3月19-20日bbin电子-俄罗斯科学院 “声学与振动创新技术”2018国际研讨会

    The 2018 International Symposium of the ZJUT - RAS International Laboratory of “Sound and Vibration Research and Innovation”
    bbin电子-俄罗斯科学院 “声学与振动创新技术”2018国际研讨会
    
    承办：
    One Belt One Road, Zhejiang, China-Russia, ZJUT-RAS Joint Research Laboratory of Innovative Technology on Acoustics and Vibration
    浙江省“一带一路”bbin电子-俄罗斯科学院“声学与振动创新技术”国际联合实验室
    
    讲座安排：
    讲座地点：bbin电子朝晖校区北门重点实验室A220

  
    讲座主题：Improved Series Expansions for the Solution of Beams Carrying Moving Dynamic Subsystems
    报告人：Prof. Lawrence A. Bergman
    报告人简介：
    Zhejiang 1000 Global Expert, Dept. of Aerospace Engineering, University of Illinois at Urbana-Champaign; Sound and Vibration Laboratory, College of Mechanical Engineering, Zhejiang University of Technology; One Belt One Road, Zhejiang, China-Russia, ZJUT-RAS Joint Research Laboratory of Innovative Technology on Acoustics and Vibration
    主题简介：
    The dynamic analysis of beams under the action of moving point loads has certain complications.  First, if the point loads are caused by subsystems that exhibit dynamics of their own, the interactions between those subsystems and the beam are not known explicitly beforehand but, rather, must be determined as part of the analysis.  Second, while the time dependent distributions of displacement and slope of the beam can be accurately determined through series solution, the prediction of bending moment and shear force distributions are compromised by the moving singularity in the shear force at the point of loading, which requires many terms in the approximating series to achieve reasonable accuracy.  In this talk I’ll discuss an alternate formulation that we’ve developed for this class of problems that accelerates convergence of both bending moment and shear force distributions.
    
    讲座主题：Design of a Nonlinear Energy Sink for a Wing in Transonic Flow
    报告人：Prof. D. Michael McFarland
    报告人简介：
    Zhejiang 1000 Global Expert, Dept. of Aerospace Engineering, University of Illinois at Urbana-Champaign; Sound and Vibration Laboratory, College of Mechanical Engineering, Zhejiang University of Technology; One Belt One Road, Zhejiang, China-Russia, ZJUT-RAS Joint Research Laboratory of Innovative Technology on Acoustics and Vibration
    主题简介：
    Under certain flight conditions, aircraft structures such as wings and fins can become unstable and “flutter”. Although linear analysis usually predicts unbounded growth of these vibrations, in practice their amplitude is often limited by structural or aerodynamic nonlinearities. The resulting limit cycle oscillation (LCO), while not necessarily leading to catastrophic failure, can adversely affect aircraft and pilot performance or require restrictions on loading or maneuvers.
    We have proposed the use of targeted energy transfer (TET) to inhibit the development of LCO by transferring energy from the aircraft surface to a spatially local attachment, a nonlinear energy sink (NES), exploiting the transient nature of LCO onset and thus avoiding the need to fight the steady-state vibration. The performance of the NES in this application has been extensively analyzed, and even demonstrated experimentally at low speed. This talk will review some of these results, then focus on the development of an NES for use with an existing wing at transonic speeds. The finite element analysis of the wing, validation and model updating through ground vibration tests of a wind tunnel model, incorporation of modal data from the FEA into a computational aeroelastic code, and the modification of that code to accommodate the structural nonlinearities that accompany the connection of the NES will be discussed. Results predicting the aeroelastic response of the wing-NES system will be presented.
  
    讲座主题：Methods of Study of Vibroacoustic Characteristics of Complex Mechanoacoustical Systems
    报告人：Dr. Konstantin Kostylev
    报告人简介：
    Head of sector, Institute of Applied Physics, Russian Academy of Sciences, IAP RAS
    主题简介：
    First, some information is presented about the Institute of Applied Physics and for the Center for hydroacoustics, which is the Institutes division. Then we will discuss diagnostics of mechanoacoustic systems by means of methods of time reversal and wave front reversal. This methods allows focusing vibration field in an elastic system of finite size. Experimental implementation of a method for searching for vibroactivity and sources and maintenance defects in complex structures will be reported. This includes a search algorithm for a tonal source, an experiment with a wideband source, and the defect search. Then we will discuss a method to determine the contribution of an individual source to the vibrational and acoustic field of a structure in presence of other noise and vibration. Finaly,  proposals for joint research are made in the concluding part.

    讲座主题：Numerical Methods for Studying the Acoustic Characteristics of Complex Elastic Systems: Possibilities and Prospects
    报告人：Dr. M. B. Salin
    报告人简介：
    Head of Vibroacoustic Laboratory, Institute of Applied Physics, Russian Academy of Sciences, IAP RAS ; One Belt One Road, Zhejiang, China-Russia, ZJUT-RAS Joint Research Laboratory of Innovative Technology on Acoustics and Vibration
    主题简介：
    In order to simulate oscillation of an elastic body in fluid and large scale field problems, an advanced software, ASTRA, is developed with finite element method and acoustical Super element technology.  It solves computing levels of noise radiated by a vibrating shell, obtains modal analysis of underwater structures when attenuation is included, and applies the procedure of automatic adjustment of the finite element model. In this seminar, hydrodynamic noise simulation will be introduced as well as the scattering noise problems. Experimental validation of ASTRA’s simulations is exerted on the submarine expedition. Doppler frequency shift of the scattered signal is considered in the calculation. Computation of the scattered field and tracking the object is validated in the experiments and simulations.
 
    讲座主题：Nearfield Acoustic Holography Research Progresses in ZJUT
    报告人：Prof.  Huancai Lu
    报告人简介：
    Zhejiang 1000 Global Expert, Sound and Vibration Laboratory, School of Mechanical Engineering, Zhejiang University of Technology; One Belt One Road, Zhejiang, China-Russia, ZJUT-RAS Joint Research Laboratory of Innovative Technology on Acoustics and Vibration
    主题简介：
    The introduction to Sound and Vibration Laboratory (SVLab) and Zhejiang University of Technology (ZJUT) will be presented, including ongoing research and projects. Some works done in the SVLab on Nearfield Acoustic Holography, Wave Separation will also be presented. The following topics will be particularly addressed:
    1. Therotical foundamentals of Nearfield Acoustical Holography,
    2. Spherical microphone array and Spherical Nearfield Acoustical Holography,
    3. Sound wave separation and sound field reconstruction with single layer microphone array,
    4. Reconstruction of sound quailty objective paramenters in 3D space.

    讲座主题：Experimental Investigations of Center for Hydroacoustics of  IAP RAS
    报告人：A.V. Stulenkov
    报告人简介：
     PhD Student of IAP RAS
    主题简介：
    The report is devoted to the main directions of experimental investigations provided by the Center for Hydroacoustics of the Institute of Applied Physics of the Russian Academy of Sciences. The report describes the main methods of exploration and analysis of dynamic characteristics (natural frequencies, transmission coefficients, vibration modes) of complex structures, methods for finding sources of increased noise and vibration, and ways of determination the paths of transferring energy from a source to a control point. The report pays attention to the measurement equipment and measuring systems, which are developed in the institute and tested in practice and which allow to solve a wide range of problems assigned to the researchers.

    讲座主题：Sound Field Description in the Underwater Acoustic Waveguide
    报告人：Yu. M. Makarova
    报告人简介：
    Master Student of Lobachevski State University of Nizhny Novgorod, UNN
    主题简介：
    The presentation considers three traditional approaches for the evaluation of sound fields in the underwater acoustic waveguides: the method of wide angle parabolic equation, the method of normal modes, and the method of geometrical optics. In addition, the stable components of sound field are introduced. These components are less sensitive to the sound speed perturbation than the total field. These components can be extracted from the field recorded by a long vertical antenna using the coherent state expansion borrowed from quantum mechanics.

    讲座主题：Some Tasks in the Processing of Acoustic Signals
    报告人：D.A. Kosteev
    报告人简介：
    Master Student of Lobachevski State University of Nizhny Novgorod, UNN
    主题简介：
    First part of the presentation is devoted to the signal processing for the underwater acoustic experiment. Broadband signals were transmitted and received by a horizontal linear array. Frequency of the source and angle of the source location were estimated. In addition to that, parameters of the reverberation signal, which followed the transmitted signal, were investigated. This research was included into Bachelor’s thesis.
    Second part of the presentation is devoted to the usage of nearfield acoustic holography methods (NAH) for predicting far field of the object. An experiment was carried out in anechoic chamber. First, acoustic filed was recorded in a plane that was close to source. Using this we can reconstruct the far field. Second, we measured the signal in the far field and compared the results. The research will be included in the Master’s thesis.
    Finally, an experimental setup is proposed, that can by build and exploited in ZHUT. The experimental setup allow to do research both on NAH and acoustic positioning.