【新文速递】2024年1月7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 2 篇，Composites Part B: Engineering 5 篇，Composites Science and Technology 2 篇Composite StructuresA NOVEL DESIGN MODEL FOR PREDICTING THE SHEAR RESISTANCE OF REINFORCED CONCRETE BEAMS STRENGTHENED WITH EBR-CFRP SYSTEMSAmirhossein Mohammadi, Joaquim A.O. Barros, Jose Sena-Cruzdoi:10.1016/j.compstruct.2024.117901预测采用 EBR-CFRP 系统加固的钢筋混凝土梁抗剪性能的新型设计模型Shear resistance prediction of reinforced concrete (RC) beams strengthened with externally bonded reinforcements (EBR) is a challenging task due to the complex nature of shear resisting mechanisms and their intricate interaction. Existing design models often overlook these dependencies, leading to significant variations in prediction accuracy. In this paper, a design model is proposed by integrating the most relevant shear resisting mechanisms based on the evidence demonstrated by a large database of experimental results from RC beams shear strengthened with wet layup carbon fibre reinforced (CFRP) sheets applied according to the EBR technique. The developed approach integrates the simplified modified compression field theory (SMCFT) with a regression-based model. A global sensitivity analysis was conducted according to which closed form equations were derived to obtain the tensile stress factor in cracked concrete and the inclination angle of the critical diagonal crack. A reliability analysis is carried out, and resistance reduction factors are achieved for different levels of reliability index. The database, composed of 284 RC beams shear strengthened with EBR-CFRP technique, is utilized to validate the proposed model, and compare its performance against some well-established existing design models. The results show that the proposed model, with an adequate framework for its use on design practice, outperforms the other considered models.由于抗剪机理的复杂性及其错综复杂的相互作用，对外部粘结钢筋（EBR）加固的钢筋混凝土（RC）梁进行抗剪预测是一项具有挑战性的任务。现有的设计模型通常会忽略这些依赖关系，从而导致预测精度的显著差异。本文提出了一种设计模型，该模型以大型数据库中根据 EBR 技术应用湿铺碳纤维增强（CFRP）板材对 RC 梁进行剪切加固的实验结果为依据，整合了最相关的抗剪机理。所开发的方法将简化修正压缩场理论（SMCFT）与基于回归的模型相结合。进行了全局敏感性分析，并据此推导出封闭式方程，以获得开裂混凝土中的拉应力系数和临界对角线裂缝的倾角。此外，还进行了可靠性分析，并得出了不同可靠性指数水平下的阻力降低系数。利用由 284 根采用 EBR-CFRP 技术剪切加固的 RC 梁组成的数据库来验证所提出的模型，并将其性能与一些成熟的现有设计模型进行比较。结果表明，所提出的模型在设计实践中具有适当的使用框架，其性能优于其他考虑过的模型。Composites Part A: Applied Science and ManufacturingModified Fourier Transform Misalignment Analysis multi-rotate method for measuring fibre alignment in stitched glass fabricsN. Shepherd, T. Allen, M. Battleydoi:10.1016/j.compositesa.2024.108013用于测量缝合玻璃纤维织物纤维排列的修正傅立叶变换错位分析多旋转法Measurements of fibre alignment are important for assessing the quality of fibre reinforced composite materials. The Fourier-Transform Misalignment Analysis (FTMA) algorithm is able to measure the average alignment of features over an area, and is therefore well-suited to measuring fibre alignment in low-magnification images. In images with few pixels, the precision of the FTMA algorithm depends on the alignment of the image features. Features at 45° can be measured with greater precision than those near 0 or ±90°. To combat this, a new FTMA-MultiRotate method is proposed. This modified algorithm has been assessed against computer-generated images, where it is able to achieve an average accuracy within ±0.5°. It has then further been applied to measure fibre alignment in low-magnification photographs of glass fabrics, and these measurements have been verified against measurements taken manually. In 93% of cases, agreement between the modified FTMA-MultiRotate algorithm and manual measurements is within ±1.5°.纤维排列测量对于评估纤维增强复合材料的质量非常重要。傅立叶变换错位分析（FTMA）算法能够测量一个区域内特征的平均对齐情况，因此非常适合测量低倍图像中的纤维对齐情况。在像素较少的图像中，FTMA 算法的精度取决于图像特征的排列。与接近 0 或 ±90° 的特征相比，45° 的特征测量精度更高。为了解决这个问题，我们提出了一种新的 FTMA-MultiRotate 方法。这种修改后的算法已通过计算机生成的图像进行了评估，其平均精度可达到 ±0.5° 以内。随后，该算法被进一步应用于测量玻璃纤维织物低倍照片中的纤维排列，并与人工测量结果进行了验证。在 93% 的情况下，修改后的 FTMA-MultiRotate 算法与人工测量结果的一致性在 ±1.5° 范围内。Recyclable epoxy resins with different silyl ether structures: structure-property relationships and applications in diverse functional compositesYinqiao Liu, Mengna Wu, Qing Wen, Liying Zhang, Qiuran Jiang, Jun Wang, Wanshuang Liudoi:10.1016/j.compositesa.2024.108017 具有不同硅醚结构的可回收环氧树脂：结构-性能关系及在多种功能复合材料中的应用In this work, three liquid silyl ether-containing cycloaliphatic epoxides (CESI1, CESI2 and CESI3) with different numbers of pendent phenyl groups were synthesized and cured by methylhexahydrophthalic anhydride. The high glass transition temperatures of the cured epoxy resins range from 150 to 184 °C, which increase with the increasing number of pendent phenyl groups. However, the tensile strengths of the cured epoxy resins decrease as the number of pendent phenyl groups increase. Incorporating dynamic silyl ether bonds enables the cured epoxy resins to be reprocessable and degradable. It is demonstrated that the pendent phenyl groups have a significant impact on the dynamic behaviors and degradation rates of cured epoxy resins. The reprocessing efficiencies and degradation rates of the three epoxy resins monotonously decrease with increasing the number of pendent phenyl groups. Finally, the CESI1 resin with the lowest viscosity was used as the polymer matrix for carbon fiber reinforced composites, electromagnetic wave absorbing coatings and silver-filled conductive adhesives. Notably, non-destructive recovery of carbon fibers, ferromagnetic particles and silver flakes can be achieved through the degradation of the epoxy matrix.本研究合成了三种含有不同数量的苯基悬垂基的液态硅醚环脂环氧化物（CESI1、CESI2 和 CESI3），并用甲基六氢邻苯二甲酸酐进行固化。固化环氧树脂的玻璃化转变温度较高，在 150 至 184 ℃ 之间，且随悬垂苯基数的增加而升高。然而，固化环氧树脂的拉伸强度会随着悬垂苯基数的增加而降低。加入动态硅醚键可使固化环氧树脂具有可再加工性和可降解性。研究表明，下垂苯基基团对固化环氧树脂的动态行为和降解率有显著影响。三种环氧树脂的再加工效率和降解率随着悬垂苯基数的增加而单调降低。最后，粘度最低的 CESI1 树脂被用作碳纤维增强复合材料、电磁波吸收涂层和银填充导电胶的聚合物基体。值得注意的是，碳纤维、铁磁性颗粒和银薄片可通过环氧基质的降解实现无损回收。Composites Part B: EngineeringOne-dimensional deep convolutional autoencoder active infrared thermography: Enhanced visualization of internal defects in FRP compositesYubin Zhang, Changhang Xu, Pengqian Liu, Jing Xie, Yage Han, Rui Liu, Lina Chendoi:10.1016/j.compositesb.2024.111216一维深度卷积自动编码器主动红外热成像技术：增强玻璃钢复合材料内部缺陷的可视化Fiber-reinforced polymer (FRP) composites have been widely applied in different industrial fields, thereby necessitating the employment of non-destructive testing (NDT) methods to ensure structural integrity and safety. Active infrared thermography (AIRT) is a fast and cost-efficient NDT technique for inspecting FRP composites. However, this method is easily affected by factors such as inhomogeneous heating, leading to a low level of visualization of defects. To address this issue, this study proposes a novel method called one-dimensional deep convolutional autoencoder active infrared thermography (1D-DCAE-AIRT) to enhance the visualization of internal defects in FRP composites. This method first preprocesses the thermal image sequence acquired by AIRT inspections. Subsequently, high-level thermal features at the pixel level are extracted from the aforementioned preprocessed thermal image sequence using a designed one-dimensional deep convolutional autoencoder (1D-DCAE) model. Finally, the extracted high-level thermal features are employed to generate enhanced visualization results that exhibit improved defect visibility. The results of three kinds of AIRT (eddy current pulsed thermography, flash thermography, and vibrothermography) experiments on FRP composite specimens with artificially introduced defects show that 1D-DCAE-AIRT can effectively enhance the visualization of internal defects. The enhancement effect is better than the conventional techniques of fast Fourier transform (FFT), principal component analysis (PCA), independent component analysis (ICA), and partial least-squares regression (PLSR).纤维增强聚合物（FRP）复合材料已广泛应用于不同的工业领域，因此有必要采用无损检测（NDT）方法来确保结构的完整性和安全性。主动红外热成像（AIRT）是一种用于检测玻璃纤维增强塑料复合材料的快速、经济的无损检测技术。然而，这种方法很容易受到加热不均匀等因素的影响，导致缺陷的可视化程度较低。针对这一问题，本研究提出了一种名为一维深度卷积自动编码器主动红外热成像（1D-DCAE-AIRT）的新方法，以提高玻璃钢复合材料内部缺陷的可视化程度。该方法首先对 AIRT 检测获得的热图像序列进行预处理。然后，使用设计的一维深度卷积自动编码器（1D-DCAE）模型从上述预处理的热图像序列中提取像素级的高级热特征。最后，利用提取的高级热特征生成增强的可视化结果，从而提高缺陷的可见性。在人为引入缺陷的玻璃钢复合材料试样上进行的三种 AIRT（涡流脉冲热成像、闪光热成像和振动热成像）实验结果表明，1D-DCAE-AIRT 能有效增强内部缺陷的可视化。其增强效果优于快速傅立叶变换 (FFT)、主成分分析 (PCA)、独立成分分析 (ICA) 和偏最小二乘回归 (PLSR) 等传统技术。A novel thermoplastic water-soluble sizing agent for the interfacial enhancement of carbon fiber/polyether ether ketone compositesFei Yan, Tianwen Yan, Gaosong Wang, Gang Li, Shengtao Dai, Yuhui Ao, Jintang Duan, Liu Liudoi:10.1016/j.compositesb.2024.111205用于增强碳纤维/聚醚醚酮复合材料界面性能的新型热塑性水溶性施胶剂Recently reported novel water-soluble polyether ether ketone (PEEK) derivative sizing agents have garnered considerable attention for improving interfacial bonding of carbon fiber-reinforced PEEK (CF/PEEK) composites. However, their extensive application is somewhat limited due to two drawbacks: the use of hazardous organic solvents in production and the retention of emulsifiers in sizing dispersion systems. Herein, an extremely hydrophilic sulfonated PEEK with a cardo group (S-PEEK-WC) was synthesized and used to prepare a water-soluble sizing agent. The S-PEEK-WC exhibits excellent thermal stability, with a 5 % decomposition temperature of 446.5 °C, and its aqueous solution remains stable for over six months. A robust interphase was also constructed in the CF/PEEK composites through multiple physicochemical interactions. Compared with the de-sized CF/PEEK composites, the interlaminar shear strength, flexural strength and interfacial shear strength of the CF2/PEEK composites improved by 57.9 %, 56.3 % and 44.8 %, respectively. This approach may shed some light on the development of a valid and environmentally friendly method for preparing water-soluble sizing agents of polyaryletherketone.最近报道的新型水溶性聚醚醚酮（PEEK）衍生物施胶剂在改善碳纤维增强聚醚醚酮（CF/PEEK）复合材料的界面粘合方面引起了广泛关注。然而，由于在生产过程中使用有害的有机溶剂以及在施胶分散体系中保留乳化剂这两个缺点，它们的广泛应用受到了一定的限制。在此，我们合成了一种带有 Cardo 基团的极亲水性磺化聚醚醚酮（S-PEEK-WC），并将其用于制备水溶性施胶剂。S-PEEK-WC 具有出色的热稳定性，5%分解温度为 446.5 °C，其水溶液可保持稳定 6 个月以上。通过多种物理化学相互作用，CF/PEEK 复合材料中还形成了坚固的相间结构。与去尺寸的 CF/PEEK 复合材料相比，CF2/PEEK 复合材料的层间剪切强度、弯曲强度和界面剪切强度分别提高了 57.9%、56.3% 和 44.8%。这种方法有助于开发一种有效且环保的聚芳醚酮水溶性施胶剂制备方法。Full-field characterizations of additively manufactured composite cellular structuresAnil Singh, Behrad Koohbor, George Youssefdoi:10.1016/j.compositesb.2024.111208增材制造复合蜂窝结构的全场特性分析Honeycomb structures possess unique mechanical and structural behaviors, including high specific strength, superior energy absorption, and potential for multifunctionality. The advantages of such structures are bolstered by their realization through additive manufacturing, enabling cellular geometries beyond traditionally fabricated hexagons and facilitating a pathway for hybridization using composite materials to tune the response. This research synthesized photocurable particulate-reinforced resins using mechanically compliant matrix and glass microballoons reinforcement. The modified resins were used to additively manufacture lattice structures with circular and hexagonal unit cell geometries at different glass microballoons reinforcement weight ratios, ranging from neat to 20 wt%. The 3D printed structures were tested under quasi-static and impact loading scenarios to elucidate the interrelationships between the cell geometry, induced deformations, and strain rates. The mechanical testing was coupled with digital image correlation (DIC) to reveal the deformation-geometry interrelationship on the global (macroscale) and local (mesoscale) levels. The multiscale analyses allowed for extensive characterization of the effect of cell geometry and increased weight reinforcement on the mechanical response at a global, sub-cellular, and cellular level, i.e., elucidating the hierarchical dependency. The novelty leading to the current study stems from probing and revealing the deformation state of cellular structures subjected to two loading scenarios using DIC. This study intended to provide mechanistic insights for engineering lattice structures for impact mitigation applications by offering a viable approach to additive manufacturing composite materials.蜂窝结构具有独特的机械和结构特性，包括高比强度、卓越的能量吸收能力和多功能潜力。通过增材制造技术实现蜂窝状几何形状，超越了传统的六边形制造工艺，并为使用复合材料调整响应的混合途径提供了便利，从而增强了此类结构的优势。这项研究利用机械顺应性基体和玻璃微球增强材料合成了光固化微粒增强树脂。改性树脂用于以不同的玻璃微球增强重量比（从未加工到 20 wt%）添加制造具有圆形和六边形单元格几何形状的晶格结构。在准静态和冲击加载情况下对 3D 打印结构进行了测试，以阐明晶胞几何形状、诱导变形和应变率之间的相互关系。机械测试与数字图像相关性（DIC）相结合，揭示了全局（宏观尺度）和局部（中观尺度）层面的变形-几何相互关系。通过多尺度分析，可以从全局、亚细胞和细胞层面广泛描述细胞几何形状和增重加固对机械响应的影响，即阐明分层依赖关系。本研究的新颖之处在于利用 DIC 探测和揭示了细胞结构在两种加载情况下的变形状态。这项研究旨在为工程晶格结构的冲击缓解应用提供机理见解，为增材制造复合材料提供一种可行的方法。‘Resin welding’: A novel route to joining acrylic composite components at room temperatureMachar Devine, Ankur Bajpai, Conchúr M. Ó Brádaigh, Dipa Raydoi:10.1016/j.compositesb.2024.111212树脂焊接"：在室温下连接丙烯酸复合材料部件的新方法The solubility of acrylic polymer in its own liquid monomer creates the opportunity to ‘weld’ acrylic-matrix (Elium®) composites without the application of heat. In this method, termed resin welding, acrylic monomeric resin is infused between acrylic-matrix composite parts. The resin dissolves and diffuses into the acrylic matrix and creates a continuous material, and a strong bond, when it polymerises, without the sensitivities of traditional welding methods to adherend or bondline thickness. Single lap shear testing was conducted on resin-welded and adhesively-bonded coupons with varying bondline thicknesses and filling fibres, and the bonding and fracture mechanisms were investigated using SEM and the diffusion of dyed acrylic resin. The highest bond strength of resin-welded coupons reached 27.9 MPa, which is 24 % higher than the strongest weld reported in the literature, indicating that resin welding is a promising alternative to traditional bonding and welding methods for acrylic-matrix composites.丙烯酸聚合物在自身液态单体中的溶解性为无需加热即可 "焊接 "丙烯酸基质 (Elium®) 复合材料创造了机会。在这种称为树脂焊接的方法中，丙烯酸单体树脂被注入丙烯酸基复合材料部件之间。树脂溶解并扩散到丙烯酸基体中，聚合后形成连续的材料和牢固的粘合，而不会像传统焊接方法那样对粘合剂或粘合线厚度产生影响。对具有不同粘合剂厚度和填充纤维的树脂焊接和粘合剂粘合试样进行了单搭接剪切测试，并利用扫描电镜和染色丙烯酸树脂的扩散研究了粘合和断裂机制。树脂焊接试样的最高粘接强度达到 27.9 兆帕，比文献报道的最强焊缝高出 24%，表明树脂焊接是丙烯酸基复合材料传统粘接和焊接方法的一种很有前途的替代方法。Investigation on moisture absorption behavior on GFRP and neat epoxy systems in hygrothermal salt fog agingGeovane de Almeida Santos da Silva, José Roberto Moraes d’Almeida, Daniel Carlos Taissum Cardosodoi:10.1016/j.compositesb.2024.111214研究湿热盐雾老化过程中 GFRP 和纯环氧系统的吸湿行为This work investigates the moisture absorption behavior in epoxy matrix composites reinforced with glass fibers, used in repairs of offshore topside metal pipelines exposed to aging in saline environment. The materials used were a bicomponent DGEBA epoxy and a woven bidirectional E-glass fabric. In order to simulate the harsh environment, the composites were exposed to accelerated hygrothermal aging tests in three independent salt spray chambers at temperatures of 35, 55 and 70 °C and the materials had their mass gain monitored. The moisture absorption of the neat epoxy resin was also investigated and correlated with that of the composites. Thermal analyses by Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Thermal Analysis (DMTA) were performed to evaluate the curing state of the polymeric materials tested and the effects of temperature on the material's post-curing. Fourier-Transform Infrared (FTIR) analyses were performed to investigate the occurrence of post-curing, hydrolysis and thermo-oxidation processes during aging. As expected, it was seen that temperature increased diffusivity for both the composite and the unreinforced epoxy matrix. The neat epoxy resin presented a decrease in moisture absorbed with temperature, evidencing the effect of post-curing on moisture absorption. Furthermore, from the thermal analyses, it was observed the presence of an interphase between matrix and fibers with a Tg higher than the bulk matrix. Non-Fickian models confirmed structural changes caused by temperature and moisture in the materials. A modification of the Berens-Hopfenberg (BH) non-Fickian model was proposed to account for post-curing effects on moisture absorption.这项研究调查了玻璃纤维增强环氧基复合材料的吸湿行为，该复合材料用于修复暴露在盐碱环境中老化的近海上层金属管道。所用材料为双组分 DGEBA 环氧树脂和双向 E 型玻璃纤维编织物。为了模拟恶劣的环境，复合材料在 35、55 和 70 °C 三个独立盐雾箱中进行了加速湿热老化试验，并对材料的增重进行了监测。此外，还研究了纯环氧树脂的吸湿性，并将其与复合材料的吸湿性进行了对比。通过差示扫描量热法（DSC）和动态机械热分析法（DMTA）进行了热分析，以评估受测聚合物材料的固化状态以及温度对材料后固化的影响。傅立叶变换红外（FTIR）分析用于研究老化过程中发生的后固化、水解和热氧化过程。不出所料，复合材料和未增强环氧基质的扩散率都会增加。纯环氧树脂的吸湿率随温度升高而降低，这证明了后固化对吸湿率的影响。此外，从热分析中还观察到基体和纤维之间存在一个间相，其 Tg 高于块状基体。非菲克模型证实了温度和湿气在材料中引起的结构变化。对贝伦斯-霍普芬伯格（BH）非费克模型进行了修改，以考虑固化后对吸湿性的影响。Composites Science and TechnologyEfficient electromagnetic wave absorption of polypyrrole/low-reduction graphene oxide composites through dielectric properties modulationHuan Zhang, Nian Luo, Tinglong Liu, Yu Wang, Feng Chen, Qiang Fudoi:10.1016/j.compscitech.2024.110436 通过介电性能调制实现聚吡咯/低还原氧化石墨烯复合材料的高效电磁波吸收Graphene oxide (GO) is widely used in electromagnetic microwave absorption (EMA) materials due to its abundant oxygen-containing functional groups and defects. Its conductivity, surface functional groups and defect density can be modified by controlling reduction degree to modulate its electromagnetic properties. However, the thermal reduction temperature needed is often too high, exceeding the Curie temperature of magnetic materials, which makes further compounding difficult. Polypyrrole (PPy), as a conductive polymer with high electrical conductivity, is widely used in EMA field and can help regulate the dielectric properties of materials. In this paper, a series of PPy/GO composites with different ratios and reduction degrees were prepared by in situ polymerization and thermal reduction, and their EMA properties were investigated. At a loading amount of 7.5 wt%, the maximum reflection loss of PPy/rGO composites can reach −66.64 dB, and the effective absorption bandwidth can reach 6.74 GHz with a reduction temperature of only 400 °C. Furthermore, the unreduced sample also has excellent absorption performance, which has a wide range of applications for future one-step compositing with magnetic materials in low reduction temperature.氧化石墨烯（GO）因其丰富的含氧官能团和缺陷而被广泛应用于电磁微波吸收（EMA）材料。通过控制还原度可以改变石墨烯的导电性、表面官能团和缺陷密度，从而调节其电磁特性。然而，所需的热还原温度往往过高，超过了磁性材料的居里温度，这给进一步的复合带来了困难。聚吡咯（PPy）作为一种导电性聚合物，具有很高的导电性，被广泛应用于 EMA 领域，有助于调节材料的介电性能。本文通过原位聚合和热还原的方法制备了一系列不同配比和还原度的 PPy/GO 复合材料，并对其 EMA 性能进行了研究。在负载量为 7.5 wt% 时，PPy/rGO 复合材料的最大反射损耗可达 -66.64 dB，有效吸收带宽可达 6.74 GHz，还原温度仅为 400 ℃。此外，未还原样品也具有优异的吸收性能，这对于未来在低还原温度下与磁性材料一步复合具有广泛的应用前景。Thermo-oxidative aging induced multi-scale shrinkages and damages in 3D angle-interlock woven compositesYanan Ke, Shuwei Huang, Baozhong Sun, Frank Ko, Bohong Gudoi:10.1016/j.compscitech.2024.110438 三维角交错编织复合材料的热氧化老化诱导多尺度收缩和损伤The deterioration of resin and interface in composites deteriorate during high-temperature service, would impact both the thermal stability and overall performance significantly. This paper focused on the experimental characterization of multi-scale damage and resin shrinkage within composites induced by thermo-oxidative aging using Micro-CT, SEM and Confocal Interferometric Microscopy (CIM), and exploring the coupling mechanism between them. The results show that damage distribution and propagation are affected by the hierarchical structure of 3-D angle-interlock fabric. Macro-CIM shows that maximum resin shrinkage depth depends on the resin width and aging time. Resin shrinkage profile evolution demonstrated the accelerating effect of resin crack on shrinkage. Micro-CIM shows that macro yarn cracks form through the accumulation of micro resin cracks in resin-rich areas and fiber/resin interface debonding. The formation of fiber/resin interface crack is tied to the resin shrinkage state, only occurring when the surrounding resin shrinkage slope exceeds a specific threshold value.在高温服役期间，复合材料中树脂和界面的劣化会严重影响其热稳定性和整体性能。本文重点利用显微 CT、扫描电镜和共聚焦干涉显微镜（CIM）对热氧化老化诱导的复合材料内部多尺度损伤和树脂收缩进行了实验表征，并探讨了它们之间的耦合机制。结果表明，损伤分布和传播受三维角交错织物分层结构的影响。宏观 CIM 显示，最大树脂收缩深度取决于树脂宽度和老化时间。树脂收缩曲线的演变证明了树脂裂纹对收缩的加速效应。微观-CIM 显示，宏观纱线裂纹是通过树脂富集区的微观树脂裂纹累积和纤维/树脂界面脱粘形成的。纤维/树脂界面裂纹的形成与树脂收缩状态有关，只有当周围树脂收缩斜率超过特定临界值时才会出现。来源：复合材料力学仿真Composites FEM