【新文速递】2024年5月31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 Science and Technology 1 篇

Composite Structures

An exponential smoothing multi-head graph attention network (ESMGAT) method for damage zone localization on wind turbine blades

Zhimin Zhao, Nian-Zhong Chen

doi:10.1016/j.compstruct.2024.118224

基于指数平滑多头图关注网络(ESMGAT)的风电叶片损伤区域定位方法

An exponential smoothing multi-head graph attention network (ESMGAT) method is proposed for structural damage zone localization on wind turbine blades. This marks the first time that multi-head graph attention networks are introduced into the AE source zone localization task. This method introduces two key innovations: (1) Damage zone localization for wind turbine blades using only a single sensor. (2) Exceptional localization performance in the presence of noisy AE signals. First, the original AE signals are processed using exponential smoothing to effectively smooth them out and eliminate noise. Next, the smoothed AE signals undergo decomposition through continuous wavelet transform (CWT), and the resulting wavelet coefficients are utilized as node features. Euclidean distances between node features are calculated to assess the connectivity within graphs. Additionally, a new aggregation method is introduced for multi-head graph attention networks to enhance the robustness of the proposed method under noisy conditions. Finally, the effectiveness of the ESMGAT method is validated using the dataset from pencil lead break (PLB) tests conducted on a segment of a wind turbine blade.

提出了一种指数平滑多头图关注网络(ESMGAT)方法，用于风电叶片结构损伤区域定位。这是首次将多头图注意网络引入到声发射源区域定位任务中。该方法引入了两个关键的创新点:(1)仅使用单个传感器进行风力涡轮机叶片损伤区域定位。(2)在有噪声的声发射信号下具有出色的定位性能。首先，对原始声发射信号进行指数平滑处理，有效地消除噪声。然后，对平滑后的声发射信号进行连续小波变换(CWT)分解，得到的小波系数作为节点特征。计算节点特征之间的欧几里得距离来评估图内的连通性。此外，针对多头图注意网络引入了一种新的聚合方法，增强了该方法在噪声条件下的鲁棒性。最后，利用风力涡轮机叶片部分的铅笔芯断头(PLB)测试数据验证了ESMGAT方法的有效性。

Improving defect visibility for composites with long pulse thermography

Yanjie Wei, Yao Xiao

doi:10.1016/j.compstruct.2024.118241

利用长脉冲热成像技术提高复合材料缺陷的可见性

Long pulse thermography (LPT) is widely employed as a non-destructive testing technique owing to its broad detection range, cost-effectiveness and user-friendly nature. This method is suitable for detecting materials with low thermal properties, while the image quality is limited by the blurred edges and low contrast of defects. To address these problems, a method for processing infrared image sequence based on Fourier transform, phase integration, and edge-preserving filters has been proposed. Sequential infrared images undergo phase Fourier analysis (PFA) as a first step, followed by integration of phase difference information across frequencies. Subsequently, the integrated phase image is converted into an 8-bit visual image using a designated enhancement scheme. After this processing, the surface temperature during the cooling period is transformed into latent variables that more accurately reflect the defect information within the sample. These variables eliminate the influence of non-uniform heating and improve the visualization of defects. To evaluate the performance of the proposed method, experiments were conducted on two plant fiber composite planes and compared with alternative infrared signal processing methods. The results demonstrate that the proposed method achieves superior quantitative metrics and effectively extracts defect edge features.

长脉冲热成像技术(LPT)由于其检测范围广、成本效益高、操作方便等优点，被广泛应用于无损检测技术。该方法适用于热性能较低的材料的检测，但缺陷的边缘模糊、对比度低，限制了图像质量。为了解决这些问题，提出了一种基于傅里叶变换、相位积分和边缘保持滤波器的红外图像序列处理方法。序列红外图像首先进行相位傅里叶分析(PFA)，然后对不同频率的相位差信息进行积分。随后，使用指定的增强方案将集成相位图像转换为8位视觉图像。在此处理之后，冷却期间的表面温度被转化为潜在变量，更准确地反映样品内的缺陷信息。这些变量消除了不均匀加热的影响，改善了缺陷的可视化。为了评估该方法的性能，在两个植物纤维复合材料平面上进行了实验，并与其他红外信号处理方法进行了比较。实验结果表明，该方法获得了较好的定量指标，能够有效地提取缺陷边缘特征。

Composites Science and Technology

Integrating high-efficiency thermal channel construction and structural wave absorption design within vertically oriented SiC-coated carbon fibers/silicone resin composites

Nizao Kong, Yuanwei Yan, Min Huang, Kaiwen Hou, Liqin Fu, Kun Jia, Chong Ye, Fei Han

doi:10.1016/j.compscitech.2024.110683

在垂直定向sic涂层碳纤维/硅树脂复合材料中集成高效热通道构建和结构吸波设计

To match the increasing miniaturization and integration of electronic devices, higher requirements are put forward for the electromagnetic wave absorption (EWA) and thermal conductivity (Tc) of heat conduction-microwave absorption integrated materials (HCMWAIMs) to overcome the problems of electromagnetic wave (EMW) pollution and heat accumulation. Herein, a simple and efficient shear force induction technique is used to construct a carbon/magnetic isolation network within the silicone resin matrix, where ferrite particles are well dispersed in vertically oriented SiC-coated carbon fibers array. Benefiting from the orderly interconnection of CFs@SiC in the array, the prepared composites have a high Tc of 7.86 W m−1 K−1. The introduction of magnetic ferrite particles within the CFs@SiC array can induce electrical-magnetic coupling, optimize impedance matching, and enhance EMW attenuation. This synergy of V-CFs@SiC/ferrite isolation network structure gives the composites an excellent effective absorption bandwidth (EAB) of 5.88 GHz and a minimal reflection loss (RLmin) of −47.5 dB at a thickness of 1.5 mm. Moreover, the as-prepared composites exhibit outstanding elastic compressibility of 43.2 % and rebound rate of 45.1 % under a pressure of 35psi. This strategy offers a distinguishing understanding of preparing high-performance HCMWAIMs in modern electronic devices.

随着电子设备的小型化和集成化，人们对热传导-微波吸收集成材料（HCMWAIMs）的电磁波吸收（EWA）和导热（Tc）性能提出了更高的要求，以克服电磁波污染和热量积聚的问题。本文采用简单高效的剪切力感应技术，在硅树脂基体中构建碳/磁隔离网络，其中铁氧体颗粒均匀地分散在垂直取向的碳化硅涂层碳纤维阵列中。得益于阵列中 CFs@SiC 的有序互连，所制备的复合材料具有 7.86 W m-1 K-1 的高 Tc。在 CFs@SiC 阵列中引入磁性铁氧体颗粒可诱导电磁耦合、优化阻抗匹配并增强电磁波衰减。V-CFs@SiC/ 铁氧体隔离网络结构的协同作用使复合材料在厚度为 1.5 毫米时具有 5.88 GHz 的出色有效吸收带宽（EAB）和 -47.5 dB 的最小反射损耗（RLmin）。此外，在 35psi 压力下，制备的复合材料表现出 43.2% 的出色弹性可压缩性和 45.1% 的回弹率。这一策略为制备现代电子设备中的高性能 HCMWAIMs 提供了独特的理解。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年5月15日复合材料SCI期刊最新文章

今日更新：Composite Structures 1 篇，Composites Part B: Engineering 1 篇，Composites Science and Technology 1 篇Composite StructuresAnalysis of lattice deformation originated from residual stress on performance of aluminum nitride-based bulk acoustic wave resonatorsXiyu Gu, Yan Liu, Yuanhang Qu, Min Wei, Xiang Chen, Yaxin Wang, Wenjuan Liu, Bensong Pi, Bo Woon Soon, Yao Cai, Shishang Guo, Chengliang Sundoi:10.1016/j.compstruct.2024.118203残余应力引起的晶格变形对氮化铝体声波谐振器性能的影响分析With the development of MEMS technology to the nanometer scale, the influence of different process conditions on the performance of nano-devices can be calculated through the microscopic changes of materials. During the manufacturing process, the large residual stress from the film stack significantly influences the performance of devices, thereby reducing the wafer yield. Herein, we apply density functional theory to MEMS processes to reveal the intrinsic mechanism of how residual stress affects the performance of aluminum nitride-based bulk acoustic wave (BAW) resonators on an 8-inch high-resistance silicon wafer. The variation rule of physical properties of piezoelectric material aluminum nitride with different residual stresses is calculated via first-principles calculations. Through theory formula derivation, the piezoelectric-coupling constant (Kt2) of the bulk acoustic wave resonator is positively correlated with tensile residual stress, and the resonant frequency (fp, fs) is negatively correlated with tensile residual stress. The measurement results show that the average shifts of Keff2 is 0.12 % within −137 MPa and 183 Mpa residual stress, which is an excellent match with the theory prediction.随着微机电系统技术发展到纳米尺度，可以通过材料的微观变化来计算不同工艺条件对纳米器件性能的影响。在制造过程中，薄膜叠层产生的巨大残余应力会严重影响器件的性能，从而降低晶圆良品率。在此，我们将密度泛函理论应用于 MEMS 工艺，揭示了残余应力如何影响 8 英寸高阻硅晶片上氮化铝基体声波（BAW）谐振器性能的内在机制。通过第一原理计算，得出了压电材料氮化铝的物理性质在不同残余应力下的变化规律。通过理论公式推导，体声波谐振器的压电耦合常数（Kt2）与拉伸残余应力呈正相关，谐振频率（fp、fs）与拉伸残余应力呈负相关。测量结果表明，在-137 兆帕和 183 兆帕残余应力范围内，Keff2 的平均偏移量为 0.12%，与理论预测值非常吻合。Composites Part B: EngineeringAchieving the strength-ductility synergy in ultra-fined grained CNT/2024Al composites via a low-temperature aging strategyZhenyu Liu, Cunsheng Zhang, Jun Yan, Zijie Meng, Liang Chen, Guoqun Zhaodoi:10.1016/j.compositesb.2024.111552 通过低温时效策略实现超细晶CNT/2024Al复合材料的强度-塑性协同效应Synchronous enhancement of strength and ductility is a persistent challenge in the development and application of carbon nanotube (CNT)-reinforced aluminum matrix composites. This study proposed a low-temperature aging strategy to induce the nanoscale precipitates and evade the strength and ductility trade-off dilemma. The composites under various aging conditions were characterized in detail at the macro, micro, and nano scales. The precipitation behavior and strengthening mechanism were investigated systematically. Results indicated that when aged at 100 °C the composite exhibited a better mechanical performance. Compared to as-extruded composites, the yield and ultimate tensile strength of CNT/2024Al composites increased by 82.7% and 64.8%, respectively, whereas the elongation decreased by only 1.1%. The results of microstructure and theoretical estimation suggested the dense nanoscale GP zones were primarily responsible for achieving the strength-ductility synergy. This present study on tailoring precipitate evolution could provide fundamental insights and references to enhance the mechanical properties of aluminum matrix composites.同时提高强度和延展性是碳纳米管增强铝基复合材料发展和应用中一直面临的挑战。本研究提出了一种低温时效策略，以诱导纳米级析出，避免强度和延性的权衡困境。在宏观、微观和纳米尺度上对不同老化条件下的复合材料进行了详细表征。系统地研究了其析出行为和强化机理。结果表明，经100℃时效处理后，复合材料具有较好的力学性能。与挤压态复合材料相比，CNT/2024Al复合材料的屈服强度和极限拉伸强度分别提高了82.7%和64.8%，而伸长率仅下降了1.1%。微观结构和理论计算结果表明，致密的纳米级GP区是实现强度-延性协同的主要原因。本文的研究可为提高铝基复合材料的力学性能提供基础性的见解和参考。Composites Science and TechnologyHigh temperature electrical breakdown and energy storage performance improved by hindering molecular motion in polyetherimide nanocompositesLingyu Yang, Daomin Min, Ziwei Gao, Liuqing Yang, Yuanwei Zhu, Wenfeng Liudoi:10.1016/j.compscitech.2024.110656 通过抑制聚醚酰亚胺纳米复合材料的分子运动，提高了其高温电击穿和储能性能Polyetherimide (PEI) is widely used as a material for high temperature and high power energy storage capacitors in new energy vehicles and other fields. However, as the temperature increases, the electrical conductivity increases and the breakdown strength decreases, which greatly reduces the energy storage density of the capacitor and limits the application range. In order to clarify the influence mechanism of high temperature on the breakdown and energy storage performance of dielectrics, this paper established a charge capture and molecular displacement (CTMD) breakdown model based on the expansion motion of molecular segments to study the charge transport and molecular chain motion process of PEI nanocomposites (PNCs) at high temperature. The results show that at 100°C, compared with pure PEI, the internal maximum molecular displacement of PEI PNCs with appropriate doping content (3wt%) is reduced by 28.79%, and the breakdown strength is increased by 11.20%. Appropriate nano-doping can effectively increase the movement difficulty of molecular chains and reduce the activation volume that provides energy for charge transport. Thus, charge transport is inhibited, current density is reduced, and Joule heat accumulation is avoided. Finally, the high temperature breakdown and energy storage performance are improved.聚醚酰亚胺(PEI)作为高温大功率储能电容器材料广泛应用于新能源汽车等领域。但随着温度的升高，电导率增大，击穿强度降低，大大降低了电容器的储能密度，限制了其应用范围。为了阐明高温对电介质击穿和储能性能的影响机理，本文建立了基于分子段膨胀运动的电荷捕获和分子位移(CTMD)击穿模型，研究PEI纳米复合材料(pnc)在高温下的电荷输运和分子链运动过程。结果表明，在100℃时，与纯PEI相比，适当掺杂量(3wt%)的PEI pnc内部最大分子位移降低了28.79%，击穿强度提高了11.20%。适当的纳米掺杂可以有效地增加分子链的运动难度，减少为电荷输运提供能量的活化体积。因此，电荷输运被抑制，电流密度降低，焦耳热积累被避免。最后，改进了高温击穿和储能性能。来源：复合材料力学仿真Composites FEM