今日更新:Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
Research on ultrasound-assisted low-constraint deformation law and scale effect of ultra-thin fiber metal laminates
Jiajun Yang, Yao Wang, Xuchang Niu, Da Cheng, Kang Liu, Chao Yang, Libin Zhao, Ning Hu
doi:10.1016/j.compositesa.2024.108705
超薄金属纤维层合板超声辅助低约束变形规律及尺度效应研究
Fiber metal laminates (FMLs) are extensively used in large aero components, such as aircraft skins and fuselages. In this study, the thickness of conventional FMLs components are reduced to the micron level, and the deformation behaviors of ultra-thin laminates are investigated thoroughly. These investigations will broaden the applications of FMLs in micro-systems. FMLs formability is a primary factor limiting their widespread applications. While the material flow stress can be reduced substantially through ultrasound-assisted forming with improved formability. Currently, most research on ultrasound-assisted forming is focused on metal micro-forming. Limited studies have addressed the enhancement mechanisms of ultra-thin FMLs. This study focused on developing an ultrasound-assisted test setup. The low-constraint ultra-thin industrial pure titanium grade 1 (TA1)/carbon fiber reinforced polymer (CFRP) laminates are prepared through the interlayer adhesive film addition method. The tensile deformation behavior of laminates is examined by comparing tensile strength, elongation and reduced stress values under various amplitudes, lay-up angles, geometries and grain sizes. The damage mechanisms of laminates under ultrasound assistance are explored through surface and interlayer micro-morphological analyses. The study explains the low-constraint deformation of ultra-thin FMLs under the combined influence of ultrasound assistance and scale effects, thereby providing a theoretical foundation and technical support for ultra-thin FMLs application in the micro-device sector.
金属纤维层压板广泛应用于大型航空部件,如飞机蒙皮和机身。在本研究中,将传统的FMLs组件的厚度降低到微米级,并对超薄层压板的变形行为进行了深入的研究。这些研究将拓宽fml在微系统中的应用。fml的成形性是限制其广泛应用的主要因素。超声辅助成形可显著降低材料流变应力,提高成形性能。目前,超声辅助成形的研究主要集中在金属微成形方面。关于超薄FMLs增强机制的研究有限。本研究的重点是开发一种超声辅助检测装置。采用层间胶膜添加法制备了低约束超薄工业纯钛1级(TA1)/碳纤维增强聚合物(CFRP)层压板。通过比较不同振幅、铺层角度、几何形状和晶粒尺寸下的拉伸强度、伸长率和减小应力值,研究了层压板的拉伸变形行为。通过对复合材料表面和层间微观形貌的分析,探讨了复合材料在超声辅助下的损伤机理。本研究解释了超薄FMLs在超声辅助和尺度效应共同作用下的低约束变形,为超薄FMLs在微器件领域的应用提供了理论基础和技术支持。
Electric field-assisted alignment of carbon nanotubes in the interlayers of CFRP composites to enhance the properties
Jing Xiao, Shuran Li, Mengze Li, Yihan Fu, Ling Yan, Xiaowen Song, Yinglin Ke
doi:10.1016/j.compositesa.2024.108706
电场辅助碳纳米管在CFRP复合材料层间排列以提高其性能
Improving the mechanical properties of carbon fiber reinforced polymer (CFRP) composites with carbon nanotubes has been a challenge due to the lack of control over the distribution and orientation of carbon nanotubes during composite processing. Here we present a novel approach of utilizing a dielectric block to polarize and align interlayer CNTs by applying a bipolar nanosecond pulse superimposed direct current bias (nsPDC) electric field during the curing process of CFRP laminates. The addition of 0.05 wt% multi-walled carbon nanotubes (MWCNTs) resulted in a 138% increase in the initial crack extension and a remarkable 139% increase in the steady state. Based on the microscopic characterization of the fracture surface and the crack extension path, the significant increase in mode I fracture toughness was attributed to the enhancement of the interface and the bridging effect of the aligned carbon nanotubes. Furthermore, testing of the in-plane properties demonstrated no loss and even slight enhancements. The results of this study open up new opportunities for developing composites with significantly enhanced properties.
由于碳纳米管在碳纤维增强聚合物(CFRP)中的分布和取向难以控制,提高CFRP复合材料的力学性能一直是一个挑战。在这里,我们提出了一种利用介电块在CFRP层压板固化过程中施加双极纳秒脉冲叠加直流偏压(nsPDC)电场来极化和排列层间碳纳米管的新方法。添加0.05 wt%的多壁碳纳米管(MWCNTs)可使初始裂纹扩展增加138%,使稳态裂纹扩展显著增加139%。基于断口形貌和裂纹扩展路径的微观表征,I型断裂韧性的显著提高归因于碳纳米管排列界面的增强和桥接效应。此外,平面内性能测试表明没有损失,甚至略有增强。这项研究的结果为开发具有显著增强性能的复合材料开辟了新的机会。
Uncovering catalytic activity of Cu species on boron/nitrogen co–doped carbon nanotubes for efficient hydrogenation of nitroaromatics: beyond the size of metal active center
Jie Zhang, Xiaoxin Zhang, Hui Sun, Lei Shi, Juntao Wei, Deliang Xu, Shu Zhang, Jinqiang Zhang, Shaobin Wang, Hongqi Sun
doi:10.1016/j.compositesb.2025.112112
揭示铜在硼/氮共掺杂碳纳米管上对硝基芳烃高效加氢的催化活性:超越金属活性中心的尺寸
Promising catalysts with high efficiency, easy preparation, and good stability have huge potentials in hydrogenation reactions. In this work, earth–abundant Cu anchored on boron and nitrogen co–doped carbon catalysts (Cu@BNC) were constructed via a simple one–pot calcination approach. The size of resulting Cu species ranging from single atoms, clusters to nanoparticles can be easily controlled through varying the calcination temperature. As–synthesized Cu@BNC catalysts possessed several merits, e.g., preferable nanotubular morphology with large specific area, highly dispersed Cu active sites, and tunable interfacial properties. Taking hydrogenation reduction of nitroaromatics as paradigm, the catalytic performance of Cu@BNC catalysts was dependent not only on the size of Cu species, but also on BNC support effect like suitable surface charge, as well as critical Cuδ+–Nx structures at the metal–support interface. In this regard, the constructed Cu@BNC–900 catalyst with both Cu single atoms and a small amount of clusters exhibited an exceptional rate constant of 0.378 min−1 with the turnover frequency of 0.80 min−1 (even superior to its counterpart containing most single atoms) in 4–nitrophenol reduction, and an excellent recyclability and stability. This work sheds light for rational design of efficient catalysts with application–oriented active sites/species.
催化剂效率高、制备方便、稳定性好,在加氢反应中具有巨大的应用潜力。在这项工作中,地球丰富的铜锚定在硼和氮共掺杂碳催化剂(Cu@BNC)上,通过简单的一锅煅烧方法构建。通过改变煅烧温度,可以很容易地控制从单原子、团簇到纳米颗粒的Cu物质的大小。合成的Cu@BNC催化剂具有比表面积大、Cu活性位点高度分散、界面性质可调等优点。以硝基芳烃加氢还原为例,Cu@BNC催化剂的催化性能不仅取决于Cu的种类大小,还取决于BNC的支持作用,如合适的表面电荷,以及金属-载体界面上的临界Cuδ+ -Nx结构。因此,构建的含有Cu单原子和少量簇的Cu@BNC -900催化剂在4 -硝基苯酚还原中表现出了0.378 min−1的异常速率常数和0.80 min−1的周转频率(甚至优于含有大多数单原子的催化剂),并且具有良好的可回收性和稳定性。这一工作为合理设计具有应用活性位点/种类的高效催化剂提供了思路。
Image-based finite element modelling of fibre dynamics in polyester staple spun yarns
Haoqi Zhang, Abdul Jabbar, Aonan Li, Xinxin Wang, Dongmin Yang, Muhammad Tausif
doi:10.1016/j.compscitech.2025.111036
基于图像的涤纶短纺纱纤维动力学有限元建模
This paper introduces an innovative finite element (FE) modelling approach for fibre dynamics in a staple spun yarn based on the geometrical model derived from X-ray microcomputed tomography (μCT) images. The FE model retains crucial in situ information on fibre anisotropy, length, and continuity while employing advanced stitched scanning technique to reconstruct a 15mm yarn length containing individual fibres with ∼10μm diameter. The research focuses on 100% polyethylene terephthalate (PET) staple ring-spun yarn as a case study, conducting both single fibre and yarn tensile tests to characterise material properties and validate the FE model, respectively. Beyond examining the mechanical response at the yarn level, the model facilitates the investigation of individual fibre’s tensile stress, frictional forces, and extent of migration, thereby enhancing the understanding of fibre interactions during yarn tensile loading. Furthermore, the model enables parametric studies through manipulation of inter-fibre friction coefficients allowing assessment of their impact on overall mechanical behaviour. This innovative modelling approach demonstrates significant potential for exploring the constitutive and failure mechanisms for formation of microplastics from textiles and textile materials in general as well as fibre-reinforced composites. It addresses the critical research gaps in simulating anisotropic behaviours of materials containing textile fibres, paving the way for advanced material design and analysis in materials science and engineering.
本文介绍了一种基于x射线微计算机断层扫描(μCT)图像的几何模型的短纺纱纤维动力学有限元建模方法。FE模型保留了纤维各向异性、长度和连续性的关键原位信息,同时采用先进的缝合扫描技术重建了15mm纱线长度,其中包含直径为~ 10μm的单个纤维。该研究以100%聚对苯二甲酸乙二醇酯(PET)短纤维环纺纱为例,分别进行了单纤维和纱线拉伸测试,以表征材料性能并验证有限元模型。除了检查纱线水平的机械响应外,该模型还有助于研究单个纤维的拉伸应力、摩擦力和迁移程度,从而增强对纱线拉伸加载过程中纤维相互作用的理解。此外,该模型可以通过操纵纤维间摩擦系数进行参数化研究,从而评估其对整体机械行为的影响。这种创新的建模方法为探索纺织品和纺织材料以及纤维增强复合材料形成微塑料的本构和失效机制展示了巨大的潜力。它解决了在模拟含纺织纤维材料的各向异性行为方面的关键研究空白,为材料科学与工程中的先进材料设计和分析铺平了道路。