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Applied Mathematics and Mechanics(English Edition) 2015年第5期36卷 557-580页

作者： zhijie SHI Yuesheng WAng chuanzeng zh.ng Institute of Engineering Mechanics Beijing Jiaotong University Department of Civil Engineering University of Siegen

A numerical method, the so-called multiple monopole（MMoP） method,based on the generalized multipole technique（GMT） is proposed to calculate the band structures of in-plane waves in two-dimensional phononic crystals, which are composed of arbitrarily shaped cylinders embedded in a solid host medium. To find the eigenvalues（eigenfrequencies） of the problem, besides the sources used to expand the wave fields, an extra monopole source is introduced which acts as the external excitation. By varying the excitation frequency, the eigenvalues can be localized as the extreme points of an appropriately chosen function. By sweeping the frequency range of interest and the boundary of the irreducible first Brillouin zone（FBZ）, the band structures can be obtained. Some typical numerical examples with different acoustic impedance ratios and with inclusions of various shapes are presented to validate the proposed method.

关键词： triangular validate impedance excitation collocation searching elliptical cylinders irreducible scattered

ANALYSIS OF A CRACK IN A FUNCTIONALLY GRADED STRIP WITH A POWER FORM SHEAR MODULUS

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Acta Mechanica Solida Sinica 2009年第5期22卷 465-473页

作者： Jinju Ma zh.ng zh.ng chuanzeng zh.ng School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China Department of Civil Engineering University of Siegen D-57068 Siegen Germany

The plane strain problem of a crack in a functionally graded strip with a power form shear modulus is studied. The governing equation in terms of Airy＇s stress function is solved exactly by means of Fourier transform. The mixed boundary problem is then reduced to a system of singular integral equations and is solved numerically to obtain the stress intensity factor at crack-tip. The maximum circumferential stress criterion and the strain energy density criterion are both employed to predict the direction of crack initiation. Numerical examples are given to show the influence of the material gradation models and the crack sizes on the mode-I and mode-II stress intensity factors. The dependence of the critical kink-angle on the crack size is examined and it is found that the crack kink-angle decreases with the increase of the normalized crack length, indicating that a longer crack tends to follow the original crack-line while it is much easier for a shorter crack to deviate from the original crack-line.

关键词： functionally graded material crack stress intensity factors fracture criterion

High-Temperature and Low-Frequency Acoustic Energy Absorption by a Novel Porous Metamaterial Structure

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Acta Mechanica Solida Sinica 2021年第6期34卷 872-883页

作者： Qihang Liu Xuewei Liu chuanzeng zh.ng Fengxian Xin Department of Civil Engineering University of SiegenSiegen57076Germany State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an710049China

In this paper,we propose a novel porous metamaterial structure with an improved acoustic energy absorption performance at high-temperature and in the low-frequency *** the proposed novel porous metamaterial structure,a porous material matrix containing periodically perforated cylindrical holes arranged in a triangular lattice pattern is applied,and additional interlayers of another porous material are introduced around these *** theoretical model is established by adopting the double porosity theory for the interlayer and the cylindrical hole which form an equivalent inclusion and then applying the homogenization method to the porous metamaterial structure formed by the equivalent inclusion and the porous *** temperature-dependent air and material parameters are considered in the extended theoretical model,which is validated by the finite element results obtained by COMSOL *** acoustic or sound energy absorption performance can be improved remarkably at very low frequencies and high ***,the underlying acoustic energy absorption mechanism inside the unit-cell is investigated by analyzing the distribution of the time-averaged acoustic power dissipation density and the energy dissipation ratio of each constituent porous *** results reveal that regardless of the temperature,the acoustic energy is mostly dissipated in the porous material with a lower airflow resistivity,while the acoustic energy dissipated in the porous material with a higher airflow resistivity also becomes considerable in the high-frequency *** novel porous metamaterial structure proposed in this paper can be efficiently utilized to improve the acoustic energy absorption performance at high temperature.

关键词： Novel porous metamaterial structure Double porosity theory Homogenization method Acoustic or sound energy absorption High temperature

WAVELET METHOD FOR CALCULATIng THE DEFECT STATES OF TWO-DIMENSIONAL PHONONIC CRYSTALS

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Acta Mechanica Solida Sinica 2008年第2期21卷 104-109页

作者： zhizh.ng Yah Yuesheng Wang chuanzeng zh.ng Institute of Engineering Mechanics Beijing Jiaotong University Beijing 100044 China Department of Civil Engineering University of Siegen D-57076 Siegen Germany

Based on the variational theory, a wavelet-based numerical method is developed to calculate the defect states of acoustic waves in two-dimensional phononic crystals with point and line defects. The supercell technique is applied. By expanding the displacement field and the material constants （mass density and elastic stiffness） in periodic wavelets, the explicit formulations of an eigenvalue problem for the plane harmonic bulk waves in such a phononic structure are derived. The point and line defect states in solid-liquid and solid-solid systems are calculated. Comparisons of the present results with those measured experimentally or those from the plane wave expansion method show that the present method can yield accurate results with faster convergence and less computing time.

关键词： acoustic wave phononic crystal defect state wavelet band structure

Aeroelastic analysis and flutter control of wings and panels:A review

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International Journal of Mechanical System Dynamics 2021年第1期1卷 5-34页

作者： Yuyang Chai Wei Gao Benjamin Ankay Fengming Li chuanzeng zh.ng Department of Engineering Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbinChina Department of Civil Engineering University of SiegenSiegenGermany

Flutter is a self‐excited vibration under the interaction of the inertial force,aero-dynamic force,and elastic force of the *** the flutter occurs,the aircraft structures will exhibit limit cycle oscillation,which will cause catastrophic accidents or fatigue damage to the ***,it is of great theoretical and practical significance to study the aeroelastic characteristics and flutter control for improving the aeroelastic stability of aircraft *** paper reviews the recent advances in aeroelastic analysis and flutter control of wings and panel *** me-chanism of aeroelastic flutter of wings and panels is *** research methods of aeroelastic flutter for different structures developed in recent years are briefly *** control strategies including the linear and nonlinear control algorithms as well as the active flutter control results of wings and panels are ***,the paper ends with conclusions,which highlight challenges of the development in aeroelastic analysis and flutter control,and provide a brief outlook on the future *** study aims to present a comprehensive under-standing of aeroelastic analysis and flutter *** can also provide guidance on the design of new wings and panel structures for improving their aeroelastic stability.

关键词： aeroelastic analysis flutter control limit cycle oscillation panel structures wings

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决定二维声子晶体带隙的关键材料参数

功能材料 2009年第3期40卷 413-416页

作者：周晓舟汪越胜 chuanzeng zh.ng 北京交通大学工程力学所北京100044 Department of Civil Engineering University of Siegen Siegen D-57068 Germany

从弹性波动方程入手,获得决定二维声子晶体z模态带隙的关键材料参数是散射体对基体的质量密度比和剪切模量比。利用平面波展开法计算带隙结构,研究正方点阵、三角点阵以及不同填充率时材料参数对带隙的影响。发现质量密度比对带隙起决... 详细信息

从弹性波动方程入手,获得决定二维声子晶体z模态带隙的关键材料参数是散射体对基体的质量密度比和剪切模量比。利用平面波展开法计算带隙结构,研究正方点阵、三角点阵以及不同填充率时材料参数对带隙的影响。发现质量密度比对带隙起决定作用。仅以声阻抗比或波速比的大小不能决定带隙的存在和大小。给出不同点阵形式下产生带隙的材料参数取值范围。给出材料参数-带隙图,对以材料参数设计带隙具有直观的指导作用。

关键词：声子晶体带隙平面波展开法

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周期结构振动带隙特性优化研究进展

哈尔滨工程大学学报 2022年第9期43卷 1229-1240页

作者：熊远皓李凤明张传增哈尔滨工程大学航天与建筑工程学院黑龙江哈尔滨150001 德国锡根大学土木工程系德国锡根D-57068

周期结构(声子晶体或超材料结构)拥有良好的振动带隙特性,从而达到减振降噪的目的。在应用过程中,针对不同减振频率需求,需要对其振动带隙特性进行优化以达到应用需求。本文论述了周期结构振动带隙特性优化的研究进展,介绍了通过对单胞... 详细信息

周期结构(声子晶体或超材料结构)拥有良好的振动带隙特性,从而达到减振降噪的目的。在应用过程中,针对不同减振频率需求,需要对其振动带隙特性进行优化以达到应用需求。本文论述了周期结构振动带隙特性优化的研究进展,介绍了通过对单胞构型、结构尺寸及材料参数等进行优化,以改进此类结构的振动带隙特性,达到不同减振需求的设计及研究方法,展望了振动带隙特性优化的研究前景及思路。周期结构振动带隙特性优化能够有效提升结构的减振特性,有较好的应用前景。

关键词：周期结构振动带隙减振降噪优化

Tunable Fluid-Type Metasurface for Wide-Angle and Multifrequency Water-Air Acoustic Transmission

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Research 2021年第1期2021卷 661-674页

作者： zhandong Huang Shengdong zhao Yiyuan zh.ng zheren Cai zh.ng Li Junfeng Xiao Meng Su Qiuquan Guo chuanzeng zh.ng Yaozong Pan Xiaobing Cai Yanlin Song Jun Yang Department of Mechanical and Materials Engineering The University of Western OntarioLondonOntarioCanada N6A 5B9 School of Mathematics and Statistics Qingdao UniversityQingdao 266071China Institute of Mechanics for Multifunctional Materials and Structures Qingdao UniversityQingdao 266071China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of Sciences(ICCAS)Beijing Engineering Research Center of Nanomaterials for Green Printing TechnologyBeijing National Laboratory for Molecular Sciences(BNLMS)Beijing 100190China Shenzhen Institute for Advanced Study University of Electronic Science and Technology of ChinaShenzhen 518000China Department of Civil Engineering University of SiegenD-57068 SiegenGermany Qingdao Branch of Institute of Acoustics Chinese Academy of SciencesQingdao 266114China

Efficient acoustic communication across the water-air interface remains a great challenge owing to the extreme acoustic impedance *** present acoustic metamaterials can be constructed on the free air-water interface for enhancing the acoustic transmission because of the interface *** strategies overcoming this difficulty were limited in practical usage,as well as the wide-angle and multifrequency acoustic ***,we report a simple and practical way to obtain the wide-angle and multifrequency water-air acoustic transmission with a tunable fluid-type acoustic metasurface(FAM).The FAM has a transmission enhancement of acoustic energy over 200 times,with a thickness less than the wavelength in water by three orders of *** FAM can work at an almost arbitrary water-to-air incident angle,and the operating frequencies can be flexibly *** transmissions can be obtained with multilayer *** experiments,the FAM is demonstrated to be stable enough for practical applications and has the transmission enhancement of over 20 dB for wide *** transmission enhancement of music signal across the water-air interface was performed to demonstrate the applications in acoustic *** FAM will benefit various applications in hydroacoustics and oceanography.

关键词： interface acoustics extreme

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智能压电声子晶体与超材料研究现状与展望

科学通报 2022年第12期67卷 1305-1325页

作者：李政阳王彦正马天雪张传增 Department of Civil Engineering School of Science and Technology University of SiegenD-57076 SiegenGermany

声子晶体与超材料作为一种人工设计的新型材料或结构,具有许多独特和超常的弹性波传播特性,为机械振动的有效控制与弹性波的精准调控提供了一个崭新的研究途径与充满希望的应用机遇.然而,由于传统的声子晶体与超材料在加工制备之后不易... 详细信息

声子晶体与超材料作为一种人工设计的新型材料或结构,具有许多独特和超常的弹性波传播特性,为机械振动的有效控制与弹性波的精准调控提供了一个崭新的研究途径与充满希望的应用机遇.然而,由于传统的声子晶体与超材料在加工制备之后不易根据实际需求重新调整其几何参数和材料属性,大大限制了其实际应用.基于压电或力-电耦合效应的智能压电声子晶体与超材料,通过调节电场即可按需调控结构的振动或波动特性,可大大拓宽传统声子晶体与超材料的应用范围.本文依据压电材料与弹性材料或结构不同的融合形式,试图将智能压电声子晶体与超材料大致分为三类:第一类为单一压电声子晶体与超材料,此类仅由单一的压电材料组成,可以外接电极也可以无外接电极;第二类为内嵌式压电/弹性复合材料型压电声子晶体与超材料,该类由压电散射体埋嵌在弹性基体中而构成,当然也可将压电材料与弹性基体的角色互换;第三类为由外贴式压电片与弹性结构组成的复合型压电声子晶体与超材料,此类将压电片外贴在弹性基体结构(杆、梁、板等)的表面.已有研究表明,相较于其他弹性波调控方式,基于压电或力-电耦合效应的智能压电声子晶体和超材料的主要优势体现在反应迅速,无须改变原有结构的固有形状与组成.仅依靠压电效应而无外接电路或主动控制的情况下,压电效应对机械振动和弹性波调控幅度十分有限,效率较低,但通过外接电路或主动控制可拓宽布拉格带隙,激发新的局域共振带隙,融合布拉格和局域共振带隙,并能有效达到上述新颖弹性波特性调控的目的.最后,在总结已有研究成果的基础上,对该领域的研究现状给出了若干结论,同时指出了仍然存在的一些问题,并对未来研究的需求、期待与发展趋势进行了展望.

关键词：智能声子晶体智能超材料压电材料外接电路主动控制振动与弹性波传播

Transmission of two-dimensional liquid-liquid Phononic Crystals

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Transmission of two-dimensional liquid-liquid Phononic Cryst...