Vibration最新文献_第9页

Co-Simulation-Based Verification of Torsional Vibration Protection of Electric-Driven Railway Vehicle Wheelsets 基于联合仿真的电动轨道车辆轮对扭振防护验证

Vibration Pub Date : 2022-09-08 DOI: 10.3390/vibration5030036

A. Abouzeid, F. Trimpe, Sönke Lück, M. Traupe, J. Guerrero, F. Briz

引用次数: 2

On the Efficiency Enhancement of an Actively Tunable MEMS Energy Harvesting Device 关于提高主动可调谐MEMS能量采集装置的效率

Vibration Pub Date : 2022-09-06 DOI: 10.3390/vibration5030035

M. Aliasghary, S. Azizi, H. Madinei, H. Haddad Khodaparast

{"title":"On the Efficiency Enhancement of an Actively Tunable MEMS Energy Harvesting Device","authors":"M. Aliasghary, S. Azizi, H. Madinei, H. Haddad Khodaparast","doi":"10.3390/vibration5030035","DOIUrl":"https://doi.org/10.3390/vibration5030035","url":null,"abstract":"In this paper, we propose an active control method to adjust the resonance frequency of a capacitive energy harvester. To this end, the resonance frequency of the harvester is tuned using an electrostatic force, which is actively controlled by a voltage source. The spring softening effect of the electrostatic force is used to accommodate the dominant frequency of the ambient mechanical vibration within the bandwidth of the resonance region. A single degree of freedom is considered, and the nonlinear equation of motion is numerically integrated over time. Using a conventional proportional–integral–derivative (PID) control mechanism, the results demonstrated that our controller could shift the resonance frequency leftward on the frequency domain and, as a result, improve the efficiency of the energy harvester, provided that the excitation frequency is lower than the resonance frequency of the energy harvester. Application of the PID controller in the resonance zone resulted in pull-in instability, adversely affecting the harvester’s performance. To tackle this problem, we embedded a saturation mechanism in the path of the control signal to prevent a sudden change in motion amplitude. Outside the pull-in band, the saturation of the control signal resulted in the reduction of harvested power compared to the non-saturated signal; this is a promising improvement in the design and analysis of energy harvesting devices.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41776967","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: 1

Vibration Analysis of a 5-DOF Long-Reach Robotic Arm 五自由度长臂机械臂振动分析

Vibration Pub Date : 2022-09-03 DOI: 10.3390/vibration5030034

H. Badkoobehhezaveh, R. Fotouhi, Qianwei Zhang, D. Bitner

{"title":"Vibration Analysis of a 5-DOF Long-Reach Robotic Arm","authors":"H. Badkoobehhezaveh, R. Fotouhi, Qianwei Zhang, D. Bitner","doi":"10.3390/vibration5030034","DOIUrl":"https://doi.org/10.3390/vibration5030034","url":null,"abstract":"In this paper, dynamic and vibration characteristics of a newly developed 5-degrees-of-freedom (5-DOF) long-reach robotic arm for farm applications is studied through finite element analysis (FEA), as well as experimentally. The new manipulator is designed to be light and compact enough that it can be mounted on a small vehicle for farm applications. A finite element model of this novel manipulator was established using a commercial FEA software. FEA was carried out for two different configurations of the manipulator (fully-extended and vertical half-extended). The fully-extended configuration provides the longest reach of the arm and is one of the most commonly used poses in farm applications; vibrations of this configuration are highly affected by its base excitation. The FEA results indicated that the first six natural frequencies of the manipulator for the two configurations considered were between 4.4 to 41.6 (Hz). Modal analysis on the fully-extended configuration was completed using experimental modal analysis to verify the finite element results. In the experiments, acceleration data were obtained utilizing sensors, and were post-processed using Fast-Fourier Transforms. The first six natural frequencies and their corresponding mode shapes were obtained using FEA and also experimentally, and the results were compared; the comparison showed good agreement, with less than 10% difference. Our verified FE model provides a reliable basis for future vibration control for the newly developed robotic arm for different applications. A harmonic response simulation was also carried out using an experimentally corrected FE model; this provides a good understanding of the dynamic behavior of the newly developed arm under base excitation. This paper offers an experimentally corrected FEA model for a large manipulator with base excitation for farm applications.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43691216","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: 3

Parametric Instability of Functionally Graded Porous Cylindrical Panels under the Effect of Static and Time-Dependent Axial Loads 静态和时变轴向载荷作用下梯度多孔圆柱板的参数不稳定性

Vibration Pub Date : 2022-09-02 DOI: 10.3390/vibration5030033

Salah M. Zaidan, Hama M. Hasan

{"title":"Parametric Instability of Functionally Graded Porous Cylindrical Panels under the Effect of Static and Time-Dependent Axial Loads","authors":"Salah M. Zaidan, Hama M. Hasan","doi":"10.3390/vibration5030033","DOIUrl":"https://doi.org/10.3390/vibration5030033","url":null,"abstract":"This work presents an analytical study of the parametric instability of cylindrical panels containing functionally graded porous exposed to static and dynamic periodic axial loads under simply supported boundary conditions. Based on Hamilton’s principle, the governing equation of motion by using first-order shear deformation theory (FSDT) has been obtained. By applying the Galerkin technique, an excitation frequency expression is derived, which helps identify areas of instability of functionally graded porous cylindrical panels. Numerical simulations are used to validate the analytical results. Eventually, the impacts of the porosity coefficient, porosity distribution method, static and dynamic periodic axial loads, panel angle, circumferential wave number, and cylindrical panel characteristics on the region of instability are displayed in the section of results and discussions. The findings show that when the porosity is further from the surface, the more stable the structure is. Furthermore, a small angle of the cylindrical panels gives a better dynamic response than a large angle. In addition, increased static and dynamic loads lead to an expansion of areas of instability.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49622803","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: 1

Progressive Collapse of Buildings 建筑物的渐进式倒塌

Vibration Pub Date : 2022-09-01 DOI: 10.3390/vibration5030032

C. Dimopoulos, C. Gantes

引用次数: 1

Deep Machine Learning for Acoustic Inspection of Metallic Medium 金属介质声学检测的深度机器学习

Vibration Pub Date : 2022-08-28 DOI: 10.3390/vibration5030030

B. Jarreau, S. Yoshida, Emily Laprime

{"title":"Deep Machine Learning for Acoustic Inspection of Metallic Medium","authors":"B. Jarreau, S. Yoshida, Emily Laprime","doi":"10.3390/vibration5030030","DOIUrl":"https://doi.org/10.3390/vibration5030030","url":null,"abstract":"Acoustic non-destructive testing is widely used to detect signs of damage. However, an experienced technician is typically responsible for interpreting the result, and often the evaluation varies depending on the technician’s opinion. The evaluation is especially challenging when the acoustic signal is analyzed in the near field as Fresnel range diffraction complicates the data. In this study, we propose a Convolutional Neural Network (CNN) algorithm to detect anomalies bearing in mind its future application to micro-scale specimens such as biomedical materials. Data are generated by emitting a continuous sound wave at a single frequency through a metal specimen with a sub-millimeter anomaly and collecting the transmitted signal at several lateral locations on the opposite side (the observation plane) of the specimen. The distance between the anomaly and the observation plane falls in the quasi Fresnel diffraction regime. The use of transmitted signals is essential to evaluate the phase shift due to the anomaly, which contains information about the substance in the anomaly. We have developed a seven-layered CNN to analyze the acoustic signal in the frequency domain. The CNN takes spectrograms representing the change in the amplitude and phase of the Fourier transform over the lateral position on the observation plane as input and classifies the anomaly into nine classes in association with the lateral location of the anomaly relative to the probing signal and the material of the anomaly. The CNN performed excellently demonstrating the validation accuracy as high as 99.9%. This result clearly demonstrates CNN’s ability to extract features in the input signal that are undetectable to humans.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48179508","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: 2

Vertical and Side-Alternating Whole Body Vibration Platform Parameters Influence Lower Extremity Blood Flow and Muscle Oxygenation 垂直和侧向交替的全身振动平台参数对下肢血流和肌肉氧合的影响

Vibration Pub Date : 2022-08-28 DOI: 10.3390/vibration5030031

Kaitlin Lyons, Aaron G Parks, Oluwagbemiga D. Dadematthews, Paige A McHenry, J. Sefton

{"title":"Vertical and Side-Alternating Whole Body Vibration Platform Parameters Influence Lower Extremity Blood Flow and Muscle Oxygenation","authors":"Kaitlin Lyons, Aaron G Parks, Oluwagbemiga D. Dadematthews, Paige A McHenry, J. Sefton","doi":"10.3390/vibration5030031","DOIUrl":"https://doi.org/10.3390/vibration5030031","url":null,"abstract":"This study directly compared blood flow and oxygenation during six treatment parameters used with vertical and side alternating whole body vibration (WBV). Twenty-seven healthy adults were randomized into the vertical or side-alternating (vibration type) WBV group. Participants completed three WBV sessions a week apart, 5 sets of 1 min on/off, at 3 conditions (Vertical: 30 Hz and 4 mm, 40 Hz and 2 mm, 45 Hz and 4 mm; Side-alternating: 10 Hz and 4 mm, 18 Hz and 3 mm and 26 Hz and 2 mm). Blood flow velocity and popliteal artery diameter, muscle oxygenation, skin temperature, heart rate and blood pressure were assessed. Muscle oxygenation was significantly increased for all vibration frequencies and types following two minutes of WBV (14.78%, p = 0.02) and continued until immediately after the cessation of WBV (24.7%, p < 0.001). WBV also increased heart rate (23.9%, p < 0.001) and systolic blood pressure (8.9%, p < 0.001) regardless of frequency and vibration type. Side-alternating and vertical WBV increased muscle oxygenation and heart rate in healthy participants completing an isometric squat. Muscle oxygenation was not increased until the second vibration set indicating the amount of time spent on the platform may have a significant effect on increases in blood flow.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42224729","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

Topological Acoustic Sensing Using Nonseparable Superpositions of Acoustic Waves 利用声波不可分离叠加的拓扑声学传感

Vibration Pub Date : 2022-08-25 DOI: 10.3390/vibration5030029

T. Lata, P. Deymier, K. Runge, William Clark

引用次数: 0

Research on Impact Attenuation Characteristics of Greyhound Racing Track Padding for Injury Prevention 灰狗赛道衬垫防伤冲击衰减特性研究

Vibration Pub Date : 2022-08-04 DOI: 10.3390/vibration5030028

D. Eager, Shi Zhou, I. Hossain, Karlos Ishac, B. Halkon

{"title":"Research on Impact Attenuation Characteristics of Greyhound Racing Track Padding for Injury Prevention","authors":"D. Eager, Shi Zhou, I. Hossain, Karlos Ishac, B. Halkon","doi":"10.3390/vibration5030028","DOIUrl":"https://doi.org/10.3390/vibration5030028","url":null,"abstract":"To reduce injuries to greyhounds caused by collisions with fixed racing track objects such as the outside fence or the catching pen structures, padding systems are widely adopted. However, there are currently neither recognised standards nor minimum performance thresholds for greyhound industry padding systems. This research is the first of its kind to investigate the impact attenuation characteristics of different padding systems for use within the greyhound racing industry for the enhanced safety and welfare of racing greyhounds. A standard head injury criterion (HIC) meter was used to examine padding impact attenuation performance based on the maximum g-force, HIC level and the HIC duration. Initially, greyhound racing speed was recorded and analysed with the IsoLynx system to understand the potential impact hazard to greyhounds during racing which indicates the necessity for injury prevention with padding. A laboratory test was subsequently conducted to compare the impact attenuation performance of different kinds of padding. Since padding impact attenuation characteristics are also affected by the installation and substrate, onsite testing was conducted to obtain the padding system impact attenuation performance in actual greyhound racing track applications. The test results confirm that the padding currently used within the greyhound industry is adequate for the fence but inadequate when used for rigid structural members such as the catching pen gate supports. Thus, increasing the padding thickness is strongly recommended if it is used at such locations. More importantly, it is also recommended that, after the installation of padding on the track, its impact attenuation characteristics be tested according to the methodology developed herein to verify the suitability for protecting greyhounds from injury.","PeriodicalId":75301,"journal":{"name":"Vibration","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49167446","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: 1

Nonlinear Piezoelectric Energy Harvester: Experimental Output Power Mapping 非线性压电能量采集器：实验输出功率映射

Vibration Pub Date : 2022-07-27 DOI: 10.3390/vibration5030027

I. Burda

引用次数: 2