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 2 篇Composite StructuresA mean field homogenization model for the mechanical response of ceramic matrix compositesKevin Spilker, Ricardo A. Lebensohn, George Jacobsen, Laurent Capolungodoi:10.1016/j.compstruct.2024.118630陶瓷基复合材料力学响应的平均场均匀化模型SiC/SiC composites offer exceptional mechanical stability at high temperatures and under irradiation. These ceramic matrix composites are therefore strong candidate materials for future nuclear energy applications. Their mechanical response, which exhibits pseudo-plasticity, is mediated by matrix cracking, fiber debonding, and fiber pull-out due to slip. This study introduces a mechanistic model for the behavior of unidirectionally reinforced SiC/SiC composites. Specifically a mean field homogenization approach is proposed to account for all deformation and degradation modes during mechanical deformation. The homogenization scheme relies on a Mori Tanaka method that is extended to consider the effects of the coating’s elasto-plastic response on the development of micromechanical fields. Further, the model proposed introduces a method to effectively account for the role of localized damage (i.e., cracks) on mechanical fields within both the fiber and the matrix. Upon validating the model against experimental data, the roles of interface sliding, coating dimensions and intrinsic elastic response, as well as of microstructure (e.g. porosity, fiber volume fraction) are discussed.SiC/SiC复合材料在高温和辐照下具有优异的机械稳定性。因此，这些陶瓷基复合材料是未来核能应用的强有力的候选材料。它们的力学响应表现为伪塑性，是由基体开裂、纤维脱粘和纤维因滑移而拉出介导的。介绍了单向增强SiC/SiC复合材料性能的机理模型。具体来说，提出了一种平均场均匀化方法来解释机械变形过程中的所有变形和退化模式。均匀化方案依赖于Mori Tanaka方法，该方法扩展到考虑涂层弹塑性响应对微力学场发展的影响。此外，所提出的模型引入了一种方法来有效地考虑纤维和基体内部的局部损伤（即裂纹）在力学场中的作用。根据实验数据验证了模型，讨论了界面滑动、涂层尺寸和固有弹性响应以及微观结构（如孔隙率、纤维体积分数）的作用。Mode I crack propagation in polydimethylsiloxane-short carbon fiber compositesNan Hou, Qiang Guo, Fahmi Zaïri, Ning Dingdoi:10.1016/j.compstruct.2024.118682聚二甲基硅氧烷-短碳纤维复合材料的I型裂纹扩展This paper presents a comprehensive analysis of reinforcement toughening and failure mechanisms in polydimethylsiloxane (PDMS)-carbon fiber (CF) composites employing an approach combining experiments and numerical simulations. Through a series of meticulously designed mechanical experiments, the behavior of the composite material under varying conditions is thoroughly examined. The introduction of CFs enhances the stiffness of the material while also leading to debonding and an increased Mullins effect. A constitutive model replicating the observed reinforcement and damage behavior is implemented. Our investigation extends to the analysis of crack growth through both numerical simulations and microscopic morphological examinations. A cohesive zone model is subsequently utilized to simulate crack propagation, providing enhanced understanding of the relationship between structural characteristics and mechanical behaviors. The process of crack propagation subjects the materials to cycles of loading and unloading, highlighted by the reinforcing action of CF pinning and stress transfer, alongside toughening mechanisms attributed to a variety of dissipative processes: interfacial debonding damage, energy loss due to CF pull-out, the Mullins effect, and viscous energy dissipation. This study elucidates the complex mechanical interplay within PDMS-CF composites and suggests pathways for their design optimization, significantly broadening their applicability in numerous domains.采用实验与数值模拟相结合的方法，对聚二甲基硅氧烷(PDMS)-碳纤维（CF）复合材料的增强增韧及失效机理进行了综合分析。通过一系列精心设计的力学实验，彻底检查了复合材料在不同条件下的行为。碳纤维的引入提高了材料的刚度，同时也导致了脱粘和增加的马林斯效应。一个本构模型复 制观察到的钢筋和损伤行为实现。我们的研究扩展到裂纹扩展的分析，通过数值模拟和微观形态检查。随后利用内聚区模型来模拟裂纹扩展，从而更好地理解结构特征与力学行为之间的关系。裂纹扩展过程使材料受到加载和卸载循环的影响，突出表现为CF钉钉和应力传递的增强作用，以及归因于各种耗散过程的增韧机制：界面脱粘损伤、CF拉出导致的能量损失、Mullins效应和粘性能量耗散。本研究阐明了PDMS-CF复合材料内部复杂的力学相互作用，并为其设计优化提供了途径，大大拓宽了其在许多领域的适用性。Identification of component material in-situ properties of C/SiC composites based on self-consistent clustering analysis and Bayesian methodBo Gao, Xinhang Dai, Hongyue Wang, Xinliang Zhao, Chenghai Xu, Qiang Yang, Songhe Mengdoi:10.1016/j.compstruct.2024.118686基于自一致聚类分析和贝叶斯方法的C/SiC复合材料原位性能识别In the paper, a method for identifying the mechanical properties of the in-situ component materials in carbon fiber reinforced silicon carbide ceramic matrix composites based on the macro mechanical test data is proposed. Firstly, the computation efficiency of considering damage behavior in the meso-mechanial model is improved through the self-consistent clustering analysis. Subsequently, sensitivity analysis is introduced in the parameter identification based on the Bayesian network to reduce the number of parameters to be identified simultaneously, thereby alleviating the ill-posedness of the inverse problem. Numerical and experimental cases were conducted to validate the proposed method. The maximum error of parameter identification is 6.0 % and the prediction error for strength is only 1.7 % in the numerical case with 5 % Gaussian noise. In the experimental case, the stress–strain curve calculated using the identified results shows good agreement with the experimental data. The prediction error for strength is only 2.2 %, while the maximum deviation between the identified results and the reference value in the literature can be up to 50 %, indicating the importance of obtaining the properties of component materials in-situ.本文提出了一种基于宏观力学试验数据的碳纤维增强碳化硅陶瓷基复合材料原位构件材料力学性能鉴定方法。首先，通过自洽聚类分析提高细观力学模型中考虑损伤行为的计算效率；随后，在基于贝叶斯网络的参数识别中引入灵敏度分析，减少了同时需要识别的参数数量，从而减轻了反问题的病态性。通过数值和实验验证了该方法的有效性。在高斯噪声为5 %的数值情况下，参数辨识的最大误差为6.0 %，强度预测误差仅为1.7 %。在实验情况下，利用识别结果计算的应力-应变曲线与实验数据吻合较好。强度预测误差仅为2.2 %，而识别结果与文献参考值的最大偏差可达50 %，说明原位获取构件材料性能的重要性。Composites Part A: Applied Science and ManufacturingReliable longitudinal electrical conductivity characterisation of unidirectional CFRP tapesY.M. Buser, E.T.M. Krämer, R. Akkerman, W.J.B. Grouvedoi:10.1016/j.compositesa.2024.108550单向CFRP胶带可靠的纵向导电性表征Induction welding is a promising assembly method for carbon fibre reinforced thermoplastic composites. In this process, an alternating electromagnetic field induces eddy currents in a composite susceptor. Accurate determination of the electrical conductivity of the carbon fibre network is essential for the development of physics-based simulations of the process. This work focuses on characterisation of the longitudinal electrical conductivity of unidirectionally reinforced paek using the six-probe method. Special attention is given to validating the boundary conditions and assumptions underlying the experimental procedure. The experimental results show that the longitudinal electrical conductivity consistently adheres to the rule of mixtures; nevertheless, achieving this finding proves sensitive to the care put into the procedural execution. Additionally, the study provides a valuable dataset for various commercially available tapes relevant to the aerospace industry.感应焊是一种很有前途的碳纤维增强热塑性复合材料组装方法。在这个过程中，交变电磁场在复合感受器中产生涡流。准确测定碳纤维网络的电导率对于开发基于物理的过程模拟至关重要。本工作的重点是利用六探针方法表征单向增强paek的纵向电导率。特别注意验证边界条件和假设的实验过程。实验结果表明：纵向电导率始终遵循混合规律；然而，实现这一发现证明对程序执行的谨慎是敏感的。此外，该研究还为与航空航天工业相关的各种商用磁带提供了有价值的数据集。Hierarchical hollow MnO/carbon fiber@WS2 composite material exhibits strong wideband electromagnetic wave attenuationXiaoxiao Zhao, Ying Huang, Huiyang Jiang, Xudong Liu, Xiaofang Ma, Panbo Liu, Meng Zongdoi:10.1016/j.compositesa.2024.108565 分层中空MnO/碳fiber@WS2复合材料表现出较强的宽带电磁波衰减Constructing multi-layer heterogeneous interfaces has been studied as one of the important means to optimize electromagnetic wave absorption performance. WS2, as a special layered material with high specific surface area and multiple anionic vacancies, although its multi-layered interface structure cannot meet the requirements of all absorbing materials, composite absorbers designed through composition and structure are undoubtedly not one of the strategies to improve absorption bandwidth. In this study, we utilized the defect rich characteristics of WS2 Nano flowers and designed a multi-layer core–shell MnO/CF@WS2 (H-MCW) hybrid materials using carbon fiber (CF) as a carrier to provide a carbon source. The core cavity of H-MCW is conducive to multiple scattering of electromagnetic waves, with a large number of defects leading to an increase in electrochemical active sites in the material, and enhanced dipoles helping to improve impedance matching. This work provides a new method for designing lightweight thin film absorbing materials.构建多层非均质界面是优化电磁波吸收性能的重要手段之一。WS2作为一种具有高比表面积和多个阴离子空位的特殊层状材料，虽然其多层界面结构不能满足所有吸波材料的要求，但通过成分和结构设计复合吸波材料无疑不是提高吸波带宽的策略之一。本研究利用WS2纳米花缺陷丰富的特点，设计了以碳纤维（CF）为载体提供碳源的多层核壳MnO/CF@WS2 （H-MCW）杂化材料。H-MCW的芯腔有利于电磁波的多次散射，大量的缺陷导致材料中电化学活性位点的增加，偶极子的增强有助于改善阻抗匹配。本工作为设计轻量化薄膜吸波材料提供了一种新的方法。Composites Part B: EngineeringTemperature and rate dependent shear characterization and modeling of spread-tow woven Flax/PP composite laminatesRamak Hossein Abadi, Kalliopi-Artemi Kalteremidou, Javane Karami, Danny Van Hemelrijckdoi:10.1016/j.compositesb.2024.111930拉伸-拖曳亚麻/PP复合层压板的温度和速率相关剪切特性和建模This paper investigates the in-plane shear behavior of spread-tow woven structured flax fiber-reinforced polypropylene composites, focusing on temperature and displacement rate effects. For this aim, the study includes bias-extension experiments to characterize the shear behavior of the material. Several experiments were conducted at different displacement rates and temperature levels. The temperature levels were chosen to encompass the material's behavior during solid and molten-state thermoforming, given the melting and decomposition temperatures acquired from differential scanning calorimetry and thermogravimetric analysis tests, respectively. A new fixture was designed and manufactured to allow pre-heating of the oven and rapid placement of the samples, which in turn, prevents their degradation for the time duration required to reach a uniform temperature distribution in the oven. During the experiments, the 3D digital image correlation technique accurately measured local deformations and strains on the specimen's surface under varying conditions. Further, a finite element model is developed, incorporating a fiber reorientation algorithm with a hypo-elastic shear model to simulate the material's temperature and rate-dependent behavior. The finite element shear angle distributions, as well as the shear angle-force and shear angle-displacement curves, are compared with the Digital Image Correlation (DIC) data and load measurements for different test conditions, showing good agreement between the numerical and experimental approaches.本文研究了展拖编织结构亚麻纤维增强聚丙烯复合材料的面内剪切性能，重点研究了温度和位移速率的影响。为此，研究包括偏伸实验来表征材料的剪切行为。在不同的驱替速率和温度水平下进行了多项实验。根据差示扫描量热法和热重分析测试分别获得的熔化和分解温度，所选择的温度水平涵盖了材料在固态和熔融状态热成型过程中的行为。设计和制造了一种新的夹具，以允许烤箱预热和快速放置样品，这反过来又可以防止它们在达到烤箱均匀温度分布所需的时间内降解。在实验过程中，三维数字图像相关技术精确测量了不同条件下试件表面的局部变形和应变。此外，开发了一个有限元模型，结合纤维定向算法和亚弹性剪切模型来模拟材料的温度和速率依赖行为。将有限元剪切角分布以及剪切角-力和剪切角-位移曲线与不同试验条件下的数字图像相关（DIC）数据和载荷测量结果进行了比较，结果表明数值方法与实验方法吻合较好。Composites Science and TechnologyFabrication and mechanical properties of CFRP honeycomb cylinder based on the transforming from the flat honeycombsZhibin Li, Pengcheng Xue, Jian Xiongdoi:10.1016/j.compscitech.2024.110948 基于平板蜂窝改造的CFRP蜂窝筒的制造及其力学性能Nature has long inspired the design of high-performance structures, offering profound insights into engineering innovations through intricate biological architectures. The rational design of composite curved components is crucial for the lightweight construction of aerospace structures. In the transition from planar constructs to curved components, any mismatch in form can induce high stress, potentially leading to structural compromise or failure. Drawing inspiration from the water lily, a rational design and fabrication approach for cylindrical surface structures is proposed, transitioning from planar to curved surfaces. The adaptation of zero Poisson's ratio honeycomb to cylindrical surface is verified by experiments and simulations. The mismatch relationship between them would lead to the damage failure of the honeycomb. In view of this, the honeycomb sandwich cylinder commonly used in aerospace is fabricated by the proposed method. Using this approach, a honeycomb sandwich cylinder—commonly utilized in aerospace applications—was fabricated. Theoretical predictions and experimental characterizations were conducted to analyze failure modes under axial compression. This led to the creation of a failure mechanism map for the honeycomb cylinder. Load-mass efficiency analysis revealed that face-crushing failure provides high bearing efficiency. Additionally, the effects of facesheet thickness, along with a comparison of failure modes and imperfection sensitivity between single and sandwich cylinders, were explored. The results indicate that the sandwich cylinder exhibits a higher specific load-bearing capacity and lower imperfection sensitivity compared to the single cylinder.长期以来，大自然激发了高性能结构的设计灵感，通过复杂的生物结构为工程创新提供了深刻的见解。复合材料曲面构件的合理设计是航空航天结构轻量化的关键。在从平面结构到弯曲构件的过渡过程中，任何形式的不匹配都可能引起高应力，从而可能导致结构妥协或失效。从睡莲中获得灵感，提出了一种由平面过渡到曲面的圆柱形表面结构的合理设计和制造方法。通过实验和仿真验证了零泊松比蜂窝对圆柱表面的适应性。它们之间的不匹配关系将导致蜂窝的破坏破坏。为此，采用该方法制备了航空航天中常用的蜂窝夹层筒体。利用这种方法，制造了一个蜂窝夹层圆柱体-通常用于航空航天应用。进行了理论预测和实验表征，分析了轴压作用下的破坏模式。这导致了蜂窝圆柱体失效机理图的创建。载荷-质量效率分析表明，面压破坏提供了较高的承载效率。此外，还探讨了面板厚度的影响，以及单柱和夹层柱之间的失效模式和缺陷灵敏度的比较。结果表明：夹层筒体比单一筒体具有更高的比承载能力和更低的缺陷敏感性；Improving the high-voltage insulation properties of polypropylene by introducing trace addition of polyvinylidene fluoride: An experimental and simulation studyOhuk Lee, Do-Kyun Kim, Hana Kim, Seong Hwan Lee, Taehoon Kwon, Ik-Su Kwon, Keisuke Shinozaki, Masayuki Hikita, Jin Hong Lee, Dae Ho Lee, Min Hee Kim, Masahiro Kozako, Seunggun Yudoi:10.1016/j.compscitech.2024.110939 引入微量聚偏氟乙烯改善聚丙烯高压绝缘性能的实验与模拟研究Various additives ranging from inorganic nanoparticles to organic additives have been suggested to improve the insulation performance of polymeric materials for high-voltage engineering applications. Herein, a simple method for doping fluorine into a polypropylene (PP) matrix was presented by melt-blending of isotactic PP (iPP) with a small amount of polyvinylidene fluoride (PVDF) as a thermoplastic voltage stabilizer (TVS). During melt-mixing, the PVDF TVS, which is immiscible with PP, is gradually split into smaller domains within the iPP matrix and finely distributed, especially at a low PVDF content. The direct current (DC) breakdown strength (BDS) values of the PVDF-doped iPP increased by 110% and 149% at 25 and 110 °C, respectively, compared to those of the pristine PP, while its dielectric permittivity and loss tangent values remained nearly similar to those of iPP at wide temperature between 25 and 140 °C and frequency range between 1 Hz and 10 MHz. Quantum chemical simulation results reveal that a small amount of PVDF with high dipole moment introduces deep trap sites within the polymer matrix, which contribute for increasing BDS of iPP. Also, the PP with a small amount of PVDF dopants below 1.0 phr exhibited no any decrease in the tensile strength and elongation at break values. Therefore, the PVDF-doped iPP is anticipated as a potential candidate as high-performance high-voltage insulation materials for next-generation insulation applications.从无机纳米颗粒到有机添加剂的各种添加剂已被建议用于改善高压工程应用的聚合物材料的绝缘性能。本文提出了一种将氟掺杂到聚丙烯（PP）基体中的简单方法，即将等规聚丙烯（iPP）与少量聚偏氟乙烯（PVDF）熔融共混作为热塑性稳压器（TVS）。在熔融混合过程中，与PP不相混的PVDF tv在iPP基体中逐渐分裂成更小的区域并精细分布，特别是在PVDF含量低的情况下。在25°C和110°C下，掺pvdf的iPP的直流击穿强度（BDS）值分别比未掺pvdf的iPP提高了110%和149%，而在25 ~ 140°C的宽温度和1 Hz ~ 10 MHz的频率范围内，其介电常数和损耗正切值与未掺pvdf的iPP保持接近。量子化学模拟结果表明，少量具有高偶极矩的PVDF在聚合物基体中引入了深阱位点，这有助于提高iPP的BDS。此外，在1.0 phr以下，添加少量PVDF的PP的拉伸强度和断裂伸长率没有下降。因此，pvdf掺杂iPP有望成为下一代高性能高压绝缘材料的潜在候选材料。来源：复合材料力学仿真Composites FEM
