【新文速递】2024年3月1日复合材料SCI期刊最新文章_ACT_Mechanical_Optical_System_MAGNET_疲劳_复合材料_化学_电磁兼容_航空_电子_通信_声学_裂纹_材料_太阳能

【新文速递】2024年2月12日复合材料SCI期刊最新文章

今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 1 篇Composite StructuresDamage monitoring of pinned hybrid composite-titanium joints using direct current electrical resistance measurementAndreas Dengg, Christoph Kralovec, Martin Schagerldoi:10.1016/j.compstruct.2024.117972利用直流电阻测量法监测插销式混合材料-钛接头的损坏情况The present research addresses structural health monitoring of pinned, composite-titanium (i.e.: hybrid) joints with the aim of using their lightweight potential and damage tolerance in future aircraft designs. Together with additively manufactured titanium pins, protruding into the carbon-fiber composite, a single-lap shear joint specimen is monitored with direct current electrical resistance measurements (DC ERM) across the overlap, without conductivity-enhancing additives (e.g., carbon nanotubes), but rather with the pins’ complex electrical network that forms with the carbon-fiber composite. For a proof-of-concept demonstration, a structural test with quasi-static, tension-tension loading and unloading is performed. Using digital image correlation, degradation of the joint is monitored. Results are validated by a 2-dimensional finite element model, considering multiple damage states. For DC ERM, a damage indicator is proposed to evaluate the joint’s structural condition. It is shown that typical damage for this joint type reported literature (i.e., cracks occurring at the overlap ends) could be reproduced and detected by the electrical property change across the overlap. Under the given laboratory conditions, the proposed DC ERM damage indicator clearly shows a non-reversible increase in resistance by 3.8% due to damage, starting at first damage initiation and also reflecting further damage growth. Thereby, the method’s capability for damage detection and monitoring is demonstrated.本研究涉及对复合材料-钛（即：混合材料）插销接头的结构健康监测，目的是在未来的飞机设计中利用其轻质潜力和损伤容限。在不使用导电性增强添加剂（如碳纳米管）的情况下，而是利用销钉与碳纤维复合材料形成的复杂电网络，通过跨重叠部分的直流电阻测量（DC ERM）对单圈剪切连接试样进行监测。在概念验证演示中，进行了准静态、拉伸-张力加载和卸载的结构测试。利用数字图像相关性，对接头的退化进行监测。结果通过二维有限元模型进行验证，并考虑了多种损坏状态。针对直流 ERM，提出了一种损伤指标来评估接头的结构状况。结果表明，文献报道的这种接头类型的典型损坏（即发生在重叠端部的裂缝）可以通过整个重叠部分的电特性变化来再现和检测。在给定的实验室条件下，所提出的直流 ERM 损坏指示器清楚地显示出，由于损坏，电阻会出现 3.8% 的不可逆增长，这种增长从最初的损坏开始，同时也反映出损坏的进一步增长。由此可见，该方法具有检测和监测损坏的能力。Composites Part A: Applied Science and ManufacturingOn the surface characteristics and removability of RB-SiC composite processed by nanosecond pulsed laserHong An, Yongfeng Qian, Lin Zhang, Zhiyu Zhang, Hu Huang, Jiwang Yandoi:10.1016/j.compositesa.2024.108082 纳秒脉冲激光加工的 RB-SiC 复合材料的表面特性和可移除性The inherent hard-brittle nature of RB-SiC composite poses significant challenges for efficient machining, hindering its application and promotion. Laser processing is a non-contact treatment technique that can effectively modify the mechanical properties of the material surface, thereby altering its removability. Accordingly, the change in surface characteristics of RB-SiC composite induced by nanosecond laser irradiation was investigated. It was found that laser irradiation could effectively soften the RB-SiC composite (with a maximum reduction in hardness by 40.7%), and the softening degree was strongly dependent on the laser parameters. The chemical composition analysis showed that the SiC content was decreased while the Si content was increased after laser irradiation, which was mainly responsible for the hardness reduction of RB-SiC composite. In addition, compared to the original RB-SiC composite, the laser-irradiated samples exhibited enhanced weight loss during the polishing process. This work gives a feasible route to improve the removability of RB-SiC composite.RB-SiC 复合材料固有的硬脆特性给高效加工带来了巨大挑战，阻碍了其应用和推广。激光加工是一种非接触式处理技术，可有效改变材料表面的机械特性，从而改变其可去除性。因此，我们研究了纳秒激光辐照诱导 RB-SiC 复合材料表面特性的变化。研究发现，激光辐照能有效软化 RB-SiC 复合材料（硬度最大降低 40.7%），且软化程度与激光参数密切相关。化学成分分析表明，激光辐照后 SiC 含量降低，而 Si 含量增加，这是导致 RB-SiC 复合材料硬度降低的主要原因。此外，与原始的 RB-SiC 复合材料相比，激光辐照后的样品在抛光过程中表现出更大的失重。这项工作为改善 RB-SiC 复合材料的可去除性提供了一条可行的途径。Composites Part B: EngineeringOptical wood with switchable solar transmittance for all-round thermal managementHe Gao, Ying Li, Yanjun Xie, Daxin Liang, Jian Li, Yonggui Wang, Zefang Xiao, Haigang Wang, Wentao Gan, Lorenzo Pattelli, Hongbo Xudoi:10.1016/j.compositesb.2024.111287可切换太阳能透过率的光学木，实现全方位热管理Technologies enabling passive daytime radiative cooling and daylight harvesting are highly relevant for energy-efficient buildings. Despite recent progress demonstrated with passively cooling polymer coatings, however, it remains challenging to combine also a passive heat gain mechanism into a single substrate for all-round thermal management. Herein, we developed an optical wood (OW) with switchable transmittance of solar irradiation enabled by the hierarchically porous structure, ultralow absorption in solar spectrum and high infrared absorption of cellulose nanofibers. After delignification, the OW shows a high solar reflectance (94.9%) in the visible and high broadband emissivity (0.93) in the infrared region (2.5–25 μm). Owing to the exceptional mass transport of its aligned cellulose nanofibers, OW can quickly switch to a new highly transparent state following phenylethanol impregnation. The solar transmittance of optical wood (OW-II state) can reach 68.4% from 250 to 2500 nm. The switchable OW exhibits efficient radiative cooling to 4.5 °C below ambient temperature in summer (cooling power 81.4 W m−2), and daylight heating to 5.6 °C above the temperature of natural wood in winter (heating power 229.5 W m−2), suggesting its promising role as a low-cost and sustainable solution to all-season thermal management applications.日间被动辐射冷却和日光采集技术与节能建筑息息相关。尽管最近在被动冷却聚合物涂层方面取得了进展，但要在单一基材中同时结合被动增热机制以实现全方位热管理，仍然具有挑战性。在此，我们开发了一种光学木材（OW），这种木材具有分层多孔结构、超低太阳光谱吸收率和纤维素纳米纤维的高红外吸收率，因此可切换太阳照射的透射率。经脱木质素处理后，OW 在可见光区显示出较高的太阳反射率（94.9%），在红外区（2.5-25 μm）显示出较高的宽带发射率（0.93）。由于其排列整齐的纤维素纳米纤维具有优异的质量传输性能，OW 可以在苯乙醇浸渍后迅速切换到新的高透明状态。从 250 纳米到 2500 纳米，光学木材（OW-II 状态）的太阳透过率可达 68.4%。这种可切换的光学木材在夏季能以低于环境温度 4.5 °C 的温度进行高效辐射制冷（制冷功率为 81.4 W m-2），在冬季能以高于天然木材温度 5.6 °C 的温度进行日光加热（加热功率为 229.5 W m-2）。Composites Science and TechnologyMechanism of gas barrier improvement of graphene/polypropylene nanocomposites for new-generation light-weight hydrogen storageMufeng Liu, Kailing Lin, Mingyu Zhou, Andrew Wallwork, Mark A. Bissett, Robert J. Young, Ian A. Kinlochdoi:10.1016/j.compscitech.2024.110483 用于新一代轻质储氢的石墨烯/聚丙烯纳米复合材料的气体阻隔性改进机理Hydrogen is a promising energy source for the low-carbon economy but light-weight materials with excellent gas barrier properties are needed for its transport and storage. Nanocomposites can deliver such properties, using two-dimensional materials to provide a barrier within the polymer matrix. Herein, we have investigated the optimal characteristics of graphene-based fillers for their use as a hydrogen barrier in a polymer matrix. We employed reduced graphene oxide (rGO) and graphene nanoplatelets (GNPs) that presented distinct filler morphologies and melt-mixed them separately into isotactic polypropylene (PP). A reliable characterisation approach was developed to evaluate the effective aspect ratio of 2D nanomaterials within a polymer matrix by combining BET surface area for the effective thickness and microscopic measurement for lateral size on the microstructure of the nanocomposite samples. The effective aspect ratio values were evaluated to be 153 ± 85 for the rGO and 14 ± 6 the GNPs. Therefore, the rGO outperformed the GNPs in improving both the mechanical and H2 barrier properties of their nanocomposites. The modulus of PP was increased from 1.2 GPa to 2.3 GPa by the addition of 0.9 vol% of the rGO, whereas GNP-filled PP only reached 1.8 GPa by the addition of a higher loading of the GNP (4.6 vol%). The H2 permeability of PP-rGO nanocomposites compared to pure PP was reduced by 40% at 0.9 vol% loading, compared to PP-GNP samples which had a 30% reduction at 4.6 vol% loading. Nielson's model was employed to analyse the results, showing an effective aspect ratio of rGO and GNP to be 165 and 20 respectively, consistent with the characterisation results.氢是低碳经济中一种前景广阔的能源，但其运输和储存需要具有优异气体阻隔性能的轻质材料。纳米复合材料可以利用二维材料在聚合物基体中提供阻隔性，从而实现这种性能。在此，我们研究了石墨烯基填料在聚合物基体中用作氢气屏障的最佳特性。我们采用了还原氧化石墨烯 (rGO) 和石墨烯纳米片 (GNP)，它们呈现出不同的填料形态，并将它们分别熔融混合到异方性聚丙烯 (PP) 中。我们开发了一种可靠的表征方法，通过结合 BET 表面积（有效厚度）和显微镜测量（纳米复合材料样品微观结构的横向尺寸）来评估聚合物基质中二维纳米材料的有效长宽比。经评估，rGO 的有效长宽比值为 153 ± 85，GNPs 为 14 ± 6。因此，在改善纳米复合材料的机械性能和 H2 阻隔性能方面，rGO 优于 GNPs。添加 0.9 Vol% 的 rGO 后，聚丙烯的模量从 1.2 GPa 提高到 2.3 GPa，而添加更多 GNP（4.6 Vol%）后，填充 GNP 的聚丙烯的模量仅达到 1.8 GPa。与纯 PP 相比，PP-rGO 纳米复合材料的 H2 渗透率在 0.9 Vol% 的添加量下降低了 40%，而 PP-GNP 样品在 4.6 Vol% 的添加量下降低了 30%。采用尼尔森模型分析结果显示，rGO 和 GNP 的有效长宽比分别为 165 和 20，与表征结果一致。来源：复合材料力学仿真Composites FEM