International Journal of Acoustics and Vibration最新文献_第7页

Design of Ultrasonic Transducer for Secondary Wave Generations with High Directivity 高指向性二次波发生器超声换能器的设计

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41460

Chol-Hak Kim, Myong-jin Kim, Chol-Su Ri

引用次数: 0

Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient 非对称旋转锥形夹层梁在热梯度脉动轴向载荷作用下的静动力稳定性分析

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41363

M. Pradhan, P. Dash

引用次数: 0

Fluid Acoustic Properties of Improved Hydraulic Mufflers with Extended Necks 改进型长颈液压消声器的流体声学特性

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41327

Fan Yang, B. Deng

引用次数: 0

Fault Feature Extraction and Degradation State Identification for Piezoelectric Ceramics Cracking in Ultrasonic Motor Based on Multi-Scale Morphological Gradient 基于多尺度形态梯度的超声电机压电陶瓷裂纹故障特征提取与退化状态识别

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41464

Guoqing An, Hong-ru Li, Baiyan Chen

{"title":"Fault Feature Extraction and Degradation State Identification for Piezoelectric Ceramics Cracking in Ultrasonic Motor Based on Multi-Scale Morphological Gradient","authors":"Guoqing An, Hong-ru Li, Baiyan Chen","doi":"10.20855/ijav.2019.24.41464","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.41464","url":null,"abstract":"Piezoelectric ceramics cracking is one of the main faults of the ultrasonic motor. According to the morphological mathematics and information entropy, a method based on multi-scale morphological gradient was proposed for ceramics fault feature extraction and degradation state identification. To solve the problem that traditional multi-scale morphology spectral (MMS) entropy cannot exactly describe the performance degradation of the piezoelectric ceramics, multi-scale morphology gradient difference (MMGD) entropy was proposed to improve the sensitivity to the fault. Furthermore, multi-scale morphology gradient singular (MMGS) entropy was presented to reduce the system noise interference to the useful fault information. The disturbance analysis of temperature, load, and noise for MMGD entropy and MMGS entropy was also given in this paper. Combining the advantages of the above two entropies, a standard degradation mode matrix was built to distinguish the degradation state via the grey correlation analysis. The analysis of actual test samples demonstrated that this method is feasible and effective to extract the fault feature and indicate the degradation of piezoelectric cracking in ultrasonic motor.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48697773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Field Test Research and Numerical Simulation on Aerodynamic Deloading Characteristics of V-Shaped Noise Barrier V型声屏障气动减载特性的现场试验研究与数值模拟

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41468

J. Zhao, Ning Zhi, Lü Ming

{"title":"Field Test Research and Numerical Simulation on Aerodynamic Deloading Characteristics of V-Shaped Noise Barrier","authors":"J. Zhao, Ning Zhi, Lü Ming","doi":"10.20855/ijav.2019.24.41468","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.41468","url":null,"abstract":"With the rapid development of the high-speed railway in China, the problems of the noise pollution induced by passing trains emerge. Theoretically, the V-shaped noise barrier is of pretty good performance of noise-reduction and load-shedding. To assess the practical aerodynamic deloading characteristics of the V-shaped noise barrier, a full-scale field test was carried out at three measuring-sections equipped with noise barriers of different heights. In order to quantify the research work, the impact strength and deloading rate were selected as indicators. The effects of train speeds, train types and barrier heights are studied. This study includes the variations of impact strength and deloading rate in vertical directions. Meanwhile, 2D numerical simulation research is conducted to analyze the experimental results from the angle of mechanism. It is observed that the aerodynamic load acting on the surface of the V-shaped noise barrier was weaker and more uniform compared with conventional barrier. The flow field distribution influenced the deloading characteristics of the V-shaped noise barrier significantly. Moreover, the load-shedding effect of V-shaped noise barrier, when CRH380AM passed by, was slightly better than CRH380A. The deloading rate improved with the increasing of the noise barrier height in general.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46595045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Maritime Airborne Noise: Ships and Harbours 海上空气噪音:船舶和港口

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.4e94

D. Borelli

引用次数: 8

Numerical Investigation of Surface Acoustic Wave (SAW) Interacting with a Droplet for Point-of-Care Devices 表面声波（SAW）与护理点设备液滴相互作用的数值研究

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41312

Imran Shah, E. Uddin, A. Mubashar, M. Younis, Hudair Samad, K. Choi

{"title":"Numerical Investigation of Surface Acoustic Wave (SAW) Interacting with a Droplet for Point-of-Care Devices","authors":"Imran Shah, E. Uddin, A. Mubashar, M. Younis, Hudair Samad, K. Choi","doi":"10.20855/ijav.2019.24.41312","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.41312","url":null,"abstract":"A three-dimensional numerical simulation of the interaction of a surface acoustic wave (SAW) with a droplet of water is carried out. The mixing produced inside the droplet due to the incident with the SAW and the droplet is investigated by undertaking a parametric study, with parameters such as frequency, drop size, and the lateral position of the droplet on the surface of the substrate. The linear relationship between the input voltage and the mixing velocity inside the droplet is obtained with variation of the input voltage of the inter-digital transducer (IDT) of the SAW device within a 10–40 V range. With the variation in frequency, the maximum mixing velocity is observed at 20 MHz and it appears to be independent of the size of the droplet. Varying the substrate material with lead zirconate titanate and lithium niobate produces better mixing. Lithium niobate is preferred due to its availability and cost-effectiveness. A drop of 600 μm diameter produces better mixing. The different velocities inside the drop and the SAW device are obtained by changing the droplet position in the lateral direction (asymmetrical position) from the centre of the substrate. Cut planes parallel and perpendicular to the SAW at the core of a half-spherical droplet are observed to visualise the mixing effects inside the droplet during the interaction. To achieve the best mixing criteria, the droplet is moved in a lateral direction. An efficient parametric design for the mixing phenomena in micro-fluidic devices is presented for point-of-care devices.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46267136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Stochastic Minimax Vibration Control for Uncertain Nonlinear Quasi-Hamiltonian Systems with Noisy Observations 具有噪声观测的不确定非线性拟哈密顿系统的随机极大极小振动控制

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41446

Z. Ying, R. Hu, R. Huan

{"title":"Stochastic Minimax Vibration Control for Uncertain Nonlinear Quasi-Hamiltonian Systems with Noisy Observations","authors":"Z. Ying, R. Hu, R. Huan","doi":"10.20855/ijav.2019.24.41446","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.41446","url":null,"abstract":"A stochastic minimax control strategy for uncertain nonlinear quasi-Hamiltonian systems with noisy observations under random excitations is proposed based on the extended Kalman filter and minimax stochastic dynamical programming principle. A structure system with smart sensors and actuators is modeled as a controlled, excited and dissipative Hamiltonian system with noisy observations. The differential equations for the uncertain nonlinear quasi-Hamiltonian system with control and observation under random excitation are given first. The estimated nonlinear stochastic control system with uncertain parameters is obtained from the uncertain quasi-Hamiltonian system with noisy observation. In this case, the optimally estimated state is determined by the observation based on the extended Kalman filter. The dual dynamical programming equation for the estimated uncertain system is then obtained based on the minimax stochastic dynamical programming principle. The worst-case disturbances are determined for bounded uncertain parameters and the optimal control law is determined for the worst case by the programming equation. The proposed minimax control strategy is applied to two uncertain nonlinear stochastic systems with controls and noisy observations. The control effectiveness for the stochastic vibration response reductions of the systems is illustrated with numerical results. The proposed minimax control strategy is applicable to general uncertain nonlinear multi-degree-of-freedom structure systems with noisy observations under random excitations.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46712900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Why Balloons Make a Loud Noise When They Pop 为什么气球弹出时会发出巨大的噪音

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41433

E. Ross, J. Panda, J. Ross, L. K. Kushner

引用次数: 0

Oversampled Modal Approach of a Turbocharger Rotor from the Experimental Lateral Vibrations 涡轮增压器转子横向振动的过采样模态方法

IF 1 4区工程技术

International Journal of Acoustics and Vibration Pub Date : 2019-12-31 DOI: 10.20855/ijav.2019.24.41484

L. A. Montoya, E. E. Rodriguez, H. J. Zúñiga, I. Mejía

{"title":"Oversampled Modal Approach of a Turbocharger Rotor from the Experimental Lateral Vibrations","authors":"L. A. Montoya, E. E. Rodriguez, H. J. Zúñiga, I. Mejía","doi":"10.20855/ijav.2019.24.41484","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.41484","url":null,"abstract":"The elements of rotors have inherent characteristics as geometry and material composition, which causes natural vibrations at frequencies that, due to the rotor unbalance, may coincide with the harmonics of the shaft speed, increasing stress and the probability of fractures even in transient conditions. Therefore, in this work, a theoreticalexperimental hybrid method for calculating the natural frequencies and the mode shapes, at rest and non-supported conditions, of a turbocharger rotor is proposed. Firstly, a discrete model of low number of degrees of freedom is considered, and from an oversampled modal approach (OSMA) based on the axial oversampling, sectioning and coupling of the rotor, it is possible to use the oversampled mode shapes to increase the degrees of freedom of the system without major complications in the model. This spatial oversampling criterion is based on the NyquistShannon theorem, and it is used to reduce the error in the estimates of the natural frequencies and to get a first approximation of the mode shapes. The natural frequencies were estimated by the transfer matrix method (TMM) and finite element method (FEM) in order to compare the proposed model results with well-founded numerical methods.","PeriodicalId":49185,"journal":{"name":"International Journal of Acoustics and Vibration","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67722283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0