Zhenxing Li, K. Wu, Yi Wen, Jiamin Yao, Meiying Guo, Lijun Wang
The ballistic free-fall absolute gravimeters are widely used in acquiring information of gravity field and the self-vibration of the absolute gravimeter is crucial for high precision gravitational measurement. The self-vibration of the T-1 absolute gravimeter has a multi-directional full-band excitation. The resulted horizontal swing has the major impact, since the T-1 absolute gravimeter is simplified as a cantilever beam. A laser vibrometer was applied to directly measure the mechanical self-vibration. The frequency of self-vibration has a nonlinear effect on the measurement error of g, and the peak frequencies should be avoided. The vibration signal was analyzed in time and frequency domain by continuous wavelet transform (CWT). The close frequency profiles were measured in the scalogram and the beat vibrations were observed in time domain as the results of the horizontal swing. The 38 Hz self-vibration had the dominating effect on the measurement error of g for T-1 absolute gravimeter. After optimizing the structure of the tripod, the dominating frequency increased from 38 Hz to 42 Hz. A 11% increase of the vibration frequency can reduce the measurement error of g.
{"title":"Self-Vibration Analysis of the Free-Fall Absolute Gravimeter","authors":"Zhenxing Li, K. Wu, Yi Wen, Jiamin Yao, Meiying Guo, Lijun Wang","doi":"10.1115/imece2019-10836","DOIUrl":"https://doi.org/10.1115/imece2019-10836","url":null,"abstract":"\u0000 The ballistic free-fall absolute gravimeters are widely used in acquiring information of gravity field and the self-vibration of the absolute gravimeter is crucial for high precision gravitational measurement. The self-vibration of the T-1 absolute gravimeter has a multi-directional full-band excitation. The resulted horizontal swing has the major impact, since the T-1 absolute gravimeter is simplified as a cantilever beam. A laser vibrometer was applied to directly measure the mechanical self-vibration. The frequency of self-vibration has a nonlinear effect on the measurement error of g, and the peak frequencies should be avoided. The vibration signal was analyzed in time and frequency domain by continuous wavelet transform (CWT). The close frequency profiles were measured in the scalogram and the beat vibrations were observed in time domain as the results of the horizontal swing. The 38 Hz self-vibration had the dominating effect on the measurement error of g for T-1 absolute gravimeter. After optimizing the structure of the tripod, the dominating frequency increased from 38 Hz to 42 Hz. A 11% increase of the vibration frequency can reduce the measurement error of g.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129943824","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}
This paper presents a novel shape memory metamaterial, which can achieve adaptively tunable bandgaps for ultra-wide frequency spectrum vibration control. The microstructure is composed of a Shape Memory Alloy (SMA) wire and a metallic spring combined together with bakelite blocks, loaded by a lumped mass made of lead. The adaptive bandgap mechanism is achieved via the large deformation of the metamaterial unit cell structure during the heating and cooling cycle. By applying different heating temperature on the SMA wire, morphing microstructural shapes can be achieved. Parametric design is conducted by adjusting the lead block mass. Finally, an optimized microstructural design rendering a large deformation is chosen. Finite element models (FEMs) are constructed to analyze the dynamic behavior of the metamaterial system. Effective mass density of the unit cell is calculated to investigate and demonstrate the bandgap tuning phenomenon. In the simulation, two extreme shapes are simulated adhering to the experimental observations. The effective negative mass density and the moving trends are obtained, representing the development and shifting of the bandgaps. The width of the bandgap region covers about 50 Hz from the room-temperature state to the heating state. This enables the vibration suppression within this wide frequency region. Subsequently, a metamaterial chain containing ten unit cells is modeled, aligned on an aluminum cantilever beam. An external normal force with a sweeping frequency is applied on the beam near the fixed end. Harmonic analysis is performed to further explore the frequency response of the mechanical system. The modeling results from modal analysis, effective mass density extraction, and harmonic analysis agree well with each other, demonstrating the prowess of the proposed shape memory metamaterial for ultra-wide frequency spectrum control.
{"title":"Shape Memory Metamaterials With Adaptive Bandgaps for Ultra-Wide Frequency Spectrum Vibration Control","authors":"Yihao Song, Yanfeng Shen","doi":"10.1115/imece2019-10902","DOIUrl":"https://doi.org/10.1115/imece2019-10902","url":null,"abstract":"\u0000 This paper presents a novel shape memory metamaterial, which can achieve adaptively tunable bandgaps for ultra-wide frequency spectrum vibration control. The microstructure is composed of a Shape Memory Alloy (SMA) wire and a metallic spring combined together with bakelite blocks, loaded by a lumped mass made of lead. The adaptive bandgap mechanism is achieved via the large deformation of the metamaterial unit cell structure during the heating and cooling cycle. By applying different heating temperature on the SMA wire, morphing microstructural shapes can be achieved. Parametric design is conducted by adjusting the lead block mass. Finally, an optimized microstructural design rendering a large deformation is chosen. Finite element models (FEMs) are constructed to analyze the dynamic behavior of the metamaterial system. Effective mass density of the unit cell is calculated to investigate and demonstrate the bandgap tuning phenomenon. In the simulation, two extreme shapes are simulated adhering to the experimental observations. The effective negative mass density and the moving trends are obtained, representing the development and shifting of the bandgaps. The width of the bandgap region covers about 50 Hz from the room-temperature state to the heating state. This enables the vibration suppression within this wide frequency region. Subsequently, a metamaterial chain containing ten unit cells is modeled, aligned on an aluminum cantilever beam. An external normal force with a sweeping frequency is applied on the beam near the fixed end. Harmonic analysis is performed to further explore the frequency response of the mechanical system. The modeling results from modal analysis, effective mass density extraction, and harmonic analysis agree well with each other, demonstrating the prowess of the proposed shape memory metamaterial for ultra-wide frequency spectrum control.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131636206","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}
Locally resonant metamaterials are capable of demonstrating low-frequency vibration absorption due to the formation of stop-bands. In this work, the multi-mode vibration absorption capability of an adaptive nonlinear metamaterial beam is investigated. The metamaterial beam is idealized as a hinged-hinged finite Euler-Bernoulli beam with a von-Kármán geometric type nonlinearity that is attached to a distributed cellular array of shape memory alloy (SMA) spring–mass resonators. Numerical studies are performed to evaluate the effects of dissipation and change in elastic modulus due to material phase change of SMA pseudoelasticity on the dynamic response of the beam. Using a modal analysis approach, stop-bands are generated at the first three nonlinear frequencies of the beam. The frequency response demonstrates a hardening behavior at a temperature significantly higher than the austenite finish temperature while conversely demonstrating a softening behavior at a temperature slightly above the austenite finish temperature.
{"title":"Vibration Absorption in a Nonlinear Metamaterial Beam Incorporating Shape Memory Alloys","authors":"R. Fernandes, J. Boyd, S. El-Borgi, D. Lagoudas","doi":"10.1115/imece2019-11302","DOIUrl":"https://doi.org/10.1115/imece2019-11302","url":null,"abstract":"\u0000 Locally resonant metamaterials are capable of demonstrating low-frequency vibration absorption due to the formation of stop-bands. In this work, the multi-mode vibration absorption capability of an adaptive nonlinear metamaterial beam is investigated. The metamaterial beam is idealized as a hinged-hinged finite Euler-Bernoulli beam with a von-Kármán geometric type nonlinearity that is attached to a distributed cellular array of shape memory alloy (SMA) spring–mass resonators. Numerical studies are performed to evaluate the effects of dissipation and change in elastic modulus due to material phase change of SMA pseudoelasticity on the dynamic response of the beam. Using a modal analysis approach, stop-bands are generated at the first three nonlinear frequencies of the beam. The frequency response demonstrates a hardening behavior at a temperature significantly higher than the austenite finish temperature while conversely demonstrating a softening behavior at a temperature slightly above the austenite finish temperature.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116292792","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}
C. Linhares, João S. Costa, R. Teixeira, C. Coutinho, S. Tavares, J. E. Santo, H. Mendes
Power transformers are associated with the radiation of unwanted noise in many circumstances due to its low frequency and relative high power, which reduction and mitigation is imperative. It is known that the main source of this noise are originated by the vibrations induced in the active part, namely the core, primarily due to electromagnetic forces and magnetomechanical effects. On the other hand, the laminated design of the core is indispensable in order to reduce the Foucault currents losses. Thus, in addition to the electrical requirements, the development of an appropriate model of the core dynamic behavior taking into account its segmented structure is urgent, in order to avoid resonances at any of the excitation frequencies. In the current proceeding, the influence of the core equivalent dynamic mechanical properties on a power transformer radiated noise was studied by performing a numerical parametric analysis. It was concluded that the active part stiffness properties, namely the directional component related to the out of lamination plane bending, ruled the vibroacoustic behavior of the transformer for the studied frequency range.
{"title":"Influence of Active Part Stiffness on Radiated Sound Power Level in Power Transformers","authors":"C. Linhares, João S. Costa, R. Teixeira, C. Coutinho, S. Tavares, J. E. Santo, H. Mendes","doi":"10.1115/imece2019-11513","DOIUrl":"https://doi.org/10.1115/imece2019-11513","url":null,"abstract":"\u0000 Power transformers are associated with the radiation of unwanted noise in many circumstances due to its low frequency and relative high power, which reduction and mitigation is imperative. It is known that the main source of this noise are originated by the vibrations induced in the active part, namely the core, primarily due to electromagnetic forces and magnetomechanical effects. On the other hand, the laminated design of the core is indispensable in order to reduce the Foucault currents losses. Thus, in addition to the electrical requirements, the development of an appropriate model of the core dynamic behavior taking into account its segmented structure is urgent, in order to avoid resonances at any of the excitation frequencies. In the current proceeding, the influence of the core equivalent dynamic mechanical properties on a power transformer radiated noise was studied by performing a numerical parametric analysis. It was concluded that the active part stiffness properties, namely the directional component related to the out of lamination plane bending, ruled the vibroacoustic behavior of the transformer for the studied frequency range.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128914949","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}
Investigating the acoustic radiation of stiffened plate structures is significant to the advancement of aircraft, automobile, and marine vehicle design. Plate and stiffener design variables affect how the global structure vibrates and radiates sound. The objective of this paper is to provide insight into how sensitive a periodically stiffened plate radiates sound in air with respect to its design variables. This paper examines a clamped plate that is periodically stiffened along one direction. Finite element analysis is used to quantify the structural acoustic behavior of the plate subject to a harmonic point load at the plate’s center. Fourier transforms are performed along the plate’s surface to reveal the wavenumber content of the plate. Lastly, radiated sound power from the plate surface is computed. A baseline plate without stiffeners is used for finite element modeling validation. Next, periodically spaced beams used for plate stiffening are inserted and varied in thickness. In addition, the plate thickness is also varied. Varying the plate thickness and the stiffener thickness provides insight to each design variable’s contribution to vibration and radiated sound power. The quantified findings from these parametric case studies serve as an insight into the structural acoustic performance of periodically stiffened structures.
{"title":"Analysis of Structural Acoustic Design Variables for a Periodically Stiffened Plate Using the Finite Element Method","authors":"Joseph A. Blochberger","doi":"10.1115/imece2019-10259","DOIUrl":"https://doi.org/10.1115/imece2019-10259","url":null,"abstract":"\u0000 Investigating the acoustic radiation of stiffened plate structures is significant to the advancement of aircraft, automobile, and marine vehicle design. Plate and stiffener design variables affect how the global structure vibrates and radiates sound. The objective of this paper is to provide insight into how sensitive a periodically stiffened plate radiates sound in air with respect to its design variables.\u0000 This paper examines a clamped plate that is periodically stiffened along one direction. Finite element analysis is used to quantify the structural acoustic behavior of the plate subject to a harmonic point load at the plate’s center. Fourier transforms are performed along the plate’s surface to reveal the wavenumber content of the plate. Lastly, radiated sound power from the plate surface is computed.\u0000 A baseline plate without stiffeners is used for finite element modeling validation. Next, periodically spaced beams used for plate stiffening are inserted and varied in thickness. In addition, the plate thickness is also varied. Varying the plate thickness and the stiffener thickness provides insight to each design variable’s contribution to vibration and radiated sound power. The quantified findings from these parametric case studies serve as an insight into the structural acoustic performance of periodically stiffened structures.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132452903","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}
Lamb wave is considered as an appropriate approach to detect the cracks in structures. This paper combines an efficient time-domain spectral finite element with time reversal method to develop an efficient breathing crack detection method. In this regard, Gauss-Lobatto-Legendre quadrature rules and penalty function method are carried out to construct an effective and accurate approach. Comparing the computation scales and results of this method and traditional finite element method, the validity and superiority of the proposed model is stressed. The reconstructed signals of two scenarios, intact and impaired structures, are captured. It is concluded that, this approach is capable of detecting breathing cracks. In addition, the influences of the relative depth of the notch and incident region are studied. This research may provide the guidance for experiment configuration and the further study.
{"title":"Time-Domain Spectral Element Simulation of Lamb Wave Time Reversal Method for Detecting a Breathing Crack in a Plate","authors":"Zexing Yu, Fei Du, Chao Xu","doi":"10.1115/imece2019-10495","DOIUrl":"https://doi.org/10.1115/imece2019-10495","url":null,"abstract":"\u0000 Lamb wave is considered as an appropriate approach to detect the cracks in structures. This paper combines an efficient time-domain spectral finite element with time reversal method to develop an efficient breathing crack detection method. In this regard, Gauss-Lobatto-Legendre quadrature rules and penalty function method are carried out to construct an effective and accurate approach. Comparing the computation scales and results of this method and traditional finite element method, the validity and superiority of the proposed model is stressed. The reconstructed signals of two scenarios, intact and impaired structures, are captured. It is concluded that, this approach is capable of detecting breathing cracks. In addition, the influences of the relative depth of the notch and incident region are studied. This research may provide the guidance for experiment configuration and the further study.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127982909","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}
In this study, a broadband frequency tunable dynamic absorber was designed and fabricated based on the primary design principle of a mass damper. A magneto-rheological elastomer that can change the relative stiffness when an external magnetic field is applied was used to control the natural frequency of the movable mass of the absorber. A coil to generate the magnetic field was also used as a movable mass to decrease the total weight and to create a constant closed loop of the magnetic force. The hammer impact test results show that the present absorber could change its natural frequency with minimal electric power and had a constant damping ratio. Experimental results of vibration absorbing of an acrylic flat plate show that the proposed absorber could change the natural frequency of the movable mass and reduce the vibration over a wide band by constantly applying the optimum current to the coil in the device with a small power consumption (less than 10 W). Therefore, the proposed absorber works effectively. Further, a technique to determine the electric current applied to the coil automatically based on the phase difference of the vibrational acceleration of the movable mass and the vibrating objective was also presented.
{"title":"Development and Design of the Dynamic Vibration Absorber Using Magneto-Rheological Elastomer for the Weight and Power Consumption Saving","authors":"O. Terashima, M. Nakata, T. Komatsuzaki","doi":"10.1115/imece2019-10776","DOIUrl":"https://doi.org/10.1115/imece2019-10776","url":null,"abstract":"\u0000 In this study, a broadband frequency tunable dynamic absorber was designed and fabricated based on the primary design principle of a mass damper. A magneto-rheological elastomer that can change the relative stiffness when an external magnetic field is applied was used to control the natural frequency of the movable mass of the absorber. A coil to generate the magnetic field was also used as a movable mass to decrease the total weight and to create a constant closed loop of the magnetic force. The hammer impact test results show that the present absorber could change its natural frequency with minimal electric power and had a constant damping ratio. Experimental results of vibration absorbing of an acrylic flat plate show that the proposed absorber could change the natural frequency of the movable mass and reduce the vibration over a wide band by constantly applying the optimum current to the coil in the device with a small power consumption (less than 10 W). Therefore, the proposed absorber works effectively. Further, a technique to determine the electric current applied to the coil automatically based on the phase difference of the vibrational acceleration of the movable mass and the vibrating objective was also presented.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122659662","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}
Chang Liu, Xu Mao, Juan Heredia Juesas, A. Molaei, J. Martinez-Lorenzo
Seismic and electromagnetic imaging modalities are conventionally used in subsurface situational awareness applications. These modalities have been very effective at characterizing the geological media in terms of its constitutive mechanical properties such as density and compressibility, as well as electromagnetic properties such as electric conductivity, permeability, and permittivity. In order to enhance these imaging capabilities, a Thermoacoustic (TA) imaging system is used in this work. TA imaging relies on the coupling of mechanical and electromagnetic waves through a thermodynamic process, and it has the potential to reconstruct thermodynamic constitutive properties such as volumetric expansion coefficient and heat capacity. TA imaging has been mostly used in biological applications; this is due to the low signal-to-noise ratio that can be created with this physical mechanism. This work is aimed at addressing such limitation and exploring the use of TA imaging in geophysical applications. Conventionally, a short microwave pulse excitation is used to create the TA wave; so that the stress confinement condition is met while providing high resolution images. This approach requires the use of expensive high power amplifiers to create a detectable TA signal. This limitation can be addressed by using a frequency-modulated continuous wave (FMCW) excitation, which has been recently proposed as a suitable mechanism to enhance the signal-to-noise ratio of the TA signal generated for a given peak power constrain. This paper discusses and compares both pulsed and FMCW TA imaging in geological media. Preliminary experimental results show the efficacy of this approach to image a rock immersed in an oil bath; thus paving the way towards its future use for subsurface sensing and imaging of fluid flow and transport in porous media.
{"title":"Preliminary Results of Microwave Induced Thermoacoustics Imaging in Geological Media","authors":"Chang Liu, Xu Mao, Juan Heredia Juesas, A. Molaei, J. Martinez-Lorenzo","doi":"10.1115/imece2019-11943","DOIUrl":"https://doi.org/10.1115/imece2019-11943","url":null,"abstract":"\u0000 Seismic and electromagnetic imaging modalities are conventionally used in subsurface situational awareness applications. These modalities have been very effective at characterizing the geological media in terms of its constitutive mechanical properties such as density and compressibility, as well as electromagnetic properties such as electric conductivity, permeability, and permittivity. In order to enhance these imaging capabilities, a Thermoacoustic (TA) imaging system is used in this work. TA imaging relies on the coupling of mechanical and electromagnetic waves through a thermodynamic process, and it has the potential to reconstruct thermodynamic constitutive properties such as volumetric expansion coefficient and heat capacity. TA imaging has been mostly used in biological applications; this is due to the low signal-to-noise ratio that can be created with this physical mechanism. This work is aimed at addressing such limitation and exploring the use of TA imaging in geophysical applications. Conventionally, a short microwave pulse excitation is used to create the TA wave; so that the stress confinement condition is met while providing high resolution images. This approach requires the use of expensive high power amplifiers to create a detectable TA signal. This limitation can be addressed by using a frequency-modulated continuous wave (FMCW) excitation, which has been recently proposed as a suitable mechanism to enhance the signal-to-noise ratio of the TA signal generated for a given peak power constrain. This paper discusses and compares both pulsed and FMCW TA imaging in geological media. Preliminary experimental results show the efficacy of this approach to image a rock immersed in an oil bath; thus paving the way towards its future use for subsurface sensing and imaging of fluid flow and transport in porous media.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125528616","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}
In recent times, due to the increase in global energy commodities prices, aero-engine manufacturers are investing in advanced aero-engine technologies to reduce the operating costs. These innovative technologies include overall weight reductions to develop efficient aero-engines. Due to these circumstances, the overall exposure of the aero-engine to vibration transfer due to various loading conditions such as the rotor loading forces has significantly increased. Due to advancement in technologies and demand for greater passenger comfort, vibration transfer reduction to the aircraft fuselage has received prominent attention. In this paper, an analytical transmissibility study called the bond graph Transfer Path Analysis (TPA) has been extensively studied and its applications are explored. Bond Graph TPA is a reliable and feasible theoretical methodology that can be implemented on various large mechanical systems in the design stages to tackle noise and vibration problems before prototyping to significantly reduce the development costs. Bond graph transfer path analysis (TPA) is an advantageous method compared to the existing empirical TPA methodologies such as the Operational Path Analysis due to its efficient analytical nature. In this paper, bond graph TPA has been implemented on a reduced aero-engine model to determine vibration contribution at various aero-engine locations to propose structural design guidelines to minimize the vibration transfer.
近年来，由于全球能源商品价格的上涨，航空发动机制造商正在投资于先进的航空发动机技术，以降低运营成本。这些创新技术包括整体重量减轻，以开发高效的航空发动机。由于这些情况，由于各种载荷条件，如转子载荷力，航空发动机的整体暴露于振动传递显著增加。由于技术的进步和对乘客舒适度的要求，减少飞机机身的振动传递受到了人们的广泛关注。本文对键图传递路径分析(TPA)进行了广泛的研究，并对其应用进行了探讨。Bond Graph TPA是一种可靠可行的理论方法，可在设计阶段应用于各种大型机械系统，在原型设计前解决噪声和振动问题，显著降低开发成本。键合图传递路径分析(Bond graph transfer path analysis, TPA)由于其高效的分析特性，与现有的经验TPA方法(如操作路径分析)相比，具有优势。本文在一个简化的航空发动机模型上实现键合图TPA，以确定航空发动机不同位置的振动贡献，从而提出最小化振动传递的结构设计准则。
{"title":"Aero-Engine Vibration Propagation Analysis Using Bond Graph Transfer Path Analysis and Transmissibility Theory","authors":"Seyed-Ehsan Mir-Haidari, K. Behdinan","doi":"10.1115/imece2019-10773","DOIUrl":"https://doi.org/10.1115/imece2019-10773","url":null,"abstract":"\u0000 In recent times, due to the increase in global energy commodities prices, aero-engine manufacturers are investing in advanced aero-engine technologies to reduce the operating costs. These innovative technologies include overall weight reductions to develop efficient aero-engines. Due to these circumstances, the overall exposure of the aero-engine to vibration transfer due to various loading conditions such as the rotor loading forces has significantly increased. Due to advancement in technologies and demand for greater passenger comfort, vibration transfer reduction to the aircraft fuselage has received prominent attention. In this paper, an analytical transmissibility study called the bond graph Transfer Path Analysis (TPA) has been extensively studied and its applications are explored. Bond Graph TPA is a reliable and feasible theoretical methodology that can be implemented on various large mechanical systems in the design stages to tackle noise and vibration problems before prototyping to significantly reduce the development costs. Bond graph transfer path analysis (TPA) is an advantageous method compared to the existing empirical TPA methodologies such as the Operational Path Analysis due to its efficient analytical nature. In this paper, bond graph TPA has been implemented on a reduced aero-engine model to determine vibration contribution at various aero-engine locations to propose structural design guidelines to minimize the vibration transfer.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127683786","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}
The paper presents an investigation into the noise generated by structural vibration of an electric motor used in appliance products using Computational Simulation Approach. In particular, a 3-D numerical simulation model is specifically developed to predict the frequency response of the stator under three different simulation conditions: radial force only, tangential force only and the combination of both forces. The obtained data is used to analyze the acoustic generation in the far-field. Experimental is used to validate the predicted results. It shows the predicted results are very close to experimental results.
{"title":"An Investigation Into Structural-Induced Noise in an Electric Motor","authors":"T. Vuong, W. Li, A. Al-Jumaily, Neel Pandey","doi":"10.1115/imece2019-10197","DOIUrl":"https://doi.org/10.1115/imece2019-10197","url":null,"abstract":"\u0000 The paper presents an investigation into the noise generated by structural vibration of an electric motor used in appliance products using Computational Simulation Approach. In particular, a 3-D numerical simulation model is specifically developed to predict the frequency response of the stator under three different simulation conditions: radial force only, tangential force only and the combination of both forces. The obtained data is used to analyze the acoustic generation in the far-field. Experimental is used to validate the predicted results. It shows the predicted results are very close to experimental results.","PeriodicalId":197121,"journal":{"name":"Volume 11: Acoustics, Vibration, and Phononics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134423334","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}
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