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【新文速递】2023年11月30日复合材料SCI期刊最新文章

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今日更新:Composite Structures 2 篇

Composite Structures

A review on bistable composite laminates for aerospace applications

Diego Magela Lemos, Flávio D. Marques, António J.M. Ferreira

doi:10.1016/j.compstruct.2023.117756

航空航天用双稳态复合材料层压板综述

Bistable laminates have attracted considerable interest among researchers as prospective candidates for delivering exceptional performance within the domain of morphing structures. These laminates exhibit a distinctive characteristic of featuring two stable states, sustaining their configuration until the application of a critical force that triggers a transition to their second stable position. Before discussing the practical applications involving bistable composite laminates, this paper presents analytical modeling for predicting the room-temperature shape and simulating the snap-through phenomena. The main aspects of the room-temperature shape simulation are discussed, and various snap-through triggering methods are shown. At this point, the paper focuses on a comparative analysis of numerical predictions in contrast to experimental data aimed at discerning the reliability of existing models. Furthermore, this paper not only elucidates existing challenges but also delineates potential avenues for future research. As the investigation into bistable composites progresses from comprehending intrinsic phenomena to practical, real-world applications, this study outlines both the present and potential future research concerning bistable composite laminates.

双稳态层压板作为可在变形结构领域提供卓越性能的潜在候选材料,引起了研究人员的极大兴趣。这些层压板具有两个稳定状态的显著特点,在施加临界力触发向第二个稳定位置过渡之前,一直保持其配置。在讨论涉及双稳态复合材料层压板的实际应用之前,本文介绍了预测室温形状和模拟快穿现象的分析模型。本文讨论了室温形状模拟的主要方面,并展示了各种快穿触发方法。在此基础上,本文重点对数值预测与实验数据进行了对比分析,旨在辨别现有模型的可靠性。此外,本文不仅阐明了现有的挑战,还划定了未来研究的潜在途径。随着对双稳态复合材料的研究从理解其本质现象发展到实际应用,本研究概述了有关双稳态复合材料层压板的现有研究和未来潜在研究。


Phase field-based cohesive zone approach to model delamination in fiber-reinforced polymer composites

Akash kumar, Trisha Sain

doi:10.1016/j.compstruct.2023.117751

基于相场的内聚区方法为纤维增强聚合物复合材料中的分层建模

In the present work, a unified phase field-based cohesive zone model (PF-CZM) has been utilized to predict bulk fracture and most importantly interfacial delamination in carbon fiber-reinforced polymer composites (CFRP). The formulation is based on the classical phase-field approach of energy minimization, with a rational degradation function and a polynomial-type crack geometric function. Incorporation of those provides the PF theory to integrate various traction-separation behaviors by choosing optimal constitutive functions and makes the theory capable of predicting the quasi-brittle type of fracture. Since the interfacial delamination in composites occurs either due to adhesive failure or decohesion between stacked lamina, the PF-CZM model is used to predict such failure by exploiting the cohesive zone flavor of the model. Further, the model inherently incorporates the strength of the material without any additional calibration. Various standard simulations are performed considering CFRP geometry where delaminations due to adhesive failure or interface decohesion occur in a mode-I and mode-II fashion. The model is observed to predict mode-I and mode-II separation accurately. To test the accuracy of the model an experimental validation is also performed. In addition to the delamination, open hole tension (OHT) simulations of CFRP lamina for different fiber orientations are considered to validate the anisotropic crack growth predictions, and the results are compared with experiments.

本研究利用基于相场的内聚区统一模型(PF-CZM)来预测碳纤维增强聚合物复合材料(CFRP)的体断裂,最重要的是界面分层。该模型以能量最小化的经典相场方法为基础,具有合理的退化函数和多项式型裂纹几何函数。这些因素的加入为 PF 理论提供了通过选择最佳构成函数来整合各种牵引分离行为的能力,并使该理论能够预测准脆性断裂类型。由于复合材料中的界面分层要么是由于粘合破坏,要么是由于叠层之间的脱粘,因此 PF-CZM 模型利用模型的内聚区特性来预测这种破坏。此外,该模型本身就包含了材料强度,无需额外校准。考虑到 CFRP 的几何形状,我们进行了各种标准模拟,在这些几何形状中,由于粘合剂失效或界面脱粘而导致的分层以模式 I 和模式 II 的方式发生。据观察,该模型能准确预测模式 I 和模式 II 分离。为了测试模型的准确性,还进行了实验验证。除了分层之外,还考虑了不同纤维取向的 CFRP 层压的开孔拉伸(OHT)模拟,以验证各向异性裂纹生长预测,并将结果与实验进行了比较。



来源:复合材料力学仿真Composites FEM
ACT断裂复合材料航空航天UGUM裂纹理论材料InVEST
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首次发布时间:2024-11-03
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【新文速递】2023年11月23日复合材料SCI期刊最新文章

今日更新:Composite Structures 2 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 6 篇Composite StructuresFlexural behaviors and failure mechanisms of CFRP sandwich structures with enhanced dual-phase lattice coresWang Yihao, Han Guangchao, Liu Xincheng, Ren Yiru, Jiang Hongyongdoi:10.1016/j.compstruct.2023.117724带有增强型双相晶格芯材的 CFRP 夹层结构的挠曲行为和破坏机制Inspired by bionic/metallurgical microstructures, novel dual-phase lattice/ Carbon Fiber Reinforced Polymer (CFRP) composite sandwich structures are proposed to improve the energy absorption (EA). The composite sandwich structures for different dual-phase strengthening strategies are designed, where the topology optimization is used to yield efficient lattice distribution configurations. The experimental samples are fabricated by 3D-printing and three-point bending tests are conducted. The flexural failure process and failure modes are observed and analyzed to reveal the failure mechanisms. Results show that DPL-1-CFRP and DPL-2-CFRP have higher peak load (+24.8% and 18.0%), post-peak average load (42.6% and 20.8%) and specific energy absorption (+7.8% and +21.1%) compared to SPL-1-CFRP. It is indicated that the interactive failure mechanism of dual-phase lattice is effective in improving the mechanical properties of sandwich structure. It represents the occurrence of synergistic deformation between struts rather than a single brittle fracture. Finally, several potential failure mechanisms for the separation of the core and end faces are revealed. This novel concept and structural design greatly contribute to improve mechanical properties of sandwich structure.受仿生/冶金微结构的启发,提出了新型双相晶格/碳纤维增强聚合物(CFRP)复合材料夹层结构,以改善能量吸收(EA)。设计了不同双相强化策略的复合材料夹层结构,并通过拓扑优化获得了高效的晶格分布配置。通过三维打印技术制作了实验样品,并进行了三点弯曲试验。通过对弯曲破坏过程和破坏模式的观察和分析,揭示了破坏机理。结果表明,与 SPL-1-CFRP 相比,DPL-1-CFRP 和 DPL-2-CFRP 具有更高的峰值载荷(+24.8% 和 18.0%)、峰值后平均载荷(42.6% 和 20.8%)和比能量吸收(+7.8% 和 +21.1%)。这表明双相晶格的交互破坏机制能有效改善夹层结构的机械性能。它代表了支柱之间发生的协同变形,而不是单一的脆性断裂。最后,还揭示了芯材和端面分离的几种潜在失效机制。这种新颖的概念和结构设计大大有助于提高夹层结构的机械性能。High-fidelity computational micromechanics of composite materials using image-based periodic representative volume elementHiguchi R., Yokozeki T., Nishida K., Kawamura C., Sugiyama T., Miyanaga T.doi:10.1016/j.compstruct.2023.117726利用基于图像的周期代表体积元素对复合材料进行高保真微观力学计算This study presents numerical investigations into the progressive damages in unidirectional carbon fiber reinforced plastics (CFRP) using computational micromechanics with an image-based periodic representative volume element (RVE). This RVE modeling approach combines the methodologies of image-based RVE and artificial periodic RVE to reflect the actual fiber packing while retaining geometrical periodicity. For high-fidelity modeling, the RVE model is prepared with more than 200 carbon fibers extracted from X-ray computed tomography images. Both homogenization simulation for elastic properties and unidirectional loading simulations for plastic and fracture properties are carried out. The constitutive model parameters are identified and verified by comparing the experimental and predicted effective (spatially averaged) elastic and plastic properties, and ultimate strength. Then, with the identified parameters, the local damage initiation and propagation mechanism, and their influence on the macroscopic nonlinear stress–strain behaviors are discussed. Finally, the influences of fiber packing on the predicted accuracy of computational micromechanics are discussed by comparing the results between the proposed image-based RVE and simple RVEs with the square and hexagonal arrays.本研究利用基于图像的周期性代表体积元素(RVE)计算微观力学,对单向碳纤维增强塑料(CFRP)的渐进损伤进行了数值研究。这种 RVE 建模方法结合了基于图像的 RVE 和人工周期 RVE 的方法,在保留几何周期性的同时反映了实际的纤维堆积。为了进行高保真建模,RVE 模型是用从 X 射线计算机断层扫描图像中提取的 200 多根碳纤维制作的。对弹性特性进行了均质化模拟,对塑性和断裂特性进行了单向加载模拟。通过比较实验和预测的有效(空间平均)弹性和塑性以及极限强度,确定并验证了构成模型参数。然后,根据确定的参数,讨论了局部损伤的引发和传播机制,以及它们对宏观非线性应力应变行为的影响。最后,通过比较所提出的基于图像的 RVE 与方形和六角形阵列的简单 RVE 的结果,讨论了纤维堆积对计算微观力学预测精度的影响。Composites Part A: Applied Science and ManufacturingNanocomposites of polyethylene with Fe3O4 nanoparticles via surface-initiated ROMP: Thermomechanical, shape memory and photothermal propertiesGao Yuan, Hu Jiawei, Wang Huaming, Liu Liyue, Li Lei, Zheng Sixundoi:10.1016/j.compositesa.2023.107923 聚乙烯与 Fe3O4 纳米粒子通过表面引发的 ROMP 纳米复合材料:热力学、形状记忆和光热特性The nanocomposites of polyethylene with Fe3O4 nanoparticles (NPs) were synthesized via surface-initiated ring-opening metathesis polymerization (SI-ROMP). First, the surfaces of pristine Fe3O4 NPs were functionalized with (5-nicyclo[2.2.1]hept-2-enyl)ethyl]triethoxylsilane. The as-obtained Fe3O4 NPs functionalized with norbornene were used to mediate the ROMP of cyclooctene (COE). By controlling the mass ratios of COE to the surface-functionalized Fe3O4 NPs, the polycyclooctene-grafted Fe3O4 NPs (denoted PCOE-g-Fe3O4 NPs) were obtained with variable contents of Fe3O4 NPs. Finally, these PCOE-g-Fe3O4 NPs were hydrogenated into the corresponding polyethylene-grafted Fe3O4 NPs (PE-g-Fe3O4 NPs). The nanocomposites of PE with Fe3O4 NPs were successfully synthesized as evidenced by the morphologies that the Fe3O4 NPs were well dispersed in PE matrix at the scale of nanometer. The nanocomposites displayed the mechanical properties superior to plain PE. More importantly, the nanocomposites were capable of displaying superparamagnetic, thermally-induced shape memory and photothermal properties. Furthermore, the photothermal behavior can be utilized to trigger the shape memory properties in a non-contact fashion.通过表面引发的开环偏聚聚合(SI-ROMP)合成了聚乙烯与 Fe3O4 纳米粒子(NPs)的纳米复合材料。首先,用(5-二环[2.2.1]庚-2-烯基)乙基]三乙氧基硅烷对原始的 Fe3O4 NPs 表面进行官能化。得到的与降冰片烯官能化的 Fe3O4 NPs 被用于介导环辛烯(COE)的 ROMP。通过控制 COE 与表面功能化 Fe3O4 NPs 的质量比,得到了不同 Fe3O4 NPs 含量的聚环辛烯接枝 Fe3O4 NPs(称为 PCOE-g-Fe3O4 NPs)。最后,这些 PCOE-g-Fe3O4 NPs 被氢化成相应的聚乙烯接枝 Fe3O4 NPs(PE-g-Fe3O4 NPs)。从形态上看,Fe3O4 NPs 在纳米级的聚乙烯基体中分散良好,成功合成了聚乙烯与 Fe3O4 NPs 的纳米复合材料。纳米复合材料的机械性能优于普通聚乙烯。更重要的是,纳米复合材料还具有超顺磁性、热诱导形状记忆和光热特性。此外,光热行为可用于以非接触方式触发形状记忆特性。Mechanical property enhancement of graphene-kenaf-epoxy multiphase composites for automotive applicationsMalik Khurshid, Ahmad Faiz, Shaik Dawood MSI, Islam Mohammad S., Ali Saad, Raza Ali, Ahmed Shahed Chowdhurydoi:10.1016/j.compositesa.2023.107916 提高石墨烯-kenaf-环氧多相复合材料在汽车应用中的机械性能Kenaf composites have a high strength-to-weight ratio, but weak fiber-matrix interface bonding limits their automotive use. To address this, a novel technique was developed to fabricate multiphase composites using graphene nanoplatelets (GNPs), kenaf fibers, and an epoxy matrix. The composites were made using vacuum infusion molding, with the GNPs exfoliated using a bath sonicator for uniform dispersion. The composites modified with 0.2 wt.% GNP showed the most significant improvement in mechanical properties. Specifically, these composites exhibited a 30.5% increase in tensile strength, a 61.5% increase in tensile modulus, a 17.6% increase in flexural strength, a 22.7% increase in flexural modulus, a 35.1% increase in interlaminar shear strength, and a 17.1% increase in fracture toughness. Additionally, the water absorption resistance of the multiphase composites improved by up to 7%. These improvements were attributed to the uniform dispersion of GNPs and improved interlocking with the fiber surface. The developed composite has the potential for interior parts (such as dashboards, interior walls, and luggage compartments) in the automotive vehicle.Kenaf复合材料具有很高的强度重量比,但纤维与基体界面粘合力较弱,限制了其在汽车上的应用。为了解决这个问题,我们开发了一种新技术,使用石墨烯纳米片(GNPs)、Kenaf 纤维和环氧基质制造多相复合材料。复合材料采用真空灌注成型法制造,使用水浴式超声波仪对 GNPs 进行剥离,使其均匀分散。使用 0.2 wt.% GNP 改性的复合材料在机械性能方面的改善最为显著。具体来说,这些复合材料的拉伸强度提高了 30.5%,拉伸模量提高了 61.5%,弯曲强度提高了 17.6%,弯曲模量提高了 22.7%,层间剪切强度提高了 35.1%,断裂韧性提高了 17.1%。此外,多相复合材料的吸水性也提高了 7%。这些改进归功于 GNPs 的均匀分散以及与纤维表面更好的互锁。所开发的复合材料有望用于汽车内饰件(如仪表板、内壁和行李箱)。Composites Part B: EngineeringEffect of fibre concentration on the mechanical properties of welded reinforced polypropyleneMofakhami E., Gervat L., Fayolle B., Miquelard-Garnier G., Ovalle C., Laiarinandrasana L.doi:10.1016/j.compositesb.2023.111111 纤维浓度对焊接增强聚丙烯机械性能的影响The effects of fibre concentration on the mechanical response of welded glass-fibre-reinforced polypropylene (GF-PP) were studied in-depth. The weld ratio is defined as the ratio between the strength of the welded material and that of the bulk material. Experimental observations during tensile tests of unwelded and welded GF-PP have shown a weld ratio reduction as high as 60%. For all conditions studied, no significant change in the polymer matrix was observed. Increasing the fibre content on the welded material was additionally associated with a decrease in the stress at break and the strain at the maximum stress, respectively 68 and 84% for 50 wt% GF-PP. The DIC technique was used to retrieve the local response in the welded zone, showing local strain as high as 19.5 times the macroscopic strain. Using X-ray microtomography, the strain magnification could be explained by the significant increase of the fibre density at the welded zone. It was also shown that at least 2/3 of the fibres were orientated within the weld plane limiting the transverse strain, favouring void nucleation and embrittlement of the material. As a consequence, the rupture can be explained by the amplification of the strain linked with the fibre concentration and orientation of the welded material.深入研究了纤维浓度对焊接玻璃纤维增强聚丙烯(GF-PP)机械响应的影响。焊接率的定义是焊接材料的强度与主体材料的强度之比。在对未焊接和已焊接的 GF-PP 进行拉伸试验时进行的实验观察表明,焊接比的降低幅度高达 60%。在所有研究条件下,都没有观察到聚合物基体发生明显变化。此外,焊接材料纤维含量的增加还与断裂应力和最大应力应变的降低有关,50 wt% GF-PP 的断裂应力和最大应力应变分别降低了 68% 和 84%。DIC 技术用于检索焊接区的局部响应,显示局部应变高达宏观应变的 19.5 倍。利用 X 射线显微层析技术,焊接区纤维密度的显著增加可以解释应变放大的原因。研究还表明,至少有 2/3 的纤维在焊接平面内定向,限制了横向应变,有利于空洞成核和材料脆化。因此,断裂可通过与焊接材料的纤维浓度和取向有关的应变放大来解释。Composites Science and TechnologyComparative study of different bonding interactions on the interfacial adhesion and mechanical properties of MXene-decorated carbon fiber/epoxy resin compositesHu Shaokai, Han Ping, Meng Chao, Yu Ying, Han Shaolong, Wang Haoyu, Wei Gang, Gu Zhengdoi:10.1016/j.compscitech.2023.110352 不同粘合相互作用对 MXene 装饰碳纤维/环氧树脂复合材料界面粘合力和机械性能的比较研究Interfacial adhesion determines the mechanical performance of the carbon fibers-reinforced polymers composites (CFRPs), and different bonding interactions could lead to different degrees of interfacial adhesion and mechanical properties of CFRPs. In order to survey specific influence of different bonding interactions on the interface bonding, further boost the mechanical properties of CFRPs, MXene is decorated onto carbon fiber (CF) surface via Van der Waals force or hydrogen bonds (CF-v-MXene), ionic bonds (CF-i-MXene), and covalent bonds (CF-c-MXene), respectively. Besides, detailed interaction mechanisms of various bonding interactions are also comprehensively investigated. The results indicate that the introduction of MXene is obviously efficient for improving the interface adhesion and mechanical properties of CF/epoxy (CF/EP) composites, and the composites reinforced by CF-c-MXene exhibit the optimal properties. Tremendous improvements of 90.1 % and 110.3 % for the impact strength and interfacial shear strength (IFSS) are achieved compared with the composites reinforced by the unsized CF. The microscopic interfacial structure and fracture failure mode are further observed and analyzed to explore the enhancement mechanisms. This work provides effective guidance and reference for the application of MXene and other similar 2D layered materials, such as Transition Metal Dichalcogenides (TMDCs), to design and manufacture high-quality interface for CFRPs with excellent interfacial and mechanical properties.界面粘附力决定了碳纤维增强聚合物复合材料(CFRP)的力学性能,而不同的键合作用会导致不同程度的界面粘附力和碳纤维增强聚合物复合材料的力学性能。为了研究不同结合相互作用对界面结合的具体影响,进一步提高 CFRP 的力学性能,研究人员分别通过范德华力或氢键(CF-v-MXene)、离子键(CF-i-MXene)和共价键(CF-c-MXene)将 MXene 装饰到碳纤维(CF)表面。此外,还全面研究了各种键的详细相互作用机理。结果表明,引入 MXene 能明显有效地改善 CF/EP 复合材料的界面粘附性和力学性能,而 CF-c-MXene 增强的复合材料则表现出最佳性能。与使用非尺寸 CF 增强的复合材料相比,冲击强度和界面剪切强度(IFSS)分别提高了 90.1% 和 110.3%。此外,还进一步观察和分析了微观界面结构和断裂失效模式,以探索增强机制。这项工作为应用 MXene 和其他类似的二维层状材料(如过渡金属二卤化物)设计和制造具有优异界面和力学性能的 CFRP 的高质量界面提供了有效的指导和参考。Acoustic emission-based failure load prediction for plain woven laminates under quasi-static indentationLiu Yuhang, Huang Kai, Ding Junfeng, Yu Shangyang, Li Zhixing, Zhang Li, Guo Lichengdoi:10.1016/j.compscitech.2023.110355 基于声发射的平纹编织层压板在准静态压痕作用下的破坏载荷预测Composites are widely used in engineering applications, and their penetration resistance is critical for performance and safety. However, testing the failure load of composites directly leads to component failure, making it challenging to evaluate the expected residual capacity. To address this issue, this study proposes an artificial neural network (ANN) method that accurately predicts the penetration failure load of composites using acoustic emission (AE) data. A cyclic loading test schedule is designed to capture the AE data during each cycle, and a relationship between AE data and load ratio (LR) is established. To predict the failure load, an extrapolation method (EM) based on uncertainty is proposed in this paper. This approach enables the prediction of failure load intervals when LR equals 1, with relative errors of less than 7.66 %. In cases where multiple loads are not feasible, the single-point prediction method (SPM) can be used instead of the extrapolation method. However, it is crucial to avoid training AE data during the initial loading stage for accurate predictions. This study recommends a loading ratio of more than 0.1 for optimal results with this approach.复合材料广泛应用于工程领域,其抗穿透性对性能和安全性至关重要。然而,测试复合材料的失效载荷会直接导致部件失效,因此评估预期剩余能力具有挑战性。为了解决这个问题,本研究提出了一种人工神经网络(ANN)方法,利用声发射(AE)数据准确预测复合材料的穿透失效载荷。设计了一个循环加载测试时间表,以捕获每个循环中的声发射数据,并建立了声发射数据与负载率(LR)之间的关系。为了预测失效载荷,本文提出了一种基于不确定性的外推法(EM)。这种方法可以预测 LR 等于 1 时的失效载荷区间,相对误差小于 7.66%。在多负载不可行的情况下,可以使用单点预测法 (SPM) 代替外推法。不过,要想获得准确的预测结果,关键是要避免在初始加载阶段训练 AE 数据。本研究建议加载比应大于 0.1,以获得该方法的最佳结果。Improving delamination resistance of 3D printed continuous fiber-reinforced thermoset composites by multi-scale synergistic toughening of mono-component polyetherketone-cardoWang Feng, Ming Yueke, Yang Fuhong, Xiao Hong, Liu Tianqi, Zhang Chenping, Zhu Yansong, Wang Jie, Duan Yugang, Wang Bendoi:10.1016/j.compscitech.2023.110358 通过单组分聚醚酮-卡多的多尺度协同增韧改善 3D 打印连续纤维增强热固性复合材料的抗分层性能Continuous fiber-reinforced thermoset composites (CFRTCs) 3D printing offers a promising solution to fabricate lightweight, high-strength sophisticated composite structures. However, the delamination resistance of 3D printed CFRTCs is decreased by the weak fiber-matrix and interlayer adhesion caused by the process principle. To increase the interlayer toughness of 3D printed CFRTCs, this study developed a printing matrix toughened by various polyetherketone-cardo (PEK-C) forms by modulating its dissolution state. The results showed that the interlaminar toughening effects of the particle dispersion and dissolved dual form of PEK-C were superior to the insoluble particles or the dissolved PEK-C. As a result, the mode I and mode II interlaminar fracture toughness increased by 112.38 % and 189.01 %, respectively. And the synergistic effect of dual-form PEK-C was determined. Fractographic investigation revealed that the dissolved PEK-C experienced the reaction-induced phase separation initiating a nanoscale thermoplastic phase and developing a multi-scale PEK-C toughening system with the microscale PEK-C particles. Moreover, morphological observation of the particle and PEK-C phases demonstrate multi-scale synergistic toughening mechanisms of mono-component PEK-C. This study presents an innovative technique for interlayer toughening applicable to the CFRTCs 3D printing, illustrates the toughening principle, and shows its promise as a general strategy.连续纤维增强热固性复合材料(CFRTCs)三维打印技术为制造轻质、高强度的精密复合材料结构提供了一种前景广阔的解决方案。然而,由于工艺原理导致纤维基体和层间粘附力较弱,三维打印 CFRTC 的抗分层能力有所下降。为了提高三维打印 CFRTC 的层间韧性,本研究开发了一种通过调节聚醚酮-卡多(PEK-C)的溶解状态来增韧各种聚醚酮-卡多形态的打印基体。结果表明,颗粒分散型和溶解型双形态 PEK-C 的层间增韧效果优于不溶解颗粒或溶解型 PEK-C。因此,模式 I 和模式 II 层间断裂韧性分别提高了 112.38 % 和 189.01 %。并确定了双形态 PEK-C 的协同效应。断裂学研究表明,溶解的 PEK-C 经历了反应诱导的相分离,引发了纳米级热塑性相,并与微尺度 PEK-C 颗粒形成了多尺度 PEK-C 增韧体系。此外,颗粒和 PEK-C 相的形态观察证明了单组分 PEK-C 的多尺度协同增韧机制。本研究提出了一种适用于 CFRTC 三维打印的创新层间增韧技术,说明了增韧原理,并展示了其作为通用策略的前景。Analysis of interfacial characteristics in polymer nanocomposites via visual particle recognition methodology and micromechanical predictive modelsMohsenzadeh R., Soudmand B.H., Najafi A.H., Fattahi M., Uyen D.P.doi:10.1016/j.compscitech.2023.110360 通过视觉颗粒识别方法和微机械预测模型分析聚合物纳米复合材料的界面特性This study examines the morphological features of nano-zeolite nanoparticles incorporated into ultra-high molecular weight polyethylene nanocomposites, known for their excellent biocompatibility and significant potential in structural biomedical applications. The analyses involved qualitative assessments and a statistical approach based on visual particle recognition technique. Scanning electron microscopy was adopted for morphological assessments of impact-fractured surfaces. The scanning electron microscopy observations unveiled the improved dispersion of nanoparticles within the polymer matrix following nano-zeolite incorporation. In the quantitative approach, the nanoparticles size and distribution were systematically determined through tailored histograms, utilizing the customized particle recognition strategy applied to images. This analysis yielded average particle sizes for each composite, further used for calculating the effective elastic moduli of nanocomposites by employing a two-fold micromechanics-based homogenization technique, accounting for interfacial effects. The computation of average particle size based on visual measurements substantially improved the accuracy regarding the quantitative analysis of interphase effects on macroscopic properties, marking a departure from the conventional practice of conducting such calculations by relying on unrealistic particle sizes based on their as-received values before compounding with the polymer.本研究探讨了超高分子量聚乙烯纳米复合材料中纳米沸石纳米颗粒的形态特征,众所周知,超高分子量聚乙烯纳米复合材料具有极佳的生物相容性,在结构性生物医学应用方面潜力巨大。分析包括定性评估和基于视觉颗粒识别技术的统计方法。采用扫描电子显微镜对冲击断裂表面进行形态学评估。扫描电子显微镜观察结果表明,纳米沸石加入后,纳米粒子在聚合物基质中的分散性得到了改善。在定量方法中,利用应用于图像的定制颗粒识别策略,通过定制直方图系统地确定了纳米颗粒的尺寸和分布。这一分析得出了每种复合材料的平均粒度,并通过采用基于微观力学的两重均质化技术,进一步用于计算纳米复合材料的有效弹性模量,同时考虑到界面效应。根据目测结果计算平均粒度大大提高了定量分析相间效应对宏观特性影响的准确性,这标志着该方法已摆脱了传统的计算方法,即根据与聚合物复合前的实际粒度值进行计算。Design and preparation of ternary polymer nanocomposites for high energy density film capacitorsCai Jinxia, Xie Bing, Jiang Yunliang, Lu Jinshan, Li Zeyu, Mao Pu, Marwat Mohsin Ali, Zhang Haibodoi:10.1016/j.compscitech.2023.110361 设计和制备用于高能量密度薄膜电容器的三元聚合物纳米复合材料High discharge energy density (Ue) film capacitors are important for miniaturization and integration in power electronic applications. The Ue of a polymer film is mainly dependent on Weibull's breakdown strength (Eb) and dielectric constant (εr). This work aims to develop ternary nanocomposites composed of polycarbonate (PC), Al2O3 nanoparticles (Al2O3 NPs) and BaTiO3 nanowires (BT NWs) for capacitive energy-storage. Al2O3 NPs have a wide bandgap and are expected to enhance Eb owing to their insulating nature, while BaTiO3 nanowires (BT NWs) are ferroelectric and are expected to provide a high εr. To overcome local electric-field distortion at the interface due to the mismatch in εr, core-shell structured BT@SiO2 NWs are prepared. The Eb of the composite containing 1.0 wt.% Al2O3 NPs and 6.0 wt.% BT@SiO2 NWs can reach 626 MV/m while that of the pure PC is 465 MV/m. As a result, its Ue reaches 12.12 J/cm3, which is improved by 211 % that of the pure PC. Its discharge efficiency is 83.5 %. A finite element analysis corroborates the superiority of the ternary polymer nanocomposites for dielectric energy-storage.高放电能量密度(Ue)薄膜电容器对于电力电子应用的微型化和集成化非常重要。聚合物薄膜的 Ue 主要取决于威布尔击穿强度(Eb)和介电常数(εr)。本研究旨在开发由聚碳酸酯(PC)、Al2O3 纳米粒子(Al2O3 NPs)和 BaTiO3 纳米线(BT NWs)组成的三元纳米复合材料,用于电容储能。Al2O3 NPs 具有宽带隙,由于其绝缘性能,有望提高 Eb 值,而 BaTiO3 纳米线 (BT NWs) 具有铁电性,有望提供较高的εr 值。为了克服εr 不匹配导致的界面局部电场畸变,制备了核壳结构的 BT@SiO2 纳米线。含有 1.0 wt.% Al2O3 NPs 和 6.0 wt.% BT@SiO2 NWs 的复合材料的 Eb 可达到 626 MV/m,而纯 PC 的 Eb 为 465 MV/m。因此,其 Ue 达到 12.12 J/cm3,比纯 PC 提高了 211%。其放电效率为 83.5%。有限元分析证实了三元聚合物纳米复合材料在电介质储能方面的优越性。High-performance carbon fiber reinforced polyether-ether-ketone composite pellets 3D-Printed via screw-extrusion additive manufacturingHu Zhonglue, He Jiawen, Chen Wei, Liu Wei, Ding Jietai, He Chang, Wang Sisi, Ning Fuda, Li Xipingdoi:10.1016/j.compscitech.2023.110362 高性能碳纤维增强聚醚醚酮复合材料颗粒通过螺旋挤出增材制造技术实现 3D 打印The lightweight and high-strength carbon-fiber reinforced polyether-ether-ketone composites (PEEK-CF) are highly favorable for a plethora of strength-demanding and weight-sensitive applications. Yet, the traditional filament-based three-dimensional (3D) printing approaches are limited both in throughput and reinforcement content, leaving a wide gap between the service requirement and attainable strength. In this study, pelletized PEEK-CF composites with high CF content (up to 30 wt%), are successfully printed with a custom-designed screw-extrusion 3D-printer. Microstructural characterization reveals the CFs, averaging around 226 μm long, are generally well aligned along the printing direction. The printed PEEK-CF composites exhibit an outstanding tensile strength, reaching over 190 MPa. Post-print treatment, such as hot compression, can further enhance the strength over 200 MPa. Addtionally, those printed specimens also exhibit superior thermal stability, the tensile strength of which reaches 64 MPa at 250 °C. Overall, the tensile strength of the composites agrees well with the Kelly-Tyson equation. The results of this study may incentivize new strategies for designing and optimizing the performance of 3D-printed PEEK-CF composites.轻质、高强度的碳纤维增强聚醚醚酮复合材料(PEEK-CF)非常适用于大量对强度和重量敏感的应用。然而,传统的基于长丝的三维(3D)打印方法在产量和增强材料含量方面都受到限制,因此在使用要求和可达到的强度之间存在很大差距。在本研究中,使用定制设计的螺旋挤出三维打印机成功打印出了高 CF 含量(高达 30 wt%)的粒状 PEEK-CF 复合材料。微观结构表征显示,平均长度约为 226 μm 的 CF 沿打印方向排列整齐。打印出的 PEEK-CF 复合材料具有出色的拉伸强度,超过 190 兆帕。印刷后处理(如热压)可进一步提高强度,超过 200 兆帕。此外,这些印刷试样还表现出卓越的热稳定性,在 250 °C 时的拉伸强度达到 64 兆帕。总体而言,复合材料的抗拉强度与凯利-泰森方程十分吻合。这项研究的结果可能会促进设计和优化三维打印 PEEK-CF 复合材料性能的新策略。 来源:复合材料力学仿真Composites FEM

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