今日更新：Composite Structures 4 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 8 篇Composite StructuresA quasi-3D hyperbolic formulation for the buckling study of metal foam microplates layered with graphene nanoplatelets-embedded nanocomposite patches with temperature fluctuationsSaeid Zavari, Ali Kaveh, Hossein Babaei, Ehsan Arshid, Rossana Dimitri, Francesco Tornabenedoi:10.1016/j.compstruct.2024.117876用准三维双曲模型研究温度波动下层叠石墨烯纳米片-嵌入式纳米复合材料贴片的金属泡沫微板屈曲问题The work analyzes the buckling behavior of size-dependent microplates with a metal foam core, covered by graphene nanoplatelets (GNPs)-embedded nanocomposite patches. Microplates rest on a bi-parameter elastic substrate, and they are immersed in a thermal environment to observe the effect of temperature fluctuations on their elastic buckling performance. All material properties for each layer of the microstructure are thickness-dependent. A novel quasi-3D shear and normal (Q-3D S-N) hyperbolic theory is here proposed to describe the kinematic relations, accounting for the transverse normal strain. At the same time, a modified couple stress theory (MCST) is employed to account for the size dependence of the mechanical behavior due to the presence of a material length-scale parameter. Using the energy method and virtual work principle, the differential equilibrium equations are derived and solved analytically, where solutions are verified against the existing literature. The study focuses on the impact of different parameters on the normalized critical buckling load (NCBL). Based on the results from the systematic investigation, it is found that the addition of GNPs to the microplate enhances its stiffness, leading to increased values of NCBL, which in turn reduce for an increased imperfection ratio.该研究分析了以金属泡沫为核心、由石墨烯纳米片（GNPs）嵌入式纳米复合材料贴片覆盖的微孔板的屈曲行为。微孔板位于双参数弹性基底上，并浸入热环境中，以观察温度波动对其弹性屈曲性能的影响。微结构各层的所有材料属性都与厚度有关。这里提出了一种新的准三维剪切和法向（Q-3D S-N）双曲理论来描述运动学关系，并考虑了横向法向应变。同时，由于材料长度尺度参数的存在，采用了修正耦合应力理论（MCST）来解释力学行为的尺寸依赖性。利用能量法和虚功原理，推导出微分平衡方程并进行了分析求解，并根据现有文献验证了求解结果。研究重点是不同参数对归一化临界屈曲载荷（NCBL）的影响。根据系统调查的结果发现，在微孔板中添加 GNPs 可增强其刚度，从而提高 NCBL 值，而 NCBL 值又会随着不完善率的增加而降低。Nonlinear combined harmonic resonances of composite cylindrical shells operating in hygro-thermo-electro-magneto-mechanical fieldsBocheng Dong, Rui Zhao, Kaiping Yudoi:10.1016/j.compstruct.2024.117877在湿热-电磁-机械场中工作的复合圆柱壳的非线性组合谐波共振By considering the effects of the hygro-thermo-electro-magnetic environments, von Karman nonlinear terms, and multi-harmonic excitations, a coupled nonlinear vibration modeling of composite cylindrical shells comprising a carbon nanotube-reinforced composite (CNTRC) core and two piezoelectric/magnetic composite (PEMC) skins is developed, and the nonlinear dynamic behaviors of such cylindrical shells under primary, super/sub-harmonic, and combined resonance states are investigated. In the theoretical modeling process, the effective mechanical properties of the CNTRC core are first determined using the mixing and Schapery laws, and the hygro-thermo-electro-magneto-mechanical constitutive relations of the PEMC skins are then formulated. Within the framework of Reissner-Mindlin shell theory, the Lagrangian of the system containing Green-Lagrange and von Karman nonlinear terms is derived, and solution techniques based on the multiscale method are provided to obtain nonlinear frequencies, dynamic responses, and phases of CNTRC-PEMC cylindrical shells under multi-physics fields. Consequently, comparison studies are conducted to validate the correctness of the proposed model from different aspects. Based on this, various resonance and chaos behaviors of such structures subjected to multiple load components are revealed and compared, and the influences of environmental factors and structure composition on the amplitude-frequency curves, time-history responses, and phase planes are explored, with several recommendations and findings being drawn.通过考虑 hygro-thermo-electro-magnetic 环境、von Karman 非线性项和多谐波激励的影响，建立了由碳纳米管增强复合材料 (CNTRC) 内核和两个压电/磁复合材料 (PEMC) 表皮组成的复合圆柱壳的耦合非线性振动模型，并研究了这种圆柱壳在主谐波、超/次谐波和组合共振状态下的非线性动力学行为。在理论建模过程中，首先利用混合定律和沙佩里定律确定了 CNTRC 内核的有效力学性能，然后制定了 PEMC 表皮的湿热-电磁-力学构成关系。在 Reissner-Mindlin 壳体理论框架内，推导出包含 Green-Lagrange 和 von Karman 非线性项的系统拉格朗日，并提供基于多尺度方法的求解技术，以获得 CNTRC-PEMC 圆柱壳体在多物理场下的非线性频率、动态响应和相位。因此，对比研究从不同方面验证了所提模型的正确性。在此基础上，揭示并比较了此类结构在多种载荷成分作用下的各种共振和混沌行为，探讨了环境因素和结构组成对幅频曲线、时程响应和相位平面的影响，并得出了若干建议和结论。Topology optimization of bi-material structures with Iso-XFEMEfstathia Chroni, Serafeim Bakalakos, Gerasimos Sotiropoulos, Vissarion Papadopoulosdoi:10.1016/j.compstruct.2024.117902利用 Iso-XFEM 对双材料结构进行拓扑优化Iso-XFEM is a recently proposed evolutionary topology optimization method, which is based in the extended finite element method (XFEM). Similarly to XFEM, Iso-XFEM utilises the level set approach in order to achieve a high-resolution, smooth, and accurate representation of the design boundary using a fixed finite element mesh. Compared to conventional evolutionary and material density methods for topology optimization, such as SIMP and ESO/BESO, Iso-XFEM exhibits less pronounced mesh dependency, while it completely avoids checkerboard problems and the need for a postprocessing step to produce feasible structural forms. In the present study, Iso-XFEM is extended in order to handle effectively topology optimization problems involving two materials, by introducing enrichment functions in conjunction with a XFEM approximation of the solution. This way, the material interface boundaries and its evolution can be accurately represented during the optimization process. A number of 2D and 3D test cases are presented to confirm the efficiency of the proposed method for the optimum design of bi-material structures.Iso-XFEM 是最近提出的一种基于扩展有限元法 (XFEM) 的进化拓扑优化方法。与 XFEM 类似，Iso-XFEM 利用水平集方法，使用固定的有限元网格实现设计边界的高分辨率、平滑和精确表示。与传统的拓扑优化进化法和材料密度法（如 SIMP 和 ESO/BESO）相比，Iso-XFEM 对网格的依赖性较小，同时完全避免了棋盘问题，也不需要后处理步骤来生成可行的结构形式。在本研究中，为了有效处理涉及两种材料的拓扑优化问题，对 Iso-XFEM 进行了扩展，引入了富集函数和 XFEM 近似解。这样，就能在优化过程中准确地表示材料界面边界及其演变。本文介绍了一些二维和三维测试案例，以证实所提方法在双材料结构优化设计中的效率。Thermal-Mechanical Coupling in Drilling High-Performance CFRP: Scale-span Modeling and Experimental ValidationYong Liu, Zitao Pan, Hao Zhang, Xuwen Jing, Honggen Zhou, Yong Chendoi:10.1016/j.compstruct.2024.117903高性能 CFRP 钻孔中的热机械耦合：尺度跨度建模与实验验证The focus of this study is to explore a scale-span thermal-mechanical coupling method for predicting the dynamic mechanical progressive failure behaviors and predicting thermal damage during the drilling process of Carbon Fiber Reinforced Plastic (CFRP). Initially, a thermal conduction constitutive model of drilling CFRP was developed based on the proposed thermal distribution ratio calculation method. Meanwhile, a dynamic span-scale progressive damage constitutive model for CFRP, incorporating modified micromechanics failure criterion with bilinear damage evolution laws, was proposed, and a bilinear cohesive model, including three damage modes, is employed to simulate interlaminar delamination. Subsequently, a user-defined material subroutine VUMAT was implemented on the ABAQUS/Explicit platform to simulate the thermal-mechanical coupling behaviors of drilling T700S-12K/YPH-23 CFRP using a twist drill bit. Finally, a comprehensive information monitoring platform for CFRP drilling experiments was established to validate the accuracy of the simulation results by considering drilling temperature, thrust force, and hole-wall morphology. The results demonstrate excellent agreement between the established thermal-mechanical coupling span-scale model and the experimental data. Furthermore, the simulation effectively captures the various damage behaviors and thermal conduction phenomenon, that occur during the intact drilling process.本研究的重点是探索一种尺度跨度热机械耦合方法，用于预测碳纤维增强塑料（CFRP）钻孔过程中的动态机械渐进失效行为和预测热损伤。首先，基于所提出的热分布比计算方法，建立了钻孔碳纤维增强塑料的热传导构成模型。同时，还提出了 CFRP 的动态跨度尺度渐进损伤构成模型，该模型结合了改进的微观力学失效准则和双线性损伤演化规律，并采用包含三种损伤模式的双线性内聚模型模拟层间分层。随后，在 ABAQUS/Explicit 平台上实现了用户自定义材料子程序 VUMAT，模拟了使用麻花钻头钻孔 T700S-12K/YPH-23 CFRP 的热机械耦合行为。最后，建立了 CFRP 钻孔实验综合信息监测平台，通过考虑钻孔温度、推力和孔壁形态来验证模拟结果的准确性。结果表明，建立的热-机械耦合跨尺度模型与实验数据非常吻合。此外，模拟还有效地捕捉到了完整钻孔过程中出现的各种损伤行为和热传导现象。Composites Part A: Applied Science and ManufacturingDIC study of strain concentrations and damage within web-flange junctions of pultruded GFRP bridge deckingM. Poulton, W.M. Sebastian, J.T. Mottramdoi:10.1016/j.compositesa.2024.108011拉挤 GFRP 桥面铺板腹板-翼缘连接处应变集中和损坏的 DIC 研究This paper reports an experimental study into damage progression within the web-flange junctions of locally-loaded pultruded glass-fibre reinforced-polymer bridge decking, owing to amplified normal and shear stresses at misaligned fibre-resin interfaces. To that end 3D digital image correlation (DIC) is used in three roles, namely quantifying high strains along misaligned fibre layers, detecting onset of damage and identifying macroscopic damage via patterns in the unfiltered strain fields. Both DIC and strain gauges alongside analytical strain predictions are used to increase confidence in the test data. The DIC data reveal that the strains along the misaligned fibre-resin interfaces were shear dominated, and that a 0.8 mm increase of wrinkle-amplitude led to a 92% increase in peak shear strain. Micro-cracking was detected at approximately 50% of the test load that caused the first delamination. In repeat tests this load dropped by 27% due to random transverse cracks within the roving core.本文报告了对局部加载的拉挤玻璃纤维增强聚合体桥面板腹板-翼缘连接处的损伤进展进行的实验研究，其原因是纤维-树脂界面错位处的法向应力和剪切应力被放大。为此，三维数字图像相关（DIC）被用于三个方面，即量化沿错位纤维层的高应变、检测损伤的开始以及通过未滤波应变场的模式识别宏观损伤。DIC 和应变仪以及分析应变预测都用于提高测试数据的可信度。DIC 数据显示，沿错位纤维-树脂界面的应变以剪切为主，皱褶振幅每增加 0.8 毫米，峰值剪切应变就会增加 92%。在导致首次分层的测试载荷的大约 50%处检测到微裂纹。在重复测试中，由于粗纱芯材内部出现随机横向裂纹，该载荷下降了 27%。Composites Part B: EngineeringGreen strategy based on supercritical-fluid foaming for fabricating rigid microcellular thermoplastic polyimide foams with ultrahigh compressive strengthHaiming Liu, Xiangdong Wang, Chuntai Liu, Hao-Yang Mi, Yaqiao Wang, Shihong Chendoi:10.1016/j.compositesb.2024.111204 基于超临界流体发泡的绿色战略：制造具有超高抗压强度的硬质微孔热塑性聚酰亚胺泡沫塑料Thermosetting polyimide (PI) foams (PIFs) are usually synthesized through chemical foaming; however, this approach is environmentally toxic, and it is difficult to regulate the cell structure, remold the foam, and increase the foam compressive strength. The development of microcellular PIFs with ultrahigh compressive strength and high volume expansion ratio remains a challenge. Herein, thermoplastic PI with a branched structure and flexible ether bonds was synthesized through solution polymerization, and microcellular thermoplastic PIFs (TPIFs) with ultrahigh strength were fabricated via supercritical-carbon-dioxide foaming using 2,4,6-triamino pyrimidine (TAP) as a chain-extender monomer. Subsequently, a lattice model of a closed tetrakaidecahedral cell was used to clarify the relation between the foam compressive strength and polymer cell structure. Experimental results indicate that the optimal thermal imidization temperature is 230 °C and that the resulting branched structure considerably improves viscoelasticity, flame retardancy, and foaming performance. A TAP content of 0.75 g results in branched-structure TPIFs with a mean cell size of 16.8 μm. Notably, at high temperatures and pressures, the compressive strength of TPIFs with 0.75 g TAP is more than nine times of that of TPIFs without TAP. Increasing the TAP content beyond 0.75 g results in a crosslinked structure. Backward differentiation shows that TPIF compression is constant at 0.14–0.18 in the [0,0,1] lattice direction. The proposed physical foaming method is environment-friendly and can sustainably produce TPIFs with a high volume expansion ratio, an adjustable microcellular structure, and outstanding mechanical properties.热固性聚酰亚胺（PI）泡沫（PIF）通常是通过化学发泡合成的，但这种方法对环境有毒，而且难以调节孔结构、重塑泡沫和提高泡沫抗压强度。开发具有超高抗压强度和高体积膨胀比的微孔 PIF 仍是一项挑战。本文通过溶液聚合合成了具有支化结构和柔性醚键的热塑性 PI，并使用 2,4,6 三氨基嘧啶（TAP）作为扩链单体，通过超临界二氧化碳发泡制造了具有超高强度的微孔热塑性 PIF（TPIF）。随后，利用闭合四开十面体晶格模型阐明了泡沫抗压强度与聚合物晶格结构之间的关系。实验结果表明，最佳热亚胺化温度为 230 °C，由此产生的支化结构可显著改善粘弹性、阻燃性和发泡性能。TAP 含量为 0.75 克时，支化结构 TPIF 的平均胞尺寸为 16.8 微米。值得注意的是，在高温高压条件下，含 0.75 克 TAP 的 TPIF 的抗压强度是不含 TAP 的 TPIF 的 9 倍多。将 TAP 含量提高到 0.75 克以上会产生交联结构。反向微分表明，TPIF 在[0,0,1] 晶格方向上的压缩率恒定在 0.14-0.18 之间。所提出的物理发泡方法对环境友好，可持续生产具有高体积膨胀比、可调微孔结构和出色机械性能的 TPIF。Laminated composite fabricated using high-performance polyamine thermoset: Ultra heat resistance and excellent mechanical propertyYilin Shen, Shengtao Wang, Guanben Du, Tao Qin, Shuyang Jiang, Shouqing Liu, Zhigang Duan, Hui Niu, Taohong Lidoi:10.1016/j.compositesb.2024.111209使用高性能聚胺热固性材料制造的层压复合材料：超强耐热性和优异的机械性能Developing polymer composites that can work in harsh environment are important for advancing materials industry. However, the composites generally based-on epoxy or phenolics resins that can endure both extremely high and low temperature are still rather limited. In this work, melamine-hexamethylenediamine (MH) thermoset which is structurally different from conventional matrices was used as matrix resin for woven glass fiber reinforced MH (GFRMH) laminated composite. Owing to the excellent thermostability (Td ≈ 460 °C) and interfacial compatibility of the MH matrix, the fabricated composites exhibited exceptional resistance to extreme temperature and mechanical performances, which are superior to that of the representative commercial epoxy-based composites. Particularly, the heat deflection temperature (HDT) of GFRMH was above 300 °C which is much higher than that of the representative high-performance commercial composites (220–270 °C). Moreover, GFRMH composite exhibited excellent retainability even at 425 °C while severe carbonization and delamination occurred to all the selected commercial products. Further, the GFRMH laminate exhibited flexural strength of 541 MPa at room temperature, higher than that of the commercial products by 80–160 MPa. Remarkably, the flexural strength increased to 852 MPa at 77 K without declining of toughness, suggesting the excellent resistance to cryogenic temperature. In summary, the results of the study disclosed the suitability of MH resin as a new matrix of glass fiber reinforced engineering materials.开发可在恶劣环境中工作的聚合物复合材料对于推动材料行业的发展非常重要。然而，一般来说，基于环氧树脂或酚醛树脂的复合材料能承受极高和极低的温度，但这种复合材料仍然非常有限。在这项研究中，三聚氰胺-六亚甲基二胺（MH）热固性树脂在结构上不同于传统基体，被用作玻璃纤维增强 MH（GFRMH）编织层压复合材料的基体树脂。由于 MH 基体具有优异的热稳定性（Td ≈ 460 °C）和界面相容性，制成的复合材料表现出优异的耐极端温度性能和机械性能，优于具有代表性的商用环氧基复合材料。特别是，GFRMH 的热变形温度（HDT）超过 300 °C，远高于代表性高性能商用复合材料的热变形温度（220-270 °C）。此外，GFRMH 复合材料即使在 425 ℃ 下也表现出优异的保持性，而所有选定的商用产品都出现了严重的碳化和分层现象。此外，GFRMH 复合材料在室温下的抗弯强度为 541 兆帕，比商用产品高出 80-160 兆帕。值得注意的是，在 77 K 时，抗弯强度增加到 852 MPa，而韧性却没有下降，这表明其具有优异的抗低温性能。总之，研究结果表明 MH 树脂适合用作玻璃纤维增强工程材料的新基体。An alternative method to evaluate the micromechanics tensile strength properties of natural fiber strand reinforced polyolefin composites. The case of hemp strand-reinforced polypropyleneF.X. Espinach, F. Vilaseca, Q. Tarrés, M. Delgado-Aguilar, R.J. Aguado, P. Mutjédoi:10.1016/j.compositesb.2024.111211评估天然纤维股增强聚烯烃复合材料微观力学拉伸强度特性的替代方法。麻股增强聚丙烯的案例Micromechanics models allow the prediction of a composite material's properties by adding their phases' contributions to such properties. The models can be used to obtain the intrinsic properties of the reinforcements because are difficult to obtain experimentally. This paper explores a simplified model to obtain the intrinsic strength of natural fibers. This model allows obtaining the value directly from the experimental strength of a composite and the matrix. Other models like the Kelly and Tyson equation have three unknowns, needing the use of mathematical methods to obtain a solution, and the obtained solution sometimes deviates from the expected values for natural fiber-reinforced composites. The proposed equation has been able to evaluate the intrinsic strength of hemp fibers as polypropylene composites at a mean value of 600 MPa. This value agrees with the literature. The proposed method simplifies the obtention of the intrinsic tensile strengths of natural fiber reinforcements and does not need morphologic properties of such reinforcements to obtain a solution, decreasing the costs in time and equipment in comparison to usual models like Kelly and Tyson's. furthermore, the obtained results are like those obtained with other micromechanics approaches and reveal the same information about the intrinsic tensile strength of the reinforcements and the strength of the interface.微观力学模型可以通过添加复合材料各相对复合材料性能的贡献来预测复合材料的性能。这些模型可用于获得难以通过实验获得的增强材料的固有特性。本文探讨了一种简化模型，用于获取天然纤维的固有强度。该模型可直接从复合材料和基体的实验强度中获取数值。其他模型（如凯利和泰森方程）有三个未知数，需要使用数学方法求解，而且求得的解有时会偏离天然纤维增强复合材料的预期值。所提出的方程能够评估麻纤维作为聚丙烯复合材料的内在强度，其平均值为 600 兆帕。该值与文献一致。所提出的方法简化了天然纤维加固材料本征抗拉强度的求解过程，并且不需要这些加固材料的形态特性来求解，与凯利和泰森等常用模型相比，减少了时间和设备成本。此外，所获得的结果与其他微观力学方法获得的结果相同，并揭示了有关加固材料本征抗拉强度和界面强度的相同信息。A coupled ductile damage model for metal matrix composites: Development and applicationQizhen Ren, Zhenming Yue, Celal Soyarslan, Zhanqiu Tan, Fuping Yuan, Zhiqiang Lidoi:10.1016/j.compositesb.2024.111229金属基复合材料韧性损伤耦合模型：开发与应用The prediction of failure behavior in metal matrix composites remains a significant challenge in both composition design and process optimization. An accurate prediction of metal matrix composites damage evolution is a crucial for enhancing the quality of metal matrix composites forming. As the material undergoes plastic deformation, it experiences void initiation and growth, resulting in consequential microstructural transformations, stiffness degradation, and mechanical property shifts. In this work, we employed a model to predict damage progression and stiffness decay in metal matrix composites. Leveraging the Gurson-Tvergaard-Needleman framework, this homogenization model accounts for the impact of the evolution of voids and reinforcing phases, on the composite's mechanical properties. The influences of reinforcing phases on voids nucleation and growth were particularly considered, and also the interaction of voids, matrix, reinforcing phases, and stiffness were integrated to discuss their impacts on damage evolution and mechanical performances of the metal matrix composites. The model was implemented as an Abaqus VUMAT subroutine, with its validity gauged by analyzing the influence of model parameters on failure mechanisms and inherent elastoplastic traits. Utilizing the flanging process of carbon nanotube-reinforced aluminum matrix composites as a case study, a significant agreement was observed between experimental and simulated force-displacement profiles, as well as crack evolution routes.金属基复合材料的失效行为预测仍然是成分设计和工艺优化的重大挑战。准确预测金属基复合材料的损伤演变是提高金属基复合材料成型质量的关键。当材料发生塑性变形时，会出现空洞的产生和增长，从而导致微结构转变、刚度降低和机械性能变化。在这项工作中，我们采用了一个模型来预测金属基复合材料的损伤进展和刚度衰减。利用 Gurson-Tvergaard-Needleman 框架，该均质化模型考虑了空隙和增强相的演变对复合材料机械性能的影响。该模型特别考虑了增强相对空隙成核和生长的影响，还综合考虑了空隙、基体、增强相和刚度之间的相互作用，以讨论它们对金属基复合材料的损伤演变和机械性能的影响。该模型以 Abaqus VUMAT 子程序的形式实现，并通过分析模型参数对破坏机制和固有弹塑性特征的影响来衡量其有效性。以碳纳米管增强铝基复合材料的翻边过程为例，观察到实验和模拟的力-位移曲线以及裂纹演变路线之间存在显著的一致性。Preventing partial discharge in liquid metal polymer composites under steep voltage pulsesOmar Faruqe, Anh Hoang, Pradip Chandra Saha, Amanda Koh, Chanyeop Parkdoi:10.1016/j.compositesb.2024.111206防止液态金属聚合物复合材料在陡电压脉冲下发生局部放电Liquid metal polymer composites (LMPCs) offer viable solutions for deformable electronics, including sensors and actuators. To ensure the longevity of the deformable technologies, partial discharge (PD) must be mitigated as it causes premature material aging and device failure. While studies on the dielectric properties of LMPCs have mainly focused on AC voltage, a large number of deformable applications will inevitably involve power electronics for higher efficiency and power density. Consequently, addressing PD in LMPCs under repetitive steep voltage pulses generated by power electronic switches becomes important. This study employs an electric field cancellation technique using electrets to reduce the PD magnitude and increase the partial discharge inception voltage (PDIV) of LMPCs under steep square voltage waves. We placed either a non-electret or electret thin film on top of LMPC samples and conducted PD experiments in flat and bent test coupon arrangements. The results show that electrets can reduce PD magnitude and increase PDIV in both test arrangements. Furthermore, the study provides deeper insights into the experimental results by conducting the electric field analysis of the LMPC experiments through numerical models.液态金属聚合物复合材料（LMPC）为包括传感器和致动器在内的可变形电子器件提供了可行的解决方案。为确保可变形技术的使用寿命，必须减少局部放电（PD），因为它会导致材料过早老化和器件失效。虽然对 LMPC 介电特性的研究主要集中在交流电压方面，但大量可变形应用将不可避免地涉及电力电子器件，以提高效率和功率密度。因此，解决 LMPC 在电力电子开关产生的重复陡电压脉冲下的 PD 问题变得非常重要。本研究采用了一种使用驻极体的电场消除技术，以降低 LMPC 在陡峭方形电压波下的局部放电幅度并提高局部放电起始电压 (PDIV)。我们在 LMPC 样品的顶部放置了非驻极体或驻极体薄膜，并在平面和弯曲测试券排列中进行了局部放电实验。结果表明，在这两种测试布置中，驻极体都能降低 PD 幅值并提高 PDIV。此外，该研究还通过数值模型对 LMPC 实验进行了电场分析，从而对实验结果有了更深入的了解。Rotating gliding arc plasma: Innovative treatment for adhesion improvement between stainless steel heating elements and thermoplastics in resistance welding of compositesGang Zhao, Mingzhuan Li, Yi Zhao, Xin Zhou, Haitao Yu, Xigao Jian, Shouhai Zhang, Jian Xudoi:10.1016/j.compositesb.2024.111210旋转滑行电弧等离子体：在复合材料电阻焊接中改善不锈钢加热元件与热塑性塑料之间附着力的创新处理方法Rotating gliding arc plasma treatment was conducted on a stainless-steel heating element (HE) for the resistance welding of carbon fiber/polyetheretherketone (CF/PEEK) thermoplastic composites. The lap shear strength of 51.7 MPa, corresponding to an improvement of 14.63 % compared to that of joints welded using untreated HE, was successfully achieved after the plasma treatment. The results of the surface characterization tests revealed that owing to the cleaning and oxidation effects, the hydrophilicity as well as the surface bonding of the HEs were remarkably improved after plasma treatment. Moreover, the reduction of void defects within the welded joints was disclosed via nondestructive inspection of cross-sections, indicating that the enhancement of HE hydrophilicity resulted in the improved resin impregnation and void elimination. Besides, according to the fractographic analysis, the main failure mode changed from the HE/PEEK interfacial damage to a CF/matrix interfacial failure, indicating that the HE/matrix interfacial adhesion was highly strengthened after plasma treatment.对不锈钢加热元件（HE）进行了旋转滑弧等离子处理，用于碳纤维/聚醚醚酮（CF/PEEK）热塑性复合材料的电阻焊接。经等离子处理后，搭接剪切强度达到 51.7 兆帕，与使用未处理 HE 焊接的接头相比提高了 14.63%。表面表征测试结果表明，由于清洁和氧化作用，等离子处理后 HE 的亲水性和表面结合力得到了显著改善。此外，通过对横截面进行无损检测，还发现焊点内的空隙缺陷有所减少，这表明 HE 亲水性的增强改善了树脂浸渍和空隙消除。此外，根据断口分析，主要失效模式从 HE/PEEK 界面破坏转变为 CF/ 基质界面失效，这表明等离子处理后 HE/ 基质界面粘附性得到了高度增强。Channel engineering strategy of precisely modified MOF/nanofiber composite separator for advanced aqueous zinc ion batteriesChun-Yu Liu, Yi-Di Wang, Hongqi Liu, Qi Chen, Xinwei Jiang, Hao Jia, Jian-Ping Langdoi:10.1016/j.compositesb.2024.111227用于先进锌离子水电池的精确改性 MOF/纳米纤维复合隔膜的通道工程策略As the combination of metal-organic framework (MOF) materials with adjustable channels and flexible polymeric matrix, MOF/nanofiber composite separators enable the controllable ion transport behavior, which offers promising candidates for developing novel battery separators. In this study, series MOF functionalized electrospun polyacrylonitrile nanofiber separators were successfully developed via a precisely surface grafting strategy and then served as the separators for highly efficient aqueous zinc (Zn)-ion batteries (ZIBs). Moreover, channel engineering was developed by placing amino (MOF-N) and sulfonic acid groups (MOF-NS) on the channel surface of UIO-66, which then effectively promoted the ion transport progress. In particular, the resultant MOF-NS shows an excellent ionic conductivity (22.81 mS cm−1), improved Zn2+ transference number (0.78), and outstanding cyclic durability. These enhanced properties can be contributed by the effectively promoted dissociation of zinc salts and desolvation processes of hydrated Zn ions through strong ion-dipole interactions, as confirmed by the theoretical simulations. Our work demonstrates the great importance of channel engineering in modifying porous MOFs materials and the strong power of the precisely modified MOF/nanofiber separators in regulating ion transmission behavior and thus offers a promising separator candidate for high performance aqueous ZIBs.作为具有可调通道的金属有机框架（MOF）材料与柔性聚合物基体的结合体，MOF/纳米纤维复合隔膜可实现可控的离子传输行为，为开发新型电池隔膜提供了广阔的前景。在这项研究中，通过精确的表面接枝策略，成功开发出了系列 MOF 功能化电纺聚丙烯腈纳米纤维隔膜，并将其用作高效水性锌（Zn）离子电池（ZIBs）的隔膜。此外，通过在 UIO-66 的通道表面添加氨基（MOF-N）和磺酸基团（MOF-NS），开发了通道工程，从而有效地促进了离子传输过程。特别是，由此产生的 MOF-NS 显示出卓越的离子电导率（22.81 mS cm-1）、更高的 Zn2+ 转移数（0.78）和出色的循环耐久性。理论模拟证实，锌盐的解离和水合锌离子的脱溶过程通过离子-偶极子的强相互作用得到了有效促进，从而增强了这些特性。我们的工作证明了通道工程在改性多孔 MOFs 材料中的重要性，以及精确改性的 MOF/纳米纤维分离器在调节离子传输行为方面的强大功能，从而为高性能水性 ZIB 提供了一种前景广阔的候选分离器。A nacre-inspired thermo conductive and healable nanocomposite captures extremely enhanced stiffness and toughnessHaodong Zhang, Jiaoyang Chen, Shuai Zhou, Jiajie Jing, Jiajun Fudoi:10.1016/j.compositesb.2024.111228 一种由珍珠质启发的导热可愈合纳米复合材料，具有极强的硬度和韧性Polymer-based nanocomposites that exhibit exceptional mechanical properties, rapid self-healing capability, high thermal conductivity, and superior electrical insulation are highly sought after for thermal management applications in modern electrical systems and electronic devices, owing to their versatility, ease of processing, and cost-effectiveness. However, traditional methods for enhancing thermal conductivity often compromise self-healing ability and mechanical and electrical properties. In this study, inspired by nacre, we propose an innovative approach to fabricating nanocomposites with a hierarchical architecture by incorporating boron nitride nanosheets (BNNSs) into a polyurethane matrix through a bottom-up assembly process and lamination technology. Leveraging the nacre-like layered structure and strong interfacial hydrogen bonding interactions, the nanocomposites were successfully transformed from exhibiting brittle fracture to displaying ductile fracture behavior, effectively reconciling the contradiction of high stiffness and toughness. The unique design of the nanocomposite leads to simultaneous enhancement in stiffness (5.3 times), strength (20.1 times), toughness (337.4 times), and fracture toughness (16.4 times) compared to those of the polyurethane matrix. Additionally, the resulting nanocomposites demonstrate excellent self-healing efficiency (∼98 %), high thermal conductivity (8.1 ± 0.3 W m−1 K−1) and superior electrical insulation property (>1012 Ω cm). Overall, our study provides a promising avenue for fabricating polymer-based nanocomposites for thermal management applications, which exhibit multifunctional properties without compromising on mechanical strength, electrical insulation, and self-healing capabilities.聚合物基纳米复合材料具有优异的机械性能、快速自愈能力、高导热性和卓越的电绝缘性，因其用途广泛、易于加工和成本效益高，在现代电气系统和电子设备的热管理应用中备受青睐。然而，提高导热性的传统方法往往会损害自愈能力以及机械和电气性能。在本研究中，我们受珍珠层的启发，提出了一种创新方法，通过自下而上的组装工艺和层压技术，将氮化硼纳米片（BNNSs）融入聚氨酯基体，从而制造出具有分层结构的纳米复合材料。利用纳米层状结构和强大的界面氢键相互作用，纳米复合材料成功地从脆性断裂转变为韧性断裂，有效地调和了高刚度和高韧性之间的矛盾。与聚氨酯基体相比，纳米复合材料的独特设计使其刚度（5.3 倍）、强度（20.1 倍）、韧性（337.4 倍）和断裂韧性（16.4 倍）同时得到增强。此外，纳米复合材料还具有优异的自愈合效率（98%）、高热导率（8.1 ± 0.3 W m-1 K-1）和卓越的电绝缘性能（>1012 Ω cm）。总之，我们的研究为制造热管理应用领域的聚合物基纳米复合材料提供了一种前景广阔的途径，这种复合材料在不影响机械强度、电绝缘和自愈合能力的前提下具有多功能特性。来源：复合材料力学仿真Composites FEM
