升沉补偿模拟试验系统的设计与实验研究

提出和研制了深海采矿扬矿管的主动型升沉补偿模拟试验系统，实现了采矿船的升沉模拟和升沉补偿模拟，并进行了实验研究。实验的结果证明，采用电液比例阀控缸执行机构进行主动升沉补偿的方案是可行的和有效的，采用高性能的电液比例方向阀和合适的控制策略可以获得很高的升沉补偿精度。     

主动式钻柱升沉补偿系统模拟实验及仿真

根据主动式钻柱升沉补偿系统的工作原理,设计并搭建了主动式钻柱升沉补偿系统模拟实验台,利用AMESim软件建立实验台模型并得到补偿缸缸体和活塞杆的位移仿真曲线,利用Matlab／Simulink的xPC Target模块搭建实时控制系统并进行实验。结果表明,同一组PID参数下的仿真结果和实验结果具有较好的一致性,AMESim和Matlab／Simulink软件的应用可以提高升沉补偿系统的设计效率。     

基于AMESim的半主动式升沉补偿系统仿真研究

为进一步研究半主动式升沉补偿的补偿工作机制,在对半主动式升沉补偿装置补偿原理分析的基础上,对装置中的气液储能器和主动补偿缸进行了力学分析和流量连续性分析,并基于AMESim软件对补偿系统进行建模和仿真分析。结果表明:补偿过程中大钩位移随时间变化范围较小,处于小幅值正弦波动范围内,系统能耗曲线近似呈线性上升趋势以及气液储能器压力曲线变化整体趋于平稳。该系统仿真结果能为半主动式升沉补偿装置的设计改进和技术发展提供参考,进一步提高系统的补偿效率和降低能耗。     

复合液压缸式半主动升沉补偿系统建模及仿真

为提高深海有缆水下机器人吊放作业的安全性,提出一种复合液压缸式半主动升沉补偿系统,介绍系统的工作原理,并利用AMESim分别建立了系统在被动升沉补偿模式与半主动升沉补偿模式下的仿真模型。对比分析了不同升沉频率下系统的补偿性能和补偿过程中复合液压缸活塞位移与蓄能器压力的变化规律。分析结果表明,所提出的半主动升沉补偿系统能有效降低周期性母船升沉运动对铠缆张力和中继器位移的影响。     

主动式钻柱升沉补偿模拟实验台控制系统设计

根据主动式钻柱升沉补偿系统控制原理,设计并搭建了主动式钻柱升沉补偿系统模拟实验台。利用Matlab/Simulink的x PC target模块搭建实时控制系统,将模糊PID控制器应用在升沉补偿控制系统中,并进行了实验。利用Lab VIEW软件开发了上位机界面。结果表明:基于模糊PID的控制系统具有良好的补偿性能,能够补偿高低不同频率的升沉运动。     

重型扬矿管主动升沉补偿系统的设计与仿真研究

本文设计了一种采用电液比例方向阀控制的重型扬矿管主动升沉补偿系统，利用SIMULINK和功率键合图建立了升沉补偿系统的仿真模型，对系统的静动态特性进行了仿真研究，分析了其对控制策略的要求。     

天车式半主动钻柱升沉补偿系统多学科仿真分析

为了对天车式半主动钻柱升沉补偿系统样机设计方案进行原理验证,基于SimulationX多学科仿真软件构建了液气回路和多体机械系统联动模型,分别针对被动补偿工况、主被动联合工况和液压介质发生泄漏的工况开展动态响应分析研究。研究表明:该天车式半主动钻柱升沉补偿系统的补偿精度、蓄能器压力波动、被动补偿液压缸结构稳定性达到设计目标和规范的要求。液压介质泄漏量较小时,系统仍能保持补偿功能,符合船级社相关规范的要求。研究结果为我国天车式半主动钻柱升沉补偿系统的研制提供参考。     

主动式波浪补偿液压驱动系统的仿真与实验

以主动式波浪补偿液压驱动系统为研究对象,对整个波浪补偿的电气控制系统进行设计,建立主动式波浪补偿液压驱动系统的数学模型,推导出主动式波浪补偿驱动系统的传递函数,引入PDF(伪微分)算法。运用MATLAB/Simulink对波浪补偿驱动系统的数学模型进行仿真分析,推断出在整个主动式波浪补偿驱动系统中采用PDF(伪微分)控制算法系统响应性能完全满足系统要求。最后通过电机模拟液压驱动系统,根据实验结果来验证PDF控制的优越性。     

基于AMESim的浮式钻井平台钻柱升沉补偿系统仿真研究

针对海浪升沉运动对钻柱和钻压的影响,设计基于电液比例阀控制非对称油缸的海洋浮式钻井平台钻柱升沉补偿系统。通过对系统中电液比例阀和液压缸进行分析,搭建了基于AMESim软件的主动补偿和半主动补偿系统仿真模型,运用PID控制算法进行仿真研究。仿真结果表明,设计的补偿系统具有较好的补偿效果。该模型可为升沉补偿系统研究提供参考。     

水下物体的超声波定位系统的研究

研究了一种基于相关分析方法的超声波水下定位系统,讨论了其主要原理及其设计方法,并进行了前期试验,通过在空气中的模拟检测验证了该方法在原理上的可行性,同时精度能达到设计时的要求,取得了预期的效果。该方法经改进后,可应用于深海采矿升沉补偿系统中,为采矿船提供实时、准确的升沉位移数值。     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.