【新文速递】2024年3月15日复合材料SCI期刊最新文章

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今日更新：Composite Structures 3 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Science and Technology 1 篇

Composite Structures

Attention mechanism enhanced spatiotemporal-based deep learning approach for classifying barely visible impact damages in CFRP materials

Kailun Deng, Haochen Liu, Jun Cao, Lichao Yang, Weixiang Du, Yigeng Xu, Yifan Zhao

doi:10.1016/j.compstruct.2024.118030

基于注意力机制的时空深度学习方法，用于对 CFRP 材料中几乎不可见的撞击损伤进行分类

Most existing machine learning approaches for analysing thermograms mainly focus on either thermal images or pixel-wise temporal profiles of specimens. To fully leverage useful information in thermograms, this article presents a novel spatiotemporal-based deep learning model incorporating an attention mechanism. Using captured thermal image sequences, the model aims to better characterise barely visible impact damages (BVID) in composite materials caused by different impact energy levels. This model establishes the relationship between patterns of BVID in thermography and their corresponding impact energy levels by learning from spatial and temporal information simultaneously. Validation of the model using 100 composite specimens subjected to five different low-velocity impact forces demonstrates its superior performance with a classification accuracy of over 95%. The proposed approach can contribute to Structural Health Monitoring (SHM) community by enabling cause analysis of impact incidents based on predicting the potential impact energy levels. This enables more targeted predictive maintenance, which is especially significant in the aviation industry, where any impact incidents can have catastrophic consequences.

现有的大多数热图分析机器学习方法主要集中在热图像或标本的像素时间分布图上。为了充分利用热图中的有用信息，本文提出了一种基于时空的新型深度学习模型，其中包含一种注意力机制。该模型使用捕获的热图像序列，旨在更好地描述不同冲击能量水平对复合材料造成的几乎不可见的冲击损伤（BVID）。该模型通过同时学习空间和时间信息，建立了热成像中的 BVID 模式与相应冲击能量水平之间的关系。使用 100 个受到五种不同低速冲击力作用的复合材料试样对模型进行了验证，结果表明该模型性能优越，分类准确率超过 95%。通过预测潜在的冲击能量水平，对冲击事故进行原因分析，所提出的方法可为结构健康监测（SHM）领域做出贡献。这样就能进行更有针对性的预测性维护，这对航空业尤为重要，因为任何撞击事故都可能造成灾难性后果。

Effects of PVA fibers and multi-walled carbon nanotubes reinforcement on uniaxial compression fatigue properties of Engineered geopolymer composites

Weitao Li, Junpeng An, Yiyan Lu, Shan Li

doi:10.1016/j.compstruct.2024.118028

PVA 纤维和多壁碳纳米管加固对工程土工聚合物复合材料单轴压缩疲劳性能的影响

As a new type of green and environmentally friendly cementing material, engineered geopolymer composites (EGC) have broad application prospects. In this study, uniaxial compression fatigue tests were conducted to investigate the fatigue properties of geopolymer material. A total of 137 samples were tested to investigate the effects of carbon nanotubes content, polyvinyl alcohol (PVA) fibers volume content, and maximum stress level on the fatigue life and deformation of geopolymers. The results showed that the fatigue life of geopolymers obeys Weibull distribution, and PVA fibers and multi-walled carbon nanotubes (MWCNTs) achieved multiscale enhancement of the fatigue life by up to 16.34 times. The total strain accumulation, residual strain, and fatigue stiffness of the geopolymers under fatigue loading exhibited a three-stage evolution rule, with stability within the secondary creep branch. In the process of EGC production, the innovative adoption of optimized MWCNTs surface modification and dispersion strategies improved the uniformity of MWCNTs distribution in the matrix. Scanning electron microscopy (SEM) confirmed the hybridization of MWCNTs and PVA fibers at the microscopic level, which can achieve multi-scale enhancement of geopolymers. This study successfully optimized the content of MWCNTs and PVA fibers, further expanding the application range of composite materials.

工程土工聚合物复合材料（EGC）作为一种新型绿色环保固结材料，具有广阔的应用前景。本研究采用单轴压缩疲劳试验来研究土工聚合物材料的疲劳性能。共测试了 137 个样品，研究碳纳米管含量、聚乙烯醇（PVA）纤维体积含量和最大应力水平对土工聚合物疲劳寿命和变形的影响。结果表明，土工聚合物的疲劳寿命服从威布尔分布，PVA纤维和多壁碳纳米管（MWCNTs）实现了疲劳寿命的多尺度提高，最高提高了16.34倍。土工聚合物在疲劳加载下的总应变累积、残余应变和疲劳刚度呈现出三阶段演化规律，并在二次蠕变分支内保持稳定。在 EGC 生产过程中，创新性地采用了优化的 MWCNTs 表面改性和分散策略，提高了 MWCNTs 在基体中分布的均匀性。扫描电子显微镜（SEM）证实了 MWCNT 与 PVA 纤维在微观层面的杂化，从而实现了土工聚合物的多尺度增强。该研究成功优化了 MWCNTs 和 PVA 纤维的含量，进一步拓展了复合材料的应用范围。

Tool wear in cutting carbon fiber reinforced resin/ceramic matrix composites: A review

Haonan Ma, Zhigang Dong, Zhongwang Wang, Feng Yang, Renke Kang, Yan Bao

doi:10.1016/j.compstruct.2024.118033

切割碳纤维增强树脂/陶瓷基复合材料时的刀具磨损：综述

Carbon fiber reinforced resin/ceramic matrix composites are multiphase materials composed of fiber, interface and matrix. They are increasingly in demand for applications in aerospace, energy, sports, transportation and other fields because of their excellent mechanical properties. However, their non-homogeneous and anisotropic properties cause rapid tool wear during machining, which reduces machining efficiency and aggravates machining damage such as delamination and burr. It seriously restricts the further application of composite materials. A comprehensive understanding of wear mechanism is required to control the tool wear rate in composite machining. However, there is a lack of review of tool wear behavior in composite machining. The present work is focused on the research advances in tool wear issues when machining carbon fiber reinforced resin/ceramic matrix composites. The wear mechanism of carbide, coating and polycrystalline diamond tools under different machining conditions is expounded. Methods for characterizing tool wear are compared. The effect of tool wear on machining quality is summarized. Finally, the development trends and future research content of the tool wear problem are discussed.

碳纤维增强树脂/陶瓷基复合材料是由纤维、界面和基体组成的多相材料。由于其优异的机械性能，在航空航天、能源、体育、交通和其他领域的应用需求日益增长。然而，其非均质和各向异性的特性会导致加工过程中刀具的快速磨损，从而降低加工效率，加剧分层和毛刺等加工损伤。这严重限制了复合材料的进一步应用。要控制复合材料加工中的刀具磨损率，就必须全面了解磨损机理。然而，目前还缺乏对复合材料加工中刀具磨损行为的综述。本研究的重点是加工碳纤维增强树脂/陶瓷基复合材料时刀具磨损问题的研究进展。阐述了硬质合金、涂层和聚晶金刚石刀具在不同加工条件下的磨损机理。比较了表征刀具磨损的方法。总结了刀具磨损对加工质量的影响。最后，讨论了刀具磨损问题的发展趋势和未来研究内容。

Composites Part A: Applied Science and Manufacturing

Mechanism and properties of Super-Toughened ternary blends with unique ‘Tassel-Bundle’ morphology

Jielong Lin, Xueying Wu, Hongyao Xu

doi:10.1016/j.compositesa.2024.108143

具有独特 "流苏-束带 "形态的超增韧三元共混物的机理和性能

Polyamide 6 (PA6) has been widely used in field of automotive, electrical-electronics. However, its intrinsic brittleness and sensitivity to notches necessitates improvements for more desirable overall performance. The super-toughened PA6/maleic anhydride modified styrene-ethylene-butylene-styrene copolymer (mSEBS)/PTFE ternary blends (PA6/mSEBS/PTFE) were designed and carefully investigated. Surprisingly, it is found that the PA6 ternary blends display much better elongation at break by 180 %, which is 6 times higher than normal PA6/mSEBS binary blend. The maximum notched Izod and Charpy impact strength for PA6/mSEBS20/PTFE ternary blend were 98 kJ/m2 and 104 kJ/m2, respectively, while only 35 kJ/m2 for PA6/mSEBS20 binary blends. It is found in mechanism investigation that a novel “tassel-bundle” (TB) network morphology is observed, different from the conventional sea-island morphology observed in PA6/mSEBS binary blends. The forming mechanism of novel “tassel-bundle” structure, and the influence of PTFE on morphology formation and mechanical properties of (PA6/mSEBS/PTFE ternary blends will be investigated respectively

聚酰胺 6（PA6）已广泛应用于汽车和电子电气领域。然而，由于其固有的脆性和对缺口的敏感性，有必要对其进行改进，以获得更理想的整体性能。我们设计并仔细研究了超增韧 PA6/马来酸酐改性苯乙烯-乙烯-丁烯-苯乙烯共聚物（mSEBS）/聚四氟乙烯三元共混物（PA6/mSEBS/PTFE）。结果令人惊讶地发现，PA6 三元共混物的断裂伸长率比普通 PA6/mSEBS 二元共混物高出 6 倍，达到 180%。PA6/mSEBS20/PTFE 三元共混物的最大缺口伊佐德冲击强度和夏比冲击强度分别为 98 kJ/m2 和 104 kJ/m2，而 PA6/mSEBS20 二元共混物只有 35 kJ/m2。机理研究发现，与 PA6/mSEBS 二元共混物中观察到的传统海岛形态不同，在 PA6/mSEBS 二元共混物中观察到了一种新型的 "流苏-束"（TB）网络形态。将分别研究新型 "流苏束 "结构的形成机理以及 PTFE 对 PA6/mSEBS/PTFE 三元共混物形态形成和机械性能的影响。

Composites Science and Technology

Comparison between microstructural analysis of GFRP and CFRP rebars using micro computed tomography (μCT), scanning electron microscope (SEM), and acoustic emission (AE) techniques

Maha Ghaib, Mohammadhadi Shateri, Douglas Thomson, Dagmar Svecova

doi:10.1016/j.compscitech.2024.110545

使用微型计算机断层扫描 (μCT)、扫描电子显微镜 (SEM) 和声发射 (AE) 技术对 GFRP 和 CFRP 螺纹钢的微观结构进行分析比较

The internal micro-structure of glass and carbon fibre-reinforced polymer (FRP) rebars subjected to tensile loading was investigated using micro computed tomography (μCT) and scanning electron microscopy (SEM) images. Three dimensional (3D) and two dimensional (2D) reconstructed μCT images were used to study and quantify the void volume and its distribution along with FRP rebar samples after being subjected to tensile loads. The void volume was observed to increase in all samples as the tensile load on the samples was increased. Acoustic emission (AE) monitoring during the tensile loading was also employed to establish a correlation between the AE parameters and damage evolution in the FRP samples. Cumulative energy of AE signal in frequency domain was used to monitor the progression of the internal damage in the FRP reinforcing rebars. A high correlation was observed between the void volume measured by μCT and SEM and the cumulative energy of the AE signal.

利用微型计算机断层扫描 (μCT)和扫描电子显微镜 (SEM) 图像研究了承受拉伸载荷的玻璃纤维和碳纤维增强聚合物 (FRP) 螺纹钢的内部微观结构。三维（3D）和二维（2D）重建的 μCT 图像用于研究和量化受拉伸载荷后 FRP 螺纹钢样品的空隙体积及其分布。随着样品上拉伸载荷的增加，所有样品的空隙体积都在增加。拉伸加载期间还采用了声发射（AE）监测，以建立 AE 参数与 FRP 样品损坏演变之间的相关性。声发射信号在频域中的累积能量用于监测玻璃纤维增强钢筋内部损伤的进展。通过 μCT 和 SEM 测量的空隙体积与 AE 信号的累积能量之间具有很高的相关性。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年2月28日复合材料SCI期刊最新文章

今日更新：Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 2 篇Composites Part A: Applied Science and ManufacturingPromoting bridging in adhesively bonded composites with polymer inserts: A computational perspectiveDitho Pulungan, Sofyan Andika, Tatacipta Dirgantara, Riza Wirawan, Hermawan Judawisastra, Satrio Wicaksonodoi:10.1016/j.compositesa.2024.108107 用聚合物插入物促进粘合复合材料中的桥接：计算视角Preventing catastrophic failure due to delamination in adhesively bonded carbon fiber reinforced polymer (CFRP) is crucial to enhancing the reliability of structures. Experimental evidence from another study demonstrated that introducing inserts into the adhesive bond line creates bridging, effectively arresting the delamination process. In this paper, a numerical model was proposed to mimic the experiment and then utilized for conducting parametric studies. An embedded cell approach was adopted, representing a double cantilever beam (DCB) with linear-elastic continuum shell elements, beam elements for the bridging bundles, and connector elements for the adhesive. The crack propagation was initiated with adhesive failure and subsequently followed by bridging bundle failure. The numerical simulation results closely replicated the experiment’s global response in the force–displacement curve, thereby effectively validating the existence of the bridging effect. Furthermore, our study revealed that enhancing the adhesive strength and insert ductility can further improve crack resistance.防止因粘合碳纤维增强聚合物（CFRP）分层而导致的灾难性失效对于提高结构的可靠性至关重要。另一项研究的实验证据表明，在粘合剂粘合线中引入插入物可产生桥接，有效阻止分层过程。本文提出了一个数值模型来模拟实验，然后利用该模型进行参数研究。该模型采用嵌入式单元方法，用线性弹性连续壳元素表示双悬臂梁 (DCB)，用梁元素表示桥接束，用连接器元素表示粘合剂。裂纹扩展始于粘合剂失效，随后桥接束失效。数值模拟结果与实验中力-位移曲线的全局响应密切相关，从而有效验证了桥接效应的存在。此外，我们的研究还发现，提高粘合强度和插入延展性可进一步改善抗裂性。Composites Part B: Engineering4D printed multifunctional wearable strain sensors with programmable sensing characteristicsJifeng Zhang, Xue Yang, Wangxuan Li, Hongpei Liu, Zhifu Yin, Yangbo Chen, Xueli Zhoudoi:10.1016/j.compositesb.2024.111346具有可编程传感特性的 4D 印刷多功能可穿戴应变传感器Combining 4D-printed bilayer actuators with the slit structure and sensing capabilities unique to the process further promotes the use of 4D printing in biomedical devices, human-computer interaction, intelligent self-protection devices, and humanoid robots. In this study, we propose an adaptive multifunctional strain sensor (AMSS) 4D printing strategy based on the shape memory properties of polylactic acid (PLA), a bioslit structural sensing unit, and a bi-directional deformation design of a bilayer structure. The obtained AMSS was shown to have excellence sensitivity to strain, mechanical, and temperature stimuli. In particular, thanks to the 3D printed slit structure and phase transition properties of the PLA printing layer, the AMSS macro-microstructure can be precisely tuned, and its sensing performance is shown to be intelligently programmable. The built-in structural design-induced macro-deformation enables AMSS to adaptively fit human joint surfaces for full-range human motion recognition. In addition, the close correlation of strain-sensing during AMSS shape transformation enables position self-sensing and strain self-sensing of AMSS. Further, through the integration and separation of resistive signals, we are able to recognize temperature and mechanical stimuli. Finally, we integrate the wireless sensing module into the AMSS to improve the portability and wearability of the sensor.将 4D 印刷双层致动器与该工艺特有的缝隙结构和传感功能相结合，可进一步促进 4D 印刷在生物医学设备、人机交互、智能自我保护设备和仿人机器人中的应用。在这项研究中，我们基于聚乳酸（PLA）的形状记忆特性、生物光结构传感单元和双层结构的双向变形设计，提出了一种自适应多功能应变传感器（AMSS）4D 打印策略。结果表明，获得的 AMSS 对应变、机械和温度刺激具有卓越的灵敏度。特别是，得益于三维打印狭缝结构和聚乳酸打印层的相变特性，AMSS 的宏观微观结构可以被精确调整，其传感性能被证明是智能可编程的。内置结构设计引起的宏观变形使 AMSS 能够自适应地贴合人体关节表面，从而实现全方位的人体运动识别。此外，AMSS 形状变换过程中的应变感应密切相关，实现了 AMSS 的位置自感应和应变自感应。此外，通过整合和分离电阻信号，我们还能识别温度和机械刺激。最后，我们将无线传感模块集成到 AMSS 中，以提高传感器的便携性和可穿戴性。A continuum damage model for Mg/Al composite sheets rolling: Theoretical development and applicationTao Wang, Chenchen Zhao, Gang Zhang, Wenqiang Zhao, Qingxue Huangdoi:10.1016/j.compositesb.2024.111347镁铝复合材料板材轧制连续损伤模型：理论发展与应用Edge cracks, which are typical formability defects, severely limit the widespread application of Mg/Al composite sheets. Accurate prediction of damage is crucial for understanding the underlying mechanisms behind crack formation. In this study, a continuum damage model that incorporates the stress-state function and effective equivalent plastic strain into the standard Lemaitre model is proposed. This enhanced model effectively addresses the issues of damage-evolution linearization and tension–compression asymmetry in the standard Lemaitre model. Thus, it can be successfully applied to predict the fracture response of ductile composite materials under pressure-forming conditions. Considering AZ31B Mg alloy and 5052 Al alloy as experimental materials, physical experiments and numerical validation are performed under a 50% reduction and 350 °C. The findings show that the proposed model effectively captures crack initiation and propagation during the rolling process, with errors of only 23.1% and 19.9% for average crack quantity and length, respectively. Results of numerical analysis reveals that the high-stress triaxiality at the edge of the sheet contributes significantly to crack formation. Additionally, the strain along the normal direction in the Al alloy significantly affects crack propagation and the formation of serrated cracks on the side of Mg alloy. This study provides important theoretical foundations for the development of Mg-based composite sheets.边缘裂纹是典型的成型缺陷，严重限制了镁/铝复合材料板材的广泛应用。准确预测损伤对于理解裂纹形成背后的基本机制至关重要。本研究提出了一种将应力状态函数和有效等效塑性应变纳入标准勒梅特模型的连续损伤模型。这种增强型模型有效地解决了标准 Lemaitre 模型中损伤演变线性化和拉伸-压缩不对称的问题。因此，该模型可成功用于预测压力成型条件下韧性复合材料的断裂响应。以 AZ31B Mg 合金和 5052 Al 合金为实验材料，在减薄 50%、温度为 350 ℃ 的条件下进行了物理实验和数值验证。结果表明，所提出的模型能有效捕捉轧制过程中裂纹的产生和扩展，平均裂纹数量和长度的误差分别仅为 23.1% 和 19.9%。数值分析结果表明，板材边缘的高应力三轴性在很大程度上导致了裂纹的形成。此外，铝合金沿法线方向的应变也对裂纹扩展和镁合金侧面锯齿状裂纹的形成产生了重要影响。这项研究为镁基复合材料板材的开发提供了重要的理论基础。来源：复合材料力学仿真Composites FEM