今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 2 篇，Composites Science and Technology 1 篇Composite StructuresPreparation of microscale multi-layered viscoelastic polymers and analysis of their noise control effects on composite structuresZHANG Jie, YAO Dan, QIN Chao, WANG Ruiqian, LI Jiang, GUO Shaoyundoi:10.1016/j.compstruct.2023.117702制备微尺度多层粘弹性聚合物并分析其对复合结构的噪声控制效果Multi-layered design is an effective method to improve the damping performance of structures. The existing research focuses more on the multi-layered design of the structure from the macro-perspective, but lacks attention to the material itself from the micro-perspective. Thus, whether microscale multi-layered (MML) viscoelastic polymers have advantages in damping performance is not clear. Moreover, damping materials preparation and structural noise control is an interdisciplinary study. The noise and vibration control effect of MML viscoelastic polymers in actual composite structures needs to be further investigated. This paper conducts such a study on these issues. First, two different types of MML viscoelastic polymers, i.e., free damping (FD) and micro-constrained damping (MCD) composites, were prepared, and their material properties were characterized. Second, the frequency-dependent damping loss factors and elastic modulus of the different damping composites were identified. The influences of damping composite types and MML designs on material damping loss factor and elastic modulus were compared. Third, a prediction model of vibroacoustic behaviours of the honeycomb sandwich structure was established and validated to investigate the noise and vibration control effects of the MML damping composites on composite structures. The influences of the types, numbers of layers and application positions of the MML damping composites on the honeycomb sandwich structure were studied. The results indicated that MML design is helpful to improve the damping performance of viscoelastic polymers, but its influence on different damping composites is quite different. For noise control, MML-FD is more suitable for controlling airborne sound propagation, while MML-MCD is more suitable for controlling structural sound propagation.多层设计是提高结构阻尼性能的有效方法。现有研究更多地从宏观角度关注结构的多层设计，而缺乏从微观角度对材料本身的关注。因此，微尺度多层（MML）粘弹性聚合物在阻尼性能方面是否具有优势尚不明确。此外，阻尼材料制备和结构噪声控制是一门交叉学科。MML 粘弹性聚合物在实际复合材料结构中的噪声和振动控制效果有待进一步研究。本文就这些问题进行了研究。首先，制备了两种不同类型的 MML 粘弹性聚合物，即自由阻尼 (FD) 和微约束阻尼 (MCD) 复合材料，并对其材料特性进行了表征。其次，确定了不同阻尼复合材料随频率变化的阻尼损失因子和弹性模量。比较了阻尼复合材料类型和 MML 设计对材料阻尼损失因子和弹性模量的影响。第三，建立并验证了蜂窝夹层结构的振动声学行为预测模型，以研究 MML 阻尼复合材料对复合结构的噪声和振动控制效果。研究了 MML 阻尼复合材料的类型、层数和应用位置对蜂窝夹层结构的影响。结果表明，MML 设计有助于提高粘弹性聚合物的阻尼性能，但其对不同阻尼复合材料的影响却大不相同。在噪声控制方面，MML-FD 更适合控制空气声传播，而 MML-MCD 更适合控制结构声传播。Composites Part A: Applied Science and ManufacturingSynergistic effects of periodic weak spark and spatial electric field for one-step dispersion of carbon-based micro/nanomaterial agglomeratesTian Yu, Li Shuran, Li Mengze, Fu Yihan, Zhu Weidong, Yan Keping, Ke Yinglindoi:10.1016/j.compositesa.2023.107882周期性弱电火花和空间电场对一步法分散碳基微/纳米材料团聚体的协同效应Agglomeration and entanglement pose significant challenges in carbon-based micro/nanomaterials application, hindering the complete expression and fine-tuning of individual properties. A universal spatiotemporal electrified (STE) approach is proposed, which enables the efficient separation of individual constituents from agglomerates, achieving one-step dispersion in the gas phase. This process operates through two features: (1) periodic weak spark loosening and (2) spatial electric field attraction. The periodic weak spark, self-induced and automatically triggered by the material, generates induced electromagnetic fields and shock waves that facilitate repulsion, propulsion, and loosening of the agglomerate structure, endowing the material with capability to overcome the high frictional barriers. Simultaneously, the constructed spatial electric field continuously attracts, selectively separating and outputting individual micro/nanomaterials in real-time. This results in a one-step, concise dispersion process with additional benefits like alignment and blending. Overall, the STE approach has broad applicability and potential to unlock the full capabilities of micro/nanomaterials in various applications.团聚和缠结给碳基微型/纳米材料的应用带来了巨大挑战，阻碍了单个特性的完整表达和微调。本文提出了一种通用的时空电动化（STE）方法，它能有效地将单个成分从团聚体中分离出来，在气相中实现一步分散。该工艺有两个特点：(1) 周期性弱火花松动和 (2) 空间电场吸引。周期性弱火花由材料自发触发，产生感应电磁场和冲击波，促进团聚结构的排斥、推进和松散，赋予材料克服高摩擦障碍的能力。同时，构建的空间电场不断吸引、选择性分离和实时输出单个微/纳米材料。这样，分散过程一步到位，简洁明了，还具有对齐和混合等额外优势。总之，STE 方法具有广泛的适用性和潜力，可在各种应用中释放微/纳米材料的全部能力。Improved Pyroelectric Performances of Functionally Graded Graphene Nanoplatelet Reinforced Polyvinylidene Fluoride Composites: Experiment and ModellingZeng Bowen, Yang Jinlong, Ni Zhi, Fan Yucheng, Hang Ziyan, Feng Chuangdoi:10.1016/j.compositesa.2023.107883功能分级石墨烯纳米板增强聚偏氟乙烯复合材料的热电性能改进：实验与建模Polyvinylidene fluoride (PVDF), as a pyroelectric polymer, has great potential applications in electronic devices and sensors. However, the low pyroelectric properties of pure PVDF limit its application. In this work, functionally graded graphene nanoplatelet (FG-GNP) reinforced PVDF composite films are prepared and test for their pyroelectric performance. Apart from experiments, the pyroelectric properties of the films are modelled and analyzed by finite element analysis (FEA), which is verified by the experiments as conducted. It demonstrates that the pyroelectric properties of FG-GNP/PVDF composite films are significantly improved compared to the homogeneous GNP/PVDF composite counterparts. It is found that for the same thickness and amount of GNP added, the increase in the number of layers leads to enhanced pyroelectric properties of the composite films. When the GNP concentration of the layer closed to the surfaces of the FG-GNP/PVDF composite film is higher, the pyroelectric properties and temperature stability of the film are more favorable.聚偏二氟乙烯（PVDF）作为一种热释电聚合物，在电子设备和传感器领域有着巨大的应用潜力。然而，纯 PVDF 的热释电特性较低，限制了其应用。本研究制备了功能分级石墨烯纳米板（FG-GNP）增强 PVDF 复合薄膜，并对其热释电性能进行了测试。除实验外，还通过有限元分析（FEA）对薄膜的热释电特性进行了建模和分析，并通过实验进行了验证。结果表明，与同质的 GNP/PVDF 复合材料相比，FG-GNP/PVDF 复合薄膜的热电性能得到了显著改善。研究发现，在相同厚度和 GNP 添加量的情况下，层数的增加会增强复合薄膜的热释电特性。当 FG-GNP/PVDF 复合薄膜表面封闭层的 GNP 浓度越高时，薄膜的热释电特性和温度稳定性越好。Composites Science and TechnologySelf-healing and in-situ real-time damage-reporting fiber-reinforced compositeYuan Weihao, Zhang Ziyang, Li Yueshan, Huang Yudong, Zhong Zhengxiang, Hu Zhendoi:10.1016/j.compscitech.2023.110344 自愈合和原位实时损伤报告纤维增强复合材料To increase the service life of composite materials, self-healing, and damage detection are essential. Although a lot of research has been done on self-healing and damage-reporting materials, it is still difficult to combine self-healing with in-situ and real-time damage detection in bulk resin and composites. By integrating extrinsic self-healing based on microcapsules and internal self-healing based on coordination interaction, the simultaneous self-healing of matrix and interface damage of fiber-reinforced composites was achieved in this study. Specifically, two-component microcapsules filled with epoxy/mercaptan repair agent were inserted into the matrix and Ag nanoparticles (AgNPs) were introduced into the surface of carbon fiber by electroless plating. Upon the rupture of microcapsules, matrix self-healing was used to reach a desirable level of synchronous healing efficiency. In the meantime, the excess sulfhydryl reacted with AgNPs on the fibers to establish a coordination bond for interface self-healing. More intriguingly, the high exothermic action of epoxy resin and mercaptan repair agent in the self-healing process was observed when using infrared thermal imaging technology for in-situ and real-time damage detection.为了提高复合材料的使用寿命，自修复和损伤检测是必不可少的。尽管人们对自修复和损伤报告材料进行了大量研究，但仍难以将大块树脂和复合材料的自修复与原位实时损伤检测结合起来。本研究通过整合基于微胶囊的外在自修复和基于配位相互作用的内在自修复，实现了纤维增强复合材料基体和界面损伤的同步自修复。具体来说，将填充有环氧树脂/硫醇修复剂的双组分微胶囊插入基体中，并通过无电解电镀将银纳米粒子（AgNPs）引入碳纤维表面。微胶囊破裂后，基质自愈合可达到理想的同步愈合效率。同时，多余的巯基与纤维上的 AgNPs 发生反应，建立配位键，实现界面自愈合。更有趣的是，利用红外热成像技术进行原位和实时损伤检测时，观察到环氧树脂和硫醇修复剂在自愈合过程中的高放热作用。来源：复合材料力学仿真Composites FEM
