The International Journal of Acoustics and Vibration最新文献_第9页

Determination of the Fundamental Lateral Bending Mode Frequency of a Spacecraft from its Static Deflection 从航天器的静态偏转确定其基本侧向弯曲模态频率

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.11822

K. Renji, C. Varghese, I. Kumar

{"title":"Determination of the Fundamental Lateral Bending Mode Frequency of a Spacecraft from its Static Deflection","authors":"K. Renji, C. Varghese, I. Kumar","doi":"10.20855/ijav.2022.27.11822","DOIUrl":"https://doi.org/10.20855/ijav.2022.27.11822","url":null,"abstract":"The primary structure of a spacecraft that involves the central cylinder is designed to meet a specific value of fundamental lateral mode frequency. Though this frequency can be theoretically estimated by using a finite element model, its experimental verification is only possible when the entire spacecraft is made ready. However, static load tests are done on the primary structure of the spacecraft as soon as the structure is realized. In this work, a methodology to determine the fundamental bending mode frequency of a spacecraft from the deflections measured when the structure alone is subjected to static load tests is developed. An expression relating the fundamental lateral bending mode frequency of a spacecraft, having several masses attached at different locations, and the deflection at its tip is derived. Two spacecraft, one of 3000kg class and the other of 6000kg class are taken as examples. The fundamental lateral frequencies are determined using this methodology. These frequencies are also obtained through resonance search tests. It is shown that the derived expression will be very useful in estimating the fundamental lateral mode frequency of a spacecraft with the help of the measured deflection.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130601255","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

Book Reviews: Acoustics for Engineers (Ning Xiang and Jens Blauert) 书评:工程师声学(Ning Xiang, Jens Blauert)

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.1br

Jian Kang

引用次数: 0

Transport Theory Approach to Phase Transition-Turbulence as an Example 相变的输运理论研究——以湍流为例

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.1e103

W. Gan

引用次数: 0

Instantaneous Frequency Estimation Method for the Vibration Signal of Rotating Machinery Based on STFTSC Algorithm 基于STFTSC算法的旋转机械振动信号瞬时频率估计方法

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.11842

Bin Wu, Shaojie Wang, Liang Hou, Xiangjian Bu, Chunhua Chen, Zheng‐Ru Yang

{"title":"Instantaneous Frequency Estimation Method for the Vibration Signal of Rotating Machinery Based on STFTSC Algorithm","authors":"Bin Wu, Shaojie Wang, Liang Hou, Xiangjian Bu, Chunhua Chen, Zheng‐Ru Yang","doi":"10.20855/ijav.2022.27.11842","DOIUrl":"https://doi.org/10.20855/ijav.2022.27.11842","url":null,"abstract":"In this paper, an instantaneous frequency identification method known as STFTSC is developed by combining short-time Fourier transformation and the seam carving (SC) algorithm (widely used in image processing). In this method, the STFT is applied to analyze the time-frequency energy distribution of a vibration signal under variable-speed conditions. Subsequently, the energy gradient is calculated through the Sobel operator based on the time-frequency energy distribution. The energy gradient distribution contains multiple ridges, which are corresponding instantaneous frequencies of different orders. Finally, the targeted ridge extraction is transformed into an optimization problem, and the dynamic programming algorithm (DP) is used to search the targeted ridge with the minimum energy gradient to estimate the instantaneous frequency. The effectiveness of the proposed method is validated by a simulation experiment, moreover, a rotating machinery fault simulation test bench is employed to validate the method, which is then compared with polynomial chirplet transformation (PCT) and analyzed during the test process. The results show that the STFTSC instantaneous frequency estimation algorithm has a higher extraction accuracy and better application value in engineering problems than the PCT.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115146693","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

Modeling and Analysis of Active Full Vehicle Suspension Model Optimized Using the Advanced Fuzzy Logic Controller 基于先进模糊控制器优化的整车主动悬架模型建模与分析

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.11825

Shailendra Kumar, A. Medhavi, Raghuvir Kumar, P. Mall

{"title":"Modeling and Analysis of Active Full Vehicle Suspension Model Optimized Using the Advanced Fuzzy Logic Controller","authors":"Shailendra Kumar, A. Medhavi, Raghuvir Kumar, P. Mall","doi":"10.20855/ijav.2022.27.11825","DOIUrl":"https://doi.org/10.20855/ijav.2022.27.11825","url":null,"abstract":"The suspension system plays a major role in automobiles to improve passenger comfort, passenger safety and road handling. It isolates the body of a vehicle from road disturbances. The full vehicle would be subjected to disturbances from all four wheels or a full suspension model of the vehicle and, thus, a full-suspension model of the vehicle should be added to the idea of an enhanced control preview. The input data for the fuzzy logic controller (FLC) is the velocity and acceleration of the front and rear wheels. Controller outputs are considered to be active forces that improve driver comfort, safety and road handling characteristics. The objective of this work is to model and analyse an active full vehicle suspension. The model is optimized using advanced FLC to improve driver comfort, safety and road handling. The mathematical model for the active full vehicle suspension model has been derived. The necessary background for the Simulink fuzzy logic and FLC has been presented. All the simulations are carried out using MATLAB/SIMULINK, a high-performance numeric computation and visualization software package. The fuzzy logic-controlled active values have been compared with ordinary passive simulated values for road profiles. The result of the simulation show that the designed advanced FLC has improved ride comfort by effectively reducing the vehicle body displacement. There is also an appreciable reduction in velocity and acceleration with no increase in suspension travel.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124666470","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

Research on Underwater Acoustic Target Depth Classification Based on Modal Filtering Characteristics of Long Horizontal Line Array 基于长水平线阵模态滤波特性的水声目标深度分类研究

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.11820

Guojun Xu, Weihua Zhang, Min Zhu, Jizhou Guo, Yanqun Wu, Jiahua Zhu

{"title":"Research on Underwater Acoustic Target Depth Classification Based on Modal Filtering Characteristics of Long Horizontal Line Array","authors":"Guojun Xu, Weihua Zhang, Min Zhu, Jizhou Guo, Yanqun Wu, Jiahua Zhu","doi":"10.20855/ijav.2022.27.11820","DOIUrl":"https://doi.org/10.20855/ijav.2022.27.11820","url":null,"abstract":"Considering the problem of depth classification of underwater acoustic targets in shallow water, a classification method based on modal filtering characteristics of long horizontal line array(HLA) beamforming in a negative thermocline environment was proposed. Based on normal mode theory, the spatial filtering characteristics of long HLA are studied by beamforming, and it was found that this characteristic can filter a normal mode. In the negative thermocline environment, the acoustic fields excited by deep and shallow sources and received by deep receivers are controlled by different modes. Surface reflection bottom reflection (SRBR) mode and non-surface reflection bottom reflection (NSRBR) mode show different interference structures in range-spectrum. Based on the characteristics of modal filtering and sound field classification, a depth classification method for shallow water acoustic targets in a negative thermocline environment is established. Numerical results show that the proposed method is robust and can effectively distinguish the acoustic source targets above or below the thermocline (surface and underwater targets) without knowing the specific acoustic environment parameters in advance.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125546212","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

Numerical Simulation and Mechanism Investigations of Cavitating Noise Around a Two-Dimension Valve Pilot Stage 二维阀导级空化噪声数值模拟及机理研究

The International Journal of Acoustics and Vibration Pub Date : 2022-03-29 DOI: 10.20855/ijav.2022.27.11821

Zhao Yonghua, Ruan Jian, Lu Qianqian

{"title":"Numerical Simulation and Mechanism Investigations of Cavitating Noise Around a Two-Dimension Valve Pilot Stage","authors":"Zhao Yonghua, Ruan Jian, Lu Qianqian","doi":"10.20855/ijav.2022.27.11821","DOIUrl":"https://doi.org/10.20855/ijav.2022.27.11821","url":null,"abstract":"The two-dimensional valve integrates the pilot stage and the power stage on one spool, which makes it easy to achieve a fast valve operation and a high frequency response. It has the advantages of simple structure, stable performance and high power to weight ratio. In this paper, the fluid flow in the pilot stage of a 2D valve is analyzed by computational fluid dynamics, and the influence of cavitation on the flow field in the valve is the main study objective. The result shows that the throttling action of the valve port forms a high-speed jet in the chute area of the valve sleeve, and a large area of cavitation cavitation is generated at the same time. The velocity vortex and cavitation work together to intensify the pulsation of the fluid in the valve and become the main source of the noise. In the 2D valve pilot stage, the sound pressure level at the back of the chute of the valve sleeve reaches 175dB, and the maximum sound pressure level at the middle and outlet reaches 168dB. The sound pressure level at the back and middle of the chute decreases first and then increases, and the sound pressure level at the outlet of the chute decreases slowly. In the range of 0 - 5000Hz, the noise energy is concentrated in the low frequency band of less than 1000Hz, showing typical cavitation noise characteristics. The numerical result is favorable with the experimental result.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125616269","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

Influence of Different Modified Gears on the Vibration and Noise of Electric Vehicle Reducer 不同修形齿轮对电动汽车减速器振动和噪声的影响

The International Journal of Acoustics and Vibration Pub Date : 2021-12-22 DOI: 10.20855/ijav.2021.26.41824

Bo Xu, Y. Qiu, Bifeng Yin, X. Hua, H. Du

引用次数: 1

Determination of Notched Input for Equipment Under Random Vibrations 随机振动下设备缺口输入的确定

The International Journal of Acoustics and Vibration Pub Date : 2021-12-22 DOI: 10.20855/ijav.2021.26.41814

K. Renji

{"title":"Determination of Notched Input for Equipment Under Random Vibrations","authors":"K. Renji","doi":"10.20855/ijav.2021.26.41814","DOIUrl":"https://doi.org/10.20855/ijav.2021.26.41814","url":null,"abstract":"Equipment that is mounted on a spacecraft is subjected to random vibration tests to verify whether they can withstand the specified random loads. These tests are generally carried out by using shaker systems during which equipment experiences very high responses at the natural frequencies of the equipment. To reduce such over-testing, notching of the input is done. Notching of the input is normally carried out by considering the force generated at the base and limiting it to a specified value. To accomplish the notching, the force spectrum to be limited and measurement of base force during the tests are needed. This work shows that the acceleration input at the interface of equipment gets reduced at its resonance frequency and this feature can be utilized in arriving at the notched input. An expression to determine the depth of notching is derived and the results are compared with those obtained using numerical simulations. The depth of the notch increases with the response of the oscillator and it is sensitive to the stiffness ratios rather than the mass ratios of the oscillator and the mounting panel. This behavior and the expressions derived can be effectively used in arriving at the notched input for an equipment without the need for measuring the base force, especially for random vibration testing, which is demonstrated with an example.","PeriodicalId":131358,"journal":{"name":"The International Journal of Acoustics and Vibration","volume":"8 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113954541","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

Acoustic Attenuation Performance of Two-Pass Perforated Hybrid Mufflers with Mean Flow 平均流量双通孔混合消声器的消声性能

The International Journal of Acoustics and Vibration Pub Date : 2021-12-22 DOI: 10.20855/ijav.2021.26.41804

Yiliang Fan, Z. Ji

引用次数: 0