新型六臂井径测井仪分动式推靠系统研究及运动学分析

井径测井仪是一种测量井筒直径大小的井下工具,国内测量裸眼井大部分以三臂、四臂为主。利用Pro/E对分动式六臂井径测井仪进行结构设计,分析了新型六臂井径测井仪的运动状态,得出分动式推靠系统有打开和测量两种运动状态。建立了分动式推靠系统两种状态的数学模型,并运用封闭矢量多边形投影法进行了运动特性分析。对分动式推靠系统中阿基米德螺旋线型推靠臂进行结构参数化设计及凸轮运动特性分析。在Adams软件中对分动式推靠系统打开和测量状态进行参数化建模和运动仿真,得出了推靠臂、活塞杆的运动轨迹曲线,验证了其机构运动规律和状态,为后续二次优化提供了有效的参考依据。     

双向驱动井径测井仪推靠系统工作行为分析

针对单向驱动井径测井仪存在的启动响应慢、速度集中和初始运动冲击等问题,提出一种具有双向驱动特征的新型结构井径测井仪,并对其推靠系统(实现测量臂伸缩)双向驱动过程进行矢量化建模求解及工作行为分析(运动性能仿真、测量性能仿真)。首先进行双向驱动测井仪推靠系统物理建模和理论研究,以双驱动丝杠系统参数(速度、位移)为输入,采用复数矢量法对测井仪推靠系统运动性能参数(位移、速度、加速度)进行参数化表征;然后以实际双驱动推靠系统为对象进行实例分析,对其运动特性进行理论求解,得到推靠杆端口和推靠销钉的运动曲线,并对双驱动速度匹配特性进行研究;最后基于ADAMS进行测井仪工作行为分析,将仿真与理论结果进行对比,结果表明推靠系统仿真运动曲线与理论解析曲线具有较高的吻合度,证明了测井仪推靠系统矢量化建模求解的正确性。     

八杆压力机的参数化设计研究

本文以八杆压力机传动机构为研究对象,通过分析八杆机构的几何模型,研究各参数间的数学关系表达式,建立各关键点的坐标表达式即可观察任意时刻各个点及杆件的位置变化,从而实现机构的运动仿真,提高了设计效率。     

一种手控拾发球机器人的设计

本文阐述了一种集拾球、升球、发球功能于一身,用于辅助球类训练的一种机器人设计。并建立了拾球、发球的运动模型及在该模型下分析了球的运动特性。该机器人主要由拾球机构、升球机构、发球机构组成。     

曲柄滑块机构的计算机辅助分析与模拟

精确地推导出结点偏置曲柄滑块机构的运动分析和受力分析的通用计算公式，并运用Ｔｒｕｅ－Ｂａｓｉｃ语言开发了曲柄压力机工作机构的计算机辅助分析与模拟软件。此软件采用中文人机对话方式，能够准确、迅速、直观、方便地确定出合埋的机构结构参数并得到检验。     

钢管端面铣头倒棱机夹紧机构的优化设计

夹紧机构是全自动钢管端面铣头倒棱机的重要组成部分,它要对平头倒棱的钢管夹紧,保证钢管在加工的过程中不发生振动、位移和周向转动。本文对夹紧机构进行了系统的研究,分析了各杆件之间的参数关系,并运用ADAMS软件对夹紧机构进行优化设计。通过分析,在不改变夹紧机构整体尺寸、仅改变内部杆件尺寸的情况下,气缸优化后的最大推进力减少了36．0％,平均推进力减少了21．0％,大大节省了能源。     

曲柄滑块机构的计算机辅助分析与模拟

精确地推导出结点偏置曲柄滑块机构的运动分析和受力分析的通用计算公式，并运用Ｔｒｕｅ－Ｂａｓｉｃ语言开发了曲柄压力机工作机构的计算机辅助分析与模拟软件。此软件采用中文人机对话方式，能够准确，迅速，直观，方便地确定出合理的机构结构参数并得到检验。     

基于Pro／Mechanism的仿生膝关节优化设计与运动仿真研究

设计了用于数字化三维人体模型或假肢的四连杆膝关节,为了达到理想的运动效果,以膝机构瞬心坐标实际值与理想值之差最小,即膝机构的实际瞬心曲线与理想的膝关节瞬心轨迹相一致为目标函数,在五维设计空间中求得一组最优解,利用Pro/E具有几何约束和尺寸驱动等参数化设计功能,无需进行烦琐复杂的公式推导即可建立满足约束要求的数学模型,并应用Pro/E的多目标设计研究功能求得满足运动要求的杆件参数,在此基础上进行膝关节机构的三维造型及装配,进而在Pro/Mechanism环境下对仿生膝关节杆机构进行运动仿真.     

汽车起重机回转机构动态仿真

分析了汽车起重机回转系统工作原理,在此基础上建立AMESim仿真模型,采用该模型对汽车起重机回转机构动力学特性进行了模拟仿真及分析,研究各运动参数、系统匹配特性对回转特性的影响,并对如何改善系统的性能提出了建议。     

永磁吸附履带式船舶爬壁机器人结构设计

分析了一种永磁吸附履带式船舶爬壁机器人结构及工作原理。通过交流伺服电机驱动的永磁吸附履带机构使机器人能完成垂向爬壁的运动功能。为提高机器人的负载能力和越障能力,结构上采用了新型的永磁万向轮辅助吸附机构和从动轮浮动机构。研究中分析了永磁吸附履带爬壁机构的力学状态。通过对吸附系统的磁力仿真及磁力实验分析,合理设计了永磁吸附履带爬壁机器人吸附单元结构形式和电力驱动系统参数。     

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。