基于AMESim的旋转冲击型锚杆钻机液压驱动控制系统设计与建模仿真分析

设计了旋转冲击型锚杆钻机液压驱动控制系统,分析锚杆钻机工作时,液压冲击系统、推进系统、回转机构(转钎)液压回路及钻机防卡钎回路的工作原理,根据抽象设计变量理论,推导出锚杆钻机性能参数冲击能E、冲击频率f和输出功率N与液压冲击器工作流量Q(或工作压力p)及活塞回程加速行程Sj的关系,采用AMESim软件对其进行建模仿真,根据仿真曲线分析了锚杆钻机在冲击钻进时,系统工作压力和推进力对液压冲击器活塞行程、冲击能、冲击频率和冲击器功率的影响。仿真结果验证了液压驱动控制系统设计的合理性和可行性,为锚杆钻机液压驱动系统设计提供了理论基础。     

冲击回转机载型锚杆钻机液压系统设计与AMESim建模仿真分析

设计冲击回转机载型锚杆钻机液压系统,分析其工作原理,采用AMESim软件对该系统进行建模仿真,根据仿真曲线分析锚杆钻机在冲击回转钻进时,推进系统推进力及液压缸工作油压对液压冲击器活塞行程、冲击能、冲击频率和冲击器功率的影响。仿真结果验证了液压系统设计的合理性和可行性,为冲击回转机载型锚杆钻机液压系统设计提供了理论基础。     

液压冲击器氮气室预充压力对冲击性能的影响研究

在分析液压冲击器工作原理及特点的基础上,建立液压冲击器系统的非线性数学模型。运用MATLAB/Simulink分别对液压冲击器的回程加速过程和冲程过程进行仿真研究,分析氮气室预充压力对冲击器冲击性能的影响程度。结果表明:氮气室预充压力过大,会导致液压油不能推动活塞进行回程,液压冲击器起动不了;压力过小,则很容易使冲击压力升不上去,冲击能小。     

基于FLOWMASTER的液压冲击器动态特性仿真研究

在分析了液压冲击器工作原理的基础上,利用一维流体仿真软件FlOWMASTER搭建了气液联合式液压冲击器的仿真模型。结合仿真结果,分析冲击活塞的运动规律以及压力、流量的变化情况,为液压冲击机构的非线性模型研究提供了参考。基于FlOWMASTER的仿真为研究液压冲击器工作机理、提高液压冲击器工作性能和优化系统参数提供了一种可行的理论方法。     

基于AMESim的锚杆钻机顶驱双动力装置的液压系统仿真研究

为使液压锚杆钻机顶驱双动力装置的液压系统各动力部件和执行部件的参数得到合理匹配,采用AMESim软件对液压系统进行建模仿真,并得到了合理的设计计算方法和满意的仿真结果,为锚杆钻机的液压系统设计提供了可靠的理论依据.     

基于PLC、VVVF和HMI的无级变行程锚杆钻机液压驱动控制系统改造

用西门子S7-200 PLC、VVVF和HMI对无级变行程液压锚杆钻机液压驱动控制系统进行改造。分析系统的控制原理,设计系统流程图及软件程序,给出改造后PLC端子接线图。实验结果表明:该控制系统能实现冲击能、冲击频率及位移的自动连续无级调节和最优匹配;同时结合人机界面HMI的应用,实现系统的状态可视化和控制智能化。     

基于PLC和HMI的液压锚杆钻机变频调速控制系统改造

用西门子S7-200 PLC、变频器和人机界面,对某型号液压锚杆钻机冲击回转电气控制系统进行改造。分析系统的控制原理,设计系统流程图及软件程序,给出改造后PLC端子接线图。运行结果证明:改造后控制系统工作可靠,操作方便直观,故障率低,提高了工效。     

基于AMESim的履带式底板锚杆钻机液压系统动态特性研究

随着煤矿开采的加速及矿井深度的不断加深,深部岩土应力会对软岩巷道底板造成破坏,带来较大的安全隐患。履带式底板锚杆钻机是近年来针对巷道底板支护形成的锚杆钻孔设备,对其液压系统进行优化设计与研究,并基于AMESim软件对其回转回路、行走回路和钻进回路进行仿真分析,得到各个回路的压力及流量的动态特性曲线。结果表明:所设计的液压系统能有效保证两个行走马达的同步性能,并具有调速广、波动小等优势,为现有履带式底板锚杆钻机液压系统的改进提供了参考。     

基于微机控制的液压冲击器

传统液压冲击器的冲击能参数调整需在2～3个挡位之间以手动操作的方式进行,且冲击能与冲击频率间的调整具有关联性.参数调整时,液压冲击器需停止工作.为改变这种状态,开发了新型基于微机控制的液压冲击器DBS300.该新型液压冲击器采用模糊控制策略实现控制,在拥有最大300 J冲击能情况下,其可实现冲击频率在0～6Hz间的独立调整.工作中可依据每次冲击后活塞不同反弹速度引起的后部气腔压力变化率来判别被冲击物体特性的改变.依据被冲击物体特性变化,新型冲击器可对冲击能或冲击频率实现独立自我调整,由此可提高冲击破碎工作效率,并具有对冲击器载具功率特性变化的良好适应能力.     

基于微机控制的液压冲击器（英文）

传统液压冲击器的冲击能参数调整需在2~3个挡位之间以手动操作的方式进行,且冲击能与冲击频率间的调整具有关联性。参数调整时,液压冲击器需停止工作。为改变这种状态,开发了新型基于微机控制的液压冲击器DBS300。该新型液压冲击器采用模糊控制策略实现控制,在拥有最大300 J冲击能情况下,其可实现冲击频率在0~6 Hz间的独立调整。工作中可依据每次冲击后活塞不同反弹速度引起的后部气腔压力变化率来判别被冲击物体特性的改变。依据被冲击物体特性变化,新型冲击器可对冲击能或冲击频率实现独立自我调整,由此可提高冲击破碎工作效率,并具有对冲击器载具功率特性变化的良好适应能力。     

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.