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【新文速递】2023年12月19日复合材料SCI期刊最新文章

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今日更新:Composite Structures 2 篇,Composites Part B: Engineering 3 篇

Composite Structures

Characterizing the flexural/damage behavior of Aluminosilicate glass at low/high loading rates: Application of SHPB for mode-1 loading of laminated glass

Muhammad Aamir Raza, Suo Tao, Penghao Pei, Uzair Ahmed Dar, M. Atif, Muhammad Zakir Sheikh, Guozhong Gao, Zhongbin Tang

doi:10.1016/j.compstruct.2023.117816

低/高加载率下铝硅酸盐玻璃的弯曲/损伤行为表征:SHPB在夹层玻璃1型加载中的应用

Understanding the flexural response of monolithic and laminated glass is essential for making informed choices while selecting glass for varying applications. That is because the behavior of monolithic and laminated glass may not necessarily be the same under certain loading conditions and assessing their performance differences helps in determining their suitability for specific applications. The presented work is aimed at quantifying the flexural/damage behavior of monolithic and laminated glass. Quasi-static and dynamic flexural tests were conducted on monolithic and laminated glass in mode-1 loading while maintaining identical loading and support interfaces. In the first phase, quasi-static flexural tests were performed, and results were quantitatively compared by two approaches: Effective Thickness Approximation (ETA) and the theory of Thick Sandwiched Beams (TSB). Experimentally observed deflection corroborated with both the analytical methods; the absolute error remained less than 2.5% and 0.5% for ETA and TSB, respectively. Importantly, failure of the laminate was witnessed at approximately 50% lower force compared to its monolithic counterpart, which was attributed to the span length of the specimen and the interlayer’s shear stiffness. Fractography was performed to elicit Aluminosilicate glass’s mirror constant and fracture surface energy, as 1.86 MN/m3/2 and 3.95 J/m2, respectively. In Phase-2, Dynamic flexural tests were conducted on a novel Electromagnetic Split Hopkinson Pressure Bar (ESHPB), and an experimental-numerical coupled approach was introduced to analyze the results. The results established that the adverse effects of shorter span length on the flexural strength of laminated glass are mitigated, primarily due to the viscoelastic response of the interlayer. The reprographic images attributed the fracture of monolithic and laminated glass specimens solely to the bending-induced stresses.

了解单片和夹层玻璃的弯曲响应对于在选择不同应用的玻璃时做出明智的选择至关重要。这是因为在特定的载荷条件下,单片玻璃和夹层玻璃的性能不一定相同,评估它们的性能差异有助于确定它们在特定应用中的适用性。所提出的工作旨在量化单片和夹层玻璃的弯曲/损伤行为。在保持相同加载界面和支撑界面的情况下,对单片玻璃和夹层玻璃进行了模一加载下的准静态和动态弯曲试验。在第一阶段,进行了准静态弯曲试验,并通过有效厚度近似(ETA)和厚夹层梁理论(TSB)两种方法对结果进行了定量比较。实验观察到的挠度与两种分析方法一致;ETA和TSB的绝对误差分别小于2.5%和0.5%。重要的是,层压板的破坏是在大约50%的低力下发生的,这是由于试件的跨度长度和夹层的剪切刚度。通过断口分析,得出了硅酸铝玻璃的镜面常数和断口表面能分别为1.86 MN/m3/2和3.95 J/m2。在第二阶段,对新型电磁分离式霍普金森压杆(ESHPB)进行了动态弯曲试验,并引入实验-数值耦合方法对试验结果进行了分析。结果表明,较短的跨度长度对夹层玻璃抗弯强度的不利影响得到了缓解,这主要是由于夹层的粘弹性响应。复 制图像将单片和夹层玻璃试样的断裂完全归因于弯曲引起的应力。


NUMERICAL AND EXPERIMENTAL ASSESSMENT OF OPTIMAL MODELING OF LAMINATED GLASS POST-BREAKAGE RESPONSE

Moheldeen Hejazi, Ali Sari

doi:10.1016/j.compstruct.2023.117822

夹层玻璃破碎后响应优化模型的数值与实验评价

Modeling laminated glass response to extreme loading scenarios is a computationally demanding process in designing and analyzing protective structures. Therefore, an optimal modeling scheme requires a delicate trade-off between accuracy and computational demand. This article investigates the failure modeling of laminated glass layups of thin and thick panels (three and 11 layers) under blast loading. This is done by implementing various simulation techniques: the finite element method with element erosion/deletion, the mesh-free method of smoothed particle hydrodynamics, and the hybrid implementation of mesh-based and mesh-free simulation through element conversions into particles. This Article examines the feasibility and limitations of each method, considering both the aspects of accuracy and computational cost in light of experimental testing results obtained from both arena and shock tube scenarios. Mesh sensitivity and the significance of adaptive meshing in capturing the fracture patterns are evaluated. The present paper suggests that using hybrid techniques leads to optimal modeling results. Furthermore, the stability of the modeling results under diverse blast conditions is verified.

在设计和分析防护结构时,模拟夹层玻璃在极端载荷情况下的响应是一个计算要求很高的过程。因此,最优的建模方案需要在精度和计算需求之间进行微妙的权衡。本文研究了爆炸荷载作用下薄板和厚板(3层和11层)夹层玻璃层合结构的破坏模型。这是通过实现各种模拟技术来实现的:具有单元侵蚀/缺失的有限元方法,光滑颗粒流体动力学的无网格方法,以及通过将元素转换为颗粒的基于网格和无网格模拟的混合实现。本文考察了每种方法的可行性和局限性,根据竞技场和激波管场景的实验测试结果,考虑了准确性和计算成本两方面。评估了网格敏感性和自适应网格在捕获断裂模式中的意义。本文认为,采用混合技术可以获得最佳的建模结果。进一步验证了模型在不同爆炸条件下的稳定性。


Composites Part B: Engineering

Mechanical behaviors of three-dimensional chiral mechanical metamaterials

Tiantian Li, Yaning Li

doi:10.1016/j.compositesb.2023.111141

三维手性机械超材料的力学行为

Chiral and achiral mechanical metamaterials are designed via spherical tiling. The 3D chiral designs show an interesting coupled compression-twisting behavior, while the 3D achiral designs show auxetic behavior. Also, besides the cellular-type chiral and achiral designs, composite-type of each design are created by adding soft matrix to the cellular designs. The designs are fabricated via multi-material 3D printing. Mechanical uni-axial compression experiments are performed on the 3D printed specimens and the experimental results are compared with finite element (FE) simulations. By jointly tailoring the chiral geometry and material combination, the effective mechanical properties and the deformation mechanisms can be tuned in a large range. In addition, a continuum-level material model was developed to predict the constitutive relationship. The results show that the material model can well predict the effective mechanical properties of the chiral 3D mechanical metamaterials.

通过球面平铺法设计手性和非手性机械超材料。三维手性设计表现出有趣的压缩-扭转耦合行为,而三维非手性设计则表现出形变行为。此外,除了细胞型手性和非手性设计外,每种设计的复合类型都是通过在细胞设计中添加软矩阵来创建的。这些设计是通过多材料3D打印制造的。对3D打印试件进行了单轴压缩力学实验,并与有限元模拟结果进行了比较。通过手性几何和材料组合的共同裁剪,可以在较大范围内调整有效的力学性能和变形机理。此外,还建立了一个连续级材料模型来预测本构关系。结果表明,该材料模型能较好地预测手性三维机械超材料的有效力学性能。


Highly water-dispersible methylpyridinium salt functionalized reduced graphene oxide and poly(vinyl alcohol) composites

Sangyoon Lee, Jeong-Un Jin, Jae Ryang Hahn, Seongwoo Ryu, Nam-Ho You

doi:10.1016/j.compositesb.2023.111142

高水分散性甲基吡啶盐功能化还原氧化石墨烯和聚乙烯醇复合材料

The main issues with developing graphene as a reinforcement are its mono-dispersive properties and strong interfacial bonding between matrix and graphene. In this study, we synthesized reduced graphene oxide (rGO) that is mono-dispersive in polar solvents, by designing structural isomers (-para and -meta) for poly(vinyl alcohol) (PVA) nanocomposites. The hydrazine-methylpyridine synthesized with different structural isomers was used to reduce and functionalize graphene oxide (GO). The -meta structural isomers showed a higher reduction rate and functional groups on GO than -para due to the difference in electrophilic strain. In particular, the prepared rGO reduced by meta-hydrazine-methylpyridine (m-Py-rGO) exhibited excellent mono dispersive characteristics in water solvents as well as in PVA matrix. As a result, nanocomposites containing 1 wt % m-Py-rGO increased in tensile strength and modulus by 48 % (85.95 MPa) and 82 % (4.27 GPa), respectively, compared to pristine PVA. In this study, a method for manufacturing rGO with excellent dispersibility in water, an inexpensive solvent, and its application method are presented.

开发石墨烯作为增强材料的主要问题是其单分散性和基体与石墨烯之间的强界面键合。在这项研究中,我们通过设计聚乙烯醇(PVA)纳米复合材料的结构异构体(-对异构体和-元异构体),合成了在极性溶剂中单分散的还原性氧化石墨烯(rGO)。用不同结构异构体合成的肼-甲基吡啶对氧化石墨烯进行了还原和功能化。由于亲电应变的差异,-元结构异构体在氧化石墨烯上的还原率和官能团均高于-对结构异构体。其中,间肼-甲基吡啶还原制备的还原氧化石墨烯(m-Py-rGO)在水溶剂和PVA基质中均表现出优异的单分散性。结果表明,与原始PVA相比,含有1 wt % m-Py-rGO的纳米复合材料的抗拉强度和模量分别提高了48 % (85.95 MPa)和82 % (4.27 GPa)。本研究提出了一种制备在水(一种廉价的溶剂)中具有优异分散性的氧化石墨烯的方法及其应用方法。


Use of a commingling process for innovative flax fibre reinforced unidirectional composites

Elouan Guillou, Mahadev Bar, Mario Scheel, Thierry Falher, Timm Weitkamp, Darshil U. Shah, Alexandre Beigbeder, Pierre Ouagne, Alain Bourmaud

doi:10.1016/j.compositesb.2023.111150

使用混合工艺的创新亚麻纤维增强单向复合材料

Optimisation of textile preforms play a crucial role in the development of high-performance biobased composites materials. In this context, the main ambition of this work is to quantify and assess the mechanical properties and behaviour of biocomposite materials made from unidirectional commingled preforms based on flax and poly-(propylene) fibres. To the best of our knowledge, there is no literature examining the effect of the commingling process on the ultrastructure and the mechanical properties of flax fibres. At the scale of the elementary fibre, fibre mechanical properties are observed to be stable after commingling. However, repeated drawing in the commingling process leads to increased cellulose crystallinity and a larger fraction of elementary fibres exhibiting quasi-linear tensile behaviour. The composite materials produced with these commingled flax/poly-(propylene) preforms contain few cortical residues and show a remarkable degree of fibre individualisation. Moreover, they exhibit high Young's modulus and a stress at break of 24 GPa and 194 MPa, respectively, for a fibre volume fraction of 36 %. A substantial drop in properties is however noted at high fibre fractions due increased heterogeneity of the materials. Remarkably, the biocomposites achieved unprecedented transverse modulus and stress at break of 2.3 GPa and 16.5 MPa, respectively. Our results validate the potential and interest in commingling processes for designing a new family of plant fibre composite materials.

纺织预成型的优化在高性能生物基复合材料的发展中起着至关重要的作用。在这种情况下,这项工作的主要目标是量化和评估由基于亚麻和聚丙烯纤维的单向混合预制体制成的生物复合材料的机械性能和行为。据我们所知,目前还没有文献研究混炼过程对亚麻纤维超微结构和力学性能的影响。在初等纤维的尺度上,共混后纤维的力学性能稳定。然而,在混炼过程中反复拉伸会导致纤维素结晶度的增加和更大比例的初等纤维表现出准线性拉伸行为。用这些混合亚麻/聚丙烯预制体生产的复合材料含有很少的皮质残留物,并显示出显著的纤维个性化程度。此外,当纤维体积分数为36% %时,它们具有较高的杨氏模量和断裂应力,分别为24 GPa和194 MPa。然而,由于材料的不均匀性增加,在高纤维馏分时,性能显著下降。值得注意的是,生物复合材料的横向模量和断裂应力分别达到了前所未有的2.3 GPa和16.5 MPa。我们的研究结果验证了设计一种新型植物纤维复合材料的混炼工艺的潜力和兴趣。




来源:复合材料力学仿真Composites FEM
MeshingACTMechanicalMAGNETDeform断裂复合材料理论爆炸材料试验纺织
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首次发布时间:2024-11-05
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【新文速递】2023年12月8日复合材料SCI期刊最新文章

今日更新:Composite Structures 5 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Science and Technology 2 篇Composite StructuresSIMP Phase-field topology optimisation framework to maximise fracture resistance in FGMsPavan Kumar Asur Vijaya Kumar, Pengfei Li, Jose Reinoso, Qi Chang He, Julien Yvonnet, Marco Paggidoi:10.1016/j.compstruct.2023.117750SIMP 相场拓扑优化框架,最大限度提高 FGM 的抗断裂性In this study, we explore the use of SIMP topology optimization and the phase field approach to fracture to maximize fracture resistance in functionally graded materials (FGMs) in the presence of a second phase. We derive a mathematical formulation using a consistent derivation of the second law of thermodynamics to maximize the external work under the constraints of volume fraction. We also demonstrate that, for every distribution of the density function, the topology optimization problem Γ−Converges. We highlight the significant difference between the fracture resistance in FGMs and homogeneous materials. We investigate the crack propagation path along with the optimum topology for the FGM under different grading profiles, elastic mismatch ratio, strength mismatch ratio, and inclusion mismatch ratio. We present several numerical examples to demonstrate the predictive capability of the presented model. A comparison between the initial design guess and the final optimized design is also provided for each example, to further assess the model’s capability.在本研究中,我们探讨了如何利用 SIMP 拓扑优化和相场断裂法,在存在第二相的功能分级材料 (FGM) 中实现断裂阻力最大化。我们利用热力学第二定律的一致推导得出了一个数学公式,即在体积分数的约束下最大化外部功。我们还证明,对于密度函数的每一种分布,拓扑优化问题Γ-收敛。我们强调了 FGM 与均质材料在抗断裂性方面的显著差异。我们研究了不同级配剖面、弹性错配比、强度错配比和包容错配比条件下 FGM 的裂纹传播路径和最佳拓扑结构。我们列举了几个数值示例来证明所提出模型的预测能力。我们还对每个实例的初始设计猜测和最终优化设计进行了比较,以进一步评估模型的能力。Hybrid Deep Convolutional Networks for the Autonomous Damage Diagnosis of Laminated Composite StructuresMuhammad Muzammil Azad, Heung Soo Kimdoi:10.1016/j.compstruct.2023.117792用于层状复合结构自主损伤诊断的混合深度卷积网络This article presents a robust autonomous damage diagnosis method using hybrid deep convolutional networks for the damage diagnosis of laminated composite structures. Inspired by the potential of deep learning models to autonomously extract deep discriminative features and machine learning models that provide better diagnosis on limited data, the current research integrates deep convolutional networks, namely convolutional neural networks (CNN) and convolutional autoencoder (CAE), with support vector machines (SVM) to build hybrid damage detection models. The proposed hybrid models incorporate the advantages of both convolutional operations to extract deep features, and SVM to diagnose using limited feature data. The proposed hybrid models are validated using random vibrational signals for one healthy and two delamination states of laminated composites. The results showed improved damage detection performance compared to the conventional methods, with lower computational costs. Additionally, the hybrid methods autonomously extracted deep discriminative features, eliminating the need for manual damage-sensitive feature extraction.本文针对层状复合材料结构的损伤诊断,提出了一种使用混合深度卷积网络的鲁棒自主损伤诊断方法。受深度学习模型在自主提取深度判别特征和机器学习模型在有限数据上提供更好诊断的潜力的启发,目前的研究将深度卷积网络(即卷积神经网络(CNN)和卷积自动编码器(CAE))与支持向量机(SVM)集成在一起,以建立混合损伤检测模型。所提出的混合模型结合了卷积运算和 SVM 的优点,前者可提取深度特征,后者可利用有限的特征数据进行诊断。针对层状复合材料的一种健康状态和两种分层状态,使用随机振动信号对所提出的混合模型进行了验证。结果表明,与传统方法相比,损伤检测性能提高了,计算成本降低了。此外,混合方法还能自主提取深度判别特征,从而无需手动提取损伤敏感特征。Probabilistic aeroelastic analysis of high-fidelity composite aircraft wing with manufacturing variabilityMichael McGurk, Olivia Stodieck, Jie Yuandoi:10.1016/j.compstruct.2023.117794具有制造变异性的高保真复合材料飞机机翼的概率气动弹性分析Safety margins of aerospace structures can be improved through altering the laminate parameters of composite materials to increase flutter and divergence velocities. Existing work demonstrates the impact of material uncertainties on low-fidelity structural models that are not sufficient to represent realistic aircraft designs. A gap exists in quantifying laminate parameter uncertainties on aeroelasticity for high-fidelity three-dimensional composite structures in realistic tailored designs. This paper puts forward an efficient methodology for uncertainty quantification on the aeroelastic characteristics of three-dimensional composite structures using FE-based parametric composite models and advanced Kriging surrogate models. The methodology is tested on both low and high fidelity case studies to represent the composite wing structure. Similarities between the case studies are observed in the coefficient of variance of all hard flutter modes being within 0.15-1.4% of each other. The difference was found for divergence and soft flutter velocities where the coefficient of variance could be over ten times higher in the high fidelity case. Global sensitivity results revealed similar physical behavior cases can be produced from both studies at early design stages.通过改变复合材料的层压参数来提高扑翼和发散速度,可以改善航空航天结构的安全裕度。现有工作证明了材料不确定性对低保真结构模型的影响,而低保真结构模型不足以代表现实的飞机设计。在量化高保真三维复合材料结构的层状参数不确定性对现实定制设计的气动弹性的影响方面还存在差距。本文利用基于 FE 的参数化复合材料模型和先进的 Kriging 代理模型,提出了一种对三维复合材料结构的气动弹性特性进行不确定性量化的有效方法。该方法在代表复合材料机翼结构的低保真和高保真案例研究中进行了测试。案例研究的相似之处在于所有硬扑翼模式的方差系数都在 0.15-1.4% 之间。不同之处在于发散和软扑翼速度,高保真情况下的方差系数可能高出 10 倍以上。全局灵敏度结果表明,在早期设计阶段,两种研究都能产生类似的物理行为案例。Stability and load carrying capacity of thin-walled composite columns with square cross-section under axial compressionPatryk Rozylo, Hubert Debskidoi:10.1016/j.compstruct.2023.117795方形截面薄壁复合材料柱在轴向压缩下的稳定性和承载能力The study aimed to analyse the stability and load-carrying capacity of compressed thin-walled composite columns subjected to axial compression. The subject of the survey was composite columns with closed square cross-sections made of carbon-epoxy composite. Different lay-ups of the composite material characterised the test specimens - several cases of lay-ups were considered. The application of the subject of the research is closely related to the use of these elements as load-carrying elements of aerospace and building structures. The requirements for such structures are closely related to the provision of a large reserve of load-carrying capacity after buckling. Experimental testing was carried out using a universal testing machine and other testing techniques, where acoustic emission, an optical deformation measurement system, and a digital microscope, among others, were used. Numerical simulations using the finite element method were carried out parallel to the experimental studies. In the case of FEA simulations, original numerical models were developed considering known failure models of the composite material. For both empirical studies and FEM simulations, an in-depth analysis of the buckling and post-buckling states was carried out, considering the failure phase of the composite material. The novelty of the present work was the development of original FEM models, allowing faithful reproduction of experimental studies conducted on physical models, as well as the use of research methods to determine the load-carrying capacity of composite structures.该研究旨在分析受轴向压缩的薄壁复合材料柱的稳定性和承载能力。调查对象是由碳-环氧复合材料制成的具有封闭方形截面的复合材料柱。复合材料的不同铺设方式决定了试样的特性--考虑了多种铺设方式。研究课题的应用与将这些元件用作航空航天和建筑结构的承重元件密切相关。对此类结构的要求与屈曲后提供大量承载能力储备密切相关。实验测试使用了万能试验机和其他测试技术,包括声发射、光学变形测量系统和数码显微镜等。在进行实验研究的同时,还使用有限元法进行了数值模拟。在有限元模拟中,根据已知的复合材料失效模型开发了原始数值模型。在经验研究和有限元模拟中,考虑到复合材料的失效阶段,对屈曲和屈曲后状态进行了深入分析。本研究的新颖之处在于开发了原始有限元模型,从而忠实地再现了在物理模型上进行的实验研究,并利用研究方法确定了复合材料结构的承载能力。On the nonlinear dynamics of a multi-scale flexoelectric cylindrical shellAshgar Faramarzi Babadi, Krzysztof Kamal Żur, Yaghoub Tadi Benidoi:10.1016/j.compstruct.2023.117741论多尺度柔电圆柱壳的非线性动力学The flexoelectric property shows the relationship between the strain gradient and the electric polarization and has a significant effect on static and dynamic responses of structures at small scales such as micro and nano. Nowadays, experimental studies for intelligent/composite ultra-small mechanical systems are complex, challenging, and in most cases still impossible, especially for nonlinear dynamic behavior analysis. For the first time, this study presents an advanced and complex generalized model for the nonlinear vibrations of a piezo-flexoelectric mechanical system based on a cylindrical shell. It should be noted, that the formulated boundary value problem is generalized, well-posed, and can be applied to the system at micro and nano scales. Hamilton's variational principle as well as assumptions of the first-order shear deformation theory (FSDT) and reformulated flexoelectric theory were used to derive equations of motion of the multi-scale intelligent shell system. To introduce nonlinear effects, von-Kármán strains are applied. Appropriate classical and non-classical mechanical/electric boundary conditions as well as higher-order forces and moments are determined to fully close the formulated problem. The Galerkin method combined with the GDQM, supported by the displacement control strategy and the weighted residual method, have been used to discretize and solve the nonlinear governing equations of the shell with different boundary conditions. Good convergence between the current results and the results from previous studies for simpler cases of the shell was proved. Furthermore, the results showed that geometric ratios of the structure, gradation of material properties, thickness of the flexoelectric layers, and the size effect parameter significantly influence the nonlinear frequency of the structure under the direct flexoelectric effect.挠电特性显示了应变梯度与电极化之间的关系,对微米和纳米等小尺度结构的静态和动态响应具有重要影响。目前,智能/复合超小型机械系统的实验研究非常复杂、具有挑战性,在大多数情况下仍无法进行,尤其是非线性动态行为分析。本研究首次针对基于圆柱形壳体的压电柔电机械系统的非线性振动提出了一个先进而复杂的通用模型。值得注意的是,所提出的边界值问题是广义的、求解良好的,可应用于微米和纳米尺度的系统。汉密尔顿变分原理以及一阶剪切变形理论(FSDT)和重构柔电理论的假设被用来推导多尺度智能壳系统的运动方程。为了引入非线性效应,应用了 von-Kármán 应变。确定了适当的经典和非经典机械/电气边界条件以及高阶力和力矩,以完全解决所提出的问题。在位移控制策略和加权残差法的支持下,Galerkin 方法与 GDQM 相结合,用于离散化和求解具有不同边界条件的壳体非线性控制方程。对于较简单的壳体,目前的结果与之前的研究结果具有良好的收敛性。此外,研究结果表明,结构的几何比率、材料特性的等级、挠电层的厚度以及尺寸效应参数对直接挠电效应下结构的非线性频率有显著影响。Composites Part A: Applied Science and ManufacturingUltra-tough architected adhesive joints for integrated composite processing and bondingCharline van Innis, Michal K. Budzik, Thomas Pardoendoi:10.1016/j.compositesa.2023.107949用于集成复合材料加工和粘接的超强结构胶粘剂接头Deployment of advanced polymer-based composites in critical structures requires, among others, breakthroughs in adhesive bonding solutions. Indeed, available methods suffer from limited fracture toughness of adhesives and from time-consuming bonding processes. Here, we demonstrate a novel concept of architected thermoplastic joints with exceptional fracture resistance larger than 5000 J/m2 (4267±846 J/m2), fully integrated with the composite resin transfer molding process, hence simultaneously targeting both limitations. This extreme toughness is activated through controlled 3D printed hollow pattern within a Nylon bondline. A synergetic combination of plastic dissipation, crack deflection, branching and arrest is tuned by changing the pattern characteristics. Three failure regimes are unraveled through fractographic analyses and finite element models. A stress-at-a-distance fracture criterion, identified for each constituent, quantitatively predicts the toughness variations along the crack path. This approach, amenable to dissimilar bonding between metals and composites, paves the road towards novel and higher performance structures and manufacturing approaches.在关键结构中使用先进的聚合物基复合材料需要在粘合剂粘接解决方案方面取得突破。事实上,现有的方法存在粘合剂断裂韧性有限和粘合过程耗时的问题。在这里,我们展示了一种新颖的热塑性塑料接头设计理念,这种接头具有大于 5000 J/m2 (4267±846 J/m2)的超强断裂韧性,并与复合树脂传递成型工艺完全集成,从而同时解决了这两个局限性。这种极强的韧性是通过在尼龙粘合线内控制三维打印中空图案来实现的。通过改变图案特征,可对塑性耗散、裂纹偏转、分支和断裂进行协同组合。通过断裂分析和有限元模型揭示了三种破坏机制。为每种成分确定的距离应力断裂标准可定量预测裂纹路径上的韧性变化。这种方法适用于金属和复合材料之间的异种粘接,为新型高性能结构和制造方法铺平了道路。Composites Science and TechnologyEnhanced design of dual dynamic cross-linked rubber composites: Achieving self-healing and recyclability through imine and metal-ligand bondingLingfeng Cui, Guanyue Zeng, Xin Li, Feng Bian, Yuzhu Xiongdoi:10.1016/j.compscitech.2023.110382 增强双动态交联橡胶复合材料的设计:通过亚胺和金属配体键合实现自愈合和可回收性The quest to confer self-healing and recyclable properties to conventional rubber is a prominent research area in the rubber industry. This study presents the novel construction of a self-healing and recyclable rubber composite by employing imine bond and Cu2+-imine cross-linking the polybutadiene rubber matrix and Cu2+-imidazole groups cross-linking at the silica-rubber interface. The introduction of imine bonded cross-linked imparts high elasticity to the rubber, while the Cu2+-imidazole complex serves as a bridge, enhancing the interfacial interaction between the silica and rubber matrix. The Cu2+-N (Cu2+-imidazole and Cu2+-imine) complexes not only improves silica dispersion but also acts as a sacrificial unit, thereby enhancing the mechanical properties of the rubber composites. The addition of 0.2 mmol anhydrous copper (II) chloride (CuCl2) results in a significant increase in tensile strength and Young's modulus of the samples (1.04 and 3.91 MPa), with improvements of 181 % and 407 %, respectively, compared to the pure samples. Additionally, the highly dynamic nature of the imine bond and the Cu2+-N (Cu2+-imidazole and Cu2+-imine) complexes imparts excellent self-healing and recyclable properties to the material, exhibiting repair efficiency and recycling recovery of up to 90 % (tensile strength). Therefore, this work opens a new avenue for the design and development of self-healing, recyclable rubber composites.赋予传统橡胶自愈合和可回收特性是橡胶行业的一个突出研究领域。本研究通过采用亚胺键和 Cu2+-imine 交联聚丁二烯橡胶基体,以及 Cu2+-imidazole 基团交联白炭黑-橡胶界面,提出了自愈合和可回收橡胶复合材料的新型结构。亚胺键交联的引入为橡胶带来了高弹性,而 Cu2+-imidazole 复合物则起到了桥梁的作用,增强了白炭黑与橡胶基体之间的界面相互作用。Cu2+-N(Cu2+-咪唑和 Cu2+-亚胺)复合物不仅能改善白炭黑的分散性,还能作为牺牲单元,从而提高橡胶复合材料的机械性能。添加 0.2 mmol 的无水氯化铜(II)(CuCl2)后,样品的拉伸强度和杨氏模量显著增加(1.04 和 3.91 兆帕),与纯样品相比,分别提高了 181 % 和 407 %。此外,亚胺键和 Cu2+-N(Cu2+-咪唑和 Cu2+-亚胺)复合物的高动态性质赋予了材料优异的自愈和可回收特性,显示出高达 90% 的修复效率和回收率(拉伸强度)。因此,这项工作为设计和开发自愈合、可回收的橡胶复合材料开辟了一条新途径。UHMWPE fibers reinforced gradient structure to break the thermal-dielectric-mechanical trade-off in high filled polyethyleneLin Pan, Yongliang Wang, Chunfeng Wang, Zhidong Handoi:10.1016/j.compscitech.2023.110375 超高分子量聚乙烯纤维增强梯度结构,打破高填充聚乙烯的热-电-机械平衡In view of the diversified demands for thermal management materials in soaring developments of electrical systems, the high thermally conductive composites often suffer from their poor mechanical properties and electrical insulation. Targeting at enhancing simultaneous thermal conductivity, dielectric and mechanical properties, the fibers reinforced gradient structured polyethylene-based composites consisting of ultrahigh molecular weight polyethylene (UHMWPE) fiber layer and hybrid-filled layer are proposed and successfully prepared by simple overlapping-hot pressing. The fibers collaborated with gradient arrangement of hybrid-filled layer in modulating the temperature, electric and stress field distribution. The resultant as-designed composites exhibit excellent thermal conductivity of 0.91 W/(m·K), ultrahigh tensile strength of 104.7 MPa and superior breakdown strength of 161.5 kV/mm, which are increased by 18%, 1374% and 37% than those of the homogeneous composites, respectively. This work provides a new strategy for manufacturing high-performance polymer-based composites.鉴于电气系统的飞速发展对热管理材料的多样化需求,高导热复合材料往往存在机械性能和电气绝缘性能差的问题。为了同时提高热导率、介电性能和机械性能,我们提出了由超高分子量聚乙烯(UHMWPE)纤维层和混合填充层组成的纤维增强梯度结构聚乙烯基复合材料,并通过简单的重叠热压工艺成功制备了这种复合材料。纤维与混合填充层的梯度排列共同调节了温度、电场和应力场的分布。所制备的复合材料具有 0.91 W/(m-K)的优异热导率、104.7 MPa 的超高拉伸强度和 161.5 kV/mm 的超强击穿强度,分别比均质复合材料提高了 18%、1374% 和 37%。这项工作为制造高性能聚合物基复合材料提供了一种新策略。来源:复合材料力学仿真Composites FEM

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