【新文速递】2024年7月1日复合材料SCI期刊最新文章

   

今日更新：Composite Structures 3 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 6 篇，Composites Science and Technology 4 篇

Composite Structures

Influences of cryo-thermal cycling on the tensile properties of short carbon fiber/polyetherimide composites

Zheng Sun, Quan-Xiu Liu, Feng Liu, Yuan-Qing Li, Fang-Liang Guo, Shao-Yun Fu

doi:10.1016/j.compstruct.2024.118336

低温热循环对短碳纤维/聚醚酰亚胺复合材料拉伸性能的影响

The reliability of short fiber reinforced polymer composites is crucial for their successful applications in aerospace engineering with cryo-thermal cycling (CTC). This study investigates the influences of on the tensile properties of short carbon fiber (SCF)/polyetherimide (PEI) composites at room temperature (25 °C) and elevated temperature (170 °C). First, SCF surfaces were coated by carbon nanotube-polydomaine (CNT-PDA) hybrid sizing, and then SCF/PEI composites were prepared via the facile injection molding technique. Impressively and unexpectedly, the tensile strength at 25 °C and 170 °C of SCF/PEI composites is all enhanced by the CTC exposure, attributing to the enhanced mechanical properties of PEI matrix and fiber/PEI interface. In addition, CNT-PDA sizing and CTC exposure have a combined effect on improving the tensile properties of SCF/PEI composites at 25 °C and 170 °C. Overall, the SCF/PEI composites exhibit excellent mechanical properties under extreme service conditions, and are thus promising to serve in aerospace components.

短纤维增强聚合物复合材料的可靠性是其在航空航天工程中成功应用低温热循环（CTC）的关键。本研究探讨了室温（25 °C）和高温（170 °C）下短碳纤维（SCF）/聚醚酰亚胺（PEI）复合材料拉伸性能的影响因素。首先在 SCF 表面涂覆碳纳米管-聚多巴胺（CNT-PDA）混合施胶，然后通过简便的注射成型技术制备 SCF/PEI 复合材料。令人印象深刻且出乎意料的是，SCF/PEI 复合材料在 25 ℃ 和 170 ℃ 下的拉伸强度均因四氯化碳暴露而增强，这归因于 PEI 基体和纤维/PEI 界面机械性能的增强。此外，CNT-PDA 施胶和四氯化碳暴露对改善 SCF/PEI 复合材料在 25 °C 和 170 °C 下的拉伸性能具有共同作用。总之，SCF/PEI 复合材料在极端使用条件下表现出优异的机械性能，因此有望用于航空航天部件。

Topology optimization framework for thermoelastic multiphase materials under vibration and stress constraints using extended solid isotropic material penalization

Minh-Ngoc Nguyen, Van-Nam Hoang, Dongkyu Lee

doi:10.1016/j.compstruct.2024.118316

在振动和应力约束条件下，利用扩展固态各向同性材料惩罚法优化热弹性多相材料拓扑框架

This paper proposes a multiphase material topology optimization (MMTO) method for thermal-mechanical structures that takes into account the effect of the temperature field under stress and frequency constraints. Thermoelastic coupling occurs when an engineering structure is concurrently subjected to thermal and mechanical loads. This work focuses on the following: (1) the derivation of three interpolation schemes that use stress, dynamic, and thermal loads based on the extended solid isotropic material penalization (SIMP) method; (2) the incorporation of stress and dynamic constraints of multi-material thermal-elastic structural designs; and (3) the effective control of the impact of thermal loads on structures based on stress and frequency levels. Numerical experiments show that a clear distinction exists in the final topologies for mechanical and thermal loads among materials. Coupled and uncoupled mechanical and thermal behaviors can be predicted using finite element models based on materials’ coefficients of thermal expansion. We see this method is capable of optimizing a structure’s strength and stability while solving the issue of a thermal environment. In addition, it allows for the precise management of stress and vibration levels when structures are not exposed to a thermal environment.

本文针对热机械结构提出了一种多相材料拓扑优化（MMTO）方法，该方法考虑了应力和频率约束下的温度场效应。当工程结构同时承受热负荷和机械负荷时，就会发生热弹性耦合。这项工作的重点如下：(1) 基于扩展的固体各向同性材料惩罚（SIMP）方法，推导出三种使用应力、动态和热载荷的插值方案；(2) 将应力和动态约束纳入多材料热弹性结构设计；以及 (3) 基于应力和频率水平，有效控制热载荷对结构的影响。数值实验表明，不同材料的机械载荷和热载荷的最终拓扑结构存在明显区别。利用基于材料热膨胀系数的有限元模型，可以预测耦合和非耦合机械和热行为。我们发现，这种方法在解决热环境问题的同时，还能优化结构的强度和稳定性。此外，当结构不暴露在热环境中时，它还能对应力和振动水平进行精确管理。

Low-Velocity Impact of carbon, flax, and hybrid composites: Performance comparison and numerical modeling

Giulia Del Bianco, Valentina Giammaria, Monica Capretti, Simonetta Boria, Stefano Lenci, Raffaele Ciardiello, Vincenzo Castorani

doi:10.1016/j.compstruct.2024.118318

碳、亚麻和混合复合材料的低速冲击：性能比较和数值建模

In recent years, composite materials have assumed an increasingly dominant role in various industrial sectors, combining lightweight with optimal mechanical properties. In this context, natural fibers are essential for the development of eco-friendly composites, ensuring a balance between performance and sustainability via hybridization. This study provides an experimental and numerical analysis on composite laminates subjected to Low-Velocity Impact (LVI) tests at different energy levels, after an initial mechanical characterization of the materials. Carbon and flax fiber fabrics are chosen as reinforcements embedded in a toughened epoxy resin, as well as in two hybrid configurations; two different stacking sequences are also investigated, with the layers placed at 0°and in a quasi-isotropic (ISO) orientation. Hysteresis curves and energy absorption capability – in terms of specific energy absorption (SEA) – are then discussed and compared to each other, along with cross-shaped damage propagation on fracture surfaces. Numerical finite element (FE) models of tensile, compressive, and LVI tests are designed and solved using LS-DYNA software. In particular, tensile and compressive ones are carried out to calibrate the material cards, which have subsequently been adopted in the LVI models. The results obtained not only show an agreement between the experimental response and the simulated one, but also provide a complete investigation of different materials and orientations under LVI in view of future applications, highlighting the possibility of designing structural components to absorb energy in hybrid composites reinforced with natural fibers.

近年来，复合材料在各个工业领域发挥着越来越重要的作用，兼具轻质和最佳机械性能。在这种情况下，天然纤维对于开发生态友好型复合材料至关重要，它通过杂化确保了性能与可持续性之间的平衡。本研究对复合材料层压板进行了实验和数值分析，在对材料进行初步机械特性分析后，对其进行了不同能量水平的低速冲击（LVI）测试。研究人员选择了碳纤维和亚麻纤维织物作为增强材料，将其嵌入增韧环氧树脂以及两种混合配置中；同时还研究了两种不同的堆叠顺序，即层叠方向为 0°和准各向同性（ISO）。然后讨论了滞后曲线和能量吸收能力（以比能量吸收（SEA）为单位），并将其与断裂面上的十字形损伤传播进行了比较。使用 LS-DYNA 软件设计并求解了拉伸、压缩和 LVI 试验的数值有限元 (FE) 模型。其中，拉伸和压缩试验是为了校准材料卡，这些材料卡随后被采用到 LVI 模型中。所获得的结果不仅显示了实验响应与模拟响应之间的一致性，而且从未来应用的角度出发，对 LVI 条件下的不同材料和取向进行了全面的研究，突出了在天然纤维增强的混合复合材料中设计吸收能量的结构组件的可能性。

Composites Part A: Applied Science and Manufacturing

An improved YOLOv8 for fiber bundle segmentation in X-ray computed tomography images of 2.5D composites to build the finite element model

Sheng Zhang, Kaiyu Wang, Huajun Zhang, Tong Wang, Xiguang Gao, Yingdong Song, Fang Wang

doi:10.1016/j.compositesa.2024.108337

改进 YOLOv8，用于在 2.5D 复合材料的 X 射线计算机断层扫描图像中分割纤维束，以建立有限元模型

It is necessary to segment fiber bundles in the reconstruction of the mesoscopic model of ceramic matrix composites using XCT images. Existing methods have great subjectivity, poor recognition accuracy, and heavy workload. To solve this problem, an improved lightweight YOLOv8 was proposed, which is a deep learning approach. By adding Slim-neck and VanillaNet, the complexity of the model was greatly reduced. Additionally, by replacing the loss function of the model with the Wise-IoU loss function, the ability of feature extraction of the model was improved. The effectiveness of the improved YOLOv8 in fiber bundle identification was demonstrated. Finally, a mesoscopic model was reconstructed by XCT images where fiber bundles were segmented by using the improved YOLOv8. The linear elastic modulus of the material was predicted and the error was found to be small, indicating that the improved YOLOv8 can effectively segment fiber bundles and thus reconstruct a high-precision mesoscopic model.

在使用 XCT 图像重建陶瓷基复合材料介观模型时，有必要对纤维束进行分割。现有方法主观性强、识别精度低、工作量大。为解决这一问题，提出了一种改进的轻量级 YOLOv8，这是一种深度学习方法。通过添加 Slim-neck 和 VanillaNet，大大降低了模型的复杂性。此外，通过用 Wise-IoU 损失函数替换模型的损失函数，提高了模型的特征提取能力。改进后的 YOLOv8 在纤维束识别中的有效性得到了验证。最后，通过 XCT 图像重建了介观模型，使用改进的 YOLOv8 对纤维束进行了分割。对材料的线性弹性模量进行了预测，发现误差很小，这表明改进型 YOLOv8 可以有效地分割纤维束，从而重建高精度的介观模型。

Composites Part B: Engineering

Molten Salt-assisted Synthesis of Cotton-like Dopamine-derived Carbon/Transition Metal Sulfide Composites with Effective Microwave Absorption

Zhiqian Yang, Zhijun Yu, Jie Li, Zhenqi Xu, Fan Wu

doi:10.1016/j.compositesb.2024.111666

熔盐辅助合成具有有效微波吸收能力的棉状多巴胺衍生碳/过渡金属硫化物复合材料

This report proposes a preparation route for the molten salt (MS)-assisted synthesis of cotton-like C/transition metal sulfide (TMD) composites. By using the mussel-inspired method, carbon derived from dopamine (DA) can be well combined with the TMDs synthesized by molten salt synthesis (MSS). The morphologies and structures, electromagnetic (EM) properties and MA performances were systematically analyzed. The results show that a series of synthesized cotton-like C/TMD composites exhibit efficient MA performance and are superior to many reports in the microwave absorption (MA) field. The best MA performance of cotton-like C/TMD composites can reach -63.49 dB, and the best effective absorption band (EAB) is 5.92 GHz. This work proposes a universal MS-assisted synthesis method for synthesizing composites with excellent MA performance and precise structure, which expands the application of MSS in the MA field and provides a reference for the synthesis of MA composites using the MS method combined with other methods.

本报告提出了一种熔盐（MS）辅助合成棉状碳/过渡金属硫化物（TMD）复合材料的制备路线。通过贻贝启发法，多巴胺（DA）衍生的碳可以与熔盐合成（MSS）的 TMD 很好地结合在一起。研究人员系统分析了其形态和结构、电磁（EM）特性以及 MA 性能。结果表明，一系列合成的棉状 C/TMD 复合材料表现出高效的 MA 性能，优于微波吸收（MA）领域的许多报道。棉状 C/TMD 复合材料的最佳 MA 性能可达 -63.49 dB，最佳有效吸收波段（EAB）为 5.92 GHz。本研究提出了一种通用的 MS 辅助合成方法，可合成出具有优异 MA 性能和精确结构的复合材料，拓展了 MSS 在 MA 领域的应用，为使用 MS 方法结合其他方法合成 MA 复合材料提供了参考。

Ultrastrong and ductile W-Cu composites via Al- mediated interfacial diffusion layers and matrix-nanoclusters networks

Peng-Cheng Cai, Guo-Hua Zhang, Kuo-Chih Chou

doi:10.1016/j.compositesb.2024.111667

 

通过铝介导的界面扩散层和基体-纳米团簇网络实现超强韧性的 W-Cu 复合材料

W-Cu composites are integrated materials with both structural and functional properties. However, the weak interfacial bonding capability leads to limited strain hardening, which makes it difficult to take full advantage of the coordination of the biphasic materials. In present work, a multistage strain-hardening (MSH) effect is created, which enables the W-Cu composites to possess a persistent and effective strain-hardening capability. The prepared W-30(CuAl5) (wt.%) alloy with significant tensile ductility (∼21%) and ultra-high yield strength (∼840 MPa). Remarkably, compared to the original W-30Cu without Al alloying, the strength and ductility are over two and three times, respectively, accompanied by the preservation of an electrical conductivity of about 80%. This excellent synergistic effect stems from the Al-mediated interpenetrating interfacial diffusion layers and matrix-nanoclusters interconnection networks. As a result, a high-density of dislocation segments, self-locking structures, and a variety of twinning mechanisms such as nanotwins and 9R configurations are sequentially activated, allowing the composites to accommodate ductility deformation while simultaneously facilitating interactions that produce three unusual rises in strain-hardening rate. The present work offers a critical perspective on the realization of a synergistic ultrahigh tensile ductility and strength combination in metal matrix composites.

W-Cu 复合材料是一种具有结构和功能特性的集成材料。然而，由于界面结合能力较弱，导致应变硬化有限，难以充分发挥双相材料的配位优势。本研究利用多级应变硬化（MSH）效应，使 W-Cu 复合材料具有持久有效的应变硬化能力。所制备的 W-30(CuAl5)（重量百分比）合金具有显著的拉伸延展性（∼21%）和超高屈服强度（∼840 兆帕）。值得注意的是，与未添加铝合金的原始 W-30Cu 相比，其强度和延展性分别提高了两倍和三倍以上，同时还保持了约 80% 的导电率。这种出色的协同效应源于铝介导的相互渗透的界面扩散层和基体-纳米团簇互连网络。因此，高密度的位错段、自锁结构以及各种孪晶机制（如纳米孪晶和 9R 构型）相继被激活，使复合材料能够适应延展性变形，同时促进相互作用，产生三种不同寻常的应变硬化率。本研究为在金属基复合材料中实现超高拉伸延展性和强度的协同组合提供了一个重要的视角。

Bi-layered polyurethane nanofiber patches with asymmetrical surface prevent postoperative adhesion and enhance cardiac repair

Shifen Li, Wajiha Ahmed, Shuqin Wang, Xinman Hu, Beiduo Wang, Zhaoyi Wang, Liyin Shen, Yang Zhu, Changyou Gao

doi:10.1016/j.compositesb.2024.111668

 

表面不对称的双层聚氨酯纳米纤维贴片可防止术后粘连并增强心脏修复效果

The adhesion between heart and chest post-operation raises a significant challenge for the application of cardiac patches due to its severe influences on the recovery of heart function and increased risk of re-treatment. Anabatic inflammatory response and increased oxidative stress aggravate the damage to heart functions. Herein, a multi-functional cardiac patch was manufactured by successive electrospinning of two types of novel selenium-containing polyurethanes (PU), followed by click grafting of poly(ethylene glycol) (PEG) molecules on the top layer. This patch possessed dual-functions of postoperative anti-adhesion and anti-oxidative stress for efficient therapy post myocardial infarction (MI). The high redox reactivity of diselenium bonds were introduced into the main chains of PU, which reduced the level of reactive oxygen species (ROS) and modulated the inflammatory environment, alleviating the synechia formation simultaneously. The cardiac patch could effectively resist fibroblast adhesion, regulate the expression of vinculin and tissue-type plasminogen activator (t-PA), and inhibit the synechia formation. Meanwhile, it also restored significantly the heart function post MI by decreasing the local inflammation, facilitating less collagen formation, and improving cell signal transduction and angiogenesis. Collectively, this novel patch achieved anti-adhesion and therapeutic effect synergistically, bringing advancement in cardiac patch design and potential for translation of medicinal devices.

手术后心脏和胸部之间的粘连对心脏功能的恢复有严重影响，并增加了再次治疗的风险，这给心脏贴片的应用带来了巨大挑战。无效的炎症反应和氧化应激的增加加重了对心脏功能的损害。本文通过对两种新型含硒聚氨酯（PU）进行连续电纺丝，然后在表层点击接枝聚乙二醇（PEG）分子，制造出了一种多功能心脏贴片。这种贴片具有术后抗粘连和抗氧化应激的双重功能，可有效治疗心肌梗塞（MI）后遗症。二硒键的高氧化还原反应性被引入聚氨酯主链，从而降低了活性氧（ROS）的水平，调节了炎症环境，同时缓解了裂隙的形成。心肌补片能有效抵抗成纤维细胞的粘附，调节长春新碱和组织型纤溶酶原激活剂（t-PA）的表达，抑制血栓形成。同时，它还能减少局部炎症，促进胶原蛋白的形成，改善细胞信号传导和血管生成，从而显著恢复心肌梗死后的心脏功能。总之，这种新型贴片实现了抗粘连和治疗效果的协同作用，推动了心脏贴片设计的进步，并有望转化为医疗设备。

Micromechanical and chemical characteristics of interfacial transition zone in alkali-activated slag concrete containing lightweight iron-rich aggregates

Shuqing Yang, Xiwen Guan, Jianxin Lu, Hongzhi Cui, Chi Sun Poon

doi:10.1016/j.compositesb.2024.111671

含有轻质富铁骨料的碱活性矿渣混凝土界面过渡区的微机械和化学特性

This study explored the time-varying alkali-activation effects of the lightweight aggregates (LWA) on the interfacial transition zone (ITZ) of the alkali-activated slag concrete with different curing ages, molar ratios, and alkali concentrations from 28 to 300 d. The improved micromechanical performance of the ITZ at 28 d stemmed from the early-age internal curing effect of the porous LWA. However, the post-28 d internal curing effect diminished, with the alkali-activation dominating the performance of the ITZ from 28 to 300 d. Although alkali-activated cement possessed early strength characteristics, the deconvolved phase results illustrated that alkali activation persisted in the ITZ between the LWA and cement from 28 to 300 d, leading to a high proportion of calcium silica aluminate hydrate. As a marker, Fe from the lightweight iron-rich aggregates mitigated into the alkali-activated cement, demonstrating the alkali-activated reaction between the LWA and alkali-activated slag matrix. Molecular dynamics simulations further characterized that the low content of Fe did not decrease the overall strength of the ITZ. The interfacial interaction energy revealed the alkali-activation between the LWA and cement compensated for the weakening of mechanical properties caused by Fe ions on the ITZ.

本研究探讨了轻质骨料（LWA）的碱活化效应对碱活化矿渣混凝土界面过渡区（ITZ）的时变影响。虽然碱活化水泥具有早期强度特性，但解卷积相结果表明，从 28 到 300 d，碱活化在 LWA 和水泥之间的 ITZ 中持续存在，导致水合硅铝酸钙比例较高。作为标记，轻质富铁聚集体中的铁减少到碱活化水泥中，这表明 LWA 和碱活化矿渣基质之间发生了碱活化反应。分子动力学模拟进一步表明，低含量的铁不会降低 ITZ 的整体强度。界面相互作用能表明，LWA 和水泥之间的碱激活作用弥补了 ITZ 上铁离子造成的力学性能减弱。

Transverse low-velocity impact behaviors of pultruded carbon-fiber-reinforced polymer rods with tensile preloads: Experiment and simulation

Zhen Wang, Rui Guo, Puxuan Zhang, Jiajun Shi, Chenggao Li, Bin Hong, Guijun Xian

doi:10.1016/j.compositesb.2024.111672

具有拉伸预紧力的拉挤碳纤维增强聚合物棒的横向低速冲击行为：实验与模拟

Extensive research has been conducted on the replacement of steel cables with carbon-fiber-reinforced polymer (CFRP) cables to eliminate steel corrosion and self-weight problems in cable-supported bridges. The potential low-velocity impact (e.g., vehicle collision) may cause CFRP cables to experience catastrophic failure. However, little attention has been paid to the low-velocity impact on a pultruded composite rod. This article focused on understanding and modeling the transverse impact behaviors of the pultruded CFRP rod with tensile preloads (0-0.58 preload ratios). Two damage models were proposed for predicting these behaviors: one combining the fiber/matrix damage model with a cohesive zone model (Model A), and the other employing only the fiber/matrix damage model (Model B). The short-beam shear test method was proposed to identify the intended interlaminar debonding location when employing a cohesive zone model. Both proposed models were validated against the experimental results, and their applicability was given. It was found that the tensile preloading presented a ‘stiffening effect’ and changed the rod from shear stress-dominated failure to tensile stress-dominated failure.

为消除缆索支撑桥梁中的钢腐蚀和自重问题，人们对用碳纤维增强聚合物（CFRP）缆索替代钢缆进行了广泛的研究。潜在的低速冲击（如车辆碰撞）可能会导致 CFRP 拉索出现灾难性故障。然而，人们很少关注拉挤复合材料杆受到的低速冲击。本文重点了解拉挤 CFRP 拉杆在拉伸预载（0-0.58 预载比）情况下的横向冲击行为，并对其进行建模。为预测这些行为提出了两种损伤模型：一种是纤维/基体损伤模型与内聚区模型相结合的模型（模型 A），另一种是仅采用纤维/基体损伤模型的模型（模型 B）。在采用内聚区模型时，建议采用短梁剪切试验方法来确定预定的层间脱粘位置。根据实验结果对这两个模型进行了验证，并给出了它们的适用性。结果发现，拉伸预加载产生了 "加固效应"，使杆件从以剪应力为主的破坏变为以拉伸应力为主的破坏。

Constructing layered/tunnel interlocking oxide cathodes for sodium-ion batteries based on breaking Mn3+/Mn4+ equilibrium in Na0.44MnO2 via trace Mo doping

Jingqiang Wang, Qing-Qun Sun, Jing Yu, Jun-Xu Guo, Ning-Ke Mo, Hong-Wei Li, Yu Su, Shiqiang Zhao, Yan-Fang Zhu, Haibin Chu, Shixue Dou, Yao Xiao

doi:10.1016/j.compositesb.2024.111664

 

通过掺杂痕量钼打破 Na0.44MnO2 中的 Mn3+/Mn4+ 平衡，为钠离子电池构建层状/隧道式互锁氧化物阴极

Sodium-ion batteries (SIBs) with Mn-based oxide cathodes have attracted much interest because of their cost effectiveness, minimal toxicity, and remarkable electrochemical activity. The typical tunnel Na0.44MnO2 cathode for SIBs exhibits stable cycling performance, but its low sodium content hinders the practical application. And the other NaxMnO2 with layered structures provide higher capacity but less satisfactory cycling. Therefore, it is of great significance to construct Mn-based oxide cathodes to integrate high specific capacity layered structure and high stability tunnel structure. Herein, the strategy of breaking the Mn3+/Mn4+ equilibrium in Na0.44MnO2 via doping trace amounts of Mo was proposed to promote the transformation from the original tunnel to the layered structure and to in-situ construct a layered/tunnel biphasic interlocking structure. The optimized interlocking layered/tunnel Na0.44Mn0.97Mo0.03O2 (NMO-3M) cathode integrates the advantages of layered and tunnel structures, and achieves highly reversible phase transition and excellent electrochemical performance, which delivers a high specific capacity of 178.9 mAh g-1 at 0.1 C and capacity retention of 77.8 % after 100 cycles at 1 C. The well-maintained P2 phase was revealed by the in-situ X-ray diffraction (XRD), demonstrating the highly reversible charge compensation and structural evolution. In addition, Na0.44Mn0.97Mo0.03O2 (NMO-3M) cathode shows a good storage performance in air over 270 days. This research designed a layered/tunnel interlocking structure induced by trace Mo doping to construct a stable and high capacity oxide cathode, providing a reference for the preparation of excellent oxide cathodes for SIBs in the future.

采用锰基氧化物阴极的钠离子电池（SIB）因其成本效益高、毒性小、电化学活性显著而备受关注。用于 SIB 的典型隧道式 Na0.44MnO2 阴极具有稳定的循环性能，但其钠含量较低，阻碍了其实际应用。而其他具有层状结构的 NaxMnO2 可提供更高的容量，但循环性能却不尽如人意。因此，构建集高比容量分层结构和高稳定性隧道结构于一体的锰基氧化物阴极具有重要意义。本文提出了通过掺杂微量钼打破 Na0.44MnO2 中 Mn3+/Mn4+ 平衡的策略，以促进原始隧道结构向层状结构的转变，并在原位构建层状/隧道双相交错结构。优化后的交错层状/隧道状 Na0.44Mn0.97Mo0.03O2 (NMO-3M) 阴极综合了层状结构和隧道状结构的优点，实现了高度可逆的相变和优异的电化学性能，在 0.5 mAh g-1 条件下的比容量高达 178.原位 X 射线衍射 (XRD) 显示，P2 相保持良好，证明了电荷补偿和结构演化的高度可逆性。此外，Na0.44Mn0.97Mo0.03O2（NMO-3M）阴极在空气中储存 270 天后显示出良好的储存性能。该研究设计了一种微量掺杂钼诱导的层状/隧道交错结构，构建了一种稳定的高容量氧化物阴极，为今后制备用于 SIB 的优良氧化物阴极提供了参考。

Composites Science and Technology

Statistical Modeling of 3D Fiber Geometry in Pultruded GFRP Composite: A Multi-Scale Approach

Jiapeng He, Fangcheng Zheng, Wenqiang Ma, Guowei Zhou, Guohua Fan, Zhangxing Chen, Zhanli Liu, Dayong Li

doi:10.1016/j.compscitech.2024.110734

 

拉挤 GFRP 复合材料中三维纤维几何形状的统计建模：多尺度方法

The fiber geometry is a crucial determinant of the fiber reinforced polymer composites’ mechanical properties. Specifically, the manufacturing process of stretching and gradual curving in pultruded composites invariably results in complex 3D fiber geometries. Despite its significance, there is still lacking a statistical method to accurately describe these spatially curved fiber shapes. This paper presents a novel multi-scale mathematical approach for modeling the complex 3D fiber geometry in pultruded glass fiber reinforced polymer (GFRP) composites, which includes the analysis of fiber misalignment and waviness at two scales. At the mesoscopic level, a modified elliptical symmetry angular Gaussian (ESAG) model effectively characterizes the fiber misalignment. Simultaneously, at the micro scale, a cosine series representation is employed for capturing local fiber waviness. The approach is verified with XCT scanning results of pultruded GFRP specimens. The current statistical modeling method provides a multi-scale approach for geometry analysis and further simulation of pultruded composite materials.

纤维的几何形状是决定纤维增强聚合物复合材料机械性能的关键因素。具体来说，拉挤复合材料的拉伸和逐渐弯曲的制造过程必然会产生复杂的三维纤维几何形状。尽管其意义重大，但目前仍缺乏一种统计方法来准确描述这些空间弯曲的纤维形状。本文提出了一种新颖的多尺度数学方法，用于模拟拉挤玻璃纤维增强聚合物（GFRP）复合材料中复杂的三维纤维几何形状，其中包括在两个尺度上对纤维错位和波状进行分析。在中观层面，改进的椭圆对称角高斯（ESAG）模型有效地描述了纤维错位的特征。同时，在微观尺度上，采用余弦级数表示法捕捉局部纤维波浪度。拉挤 GFRP 试样的 XCT 扫描结果验证了这一方法。当前的统计建模方法为拉挤复合材料的几何分析和进一步模拟提供了一种多尺度方法。

Absorption-diffusion integrated stacked metamaterials by multi-compound strategy for broadband electromagnetic attenuation

Yupeng Shi, Yuping Duan, Lingxi Huang, Wei Chen, Jiangyong Liu, Meng Wang, Chenyang Xia

doi:10.1016/j.compscitech.2024.110735

 

采用多复合策略的吸收-扩散集成堆叠超材料用于宽带电磁衰减

The meta-structural design of flat absorbers demonstrates significant potential for improving microwave attenuation performance. However, the single mechanism of amplitude attenuation through resonance-enhanced effect necessitates considerable material thickness, restricting its application in electromagnetic (EM) defense. Utilizing the synergistic effect of multiple mechanisms is expected to break through the performance limits of microwave stealth metamaterials at the sub-wavelength scale. Herein, absorption-diffusion integration stacked metamaterials (ADISM) were designed using a multi-compound strategy, which comprises bionic porous spherical carbonyl iron powder (SCIP) coatings and stacked vortex metasurfaces (VMs). Such a metamaterial integrates EM scattering modulation with microwave absorption, enabling the creation of a broadband, high-efficiency, low-reflection design, providing an effective absorption bandwidth (EAB) reaching 10.42 GHz (7.58-18 GHz) at a thickness of 2.48 mm. Manipulating the orbital angular momentum (OAM) to effect wavefront transformation, the dissipation of EM wave energy is achieved. The absorption peak frequency modulation and absorption bandwidth broadening are achieved by the intrinsic loss capability of the porous coating, and corresponding mechanisms are demonstrated by simulation models. In short, the synergistic effects of microwave absorption and scattering modulation significantly enhance the return loss capability and facilitate broadband microwave attenuation. This research offers new insights into the multifunctional integration of EM stealth metamaterials.

平面吸收器的元结构设计在提高微波衰减性能方面具有巨大潜力。然而，通过共振增强效应实现振幅衰减的单一机制需要相当大的材料厚度，限制了其在电磁（EM）防御中的应用。利用多种机制的协同效应有望突破微波隐身超材料在亚波长尺度上的性能极限。在此，我们采用多化合物策略设计了吸收扩散集成堆叠超材料（ADISM），其中包括仿生多孔球形羰基铁粉（SCIP）涂层和堆叠涡旋超表面（VMs）。这种超材料将电磁散射调制与微波吸收融为一体，实现了宽带、高效、低反射设计，在厚度为 2.48 毫米的情况下，有效吸收带宽（EAB）达到 10.42 千兆赫（7.58-18 千兆赫）。通过操纵轨道角动量（OAM）来实现波前变换，从而达到消散电磁波能量的目的。多孔涂层的固有损耗能力实现了吸收峰频率调制和吸收带宽拓宽，并通过模拟模型证明了相应的机制。总之，微波吸收和散射调制的协同效应显著提高了回波损耗能力，促进了宽带微波衰减。这项研究为电磁隐形超材料的多功能集成提供了新的见解。

Nacre-inspired flexible and thermally conductive phase change composites with parallelly aligned boron nitride nanosheets for advanced electronics thermal management

Zi-jie Huang, Rui-qing Wang, Wan-jun Jiang, Yu-long Liu, Ting-yu Zhu, De-xiang Sun, Jing-hui Yang, Xiao-dong Qi, Yong Wang

doi:10.1016/j.compscitech.2024.110736

 

采用平行排列的氮化硼纳米片的纳克启发柔性导热相变复合材料，用于先进电子设备的热管理

Phase change materials (PCMs) are widely applied in passive thermal management and energy storage fields because of their large latent heat capability near phase transition points. However, molten leakage, inherent rigidity, and low thermal conductivity limit the thermal management applications of PCMs. In this work, a scalable doctor-blading technique was developed to prepare anti-leakage, flexible, and highly thermally conductive PCM composites. Paraffin wax (PW) works as the thermal energy storage unit, polydimethylsiloxane (PDMS) encapsulates the molten PW and imparts the composites with flexibility, and 1-Butyl-3-methylimidazolium Hexafluorophosphate (BMIMPF6)-modified boron nitride nanosheets (BPs) ensure high thermal conductivity. BPs were firstly achieved from bulk boron nitride (BN) powders and BMIMPF6 ionic liquid (IL) by the one-step ball milling process, then high-oriented alignment of BPs in PDMS/PW matrix was obtained by the strong shearing forces along the blade-casting direction. Owing to the high quality of BPs and interconnected structure of BPs network, the composites possessed high in-plane thermal conductivity of 2.87 W·m-1·K-1 at 15 wt% BPs, exhibiting a remarkable enhancement of 1494% compared with PDMS/PW. The flexible composites showed effective heat dissipation performance by reducing the working temperature of smartphones over 11 °C. Finite element analysis demonstrated that the parallel alignment of BPs network and the thermal energy buffering of PW were crucial for improving the thermal management capability. Furthermore, the PDMS/PW/BP composites exhibited excellent flame-retardant and electrically insulating properties. This work provides a feasible method to prepare high-performance PCM composites, which show great application prospects in the thermal management of electronic devices.

相变材料（PCM）在相变点附近具有较大的潜热能力，因此被广泛应用于无源热管理和储能领域。然而，熔融泄漏、固有刚性和低热导率限制了 PCM 的热管理应用。本研究开发了一种可扩展的刮削技术，用于制备防泄漏、柔性和高导热性 PCM 复合材料。石蜡（PW）作为热能存储单元，聚二甲基硅氧烷（PDMS）封装熔融石蜡并赋予复合材料柔韧性，1-丁基-3-甲基咪唑六氟磷酸盐（BMIMPF6）修饰的氮化硼纳米片（BPs）确保了高热导率。氮化硼纳米片首先由块状氮化硼（BN）粉末和 BMIMPF6 离子液体（IL）通过一步球磨工艺制得，然后通过沿刀片铸造方向的强大剪切力在 PDMS/PW 基体中获得高取向排列的氮化硼纳米片。由于 BPs 的高质量和 BPs 网络的互连结构，复合材料在 15 wt% BPs 时具有 2.87 W-m-1-K-1 的高面内热导率，与 PDMS/PW 相比显著提高了 1494%。柔性复合材料具有有效的散热性能，可将智能手机的工作温度降低 11 ℃ 以上。有限元分析表明，BPs 网络的平行排列和 PW 的热能缓冲是提高热管理能力的关键。此外，PDMS/PW/BP 复合材料还具有优异的阻燃和电绝缘性能。这项工作为制备高性能 PCM 复合材料提供了一种可行的方法，在电子设备的热管理方面具有广阔的应用前景。

Reprocessable and Repairable Carbon Fiber Reinforced Vitrimer Composites Based on Thermoreversible Dynamic Covalent Bonding

Mei Fang, Xiang Liu, Yuezhan Feng, Ming Huang, Chuntai Liu, Changyu Shen

doi:10.1016/j.compscitech.2024.110731

 

基于热可逆动态共价键合的可再加工和可修复碳纤维增强型玻璃纤维复合材料

The emergence of vitrimers breaks through the limitation of traditional carbon fiber reinforced thermoset composites (CFRP) caused by their permanent crosslinking molecular networks. Herein, the dynamic cross-linked network of vitrimer was synthesized from Bisphenol A diglycidyl ether (DGEBA) and glutaric anhydride (GA) under the catalysis of zinc acetylacetonate (Zn(acac)2), and the corresponding carbon fiber reinforced vitrimer composites (CF/Vx) were prepared via an impregnation and hot pressing process. The dynamic covalent adaptable networks (CANs) of vitrimer endow CF/Vx with stress relaxation and creep characteristics. By adjusting the catalyst content, the dynamic performance of CF/V0.05 can be optimized to achieve the highest viscous flow activation energy (60 kJ/mol) and the lowest characteristic relaxation time (1.0×10-3 s). The unique dynamic properties enable CF/Vx with reprocessability at high temperature. Typically, the flexural modulus of CF/V0.05 decreased from 87 ± 1.81 GPa at room temperature to 4.62 ± 0.28 GPa at 220 oC, which confirms the feasibility of thermoplastic forming of CF/V0.05 at high temperatures. Based on this, a CF/V0.05-based cap-shaped component was successfully manufactured through a thermoforming process. Additionally, the CF/V0.05 composites also exhibit repairability for interlaminar fractures. The optimal CF/V0.05 can achieve a repair efficiency of 128% under the hot press conditions of 180 °C, 10 MPa and 1 h. Hence, the reprocessable and repairable CF/Vx composites hold enormous potential in the engineering field.

玻璃聚合物的出现突破了传统碳纤维增强热固性复合材料（CFRP）因其永久交联分子网络而造成的局限性。本文以双酚 A 二缩水甘油醚（DGEBA）和戊二酸酐（GA）为原料，在乙酰丙酮锌（Zn(acac)2）催化下合成了动态交联的玻璃聚合物网络，并通过浸渍和热压工艺制备了相应的碳纤维增强玻璃聚合物复合材料（CF/Vx）。玻璃纤维的动态共价适应网络（CAN）赋予了 CF/Vx 应力松弛和蠕变特性。通过调整催化剂含量，CF/V0.05 的动态性能可以得到优化，从而获得最高的粘流活化能（60 kJ/mol）和最低的特性松弛时间（1.0×10-3 s）。独特的动态特性使 CF/Vx 具有高温下的再加工性。通常，CF/V0.05 的弯曲模量从室温下的 87 ± 1.81 GPa 下降到 220 oC 时的 4.62 ± 0.28 GPa，这证实了 CF/V0.05 在高温下热塑性成型的可行性。在此基础上，通过热成型工艺成功制造出了基于 CF/V0.05 的帽形部件。此外，CF/V0.05 复合材料还表现出了层间断裂的可修复性。因此，可再加工和可修复的 CF/Vx 复合材料在工程领域具有巨大的潜力。