一种并联液压混合动力系统半实物仿真方法

为缩短产品开发周期,提出一种并联液压混合动力系统半实物仿真方法。通过转矩转速传感器实时采集液压混合动力实物系统的输入/输出扭矩、转速,利用压力传感器实时采集蓄能器压力,根据上位机中实时运行的后向仿真整车及控制策略模型,计算发动机扭矩和转速,实时获得整车循环工况油耗。该方法用到的实物部件少,控制系统简单。对比该方法与计算机仿真方法,结果表明：该方法电力测功机转速跟随误差较小,泵马达转矩、发动机转矩、蓄能器压力和整车油耗变化趋势一致,蓄能器压力和整车油耗误差在10%以内,快速验证了液压混合动力系统模型的准确性和整车控制策略的有效性。     

250 km/h动车组头车底架有限元分析与优化设计

底架作为动车组车体关键承载部件,其结构设计的刚度及强度对整车的安全使用及性能有很大影响。采用ANSYS有限元方法,在整车分析的基础上,对250 km/h动车组底架的结构进行强度分析研究。对底架主要的典型载荷下应力集中部位(牵引梁等)进行局部应力分析并优化,对250 km/h动车组头车车体结构进行了静强度试验。在各工况和载荷作用下,各应力测点的应力及合成应力和位移测点的位移值均小于所用材料的弹性极限,底架结构设计合理。     

三轴汽车气压ABS自适应控制及硬件在环研究

基于LabVIEW和TruckSim搭建了三轴汽车ABS硬件在环平台,通过TruckSim建立了整车的参数化模型,使用LabVIEW并以PXI实时系统为运行环境,可以有效地解决软硬件实时运行的问题,降低了开发周期和成本;在Matlab/Simulink中设计了两种ABS控制策略,并研究了路面对于制动性能的影响,比较了基于路面附着特性辨识设计的模糊PID控制策略与常规PID控制策略的制动效果,并进行了硬件在环试验。试验结果表明:该硬件在环平台有很好的试验效果;基于路面附着特性辨识的模糊PID控制策略能够有效缩短制动距离,同时具有较好的方向稳定性。研究结果为ABS实际控制器的开发提供了依据。     

新型煤矿井下混凝土搅拌车关键技术研究

为了改善煤矿井下混凝土供料的落后状况设计了一种新型煤矿井下用混凝土搅拌车,阐述了该新型煤矿井下混凝土搅拌车设计过程中的关键技术。由于受到煤矿井下巷道高度的限制,搅拌车在满足巷道行驶的前提下,混凝土运送量同样需要达到要求指标。整车设计方案充分考虑了整车通过性,搅拌罐卸料高度、填充率、水平布置罐口密封等环节,并给出设计方案;设计了多功能承载平台,可快速更换工作机构,实现一机多用;研究设计了独立驾驶室旋转操控单元,在视线不佳的煤矿巷道中,实现双向操作;设计了下摆架结构,使得车辆行驶适应煤矿巷道恶劣路面;并在原本紧凑车体上加装了减振系统,降低驾驶室振动加速度,有效缓解驾驶疲劳。该车设计方案可满足煤矿井下混凝土长距离运输,避免了传统材料车运输混凝土存在的离析、分层、漏料、硬化等现象,解决了混凝土供给不及时,路面硬化质量差等问题。     

高铁外交加鞭 中国南车赶上“大时代”

在新一届政府力推下,今年以来＂高铁外交＂效果惊人,中国南车亦成为最大受益者。6月,李克强总理出访欧洲,6月24日,中国南车获得马其顿6列动车组订单。这是中国城际动车组整车产品首次进入欧洲市场,标志着中国的最高端轨道交通装备产品赢得了欧洲市场的认可。     

新型煤矿井下混凝土搅拌车关键技术研究（英文）

为了改善煤矿井下混凝土供料的落后状况设计了一种新型煤矿井下用混凝土搅拌车,阐述了该新型煤矿井下混凝土搅拌车设计过程中的关键技术。由于受到煤矿井下巷道高度的限制,搅拌车在满足巷道行驶的前提下,混凝土运送量同样需要达到要求指标。整车设计方案充分考虑了整车通过性,搅拌罐卸料高度、填充率、水平布置罐口密封等环节,并给出设计方案;设计了多功能承载平台,可快速更换工作机构,实现一机多用;研究设计了独立驾驶室旋转操控单元,在视线不佳的煤矿巷道中,实现双向操作;设计了下摆架结构,使得车辆行驶适应煤矿巷道恶劣路面;并在原本紧凑车体上加装了减振系统,降低驾驶室振动加速度,有效缓解驾驶疲劳。该车设计方案可满足煤矿井下混凝土长距离运输,避免了传统材料车运输混凝土存在的离析、分层、漏料、硬化等现象,解决了混凝土供给不及时,路面硬化质量差等问题。     

基于PID参数模糊自整定控制的电动助力转向系统跟随性研究

针对汽车电动助力转向系统(EPS)对控制系统的高跟踪性、高协调性要求,在分析PID控制及PID参数变化对系统性能影响的基础上,提出用模糊推理方法在动态过程中改变PID参数模糊自整定控制策略.仿真结果表明,所设计的电动转向控制系统具有良好的跟踪性能,较好地保证了控制量的可靠性和系统的实时性.     

高速动车组铝合金车体结构设计

根据高速动车组铝合金车体设计概念的要求,利用头车的空气动力学外形,以动车组动态包络线为约束条件,进行车体断面设计和整车的三维设计,铝合金车体焊接结构的设计符合EN 15085焊接标准,按照标准要求选择车体的母材、焊接材料和设计车体的焊接接头型式.通过对车体的静强度计算和试验数据的分析,验证了头车试验车体的强度符合欧洲标准EN12663,能够满足产品的安全可靠性需求.     

基于磁导引AGV的路径跟踪控制策略研究

随着AGV在物流输送系统中应用场景越来越复杂化,如何提高其路径跟踪精度及系统鲁棒性是目前主要研究内容之一。对此,以前轮舵机转向、后轮速度驱动型磁导引AGV为控制对象,分别设计了前轮转向模糊控制器和后轮速度调节模糊控制器,并使两者协调配合,达到实时根据路况合理调整舵机转角和驱动电机速度的目的。最终在Matlab中进行了仿真分析与验证,实验结果表明该控制策略在提高磁导引AGV路径跟踪精度及系统鲁棒性方面具有一定的可行性和有效性。     

前罩A柱圆弧扣合圆角不顺控制策略

前罩A柱圆弧扣合圆角不顺是前罩总成扣合生产过程中经常出现的一种外观缺陷,为整车精致工艺评价过程中经常被扣分的区域。在各新品项目试制过程中,该问题有整改频次高、涉及环节多、整改难度较大的特点。从工艺过程分析,对扣合圆角不顺产生的原因进行了阐述,并制定了扣合圆角不顺详细控制策略,为后期闭合件扣合过程中圆角不顺问题的整改,提供了解决思路。     

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.