基于ANSYS的三轮摩托车车架的轻量化设计（英文）

为了减轻三轮摩托车车架重量,优化车架结构,采用有限元理论的方法,在不同工况下对车架进行载荷仿真,分析车架应力和应变;利用ANSYS软件的Design Explorer模块,研究车架参数轻量化设计方法,获得车架轻量化设计方案。该方法对三轮摩托车的车架结构进行优化,为车架的结构改进和轻量化设计提供理论依据。     

轻型载货汽车底盘车架轻量化优化设计

为了推广高强结构钢的应用领域,文章以某轻型载货汽车底盘车架为研究对象实现车架高强轻量化优化设计。根据已有设计经验和市场反馈对现有车架提出初步结构优化方案,建立所有车架有限元模型,通过有限元仿真分析计算各车架方案的动力学特性、刚度和强度力学性能;以解决车架存在的振动、强度问题和车架轻量化为目标,通过车架仿真分析结果的对比和综合评价,最终确定可行的车架轻量化优化方案。     

载货汽车车架轻量化评价方法及优化设计

探讨了载货汽车车架轻量化评价问题,提出了载货汽车车架轻量化优化设计评价方法,并以国内某轻卡车架轻量化优化设计为例,对轻量化优化改进后的车架进行了有限元强度、刚度及模态分析。同时,通过台架试验对其结果进行了试验验证,得出了有限元分析与试验验证均在误差范围内的结果,说明了该评价方法的正确性,此评价方法为载货汽车轻量化评价提供了依据。而在生产制造方面,对车架进行了成形工艺的研究,优化了生产工艺及设备,提高了车架制造精度,为车架的轻量化提供了有力保障。     

轨轮式半自动双侧浇注机轻量化设计

以新型轨轮式半自动双侧浇注机为研究对象,对浇注机主要承载部件车架体以及浇包支架系统进行轻量化设计。基于ANSYS Workbench的优化设计功能,以车架体总重量为目标函数,总变形量为约束函数,各部分结构的截面尺寸为优化变量,对车架体进行优化设计;对浇包支架系统进行应力及变形分析,在保障工作安全性的基础上确定其轻量化部位,且在薄弱环节进行优化加强处理。优化后的浇注机在满足工作性能的基础上减轻了整体重量,为浇注机其他方向的优化提供了参考依据。     

轿车副车架轻量化技术研究及应用

文章将多工况强度分析方法与拓扑优化技术相结合,制定了基于刚度目标及应力约束的轿车副车架结构优化分析流程,并对几种车型的副车架分别进行了结构强度评价分析、轻量化优化分析。工程实际应用表明,采用多工况强度分析方法,能够准确地预测副车架强度薄弱部位,CAE分析与试验结果吻合;采用拓扑优化方法,选取适当的优化参数,可以得到该文给出的减重约15%、符合制造工艺要求的实用减重方案,并适用于全新副车架的概念模型设计,具有较为重要的学术价值及工程实际意义。     

压铸镁合金摩托车车架的受力分析

对渝安XGJ150-23越野摩托车车架进行结构再设计,在满足强度、刚度要求下,将钢结构车架设计成适合压铸工艺的镁合金车架,并抽象建立了车架的简化力学模型;然后在摩托车3个极限服役工况下,对车架的最大应力应变进行了有限元分析和校核,结果显示车架在最大负载下的最大应力值为59MPa,应变最大值为1.38mm,远低于材料的许用应力,满足安全使用的要求。     

换辊小车横移车架结构的多目标优化设计

为了保证换辊小车横移车架刚度在符合要求的前提下达到轻量化的要求,提出了基于重量和刚度为目标函数的横移车架多目标优化设计方法。首先,对横移车架进行了静态特性分析,得到换辊时横移车架的应力分布和变形情况;然后,建立由设计变量所决定的车架重量和刚度的多目标优化数学模型,通过中心复合试验设计法选取合适的分析样本点,并在ANSYS Workbench软件中对样本点处的静态特性进行计算和分析;最后,为了降低多目标优化计算量,先通过Shifted Hamersley抽样技术产生一个次优的初始解集,再运用多目标遗传算法对横移车架的质量和最大变形进行多目标优化获得Pareto优化解集。结果表明,优化后横移车架最大变形量减少10%,重量减小3%,并且车架变形及应力分布更加合理。     

大型薄壁整体精密铸造摩托车车架开发

在提高摩托车车架设计制造品质的目标下,以某型焊接越野摩托车车架为原型,通过合理设计车架结构和铸造工艺,开发了整体精密铸造成形的摩托车车架。有限元分析表明,整体成形车架在极限承载工况下的强度和刚度、自由模态频率明显优于原车架;试制的车架品质优良,疲劳寿命比原车架明显延长且减重5%。结果表明,将大型薄壁整体铸造技术应用于车架类产品,可以提高其品质,降低成本。     

全铝合金越野摩托车车架的结构设计与研究

车架是越野摩托车的主要受力部件,要求具有足够的强度和刚度且质量轻便。依据仿生学原理新设计了车架整体结构,采用常规力学及有限元方法详细分析了摩托车在完成极限动作时车架的受力状况。得出不同落地方式情况下(前轮先落地,后轮先落地,双轮同时落地)车架最大应力值及危险截面出现部位。结果表明,6061铝合金车架具有高的刚性与强度,在上述三种落地方式下车架均不会出现裂纹和变形,能满足设计要求。     

铝合金车架性能分析

采用有限元方法对钢制、铝制车架进行刚度、模态分析,以钢制车架的性能作为铝制车架的设计目标。仿真结果表明:铝制车架比钢制车架轻33 kg,减重比31. 3%,铝制车架与钢制车架的刚度相当;一阶扭转、一阶弯曲都提升3 Hz。最终实现车架轻量化目标,并保证了其使用可靠性。     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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).     

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.