March 16最新文献_第5页

Can we find active noise control in everyday life soon? 我们能很快在日常生活中找到主动噪声控制吗?

March 16 Pub Date : 2019-03-01 DOI: 10.20855/IJAV.2019.24.1E91

M. Pawełczyk

引用次数: 0

Vibration-Based Non-Destructive Evaluation of Internal Damage in Foam Cored Sandwich Structures Using Wavelet Analysis 基于小波分析的泡沫芯夹层结构内部损伤振动无损评价

March 16 Pub Date : 2019-03-01 DOI: 10.20855/ijav.2019.24.11140

A. Katunin

{"title":"Vibration-Based Non-Destructive Evaluation of Internal Damage in Foam Cored Sandwich Structures Using Wavelet Analysis","authors":"A. Katunin","doi":"10.20855/ijav.2019.24.11140","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.11140","url":null,"abstract":"Modern mechanical and civil structures are increasingly designed using polymeric composites that ensure great\u0000strength-to-mass ratio and are resistant to various environmental interactions, like corrosion. The application of\u0000sandwich structures in the design of mechanical and civil constructions is determined by their good stiffness properties and very low mass, which is a very attractive combination. Due to their wide applicability, these structures\u0000should be properly maintained and diagnosed, and thus, appropriate non-destructive testing (NDT) methods should\u0000be developed in order to detect and identify various types of damage. Special attention should be paid to internal\u0000damage (damage to the core of a sandwich structure), which cannot be detected during a visual inspection. In the\u0000paper, an NDT method based on modal analysis and further processing of modal shapes using a wavelet transform is proposed. Three sandwich structures with damage to the core of various types were experimentally tested\u0000using modal analysis, the damage positions were detected and identified using wavelet analysis, and verified by\u0000comparing the results of previously performed thermographic tests. The obtained results show a high effectiveness\u0000of the proposed approach, which could find an application in the industrial inspection of sandwich structures in a\u0000non-destructive and non-contact manner.","PeriodicalId":18217,"journal":{"name":"March 16","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86085883","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

Using a New Size Dependent Orthotropic Elastic Shell Model for the Investigation of Free Vibration of Protein Microtubules 用一种新的尺寸相关的正交各向异性弹性壳模型研究蛋白质微管的自由振动

March 16 Pub Date : 2019-03-01 DOI: 10.20855/IJAV.2019.24.11263

Y. Beni, M. K. Zeverdejani

引用次数: 5

Study on Acoustic Performance of a Water Muffler for Gear Pump 齿轮泵水消声器的声学性能研究

March 16 Pub Date : 2019-03-01 DOI: 10.20855/IJAV.2019.24.11143

T. Du, Ning Chu, Linlin Cao, T. Miao, Dazhuan Wu

{"title":"Study on Acoustic Performance of a Water Muffler for Gear Pump","authors":"T. Du, Ning Chu, Linlin Cao, T. Miao, Dazhuan Wu","doi":"10.20855/IJAV.2019.24.11143","DOIUrl":"https://doi.org/10.20855/IJAV.2019.24.11143","url":null,"abstract":"A water muffler is used for the noise control of a hydraulic pipeline with an external gear pump. An experimental system is established to investigate the acoustic performance of the water muffler, in which the gear pump is utilized as the sound source and power supply. Comparisons between the experimental results of the reference tube, rubber tube, and water mufflers with different inner structures have been made. Numerical simulations on the rubber tube and different water mufflers with various inner structures have been conducted. Simulation results have been compared with the experimental results. These comparison results show that the rubber tube with a compliant wall substantially contributes to the reduction of the noise generated by the gear pump, especially at the high frequency band and relatively low rotate speed of the gear pump. The water muffler results in the enhancement of the noise reduction effect on the rubber tube. With the speed of the gear pump increasing from 1172 r/min to 2344 r/min, the effect of the noise reduction becomes much weaker, since the flow-induced noise gets more intensified. For the rubber tube, in particular, the sound pressure level gets close to that of the reference tube at the speed of 2344 r/min. Moreover, it has been proven by another important experimental result that the length of the inner structure can play a critical role to the flow noise generation.","PeriodicalId":18217,"journal":{"name":"March 16","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81196279","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

Higher-Order Overtone Thickness-Shear Vibrations of Multilayered Thin-Film Acoustic Wave Resonators and Angular Rate Sensing 多层薄膜声波谐振器的高阶泛音厚度-剪切振动及角速率传感

March 16 Pub Date : 2019-03-01 DOI: 10.20855/IJAV.2019.24.11147

Hui Chen, Ji Wang, Jianke Du, Jia-shi Yang

{"title":"Higher-Order Overtone Thickness-Shear Vibrations of Multilayered Thin-Film Acoustic Wave Resonators and Angular Rate Sensing","authors":"Hui Chen, Ji Wang, Jianke Du, Jia-shi Yang","doi":"10.20855/IJAV.2019.24.11147","DOIUrl":"https://doi.org/10.20855/IJAV.2019.24.11147","url":null,"abstract":"We propose a new structure for piezoelectric gyroscopes. It is made from multilayered thin films of AlN or ZnO\u0000with alternating c-axes along the film thickness. It is shown theoretically that when such a film is electrically\u0000driven into higher-order overtone thickness-shear vibration in one of the two in-plane directions of the film and\u0000is rotating about the film normal, the Coriolis force due to the rotation causes a higher-order overtone thicknessshear vibration in a perpendicular direction with an electrical output that can be used to measure the angular rate\u0000of the rotation. Different from existing thickness-shear mode piezoelectric gyroscopes which are based on the\u0000fundamental or the second overtone thickness-shear mode, the proposed gyroscope operates with higher-order\u0000overtone thickness-shear modes with higher frequencies and hence potentially higher sensitivity. Because of the\u0000overtone modes, the Coriolis force acting on the gyroscope forms a self-equilibrated system and does not transmit\u0000a net force or torque to the mounting structure. This implies higher device quality factor and better performance.","PeriodicalId":18217,"journal":{"name":"March 16","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90965938","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

Unbalance Rotor Parameters Detection Based on Artificial Neural Network 基于人工神经网络的不平衡转子参数检测

March 16 Pub Date : 2019-03-01 DOI: 10.20855//ijav.2019.24.11272

M. Gohari, A. Kord, H. Jalali

引用次数: 6

Seat to Head Transmissibility during Exposure to Vertical Seat Vibration: Effects of Posture and Vibration Magnitude 暴露于垂直座椅振动时，座椅到头部的传导率:姿势和振动幅度的影响

March 16 Pub Date : 2019-03-01 DOI: 10.20855/ijav.2019.24.11108

M. Bhiwapurkar, V. Saran, S. Harsha

{"title":"Seat to Head Transmissibility during Exposure to Vertical Seat Vibration: Effects of Posture and Vibration Magnitude","authors":"M. Bhiwapurkar, V. Saran, S. Harsha","doi":"10.20855/ijav.2019.24.11108","DOIUrl":"https://doi.org/10.20855/ijav.2019.24.11108","url":null,"abstract":"The low frequency vibration transmitted to the body can affect the comfort, performance, and health of humans. In\u0000this paper, the effect of variations in posture and vibration magnitude on the head motion in three translational axes\u0000(fore-and-aft, lateral and vertical) has been studied with a vertical seat vibration. Thirty healthy male subjects were\u0000exposed to random vibration with three vibration magnitudes of 0.4, 0.8, and 1.2 m/s2\u0000rms over the frequency range\u0000of 1–20 Hz. The results are analysed in terms of seat-to-head-transmissibility (STHT) for the head motions in two\u0000seated postures (backrest and leaning forward on table). The measurement of the head motion was made with an\u0000apparatus (bite-bar) specifically developed for this purpose. The measured responses to a single axis seat vibration\u0000have also shown notable cross-axis responses in both vertical and fore-and-aft axes for both postures. The crossaxis fore-aft and vertical STHT responses showed single peak near 5 Hz in both postures. An increasing intensity\u0000of vibration yields a non-linear softening effect in the muscle tension, particularly in the presence of back support,\u0000however, the body stiffens under a greater upper body motion in the forward leaning posture. The combined effect\u0000of the unsupported back and hands support was observed to be more pronounced around the resonance peak in the\u0000forward lean posture.","PeriodicalId":18217,"journal":{"name":"March 16","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74245754","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

On the Stabilization of a Vertical Bloch Line Fair in a Domain Wall in an Ion-Implanted Garnet Film 离子注入石榴石薄膜中畴壁上垂直斑点线的稳定

March 16 Pub Date : 1988-12-31 DOI: 10.1515/9783112480823-027

R. Kosinski

引用次数: 0

Influence of Mg Doping and Composition on the Light-Induced Charge Transport in LiNbO2 Mg掺杂及组成对LiNbO2光致电荷输运的影响

March 16 Pub Date : 1988-12-31 DOI: 10.1515/9783112480823-012

R. Sommerfeldt, L. Holtmann, E. Krätzig, B. C. Grabmaier

引用次数: 0

Influence of Interface States on the Electrical Properties 21 of Mg-Zn3P2 Junctions 界面状态对Mg-Zn3P2结电性能的影响

March 16 Pub Date : 1988-12-31 DOI: 10.1515/9783112480823-043

J. Szatkowski, K. Sieraňski

引用次数: 0