今日更新：Composite Structures 8 篇，Composites Part A: Applied Science and Manufacturing 5 篇，Composites Part B: Engineering 3 篇，Composites Science and Technology 3 篇Composite StructuresAnalysis of the fracture behavior and mechanism of PIP-C/SiC composites at high temperaturesKunjie Wang, Chenghai Xu, Bo Gao, Leying Song, Songhe Mengdoi:10.1016/j.compstruct.2024.118491PIP-C/SiC复合材料高温断裂行为及机理分析The high-temperature fracture toughness of C/SiC composites is of great significance for the tolerance assessment and safety application of components in service. In this work, combining the high-temperature experimental technique and phase field method, the fracture toughness of PIP-C/SiC composites at 25–1600 ℃ in inert atmosphere was tested, and the microcrack propagation at different temperatures was simulated. The fracture model considers the effects of residual stress, temperature-dependent properties of constituents and interfacial graphitization on the crack propagation process. The results show that the fracture toughness and modes of C/SiC composites have significant temperature dependence and difference in in-plane and out-of-plane orientations. As the increase of temperature, the cracks exhibit three typical modes of deflection, penetration and long-debonding at the fiber–matrix interphase. It is worth noting that C/SiC composites show a unique fracture mode at 1600 ℃ with the work of fracture increasing significantly. Overall, the work provides a guidance for the damage tolerance assessment of C/SiC composites in engineering.C/SiC复合材料的高温断裂韧性对服役部件的公差评定和安全应用具有重要意义。本文将高温实验技术与相场法相结合，测试了PIP-C/SiC复合材料在25 ~ 1600℃惰性气氛下的断裂韧性，并模拟了不同温度下的微裂纹扩展。该断裂模型考虑了残余应力、组分温度相关特性和界面石墨化对裂纹扩展过程的影响。结果表明:C/SiC复合材料的断裂韧性和断裂模式具有显著的温度依赖性，且面内取向和面外取向存在显著差异;随着温度的升高，裂纹在纤维-基体界面处呈现出挠曲、穿透和长脱粘三种典型模式。值得注意的是，C/SiC复合材料在1600℃时呈现出独特的断裂模式，断裂功显著增加。研究结果对工程中C/SiC复合材料的损伤容限评价具有一定的指导意义。Development of a geometric modeling strategy for the generation of representative unit cells in 2D braidsJosé Rothkegel, Benjamin Renson, Michaël Bruyneel, Ludovic Noelsdoi:10.1016/j.compstruct.2024.118503二维编织中代表性单元细胞生成的几何建模策略的发展This article presents, tests and validates a method for generating representative unit cells of braided composites based on a geometrical approach. The method focuses on the geometry of the tows and uses surface minimization to obtain the minimal equivalent area of a central surface that is used for the generation of volumes and orthotropic mechanical properties of the tows. The homogenization of the yarns is solved using analytical equations and the homogenization of the cell is solved using a representative volume element technique. The robustness of the method is evaluated using a benchmark comparison with experimental and numerical results to validate the generated ge.ometry. The method is also tested and shown to be robust in modeling the geometry for several values of geometrical parameters of the tows without user intervention, including for configurations yielding a high cover factor.本文提出并试验验证了一种基于几何方法的编织复合材料代表性单元胞的生成方法。该方法侧重于拖曳的几何形状，并使用表面最小化来获得中心表面的最小等效面积，该中心表面用于生成拖曳的体积和正交异性力学特性。采用解析方程求解纱线的均匀化问题，采用代表性体积元技术求解单元的均匀化问题。通过与实验和数值结果的对比，验证了该方法的鲁棒性。该方法还经过了测试，结果表明，在没有用户干预的情况下，该方法在对拖曳几何参数的几个值进行几何建模方面具有鲁棒性，包括产生高覆盖系数的配置。Design optimization of lightweight automotive seatback through additive manufacturing compression overmolding of metal polymer compositesDeepak Kumar Pokkalla, Nikhil Garg, Mithulan Paramanathan, Vipin Kumar, Mitchell L. Rencheck, Peeyush Nandwana, Vlastimil Kunc, Ahmed Arabi Hassen, Seokpum Kimdoi:10.1016/j.compstruct.2024.118504 金属聚合物复合材料增材制造压缩复模轻量化汽车座椅靠背设计优化With the growing demand for enhanced automotive fuel efficiency and environmental sustainability, there is a need for lightweighting automotive components through innovative design and manufacturing processes. This study leverages a combination of numerical iterative design optimization and hybrid additive manufacturing – compression molding (AM-CM) technique for metal polymer composites to lightweight an automotive seatback. The AM-CM process enables robust mechanical interlocking between metals and composites, boasting high stiffness and strength with low overall density. Replacing metallic components with such metal polymer composites allows for comparable mechanical performance while significantly reducing the overall weight. First, the automotive seatback design space is reduced to critical load carrying regions using topology optimization and high stress concentration areas are identified using finite element analysis. Next, a lightweight metal polymer subcomponent is designed for a high stress concentration region. The full seatback frame with spatially heterogenous material-specific design is then iteratively optimized to enable enhanced stiffness with minimal weight. Overall, the automotive seatback frame designed with location-specific metal, polymer, and metal polymer composite materials weighs 20% less than the metal-only design while exhibiting similar stiffness.随着对提高汽车燃油效率和环境可持续性的需求不断增长，需要通过创新的设计和制造工艺来实现轻量化汽车零部件。本研究利用数值迭代设计优化和混合增材制造-压缩成型(AM-CM)技术相结合的金属聚合物复合材料轻量化汽车座椅靠背。AM-CM工艺能够在金属和复合材料之间实现强大的机械联锁，具有高刚度和强度，整体密度低。用这种金属聚合物复合材料代替金属部件，在显著降低整体重量的同时，具有相当的机械性能。首先，利用拓扑优化将汽车座椅靠背设计空间缩小到临界承载区域，并利用有限元分析确定高应力集中区域。其次，为高应力集中区设计了轻质金属聚合物子部件。然后，采用空间异质材料特定设计的全椅背框架进行迭代优化，以最小的重量增强刚度。总体而言，采用特定位置的金属、聚合物和金属聚合物复合材料设计的汽车座椅靠背框架比纯金属设计轻20%，同时具有相似的刚度。Characterization and analysis of conduction welded thermoplastic composite joints considering the influence of manufacturingB.H.A.H. Tijs, A. Turon, C. Bisagnidoi:10.1016/j.compstruct.2024.118505考虑制造影响的热塑性复合材料传导焊接接头的表征与分析Thermoplastic composite welding is a key technology that can help to make the aviation industry more sustainable, while at the same time enable high-volume production and cost-efficient manufacturing. In this work, characterization, testing and analysis of thermoplastic composite conduction welded joints is performed while accounting for the influence of the manufacturing process. Test specimens are designed from welds of a half a meter long welding tool that is developed to weld the stiffened structures of the next-generation thermoplastic composite fuselage. In the design, special attention is paid to the weldability of the laminates, while ensuring fracture occurs only at the welded interface. Two specimen configurations are evaluated for the Double Cantilever Beam and End-Notched Flexure characterization tests. Moreover, Single Lap-Shear specimens are tested in tension and in three-point-bending. Finally, the characterized material properties are introduced in finite element analyses to demonstrate that the cohesive zone modeling approach can be used to conservatively predict the strength of these welded joints. New insights are obtained in the relation between the manufacturing process, the quality of the weld and the mechanical properties of the joints, which are significantly different compared to autoclave consolidated composites.热塑性复合材料焊接是一项关键技术，可以帮助航空业更具可持续性，同时实现大批量生产和成本效益制造。本文对热塑性复合材料导电焊接接头进行了表征、测试和分析，同时考虑了制造工艺的影响。测试样品是由半米长的焊接工具设计的，该焊接工具是为焊接下一代热塑性复合材料机身的强化结构而开发的。在设计中，特别注意层压板的可焊性，同时确保仅在焊接界面处发生断裂。两种试样配置评估双悬臂梁和端缺口弯曲表征试验。此外，还对单弯剪试件进行了拉伸和三点弯曲试验。最后，在有限元分析中引入了表征的材料性能，证明了黏聚区建模方法可以保守地预测这些焊接接头的强度。在制造工艺、焊缝质量和接头力学性能之间的关系方面获得了新的见解，这与热压釜固结复合材料相比有明显的不同。Development of a numerical and analytical methodology for analyzing hybrid laminates with multi-oriented piezoelectric and structural layersJanice Longo, Matheus Rodrigues Silva, Humberto Brito-Santana, António J.M. Ferreira, Volnei Tita, Ricardo de Medeirosdoi:10.1016/j.compstruct.2024.118506发展了一种多取向压电层和结构层混合层板的数值分析方法Piezoelectric materials can generate an electrical response under mechanical stress, functioning as sensors. Conversely, applying an electrical field to these materials enables precise motion control, making them effective as actuators. This work focuses on evaluating the effective properties of hybrid multi-oriented composite laminates consisting of structural and piezoelectric layers driven by monoclinic constitutive equations. Square unit cell model was used to calculate all coefficients of the material tensor. The finite element (FE) homogenization method and periodic boundary conditions implemented by node-to-node constraint equations are used to study a representative volume element (RVE) modeled as three-layer unit cell in the mesoscale. The pre-processing, FE analysis, and post-processing are conducted in the FE package ABAQUSⓇ through Python scripts. The computational approach yields results that align closely with the analytical effective coefficients derived from the Asymptotic Homogenization Method (AHM), demonstrating the robustness and accuracy of our methodology.压电材料可以在机械应力下产生电响应，起到传感器的作用。相反，在这些材料上施加电场可以实现精确的运动控制，使它们成为有效的致动器。本文研究了单斜本构方程驱动下由结构层和压电层组成的杂化多取向复合材料层合板的有效性能。采用平方单元胞模型计算材料张量的所有系数。采用有限元均匀化方法和节点对节点约束方程实现的周期边界条件，研究了一种具有代表性的中尺度三层单元格体单元。预处理、有限元分析和后处理在有限元包ABAQUSⓇ中通过Python脚本进行。计算方法产生的结果与从渐近均匀化方法(AHM)导出的解析有效系数密切一致，证明了我们的方法的鲁棒性和准确性。Identification of mode I fracture toughness in GFRP/Al and GFRP/Cu joints for structural batteriesMaryam Niazi, Federico Danzi, Ricardo Carbas, Pedro P. Camanhodoi:10.1016/j.compstruct.2024.118509结构电池用GFRP/Al和GFRP/Cu接头的I型断裂韧性鉴定Fibre metal laminates (FMLs) have been proposed as components of structural batteries, yet their elastic mismatch can lead to interface cracks, compromising structural integrity and both mechanical and electrochemical efficiency. To this end, the bonding between the metal and the composite layer is of utmost importance. In this study, the effect of various metal surface treatments on the mode I interlaminar fracture toughness of two FML configurations suitable for structural batteries—Glass Fibre Reinforced Polymer (GFRP)/aluminum laminate and GFRP/copper laminate—was examined. The surface treatments included sulfo-ferric etching, NaOH/HNO3 etching, and Sol-Gel anodizing for aluminum 2024-T3, as well as FeCl3/HCl/Glycerol treatment and Sol-Gel anodizing for copper alloy. The results were compared with untreated conditions and with the baseline GFRP/GFRP configuration. GFRP/metal coupons were designed to achieve pure mode I interlaminar fracture toughness in double cantilever beam (DCB) tests, and the designs were verified using the Virtual Crack Closure Technique (VCCT). The surface characterization of the metals was performed using contact angle tests to estimate the surface free energy, while Coherence Scanning Interferometry (CSI) was used to measure the surface roughness and topography.金属纤维层压板(FMLs)已被提出作为结构电池的组件，但其弹性失配会导致界面裂缝，从而影响结构完整性以及机械和电化学效率。为此，金属和复合层之间的结合是至关重要的。在本研究中，研究了不同金属表面处理对两种适用于结构电池的FML结构——玻璃纤维增强聚合物(GFRP)/铝层压板和GFRP/铜层压板的I型层间断裂韧性的影响。铝2024-T3的表面处理包括硫铁蚀刻、NaOH/HNO3蚀刻和溶胶-凝胶阳极氧化，铜合金的表面处理包括FeCl3/HCl/甘油处理和溶胶-凝胶阳极氧化。将结果与未经治疗的情况和基线GFRP/GFRP配置进行比较。在双悬臂梁(DCB)试验中，设计了GFRP/金属板，以实现纯I型层间断裂韧性，并使用虚拟裂纹闭合技术(VCCT)对设计进行了验证。金属的表面表征采用接触角测试来估计表面自由能，而相干扫描干涉测量(CSI)用于测量表面粗糙度和形貌。A mesoscale mechanical model of needle-punched carbon/carbon composite with beam-brick combined elementYehan Fan, Chuwei Zhou, Yingxuan Zhang, Zhongxiao Zhang, Xin Li, Xuanze Yan, Wangchao Fengdoi:10.1016/j.compstruct.2024.118510含梁砖复合单元的针 刺碳/碳复合材料中尺度力学模型Needle punching carbon/carbon composite (NP C/C) has merits of high specific stiffness and strength and especially of excellent high-temperature strength retention, meanwhile it possesses improved interlaminate strength with relatively low manufacturing cost. But the needle punching technology may damage its in-plane properties for introducing local defeats inevitably. A mechanical prediction of NP C/C reflecting its meso-scale architectural features is desired.In this study, a beam-brick combined finite element (BBE) model was developed for predicting the mechanical behaviors and damage processes of NP C/C. In this model, beam elements represent the fiber directional properties in unidirectional fiber cloth (UDC) ply and short cut fiber felt (SCF) ply, while brick elements simulate properties of other directions in them. The displacement compatibility between beam and brick elements was established via their shape functions. The damage laws were employed in these two elements. The proposed model was used to simulate tensile and compressive experiments of an NP C/C and good agreements with test data were found. This BBE model can characterize the meso-structure and main mechanical behaviors of NP C/C and its meso-structure modeling is simpler and the computation requirement is lower compared with the traditional meso-mechanic models which built all with brick elements.针冲碳/碳复合材料(NP C/C)具有较高的比刚度和强度，特别是具有优异的高温强度保持性，同时具有较好的层间强度和较低的制造成本。但针冲技术不可避免地会因引入局部缺陷而破坏其面内特性。需要一个反映其中尺度结构特征的NP C/C的力学预测。在本研究中，建立了用于预测NP - C/C的力学行为和损伤过程的梁-砖组合有限元模型。在该模型中，束单元表示单向纤维布(UDC)层和短切纤维毡(SCF)层中纤维的方向特性，砖单元模拟其中其他方向的特性。通过梁与砖的形状函数，建立了梁与砖的位移协调关系。损害法适用于这两个要素。将所提出的模型应用于NP - C/C的拉伸和压缩试验，与试验数据吻合较好。该模型能较好地表征NP - C/C的细观结构和主要力学行为，与传统的全砖细观力学模型相比，其细观结构建模更简单，计算量更低。Physics-constrained deep learning approach for solving inverse problems in composite laminated platesYang Li, Detao Wan, Zhe Wang, Dean Hudoi:10.1016/j.compstruct.2024.118514求解复合材料层合板逆问题的物理约束深度学习方法The applications of physics-informed neural networks (PINNs) in material parameters identification of composite laminates are currently research highlights. We present an efficient physics-constrained deep learning approach based on PINNs for solving material parameters of composite laminates. We explain the details of incorporating first-order shear deformation theory as physical information into designed loss functions. The performance of proposed approach is demonstrated through a numerical example of idealized composite laminated plates under uniform pressure conditions. The computational errors of material parameters are less than 0.1%. Moreover, the applicability of transfer learning (TL) has been illustrated for inversion of material parameters with few datasets. The ambition is to improve the identification efficiency of carbon and glass fiber reinforced plies material parameters across various loading conditions. Intensive studies are conducted to compare convergence time between with and without TL through a numerical example under thermal-force coupling conditions. The comparison shows PINNs with TL obtain average error of 0.144% and 0.077% in carbon and glass fiber reinforced plies, which is better than without TL of 0.472% and 0.284%, respectively. The proposed work emphasizes the effective application of PINNs-based approach that combines first-order deformation and data-driven solution features for inverse solving material parameters of composite laminates.物理信息神经网络(pinn)在复合材料层合板材料参数识别中的应用是目前研究的热点。我们提出了一种有效的基于pinn的物理约束深度学习方法来求解复合材料层合板的材料参数。我们解释了将一阶剪切变形理论作为物理信息纳入设计损失函数的细节。通过均匀压力条件下理想复合材料层合板的数值算例验证了该方法的性能。材料参数的计算误差小于0.1%。此外，迁移学习(TL)在少量数据集的材料参数反演中的适用性也得到了证明。目标是提高碳和玻璃纤维增强层材料参数在不同载荷条件下的识别效率。通过一个热力耦合条件下的数值算例，对有TL和无TL的收敛时间进行了深入研究。对比结果表明，在碳纤维和玻璃纤维增强层中，加TL的pinn平均误差为0.144%和0.077%，优于不加TL的0.472%和0.284%。本文强调了基于pons的方法的有效应用，该方法结合了一阶变形和数据驱动的解特征来反求解复合材料层合板的材料参数。Composites Part A: Applied Science and ManufacturingDependence of the mechanical properties of nylon-carbon fiber composite on the FDM printing parametersA. Gómez-Ortega, S. Piedra, G.C. Mondragón-Rodríguez, N. Camachodoi:10.1016/j.compositesa.2024.108419 尼龙-碳纤维复合材料力学性能对FDM打印参数的影响Nylon-based polymer reinforced with short carbon fibers (PA-CFs), fabricated using the Fused Deposition Modeling (FDM) 3D printing process, has been proposed for various applications. However, the mechanical performance of these materials as a function of printing parameters, including wall thickness at infill contents < 100 %, has yet to be reported in the literature. This paper focuses on the effects of infill percentage, nozzle temperature, and wall thickness on the porosity content, microstructure, and mechanical properties of PA-CF specimens. Employing a Taguchi (L9 − 3^3) design of experiments, tensile and flexural testing were conducted to assess their mechanical response. The printing temperature induces microstructural changes, promoting interlayer debonding due to voids and pores at wall- and skin-core interfaces. Wall thickness significantly impacts tensile strength and can be maintained between 0.8 and 1.35 mm for maximum flexural strength, while maximal tensile strength can only be achieved with a wall thickness between 1.15 and 1.5 mm.采用熔融沉积建模(FDM) 3D打印工艺制备的尼龙基短碳纤维增强聚合物(PA-CFs)已被提出用于各种应用。然而，这些材料的力学性能作为打印参数的函数，包括填充物含量 < 100 %时的壁厚，尚未在文献中报道。本文主要研究了填充率、喷嘴温度和壁厚对PA-CF试样孔隙率、微观结构和力学性能的影响。采用田口(L9−3^3)实验设计，进行拉伸和弯曲测试以评估其力学响应。打印温度引起微观结构的变化，促进了由于壁和皮核界面上的空隙和孔隙而产生的层间脱粘。壁厚对抗拉强度影响显著，最大抗弯强度可保持在0.8 ~ 1.35 mm之间，而最大抗拉强度只能在1.15 ~ 1.5 mm之间实现。Characterization of thermomechanical properties and damage mechanisms using acoustic emission of Lygeum spartum PLA 3D-printed biocomposite with fused deposition modellingKhalil Benabderazag, Zouheyr Belouadah, Moussa Guebailia, Lotfi Toubaldoi:10.1016/j.compositesa.2024.108426利用声发射表征Lygeum spartum PLA 3d打印生物复合材料的热力学性能和损伤机制与熔融沉积建模This study examines the morphological, physicochemical, mechanical, and thermal properties of 3D-printed biocomposite fabricated using fused deposition modeling (FDM) with short Lygeum spartum fibers and PLA. Scanning electron microscopy (SEM) was used to analyze fracture surfaces and fiber dispersion within the PLA matrix after mechanical testing. Chemical and thermal properties were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Mechanical performance was assessed through tensile and flexural testing, supplemented by digital image correlation (DIC) and acoustic emission techniques. The incorporation of 10% short natural fibers mitigated the brittle behavior of 3D-printed PLA, resulting in a more ductile biocomposite. These materials exhibited improved mechanical and thermal properties, including increased flexural modulus, higher elongation at break, and enhanced thermal stability compared to neat PLA. These findings underscore the potential of these biocomposites as biodegradable and eco-friendly materials for various applications.本研究考察了使用熔融沉积建模(FDM)和短Lygeum spartum纤维和PLA制造的3d打印生物复合材料的形态、物理化学、机械和热性能。采用扫描电子显微镜(SEM)对力学测试后的聚乳酸基体的断裂面和纤维分散进行了分析。利用傅里叶红外光谱(FTIR)、热重分析(TGA)和差示扫描量热法(DSC)对其化学和热性质进行了表征。机械性能通过拉伸和弯曲测试进行评估，辅以数字图像相关(DIC)和声发射技术。10%天然短纤维的掺入减轻了3d打印PLA的脆性行为，从而产生更具延展性的生物复合材料。与纯PLA相比，这些材料表现出更好的机械和热性能，包括增加的弯曲模量，更高的断裂伸长率和增强的热稳定性。这些发现强调了这些生物复合材料作为可生物降解和环保材料在各种应用中的潜力。The electrically controlled dimming film of thiol-vinyl ether system with low-voltage and high contrast ratio for smart windowsYue Feng, Jianjun Xu, Baohua Yuan, Longxiang He, Luoning Zhang, Yongchuan Hu, Liezheng Lyu, Cheng Zou, Qian Wang, Meina Yu, Yuanwei Chen, Yanzi Gao, Huai Yangdoi:10.1016/j.compositesa.2024.108427 智能窗用低电压、高对比度的电控巯基乙烯醚调光膜As a type of smart window, polymer dispersed liquid crystal (PDLC) electrically controlled dimming film can respond to external electrical stimuli to regulate the optical flux of sunlight, reducing energy consumption. Herein, a PDLC film was prepared by systematically studying the functionalities and structural compatibility of vinyl ether and thiol compounds, and the optimal PDLC film possesses a superior contrast ratio (CR) of 196.9. When the film thickness is adjusted to 8 μm, the film saturation voltage is reduced to 6.7 V, still maintaining a high CR of 48.4. The well-designed PDLC films exhibited excellent modulation of light. The temperature difference between PDLC film and bare ITO glass can reach 4 °C under the simulated sunlight test, demonstrating the good thermal insulation performance. This smart films with low power consumption and high CR can meet the demand for active regulation of optical flux on smart windows.聚合物分散液晶(PDLC)电控调光膜作为智能窗口的一种，可以响应外界的电刺 激来调节太阳光的光通量，降低能耗。本文通过系统地研究乙烯醚和巯基化合物的功能和结构相容性，制备了PDLC膜，最佳的PDLC膜具有优异的对比度(CR)为196.9。当薄膜厚度调整为8 μm时，薄膜饱和电压降至6.7 V，仍保持48.4的高CR。设计良好的PDLC薄膜具有优异的光调制性能。在模拟日光下，PDLC膜与裸ITO玻璃的温差可达4 ℃，显示出良好的隔热性能。该智能薄膜具有低功耗、高CR的特点，能够满足智能窗口光通量主动调节的需求。Spatiotemporal prediction of surface roughness evolution of C/C composites based on recurrent neural networkTong Shang, Jingran Ge, Jing Yang, Maoyuan Li, Jun Liangdoi:10.1016/j.compositesa.2024.108429基于递归神经网络的C/C复合材料表面粗糙度时空预测Carbon/carbon (C/C) composites are widely used in aerospace applications due to their excellent properties. Their surface roughness is an important factor affecting the material properties and ablation resistance, which is essential for the accurate prediction of the material. Images are often used to summarize and characterize microstructural features, which include information such as fiber microstructure and fiber orientations. An ablation shape evolution model based on optimization of attention mechanism, which combines multi-scale convolutional neural network (MSCNN) and long short-term memory (LSTM) methods for the C/C composites, is proposed. MSCNN encodes the microstructural information of the ablation image, which is fed into the LSTM model to extract the spatiotemporal features and long-term dependencies latent in the temporal law. The attention mechanism is used to assign different weights to the extracted features which makes the model focus more on the important time steps in the sequence. The results show that the proposed model achieves excellent effects in predicting the evolution of ablative morphology, with high agreement with the simulated values. The method saves time and cost, while providing an efficient and reliable method for the design and optimization of thermal protection materials.碳/碳(C/C)复合材料由于其优异的性能在航空航天领域得到了广泛的应用。其表面粗糙度是影响材料性能和抗烧蚀性能的重要因素，对材料的准确预测至关重要。图像通常用于总结和表征微观结构特征，其中包括纤维微观结构和纤维取向等信息。结合多尺度卷积神经网络(MSCNN)和长短期记忆(LSTM)方法，提出了一种基于注意机制优化的C/C复合材料烧蚀形状演化模型。MSCNN对消融图像的微结构信息进行编码，并将其输入到LSTM模型中，提取时间规律中隐含的时空特征和长期依赖关系。利用注意机制对提取的特征赋予不同的权重，使模型更加关注序列中重要的时间步长。结果表明，该模型对烧蚀形貌的预测效果较好，与模拟值吻合度较高。该方法节省了时间和成本，同时为热防护材料的设计和优化提供了一种高效可靠的方法。Preparation and sensing properties of multiscale conductive filler hybrid CNTs@Ag-MXene-TPU/TPU double-layer strain sensing materialsYanzhi Cai, Dengpeng Chen, Laifei Cheng, Siyu Guo, Zhongyi Hu, Yuhan Wang, Haiming Yu, Yuan Zhoudoi:10.1016/j.compositesa.2024.108430多尺度导电填料复合CNTs@Ag-MXene-TPU/TPU双层应变传感材料的制备及其传感性能The performance of sensors is often limited by the structural characteristics of the single form of conductive filler, making it difficult for sensors to simultaneously consider the broad sensing range and high sensitivity. How to achieve high sensitivity and broad working range of sensors through innovative sensing materials and sensor structure design remains a challenge. Here, a flexible sensor with multidimensional sensing materials and a double-layer structure is constructed. It consists of a high-performance CNTs@Ag-MXene-TPU sensing layer and a TPU flexible layer with significant deformability. Thanks to the synergistic effect of the double-layer structure and multidimensional sensing materials, this sensor has a high sensitivity of up to maximum gauge factor of 12216.3 and a wide sensing range of 300 %. Its response time and recovery time can reach 200 and 250 ms, respectively, and it also exhibits excellent cycling stability.传感器的性能往往受到单一形式导电填料的结构特性的限制，使得传感器难以同时考虑宽的传感范围和高的灵敏度。如何通过创新的传感材料和传感器结构设计来实现传感器的高灵敏度和宽工作范围仍然是一个挑战。本文构建了一种具有多维传感材料和双层结构的柔性传感器。它由高性能CNTs@Ag-MXene-TPU传感层和具有显著可变形性的TPU柔性层组成。由于双层结构和多维传感材料的协同作用，该传感器具有高灵敏度，最大测量因子可达12216.3，传感范围可达300 %。其响应时间和恢复时间可分别达到200和250 ms，并具有良好的循环稳定性。Composites Part B: EngineeringPredicting damping in geometrically complex composite structures via increased interlaminar homogenisationT. Mace, C.W. Schwingshackldoi:10.1016/j.compositesb.2024.111769通过增加层间均匀化预测几何复杂复合结构中的阻尼The widespread adoption of composite materials across the engineering sector requires that the vibration behaviour of these materials is more readily taken into account for new component designs. Current prediction methods are often prohibitively complex or expensive for such applications, or are restricted to very simple geometries. A simplified approach, shown previously by the authors to generate accurate and inexpensive predictions, is extended to geometrically more complex test cases in this work. The novel technique is shown to hold up well compared to the more established ‘layered’ approach, outperforming such predictions in some cases and highlighting the general applicability of the approach for damping predictions in general composite components.复合材料在工程领域的广泛应用，要求在设计新部件时更容易考虑到这些材料的振动特性。当前的预测方法对于此类应用来说通常过于复杂或昂贵，或者仅限于非常简单的几何形状。作者先前展示的一种简化的方法可以生成准确且廉价的预测，在这项工作中被扩展到几何上更复杂的测试用例。与更成熟的“分层”方法相比，新技术表现良好，在某些情况下优于此类预测，并突出了该方法在一般复合材料部件阻尼预测中的普遍适用性。Impact characteristics of S2-glass fibre/FM94-epoxy composites under high and cryogenic temperatures: experimental and numerical investigationAhmad S.M. Al-Azzawi, C.A. Featherston, Colin Lupton, Chulin Jiang, Antigoni Barouni, Ugur Koklu, Khaled Giasindoi:10.1016/j.compositesb.2024.111786高温和低温下s2 -玻璃纤维/ fm94 -环氧复合材料的冲击特性:实验和数值研究The aerospace industry uses glass fibre reinforced polymer (GFRP) composites to manufacture structural and non-structural parts of an aircraft as they possess superior strength to weight ratio and exceptional corrosion resistance. Commercial aircraft operate in a very wide temperature ranges from -54 to 55 °C. Potential GFRP laminates are susceptible to impact during aircraft operation, and the temperature at impact governs the nature of damage and failure mechanisms. As a result, the current study focuses on examining how aeronautical GFRP composites behave in various temperature environments that are encountered during high- and low-altitude operations. Using S2-glass fibre/FM94-epoxy unidirectional prepreg, GFRP plates were created. Drop weight impact tests were conducted at ambient (25 °C), high (50, 75, 100 °C), and low (-25, -55 °C) temperatures, as well as at various impact energies (75, 150, 225 J). The damages were assessed visually, along with their sizes. Each testing scenario's impact parameters, including the impact load, deflection, and energy absorption, were also examined. In Abaqus/Explicit, a coupled temperature-displacement numerical model was created to predict the onset of stress and damage. According to experimental findings, GFRP plates are stiffer and show less apparent damage at cryogenic temperatures (∼15-34% lower displacement) than they do at other temperatures. Furthermore, it was observed that the matrix softens at high temperatures, showing larger damaged area at entry but with less obvious damage and increasing energy absorption, while semi-perforation occurred under cryogenic temperatures at entry with smaller damaged area. A strong correlation is shown between the experimental and FE data, confirming the capability of FE models to predict impact damage and deflections at different temperatures in the future.航空航天工业使用玻璃纤维增强聚合物(GFRP)复合材料制造飞机的结构和非结构部件，因为它们具有优越的强度重量比和卓越的耐腐蚀性。商用飞机的工作温度范围很宽，从-54°C到55°C。潜在的玻璃钢层压板在飞机运行过程中容易受到冲击，冲击时的温度决定了损伤和失效机制的性质。因此，目前的研究重点是研究航空GFRP复合材料在高空和低空作业中遇到的各种温度环境下的性能。采用s2 -玻璃纤维/ fm94 -环氧单向预浸料制备GFRP板材。在环境温度(25°C)、高温度(50、75、100°C)和低温度(-25、-55°C)以及不同的冲击能量(75、150、225 J)下进行了落锤冲击试验。每个测试场景的冲击参数，包括冲击载荷、挠度和能量吸收，也进行了检查。在Abaqus/Explicit中，建立了温度-位移耦合数值模型来预测应力和损伤的发生。根据实验结果，GFRP板在低温下比在其他温度下更硬，表现出更少的明显损伤(位移降低~ 15-34%)。此外，观察到高温下基体软化，在进入时损伤面积较大，但损伤不明显，能量吸收增加，而在低温下进入时发生半穿孔，损伤面积较小。实验数据与有限元数据之间存在很强的相关性，证实了有限元模型在未来不同温度下预测冲击损伤和挠度的能力。Full-color, Highly Bright and Stretchable Electroluminescent Device with Janus Colors Based on Photoluminescent Electrode for Wireless Dynamical DisplayZupeng Liu, Hao Yang, Haiyuan Yuan, Yuliang Cheng, Bingang Xu, Ming Xue, Titao Jingdoi:10.1016/j.compositesb.2024.111787基于光致发光电极的无线动态显示全彩色、高亮度、可拉伸双色电致发光器件Stretchable displays are essential for the upcoming era of flexible electronics as they are the foundation of interactive human–machine interface. To date, alternating current electroluminescent (ACEL) devices are regarded as one of the most practicable routes for stretchable displays but their colors are very limited for the demand of full-color displays. Herein, we developed an ACEL device with Janus and full color through photoluminescent electrodes. In the front of the devices, multiple colors are achieved, Red, Blue, Green, and Yellow, covering a 66% National Television System Committee color gamut. In the back, mixed lights of White, Purple, and Cyan color are obtained, enabling devices with Janus colors. The brightness enhancement of highly desirable white light achieves 4.4-fold, which is also one of the best performances. Our strategy exploits the indispensable electrode for ACEL and avoids structural changes, endowing the devices with a much better stretchability and brightness as compared to traditional methods. Moreover, our strategy is a general method that is applicable to different stretchable ACEL devices. A wearable device of 8*8 pixels is assembled and can dynamically display information from smart phones through Bluetooth in real time, laying a considerable advancement towards stretchable displays with full color.可拉伸显示器是即将到来的柔性电子时代必不可少的，因为它们是交互式人机界面的基础。迄今为止，交流电致发光(ACEL)器件被认为是可拉伸显示最可行的途径之一，但其颜色对于全彩显示的需求非常有限。在此，我们通过光致发光电极开发了具有双面和全彩的ACEL装置。在设备的前面，实现了多种颜色，红，蓝，绿，黄，覆盖66%的国家电视系统委员会色域。在背面，获得白色，紫色和青色的混合光，使设备具有双面神色。非常理想的白光亮度增强达到4.4倍，这也是最好的性能之一。我们的策略利用了ACEL不可缺少的电极，避免了结构变化，使器件具有比传统方法更好的拉伸性和亮度。此外，我们的策略是一种通用的方法，适用于不同的可拉伸ACEL设备。组装出8*8像素的可穿戴设备，通过蓝牙实时动态显示智能手机信息，向可拉伸全彩显示方向迈进了一大步。Composites Science and TechnologyDamage identification of plain-woven composites at T > Tg using AE: damage clustering and initiation detectionHao Lu, Tao Zheng, Li Zhang, Kai Huang, Xiaodong Liu, Xiaojian Han, Yue Wang, Licheng Guodoi:10.1016/j.compscitech.2024.110823 用声发射识别T > Tg平面编织复合材料的损伤:损伤聚类和起爆检测In this work, the damage modes and their initiation detections of plain-woven composites under tensile and compressive loads at T > Tg are investigated by conducting a comprehensive analysis of AE signals, including the feature selection, algorithm comparison and clustering validity. According to a newly proposed Pearson correlation coefficient cumulative criterion, the PF and PA are the most representative features of AE signals. A systematic comparison of K-Means, GMM and Hierarchical model, reveals that the Hierarchical model is the most suitable clustering algorithm for plain-woven composites at T > Tg. The cluster validity indexes combined with microscopic observations identify matrix cracking, interface debonding and fiber breakage as the three dominant damage modes, with PF ranges of [0-200 kHz], [200-350 kHz] and [350-600 kHz], respectively, and independent of different loading conditions. Three damage initiation criteria, sentry function, b-value and cumulative AE counts, are compared and the sentry function is determined to be optimal. The damage initiations of matrix cracking, interface debonding and fiber breakage within plain-woven composites at T > Tg can be effectively detected by AE.本文通过对声发射信号的综合分析，包括特征选择、算法比较和聚类有效性，研究了T > Tg的拉伸和压缩载荷作用下平纹编织复合材料的损伤模式及其起裂检测。根据新提出的Pearson相关系数累积准则，波峰和波峰是声发射信号最具代表性的特征。通过对K-Means、GMM和Hierarchical模型的系统比较，发现在T > Tg时，Hierarchical模型是最适合的聚类算法。结合微观观察，聚类有效性指标确定基体开裂、界面脱粘和纤维断裂是三种主要的损伤模式，其PF范围分别为[0 ~ 200 kHz]、[200 ~ 350 kHz]和[350 ~ 600 kHz]，且与不同加载条件无关。通过对哨兵函数、b值和累积声发射计数三种损伤起爆准则的比较，确定哨兵函数为最优。在T > Tg时，声发射可以有效地检测到复合材料内部基体开裂、界面剥离和纤维断裂的损伤起始。Liquid metal Induced segregated-like Electromagnetic Shielding composites with Excellent Photothermal conversion and Strain Sensing CapacitiesLijuan Qiu, Wanlin Han, Qinglong Yu, Yijun Liu, Baoshu Chen, Longfei Yidoi:10.1016/j.compscitech.2024.110825 具有优异光热转换和应变传感能力的液态金属诱导类偏析电磁屏蔽复合材料The development of multifunctional electromagnetic interference (EMI) shielding materials has garnered significant attention, yet achieving flexible composites that integrate EMI shielding, thermal conductivity, and other functionalities under low filler loading remains a challenge. This study presents a novel flexible composite with segregated structure prepared via a simple co-mixing and hot-pressing method. By selectively distributing conductive Liquid metal (LM) and Multi-wall carbon nanotube (CNT) on the surface of Polyurethane (TPU) particles, a continuous and compact conductive network is successfully constructed, enabling the attainment of a high EMI shielding effectiveness of 80.2 dB and a thermal conductivity of 4.8 W m-1 K-1 even at low LM loadings. Furthermore, the composite exhibits low-voltage-driven Joule heating performance, excellent photothermal conversion efficiency, and promising potential for wearable sensor applications. The combination of these outstanding properties highlights the great potential of LM-based composites for next-generation wearable devices.多功能电磁干扰(EMI)屏蔽材料的开发已经引起了极大的关注，然而，在低填料负载下实现集成EMI屏蔽、导热性和其他功能的柔性复合材料仍然是一个挑战。采用简单的共混热压法制备了一种具有分离结构的新型柔性复合材料。通过选择性地将导电液态金属(LM)和多壁碳纳米管(CNT)分布在聚氨酯(TPU)颗粒表面，成功构建了连续紧凑的导电网络，即使在低LM负载下，也能获得80.2 dB的高EMI屏蔽效能和4.8 W m-1 K-1的导热系数。此外，该复合材料具有低电压驱动的焦耳加热性能，出色的光热转换效率，在可穿戴传感器应用中具有广阔的潜力。这些卓越性能的结合凸显了lm基复合材料在下一代可穿戴设备中的巨大潜力。Lightweight and compressible PANI/Ti3C2Tx/EVA composite foam for tunable microwave absorptionZimo He, Yiyuan Shi, Huiya Wang, Yaofeng Zhudoi:10.1016/j.compscitech.2024.110826 轻质可压缩PANI/Ti3C2Tx/EVA复合泡沫可调微波吸收Dynamic deformation and absorbing regulation are still challenging for designing lightweight and high-efficiency microwave absorbing materials, which are of great indispensability to satisfy changeable and complex electromagnetic environments. Herein, a compressible composite foam with sea-island structure was prepared by loading porous polyaniline (PANI)/Ti3C2Tx composites on ethylene/vinyl acetate (EVA) skeleton via a thermally induced phase separation strategy. The composite foam exhibits a minimum reflection loss (RLmin) of –57.84 dB and an effective absorption bandwidth (EAB, RL ≤ −10 dB) of 1.86 GHz (8.2–10.05 GHz) at 3.4 mm. Notably, the microwave absorption (MA) performance can be precisely regulated by simply adjusting the compression ratio of composite foam. The RL peaks shift towards higher frequencies with increasing compression ratios, originating from changes in the internal conductive network. Even under 30 % compression strain, the composite foam still maintains RLmin of –21.53 dB and broadens EAB up to 2.71 GHz at 2.0 mm. This combination of compression capabilities and dynamically tunable MA performance may expand a novel approach to designing multifunctional polymer-based foam.动态变形和吸波调节仍是设计轻质高效微波吸波材料的挑战，对于满足多变复杂的电磁环境不可或缺。本文通过热诱导相分离策略，在乙烯/醋酸乙烯（EVA）骨架上负载多孔聚苯胺（PANI）/Ti3C2Tx复合材料，制备了具有海岛结构的可压缩复合泡沫。复合泡沫的最小反射损耗（RLmin）为 -57.84 dB，在 3.4 mm 时的有效吸收带宽（EAB，RL ≤ -10 dB）为 1.86 GHz（8.2-10.05 GHz）。值得注意的是，只需调整复合泡沫的压缩比，就能精确调节微波吸收（MA）性能。随着压缩比的增加，RL 峰值会向更高的频率移动，这源于内部导电网络的变化。即使在 30% 的压缩应变下，复合泡沫仍能保持 -21.53 dB 的 RLmin，并在 2.0 mm 时将 EAB 扩大到 2.71 GHz。这种压缩能力与动态可调 MA 性能的结合，为设计基于聚合物的多功能泡沫提供了一种新方法。来源：复合材料力学仿真Composites FEM
