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今日更新:Composite Structures 2 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇
Bending performance and failure mechanisms of hybrid and regular sandwich composite structures with 3D printed corrugated cores
Shah S.Z.H., Altaf Khurram, Lee Juhyeong, Sharif T., Choudhry R.S., Hussain S.M.
doi:10.1016/j.compstruct.2023.117580
带有 3D 打印波纹芯材的混合和常规夹层复合材料结构的弯曲性能和失效机理
The effect of core geometry and hybridization on the bending performance and failure mechanisms of carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) corrugated sandwich composite structures (SCS) were experimentally investigated using a three-point bend test. The CFRP and GFRP corrugated cores and facesheets were produced using Fused Filament Fabrication (FFF) and vacuum-assisted infusion processes, respectively. Three types of corrugated SCSs were built: SCSs with different core geometries (circular, square, trapezoidal, sinusoidal, and triangular), hybrid SCSs with different CFRP and GFRP cores and facesheets, and fully 3D-printed CFRP and GFRP SCSs. The corrugated SCS with square core geometry outperformed due to the presence of vertical walls and a large bonding area. The hybrid SCSs with a CFRP core showed a significant load drop due to shear failure in the 3D-printed core caused by weak inter-layer bonding. In contrast, the hybrid SCS with a GFRP core deformed plastically and absorbed more energy without failure due to strong inter-layer bonding. In fully 3D printed SCSs, the GFRP specimen failed catastrophically due to higher bending stress at the bottom facesheet, while the CFRP undergoes plastic deformation without failure. Results elucidate that the hybrid corrugated SCS with a GFRP top facesheet and 3D-printed core is an appropriate configuration for superior bending performance. The proposed 3D-printed SCS enables optimising complex shapes and material distribution in the core, resulting in improved strength-weight ratios. These findings will make an important contribution to the design and development of fibre-reinforced 3D-printed SCS for lightweight and high-performance applications.
通过三点弯曲试验,实验研究了芯材几何形状和杂化对碳纤维增强聚合物(CFRP)和玻璃纤维增强聚合物(GFRP)波纹夹层复合材料结构(SCS)弯曲性能和破坏机制的影响。CFRP 和 GFRP 波纹芯材和面材分别采用熔融长丝制造(FFF)和真空辅助导流工艺制成。共制造了三种波纹 SCS:不同芯材几何形状(圆形、方形、梯形、正弦曲线形和三角形)的 SCS,不同 CFRP 和 GFRP 芯材和面材的混合 SCS,以及完全 3D 打印的 CFRP 和 GFRP SCS。具有方形芯材几何形状的波纹 SCS 由于存在垂直壁和较大的粘合面积而表现出色。带有 CFRP 内核的混合 SCS 由于层间粘结力弱,导致 3D 打印内核剪切失效,从而导致载荷大幅下降。相比之下,带有 GFRP 内核的混合 SCS 由于层间粘结力强,可产生塑性变形并吸收更多能量而不会失效。在完全三维打印的 SCS 中,GFRP 试样由于底部面板的弯曲应力较大而发生灾难性失效,而 CFRP 则发生塑性变形而没有失效。研究结果表明,具有 GFRP 顶部面板和 3D 打印芯材的混合波纹 SCS 是实现优异弯曲性能的合适配置。拟议的三维打印 SCS 能够优化芯材的复杂形状和材料分布,从而提高强度-重量比。这些发现将为设计和开发用于轻质和高性能应用的纤维增强 3D 打印 SCS 做出重要贡献。
A multi resonant wave-absorbing honeycomb sandwich structure with excellent electrical performance damage tolerance
Zhao Yiming, Xing Suli, Tang Nianhua, Wu Nan, Tang Jun, He Yonglyu, Yin Changping, Zhang Jianwei
doi:10.1016/j.compstruct.2023.117581
具有优异电气性能和耐损坏性的多谐振吸波蜂窝夹层结构
Wave-absorbing honeycomb sandwich structure (HSS) is widely used in aviation equipment, playing an important role in the integration of load-bearing and stealth shielding. The high-intensity service of aviation equipment beyond design condition accelerates damage and complicates failure triggers. In this work, a decentralized construction strategy with multiple resonant absorption peaks is proposed to enhance the electrical performance damage tolerance (EDT) of wave-absorbing HSS in 4-18 GHz frequency band. The designed multi resonant absorption peaks for 30 mm thick wave-absorbing honeycomb with 1 mm thick SiO2 fiber reinforced epoxy resin (SiO2f/ER) composites as top and bottom panels occur in the vicinity of 5 GHz, 9 GHz, 13 GHz, and 17 GHz, respectively. When the panel damage area accounts for 72% or the penetrating damage area accounts for 18%, the effective absorption bandwidth (EAB) of proposed HSS covers 4-18 GHz, indicating excellent EDT. By analyzing the normalized impedance, Smith chart, as well as power loss density, the excellent EDT is attributed to the pinning effect at each resonant frequency point, which benefits both impedance matching and electromagnetic wave (EMW) attenuation.
吸波蜂窝夹层结构(HSS)广泛应用于航空设备,在承重和隐身屏蔽一体化中发挥着重要作用。航空设备超出设计状态的高强度服役会加速损坏并使故障触发复杂化。本研究提出了一种具有多个谐振吸收峰的分散结构策略,以提高 4-18 GHz 频段吸波 HSS 的电气性能损伤容限(EDT)。对于 30 毫米厚的吸波蜂窝和 1 毫米厚的二氧化硅纤维增强环氧树脂(SiO2f/ER)复合材料作为顶部和底部面板,设计的多谐振吸收峰分别出现在 5 GHz、9 GHz、13 GHz 和 17 GHz 附近。当面板损伤面积占 72% 或穿透损伤面积占 18% 时,拟议 HSS 的有效吸收带宽(EAB)为 4-18 GHz,表明 EDT 性能优异。通过分析归一化阻抗、史密斯图和功率损耗密度,可将优异的 EDT 归因于每个谐振频率点的针 刺效应,这有利于阻抗匹配和电磁波(EMW)衰减。
Design and manufacture of a Type V composite pressure vessel using automated fibre placement
Air Alexander, Oromiehie Ebrahim, Prusty B. Gangadhara
doi:10.1016/j.compositesb.2023.111027
利用自动纤维放置技术设计和制造 V 型复合材料压力容器
Automated Fibre Placement (AFP) can improve composite pressure vessel design by enabling selective reinforcement and allowing a wider range of fibre orientations than the traditional filament winding process. This paper presents the development of an AFP Type V composite pressure vessel with a design working pressure of 4.22 MPa made using a novel collapsible mandrel. The design process is presented along with a thickness control strategy for the AFP parts using ply drops. The tank was manufactured, and the thickness was validated using 3D scanning. The mass of the AFP parts was also measured to within 2.23% of the predicted values. The finished tank was hydrostatically pressure tested to understand the leakage behaviour. Defects and difficulties encountered in this prototype are discussed and opportunities for future work and improvements have been identified.
与传统的长丝缠绕工艺相比,自动纤维铺放(AFP)工艺可以实现选择性加固并允许更多的纤维取向,从而改进复合材料压力容器的设计。本文介绍了使用新型可折叠心轴开发的 AFP V 型复合材料压力容器,其设计工作压力为 4.22 兆帕。本文介绍了设计过程,以及使用层降技术对 AFP 部件进行厚度控制的策略。水箱已制造完成,并通过 3D 扫描验证了厚度。此外,还测量了 AFP 部件的质量,结果与预测值相差 2.23%。完成后的水箱进行了静水压力测试,以了解其泄漏特性。对原型中遇到的缺陷和困难进行了讨论,并确定了未来工作和改进的机会。
Recent progress and strategic perspectives of high-voltage Na3V2(PO4)2F3 cathode: Fundamentals, modifications, and applications in sodium-ion batteries
Chen Yu-Hao, Zhao Yi-Han, Tian Shu-Hui, Wang Peng-Fei, Qiu Feilong, Yi Ting-Feng
doi:10.1016/j.compositesb.2023.111030
高压 Na3V2(PO4)2F3 阴极的最新进展和战略前景:钠离子电池的基础、改性和应用
The NASICON structure of Na3V2(PO4)2F3 (NVPF) separates the valence electrons between the polyanion group and V and regulates the redox coupling energy. As a result, NVPF exhibits a high operating voltage in sodium-ion batteries. However, NVPF cathode material has poor specific capacity and low-rate performance. It is necessary to improve the electrochemical performance by increasing the electronic conductivity and accelerating the ion diffusion rate. Through morphology control, more active sites and ion channels can be provided to enhance rate performance and cycle stability. However, there are few reviews on how to control the morphology of NVPF. Therefore, this paper starts with the factors affecting the morphology of NVPF. The effects of pH value, surfactant, and external additives on its morphology were systematically summarized. On this basis, reasonable strategies, including morphology design, preparation method, structure control, surface modification, and defect engineering, are summarized. This paper provides theoretical support for the development of high-voltage NVPF. It provides inspiration for creating NVPF cathode materials with high specific capacity and high cycle performance.
Na3V2(PO4)2F3(NVPF)的 NASICON 结构可分离多阴离子基团和 V 之间的价电子,并调节氧化还原耦合能。因此,NVPF 在钠离子电池中具有很高的工作电压。然而,NVPF 正极材料的比容量较低,速率性能也不高。有必要通过提高电子电导率和加快离子扩散速度来改善电化学性能。通过形态控制,可以提供更多的活性位点和离子通道,从而提高速率性能和循环稳定性。然而,关于如何控制 NVPF 形貌的综述却很少。因此,本文从影响 NVPF 形态的因素入手。系统地总结了 pH 值、表面活性剂和外部添加剂对其形态的影响。在此基础上,总结了包括形态设计、制备方法、结构控制、表面改性和缺陷工程在内的合理策略。本文为高压 NVPF 的开发提供了理论支持。它为创造具有高比容量和高循环性能的 NVPF 阴极材料提供了灵感。
Superhydrophobic and robust photothermal/electrothermal PVDF-a/CNT-s@PDMS membrane for crude oil removal and dye adsorption
Chen Shengye, Zhou Jiale, Li Kunquan, Chen Zhuohan, Li Xuanjun, Su Xiaojing, Ao Xiaojuan, Xie Huali, Chen Lu, Wu Xuting, Wu Wenjian
doi:10.1016/j.compscitech.2023.110267
用于去除原油和吸附染料的超疏水性和坚固的光热/电热 PVDF-a/CNT-s@PDMS 膜
Recently, the crude oil spill has brought inevitable harm to the global ecological environment. Due to the high-viscosity crude oil, it is wise to take advantage of the photothermal/electrothermal effects of the membrane to separate the crude oil from the water. However, the functional separation membrane always suffers from low photothermal/electrothermal effects and poor stability. Herein, the vinyl polyvinylidene fluoride/mercapto carbon nanotubes@vinyl-terminated polydimethylsiloxane (PVDF-a/CNT-s@PDMS) membrane with fast photothermal/electrothermal effects and organic absorption property was successfully prepared by electrospinning and multi-layer loading method. The prepared PVDF-a/CNT-s@PDMS membrane resisted a variety of liquids and had stable superhydrophobicity (WCA = 156°). Furthermore, the membrane maintained superhydrophobicity even suffer from water and milk under the applied voltage condition. After 100 wear resistance tests, the membrane maintained stable superhydrophobicity and the separation rate remained unchanged. The surface temperature of the membrane rapidly approached to the maximum temperature in 30 s, showing a rapid photothermal/electrothermal effects, and the average separation rate of crude oil was 1185 kg m−2 h−1·bar−1. Meanwhile, the membrane exhibited outstanding efficiency for separate immiscible oil-water mixtures. Importantly, the incorporation of the sulfhydryl group enhanced the special ability of the composite membrane to adsorb organic dyes from oil phase. Therefore, the PVDF-a/CNT-s@PDMS membrane has a wide range of potential application in the domain of oil-water separation.
最近,原油泄漏给全球生态环境带来了不可避免的危害。由于原油粘度高,利用膜的光热/电热效应将原油从水中分离出来是明智之举。然而,功能分离膜总是存在光热/电热效应低、稳定性差的问题。本文采用电纺丝和多层负载法成功制备了具有快速光热/电热效应和有机吸收特性的乙烯基聚偏氟乙烯/巯基碳纳米管@乙烯基封端聚二甲基硅氧烷(PVDF-a/CNT-s@PDMS)膜。所制备的 PVDF-a/CNT-s@PDMS 膜可抵抗多种液体,并具有稳定的超疏水性能(WCA = 156°)。此外,在施加电压的条件下,该膜即使受到水和牛奶的侵蚀也能保持超疏水性能。经过 100 次耐磨测试后,膜仍能保持稳定的超疏水性,分离率也保持不变。膜的表面温度在 30 秒内迅速接近最高温度,显示出快速的光热/电热效应,原油的平均分离率为 1185 kg m-2 h-1-bar-1 。同时,该膜在分离互不相溶的油水混合物方面表现出卓越的效率。重要的是,巯基的加入增强了复合膜从油相吸附有机染料的特殊能力。因此,PVDF-a/CNT-s@PDMS 膜在油水分离领域具有广泛的应用前景。