Vibration最新文献_第3页

Quadruped Rotary Galloping Gait Pattern within a Constant Radius Bend Using Accelerometry 使用加速度计在恒定半径弯曲内的四足旋转疾驰步态模式

Vibration Pub Date : 2023-09-20 DOI: 10.3390/vibration6030044

David Eager, Imam Hossain, Callan Brook

引用次数: 0

Vibrational Effects on the Acoustic Performance of Multi-Layered Micro-Perforated Metamaterials 振动对多层微穿孔超材料声学性能的影响

Vibration Pub Date : 2023-09-17 DOI: 10.3390/vibration6030043

Cédric Maury, Teresa Bravo

{"title":"Vibrational Effects on the Acoustic Performance of Multi-Layered Micro-Perforated Metamaterials","authors":"Cédric Maury, Teresa Bravo","doi":"10.3390/vibration6030043","DOIUrl":"https://doi.org/10.3390/vibration6030043","url":null,"abstract":"Broadband noise reduction over the low–mid frequency range in the building and transportation sectors requires compact lightweight sound absorbers of a typical subwavelength size. The use of multi-layered, closely spaced (micro-)perforated membranes or panels, if suitably optimized, contributes to these objectives. However, their elasticity or modal behaviors often impede the final acoustical performance of the partition. The objective of this study is to obtain insights into the vibrational effects induced by elastic limp membranes or panel volumetric modes on the optimized sound absorption properties of acoustic fishnets and functionally graded partitions (FGP). The cost-efficient global optimization of the partitions’ frequency-averaged dissipation is achieved using the simulated annealing optimization method, while vibrational effects are included through an impedance translation method. A critical coupling analysis reveals how the membranes or panel vibrations redistribute the locations of the Hole-Cavity resonances, as well as their cross-coupling with the panels’ first volumetric mode. It is found that elastic limp micro-perforated membranes broaden the pass-band of acoustic fishnets, while smoothing out the dissipation ripples over the FGP optimization bandwidth. Moreover, the resonance frequency of the first panels mode sets an upper limit to the broadband optimization of FGPs, up to which a high dissipation, high absorption, and low transmission can be achieved.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135259415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Using Wearable Accelerometers to Develop a Vertical Ground Reaction Force Prediction Model during Running: A Sensitivity Study 利用可穿戴式加速度计建立跑步过程中垂直地面反作用力预测模型:敏感性研究

Vibration Pub Date : 2023-09-12 DOI: 10.3390/vibration6030042

Thomas Provot, Samaneh Choupani, Maxime Bourgain, Laura Valdes-Tamayo, Delphine Chadefaux

{"title":"Using Wearable Accelerometers to Develop a Vertical Ground Reaction Force Prediction Model during Running: A Sensitivity Study","authors":"Thomas Provot, Samaneh Choupani, Maxime Bourgain, Laura Valdes-Tamayo, Delphine Chadefaux","doi":"10.3390/vibration6030042","DOIUrl":"https://doi.org/10.3390/vibration6030042","url":null,"abstract":"The estimation of vertical ground reaction forces (VGRFs) during running is necessary to understand running mechanisms. For this purpose, the use of force platforms is fundamental. However, to extend the study of VGRFs to real conditions, wearable accelerometers are a promising alternative to force platforms, whose use is often limited to the laboratory environment. The objective of this study was to develop a VGRF model using wearable accelerometers and a stepwise regression algorithm. Several models were developed and validated using the VGRFs and acceleration signals collected during 100 stances performed by one participant. The validated models were tested on eight participants. In a sensitivity study, the strongest correlations were observed at cut-off frequencies of ≤25 Hz and in models developed with 30 to 90 stances. After the validation phase, the 10 best models had, on average, low relative differences (≤10%) in the estimation of discrete VGRF parameters, i.e., the passive peak (εpp=6.26%), active peak (εap=2.22%), and loading rate (εlr=2.17%). The results indicate that the development of personalized models is more suitable for achieving the best estimates. The proposed methodology opens many perspectives for monitoring VGRFs under real conditions using a limited number of wearable sensors.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135827793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation on the Rotordynamic Characteristics of Turbopumps with Angular Contact Ball Bearings 角接触球轴承涡轮泵转子动力学特性研究

Vibration Pub Date : 2023-08-28 DOI: 10.3390/vibration6030041

Yue Su, Kaifu Xu, Yongqiang Gao, Lu Jin

引用次数: 0

Focal Muscle Vibration (fMV) for Post-Stroke Motor Recovery: Multisite Neuroplasticity Induction, Timing of Intervention, Clinical Approaches, and Prospects from a Narrative Review 脑卒中后运动恢复的局灶性肌肉振动(fMV):多位点神经可塑性诱导、干预时机、临床方法和前景

Vibration Pub Date : 2023-08-08 DOI: 10.3390/vibration6030040

A. Viganó, C. Celletti, G. Giuliani, T. B. Jannini, F. Marenco, I. Maestrini, Rosaceleste Zumpano, E. Vicenzini, M. Altieri, F. Camerota, V. Di Piero, M. Toscano

{"title":"Focal Muscle Vibration (fMV) for Post-Stroke Motor Recovery: Multisite Neuroplasticity Induction, Timing of Intervention, Clinical Approaches, and Prospects from a Narrative Review","authors":"A. Viganó, C. Celletti, G. Giuliani, T. B. Jannini, F. Marenco, I. Maestrini, Rosaceleste Zumpano, E. Vicenzini, M. Altieri, F. Camerota, V. Di Piero, M. Toscano","doi":"10.3390/vibration6030040","DOIUrl":"https://doi.org/10.3390/vibration6030040","url":null,"abstract":"Despite newly available therapies for acute stroke and innovative prevention strategies, stroke remains the third leading cause of disability-adjusted life-years (DALYs) lost worldwide, mostly because more than half of stroke survivors aged 65 and over exhibit an incomplete functional recovery of the paretic limb. Given that a repeated sensory input is one of the most effective modulators of cortical motor and somatosensory structures, focal muscle vibration (fMV) is gaining growing interest as a safe, well-tolerated, and non-invasive brain stimulation technique to promote motor recovery after stroke with a long-lasting and clinically relevant improvement in strength, step symmetry, gait, and kinematics parameters. In this narrative review, we first summarize the structural (neural plasticity) and functional changes (network relearning) triggered by the stroke lesion and carried out at a brain and spinal cord level in an attempt to recover from the loss of function. Then, we will focus on the fMV’s plasticity-based mechanisms reporting evidence of a possible concurrently acting multisite plasticity induced by fMV. Finally, to understand what the most effective fMV rehabilitation protocol could be, we will report the most recent evidence regarding the different clinical approaches and timing of the fMV treatment, the related open issues, and prospects.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48182275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vibration Measurements by Self-Mixing Interferometry: An Overview of Configurations and Benchmark Performances 自混合干涉振动测量:配置和基准性能概述

Vibration Pub Date : 2023-08-02 DOI: 10.3390/vibration6030039

S. Donati

{"title":"Vibration Measurements by Self-Mixing Interferometry: An Overview of Configurations and Benchmark Performances","authors":"S. Donati","doi":"10.3390/vibration6030039","DOIUrl":"https://doi.org/10.3390/vibration6030039","url":null,"abstract":"Self-mixing interferometry (SMI) is suitable to sense and measure vibrations of amplitudes ranging from picometers to millimeters at frequencies from sub-Hz to MHz’s. As an optical probe, SMI has the advantage of being non-invasive with the ability to measure without any treatment of the target surface and operate from a substantial standoff distance from the target. As an additional advantage, the SMI configuration is much simpler than that of conventional interferometers as it does not require any optical part external to the laser source. After a short introduction to the basics of SMI, we review the development of configurations of SMI instruments for vibration measurements, based on both analog and digital processing, with record performance to cover the range of vibration amplitudes from 0.1 nm to 1 mm, frequencies up to MHz, and stand-off distances up to 100 m. These performances set a benchmark that is unequaled by other approaches reported so far in the literature. The configurations we describe are (i) a simple MEMS-response testing instrument based on fringe counting, (ii) a half-fringe locking vibrometer for mechanical mode analysis and transfer function measurements, with a wide linear response on six decades of amplitude, (iii) a vibrometer with analog switching cancellation for μm-to-mm amplitude of vibrations, and (iv) a long standoff distance vibrometer for testing large structures at distances up to 100 m and with nm sensitivity. Lastly, as the vibrometer will almost invariably operate on untreated, diffusing surfaces, we provide an evaluation of phase-induced speckle pattern errors affecting the SMI measurement.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42663921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Uncertainty Propagation and Global Sensitivity Analysis of a Surface Acoustic Wave Gas Sensor Using Finite Elements and Sparse Polynomial Chaos Expansions 基于有限元和稀疏多项式混沌展开的声表面波气体传感器不确定度传播和全局灵敏度分析

Vibration Pub Date : 2023-08-01 DOI: 10.3390/vibration6030038

M. Hamdaoui

引用次数: 0

Residual Shift of Vibrotactile Perception Thresholds Following Repeated Hand-Arm Vibration Exposure: Screening Parameter for Early Signs of Neurosensory Disorders 重复手臂振动暴露后振动触觉感知阈值的残余移位:神经感觉障碍早期体征的筛选参数

Vibration Pub Date : 2023-08-01 DOI: 10.3390/vibration6030037

N. Shibata

{"title":"Residual Shift of Vibrotactile Perception Thresholds Following Repeated Hand-Arm Vibration Exposure: Screening Parameter for Early Signs of Neurosensory Disorders","authors":"N. Shibata","doi":"10.3390/vibration6030037","DOIUrl":"https://doi.org/10.3390/vibration6030037","url":null,"abstract":"Background: The purpose of this study was to validate the applicability of a new screening parameter of VPTW defined as the difference between the ascending and descending thresholds of vibrotactile perception to evaluation of the increasing risk of the neurological components of hand-arm vibration syndrome (HAVS) for repeated exposure to hand-arm vibration (HAV). Methods: Thirty subjects—10 old exposed (G1), 10 old non-exposed (G2), and 10 young non-exposed subjects (G3)—were required to carry out three 3 min grip tasks with exposure to two intensities of HAV at 10 min intervals. Vibration perception measurements, each of which lasted 90 s, were performed at 5 min intervals at the right index finger. Results: VPTWs calculated from pairs of the vibrotactile ascending and descending thresholds at the fingertips were not significantly affected by repeated HAV exposure. Moreover, the VPTWs measured for non-exposed subjects were almost invariant regardless of the subjects’ age or the time elapsed after repeated exposure to HAV. Residual TTSs at 125 Hz gradually recovered in all subject groups under both HAV exposure conditions. The residual TTSs of non-exposed subject groups significantly increased as the number of iterations of HAV exposure increased. Conclusions: VPTWs measured after exposure to repeated HAV are invariant and independent of the individual neurosensory characteristics of the fingertips, which supports the hypothesis that VPTWs can be used as a screening parameter to detect potential patients only with neurosensory components observed as early signs of HAVS.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43445991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Application of Micro-Vibratory Phenomena of a Shape-Memory Alloy Wire to a Novel Vibrator 形状记忆合金丝微振动现象在新型振动器中的应用

Vibration Pub Date : 2023-07-26 DOI: 10.3390/vibration6030036

Takashi Chujo, H. Sawada

{"title":"The Application of Micro-Vibratory Phenomena of a Shape-Memory Alloy Wire to a Novel Vibrator","authors":"Takashi Chujo, H. Sawada","doi":"10.3390/vibration6030036","DOIUrl":"https://doi.org/10.3390/vibration6030036","url":null,"abstract":"The widespread use of smartphones and smart wearable devices has created a great demand for vibrators with complex vibration patterns driven by simple circuits. In our previous studies, we observed that a filiform shape-memory alloy (SMA) wire will shrink and then return to its initial length, perfectly synchronizing with a given pulse current. Here, we developed a novel vibrator whose structure allows the micro-vibrations of an SMA wire to be amplified up to a recognizable level without directly touching the wire. The vibrator has the advantage of independently controlling its magnitude and frequency together with a simple driving circuit since it is directly driven by a frequency-modulated pulse current with a controlled duty ratio. We measured the power consumption and the acceleration generated by the vibrator. The results showed that the vibrator consumed only 4–77 milliwatts of power with a quick vibration response within 5 milliseconds, and the acceleration increased significantly in a duty ratio range of around 1%. Furthermore, user evaluations demonstrated that differences in the magnitude and frequency of the generated vibrations were sufficiently recognized when the vibrator was driven by different duty ratios and frequencies, and the vibrator provided various tactile and haptic sensations to users.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47112693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Internal Boundary Layers and Sensitivity on Frequency Response of Shells of Revolution 内边界层和灵敏度对旋转壳体频率响应的影响

Vibration Pub Date : 2023-07-18 DOI: 10.3390/vibration6030035

H. Hakula

引用次数: 0