今日更新：Composite Structures 2 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 2 篇，Composites Science and Technology 4 篇Composite StructuresA novel modeling method to study compressive behaviors of 3D braided composites considering effects of fiber breakage and waviness defectsTao Liu, Danyang Wen, Qingliang Shen, Junhao Liang, Yue Chen, Zhi Fang, Mengyuan Zhang, Siqi Cheng, Yuxuan Gao, Xingzhong Gaodoi:10.1016/j.compstruct.2024.118206一种考虑纤维断裂和波纹缺陷影响的三维编织复合材料压缩特性建模新方法Fiber breakage and waviness defects are two significant and inevitable defects existing in three-dimensional braided composites (3DBCs). This work proposed a new method to create the numerical model containing fiber breakage and waviness defects at the micro-scale level according to experimental characterization results. The experimental tests of 3DBCs with various braiding angles and matrix types are then designed to verify the reliability and adaptability of the model. The results indicate that the fiber breakage and waviness defects both gave rise to an apparent decrease in the axial mechanical properties of the unidirectional and braided composites. The influences of two kinds of defects on 3DBCs are also related to the braiding angles. In addition, the effect of matrix type on the 3DBC is apparent that should not be neglected. The primary reasons of the change of compressive properties of 3DBCs with different matrix types are the variations of the matrix and interfacial properties. The proposed modeling method in this work can be extended for those composites that include a large quantity of fiber breakage and waviness defects.纤维断裂和波状缺陷是三维编织复合材料（3DBC）中不可避免的两种重要缺陷。本研究提出了一种新方法，即根据实验表征结果，在微观尺度上创建包含纤维断裂和波状缺陷的数值模型。然后设计了不同编织角度和基体类型的三维复合材料的实验测试，以验证模型的可靠性和适应性。结果表明，纤维断裂和波状缺陷都会导致单向复合材料和编织复合材料的轴向力学性能明显下降。两种缺陷对 3DBC 的影响还与编织角有关。此外，基体类型对 3DBC 的影响也是不容忽视的。不同基体类型的 3DBC 压缩性能变化的主要原因是基体和界面性能的变化。本文提出的建模方法可扩展用于包含大量纤维断裂和波状缺陷的复合材料。Numerical analysis of L-shaped wrinkling behavior of 3D woven preforms based on a novel hybrid element yarn modelZhi Yang, Lin Shi, Yanan Jiao, Junbo Xie, Xiaoying Cheng, Zhenyu Wu, Qingqing Nidoi:10.1016/j.compstruct.2024.118207基于新型混合单元纱线模型的三维机织预制件l形起皱行为数值分析Numerical simulation is a key means to evaluate the forming performance of 3D woven preforms (3DWPs). However, the macroscopic continuous model of 3DWPs cannot predict the orientation and deformation of yarns, while the microscopic discrete model is unsuitable for large-size samples forming simulation due to computational constraints. A novel mesoscopic hybrid element yarn model is thus proposed to establish a large-size 3D woven virtual yarn preform (VYP) model and the L-shaped virtual forming simulation model. The L-shaped forming experiment of the 3DWP is designed and executed, and the accuracy of the numerical simulation models is verified from three aspects: the mechanical curve, the sample's macroscopic morphology, and the local meso-structure features. Subsequently, the deformation behavior of the yarn structure inside the 3DWP during the L-shaped forming process is analyzed by combining experimental and simulation results. Furthermore, the effects of the L-shaped angle and chamfer radius on the deformation behavior of the 3DWP are studied, which helps guide the structural design of 3DWPs.数值模拟是评价三维编织预制件成形性能的重要手段。然而，3DWPs的宏观连续模型无法预测纱线的取向和变形，而微观离散模型由于计算的限制，不适合大尺寸样品成型模拟。为此，提出了一种新型的细观混合单元纱线模型，建立了大尺寸三维机织虚拟纱线预制件模型和l形虚拟成型仿真模型。设计并实施了3DWP的l形成形实验，并从力学曲线、试样宏观形貌和局部细观结构特征三个方面验证了数值模拟模型的准确性。随后，结合实验和仿真结果，分析了3DWP内纱线结构在l形成形过程中的变形行为。此外，还研究了l形角和倒角半径对3DWP变形行为的影响，有助于指导3DWP的结构设计。Composites Part A: Applied Science and ManufacturingProgressive damage modeling in open hole composite laminates with ultrasound-informed drilling-induced delaminationKirtunia Rahul, Arief Yudhanto, Pruthul Kokkada Ravindranath, David A. Jackdoi:10.1016/j.compositesa.2024.108262超声诱导钻井分层的裸眼复合材料层合板的渐进损伤建模Insertion of fasteners, often used in aerospace and automotive industries, requires drilling that induces non-uniform delamination between lamina of a carbon fiber reinforced plastic (CFRP). Understanding the effect of drilling-induced delamination on the mechanical performance and associated damage mechanisms (progressive damage and failure) is critical to ensure joining integrity. The present work develops an ultrasound testing (UT) method to quantify the drilling-induced delamination at each individual ply interface for CFRP laminates. We then develop a mesoscale finite element (FE) model of an open hole tension specimen by incorporating the UT-obtained drilling-induced delamination at each interface. This delamination is modeled using cohesive zone elements with a bilinear traction-separation law with progressive damage in each ply modeled using the 3D Hashin along with a progressive damage model. Our FE model, with UT-informed delamination, accurately predicts experimental observations of the stress concentration around the hole, damage progression, and open hole tension strength.紧固件的插入通常用于航空航天和汽车工业，需要钻孔，导致碳纤维增强塑料(CFRP)层之间不均匀分层。了解钻井引起的分层对机械性能和相关损伤机制(渐进性损伤和破坏)的影响，对于确保连接完整性至关重要。本工作开发了一种超声检测(UT)方法来量化CFRP层压板在每个单独层界面上的钻孔引起的分层。然后，我们将ut获得的每个界面上的钻井引起的分层结合起来，建立了裸眼拉伸试件的中尺度有限元(FE)模型。这种分层是使用具有双线性牵引-分离律的粘聚区单元来建模的，使用3D Hashin和渐进损伤模型来模拟每层的渐进损伤。我们的有限元模型具有ut信息分层，可以准确预测孔周围应力集中、损伤进展和裸眼抗拉强度的实验观察结果。Composites Part B: EngineeringPioneering the Carbon Fiber Frontier: A Half-Century of Industry Leadership and the Road AheadFumihiko Tanakadoi:10.1016/j.compositesb.2024.111515开拓碳纤维前沿:半个世纪的行业领先地位和未来之路Polyacrylonitrile (PAN)-based carbon fibers have been in full-scale industrialization for more than 50 years, during which time it has grown at an annual rate of 10-20% for half a century, a trend that is expected to continue. Throughout this period, the carbon fiber industry has supported the composites industry through a stable global supply and improved fiber quality. Here, we show PAN-based carbon fibers’ history and future for this 50-year milestone. The industrialization of carbon fiber began in 1959, when Shindo discovered how to stabilize PAN. The later discovery of comonomers based on the Morita-Baylis-Hilman reaction by Morita in 1966 further enabled industrialization. In addition to the innovativeness of this breakthrough, progress was made in converging technologies which intensified competition and encouraged incremental innovation. In recent years, microstructure control has become increasingly precise: down to the molecular level through incremental innovations, with tensile strength reaching 8.0 GPa and named T1200. Evaluating the carbon fibers’ intrinsic strength by the loop method, where evaluation size is reduced to the order of tens of micrometers, shows that the maximum value of T1200 is very high at 18 GPa. This is almost consistent with the value of 19 GPa predicted using molecular dynamics. Even higher strength can be expected by reducing defects. These performance improvements have already contributed toward carbon neutrality in aircraft and wind power generation. PAN-based carbon fibers will continue to be an important material in the future as further performance improvements and increased mass production are realized.聚丙烯腈(PAN)基碳纤维的全面工业化已经有50多年的历史，在此期间，它以每年10-20%的速度增长了半个世纪，预计这一趋势将继续下去。在此期间，碳纤维行业通过稳定的全球供应和提高纤维质量，为复合材料行业提供了支持。在这里，我们展示了pan基碳纤维的历史和未来，这是50年的里程碑。1959年，Shindo公司发现了稳定PAN的方法，从而开始了碳纤维的产业化。后来森田在1966年基于森田-贝利斯-希尔曼反应发现的共聚物进一步推动了工业化。除了这一突破的创新性之外，技术的融合也取得了进展，这加剧了竞争，鼓励了渐进式创新。近年来，微结构控制越来越精确，通过渐进式创新，微结构控制达到分子水平，抗拉强度达到8.0 GPa，命名为T1200。用环法评价碳纤维的固有强度，评价尺寸缩小到几十微米量级，表明T1200在18 GPa时的最大值非常高。这与分子动力学预测的19gpa值基本一致。通过减少缺陷，可以期望更高的强度。这些性能改进已经为飞机和风力发电的碳中和做出了贡献。pan基碳纤维在未来将继续成为一种重要的材料，因为它的性能得到了进一步的改善，并且实现了大规模生产。Thermomechanical fatigue behavior of CF/PEKK composite under low and ultrasonic frequenciesJafar Amraei, Tomasz Rogala, Andrzej Katunin, Aravind Premanand, Grzegorz Kokot, Dominik Wachla, Wacław Kuś, Marcin Bilewicz, Bilal Khatri, Frank Balledoi:10.1016/j.compositesb.2024.111539CF/PEKK复合材料在低频和超声下的热疲劳行为This study aimed to extract the thermomechanical fatigue behavior of a CF/PEKK composite under low and ultrasonic frequency fatigue tests (LFFTs and UFFTs) in the presence of the self-heating effect. Preliminary increasing amplitude tests (IATs) were performed to obtain the minimum load level at which the self-heating is observable. Extracting the fatigue strength from T-σ curves for three mean stress levels resulted in constructing S-N curves for the LFFT regime at different load levels using a shift procedure. However, combining LFFT and UFFT results via S-N curve was impractical, while joining such results through the heat dissipation rate (q) was feasible for various constant amplitude tests and IATs. The derived σ-q curves from combining LFFT and UFFT results and comparing the fracture mechanisms of CF/PEKK composite using fractography would make a step for bridging the transition zone between LFFTs and UFFTs and making the results transferable. The microscopy images obtained from fractography also confirmed the similarities of fatigue fracture mechanisms between LFFTs and UFFTs.本研究旨在提取 CF/PEKK 复合材料在低频和超声波疲劳试验（LFFTs 和 UFFTs）中存在自热效应时的热机械疲劳行为。进行了初步的增大振幅试验（IAT），以获得可观察到自热的最小载荷水平。从三个平均应力水平的 T-σ 曲线中提取疲劳强度后，利用移位程序构建了不同载荷水平下 LFFT 机制的 S-N 曲线。然而，通过 S-N 曲线合并 LFFT 和 UFFT 结果是不切实际的，而通过散热率（q）合并这些结果对于各种恒定振幅试验和 IAT 是可行的。通过结合 LFFT 和 UFFT 结果得出的 σ-q 曲线，并利用断裂显微镜比较 CF/PEKK 复合材料的断裂机理，将为弥合 LFFT 和 UFFT 之间的过渡区并使结果具有可移植性迈出一步。通过断裂显微镜获得的图像也证实了 LFFT 和 UFFT 疲劳断裂机制的相似性。Composites Science and TechnologyEnhanced thermal conductivity and mechanical property via improvement of hydrogen bonding between hexagonal boron nitride and aramid copolymerHwakyung Jeong, Jaegeun Lyu, Howon Choi, Min Woo Kim, Juyoung Kim, Hyeonsuk Yoo, Yongjin Lee, Ji Ho Youk, Han Gi Chaedoi:10.1016/j.compscitech.2024.110652 通过改善六方氮化硼与芳纶共聚物之间的氢键，提高了其导热性和力学性能This study focuses on enhancing thermal properties of aramid copolymer nanocomposites by integrating hexagonal boron nitride (hBN). Pristine hBN (P-hBN) is first subjected to oxidative heat treatment at 900 °C, producing thermally treated hBN (T-hBN), which significantly improves thermal conductivity while also increasing the tensile properties of composites. The study further explores the effect of different diamine co-monomers, 3,4’- and 4,4’-oxydianiline (ODA), on the nanocomposite properties. Both types of ODA-based composite films show improvement in various properties containing T-hBN. With 20 wt% of T-hBN, the 3,4'-ODA and 4,4'-ODA-based films exhibit 33.2% and 290% increase in tensile strength and thermal conductivity, respectively. The functionalization of hBN by heat treatment enhances the interaction between aramid copolymer and hBN and prevents the aggregation of hBN. The rough interface was shown in fractured images for films with T-hBN, suggesting that the composite films with T-hBN withstand higher external forces. In addition, it was observed that T-hBN exhibits better dispersion compared to P-hBN. This is supported by molecular dynamics (MD) simulation, and, in addition, it also provides the underlying mechanism for the property differences between both types of co-monomers.本文主要研究了通过集成六方氮化硼(hBN)来提高芳纶共聚物纳米复合材料的热性能。原始hBN (P-hBN)首先在900℃下进行氧化热处理，得到热处理后的hBN (T-hBN)，显著改善了复合材料的导热性，同时也提高了复合材料的拉伸性能。本研究进一步探讨了不同的二胺共单体3,4 ' -和4,4 ' -氧化二胺(ODA)对纳米复合材料性能的影响。两种类型的oda基复合膜均表现出含有T-hBN的各种性能的改善。当T-hBN添加量为20%时，3,4'-ODA和4,4'-ODA基薄膜的抗拉强度和导热系数分别提高了33.2%和290%。热处理使hBN功能化，增强了芳纶共聚物与hBN的相互作用，防止了hBN的聚集。含T-hBN的复合膜在断裂图像中显示出粗糙的界面，表明含T-hBN的复合膜承受更高的外力。此外，与P-hBN相比，T-hBN具有更好的分散性。这得到了分子动力学(MD)模拟的支持，此外，它还提供了两种类型的共聚单体之间性能差异的潜在机制。Enhanced interfacial, mechanical, and anti-hygrothermal properties of carbon fiber/cyanate ester composites with the catalytic sizing agents of titanium epoxyXu Peng, Yushan Wu, Yifan Li, Yu Xiang, Hantian Lu, Zhengli Hua, Faxiang Qin, Hua-Xin Pengdoi:10.1016/j.compscitech.2024.110658 环氧钛助剂增强了碳纤维/氰酸酯复合材料的界面性能、力学性能和抗湿热性能The mechanical properties of composites are closely related to the interfacial behavior, especially under the hygrothermal circumstance. A catalytic sizing agent of titanium epoxy is designed to enhance interfacial, mechanical, and anti-hygrothermal properties of high modulus carbon fiber (HMCF)/cyanate ester composites simultaneously. The mechanisms of interface enhancement and low hygroscopicity of composites are investigated. The titanium epoxy is synthesized and its catalytic effect on the curing of cyanate ester is proved. The interfacial properties of HMCF composites with catalytic sizing agents are improved to 95.5 MPa, which is attributed to the interphase with high crosslinking density and sufficient triazine rings and oxazolidinone structure due to preferential curing induced by interfacial catalysis, stimulating the smooth transition of interphase modulus. Further, the formed interphase exhibits few interface defects and low content of hydroxyl groups, which changes the moisture diffusion path and reduces saturated water absorption of composites to only 0.36%, resulting in the release of interfacial wet stress concentration and high retention of mechanical properties in hygrothermal environment. The resultant composites with high stiffness, excellent temperature resistance, superior dimensional stability and low moisture absorption are expected to be applied to high-orbit space, aerospace, precision instruments.复合材料的力学性能与界面行为密切相关，特别是在湿热环境下。为了同时提高高模量碳纤维(HMCF)/氰酸酯复合材料的界面性能、力学性能和抗湿热性能，设计了一种环氧钛催化施胶剂。研究了复合材料界面增强和低吸湿性的机理。合成了钛环氧树脂，并验证了其对氰酸酯固化的催化作用。添加了催化施胶剂的HMCF复合材料的界面性能提高到95.5 MPa，这是由于界面催化诱导的优先固化使界面相具有较高的交联密度和充足的三嗪环和恶唑烷酮结构，刺 激了界面相模量的平稳过渡。形成的界面相界面缺陷少，羟基含量低，改变了水分扩散路径，使复合材料的饱和吸水率降至0.36%，从而释放界面湿应力集中，在湿热环境下保持较高的力学性能。该复合材料具有高刚度、优异的耐温性、优越的尺寸稳定性和低吸湿性，有望应用于高轨道空间、航空航天、精密仪器等领域。Capillarity-assisted assembly of composite fibers to enable highly conductive fabrics for electromagnetic interference shieldingYing Lu, Jiali Xu, Yutong Liu, Jingling Ban, Xiufang Li, Mufang Li, Yang Zhou, Dong Wang, Longhai Piaodoi:10.1016/j.compscitech.2024.110659 复合纤维的毛细管辅助组装，使高导电织物能够屏蔽电磁干扰Poor adhesion between silver nanomaterials and substrates seriously restricts the development of electronic composite devices. In this work, flexible and conductive silver nanowires/fibroin/ degummed silk (AgNWs/fibroin/dSF) composite fibers with high adhesion and conductivity via capillarity-assisted assembly for electromagnetic interference (EMI) shielding are designed and fabricated by a facile and scalable all-solution dip-coating method. The nanocomposite fiber possesses high conductivity with a resistance of 8.8 Ω/cm at a low AgNWs/fibroin loading of 19.3 wt%. The assistance of the capillary force in the fiber highly increases the mass of deposited AgNWs. Furthermore, the AgNWs show high adhesion on the fibers in the tape-peel test. The enhanced deposition factors and mechanisms are detailly investigated. Moreover, the composite fibers are further woven into a soft and flexible fabric. The composite fabric shows an absorption-dominated EMI shielding performance with an efficient shielding effectiveness of 38 dB. The capillarity-assisted assembly is an attractive procedure for constructing high-conductive and uniform coatings for a wide application.银纳米材料与衬底的粘附性差严重制约了电子复合器件的发展。在这项工作中，通过毛细管辅助组装，设计和制造了具有高附附性和导电性的柔性导电银纳米线/丝素/脱胶丝(AgNWs/丝素/dSF)复合纤维，用于电磁干扰(EMI)屏蔽。该纳米复合纤维在AgNWs/丝素负载为19.3 wt%时具有8.8 Ω/cm的高电导率。纤维中毛细力的辅助作用极大地增加了沉积的AgNWs质量。此外，在胶带剥离测试中，AgNWs在纤维上显示出高附着力。详细探讨了增强沉积的因素和机理。此外，复合纤维进一步编织成柔软而有弹性的织物。复合材料具有以吸收为主的电磁干扰屏蔽性能，屏蔽效率为38 dB。毛细管辅助组装是一种具有广泛应用价值的高导电性、均匀涂层的制备方法。Enhanced thermoelectric properties of carbon nanotubes/polyaniline fibers through engineering doping level and orientationChun Zhang, Yalong Liu, Hui Li, Siqi Liu, Pengcheng Li, Han Zhang, Chaobin Hedoi:10.1016/j.compscitech.2024.110660 通过工程掺杂水平和取向增强碳纳米管/聚苯胺纤维的热电性能The rapid progress of miniaturized wearable electronics has put forward great requirements for organic fiber-based thermoelectric (TE) generators. Despite polyaniline (PANI) exhibits many outstanding attributes such as facile synthesis and low cost, as well as good environmental and thermal stability, only a few PANI-based fibers were fabricated and their TE efficiency needs to be further improved. In this work, the TE performance of wet-spun carbon nanotubes (CNTs)/PANI fibers was improved by synergistic engineering doping level of PANI and orientation of the fibers. The doping degree was optimized by varying coagulation baths, bath durations, and dopant loadings in the spinning solution, followed by fixing process during air drying to decrease shrinkage and enhance orientation of the fiber. Hexane coagulated CNTs/PANI fibers exhibited a higher doping degree of PANI compared to that of acetone and ethyl acetate, resulting in a maximum TE power factor of 77.4 μW m-1K-2 for 71 wt% CNTs/PANI fibers at PANI/dopant molar ratio of 2:1.25. Further fixing process induced a more oriented structure along the fibers, facilitating carrier transport and contributing to a significantly increased conductivity of 2155 S cm-1. Consequently, the CNTs/PANI fibers reached an optimal power factor of 91.8 μW m-1K-2. With outstanding TE performance and mechanical properties, the resultant fibers were assembled to fabricate a flexible TE generator, which generated a high output power of 2.5 nW with a temperature gradient of 10 K. These results demonstrate the potential of high-performance CNTs/PANI fibers to harvest body heat for the power supply of the wearable electronics.小型化可穿戴电子产品的快速发展对有机纤维热电发生器提出了很高的要求。尽管聚苯胺(PANI)具有合成简单、成本低、环境和热稳定性好的优点，但目前制备的聚苯胺基纤维数量较少，其TE效率有待进一步提高。本研究通过聚苯胺的工程掺杂水平和纤维取向的协同作用，提高了湿纺碳纳米管/聚苯胺纤维的TE性能。通过改变混凝浴、浴浴时间和纺丝液中掺杂量来优化掺杂程度，然后在风干过程中进行固定工艺，以减少收缩，增强纤维的取向性。与丙酮和乙酸乙酯相比，己烷混凝的CNTs/PANI纤维具有更高的PANI掺杂度，当PANI/掺杂摩尔比为2:25时，71% wt%的CNTs/PANI纤维的最大TE功率因数为77.4 μW m-1K-2。进一步的固定过程诱导了沿纤维方向更定向的结构，促进了载流子的运输，并显著提高了2155 S cm-1的电导率。因此，CNTs/PANI纤维的最佳功率因数为91.8 μW m-1K-2。合成的纤维具有优异的TE性能和机械性能，组装成柔性TE发生器，产生2.5 nW的高输出功率，温度梯度为10 K。这些结果表明，高性能碳纳米管/聚苯胺纤维有潜力收集人体热量，为可穿戴电子设备供电。来源：复合材料力学仿真Composites FEM
