颗粒阻尼技术及柔性带状颗粒阻尼器

介绍了一种新型的柔性带状颗粒阻尼器及其减振机制,为工程设计中的减少振动和降低噪声提供了有效途径。根据在振动控制领域利用外加耗能装置以耗散结构振动能量的设想,讨论了柔性带状颗粒阻尼器的构成并通过桁架模型的减振试验,验证了柔性带状颗粒阻尼器的减振效果。得出颗粒阻尼技术及柔性带状颗粒阻尼器是一种具有较大研究和开发空间的新产品,对杆状、管状、构件减振具有重要的指导意义。     

新型集成式双气室油气阻尼器的联通工作模式动力学特性分析

针对传统基于集成式油气阻尼器联通工作模式的优缺点,提出一种新型的基于集成式双气室油气阻尼器的联通式工作模式。该新型集成式双气室油气阻尼器是通过在传统集成式单气室阻尼器的环状油腔中增设辅助气腔来得以实现。针对该新型集成式双气室油气阻尼器的联通式工作模式,建立本构模型,并在充分分析其工作原理的基础上,结合实验数据通过AMESim软件建立其仿真模型,并针对仿真模型开展其动力学分析,与两类已提出的基于集成式单气室油气阻尼器的联通工作模式进行比较。结果表明：该结构能够改善传统油气阻尼器联通工作模式在同步、异步工作中出现的负压力以及输出力畸变的问题,并能提供较好的刚度特性。在此基础上,讨论了该新型集成式油气阻尼器的联通式工作模式的结构参数对系统工作性能的影响,为该结构进一步在协同减振以及车辆悬架系统的应用提供参考。     

基于CuZnAl形状记忆合金的框架结构抗震减振控制

利用形状记忆合金的本构关系,分析了在自由应力状态下的残余应变与温度的关系.使用动态数据采集分析仪,测试了安装CuZnAl形状记忆合金耗能器的框架结构的减振性能;应用电子万能拉伸试验机测试了CuZnAl形状记忆合金的应力-应变滞回曲线,借助透射电子显微镜,分析了CuZnAl形状记忆合金在热机械循环过程中显微组织的变化;比较了不同热处理工艺对CuZnAl形状记忆合金热机械循环后的滞回曲线面积及减振性能的影响.结果表明:CuZnAl形状记忆合金用于框架结构具有较好的减振效果,可明显降低框架结构的振动频率,其中马氏体CuZnAl形状记忆合金耗能器具有较大的耗能能力,经室温水淬时效7 h处理后减振效果最好.     

颗粒混合种类不同的阻尼器减振特性分析

通过试验的方法,分析了颗粒混合种类不同的阻尼器的减振特性。首先搭建了试验装置,以简支梁为研究对象,在其上安装颗粒阻尼器。用激振器对简支梁进行激振,用加速度传感器测得其加速度响应。试验结果表明:颗粒混合种类不同的阻尼器能够有效地抑制系统共振峰值,对简支梁的共振区域有明显的减振效果;颗粒的混合种类不同,阻尼器的减振性能不同:混合种类为4种时(4、6、8、10)减振效果最好,混合种类为5种时(4、6、8、10、12)减振效果最差。     

被动式电磁阻尼器用于转子振动控制的实验研究

提出了一种无需控制的被动式电磁阻尼器．其采用直流电工作．用于实验转子系统并取得了良好的减振效果。该阻尼器结构简单．性能可靠．有推广应用前景。     

半主动控制方法对海洋平台结构振动控制效果的数值模拟及试验对比研究

采用半主动控制方法对海洋平台的振动进行控制,以一典型导管架式海洋平台为原型,根据动力相似准则按1∶ 50 比例设计海洋平台结构模型,以磁流变阻尼器为控制装置设计半主动控制系统,进行多工况减振效果的数值模拟,在此基础上,进行波浪水池试验研究,对比分析半主动控制系统控制效果的数值模拟结果与试验结果,讨论磁流变阻尼器自身刚度、质量对平台动力响应及减振效果的影响,给出磁流变阻尼器半主动控制系统对海洋平台结构振动的减振特点.     

基于闭环PID控制的磁流变液阻尼减振器减振性能测试

针对某结构的振动特性及磁流变液阻尼减振器的工作方式,设计了一套用于检测其磁流变液阻尼器减振效果的测试系统,根据传感器检测到结构的振动信号输入到计算机和磁流变液阻尼减振器的控制器,通过PID方法控制伺服电机的回转速度和方向及外界磁场强度,从而改变输出控制力和阻尼的大小.试验表明,采用该方法,达到了降低结构响应振幅值的目的,提高磁流变液阻尼器的减振控制性能.     

基于改进遗传算法的TMD阻尼器的优化布置

调谐质量阻尼器被广泛应用于高耸结构振动控制。为了提高阻尼器的减振效果,基于安全性要求,建立等效二次型性能指标;通过改进遗传算法,求得TMD阻尼器的最佳安装位置,从而提高TMD减振系统的减振效果。最后通过仿真实验验证优化的意义,并得出一些结论:对于塔筒结构减振控制,不仅要针对低阶振型进行控制,高阶振型的扭转振动也不容忽视。     

磁流变液减振器

磁流变液是一种新型的智能材料。磁流变液的快速流变性能使其广泛用于制造减振阻尼器、制动器、离合器、抛光装置和液压阀等。本文主要介绍了磁流变液在减振器上的应用。     

冷带轧机减振装置减振性能的试验研究

为控制高速冷轧机垂直于轧制方向的辊系颤振，研制出了一种新型的干摩擦阻尼减振装置。本文对该装置的减振性能进行了较为深入的试验研究。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.