风机叶片双轴液压作动器疲劳加载装置设计

设计了双轴液压作动器叶片疲劳加载装置。对翼面向和翼弦向运动耦合问题进行分析,设计加载装置的液压系统,按照工作周期能量守恒原则,进行作动器性能参数匹配,采用蓄能器作为辅助动力源,模糊自整定PID参数对作动器进行控制。试验结果表明:在翼面向振幅维持阶段,液压作动器加载装置能很好地捕捉叶片共振点,并逐步达到共振峰值且维持峰值变化率在试验要求的误差范围内(±5%),达到了较好的控制效果。     

基于直线电机的新型动态加载系统建模与仿真

针对伺服作动器动态性能测试需求,充分发挥电动加载便于安装维护、控制灵活以及直线电机高动态特性的优势,提出由直线电机驱动增力模块,通过机液融合的方式实现小位移、大推力、高频响的动态加载方案。在建立加载系统与伺服作动器系统数学模型的基础上,为提高力加载精度、改善系统稳定性和响应速度,引入多环级联控制与前馈控制的复合控制方案,并基于结构不变性原理通过前馈补偿抑制多余力。MATLAB/Simulink仿真结果表明:提出的伺服作动器动态加载方案与控制策略能够有效改善系统加载性能和抑制多余力,具有良好的工程参考价值。     

风电机组叶片弦向摆锤共振疲劳加载特性分析

针对叶片弦向加载系统,建立系统的弹簧-阻尼模型,利用拉格朗日方程推导出系统的运动微分方程。分析叶片弦向疲劳加载共振能量,对系统进行动力学分析和参数匹配,并完成疲劳加载实验装置测试。试验结果表明:当驱动频率与加载对象固有频率偏差较大,振幅则发生剧烈波动,偏差较小时,加载对象振幅会趋于稳定,为疲劳加载系统应用提供理论依据及试验参考。     

空间对接动力学半物理仿真系统电液伺服作动器设计与研究

针对空间对接半物理仿真系统电液伺服作动器设计问题进行研究,建立了接触碰撞半物理仿真试验系统.从分析空间对接半物理仿真系统建构问题和对接机构的特性入手,提出了运动模拟器电液伺服作动器的设计要求.通过对电液伺服作动器动力机构数学模型展开分析,提出减小电液伺服作动器动态特性相对负载刚度变化的灵敏度的设计方法,并进行了实验验证.     

基于电磁激振的风电叶片双向疲劳加载控制算法研究

针对双向疲劳加载导致的扰动大且叶片惯性大导致控制难度大、精度达不到要求等问题,提出一种基于电磁力驱动的风电叶片双轴疲劳加载新方法。在对该疲劳加载方法研究的基础上,将具有可调增益的模型参考自适应控制算法应用于风电叶片电磁双轴疲劳加载系统。该算法可根据电磁疲劳加载系统的内部频率变化不断地跟踪参考模型的输出。结合先前研究成果,建立风电叶片电磁力驱动的双轴疲劳加载模型试验平台,在现场试验对自适应算法的控制效果进行验证。结果表明：在挥舞方向,可调增益的模型参考自适应控制算法平均跟踪误差在10%以内,摆振方向为7%以内;相较于传统PID算法,该算法具有更好的跟踪能力、鲁棒性、抗扰动能力,控制性能得到了很大的提升。     

新型大功率低噪声直驱式液压作动器设计与仿真

针对现有液压作动器的不足,设计了新型大功率低噪声直驱式液压作动器,该系统采用内函式变速电机泵功率单元及换向阀联合控制,在AMESim仿真平台软件中建立了模型,并进行了仿真分析.仿真结果表明,该作动器具有良好的动态性能.     

十字形薄板双轴疲劳试验的设计与实现

基于双轴疲劳试验数据较少的现状,采用双通道载荷控制技术,将电液伺服材料试验机INSTRON 1251系统横向作动器与纵向作动器组合,研制了十字形薄板试样双轴疲劳试验测试工装夹具,设计了十字形薄板试样双轴疲劳试验系统,达到了十字形薄板试样双轴疲劳试验要求及数据监测记录功能。试验运行表明:该试验设计实现了可靠双轴加载,试验控制精度高,为材料或零件结构设计与强度评估提供了基础技术支持。     

基于直驱式容积控制作动器的倾摆系统研究

针对摆式列车倾摆系统要求,依据直驱式容积控制电液伺服技术完成了作动器结构设计,建立基于AMESim系统的仿真模型.运用ADAMS动力学软件建立摆式列车倾摆机构的动力学模型,并与AMESim软件实现了对倾摆作动系统的联合仿真.仿真结果表明,采用直驱式容积控制电液伺服作动器的倾摆作动系统性能良好,达到了预定的性能指标,能满足摆式列车的要求.     

水下拖曳升沉补偿负载模拟加载系统的设计

提出并设计了一种水下拖曳升沉补偿负载模拟加载系统,通过张力模拟信号发生器对水下拖曳升沉补偿系统的负载理论值进行实时计算,采用电液比例溢流阀控制液压马达驱动加载液压绞车实现对升沉补偿系统的加载.应用Simulink工具建立了液压加载系统的仿真模型,并对其性能进行了仿真研究.仿真结果表明,该负载模拟加载系统能够对水下拖曳升沉补偿系统的负载进行准确模拟.     

某型飞机组合式伺服作动器检测系统设计

为了对某新型飞机组合式伺服作动器进行功能及性能参数测试,设计该伺服作动器检测系统。采用液压弹簧进行加载,由控制计算机自动控制,模拟了伺服作动器的工作环境,可对组合式伺服作动器的伺服阀、LVDT以及相关附件进行测试。同时综合了故障专家维修指导模块,可指导实验过程中出现问题的解决。实践测试表明:该检测系统能有效缩短组合式伺服作动器的测试时间,提高测试效率和检测精度,降低测试成本。     

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.