今日更新：Composite Structures 2 篇，Composites Part A: Applied Science and Manufacturing 3 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 4 篇Composite StructuresCreep resistance enhancement and modeling of 3D printed Polyetherimide/carbon black compositesMerve Karabal, Alptekin Yıldızdoi:10.1016/j.compstruct.2024.1183983D打印聚醚酰亚胺/炭黑复合材料的抗蠕变增强和建模This study investigates the potential of carbon black (CB) reinforcement to enhance the mechanical properties of high-performance Polyetherimide (PEI) compromised by Material Extrusion (MEX), making them comparable to those produced by conventional methods. PEI filaments with varying CB fractions (5 – 20 wt%) were produced, and creep test specimens were fabricated via MEX. A neat PEI hot-pressed specimen was also manufactured for comparison. The results demonstrated a 7% increase in ultimate tensile strength (UTS), alongside 14% decrement in creep strain with 5 wt% CB reinforcement, approaching the performance of conventionally manufactured neat PEI. Creep behavior was modeled using Burgers, Kelvin–Voigt, and Findley models, with Findley’s model proving effective in capturing instantaneous strain. Additionally, the Time-Temperature Superposition Principle (TTSP) was applied to develop creep master curves up to 10^9s. This study highlights the potential of CB as a cost-effective reinforcement material to improve the mechanical properties of 3D-printed high-performance polymers.本研究探讨了碳黑（CB）增强材料在提高高性能聚醚酰亚胺（PEI）机械性能方面的潜力，这种材料通过材料挤压（MEX）制成，可与传统方法制成的材料相媲美。生产出了不同 CB 分数（5 - 20 wt%）的 PEI 长丝，并通过 MEX 制作了蠕变测试试样。同时还制作了一个纯 PEI 热压试样进行比较。结果表明，5 wt% CB 增强材料的极限拉伸强度 (UTS) 提高了 7%，蠕变应变降低了 14%，接近传统制造的纯 PEI 的性能。蠕变行为是通过伯格斯模型、开尔文-伏依格特模型和芬德雷模型来模拟的，其中芬德雷模型在捕捉瞬时应变方面被证明是有效的。此外，还应用时间-温度叠加原理 (TTSP) 开发了蠕变主曲线，最高可达 10^9s。这项研究凸显了 CB 作为一种具有成本效益的增强材料在改善 3D 打印高性能聚合物机械性能方面的潜力。Effect of the level of anisotropy on the macroscopic failure of notched thin-ply laminatesAnatoli Mitrou, Albertino Arteiro, José Reinoso, Pedro P. Camanhodoi:10.1016/j.compstruct.2024.118407各向异性水平对缺口薄板宏观破坏的影响This work presents a detailed experimental study conducted for a range of different lay-ups using thin-ply carbon fiber reinforced polymer (CFRP) laminates. The selection of the laminates was performed relying on their level of anisotropy. The laminates vary from a quasi-isotropic (QI) laminate, which is weakly anisotropic, to a cross-ply (CP) laminate, which is strongly anisotropic. The laminates were tested in on-axis and off-axis open hole tension (OHT). The main objective was to observe the effect of the level of anisotropy of the laminate on the macroscopic failure and observed failure patterns. It is shown that, contrary to most existing observations so far, depending on the lay-up and consequently its level of anisotropy, open-hole, quasi-homogeneous thin-ply laminates do not necessarily exhibit a fiber dominated failure mode, but could develop sub-critical damage mechanisms in a large extent prior to ultimate failure, reminiscent of what is observed for standard-ply CFRP laminates.这项工作提出了一个详细的实验研究进行了一系列不同的铺装使用薄层碳纤维增强聚合物(CFRP)层压板。层压板的选择取决于它们的各向异性水平。层压板从弱各向异性的准各向同性(QI)层压板到强各向异性的交叉层(CP)层压板不等。对层合板进行了轴向和离轴裸眼拉伸(OHT)测试。主要目的是观察层压材料各向异性水平对宏观破坏和观察到的破坏模式的影响。研究表明，与大多数现有的观察结果相反，到目前为止，取决于铺层及其各向异性水平，开孔、准均匀薄层层压板不一定表现出纤维主导的破坏模式，但在最终破坏之前，可能在很大程度上发展亚临界损伤机制，让人想起标准层CFRP层压板所观察到的情况。Composites Part A: Applied Science and ManufacturingBurst pressure prediction of cord-rubber composite structures using global-local nonlinear finite element analysisAhaan Bhosale, Rob Barendse, Boyang Chen, J.M.J.F. van Campendoi:10.1016/j.compositesa.2024.108361 基于全局-局部非线性有限元分析的索-胶复合结构爆破压力预测This study aims to develop a model to predict the burst pressure of a dry filament wound cord-rubber composite pressure vessel under hydrostatic internal pressurization using a submodelling based global-local FEA model. The model links the global displacements of a rebar-based model to obtain the local deformation state in a single rhomboidal representative volume. Emphasis is placed on capturing the local stress concentrations in the fibers due to the unique filament winding mosaic pattern. Fiber damage is included in the local model using a maximum principle strain criteria. Verification of the created model is done experimentally on industrially manufactured burst-test specimens. Measurements for displacement during the experiments are taken photographically, while the burst pressure is captured using a pressure transducer. The final error between the burst pressure of the samples and the experimental demonstrators is approximately 6.5%, a marked improvement over conventional models with truss and rebar elements as fibers.采用基于子模型的全局-局部有限元分析方法，建立了干丝缠绕绳-橡胶复合材料压力容器在静水压下的破裂压力预测模型。该模型将钢筋模型的整体 位移联系起来，在单个菱形代表体中获得局部变形状态。由于独特的长丝缠绕马赛克图案，重点放在捕获纤维中的局部应力集中。采用最大主应变准则将纤维损伤纳入局部模型。在工业生产的爆炸试验试样上对所建立的模型进行了实验验证。在实验过程中，位移测量是通过摄影进行的，而爆破压力是通过压力传感器捕获的。试样的破裂压力与实验模型之间的最终误差约为6.5%，与以桁架和钢筋为纤维的传统模型相比有显著改善。An integrated approach to analyzing matrix-crack-induced stiffness degradation and medium leakage in linerless composite vesselsHaitao Zhao, Mingqing Yuan, Yahui Peng, Xiaochu Gao, Li Tian, Boming Zhang, Chengcheng Zhang, Ji’an Chendoi:10.1016/j.compositesa.2024.108364无衬底复合材料容器中基体裂纹引起的刚度退化和介质泄漏的综合分析方法This paper proposes an integrated analysis method for linerless composite vessels considering matrix-crack-induced stiffness degradation and permeation. Stiffness degradation models are obtained using machine learning regression, the data sets of which consist of finite element analysis (FEA) results and virtual samples. Then, the effective leakage conductance is obtained by using the linear elastic fracture mechanics and the micro-cracking leakage mechanism. The proposed integrated method is applied to analyze vessel structures designed by the grid theory, which has variable ply thicknesses and layup angles. Simulation results show that whether the structure at cryogenic temperature cracks and leaks more easily depends on its dimensions and stacking sequences.本文提出了一种考虑基体裂纹引起的刚度退化和渗透的无衬底复合材料容器综合分析方法。采用机器学习回归方法建立了刚度退化模型，该模型的数据集由有限元分析结果和虚拟样本组成。然后，利用线弹性断裂力学和微裂纹泄漏机理得到有效泄漏电导。将该方法应用于网格理论设计的具有变层厚和变层角的船舶结构的分析。仿真结果表明，结构在低温下是否更容易开裂和泄漏取决于其尺寸和堆叠顺序。Damage and failure mechanisms of hybrid carbon fiber and steel fiber reinforced polymer compositesJan Rehra, Julia Jungbluth, Bilal Katri, Sebastian Schmeer, Martin Gurka, Frank Balle, Ulf P. Breuerdoi:10.1016/j.compositesa.2024.108366混杂碳纤维与钢纤维增强聚合物复合材料的损伤破坏机理Fiber-reinforced plastics (FRPs) are widely used due to their superior properties but often suffer from brittle failure and poor structural integrity under impact loads. Metal fiber hybrids (MFH) offer a solution, but understanding their structure–property relationships remains challenging. This research provides a comprehensive mechanical characterization of a stainless steel-carbon fiber hybrid (SCFRP) embedded in epoxy resin, with a particular focus on the failure mechanisms and their influences. Therefore, the mechanical properties of the material, as well as the propagation and damage of the fracture, are investigated. In addition, three main failure mechanisms are identified and analyzed. The failure mode of a SCFRP laminate can be influenced by its composition, architecture, and specimen size and result from a combination of the blast effect of the brittle failing carbon fibers, the magnitude of the associated damage, and the movement of the fracture gap formation initiated by the carbon fiber failure.纤维增强塑料(frp)由于其优越的性能而被广泛使用，但在冲击载荷下往往存在脆性破坏和结构完整性差的问题。金属纤维混合材料(MFH)提供了一种解决方案，但了解它们的结构-性能关系仍然具有挑战性。本研究提供了不锈钢-碳纤维复合材料(SCFRP)在环氧树脂中的综合力学特性，特别关注其失效机制及其影响。因此，研究了材料的力学性能以及断口的扩展和损伤。此外，还对三种主要失效机制进行了识别和分析。SCFRP层合板的破坏模式受其成分、结构和试样尺寸的影响，并受脆性碳纤维破坏的爆炸效应、相关损伤的大小和碳纤维破坏引发的断裂间隙形成的运动的综合影响。Composites Part B: EngineeringInterlayer Enhancement of 3D Printed CF/PLA Composites via Localized Microwave Welding and Annealing-Induced CrystallizationHongfu Li, Yuxi Mu, Qi Wang, Diandian Cai, Yuan Zhang, Yu Luo, Jiang Liu, Jintong Liu, Kangmin Niu, Ying Wu, Yuzhan Li, Naisheng Jiangdoi:10.1016/j.compositesb.2024.111737 基于局部微波焊接和退火诱导结晶的3D打印CF/PLA复合材料层间增强研究Interlayer defects and insufficient diffusion are detrimental to the structural integrity of 3D printed composites. This study introduces a facile approach to enhance the interlayer adhesion and structural integrity of 3D printed carbon fiber/polylactic acid (CF/PLA) composites, utilizing graphene-coated CF/PLA filaments for localized microwave welding and annealing-induced crystallization. This method promotes localized PLA melting at the interlayer interfaces, facilitating polymer diffusion and transcrystallization, which are crucial for effective interlayer repair and enhancement. The unique microwave dissipation properties of graphene ensure selective heating at the interlayer interfaces without largely affecting the intralayer CF, which is crucial for maintaining the overall structural integrity. Combining microwave welding with post-annealing treatment promotes transcrystalline growth at interlayer interfaces, which results in a 26.4% increase in 90° tensile strength of the 3D printed CF/PLA composites, demonstrating the effectiveness of our approach. These findings provide new insights into strategies for enhancing the mechanical properties of 3D printed carbon fiber thermoplastic composites through precise interlayer enhancement and interfacial defect repair.层间缺陷和扩散不足会影响3D打印复合材料的结构完整性。本研究介绍了一种简单的方法来增强3D打印碳纤维/聚乳酸(CF/PLA)复合材料的层间附着力和结构完整性，利用石墨烯涂层CF/PLA长丝进行局部微波焊接和退火诱导结晶。该方法促进了PLA在层间界面的局部熔化，促进了聚合物的扩散和转结晶，这是有效修复和增强层间的关键。石墨烯独特的微波耗散特性确保了层间界面的选择性加热，而不会对层内CF产生很大影响，这对于保持整体结构完整性至关重要。结合微波焊接和后退火处理促进了层间界面的跨晶生长，使3D打印的CF/PLA复合材料的90°拉伸强度提高了26.4%，证明了我们方法的有效性。这些发现为通过精确的层间增强和界面缺陷修复来增强3D打印碳纤维热塑性复合材料的机械性能提供了新的见解。Composites Science and TechnologyMultifunctional Hierarchical Electronic Skins: Unveiling Self-Repairing Mechanisms and Advancements in Sensing and Shielding PerformanceMuchao Qu, Linzhi Hu, Shunyin Wang, Hongji Chen, Guanda Yang, Dirk W. Schubert, Ri Chen, Fritjof Nilsson, Lei Handoi:10.1016/j.compscitech.2024.110769 多功能分层电子皮肤:揭示自我修复机制和传感和屏蔽性能的进展In light of advancements in electronic skins (E-skins), their application in extreme environments poses significant challenges. Inspired by real human skin, we have developed a hierarchical structured electronic skin that utilizes flexible carbon fiber fabric as a framework. Copper nanoflakes and embedded sensors function as the neural layer, while Ethylene Vinyl Acetate acts as the dermal layer, and Polytetrafluoroethylene is employed as the epidermal layer. The reported E-skin demonstrates outstanding flexibility, excellent heat resistance, robust mechanical properties (fracture strength of 1600 MPa, Young's modulus approximately 3.8 GPa), exceptional bending /compression strain performance, excellent hydrophobicity (water contact angle of 120°), effective electromagnetic shielding performance (approximately 45dB total shielding effectiveness for X-band), and electromagnetic wave absorption capability. Additionally, this E-skin possesses self-healing properties, capable of restoring to its original hydrophobic state within 30 seconds under a 9V voltage through the Joule heating effect, complemented by corresponding theoretical and mathematical modeling. This E-skin introduces a novel, environmentally friendly, and operationally simple strategy for enhancing the extreme environment resistance and durability of flexible devices.鉴于电子皮肤(e -skin)的进步，它们在极端环境中的应用提出了重大挑战。受真实人体皮肤的启发，我们开发了一种分层结构的电子皮肤，利用柔性碳纤维织物作为框架。铜纳米片和嵌入式传感器作为神经层，乙烯醋酸乙烯作为真皮层，聚四氟乙烯作为表皮层。所报道的E-skin具有出色的柔韧性、优异的耐热性、强大的机械性能(断裂强度为1600 MPa，杨氏模量约为3.8 GPa)、优异的弯曲/压缩应变性能、优异的疏水性(水接触角为120°)、有效的电磁屏蔽性能(x波段的总屏蔽效率约为45dB)和电磁波吸收能力。此外，该E-skin具有自愈特性，能够在9V电压下通过焦耳热效应在30秒内恢复到原来的疏水状态，并辅以相应的理论和数学模型。这种E-skin引入了一种新颖、环保、操作简单的策略，以增强柔性设备的极端环境抗性和耐用性。Stiffness-Switchable Hydrogel Composite for Transformable Exo-SuitYu Zhu, Meng-Ting Xu, Zhen-Hua Tang, Feng Chen, De-Yang Wang, Yuan-Qing Li, Shao-Yun Fudoi:10.1016/j.compscitech.2024.110763 可变形宇航服的刚度可切换水凝胶复合材料Transformable exo-suits, which are soft and wearable under normal conditions and could increase stiffness dramatically on demand, are significant in personal protection and robotics and also a dream of science-fiction fans. Herein, an ideal candidate material based on a carbon fabric reinforced thermal-hardening hydrogel (CFRTH) composite is proposed for developing transformable exo-suits. The introduction of carbon fabric significantly enhances the mechanical performance of thermal-hardening hydrogel, and empowers the CFRTH composite with an active, rapid and repeatable stiffness switchability. At ambient temperature, the CFRTH composite developed is soft and wearable with excellent flexibility and shape adaptability, while the composite becomes hard and rigid instantaneously as temperature rises. The flexural modulus of the CFRTH composite increases from 2.3 MPa to 539.7 MPa (about 232 times) by applying an electro-thermal stimulus, which endows the composite with good energy absorption/dissipation performance. Compared with the untransformed CFRTH composite, the transformed CFRTH composite under the electro-thermal stimulus exhibits 200% improvement in the peak force attenuation ratio under dropping ball test, 137% enhancement in withstanding puncture energy under penetration test, and 6 to 1 layer penetration depth reduction under knife stab. Finally, the transformable CFRTH composite demonstrates a high effectiveness in egg and glass protection from the impact of steel ball. This study offers a novel and versatile strategy for developing transformable exo-suits which have wearable conformability under normal circumstances and exhibit enhanced stiffness and impact protection performance on-demand through an electro-thermal stimulus.可变形的外服在正常条件下柔软可穿戴，并可根据需要大幅增加硬度，在个人防护和机器人领域具有重要意义，也是科幻爱好者的梦想。本文提出了一种基于碳织物增强热硬化水凝胶(CFRTH)复合材料的理想候选材料，用于开发可变形的外露服。碳织物的引入显著提高了热硬化水凝胶的机械性能，并使CFRTH复合材料具有主动、快速和可重复的刚度切换性。在室温下，CFRTH复合材料柔软耐磨，具有良好的柔韧性和形状适应性，但随着温度的升高，复合材料瞬间变硬变刚性。经电热刺 激后，CFRTH复合材料的抗弯模量由2.3 MPa提高到539.7 MPa(约232倍)，具有良好的吸耗能性能。与未转化CFRTH复合材料相比，经热处理后的CFRTH复合材料在落球试验下的峰值力衰减比提高了200%，在侵彻试验下的抗穿刺能量提高了137%，在刀刺作用下的侵彻深度降低了6∶1层。最后，可变形CFRTH复合材料在钢球冲击下对鸡蛋和玻璃的保护效果非常好。这项研究提供了一种新颖和通用的策略来开发可变形的外骨骼服，这种外骨骼服在正常情况下具有可穿戴性，并通过电热刺 激显示出增强的刚度和冲击保护性能。A Multifunctional Heterogeneous Structure Inspired by Shell Brick-Mud Structure: Balancing Noise Reduction and Mechanical PerformanceZhenglei Yu, Lixin Chen, Chaolei Zhang, Haojie Chi, Binkai Guo, Yanan Yang, Ruiyao Liu, Renlong Xin, Ping Liang, Zezhou Xu, Yunting Guo, Zhihui Zhang, Luquan Ren, Chunling Maodoi:10.1016/j.compscitech.2024.110765 受壳砖泥结构启发的多功能异质结构:平衡降噪与力学性能Electric armoured vehicles, which are crucial for strategic operations, must possess superior mechanical properties and noise reduction to maintain normal functionality. However, achieving high energy absorption and noise reduction performance simultaneously is challenging with a single uniform material or structure. This study introduces heterogeneous structures with metal lattice skeletons filled with polymer materials. The skeleton, known as the bionic mantis shrimp structure (BMS), is filled with polyurethane and epoxy. Impedance tube experiments revealed that the sound absorption coefficients of Heterostructure-polyurethane foam (HS-PU) and Heterostructure-epoxy (HS-EP) are significantly higher than BMS. HS-PU achieved an average sound insulation of 33.6 dB, marking a 739% improvement over BMS. Compression tests show that polymer filling can inhibit the destructive collapse of BMS and enhance its mechanical performance. HS-EP exhibits specific strength and specific energy absorption values of 57 MPa/(g·cm-3) and 30.75 J/g, respectively, representing an increase of 67.6% and 315% compared to BMS. Additionally, as the volume fraction of BMS increased in the heterogeneous structure, the elastic modulus and compressive strength increase while the specific energy absorption decreased. This research suggest that the design of metal/polymer heterogeneous structures offers a promising approach for developing high-strength and noise-reducing protective structures.电动装甲车对战略作战至关重要，必须具有卓越的机械性能和降噪能力，以保持正常的功能。然而，用单一的均匀材料或结构同时实现高能量吸收和降噪性能是具有挑战性的。本研究引入了金属晶格骨架填充高分子材料的非均相结构。这种被称为仿生螳螂虾结构(BMS)的骨架由聚氨酯和环氧树脂填充。阻抗管实验表明，异质结构聚氨酯泡沫(HS-PU)和异质结构环氧树脂(HS-EP)的吸声系数显著高于BMS。HS-PU实现了33.6 dB的平均隔声，比BMS提高了739%。压缩试验表明，聚合物填充可以抑制BMS的破坏性坍塌，提高其力学性能。HS-EP的比强度和比能吸收值分别为57 MPa/(g·cm-3)和30.75 J/g，比BMS分别提高了67.6%和315%。此外，随着BMS在非均相结构中的体积分数的增加，弹性模量和抗压强度增加，而比能吸收降低。该研究表明，金属/聚合物非均相结构的设计为开发高强度、低噪声的防护结构提供了一条有前途的途径。Highly Durable Hollow Sandwich MXene/h-AgNWs/ANF Composite Films for Exceptional Electromagnetic Interference Shielding PerformanceFan Xie, Qiaoling Liu, Xiyi Dai, Haitao Wei, Zhaoqing Ludoi:10.1016/j.compscitech.2024.110766 高度耐用的中空夹层MXene/h-AgNWs/ANF复合薄膜具有卓越的电磁干扰屏蔽性能Multi-functional electromagnetic interference (EMI) shielding materials are crucial for advanced electronic devices, requiring low thickness, exceptional shielding performance, and stability, especially in extreme conditions. In this study, the hollow sandwich MXene/h-AgNWs/ANF (AMAgMA) composite films were fabricated via template sacrificing method and layer-by-layer vacuum assisted filtration. Specifically, the hollow MXene was created using PMMA as the template, together with AgNWs for the conductive layer, while ANF provided stability and high temperature resistance as the protective layer. The optimized EMI shielding efficiency (SE) reached 88.2 dB for a film thickness of 93 μm, with an SSE/t value of 18160 dB·cm2·g–1, which was attributed to the hollow structure and continuous double conductive network design. Remarkably, EMI SE of the films maintained even after 70 days of exposure to oxidation, acid, alkali, salt, and ultrasonic treatment thanks to the sandwich design. Additionally, the composite films displayed excellent heat transfer and thermal stability (530 oC), alongside notable flame retardancy and self-extinguishing properties. The superior EMI shielding performance and stability in extreme environments suggest a promising application potential in advanced electronics.多功能电磁干扰(EMI)屏蔽材料对于先进的电子设备至关重要，它要求低厚度、卓越的屏蔽性能和稳定性，特别是在极端条件下。本研究采用模板牺牲法和逐层真空辅助过滤法制备了中空夹层MXene/h-AgNWs/ANF (AMAgMA)复合薄膜。具体来说，中空MXene是用PMMA作为模板，用AgNWs作为导电层，而ANF作为保护层提供稳定性和耐高温性。当膜厚为93 μm时，优化后的电磁干扰屏蔽效率SE达到88.2 dB, SSE/t值为18160 dB·cm2·g-1，这主要归功于中空结构和连续双导电网络设计。值得注意的是，由于夹层设计，即使经过70天的氧化、酸、碱、盐和超声波处理，薄膜的EMI SE仍然保持不变。此外，复合膜表现出优异的传热性能和热稳定性(530℃)，以及显著的阻燃性和自熄性。优越的电磁干扰屏蔽性能和在极端环境下的稳定性表明其在先进电子领域具有广阔的应用潜力。来源：复合材料力学仿真Composites FEM
