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【新文速递】2024年1月1日复合材料SCI期刊最新文章

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今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇

Composite Structures

Influence of compaction and curing in the Automated Fiber Placement Process on the mechanical performance of composite laminates

Sylvester Vogl, Ralf Knott, Silvano Sommacal, Paul Compston, Klaus Drechsler

doi:10.1016/j.compstruct.2023.117826

自动纤维铺放工艺中的压实和固化对复合材料层压板机械性能的影响

This paper investigates the effect of compaction and curing states on the mechanical properties and void content of AFP-manufactured laminates. For the mechanical characterization, tensile tests, 4-point-bending tests and interlaminar shear strength (ILSS) tests were applied. The internal structure was evaluated via micro CT. For the surface structure evaluation, an optical profilometer was used. The void content was determined via segmentation of the micro CT images. The paper is subdivided into the description of the applied materials and methods, the results and their discussion and a conclusion. The study showcases the potential of AFP-manufactured aerospace composites to attain high-quality results even without the need for an autoclave, making them well-suited for unmanned applications.

本文研究了压实和固化状态对 AFP 制造的层压板的机械性能和空隙率的影响。在机械性能表征方面,采用了拉伸试验、4 点弯曲试验和层间剪切强度(ILSS)试验。内部结构通过微型 CT 进行评估。表面结构评估则使用了光学轮廓仪。通过对微型 CT 图像进行分割,确定了空隙含量。本文分为应用材料和方法描述、结果及其讨论和结论。该研究展示了 AFP 制造的航空航天复合材料的潜力,即使无需高压灭菌也能获得高质量的结果,使其非常适合无人驾驶应用。


Enhanced prediction of transverse mechanical behavior of unidirectional fiber-reinforced composites using new spatial descriptors based on deep neural networks

Sun Won Kim, Jae Hyuk Lim, Seong Su Kim

doi:10.1016/j.compstruct.2023.117870

利用基于深度神经网络的新空间描述符增强单向纤维增强复合材料横向力学行为的预测能力

In this study, we developed a data-driven approach using a deep neural network (DNN) to predict the nonlinear stress-strain behavior of fiber-reinforced composites under transverse tensile loading. We explored the impact of different input features characterizing the composite microstructure on the prediction accuracy of the DNN model. Specifically, we introduced a spatial descriptor representing fiber arrangement and proposed new spatial descriptors based on fiber area to improve input feature quality. Incorporating widely-used spatial descriptors such as the second-order intensity function and radial distribution function improved the prediction performance compared to previous methods. Combining spatial descriptors for both fiber distribution and alignment further enhanced prediction accuracy. To address the limitations of conventional spatial descriptors, we developed new spatial descriptors using a continuous function. Our findings demonstrate the importance of selecting appropriate input features for improved DNN model performance, even with the same dataset. Moreover, the proposed fiber area-based spatial descriptors offer insights into the micromechanical behavior of composite materials.

在这项研究中,我们利用深度神经网络(DNN)开发了一种数据驱动方法,用于预测横向拉伸载荷下纤维增强复合材料的非线性应力应变行为。我们探索了表征复合材料微观结构的不同输入特征对 DNN 模型预测精度的影响。具体来说,我们引入了代表纤维排列的空间描述符,并提出了基于纤维面积的新空间描述符,以提高输入特征的质量。与之前的方法相比,结合二阶强度函数和径向分布函数等广泛使用的空间描述符提高了预测性能。结合纤维分布和排列的空间描述符进一步提高了预测精度。为了解决传统空间描述符的局限性,我们使用连续函数开发了新的空间描述符。我们的研究结果表明,即使使用相同的数据集,选择适当的输入特征对于提高 DNN 模型性能也非常重要。此外,所提出的基于纤维面积的空间描述符为复合材料的微观机械行为提供了见解。


Mechanical vibration absorber for flexural wave attenuation in multi-materials metastructure

Long Liu, Ji Wan Kim, Gil Ho Yoon, Bing Yi

doi:10.1016/j.compstruct.2023.117859

用于衰减多材料结构中挠曲波的机械减震器

Vibration isolation is a promise to suppress mechanical vibration from a host structure, similarly, a mechanical vibration absorber, a simple but effective device to attenuate flexural wave propagation, which has been implemented in civil and mechanical engineering. This paper presents a type of composite sandwich phononic crystal to attenuate the flexural wave propagation in a beam structure, which can effectively suppress mechanical vibration in a broad band gap by repetitively arranging phononic crystal. First, the elastic wave dispersion characteristic in a composite sandwich beam structure is derived, and a triangular shape phononic crystal for flexural wave attenuation by taking advantage of destructive interference is presented. Then two dimensional phononic crystals are designed by assembling four different unit-cells of metabeam. Finally, numerical experiments are conducted to verify the effectiveness of the proposed mechanical metamaterial absorbers to attenuate flexural wave propagation, the numerical results indicate that the proposed metamaterial is of good performance in mechanical vibration suppression, which can effectively mitigate structure vibration in low-frequency domain than the structure without phononic crystal and single layer metamaterial beam structure. It is the first attempt to design a mechanical metamaterial absorber with the mechanism of destructive interference with composite sandwich phononic crystal.

隔振是一种抑制来自主机结构的机械振动的承诺,同样,机械吸振器也是一种简单而有效的衰减挠性波传播的装置,在土木工程和机械工程中已经得到了应用。本文提出了一种用于衰减梁结构中挠曲波传播的复合夹层声子晶体,通过重复排列声子晶体,可有效抑制宽带隙中的机械振动。首先,推导了复合夹层梁结构中的弹性波色散特性,并提出了一种利用破坏性干涉来衰减挠曲波的三角形声子晶体。然后,通过组装四个不同的元梁单元,设计了二维声子晶体。最后,通过数值实验验证了所提出的机械超材料吸波材料对挠性波传播的衰减效果,数值实验结果表明,所提出的超材料在机械振动抑制方面具有良好的性能,与不含声子晶体的结构和单层超材料梁结构相比,能有效缓解结构在低频域的振动。这是首次尝试利用复合夹层声子晶体的破坏性干涉机制设计机械超材料吸波材料。


Composites Part A: Applied Science and Manufacturing

Spatial variability characterization and modelling of 2.5D woven SiO2f/SiO2 composites

Hongyue Wang, Bing Wang, Maoqing Fu, Guodong Fang, Songhe Meng

doi:10.1016/j.compositesa.2023.107997

 

2.5D SiO2f/SiO2 编织复合材料的空间变化特征和建模

2.5D woven SiO2f/SiO2 composites possess geometric variabilities across scales, such as the spatial fluctuations of fibers and yarns or the random distributions of defects and pores formed in the manufacturing process, which induces a complex stress and strain distribution in material testing. In this study, a multivariate cross-correlated non-Gaussian random field based on Vine Copula is proposed to characterize the spatial variability of mechanical properties. A database of material mechanical properties is acquired by stochastic representative volume element (SRVE) simulation results which contains realistic meso-geometry characteristics and spatially random voids. Based on this database, the cross- and auto-correlations of the mechanical properties are quantified by Vine Copula and non-Gaussian random field model. In a comparison of different numerical models and experimental results, the proposed method is verified, which shows great advantages in characterizing the spatial variability and big potential abilities in damage or reliability analysis.

2.5D SiO2f/SiO2 编织复合材料具有跨尺度的几何变异性,如纤维和纱线的空间波动或制造过程中形成的缺陷和孔隙的随机分布,从而在材料测试中引起复杂的应力和应变分布。本研究提出了一种基于 Vine Copula 的多元交叉相关非高斯随机场,用于描述力学性能的空间变异性。材料力学性能数据库由随机代表体积元素(SRVE)模拟结果获得,其中包含真实的中间几何特征和空间随机空隙。在该数据库的基础上,采用 Vine Copula 和非高斯随机场模型对力学性能的交叉和自相关性进行了量化。通过比较不同的数值模型和实验结果,验证了所提出的方法在表征空间变异性方面的巨大优势,以及在损伤或可靠性分析方面的巨大潜力。


Functionalizing chitosan-based film with highly sensitive fire response and commendable flame retardancy for intelligent fire-alarm system

Rongkai Wu, Yu Wang, Yunyirui Liu, Bihe Yuan

doi:10.1016/j.compositesa.2023.107999

 

将壳聚糖基薄膜功能化,使其具有高度灵敏的火灾反应和值得称赞的阻燃性能,用于智能火灾报警系统

Recently, the extensive use of combustible materials has amplified building fire damage, making it essential to incorporate fire-detection devices and flame-retardant materials in building. Herein, the chitosan/gelatin (CG) film and KH2PO4-modified CG (KCG) films were fabricated via an eco-friendly water evaporation method. Impressively, KCG films demonstrate swift response times: 0.5 s at 100 ℃ and 1.8 s under flame, facilitating prompt alarms during fire incidents. Compared to CG, KCG achieve a 70.4% and 46.2% reduction in peak heat release rate and total heat release respectively. They also offer flexibility, transparency, repeated fire-warning efficacy and superior char formation. With these properties, KCG hold promise for innovative building fire safety solutions like smart fire-alarm wallpaper. Besides, a tailored wireless-based fire-alarm system for KCG further decreases building fire damage. This work mitigates damages arising from building fires work, marking significant leap forward in the use of bio-based materials for fire prevention in architecture.

近年来,可燃材料的广泛使用加剧了建筑物的火灾损失,因此在建筑物中加入火灾探测装置和阻燃材料至关重要。本文采用环保的水蒸发法制作了壳聚糖/明胶(CG)薄膜和 KH2PO4 改性 CG(KCG)薄膜。令人印象深刻的是,KCG 薄膜的响应时间很快:在 100 ℃ 下为 0.5 秒,在火焰下为 1.8 秒,有助于在火灾事故中迅速报警。与 CG 相比,KCG 的峰值放热率和总放热率分别降低了 70.4% 和 46.2%。此外,KCG 还具有柔韧性、透明性、多次火灾预警效果和优异的炭化性能。凭借这些特性,KCG有望成为智能火警墙纸等创新型建筑消防安全解决方案的首选。此外,为 KCG 量身定制的基于无线的火灾报警系统还能进一步降低建筑火灾损失。这项工作减轻了建筑火灾造成的损失,标志着生物基材料在建筑防火领域的应用取得了重大飞跃。


Composites Part B: Engineering

The synergistic effect of greenhouse gas CO2 and silica fume on the properties of 3D printed mortar

Hao Lucen, Li Long, Zhang Shipeng, Zhang Huanghua, Xiao Jianzhuang, Poon Chi Sun

doi:10.1016/j.compositesb.2023.111188

温室气体二氧化碳和硅灰对 3D 打印砂浆性能的协同效应

To fulfil the requirements of pumpability and buildability, the rheological properties of mortar/concrete for 3D printing should follow much stricter requirements than traditional-cast mortar/concrete. This study proposed to use a secondary CO2 mixing technique coupled with the addition of silica fume (SF) to achieve in-situ rheology control of 3D printed mortar. The influences of CO2 mixing on the properties of the cast mortar and the 3D printed mortar prepared with SF were systematically studied. The pH, conductivity and ion concentration were tested to revel the essential chemical reactions and phase evolutions during CO2 mixing. It was found that the CO2 mixing effectively enhanced the early-age penetration resistance and yield stress of mortar incorporated with SF, and thus significantly improved the buildability of 3D printed mortar, while the maximum printing layer increased higher than 33 layers. Meanwhile, the mechanical properties of the SF-incorporated mortar were improved by this process. It was revealed that during the CO2 mixing process, the injected CO2 rapidly reacted with calcium ions to form CaCO3, which further reacted with C3A to form monocarboaluminate (Mc). The fast precipitation of calcium ions during CO2 mixing accelerated the hydration of C3A and C3S, contributing to the rapid development of strength at early ages and the improved performance of hardened mortar. The addition of SF in mortar greatly amplified the beneficial effect of CO2 mixing, which due to SF as nucleation sites promoted the formation of CaCO3 and Mc during CO2 mixing.

为了满足可泵性和可施工性的要求,3D 打印砂浆/混凝土的流变特性应遵循比传统浇注砂浆/混凝土更严格的要求。本研究建议采用二次二氧化碳混合技术,并添加硅灰(SF),以实现对 3D 打印砂浆的原位流变控制。该研究系统地研究了二氧化碳混合对浇注砂浆和用 SF 制备的 3D 打印砂浆性能的影响。测试了 pH 值、电导率和离子浓度,以揭示二氧化碳混合过程中的基本化学反应和相变。研究发现,CO2 混合能有效提高掺入 SF 的砂浆的早龄期抗渗透性和屈服应力,从而显著改善 3D 打印砂浆的可施工性,最大打印层数比 33 层更高。同时,该工艺还改善了掺入 SF 的砂浆的力学性能。研究发现,在二氧化碳混合过程中,注入的二氧化碳迅速与钙离子反应生成 CaCO3,再与 C3A 反应生成单碳铝酸盐(Mc)。CO2 混合过程中钙离子的快速析出加速了 C3A 和 C3S 的水化,有助于早期龄期强度的快速发展和硬化砂浆性能的改善。在砂浆中加入 SF 大大提高了 CO2 混合的有益效果,因为 SF 是成核场所,在 CO2 混合过程中促进了 CaCO3 和 Mc 的形成。


Composites Science and Technology

A self-powered piezoelectric Poly(vinyl alcohol)/Polyvinylidene fluoride fiber membrane with alternating multilayer porous structure for energy harvesting and wearable sensors

Yaru Yu, Xiaowen Zhao, Huaiguo Ge, Lin Ye

doi:10.1016/j.compscitech.2023.110429

 

具有交替多层多孔结构的自供电压电聚(乙烯醇)/聚偏氟乙烯纤维膜,用于能量采集和可穿戴传感器

Development of flexible wearable electronic devices requires high-performance piezoelectric sensors, being advantageous in high sensitivity, ease to microintegration without external power supply. In this work, poly(vinyl alcohol) (PVA)/polyvinylidene fluoride (PVDF) fiber membranes with stable alternating multilayer structure were constructed through electrospinning and subsequent gas-phase crosslinking. The PVA/PVDF fiber was fully stretched with smooth surface and uniform diameter at appropriate PVDF concentration, exhibiting high porosity (88 %). The α-phase was transformed into the electroactive β-phase of PVDF in the electrospinning process, while the crystallinity and β-phase percentage (Fβ) were improved by mixing spinning of PVA and PVDF, with Fβ reaching above 90 %. The PVA/PVDF fiber membrane showed high mechanical strength/toughness and liquid absorbency (719.03 %). The significant electrical signal output (10.07 V and 166.42 nA) was generated, accompanying with high stress sensitivity, short response time and high stability, exhibiting excellent piezoelectricity and making the fiber membrane not only monitor large deformation movements of limbs as self-powered wearable sensor, but also sense weak signals of pulse, breathing etc. for monitoring human health, as well as environmental humidity. Meanwhile, the harvested energy could drive electronic device, showing prosperous potentials in fields of artificial intelligence.

柔性可穿戴电子设备的开发需要高性能的压电传感器,这些传感器具有灵敏度高、易于微集成且无需外部电源等优点。在这项工作中,通过电纺丝和随后的气相交联,构建了具有稳定交替多层结构的聚乙烯醇(PVA)/聚偏氟乙烯(PVDF)纤维膜。在适当的 PVDF 浓度下,PVA/PVDF 纤维完全拉伸,表面光滑,直径均匀,孔隙率高(88%)。在电纺丝过程中,PVDF 的 α 相转变为具有电活性的 β 相,而通过 PVA 和 PVDF 的混合纺丝,结晶度和 β 相百分比(Fβ)得到了改善,Fβ 达到了 90% 以上。PVA/PVDF 纤维膜具有较高的机械强度/韧性和吸液率(719.03%)。产生的电信号输出(10.07 V 和 166.42 nA)具有应力灵敏度高、响应时间短和稳定性高等特点,表现出优异的压电性,使纤维膜不仅能监测肢体的大变形运动,成为自供电的可穿戴传感器,还能感知脉搏、呼吸等微弱信号,用于监测人体健康和环境湿度。同时,采集到的能量可以驱动电子设备,在人工智能领域大有可为。



来源:复合材料力学仿真Composites FEM
ACTMechanicalOpticalSystemDeform振动复合材料非线性化学电源光学航空航天建筑电子消防材料人工智能
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首次发布时间:2024-11-05
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【新文速递】2023年12月23日复合材料SCI期刊最新文章

今日更新:Composite Structures 3 篇,Composites Part B: Engineering 6 篇,Composites Science and Technology 3 篇Composite StructuresComposite curved hourglass cellular structures: design optimization for stiffness response and crashworthiness performanceAmin Farrokhabadi, Dimitrios Chronopoulosdoi:10.1016/j.compstruct.2023.117834复合材料曲面沙漏蜂窝结构:刚度响应和防撞性能的优化设计Auxetic lattice structures are known for their superior stiffness-to-density and strength-to-density ratios. Re-entrant hourglass exhibits an acceptable equivalent elastic modulus and remarkable energy absorption capacity among various auxetic configurations due to their flexibility and hinge deflecting during crushing loads. This study introduces a curved hourglass honeycomb which can be produced using 3D printing with pure or reinforced filaments incorporating continuous fibers. New closed-form formulations are analytically derived using an energy method by considering an extracted unit cell to predict the equivalent in-plane mechanical properties for the first time. The plateau stress of the proposed honeycomb is evaluated at the densification state of a unit cell using the energy conservation theory, equating external work with plastic energy dissipation. The accuracy of these extended relations is validated against experimental outcomes, demonstrating good agreement between analytical and experimental results. Additionally, robust linear and nonlinear finite element analyses are conducted to assess the accuracy of the obtained relations, including the equivalent stiffness and plateau stress for structures produced with reinforced filaments. The nonlinear finite element code employs appropriate subroutines to model plasticity/damage events. Based on the established analytical relations for stiffness and plateau stress, multi-objective optimization using Genetic Algorithm is applied to define optimum values for the Pareto front chart's objective functions of stiffness and plateau stress. The optimization process involves exploring the design space and defining the values of geometrical parameters to achieve the desired objectives. In conclusion, this study presents a novel approach to developing curved re-entrant honeycomb structures, with analytical formulations validated against experimental and numerical results. Optimization helps to identify optimal configurations concerning stiffness and plateau stress, offering potential applications in lightweight and high-strength materials design. According to the obtained results, for selection of the best value for curved strut angle which results in the optimum value of stiffness and plateau stress, a range between 10°-34° can be considered depending on the volume fraction of fibers.辅助晶格结构以其优异的刚度密度比和强度密度比而闻名。在各种辅助结构中,重入式沙漏具有可接受的等效弹性模量和显著的能量吸收能力,这得益于它们的柔韧性和挤压载荷时的铰链偏转。本研究介绍了一种弧形沙漏蜂窝材料,这种材料可通过三维打印技术用纯纤维丝或包含连续纤维的增强纤维丝制成。通过考虑提取的单元格,使用能量法分析得出了新的闭式公式,首次预测了等效面内力学性能。利用能量守恒理论,将外功等同于塑性能量耗散,在单元格的致密化状态下评估了拟议蜂窝的高原应力。实验结果验证了这些扩展关系的准确性,表明分析结果与实验结果之间具有良好的一致性。此外,还进行了稳健的线性和非线性有限元分析,以评估所获得关系的准确性,包括使用增强丝制作的结构的等效刚度和高原应力。非线性有限元代码采用适当的子程序来模拟塑性/损伤事件。根据已建立的刚度和高原应力分析关系,采用遗传算法进行多目标优化,以确定帕累托前线图的刚度和高原应力目标函数的最佳值。优化过程包括探索设计空间和确定几何参数值,以实现预期目标。总之,本研究提出了一种开发曲面重入式蜂窝结构的新方法,并根据实验和数值结果验证了分析公式。优化有助于确定有关刚度和高原应力的最佳配置,为轻质和高强度材料设计提供了潜在应用。根据所获得的结果,要选择能产生最佳刚度和高原应力值的最佳弯曲支杆角度值,可根据纤维的体积分数在 10°-34° 之间进行考虑。Design of manufacturable variable stiffness composite laminates using spectral Chebyshev and normalized cut segmentation methodsMohammad Sheikhi, Mirmeysam Rafiei Anamagh, Bekir Bediz, Lutfi Taner Tuncdoi:10.1016/j.compstruct.2023.117836利用切比雪夫光谱法和归一化切割分割法设计可制造的可变刚度复合材料层压板The in-plane fiber orientations of variable stiffness (VS) laminates can be tailored to achieve enhanced structural properties compared to conventional constant stiffness (CS) laminates. However, VS laminate manufacturing faces challenges such as wrinkles, gaps, and overlaps. To address these challenges, we present a novel three-step design methodology. First, the laminate is modeled using lamination parameters (LPs) and the spectral Chebyshev method, and the optimal LPs are determined to maximize the fundamental frequency. Then, the discrete fiber angles are retrieved using the optimal LP distribution. Lastly, a normalized-cut segmentation method is applied to divide the domain into clusters and to generate manufacturable curvilinear fiber paths. Case studies focusing on designing clusters containing both straight and curvilinear fiber paths demonstrate that the designed VS composites can significantly enhance the dynamic performance with up to 20% enhancement in the fundamental frequency compared to CS laminates, under fully clamped boundary conditions with manufacturing constraints.与传统的恒定刚度(CS)层压板相比,可变刚度(VS)层压板的面内纤维取向可根据需要进行调整,以获得更强的结构特性。然而,VS 层压板的制造面临着褶皱、间隙和重叠等挑战。为了应对这些挑战,我们提出了一种新颖的三步设计方法。首先,使用层压参数(LP)和频谱切比雪夫方法对层压板进行建模,并确定最佳 LP,以最大限度地提高基频。然后,利用最优 LP 分布检索离散纤维角。最后,应用归一化切割分割法将域划分为簇,并生成可制造的曲线光纤路径。案例研究的重点是设计包含直线和曲线纤维路径的簇,结果表明,与 CS 复合材料相比,设计的 VS 复合材料能显著提高动态性能,在完全夹紧的边界条件和制造限制条件下,基频最多可提高 20%。Elliptical concrete-filled FRP tubes with an embedded H-shaped steel under axial compression and cyclic lateral loading: Experimental study and modellingBing Zhang, Yutao Peng, Sumei Zhang, Shuhong Lin, Chong Zhou, Guan Lindoi:10.1016/j.compstruct.2023.117839带有嵌入式 H 型钢的椭圆形混凝土填充玻璃钢管在轴向压缩和循环侧向载荷作用下的性能:实验研究与建模Concrete-filled FRP tubes (CFFTs) have found increasing applications due to their superior ductility and remarkable corrosion resistance. In published literature, circular CFFTs and rectangular CFFTs have been investigated extensively, while there are relatively few studies on elliptical CFFTs. There is no research about elliptical CFFTs with an embedded H-shaped steel (i.e., HS-ECFFTs) under axial compression and cyclic lateral loading. Against this background, this paper investigated the seismic behaviour of HS-ECFFTs experimentally and numerically. Test results indicated that: (1) all HS-ECFFTs performed well with remarkable energy dissipation ability; (2) due to the effective FRP confinement, the local buckling of the H-shaped steel was prohibited; (3) the elliptical aspect ratio had limited influences on the ductility, the stiffness degradation and the energy dissipation; (4) the FRP thickness, after a certain threshold, showed beneficial but limited influences on the peak load, the stiffness degradation and the energy dissipation; (5) the HS-ECFFT specimen performed much better in terms of the peak load, the ductility, the stiffness degradation and the energy dissipation when it was bending around the strong axis. The proposed numerical model established on the OpenSees platform could generate reasonably accurate numerical results for all HS-ECFFTs.混凝土填充玻璃纤维管道(CFFT)因其优越的延展性和显著的耐腐蚀性,应用日益广泛。在已发表的文献中,对圆形 CFFT 和矩形 CFFT 进行了广泛研究,而对椭圆形 CFFT 的研究相对较少。目前还没有关于在轴向压缩和循环侧向荷载下嵌入 H 型钢的椭圆 CFFT(即 HS-ECFFT)的研究。在此背景下,本文对 HS-ECFFT 的抗震性能进行了实验和数值研究。试验结果表明(1) 所有 HS-ECFFT 均表现良好,具有显著的耗能能力;(2) 由于玻璃钢的有效约束,H 型钢的局部屈曲被禁止;(3) 椭圆形长宽比对延性、刚度退化和耗能的影响有限;(5) HS-ECFFT 试样在绕强轴弯曲时,在峰值载荷、延性、刚度退化和能量耗散方面表现更好。在 OpenSees 平台上建立的拟议数值模型可以为所有 HS-ECFFT 生成相当精确的数值结果。Composites Part B: EngineeringA comparative study on the low velocity impact behavior of UD, woven, and hybrid UD/woven FRP composite laminatesBinlin Ma, Xiaofei Cao, Yu Feng, Yujian Song, Fei Yang, Ying Li, Deyue Zhang, Yipeng Wang, Yuting Hedoi:10.1016/j.compositesb.2023.111133 关于 UD、编织和 UD/ 编织混合 FRP 复合层压板低速冲击行为的比较研究This study is aimed at comparing the response and damage of unidirectional (UD), woven fabric (WF) and hybrid UD/WF fiber reinforced polymer (FRP) laminates subjected to low velocity impact. The unidirectional tape and/or woven fabric (plain weave) carbon/epoxy prepregs are laminated and hot-pressed to produce UD, WF and sandwich-like hybrid UD/WF specimens. Impact responses of specimens are determined through low velocity impact (LVI) tests with impact energies of 10 J, 17 J and 25 J. After the LVI tests, the damage of specimens is characterized and analyzed using a combination of visual inspection, ultrasonic phased-array inspection, micro-computed tomography (CT) inspection, cross-sectional microscopic observation, and thermal de-ply test. Also, the LVI damage mechanisms of the three types of specimens are quantitatively compared by using the inter fiber crack volume ratio, total delamination area and fiber fracture length. It is concluded that the fiber architecture plays an important role in determining low velocity impact behavior of composite laminates. Especially, for the sandwich-like hybrid UD/WF laminates whose surface is a WF layer and the core is a UD layer, the WF layer on the surface plays an important role in reducing matrix cracking, delamination and fiber fracture, thus improving its LVI resistance.本研究旨在比较单向(UD)、编织(WF)和 UD/WF 混合纤维增强聚合物(FRP)层压板在受到低速冲击时的响应和损坏情况。单向带和/或编织物(平纹)碳/环氧预浸料经层压和热压后可制成 UD、WF 和夹层式混合 UD/WF 试样。试样的冲击响应通过冲击能量为 10 J、17 J 和 25 J 的低速冲击(LVI)试验来确定。在 LVI 试验后,结合使用目视检查、超声相控阵检查、微型计算机断层扫描(CT)检查、横截面显微镜观察和热脱附试验,对试样的损伤进行表征和分析。此外,还利用纤维间裂纹体积比、总分层面积和纤维断裂长度对三种试样的 LVI 损伤机制进行了定量比较。结论是,纤维结构在决定复合材料层压板的低速冲击行为方面起着重要作用。特别是对于表面为 WF 层、核心为 UD 层的三明治状 UD/WF 混合层压板,表面的 WF 层在减少基体开裂、分层和纤维断裂方面发挥了重要作用,从而提高了其抗低速冲击性能。Fire-retardant braided electronic rope with a hierarchical core-shell structure for fire rescue operationsHaoran Gong, Zhiyong Peng, Yingcun Liu, Ze Chen, Shiyu Fei, Ruoxian Xu, Keshuai Liu, Duo Xu, Yizhu Guodoi:10.1016/j.compositesb.2023.111152用于消防救援行动的具有分层芯壳结构的阻燃编织电子绳索Effective rope rescue is crucial for evacuating individuals trapped in high-rise fires and for ensuring their safety in extreme fire environments. However, conventional fire rescue ropes often prioritize mechanical properties and flame retardancy, neglecting the crucial aspects of escape monitoring and position acquisition. Herein, we present a facile strategy to fabricate flame-retardant braided electronic rope (FBER) with a core-shell structure by large-scale braiding techniques. The pressure-sensing performance of the FBER was optimized by altering the braiding structure, which relies on the cross-contact between the core-braided composite yarns (CBCYs) at the sensing point. The unique structural design of FBER effectively prevents thermal transfer, ensuring pressure-sensing stability in extreme environments. Our results demonstrate that the FBER exhibits high sensitivity, rapid response, and excellent durability over 3500 cycles at 200 °C. The optimized FBER can be integrated into fire rescue detection systems for real-time escape monitoring, position acquisition, and safety detection during fire rescue operations. The scalable and multifunctional design of the FBER can significantly aid the development of fire rescue ropes.有效的绳索救援对于疏散高层火灾中的被困人员以及确保他们在极端火灾环境中的安全至关重要。然而,传统的消防救援绳索往往优先考虑机械性能和阻燃性能,而忽视了逃生监测和位置获取等关键环节。在此,我们提出了一种通过大规模编织技术制造具有芯壳结构的阻燃编织电子绳(FBER)的简便策略。通过改变编织结构,FBER 的压力传感性能得到了优化,这主要依赖于传感点处芯壳编织复合纱线(CBCY)之间的交叉接触。FBER 的独特结构设计有效地防止了热传递,确保了在极端环境下的压力传感稳定性。我们的研究结果表明,FBER 具有灵敏度高、响应速度快的特点,并且在 200 °C 的条件下可循环使用 3500 次,经久耐用。经过优化的 FBER 可集成到消防救援检测系统中,用于消防救援行动中的实时逃生监测、位置采集和安全检测。FBER 的可扩展性和多功能设计可极大地促进消防救援绳索的发展。Color adjustable, mechanically robust, flame-retardant and weather-resistant TiO2/MMT/CNF hierarchical nanocomposites coatings toward intelligent fire cyclic warning and protectionYan-Bin Shen, Ke-Xin Yu, Ye-Jun Wang, Yun-Hao Qu, Long-Qian Pan, Cheng-Fei Cao, Kun Cao, Jie-Feng Gao, Yongqian Shi, Pingan Song, Jianming Yong, Min Hong, Guo-Dong Zhang, Li Zhao, Long-Cheng Tangdoi:10.1016/j.compositesb.2023.111159颜色可调、机械坚固、阻燃和耐候的 TiO2/MMT/CNF 分层纳米复合材料涂层,用于智能火灾循环预警和保护Fire safety and protection are very important but still show a critical global challenge. Developing smart fire warning materials with combined passive flame retardancy and active fire alarm response is promising for reducing or avoiding blade fire disasters. Various nano-fillers (e.g., graphene oxide and MXene) based coatings have proven to be effective fire warning material for monitoring high fire risk of various combustible materials; however, they still show some shortages, for example, high cost, black color, poor weather resistance and complicated fabricating process. Here, we report a green, cost effective and large-scale strategy for fabricating water-based 3D-titania/2D-montmorillonite/1D-celluose nanofiber (TiO2/MMT/CNF) hierarchical nanocomposite coatings with adjustable color, mechanical robustness, good flame retardancy, long-term weather resistance and sensitive fire cyclic alarming response. The formation of strong chemical bonding and hydrogen bonding interactions among polyethylene glycol molecules and multi-scale nano-fillers together with silane surface modification can produce good mechanical flexibility (folded crane), surface hydrophobicity (water contact angle of 152°) and exceptional flame resistance (good structure integrity after 120 s flame exposure). Notably, the optimized nanocomposite coatings exhibit ultrafast fire alarm response (<3.5 s) and stable fire cyclic alarming capability via the possible band transition of the TiO2 network under flame. Further, such color-adjustable nanocomposite coatings can be easily fabricated for large-scale production, and they show excellent stable flame retardancy and stable fire cyclic warning response even after more than one-year outdoor exposure. This work provides a novel and green fire warning nanocomposite coatings with combined passive-active functionalities for fire warning and protection.消防安全和保护非常重要,但仍然是一个严峻的全球性挑战。开发兼具被动阻燃性和主动火灾报警响应功能的智能火灾预警材料,对于减少或避免叶片火灾灾难大有可为。各种基于纳米填料(如氧化石墨烯和 MXene)的涂层已被证明是有效的火灾预警材料,可用于监测各种可燃材料的高火灾风险;但它们仍存在一些不足,如成本高、颜色黑、耐候性差、制造工艺复杂等。在此,我们报告了一种绿色、低成本、大规模制造水基三维-钛/二维-蒙脱石/一维-纤维素纳米纤维(TiO2/MMT/CNF)分层纳米复合涂层的策略,该涂层具有颜色可调、机械坚固、阻燃性好、长期耐候性和灵敏的火灾循环报警响应等特点。聚乙二醇分子与多尺度纳米填料之间形成的强化学键和氢键相互作用,再加上硅烷表面改性,可产生良好的机械柔韧性(折叠式起重机)、表面疏水性(水接触角为 152°)和优异的阻燃性(120 秒火焰暴露后仍具有良好的结构完整性)。值得注意的是,优化后的纳米复合涂层具有超快的火灾报警响应(<3.5 秒)和稳定的火灾循环报警能力,这是通过二氧化钛网络在火焰下可能发生的带跃迁实现的。此外,这种颜色可调的纳米复合材料涂层易于制造,可进行大规模生产,即使在室外暴露一年以上,也能表现出优异的稳定阻燃性和稳定的火灾循环报警响应。这项研究提供了一种新型绿色火灾预警纳米复合涂料,具有被动和主动相结合的火灾预警和防护功能。Customized triphasic cartilage composite scaffold simulating hypoxic microenvironment for osteochondral regenerationChuan Guo, Zixuan Su, Lianghu Zhao, Renjin Chen, Yu Wang, Ye Wu, Haider Mohammed Khan, Walter Munesu Chirume, Zhigang Zhou, Pin Feng, Yuheng Liu, Chen Fan, Canyu Gao, Changchun Zhou, Qingquan Kong, Yujiang Fandoi:10.1016/j.compositesb.2023.111161 模拟缺氧微环境的定制三相软骨复合支架用于骨软骨再生The regeneration of the osteochondral complex in situ presents a significant challenge. The inherent hypoxic microenvironment of cartilage plays a critical role in facilitating osteochondral repair. The successful regeneration of the osteochondral complex necessitates the utilization of materials and structures that closely mimic its composition. In this study, carboxymethyl chitosan (CCS), oxidized hyaluronic acid (OHA), and tannic acid (Ta) were employed to fabricate an injectable and self-healing hydrogel (Ta@gel). The incorporation of Ta within the hydrogel network enables preferential oxidation, thereby creating an anoxic microenvironment within the hydrogel. Bone marrow-derived mesenchymal stem cells (BMSCs) were encapsulated within microspheres composed of methacrylic anhydride gelatin (GelMA). These microspheres were subsequently loaded into a Ta@gel. The resulting bionic hydrogel composite was then combined with a three-dimensional (3D) printed hydroxyapatite (HAp) scaffold coated with poly-l-lysine (PLL). This combination resulted in the formation of a bionic three-layer composite structure (HAp@PLL + Ta@gel + GelMA@BMSCs) that closely resembles the complex composition and structure of natural osteochondral complex. The efficacy of this customized triphasic composite scaffold in promoting osteochondral complex regeneration has been demonstrated in vitro and in vivo. Consequently, this study provided a new sight for inducing the in situ regeneration of cartilage.骨软骨复合体的原位再生是一项重大挑战。软骨固有的缺氧微环境在促进骨软骨修复方面起着至关重要的作用。要想成功实现骨软骨复合体的再生,就必须使用能密切模拟其成分的材料和结构。在这项研究中,羧甲基壳聚糖(CCS)、氧化透明质酸(OHA)和单宁酸(Ta)被用来制造一种可注射的自愈合水凝胶(Ta@gel)。在水凝胶网络中加入钽可实现优先氧化,从而在水凝胶中形成缺氧微环境。骨髓间充质干细胞(BMSCs)被包裹在由甲基丙烯酸酐明胶(GelMA)组成的微球中。随后将这些微球装入 Ta@ 凝胶中。然后,将生成的仿生水凝胶复合材料与涂有聚赖氨酸(PLL)的三维(3D)打印羟基磷灰石(HAp)支架相结合。这种组合形成了仿生三层复合结构(HAp@PLL + Ta@gel + GelMA@BMSCs),与天然骨软骨复合体的复杂成分和结构非常相似。这种定制的三相复合支架在促进骨软骨复合体再生方面的功效已在体外和体内得到证实。因此,这项研究为诱导软骨的原位再生提供了新的视角。Large-scale production of boron nitride nanosheets for flexible thermal interface materials with highly thermally conductive and low dielectric constantXiangdong Kong, Yapeng Chen, Rongjie Yang, Yandong Wang, Zhenbang Zhang, Maohua Li, Hanxi Chen, Linhong Li, Ping Gong, Jianxiang Zhang, Kang Xu, Yong Cao, Tao Cai, Qingwei Yan, Wen Dai, Xinfeng Wu, Cheng-Te Lin, Kazuhito Nishimura, Zhongbin Pan, Nan Jiang, Jinhong Yudoi:10.1016/j.compositesb.2023.111164 大规模生产具有高导热性和低介电常数的柔性热界面材料氮化硼纳米薄片As the operating power of electronic devices used in 5G technology continues to rapidly progress, demand is increasing for thermal conductive composites with exceptional dielectric insulating properties. Boron nitride nanosheets (BNNS)-based composites have garnered significant attention owing to the extraordinary inherent thermal conductivity and excellent dielectric insulation of BNNS. However, a bottleneck of mass exfoliation high-quality BNNS severely delays the advancement of BNNS-based composites. Herein, the large-scale production BNNS are attained through novel exfoliation method by rationally introducing vigorous ultrasonication treatment with an ultra-high power up to 1200 W. By acquiring approximately 32 g of high-quality BNNS in 5 cycles, the yield can be increased to around 40 %. The multilevel casting strategy prepared polydimethylsiloxane PDMS/BNNS composite exhibits a significantly enhanced κ⊥ of achieve to 3.82 W m−1 K−1 at 50 wt % of BNNS loading along with a low interfacial thermal resistance of 38 K mm2 W−1 and dielectric constant below 3. This finding provides a promising path for the massively producing high-quality BNNS and thermal interface materials to enhance thermal transport from electronics to heat sink.随着用于 5G 技术的电子设备的工作功率不断快速提高,对具有优异介电绝缘性能的导热复合材料的需求也在不断增加。基于氮化硼纳米片(BNNS)的复合材料因其非凡的固有热导率和优异的介电绝缘性能而备受关注。然而,高质量 BNNS 的大规模剥离瓶颈严重阻碍了 BNNS 基复合材料的发展。在此,通过合理引入高达 1200 W 的超高功率剧烈超声处理,采用新颖的剥离方法实现了 BNNS 的大规模生产。多层次浇铸策略制备的聚二甲基硅氧烷 PDMS/BNNS 复合材料在 BNNS 含量为 50 wt % 时,κ⊥ 显著增强,达到 3.82 W m-1 K-1,同时界面热阻低至 38 K mm2 W-1,介电常数低于 3。In-situ manipulation of TiB whisker orientation and investigation of its high-temperature mechanical properties in titanium matrix compositesQiang Wang, Zhao-Hui Zhang, Luo-Jin Liu, Xiao-Tong Jia, Yang-Yu He, Xian-Yu Li, Xing-Wang Chengdoi:10.1016/j.compositesb.2023.111165钛基复合材料中 TiB 晶须取向的原位控制及其高温力学性能研究“SPS pre-sintering + SPS reactive hot extrusion” (SPSHE) is a promising technique for manipulating the orientation of TiB whiskers (TiBw) in discontinuously reinforced titanium matrix composites (DRTMCs). In the current study, (12.4 vol % TiBw +2.9 vol % TiC)/Ti6Al4V composites were prepared using SPSHE technology, successfully achieving both the normalization of TiBw orientation and a high aspect ratio. Specifically, the [010] axis of TiBw was aligned with the extrusion direction, and the average aspect ratio was 24.86. Tensile tests were conducted on the DRTMC samples at temperatures of 873 K, 923 K, and 973 K. The results demonstrate that SPSHE significantly enhances the high-temperature strength of the composite. At 873 K, the DRTMC exhibited an exceptionally high tensile strength of 732.2 ± 20 MPa. The main strengthening mechanisms of the DRTMC include load transfer strengthening from TiBw and TiC particles, solution strengthening, fine grain strengthening and dislocation strengthening. Moreover, at 873 K and 923 K, the dominant failure mode of the reinforcement was a load-bearing fracture. However, as the test temperature increased to 973 K, a mixed failure mode of load-bearing fracture and interface debonding was observed in the reinforcement."SPS预烧结+SPS反应热挤压"(SPSHE)是操纵非连续增强钛基复合材料(DRTMC)中TiB晶须(TiBw)取向的一种很有前途的技术。本研究利用 SPSHE 技术制备了(12.4 vol % TiBw +2.9 vol % TiC)/Ti6Al4V 复合材料,成功实现了 TiBw 取向的正常化和高纵横比。具体来说,TiBw 的 [010] 轴与挤压方向一致,平均纵横比为 24.86。在 873 K、923 K 和 973 K 温度下对 DRTMC 样品进行了拉伸试验。在 873 K 时,DRTMC 的拉伸强度高达 732.2 ± 20 MPa。DRTMC 的主要强化机制包括 TiBw 和 TiC 颗粒的载荷传递强化、溶液强化、细晶粒强化和位错强化。此外,在 873 K 和 923 K 时,加固材料的主要破坏模式是承载断裂。然而,当试验温度升高到 973 K 时,在加固材料中观察到了承载断裂和界面脱粘的混合破坏模式。Composites Science and TechnologyExperimental and theoretical study on the electromagnetic shielding performance of polymer nanocomposites consisting of basalt fiber and CNTsZe-Xin Chen, Chao Chang, Xiu Yue, Hui Li, Cun-Guang Liang, Peng-Cheng Madoi:10.1016/j.compscitech.2023.110399 玄武岩纤维和碳纳米管聚合物纳米复合材料电磁屏蔽性能的实验和理论研究In this paper, we substantiated the mechanism behind the absorption and multiple reflection shielding in the nanocomposites (2 mm in thickness) consisting of basalt fiber loaded with carbon nanotubes and polydimethylsiloxane when exposed to the X-band frequency (8.2–12.4 GHz). The experimental results confirmed that the interface polarization, capacitor-like structure, together with internal conducting networks contributed to the electromagnetic shielding effect in the material. Furthermore, calculation and simulation were employed to analyze the propagation of electromagnetic wave within the nanocomposites, giving direct evidence that the electromagnetic irradiation could be efficiently absorbed while the reflection loss played a marginal role in this process. The findings of this study shed light on the structural design and optimization of the nanocomposites for high-efficiency electromagnetic shielding.在本文中,我们证实了由含碳纳米管和聚二甲基硅氧烷的玄武岩纤维组成的纳米复合材料(厚度为 2 毫米)在 X 波段频率(8.2-12.4 GHz)下产生吸收和多重反射屏蔽的机理。实验结果证实,界面极化、类似电容器的结构以及内部导电网络共同促成了材料的电磁屏蔽效应。此外,通过计算和仿真分析了电磁波在纳米复合材料内部的传播,直接证明了电磁辐照可被有效吸收,而反射损耗在此过程中的作用微乎其微。该研究结果为高效电磁屏蔽纳米复合材料的结构设计和优化提供了启示。Adjustable Ti2C3Alx-based segregated composite network for enhanced electromagnetic shielding and fire safetyWei Wang, Haowen Sun, Yuan Liu, Qi Wangdoi:10.1016/j.compscitech.2023.110400 基于 Ti2C3Alx 的可调节分隔复合网络,用于增强电磁屏蔽和防火安全With the rapid development of communication technology and portable electronic devices, the demand for the design of electronic devices with superior electromagnetic interference shielding and fire safety performance is increasing. Herein, epoxy resins (EPs) with typical segregated networks were designed by emulsion polymerization and adhesion self-assembly strategies and novel polyphosphonitrile microspheres (PZS) synthesized by precipitation polymerization were used to improve the fire safety of EP composites. It is worth noting that the oil-water (EP to water) ratio in emulsion polymerization is closely related to the microscopic morphology of the segregated network. A smaller ratio of EP to water results in more paths for electrical charge transfer through the EP composites. As a result, EP/PT-3 with a minimum oil-to-water ratio exhibits a high EMI SE (electromagnetic interference shielding effectiveness) in the X-band ranging from 40.12 to 40.30 dB at a loading of 7.20 vol% Ti3C2Alx. Besides, the synergistic action of the adjustable Ti3C2Alx network with PZS endows EP superior flame retardant performance. Compared with EP, the PHRR and THR values of EP/PT-3 are down 55.7 % and 72.6 %, respectively. There is no doubt that EP/PT-3 has provided a new route for the preparation of Ti3C2Alx-based electromagnetic shielding and fireproof materials.随着通信技术和便携式电子设备的快速发展,人们对设计具有优异电磁干扰屏蔽和防火安全性能的电子设备的要求越来越高。本文通过乳液聚合和粘附自组装策略设计了具有典型离析网络的环氧树脂(EP),并利用沉淀聚合合成的新型聚磷腈微球(PZS)提高了 EP 复合材料的防火安全性。值得注意的是,乳液聚合中的油水(EP 与水)比与离析网络的微观形态密切相关。EP 与水的比例越小,通过 EP 复合材料的电荷转移路径就越多。因此,油水比最小的 EP/PT-3 在装载 7.20 vol% Ti3C2Alx 时,在 X 波段表现出较高的 EMI SE(电磁干扰屏蔽效果),范围在 40.12 至 40.30 dB 之间。此外,可调节的 Ti3C2Alx 网络与 PZS 的协同作用赋予 EP 优异的阻燃性能。与 EP 相比,EP/PT-3 的 PHRR 和 THR 值分别下降了 55.7% 和 72.6%。毫无疑问,EP/PT-3 为制备基于 Ti3C2Alx 的电磁屏蔽和防火材料提供了一条新的途径。Fabrication of robust superhydrophobic surface on silicone rubberLie Chen, Gongqi Huang, Tao Hu, Qianliang Li, Jian Cheng, Dun Liudoi:10.1016/j.compscitech.2023.110401 在硅橡胶上制作坚固的超疏水表面Robust superhydrophobic surfaces with periodic array structures composed of circular silica islands on silicone rubber substrates were fabricated using a combination of multi-laser exposure and chemical modification. Abrasion tests with sandpaper demonstrate that hard silica regions on the surface can protect the silicone rubber region from external damage, resulting in long-lasting superhydrophobicity. Moreover, with an increase in area fraction and a decrease in array hole radius, the wear of the filled superhydrophobic silica is slowed while the protection for the silicone rubber region is enhanced. Particularly, the optimum surface geometry had an area fraction of 35 % and array hole radius of 100 μm retaining its hydrophobicity up to 63 times of abrasion, eight times more than that of the superhydrophobic surface processed by lasers alone. The results of a sand impact test confirmed the resulting surface's resilience in an aeolian sand environment. This research demonstrated the feasibility of producing robust, superhydrophobic surfaces on flexible silicone rubber substrates and providing a foundation for improving and innovating related products.利用多激光曝光和化学修饰相结合的方法,在硅橡胶基底上制造出了由圆形二氧化硅岛组成的周期性阵列结构的坚固超疏水表面。用砂纸进行的磨损测试表明,表面上坚硬的二氧化硅区域可以保护硅橡胶区域免受外部损伤,从而获得持久的超疏水性能。此外,随着面积分数的增加和阵列孔半径的减小,填充超疏水二氧化硅的磨损速度减慢,而对硅橡胶区域的保护作用增强。特别是,面积分数为 35 %、阵列孔半径为 100 μm 的最佳表面几何形状在 63 次磨损后仍能保持疏水性,是仅用激光加工的超疏水性表面的八倍。沙粒撞击测试结果证实了所产生的表面在风沙环境中的弹性。这项研究证明了在柔性硅橡胶基材上制作坚固的超疏水表面的可行性,并为改进和创新相关产品奠定了基础。来源:复合材料力学仿真Composites FEM

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