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【新文速递】2024年1月4日复合材料SCI期刊最新文章

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

Composite Structures

CONFINEMENT OF MASONRY WITH FRCM COMPOSITES: STRENGTH PREDICTIVE MODELS

Annalisa Napoli, Roberto Realfonzo

doi:10.1016/j.compstruct.2023.117864

用 FRCM 复合材料对砌体进行约束:强度预测模型

Fabric reinforced cementitious matrix (FRCM) composites have emerged as an appealing alternative to fiber reinforced polymer (FRP) for the external confinement of masonry members; nevertheless, their use in practice is limited due to the lack of reliable formulas to estimate the compressive strength and ultimate strain of confined members. By following a recently published study, new formulas for the prediction of the compressive strength of the FRCM confined masonry are proposed here, which were obtained by considering an updated experimental database compiled from the literature. These formulas were developed by applying error minimization techniques to the collected experimental results; test data were treated in different ways, such as: a) separating the members made of natural stones from those built with artificial blocks, and b) treating separately the fiber types (basalt, carbon, glass, PBO and steel) of the FRCM system, or c) considering the experimental data all together. Finally, to evaluate the reliability of the developed relationships, the strength predictions provided by the new proposals were compared with those obtained using the expressions reported in some international guidelines.

织物增强水泥基复合材料(FRCM)已成为纤维增强聚合物(FRP)的替代品,可用于砌体的外部约束;然而,由于缺乏可靠的公式来估算约束构件的抗压强度和极限应变,它们在实践中的应用受到了限制。根据最近发表的一项研究,本文提出了用于预测 FRCM 封闭砌体抗压强度的新公式,这些公式是通过考虑文献中汇编的最新实验数据库而获得的。这些公式是通过对收集到的实验结果应用误差最小化技术而得出的;测试数据采用了不同的处理方式,例如:a) 将天然石块和人工砌块制成的构件分开处理;b) 将 FRCM 系统的纤维类型(玄武岩、碳、玻璃、PBO 和钢)分开处理;或者 c) 将所有实验数据放在一起考虑。最后,为了评估所建立关系的可靠性,将新建议提供的强度预测值与使用一些国际指南中报告的表达式获得的强度预测值进行了比较。


Composites Part A: Applied Science and Manufacturing

The effect of fibre misalignment in an impregnated fibre bundle on stress concentrations

M. Jafarypouria, S.V. Lomov, Biltu Mahato, S.G. Abaimov

doi:10.1016/j.compositesa.2023.108001

浸渍纤维束中纤维错位对应力集中的影响

This work investigates the stress redistribution around a broken fibre in a unidirectional impregnated fibre bundle accounting for misalignment of fibres. The study reveals, a statistically significant increase in stress concentration factor (SCF) within misaligned bundles. The effect of fibre misalignment is more pronounced for high fibre volume fraction (VF) and for the nearest neighbour fibres (NNFs) to the broken one. The peak of the SCF graphs shows a significant increase about 16%, 33%, and 55% for VF30%, VF50%, and VF60%, respectively. This implies that the influence of fibre misalignment is more localised, resulting in stronger SCF in the NNFs. Ineffective lengths at applied strain 2% do not change in the case of fibre misalignment in comparison with the case of aligned fibres. This is linked to matrix yielding, as at applied strain 0.1% the ineffective length increases for the misaligned case by 12-30%, depending of fibre volume fraction.

这项研究探讨了单向浸渍纤维束中断裂纤维周围的应力再分布,并考虑了纤维错位的情况。研究发现,在错位纤维束中,应力集中系数(SCF)在统计学上有显著增加。纤维错位对高纤维体积分数(VF)和断裂纤维的近邻纤维(NNF)的影响更为明显。在 VF30%、VF50% 和 VF60% 时,SCF 图形的峰值分别显著增加了约 16%、33% 和 55%。这意味着纤维错位的影响更加局部化,导致 NNF 的 SCF 更强。与纤维对齐的情况相比,纤维错位情况下施加应变 2% 时的无效长度没有变化。这与基体屈服有关,因为在施加应变 0.1% 时,错位情况下的无效长度增加了 12-30%,具体取决于纤维的体积分数。


Composites Part B: Engineering

Tailoring nanostructured MXene to adjust its dispersibility in conductive hydrogel for self-powered sensors

Yaoxun Zhang, Jian Zou, Shengji Wang, Xiangshu Hu, Zihao Liu, Peiyong Feng, Xin Jing, Yuejun Liu

doi:10.1016/j.compositesb.2024.111191

定制纳米结构 MXene 以调整其在导电水凝胶中的分散性,用于自供电传感器

MXenes are ideal conductive fillers to construct conductive routes for hydrogel-based flexible sensors owing to their great metallic conductivity, hydrophilicity, and high specific surface area. However, their high tendency to aggregate in sol solution severely limited the performance of the resultant hydrogels. Therefore, to enhance the performance of MXene-filled composite hydrogels, we proposed an oxidization method to tailor the nanostructure of MXene to improve the conductivity, transparency, mechanical properties, and sensitivity of the composite hydrogels. Meanwhile, it is noted that the conductivity of the hydrogel significantly affected the output performance of hydrogel-based triboelectric nanogenerator (H-TENG). The polyacrylamide/oxidized MXene (POM) hydrogel-based TENG with the highest output performance was assembled for self-powered sensing and energy harvesting, which demonstrated great reliability and durability with a maximum open circuit voltage of 243 V and a peak power density of 2.38 W/m2. Moreover, the relationship model between the conductivity of the hydrogel and the output performance of the H-TENG was successfully proposed based on the performance of the developed H-TENGs. Therefore, this work shed lights for reasonable design of H-TENGs with high output performance.

二甲氧烯类具有极强的金属导电性、亲水性和高比表面积,是构建基于水凝胶的柔性传感器导电路径的理想导电填料。然而,它们在溶胶溶液中的高聚集倾向严重限制了生成的水凝胶的性能。因此,为了提高 MXene 填充复合水凝胶的性能,我们提出了一种氧化方法来定制 MXene 的纳米结构,从而提高复合水凝胶的导电性、透明度、机械性能和灵敏度。同时,我们注意到水凝胶的电导率会显著影响水凝胶基三电纳米发电机(H-TENG)的输出性能。研究人员组装了输出性能最高的聚丙烯酰胺/氧化二甲苯(POM)水凝胶基三电纳米发电机,用于自供电传感和能量收集,其最大开路电压为 243 V,峰值功率密度为 2.38 W/m2,表现出极高的可靠性和耐用性。此外,根据所开发 H-TENG 的性能,成功地提出了水凝胶电导率与 H-TENG 输出性能之间的关系模型。因此,这项工作为合理设计具有高输出性能的 H-TENG 提供了启示。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystem断裂复合材料电路UM电机Electric材料
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首次发布时间:2024-11-05
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【新文速递】2024年1月9日复合材料SCI期刊最新文章

今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 1 篇Composite StructuresEffective Magnetoelastic Responses of Hybrid fiber Composites with Viscoelastic MatricesChien-hong Lin, Chia-Ju Lindoi:10.1016/j.compstruct.2024.117874带粘弹性基材的混合纤维复合材料的有效磁弹性响应This study examines the overall magnetoelastic responses of unidirectional fiber composites constructed by magnetostrictive fibers embedded in viscoelastic polymer matrices that had been reinforced by stiff fillers. In some polymer-based fiber composites, modifying polymer’s property by infiltrating particulate fillers is necessary. To design such hybrid composite systems with magnetoelastic coupling, it requires a detailed understanding of aggregate responses. In this study, we formulate a composite constitutive model based on a two-scale homogenization scheme for effective coupled viscoelastic and magnetoelastic responses for hybrid fiber composites. We first verify the validity of the model by comparing the predictions with experimental results available in literatures. We next investigate the performance of a hybrid composite in light of blocked stress and free strain which are two common factors of characterizing sensors and actuators. We finally elucidate how viscoelastic polymer matrices affect the overall magnetoelastic responses and ΔE-effect phenomenon in terms of some critical parameters such as phase concentrations, loading rates, prestresses and temperatures. The findings of this study serve as a preliminary guidance for the rational design of hybrid magnetostrictive composite materials. The proposed mathematics model can further integrate into a finite element framework for composite structure analysis.本研究探讨了单向纤维复合材料的整体磁弹性响应,该复合材料由嵌入粘弹性聚合物基体中的磁致伸缩纤维构成,基体由硬质填料增强。在某些聚合物基纤维复合材料中,有必要通过渗入颗粒填料来改变聚合物的特性。要设计这种具有磁弹性耦合的混合复合材料系统,需要详细了解骨料的反应。在本研究中,我们基于双尺度均质化方案,为混合纤维复合材料的有效耦合粘弹性和磁弹性响应建立了一个复合材料构成模型。我们首先将预测结果与文献中的实验结果进行比较,验证模型的有效性。接下来,我们根据阻塞应力和自由应变这两个表征传感器和致动器的常见因素来研究混合复合材料的性能。最后,我们阐明了粘弹性聚合物基体如何在相浓度、加载速率、预应力和温度等关键参数方面影响整体磁弹性响应和 ΔE 效应现象。本研究的结果为合理设计混合磁致伸缩复合材料提供了初步指导。所提出的数学模型可进一步集成到复合材料结构分析的有限元框架中。Physics-Guided Deep Learning for Damage Detection in CFRP Composite StructuresXuebing Xu, Cheng Liudoi:10.1016/j.compstruct.2024.117889物理引导的深度学习用于 CFRP 复合材料结构的损伤检测Structural health monitoring of carbon fiber reinforced plastics composite structures based on deep learning usually builds on black box models for damage detection. However, the lack of physics knowledge limits its application into real-world problems where structural property or environmental condition varies. To overcome this limitation, we propose a physics-guided deep learning framework to integrate physics into data-driven models. This physics-guided convolutional neural network leverages structural degradation trend and physical consistency by combining the output of the physical model with the observed feature in a hybrid model. This hybrid model uses an additional branch to observe the information of stiffness degradation, which is the input into the physical model to describe the damage growth in structures by establishing a relationship with the power spectral density change in the guided wave signals. Additionally, the physics-based loss function is designed as part of the learning objective to ensure the model outputs satisfy the existing physics and maintain physical consistency. Experiment results show that our method demonstrates great generalizability that by training on data of only one particular CFRP composite structure, the PGCNN model can expand its great performance on all other CFRP layups in the NASA-published CFRP Dataset with over 90% accuracy.基于深度学习的碳纤维增强塑料复合结构的结构健康监测通常建立在黑盒模型的基础上进行损伤检测。然而,物理知识的缺乏限制了其在结构特性或环境条件变化的实际问题中的应用。为了克服这一局限,我们提出了一种物理引导的深度学习框架,将物理知识整合到数据驱动的模型中。这种物理引导的卷积神经网络通过将物理模型的输出与混合模型中的观测特征相结合,充分利用了结构退化趋势和物理一致性。该混合模型使用额外的分支来观察刚度退化信息,并将其输入物理模型,通过与导波信号的功率谱密度变化建立联系来描述结构的损伤增长。此外,还设计了基于物理的损失函数,作为学习目标的一部分,以确保模型输出满足现有物理条件并保持物理一致性。实验结果表明,我们的方法具有很强的普适性,只需在一个特定 CFRP 复合材料结构的数据上进行训练,PGCNN 模型就能在 NASA 发布的 CFRP 数据集中的所有其他 CFRP 层状结构上扩展其卓越性能,准确率超过 90%。Tension-tension fatigue properties of multiaxial laminated carbon/epoxy composites molded by high-pressure resin transfer molding (HP-RTM) processSARKER Sagar, QIN Xiaohong, YU Bing, MA Heshan, YANG Yuqiu, GAO Congdoi:10.1016/j.compstruct.2024.117892采用高压树脂传递模塑(HP-RTM)工艺成型的多轴层压碳/环氧复合材料的拉伸疲劳特性Engineering structures are often subjected to cyclic-loading conditions, which detrimentally affect the component’s service life and damage tolerance. The fatigue behavior of multiaxial laminated composites manufactured with unidirectional plies has been analyzed. Carbon/epoxy composite laminate was molded by a high-pressure resin transfer molding (HP-RTM) process. Specimens were subjected to tension-tension (T-T) fatigue stress of 65%-75% of static tensile strength until failure or up to one million cycles. An analysis of the maximum stress-cycle number (S-N) curve is conducted to determine the fatigue limits of the material. The predetermined fatigue limit has been obtained at 717.5 MPa stress, which is about 67% of static tensile strength under tension-tension stress conditions. Fatigue failures under tension-tension loading conditions are associated with fiber breakage, fiber pull-out, and plies delamination. This research aimed to understand the fatigue behavior and fracture mechanism of multiaxial laminated composites under tension-tension cyclic loading conditions and collect more data for future research.工程结构经常会受到循环加载条件的影响,从而对部件的使用寿命和损伤容限产生不利影响。本文分析了使用单向层制造的多轴层压复合材料的疲劳行为。碳/环氧复合材料层压板采用高压树脂传递模塑(HP-RTM)工艺成型。试样经受静态拉伸强度 65%-75% 的拉伸-拉伸(T-T)疲劳应力,直至失效或达到一百万次循环。对最大应力-循环次数(S-N)曲线进行分析,以确定材料的疲劳极限。预设的疲劳极限为 717.5 兆帕应力,约为拉伸应力条件下静态抗拉强度的 67%。拉伸-张力加载条件下的疲劳失效与纤维断裂、纤维拉出和层间分层有关。本研究旨在了解多轴层压复合材料在拉伸-张力循环加载条件下的疲劳行为和断裂机理,并为今后的研究收集更多数据。Composites Part A: Applied Science and ManufacturingNumerical investigation of two-dimensional Mode-II delamination in composite laminatesCongzhe Wang., Anastasios P. Vassilopoulos., Thomas Kellerdoi:10.1016/j.compositesa.2024.108012复合材料层压板中二维模式 II 分层的数值研究Existing standards for delamination tests on composite materials typically employ one-dimensional (1D) beam specimens. However, such specimens may not represent real delamination scenarios in composite structures, where cracks tend to propagate in two dimensions. To address this limitation and compare the delamination behavior under both 1D and two-dimensional (2D) Mode-II fracture conditions, a numerical investigation was carried out based on previous experiments. A novel cohesive zone model, considering both microcracking and fiber bridging within the fracture process zone, was developed using a semi-experimental approach and incorporated in three-dimensional finite element simulations. According to the numerical results, the investigated laminates exhibited similar maximum strain energy release rates in both 1D and 2D delamination; however, different traction-separation responses were obtained. Practical methods of locating the tip of an embedded crack were proposed based on curvature and strain measurements on the laminate surface, demonstrating potential for application in structures with irregular crack shapes.复合材料分层测试的现有标准通常采用一维(1D)梁试样。然而,这种试样可能无法代表复合材料结构中的真实分层情况,因为复合材料结构中的裂纹往往会在二维范围内扩展。为了解决这一局限性,并比较一维和二维 (2D) 模式 II 断裂条件下的分层行为,我们在之前实验的基础上进行了数值研究。采用半实验方法开发了一种考虑到断裂过程区内微裂纹和纤维桥接的新型内聚区模型,并将其纳入三维有限元模拟中。数值结果表明,所研究的层压板在一维和二维分层中表现出相似的最大应变能释放率,但却获得了不同的牵引分离响应。根据层压板表面的曲率和应变测量结果,提出了定位嵌入裂纹尖端的实用方法,显示了在具有不规则裂纹形状的结构中的应用潜力。来源:复合材料力学仿真Composites FEM

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