今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 4 篇,Composites Science and Technology 1 篇
Mechanical Performance of 3D Woven Glass Fiber I-beam Composites with In-situ Polyurethane Foaming
Kucukkalfa E, Isikci G, Yildiz K, Cebeci H
doi:10.1016/j.compstruct.2023.117636
原位聚氨酯发泡三维玻璃纤维编织工字钢复合材料的力学性能
3D weaving of I-beam structures can potentially create delamination- and joint-free structures, expanding their use in engineering applications compared to metal or traditional laminated composite beams. In addition, polymeric foams can be utilized to fill the vacancies between the web and the flanges of I beams, improving the mechanical characteristics and the structural integrity with little to no weight penalty. Moreover, interposing an adhesive layer between the I beam and the foam structure can result in a more effective bonding which intensifies the structure's robustness. In this study, high-performance I-beam composites were produced by combining polymeric foams with 3D woven glass fiber composites. Low- and high-density polyurethane foams were successfully inserted between the web and the flanges of 3D woven glass fiber composites manufactured by the vacuum infusion process using the free-rise foaming method. Samples with adhesive films were also produced to assess and compare their effectiveness with the composites made solely of polyurethane foam and I beam. The increases in energy absorption capacity and compressive and flexural properties were analyzed under compressive and flexural (three-point bending) loading. The obtained results indicate that structural integrity under bending can be substantially improved with the in-situ foaming supported by adhesive layers.
与金属或传统的层压复合梁相比,工字梁结构的三维编织有可能创造出无分层和无接缝的结构,从而扩大其在工程应用中的使用范围。此外,还可以利用聚合泡沫来填补工字梁腹板和翼板之间的空隙,从而在几乎不增加重量的情况下改善机械特性和结构完整性。此外,在工字梁和泡沫结构之间添加粘合剂层可以实现更有效的粘合,从而增强结构的坚固性。在这项研究中,通过将聚合物泡沫与三维玻璃纤维编织复合材料相结合,生产出了高性能工字梁复合材料。低密度和高密度聚氨酯泡沫被成功地插入了三维玻璃纤维编织复合材料的腹板和法兰之间。此外,还制作了带有粘合薄膜的样品,以评估和比较其与仅由聚氨酯泡沫和工字梁制成的复合材料的效果。在抗压和抗弯(三点弯曲)加载条件下,分析了能量吸收能力、抗压和抗弯特性的提高情况。结果表明,在粘合剂层的支持下,原位发泡可显著改善弯曲下的结构完整性。
Mechanical characteristics of reclaimed carbon fibre under superheated steam atmosphere and its feasibility for remanufacturing CFRP/CFRTP
Obunai K., Okubo K.
doi:10.1016/j.compositesa.2023.107843
过热蒸汽环境下再生碳纤维的机械特性及其再制造 CFRP/CFRTP 的可行性
This study is performed to investigate the effect of using superheated steam (SHS) in pyrolysis reclamation on the mechanical properties of reclaimed carbon fibres. The mechanical characteristics of the reclaimed fibres are evaluated by analyzing their tensile strength and fracture toughness. The feasibility of the reclaimed fibres is assessed by using them to remanufacture composites with epoxy and polypropylene matrices. The performance of the remanufactured composites is evaluated via mechanical testing. The test results show that using SHS in pyrolysis effectively prevents the degradation of the reclaimed carbon fibres. Variations in the tensile strength and fracture toughness of the reclaimed fibres are lower when pyrolysis is performed under a SHS atmosphere. Moreover, the mechanical characteristics of the remanufactured composites show that using SHS during pyrolysis reduces the degradation of the bending strength and Izod impact strength.
本研究旨在探讨在热解再生过程中使用过热蒸汽(SHS)对再生碳纤维机械性能的影响。通过分析再生纤维的拉伸强度和断裂韧性,对其机械特性进行了评估。通过使用再生纤维重新制造以环氧树脂和聚丙烯为基材的复合材料,评估了再生纤维的可行性。通过机械测试评估了再制造复合材料的性能。测试结果表明,在热解过程中使用 SHS 可以有效防止再生碳纤维的降解。在 SHS 气氛下进行热解时,再生纤维的拉伸强度和断裂韧性变化较小。此外,再生复合材料的机械特性表明,在热解过程中使用 SHS 可减少弯曲强度和伊佐德冲击强度的退化。
Molecular engineering of N-rich ZIF-integrated graphene composite interface for efficient physiochemical confinement and catalytic conversion of polysulfides in lithium–sulfur batteries
Chae Seongwook, Kim Sehun, Lee Taewoong, Kang Haisu, Kwon Young Je, Choi Gyeong Min, Heo Woo Sub, Park Jae Bin, Kim Ji-Oh, Kwon Taekyun, Kim Byeong Jin, Cho Chae-Ryong, Park Jun-Woo, Lee Seung Geol, Cho Kie Yong, Lee Jin Hong
doi:10.1016/j.compositesb.2023.111050
富含 N 的 ZIF 集成石墨烯复合界面的分子工程,用于锂硫电池中多硫化物的高效理化约束和催化转化
Lithium–sulfur (Li–S) batteries are regarded as one of the most promising energy storage systems because of their high theoretical specific capacity, energy density, low cost, and environmental benignancy. However, the practical application of Li–S batteries has been hindered by inevitable polysulfides shuttling behavior, the sluggish redox kinetics, and poor electrical conductivity of sulfur, which lead to rapid capacity decay and low active material utilization. In this study, we report a multifunctional layer consisting of N-rich zeolitic imidazolate frameworks (ZIF)/reduced graphene oxide (rGO) composite (NZG) as an electrocatalyst to overcome the drawbacks of Li–S batteries. During the preparation of NZG, deamination of the ZIF8A induces the incorporation of abundant N-containing moieties into rGO (pyridinic and pyrrolic N), which results in providing favorable active sites for polysulfides confinement and their rapid conversion via physiochemical interactions. Additionally, hierarchical pores with large surface area and interconnected conductive pathways in the as-prepared multifunctional layer accelerate the catalytic conversion kinetics of polysulfide species, leading to high sulfur utilization and enhanced Li–S battery electrochemical performance. This work suggests an efficient approach for designing multifunctional layers to achieve high-performance Li–S batteries.
锂硫(Li-S)电池因其理论比容量高、能量密度大、成本低和对环境无害而被视为最有前途的储能系统之一。然而,由于多硫化物不可避免的穿梭行为、缓慢的氧化还原动力学和硫的不良导电性,导致容量快速衰减和活性材料利用率低,锂-硫电池的实际应用一直受到阻碍。在本研究中,我们报告了一种富含 N 的沸石咪唑酸框架(ZIF)/还原氧化石墨烯(rGO)复合材料(NZG)组成的多功能层,作为电催化剂克服了锂-S 电池的缺点。在制备 NZG 的过程中,ZIF8A 的脱氨基作用诱导了大量含 N 的分子(吡啶 N 和吡咯 N)加入到 rGO 中,从而为多硫化物提供了有利的活性位点,并通过生化作用使其快速转化。此外,制备的多功能层中具有大表面积的分层孔隙和相互连接的导电通路可加速多硫化物的催化转化动力学,从而提高硫的利用率并增强锂-S 电池的电化学性能。这项工作为设计多功能层以实现高性能锂-S 电池提出了一种有效的方法。
Metal matrix composite with superior ductility at 800 °C: 3D printed In718+ZrB2 by laser powder bed fusion
Tekoğlu Emre, O'Brien Alexander D., Bae Jong-Soo, Lim Kwang-Hyeok, Liu Jian, Kavak Sina, Zhang Yong, Kim So Yeon, Ağaoğulları Duygu, Chen Wen, Hart A. John, Sim Gi-Dong, Li Ju
doi:10.1016/j.compositesb.2023.111052
金属基复合材料在 800 °C 时具有优异的延展性:通过激光粉末床熔融技术三维打印 In718+ZrB2
We investigated the microstructural and mechanical properties of ZrB2 fortified Inconel 718 (In718+ZrB2) superalloy metal matrix composite (MMC), which was produced via Laser Powder Bed Fusion (LPBF). 2 vol% ZrB2 nano powders (below 100 nm in diameter) were decorated on the surfaces of Inconel 718 alloy powders by high-speed blender. Microstructural analysis of the as-printed specimens showed that the ZrB2 decomposed during LPBF, which promoted the formation of homogeneously distributed (Zr, Ni)-based intermetallic and (Nb, Mo, Cr)-based boride nanoparticles in the matrix. The 3D printed In718+ZrB2 has remarkably lower porosity and smaller grain size compared to 3D printed In718 fabricated under the same LPBF conditions. The mechanical performance of the as-printed and heat-treated In718+ZrB2 showed significantly higher room temperature (RT) hardness, RT yield strength (σYS), and RT ultimate tensile strength (σUTS) compared to In718. High-temperature tensile tests at 800 °C showed that In718+ZrB2 has ∼10× tensile ductility with higher σYS (10 %) and σUTS (8 %) than pure In718.
我们研究了通过激光粉末床融合(LPBF)技术生产的 ZrB2 强化 Inconel 718(In718+ZrB2)超合金金属基复合材料(MMC)的微观结构和力学性能。通过高速搅拌机将 2 Vol% 的 ZrB2 纳米粉末(直径小于 100 nm)装饰在 Inconel 718 合金粉末的表面。打印试样的微观结构分析表明,ZrB2在LPBF过程中分解,促进了基体中均匀分布的(Zr、Ni)金属间化合物和(Nb、Mo、Cr)硼化物纳米颗粒的形成。与在相同 LPBF 条件下制造的三维打印 In718 相比,三维打印 In718+ZrB2 的孔隙率更低,晶粒尺寸更小。与 In718 相比,经过打印和热处理的 In718+ZrB2 的机械性能显示出更高的室温(RT)硬度、RT 屈服强度(σYS)和 RT 极限拉伸强度(σUTS)。800 °C 高温拉伸试验表明,与纯 In718 相比,In718+ZrB2 具有 ∼10 倍的拉伸延展性,σYS(10 %)和σUTS(8 %)也更高。
Elastic architected mechanical metamaterials with negative stiffness effect for high energy dissipation and low frequency vibration suppression
Chen Shuai, Liu Xin, Hu Jiqiang, Wang Bing, Li Menglei, Wang Lianchao, Zou Yajun, Wu Linzhi
doi:10.1016/j.compositesb.2023.111053
具有负刚度效应的弹性结构机械超材料,用于高能耗耗散和低频振动抑制
In this research, mechanical metamaterials with negative stiffness (NS) effect were architected and fabricated for high energy dissipation and low frequency vibration suppression. Periodic cellular metamaterials formed by connecting multiple NS elements in series exhibited hysteresis and lengthy sawtooth loading and unloading plateaus, which made them desirable for use in energy dissipation applications. And the key point was that the deformation of these metamaterials was completely reversible. To determine the underlying cause of hysteresis, the mechanical behavior with phase-transition characteristics was analyzed. Then, a finite element model was built, and the numerical simulation results were compared to the experimental test findings of the metamaterials, and the two were in good agreement, verifying the validity of the model. Furthermore, the influences of structural parameters on mechanical characteristics were systematically investigated and discussed utilizing the numerical models that had undergone experimental validation. The energy dissipation effect resulting from the phase transformation mechanisms could also be applied to the field of vibration control. Corresponding hammer tests were performed to explore the dynamic behavior of the NS metamaterials. The results show that the proposed metamaterials exhibit excellent vibration suppression performance, especially for low frequency vibration mitigation.
本研究设计并制造了具有负刚度(NS)效应的机械超材料,用于高能量耗散和低频振动抑制。通过将多个负刚度元件串联形成的周期性蜂窝超材料表现出滞后性和冗长的锯齿形加载和卸载高原,因此非常适合用于能量耗散应用。最关键的是,这些超材料的变形是完全可逆的。为了确定滞后的根本原因,我们分析了具有相变特性的机械行为。然后,建立了一个有限元模型,并将数值模拟结果与超材料的实验测试结果进行了比较,结果两者非常吻合,验证了模型的有效性。此外,利用经过实验验证的数值模型,系统地研究和讨论了结构参数对力学特性的影响。相变机制产生的能量耗散效应也可应用于振动控制领域。为探索 NS 超材料的动态行为,还进行了相应的锤击试验。结果表明,所提出的超材料具有出色的振动抑制性能,尤其是在低频振动缓解方面。
Fe-NC nanozymes-loaded TiO2 nanotube arrays endow titanium implants with excellent antioxidant capacity for inflammation inhibition and soft tissue integration
Zhu Hongqin, Zhang Haifeng, Chen Shuhan, Guan Shiwei, Lu Wei, Zhu Haihong, Ouyang Liping, Liu Xuanyong, Mei Yongfeng
doi:10.1016/j.compositesb.2023.111054
Fe-NC纳米酶负载的TiO2纳米管阵列赋予钛植入物卓越的抗氧化能力,可抑制炎症并与软组织融为一体
Titanium (Ti) and its alloys have been widely used as percutaneous and subcutaneous implants due to their excellent mechanical properties and biocompatibility. However, the aggregation of reactive oxygen species (ROS) and persistent inflammatory responses at the implant site severely affect the soft tissue integration of Ti implants, causing a series of biological complications. To address this issue, in this study, Fe-nitrogen-doped carbon single-atom nanozymes (Fe-NC nanozymes) loaded titanium oxide nanotube arrays (Fe-NC@TNT) were constructed by anodic oxidation and solvothermal method on medical titanium surfaces. The surface morphology, physical composition, enzyme-like catalytic activity, inflammatory response, and soft tissue compatibility of Fe-NC@TNT were investigated. The unique nanotube array fully exposes the catalytic active sites of Fe-NC nanozymes and significantly enhances their enzyme-like catalytic performance to eliminate superoxide anion, hydrogen peroxide, and more toxic hydroxyl radicals, which could effectively reduce the intracellular ROS levels of macrophages and fibroblasts, thereby inhibiting the inflammatory responses of macrophages and promoting the functional expression of fibroblasts. In vivo animal experiments have further demonstrated that Fe-NC@TNT can effectively regulate the immune response and promote the integration between the implant and the surrounding soft tissues.
钛(Ti)及其合金具有优异的机械性能和生物相容性,已被广泛用作经皮和皮下植入物。然而,活性氧(ROS)的聚集和植入部位持续的炎症反应严重影响了钛植入物的软组织整合,导致一系列生物并发症。针对这一问题,本研究采用阳极氧化和溶热法在医用钛表面构建了负载氧化钛纳米管阵列(Fe-NC@TNT)的铁氮掺杂碳单原子纳米酶(Fe-NC nanozymes)。研究了 Fe-NC@TNT 的表面形态、物理成分、酶样催化活性、炎症反应和软组织相容性。独特的纳米管阵列充分暴露了Fe-NC纳米酶的催化活性位点,显著增强了其酶促催化性能,可消除超氧阴离子、过氧化氢和毒性更强的羟自由基,有效降低巨噬细胞和成纤维细胞细胞内的ROS水平,从而抑制巨噬细胞的炎症反应,促进成纤维细胞的功能表达。体内动物实验进一步证明,Fe-NC@TNT 能有效调节免疫反应,促进植入物与周围软组织的融合。
High-temperature polymer dielectric films with excellent energy storage performance utilizing inorganic outerlayers
Liu Xue-Jie, Cheng Meng, Zhang Yiyi, Xing Yunqi, Dang Zhi-Min, Zha Jun-Wei
doi:10.1016/j.compscitech.2023.110305
利用无机外层实现具有优异储能性能的高温聚合物电介质薄膜
The optimization of high-temperature polymer capacitors is critical to the development of power electronics in harsh environments. The conduction loss of polymers increases dramatically at high temperatures, leading to a decrease in energy density and charge/discharge efficiency, which is a major impediment for capacitor applications. In this work, polyetherimide (PEI) composite films with trilayer structures are designed, in which the boron nitride nanosheet (BNNS) outer layers are optimized for charge blocking effect at multiple interfaces. The modulation of the inorganic layers not only increases the barrier height for charge injection from the electrodes, but also creates a PEI layer/BNNS layer interface that facilitates the formation of traps, thus effectively suppressing further carrier transport. Experiment and simulation verify that the construction of the trilayer structure promotes electric field redistribution, which significantly enhances high-temperature energy storage performance. At 200 °C, the energy density of the trilayer composite film is 3.81 J cm−3 with a charge/discharge efficiency >90 %, which is 766 % higher than PEI film (0.44 J cm−3 with a charge/discharge efficiency >90 %). Notably, the energy storage performance of trilayer composite film at high temperature is far superior to the reported high-temperature polymer dielectric films. This work demonstrates the promising potential of multilayer structures applied to dielectric polymer composite films at high temperatures.
高温聚合物电容器的优化对于在恶劣环境中开发电力电子产品至关重要。聚合物的传导损耗在高温下会急剧增加,从而导致能量密度和充放电效率下降,这是电容器应用的一大障碍。本研究设计了具有三层结构的聚醚酰亚胺(PEI)复合薄膜,其中优化了氮化硼纳米片(BNNS)外层,以在多个界面上实现电荷阻断效果。无机层的调制不仅增加了电荷从电极注入的阻挡高度,而且还形成了 PEI 层/BNNS 层界面,有利于陷阱的形成,从而有效地抑制了载流子的进一步传输。实验和模拟验证了三层结构的构建促进了电场再分布,从而显著提高了高温储能性能。200 °C 时,三层复合薄膜的能量密度为 3.81 J cm-3,充放电效率大于 90%,比 PEI 薄膜(0.44 J cm-3,充放电效率大于 90%)高 766%。值得注意的是,三层复合薄膜在高温下的储能性能远远优于已报道的高温聚合物电介质薄膜。这项工作证明了多层结构在高温下应用于聚合物介电复合薄膜的巨大潜力。