氧化锆基梯度功能材料的设计、制备与性能优化

以石墨为单相润滑剂,设计、制备了梯度层热膨胀系数呈连续变化的氧化锆基功能梯度材料,研究了结构参数与梯度材料力学性能的关系。结果表明:通过调节石墨在复合材料中的空间分布特征,可实现对材料内残余应力大小的调节,进而实现材料力学性能的优化。增大梯度层数和承载层厚度均有利于梯度材料力学性能的提高。梯度指数p为2.5时,材料具有最佳的抗弯强度,抗弯强度可达750 MPa。材料的梯度结构设计实现了陶瓷复合材料的结构/润滑功能一体化。     

梯度功能混凝土复合防护结构抗侵彻性能试验研究

为改善和提升混凝土结构的防护性能,以多层复合防护结构中应力波的传播特性为理论依据并结合梯度功能结构材料基本原理,采用梯度分层化设计方法及多相分层成型法制备技术,设计并制备了一种梯度功能复合防护结构(FGCS).通过对不同弹体侵彻速度下FGCS组靶体和双叠层结构组靶体抗侵彻性能的试验研究,指出弹体成坑面积、成坑深度及侵彻深度与弹体速度间均存在线性的变换关系.同时,相对双叠层结构组靶体,FGCS组靶体表现出优异的抗侵彻性能,且随着弹体侵彻速度的增加,其抗侵彻性能会变得更突出.当弹体速度为950 m/s时,相对双叠层结构组靶体,FGCS组靶体的侵彻深度减少了25.6％.     

玻璃钢／混凝土复合结构设计

论述了玻璃钢/混凝土复合结构的结构设计和材料设计,强调玻璃钢与混凝土间的界面层粘结强度和玻璃钢层内的微裂纹控制是保证复合材料性能的技术关键。并提供了有关设计计算方法。     

公路桥梁伸缩缝过渡区混凝土修复技术研究

桥梁伸缩缝过渡区混凝土性能的优劣不仅对桥梁伸缩缝结构服役性能有着重要的影响,且对行车安全有着直接的影响.首先简要介绍了公路桥梁伸缩缝过渡区混凝土病害的产生机理.然后综合评述了国内外近年来有关公路桥梁伸缩缝过渡区混凝土修复结构和修复材料等最新研究应用成果.最后根据功能/结构一体化设计理念,建立了一种基于功能梯度组合结构设计的超高韧性混凝土快速修复技术,并探讨了其在实际工程中的应用.工程实践表明:这种基于功能梯度组合结构设计的新型快速修复技术实施效果良好,具有广阔的推广应用前景.     

静电纺纳米纤维复合梯度型空气过滤材料的研究进展

概述了静电纺纳米纤维及其复合梯度过滤材料的特性,详述了国内静电纺纳米纤维复合梯度型空气过滤材料的制备、过滤模型理论及数值模拟等研究进展。基于不同纤维层过滤不同粗细颗粒物,每一层纤维网发挥各自独特作用,可采用多种结构和折叠结构复合,增大过滤面积,制备多层梯度的静电纺纳米纤维复合滤材,使滤材具有高效低阻、容尘量大、使用寿命长等特点,是未来空气滤材的重点研发方向;同时应加强过滤模型设计与数值模拟研究,通过滤材的应用数据不断修正模型,促进滤材性能的改进。     

三维缝合结构阻尼复合材料制备与性能研究

通过选用柔性环氧树脂及不同的增强材料,制备三维缝合夹层结构复合材料,得到具备较佳阻尼性能和较高结构强度的复合材料。通过测定三维缝合结构阻尼复合材料的各项性能,得到三维缝合结构的最佳体系为结构层采用环氧树脂复合材料,阻尼层采用芳纶纤维布增强柔性环氧树脂,其阻尼比为3.33%,弯曲模量为14.3GPa,弯曲强度为290MPa,冲击韧性为338k J/m2。     

改性辅助胶凝材料的制备及耐久性能研究

本文通过设计环保型阻锈功能组分,并将矿渣、粉煤灰、硅灰等进行工艺复合,研制改性辅助胶凝材料。同时,通过抗硫酸侵蚀性能、电通量等测试,考察了改性辅助胶凝材料对高强度混凝土耐久性能的影响,结果表明:研制的改性辅助胶凝材料能有效地改善了混凝土的微观结构,并且有着较好的电化学性能,设计的C40混凝土抗硫酸盐侵蚀系数大于1.1,电通量小于500 C,在海洋工程混凝土结构中有着较好的应用前景。     

体外构建壳聚糖/β-甘油磷酸钠/明胶仿生梯度支架

针对软骨特定结构缺损后不能自我修复的特点,通过调控单层原料质量比,构建具有复杂分层结构的壳聚糖/β-甘油磷酸钠/明胶(chitosan/β-sodium glycerophosphates/gelatin,Cs/GP/Gel)仿生复合梯度支架。通过对比物理性能优选适宜比例的支架材料,并将骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)接种到梯度支架上考察其生物相容性。结果表明,Cs/GP/Gel复合梯度支架具有良好的吸水性能[(584.24±3.79)%～(677.47±1.70)%]、孔隙率[(86.34±5.10)%～(95.20±2.86)%]和降解性能[(86.09±2.46)%～(92.48±3.86)%]。扫描电镜(SEM)结果表明,支架材料在纵向维度呈现出明显的生理分层结构和孔径梯度渐进性,可有效模拟真实软骨的天然生理分层结构。比例为9:1:5的Cs/GP/Gel复合梯度支架适于作为骨软骨的支撑材料。对BMSCs-支架复合物Live/Dead染色后发现,细胞在梯度支架材料上存活、分布及伸展良好。该仿生梯度支架为开发新型生物医用材料提供了重要依据。     

新型PLC-GRC复合墙板收缩性能改进试验

针对因材料不同，收缩性能不同导致复合墙板出现开裂问题，提出对优化材料与材料的连接方式和改变装饰层材料厚度对复合墙板收缩性能进行优化。结果表明，PLC-GRC复合墙板受GRC装饰层厚度影响规律相同，连接方式为平接界面连接，GRC装饰层厚度为15mm时，新型PLC-GRC复合墙板收缩性能最优。     

无细观界面过渡区水泥基材料的设计及其性能

为提高混凝土的耐久性,延长其服役寿命,通过对混凝土细观结构的性能优化,设计制备出无细观界面过渡区水泥基材料(meso-defect interface transition zone-free cement-based material,MIF),用于重大工程结构的功能梯度混凝土保护层,并对其抗渗性能、力学性能、体积稳定性以及微细观结构进行了试验及机理探讨.结果表明:相比于普通的混凝土保护层材料,MIF混凝土渗透性极低,氯离子扩散系数减小1个数量级,而材料的使用寿命增长10倍以上.材料的力学性能及体积稳定性优良,完全满足工程需要且整体结构的体积变形匹配性良好,表面未见开裂.MIF混凝土微细观结构均匀、致密.     

低温多股流板翅式换热器设计优化方法研究进展

针对多股流体流动换热、复杂翅片结构优化、多重通道排布匹配以及低温工程应用等特点,本文归纳分析了低温多股流板翅式换热器结构设计中凸显的流股换热匹配、通道分配排列、多物理场叠加以及低温特殊工况下的应用等问题。总结了在通道结构优化与零部件设计中,通过翅片通道传热流动特性及相关性能评价方法来指导结构选型。文章还深入分析国内外现状,讨论了板翅式换热器的研究热点与发展方向。文章指出低温多股流板翅式换热器应用于大型空分等石化工业流程中优势明显,可显著提高气体液化率,降低实际能耗,进而提升系统运行效率。因此,对于实际应用中可能遇到的设计问题,应考虑结合局部换热网络与多流股匹配、翅片结构设计与通道排列算法优化、多场仿真与试验研究等手段形成合理优化方法和设计框架,来摆脱目前传统经验试凑所带来的限制。     

基于Optistruct的碳纤维复合材料包装箱结构优化设计

本文基于Optistruct结构优化技术,采用碳纤维复合材料进行了某特种包装箱的结构设计。结合包装箱结构设计的技术指标要求,提出了多阶段的优化设计方法。多阶段优化设计包括形貌优化、尺寸优化和铺层优化。在箱体的概念设计阶段,通过形貌优化获得了满足箱体刚度的加筋结构;针对基于铺层的碳纤维复合材料的可设计性能,在箱体的细节设计阶段,通过尺寸优化和铺层优化分别获得了复合材料各个铺层角度的最佳铺层厚度尺寸和复合材料箱体的最佳铺层方式。最终,通过有限元数值分析验算,结构设计的结果满足设计要求。     

Fabrication of alumina ceramics with functional gradient structures by digital light processing 3D printing technology

Alumina ceramics with different unit numbers and gradient modes were prepared by digital light processing (DLP) 3D printing technology. The side length of each functional gradient structure was 10 mm, the porosity ratio was controlled to 70%, and the number of units were (1 × 1 × 1 unit) and (2 × 2 × 2 unit) respectively. The different gradient modes were named FCC, GFCC-1, GFCC-2 and GFCC-3. SEM, XRD, and other characterization methods proved that these gradient structures of alumina ceramics had only α-Al2O3 phase and good surface morphology. The mechanical properties and energy absorption properties of alumina ceramics with different functional gradient structures were studied by compression test. The results show that the gradient structure with 1 × 1 × 1 unit has better mechanical properties and energy absorption properties when the number of units is different. When the number of units is the same, GFCC-2 and GFCC-3 gradient structures have better compressive performance and energy absorption potential than FCC structures. The GFCC-2 gradient structure with 1 × 1 × 1 unit has a maximum compressive strength of 19.62 MPa and a maximum energy absorption value of 2.72 × 105 J/m3. The good performance of such functional gradient structures can provide new ideas for the design of lightweight and compressive energy absorption structures in the future.     

Hierarchical structure of injection-molded bars of HDPE/MWCNTs composites with novel nanohybrid shish-kebab

Injection-molded products usually show hierarchical structure from skin to core due to the existence of shear gradient and temperature gradient. Investigating the hierarchical structure is helpful to better understand the structure-property relationship of injection-molded sample, which is important for design and preparation of polymer products with high performance. In this work, the hierarchical structures of injection-molded bars of high-density polyethylene (HDPE)/multi-walled carbon nanotubes (MWCNTs) composite were explored by examining the microstructure and crystal morphology, layer by layer, along the sample thickness, using SEM, DSC and 2D-WAXS. To enhance the shear effect, a so-called dynamic packing injection molding (DPIM) technique was used to prepare the molded bar with high orientation level. Interestingly, SEM revealed that in the skin and core zones, the lamellae of PE anchored randomly on the surface of MWCNTs, while well-defined nanohybrid shish-kebab (NHSK) entities, in which fibrillous carbon nanotubes (CNTs) act as shish while HDPE lamellae act as kebab, exist in the oriented zone. The changed NHSK crystal structure along the thickness direction of molded bar is considered as due to the shear gradient and thermal gradient in injection molding. And the underlying origin of in situ formation of NHSK under shear effects is discussed based on experimental observations.     

质子交换膜燃料电池膜电极制备方法的研究进展

燃料电池技术作为一种绿色能源技术,在减少能源消耗、环境污染等方面具有巨大潜力。膜电极（MEA）是质子交换膜燃料电池（PEMFC）的核心部件,MEA中电化学反应的顺利进行需要各功能层的协调配合,MEA各功能层涉及的传质、导电、导质子、催化等方面均影响燃料电池的性能。根据制备方法,可以将MEA分为催化剂涂敷基底（CCS）型MEA、催化剂涂敷膜（CCM）型MEA、有序化MEA和一体化MEA。MEA的性能不仅由催化剂本身载量决定,也受其结构设计和制备工艺的影响。本文介绍了MEA制备过程中常见的改进方法,分别从催化剂喷涂、刮涂、模槽挤出涂覆方式,催化剂浆料组成中Nafion含量和溶剂极性选择,催化层梯度化、图案化及界面结构改进,PEM结构增强、图案化、成膜方式等方面的研究进展进行讨论。但是目前对于MEA各功能层界面间的研究较少,应该注意的是催化层/质子交换膜（PEM）界面以及催化层/气体扩散层（GDL）界面设计也将直接影响MEA的性能。     

基于ANSYS ACP的复合材料潜水器结构设计

基于ANSYS Composite Prep/Post复合材料分析模块研究了潜水器在起吊工况下的结构强度。采用Hill-Tsai强度理论和Tsai-Wu强度理论,对比了两种不同失效准则下的潜水器结构失效形式。对潜水器不同结构区域处碳纤维编织材料的铺层数量进行参数化设置,结合试验设计方法,用合理有效的计算样本得到了复合材料潜水器载体结构的最优设计方案。文中采用的复合材料结构有限元计算与试验设计相结合的方法,对于复合材料工程结构的直接优化具有一定的参考价值。     

Adhesion of graphene oxide on a transparent PET substrate: a study focused on the optimization process

The procedure with the aim to optimize a process of transfer of GO layer, formed by filtration on a PET substrate, was run out in two stages. First, using a Plackett–Burman experimental design strategy was to investigate the most significant technological parameters. Seven types of different interlayer materials (composed either of polymers or smaller organic molecules) were used to improve the quality of the operation. Using a quantitative structure property relationship strategy, it was stated that the hydrogen bonds play a very important role in the quality assurance of the process of GO transfer. However, hydrogen bonds formed between GO sheets and interlayer molecules influence only in the case when these molecules are sufficiently large. SEM images have shown that the morphology of GO layer after transfer is dependent on the interlayer material. Raman spectra revealed typical changes in the structure of GO layer using different interlayer materials. Arrangement of GO sheets in the layer and the structure of the GO single layer can be controlled by using appropriate interlayer materials. It was found that the main parameters, operating the quality of the process of GO transfer are: the thickness of interlayer, the coating thickness, and the temperature. At the second stage, using a simplex optimization strategy, a specific set of optimal values to obtain the best quality during the transfer procedure, was determined.     

Structure and Material Design of High Performance Functional Refractories for High-speed Continuous Casting

Functional refractories,including submerged entry nozzle ( SEN) ,ladle shroud and monolithic stopper, are the key refractories for continuous casting. Driven by the demand of high-speed continuous casting,traditional functional refractories fail to meet the needs of long span life,and high performance functional refractories for continuous casting are increasingly required. Through structure and material design,the performance of functional refractories is significantly improved. In this paper,some research advances on functional refractories for continuous casting were mentioned. Through numerical modeling and hot simulation,the service life of non-preheating ladle shroud was increased from 8 h to more than 12 h. Through the water modeling,the flow patterns in the mold were significantly improved and through hot simulation and material design,the service life and reliability of SEN were also significantly improved.     

锂铝硅玻璃的研究进展

与传统的钠钙硅玻璃和高铝玻璃相比,锂铝硅玻璃具有网络结构致密、弹性模量较高和适宜两步法化学钢化等特点,被视为第三代高强玻璃基板,可用作电子信息产品盖板、航空透明器件以及舰船、特种车辆的观察窗口等。目前,锂铝硅玻璃的研究主要涉及:(1)探究锂铝硅玻璃的“组成-结构-性能”本构关系,为设计优化高性能锂铝硅玻璃提供理论指导和性能预测;(2)改进现有溢流和浮法成型方法和装备,满足大尺寸、多厚度和高尺寸精度锂铝硅玻璃成型需要;(3)研究锂铝硅玻璃的两步法化学增强方法,解决表面压应力和应力层深度同步提升难题,显著提高玻璃强度、硬度和抗跌落性能。本文基于上述三个方面综述了锂铝硅玻璃的国内外研究进展。     

PTA装置部分不锈钢设备设计选材经济性分析

通过对PTA装置中部分奥氏体不锈钢设备设计选材分析,阐明了设备结构设计经济性与节能减排降耗的理念。PTA装置过程设备设计应在遵照国家规范、标准的基础上,充分应用新材料、新技术,改进结构,优化设计。设备选材在满足工艺条件要求、设计强度、刚度和稳定性等安全的前提下,选择尽量简单而经济的结构形式,为再建设项目带来更好的经济效益和社会效益。