-controlled micro-perforated panel absorber, which achieves wide-band perfect low-frequency sound absorption using a point force controlled backing panel. The theoretical model is established and the influence of structure size and point force position on sound absorption performance is explored. Experimental tests are conducted to validate the findings, and the physical mechanisms of active control are analyzed. A simplified error sensing strategy is also constructed. The results show that locating the point force at the center or using a relatively small sized absorber can achieve perfect sound absorption in a wide controllable bandwidth.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Construction & Building Technology
Gunawan, Iwan Prasetiyo, Brian Yuliarto, Azma Putra, Irianto
Summary: Woven fabric perforation is beneficial for meeting the microstructure requirement of a micro-perforated panel absorber. The use of minute holes created by woven fabrics allows for the fabrication of high perforation ratio MPP with a diameter of 0.1-0.3 mm. The study discusses the properties of these minute holes and their associated absorption characteristics. Theoretical results and experimental investigations validate the findings, showing that controlling weft yarn density can successfully fabricate minute holes. The woven fabrics can achieve a half-absorption bandwidth of up to 5000 Hz (>3 octaves) with a peak absorption coefficient of over 0.8, and changing hole diameter can affect absorption behavior. The study confirms the applicability of Maa's model for predicting absorption of MPP using woven fabric material.
Article
Acoustics
Shanlin Yan, Jinwu Wu, Jie Chen, Yin Xiong, Qibo Mao, Xiang Zhang
Summary: The study investigated the sound absorption performance of micro-perforated plate under different parameters and designed two single-layer honeycomb micro-perforated plate structures using optimization algorithm to achieve broadband sound absorption. Experimental results showed that the depth of the perforations had a significant impact on the sound absorption performance, and using particle swarm optimization algorithm can improve the performance.
Article
Engineering, Mechanical
Xiang Liu, Chunqi Wang, Yumin Zhang, Lixi Huang
Summary: An investigation into a smart micro-perforated panel aims to enhance the sound absorption performance of MPP absorbers at low frequencies, utilizing a combination of mechanical damping, electrical shunt damping, and Helmholtz resonance. Different multimode shunt design methods are explored to intensify panel vibration and improve sound absorption, with absorption peaks induced by electromechanical coupling found at frequencies lower than the MPP's Helmholtz resonance frequency.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Acoustics
Xiyue Ma, Kean Chen, Lei Wang, Yang Liu, Shaohu Ding
Summary: This paper presents a theoretical investigation on actively controlling the low frequency sound absorption of large-sized micro-perforated panel absorber (MPPA) by using point source placed in the cavity. Results show that the sound absorption performance can be significantly improved, with the optimal position of the point source at the central of the cavity section. The control mechanism is to enhance the Helmholtz type resonant absorption.
Article
Acoustics
He Xu, Deyi Kong
Summary: This paper describes the theoretical prediction, simulation research, and experimental verification of finite cylindrical micro-perforated panel absorbers (FC-MPPAs) in noise control. The results show that FC-MPPAs have unique acoustic characteristics and their structural parameters are closely related to acoustic energy dissipation efficiency. The studies provide helpful insights for the design and application of FC-MPPAs to achieve better noise reduction effects.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Acoustics
Jingfeng Ning, Qian Geng, M. P. Arunkumar, Yueming Li
Summary: A light composite absorber with a micro-perforated sandwich panel filled with thin porous materials is proposed in this study to achieve a wide absorption bandwidth. The theoretical model derived by the transfer matrix method is in good agreement with experimental results, showing better performance compared to other absorbers. The absorption mechanism and the effects of internal components on absorption performance are analyzed in detail.
Article
Acoustics
Xiyue Ma, Lei Wang, Kean Chen, Xuhua Tian
Summary: This paper presents a comprehensive investigation on the passive and active low frequency sound absorption performance of the finite and large sized micro-perforated panel absorber (FLS-MPPA) for oblique incidence excitation (OIE). The theoretical model of the FLS-MPPA is established and validated, and the passive sound absorption performance and physical mechanisms are explored. The active control performance and physical mechanism of sound absorption improvement are also analyzed.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Acoustics
Chenhao Dong, Zhao Liu, Robert Pierce, Xiaoling Liu, Xiaosu Yi
Summary: A new micro perforated sandwich panel with honeycomb-hierarchical pore structure core is developed in this study. By combining carbonized cotton with hierarchical pore structure and a micro perforated honeycomb core, the sound-absorbing performance of the structure is enhanced without significant weight increase. Experimental results show that the average sound absorption coefficient of the structure can be improved from 0.220 to 0.558 with pure carbonized cotton filling, and further increased to 0.626 with hierarchical pore structure. Additionally, theoretical and finite element models are established with prediction errors of 16.8% and 8.6% respectively.
Article
Acoustics
Jiayu Wang, Gareth J. Bennett
Summary: This paper presents an optimised, multi-chamber, micro-perforated panel absorber (MC-MPPA) with micro-perforated adjoining panels. By employing a graph-theory-based method, a model for multi-chamber MPPAs can be developed, allowing the optimisation of different geometric parameters to achieve a broadband frequency response with a shallow cavity. Experimental results show that the MC-MPPA achieves an overall absorption coefficient of 0.83 in the frequency range of 660 Hz to 2 kHz and a depth-to-wavelength ratio of 20, making it a deeply subwavelength absorber.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Engineering, Mechanical
Wei He, Xiangjun Peng, Fengxian Xin, Tian Jian Lu
Summary: This study investigates the superior sound absorption performance of ultralight micro-perforated sandwich panels with double-layer hierarchical honeycomb core. Theoretical model predictions and numerical simulations validate the physical mechanisms underlying sound absorption, with systematic parametric study revealing optimal structural parameters for maximizing sound absorption. Viscous dissipation of air inside micro-perforations and around inlet/outlet regions is shown to dominate sound absorption, while the proposed hierarchical construction offers improved load-bearing capacity and significantly enhanced sound absorption across a wide frequency range compared to panels with regular honeycomb core.
JOURNAL OF SANDWICH STRUCTURES & MATERIALS
(2022)
Article
Acoustics
Teresa Bravo, Cedric Maury
Summary: This theoretical study applies the findings from electromagnetic research on radar slab absorbers to enhance the broadband dissipation of micro-perforated absorbers in the field of acoustics. A causal-based optimization criterion is proposed to find optimal absorbers that achieve maximum wideband performance and perfect absorption at their Helmholtz resonance frequency. The criterion maximizes the sensitivity of the total reflected intensity with respect to the absorber's constitutive parameters and can be easily implemented using numerical methods. It is shown to be a suitable alternative for single-layer absorber broadband optimization.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Acoustics
Heming Li, Jinwu Wu, Shanlin Yan, Qibo Mao
Summary: This paper presents the design and development of micro-perforated panel (MPP) absorbers with a variable section partition to solve the broadband sound absorption problem. Three types of MPP absorbers were developed based on the cavity, and their absorption characteristics were investigated and optimized. Experimental results show that the optimized absorbers have superior broadband sound absorption performance compared to conventional MPP absorbers.
Article
Engineering, Geological
Delfim Soares, Luis Godinho
Summary: This paper proposes two adaptive numerical approaches to analyze nonlinear porodynamic models, simplifying and decoupling each phase to obtain simpler, smaller, and better-conditioned systems of equations, which can be handled without iterative computation when considering nonlinear models. Additionally, incompressible and impermeable media can be directly analyzed without special discretization procedures.
Article
Engineering, Civil
Pedro Santos, Joao R. Correia, Luis Godinho, A. M. P. G. Dias, Andre Dias
Summary: A sandwich wall-panel solution based on Cross-Laminated Timber (CLT) called Cross-Insulated Timber (CIT) has been developed to improve thermal insulation and reduce weight. An environmental impact assessment using Life-Cycle Analysis (LCA) was conducted, showing that the manufacturing process of the CIT panel, specifically the production of polyurethane foam and the assembly processes, has the highest impacts. Varying the thickness of the wood layers compared to the optimized solution leads to increased environmental impacts, highlighting the importance of economic optimization in reducing environmental impact.
Article
Construction & Building Technology
M. Pereira, J. Carbajo, L. Godinho, J. Ramis, P. Amado-Mendes
Summary: Metaporous concrete, a combination of porous concrete and acoustic resonators, was studied using fluid-equivalent theory and experimental techniques, showing efficient prediction of sound absorption behavior and increased absorption coefficient peaks. The configuration MPCd of Metaporous concrete displayed excellent sound absorption performance.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Geological
Alexandre Castanheira-Pinto, Aires Colaco, Jesus Fernandez Ruiz, Pedro Alves Costa, Luis Godinho
Summary: In recent years, the railway sector has made significant advancements in terms of train speed, leading to new challenges in infrastructure performance. The critical speed effect, which amplifies track response and poses safety and maintenance concerns, can be mitigated through soil reinforcement with jet grouting columns. The reinforcement of layered grounds has been proven to considerably improve the critical speed of the railway system, and a simplified methodology for accurately predicting critical speed has been proposed.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Joao Lazaro, Matheus Pereira, Pedro Alves Costa, Luis Godinho
Summary: Rail transport is the most sustainable mode of transportation, but railway noise is a significant issue in urban areas. Noise barriers are commonly used to mitigate railway noise, but their height can make people feel enclosed. Placing the barriers close to the track may provide a solution. This paper illustrates the development of a low-height barrier solution using numerical modeling with the Boundary Element Method (BEM), which directs the energy back to the track to utilize the acoustic properties of the ballast.
APPLIED SCIENCES-BASEL
(2022)
Article
Acoustics
Denilson Ramos, Luis Godinho, Paulo Amado-Mendes, Paulo Mareze
Summary: In this study, a thin low frequency acoustic metamaterial called Acoustic Honeycomb Metasurface (AHS) is developed for wideband perfect absorption and sound transmission. The results show high absorption efficiency and low-frequency broadband absorption.
Article
Chemistry, Multidisciplinary
Laura Sousa, Luis Pereira, David Montes-Gonzalez, Denilson Ramos, Paulo Amado-Mendes, Juan Miguel Barrigon-Morillas, Luis Godinho
Summary: This study presents the use of porous concrete material with expanded clay as aggregate for the sound-absorption layer of noise barriers. A theoretical material model is calibrated using experimental data and validated through reverberant room measurements. Numerical simulations using the boundary element method (BEM) and CNOSSOS-EU calculation method show the performance of different types of barriers incorporating this material. Good insertion loss values can be achieved by carefully choosing the location of the material within conventional or low-height noise barriers.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Multidisciplinary
Kleber de Almeida Goncalves, Daniela Silva Santurio, Delfim Soares, Pedro Alves Costa, Luis Godinho
Summary: The use of boundary elements in the analysis of exterior acoustic problems faces challenges due to the presence of fictitious eigenfrequencies at internal resonances of cavities, which can lead to inaccurate results or unstable behavior. To address this non-uniqueness problem, a scheme based on the combined Helmholtz integral equation formulation (CHIEF) is proposed, although it requires additional equations and points. This study proposes a strategy to determine good approximations for the position and number of these points, based on an optimization process that maximizes the system matrix's smallest singular value. The proposed algorithms automatically circumvent the non-uniqueness problem, with low computational cost and simple implementation, thus aiding the development of more stable BEM codes.
APPLIED SCIENCES-BASEL
(2023)
Article
Acoustics
M. Veloso, M. Pereira, L. Godinho, P. Amado-Mendes, J. Redondo
Summary: Noise attenuation by sonic crystal noise barriers occurs mainly in specific frequency bands (bandgaps), due to a mechanism called Bragg scattering, which is the result of destructive interference between multiple reflections. Sound-absorbing materials can be used to coat the rigid scatterers to increase attenuation in other frequency bands. This study used the Method of Fundamental Solutions (MFS) to evaluate the performance of sonic crystal noise barriers covered with porous and granular materials. Numerical models were validated by experimental tests and compared with results obtained using the Finite Element Method (FEM). Numerical tests were performed to predict the acoustic behavior of sonic crystal noise barriers covered with porous concrete.
Article
Acoustics
Javier Redondo, Luis Godinho, Kestutis Staliunas, Juan Vicente Sanchez-Perez
Summary: The design and development of advanced devices based on metamaterials to control the transmission of acoustic waves is a hot topic. An important class of these metamaterials is based on phononic crystals with Locally Resonant Structure, included in those commonly known as Locally Resonant Sonic Materials. The authors develop a comprehensive numerical model of periodic arrays of Hemholtz resonators, which explains in detail the physical mechanisms of destructive interference and allows the reproduction of the consequences of the interference. The numerical results are supported by experimental tests.
Article
Environmental Sciences
Tommaso D'Orazio, Francesco Asdrubali, Luis Godinho, Matheus Veloso, Paulo Amado-Mendes
Summary: Recent research has focused on the application of sonic crystals as noise barriers and exploring aspects for their further development. The study validates numerical models using laboratory experimentation and finite element method (FEM) computation, providing confidence for analyzing practical sonic crystal configurations. The research also examines various geometric arrangements of the scatterers and introduces randomness to analyze their effect on the sonic crystal's insertion loss.
Article
Chemistry, Multidisciplinary
Javier Redondo, Pau Gaja-Silvestre, Luis Godinho, Paulo Amado-Mendes
Summary: This study explores the relationship between insertion loss and acoustic insulation and proposes a method to predict insertion loss through acoustic numerical simulation.
APPLIED SCIENCES-BASEL
(2022)
Article
Acoustics
Cailiang Zhang, Zhihui Lai, Zhisheng Tu, Hanqiu Liu, Yong Chen, Ronghua Zhu
Summary: This paper proposes two single-parameter-adjusting SR models to optimize the output performance of SR systems. The effects of the proposed models on SR output under different parameters and signals are investigated through numerical simulations, and their feasibility is verified through experimental results. The research results are of great significance for guiding the design of tri-stable SR models and the application of SR-based signal processing in the context of big data.
Article
Acoustics
Shaoqiong Yang, Hao Chang, Yanhui Wang, Ming Yang, Tongshuai Sun
Summary: In this study, a suspension system based on phononic crystals is designed for vibration isolation of acoustic loads in underwater gliders. The vibration properties of the phononic crystals and the effects of physical parameters on the underwater attenuation zones are investigated. Vibration tests show that the phononic crystal suspension system has a stable vibration isolation effect in the frequency range of 120-5000 Hz.
Article
Acoustics
Xuebin Zhang, Jun Zhang, Tao Liu, Ning Hu
Summary: This study proposes a tunable metamaterial beam to isolate flexural waves. A genetic algorithm-based size optimization is used to obtain a broad low-frequency bandgap. The tunability of the beam is achieved by attaching different numbers of permanent magnets to change the mass of the resonators. Additionally, ultra-broadband flexural wave attenuation is achieved by forming a gradient metamaterial beam based on the rainbow effect. Numerical and experimental results confirm the good flexural wave attenuation ability of the proposed beam.
Article
Acoustics
Luca Rapino, Francesco Ripamonti, Samanta Dallasta, Simone Baro, Roberto Corradi
Summary: This paper presents a method for simulating tyre/road noise using equivalent monopoles, including the synthesis of monopoles through an inverse problem approach and the use of an ISO 10844 road replica for laboratory testing. The method combines acoustic finite element models and numerical simulations of vehicles, and the results are validated by comparing them with measured data.
Article
Acoustics
Xiaoyan Zhu, Tin Oberman, Francesco Aletta
Summary: This paper explores the definition of acoustical heritage and proposes a multidimensional definition based on interviews with experts and detailed analysis of the data.
Article
Acoustics
Faeez Masurkar, Saurabh Aggarwal, Zi Wen Tham, Lei Zhang, Feng Yang, Fangsen Cui
Summary: This research focuses on estimating the elastic constants of orthotropic laminates using ultrasonic guided waves and inverse machine learning models. The results show that this approach has the potential to accurately predict the elastic constants of a material and reduce computational time.
Article
Acoustics
Feng Xiao, Haiquan Liu, Jia Lu
Summary: Diagnostic methods for cardiovascular disease based on heart sound classification have been widely studied due to their noninvasiveness, low-cost, and high efficiency. However, existing research often faces challenges such as the nonstationarity and complexity of heart sound signals, leading to limited capability of neural networks to extract discriminative features. To address these issues, this study proposes a novel convolutional neural network that combines 1D convolution and 2D convolution, and introduces an attention mechanism to enhance feature extraction capability. The study also explores the advantages and disadvantages of combining deep learning features with manual features, and adopts an evolving fuzzy system for decision-making interpretability.
Article
Acoustics
Hong Xu, Zhengyao He, Qiang Shi, Yushi Wang, Bo Zhang
Summary: This paper presents the development of a directional segmented ring transmitting transducer that can radiate sound waves in any horizontal region. The study focuses on the structure of the segmented ring transducer, its radiation sound field characteristics, and the beam pattern control method based on modal synthesis. The authors propose orthogonal beam pattern functions for adjusting steering angles and establish a three-dimensional finite element model to simulate the transmitting beam patterns. Experimental measurements and tests validate the effectiveness of the proposed transducer, showcasing its ability to steer the beam patterns to different directions.
Article
Acoustics
Jirui Yang, Shefeng Yan, Di Zeng, Gang Tan
Summary: This paper proposes an improved domain adaptation framework, self-supervised learning minimax entropy, to enhance the recognition performance of underwater target recognition models. The experimental results demonstrate that applying domain adaptation methods can effectively improve the recognition accuracy of the models under various marine conditions.
Article
Acoustics
Zonghan Sun, Jie Tian, Yuhang Zheng, Xiaocheng Zhu, Zhaohui Du, Hua Ouyang
Summary: This paper analyzes the noise reduction method of installing a sinusoidal-shaped inlet duct on a cooling fan through theoretical and experimental analysis of the acoustic mode modulation. The study establishes the correlation between the free field noise and acoustic mode of the fan rotor and the unsteady forces on the rotor blade surface. The results show that the sinusoidal-shaped inlet duct achieves greater noise reduction compared to a straight duct, especially at the blade passing frequency and its first harmonic.
Article
Acoustics
Min Li, Rumei Han, Hui Xie, Ruining Zhang, Haochen Guo, Yuan Zhang, Jian Kang
Summary: This study is part of a global collaboration to translate and standardise soundscape research. A reliable questionnaire for soundscape characterisation in Mandarin Chinese was developed and validated. The study found that salient sound sources become the focus of attention for individuals in urban open spaces, and the perception is also influenced by the acoustic characteristics of the soundscape. Certain types of sound sources play a more important role in soundscape perception.
Article
Acoustics
Arezoo Talebzadeh, Dick Botteldooren, Timothy Van Renterghem, Pieter Thomas, Dominique Van de Velde, Patricia De Vriendt, Tara Vander Mynsbrugge, Yuanbo Hou, Paul Devos
Summary: This study proposes a sound selection methodology to enhance the soundscape in nursing homes and reduce BPSD by analyzing sound characteristics and recognition methods. The results highlight the sound characteristics that lead to positive responses, while also pointing out the need for further studies to understand which sounds are most suitable for people with dementia.
Article
Acoustics
Yang Yang, Yongxin Yang, Zhigang Chu
Summary: This paper introduces a grid-free compressive beamforming method compatible with arbitrary linear microphone arrays, and demonstrates the correctness and superiority of the proposed method through examples. Monte Carlo simulations are performed to reveal the effects of source coherence, source separation, noise, and number of snapshots.
Article
Acoustics
Sukru Selim Calik, Ayhan Kucukmanisa, Zeynep Hilal Kilimci
Summary: Computer-Aided Language Learning (CALL) is growing rapidly due to the importance of acquiring proficiency in multiple languages for effective communication. In the field of CALL, the detection of mispronunciations is vital for non-native speakers. This research introduces a novel framework using audio-centric transformer models to detect mispronunciations in Arabic phonemes. The results demonstrate that the UNI-SPEECH transformer model yields notable classification outcomes in Arabic phoneme mispronunciation detection. The comprehensive comparison of these transformer models provides valuable insights and guidance for future investigations in this domain.
Article
Acoustics
Yi-Yang Ni, Fei-Yun Wu, Hui-Zhong Yang, Kunde Yang
Summary: This paper proposes an improved method for compressive sensing by introducing a self training dictionary scheme and a CS reconstruction method based on A*OLS, which enhances the sparse representation performance of propeller signals.
