基于柔性模块和产品族的液压机快速设计

为使液压机设计快速响应市场需求,提出了基于柔性模块和产品族的液压机快速设计理论。柔性模块是对产品结构用参数化和模块划分得到的一组具有典型模块接口的参数化模型,产品族是具有相似功能和结构的一类产品的总和。在对液压机进行柔性模块划分和产品族规划的基础上,以上梁模块为例说明了产品快速设计的方法和过程。     

液压机广义模块化产品族建模技术的研究

根据广义模块化设计原理,阐述了柔性模块以及柔性元结构等概念,并对广义模块化产品族作了整体规划,提出了以柔性模块为基础构建广义模块化产品族的思想,并结合整体框架式液压机的实例,分析了广义模块化产品族的具体创建过程.     

基于CBR的整体框架式液压机广义模块化产品族建模

将虚拟柔性模块引入广义模块化设计,通过模块的划分与规划,实现了结构复杂且不可再分的一类机械产品的广义模块化产品族设计,拓宽了广义模块化设计的适用范围;采用基于实例推理的方法,建立了整体框架式液压机的产品族和虚拟柔性模块族,为该类机械产品的快速设计提供了理论和技术支持.     

面向产品族演进的模块通用性研究

模块通用性程度的度量对模块化产品族设计或再设计以及演进过程具有重要的意义。分别从基于零部件的通用性指标和面向参数化产品族的通用性指标两个方面进行研究现状的分析,进一步指出了模块通用性与产品族演进关系。在此基础上,提出了基于模块化产品族结构模型的模块通用性指标,即由模块化产品族的模块功能、结构和特征参数三层要素合成,可以分别实现单个模块通用性和模块化产品族整体通用性的衡量,最后以轮式装载机产品族为例说明该方法的有效性。     

基于pareto方法的多目标柔性车间调度问题的研究（英文）

多目标柔性车间调度问题一直是一个学术的难题,关于并行机的问题更是很少讨论。建立了基于并行机的多目标柔性车间调度的数学模型,目标函数为最小化最大完工时间和加工成本。与以往智能优化算法不一样的是,提出了一种基于pareto的简单优化算法。该算法主要包括两个模块:加工顺序模块和机器选择模块,其中机器选择模块采用了基于pareto优化算法。最后,数字实验表明了该算法的正确性和有效性。     

模块化产品族模型的研究

在产品族的四视图模型上,添加组合模型,得到由需求模型、功能模型、原理模型、结构模型和组合模型组成的产品族五视图模型.基于该模型,分别针对产品设计的三种类型,提出了三种模块化产品族的多视图模型.多视图模型中的每个模型都由通用块、变型块和定制块组成,且在结构模型中,综合考虑产品全生命周期的因素,对产品族进行模块划分,得到了模块化的产品族模型.最后通过一个实例对提出的方法进行验证.     

基于pareto方法的多目标柔性车间调度问题的研究

多目标柔性车间调度问题一直是一个学术的难题,关于并行机的问题更是很少讨论.建立了基于并行机的多目标柔性车间调度的数学模型,目标函数为最小化最大完工时间和加工成本.与以往智能优化算法不一样的是,提出了一种基于pareto的简单优化算法.该算法主要包括两个模块:加工顺序模块和机器选择模块,其中机器选择模块采用了基于pare-to优化算法.最后,数字实验表明了该算法的正确性和有效性.     

基于柔性模块的机械产品CAD/CAPP建模

广义模块化设计是针对结构分级特性不明显的大型机械产品提出的,其核心是柔性模块的创建,文章根据广义模块化设计的思想,构建了基于特征的柔性模块CAD/CAPP集成模型;建立了柔性模块基于工艺模板的CAD/CAPP映射模型;并通过实例验证了其可行性。为机械产品的快速设计/制造提供了有利的保障。     

面向广义模块化设计/制造的产品族动态模型研究

通过分析面向产品快速响应设计/制造的产品模型的特点,根据公理化设计理论,构建了面向广义模块化设计的产品族动态模型。通过对产品设计/制造过程的分析,分别建立了基于广义模块化的概念设计子模型、基于功能-结构映射的结构设计子模型和基于特征的柔性模块定义子模型,三者结合,满足了产品全生命周期各个阶段对信息的需求。     

基于改进粒子群算法的知识主动推送模型

为解决机械产品智能制造过程中知识的主动推送问题,实现智能化制造中知识资源的优化配置,提出了一种基于改进粒子群算法的知识推送模型。首先以机械产品为对象,构建知识推送模型框架,阐述各个子模块的具体特征信息和功能;其次,对推送过程中的概念知识进行重新定义,并加入到新的知识网络模型中;最后提出了改进粒子群算法,对知识推送匹配过程实施优化。并以底座类零件产品为例进行验证,结果表明该方法有效的提高了检索能力,具有较好的推送效果。     

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.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

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.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。