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【新文速递】2024年3月30日复合材料SCI期刊最新文章

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今日更新:Composite Structures 6 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 2 篇

Composite Structures

Nonlinear stochastic behavior of soft-core sandwich panels

N. Malkiel, O. Rabinovitch

doi:10.1016/j.compstruct.2024.118085

软芯夹芯板的非线性随机行为

The nonlinear stochastic behavior of soft-core sandwich panels and the evolution of uncertainty along the nonlinear path are investigated. The paper focuses on the way the geometrically nonlinear and unstable behavior is affected by uncertainty and considers, for the first time, the evolution of uncertainty along the unstable structural response. The structural modeling relies on the EHSAPT and its integration into the geometrically nonlinear stochastic regime. A tailored nonlinear FE model that is based on a variational formulation and an arc-length solution scheme are developed. The stochastic analysis adopts the Perturbation-based SFEM and its generalization for the evolution of uncertainty along the process axis. A numerical study demonstrates the stochastic methodology and explores the impact of uncertainty on the nonlinear structural behavior. The evolution of the stochastic stress resultants at the displaced end is studied along the two axes of evolution. The differences between the two representations and their physical and engineering significance are highlighted revealing significant changes to the uncertainty evolution pattern with the shift from global buckling to localized wrinkling instabilities. The representation of the stochastic results along the process axis also quantifies the level of uncertainty near critical and singular points where conventional analyses diverge.

本文研究了软芯夹芯板的非线性随机行为以及不确定性沿非线性路径的演变。论文重点研究了几何非线性和不稳定行为受不确定性影响的方式,并首次考虑了不确定性沿不稳定结构响应的演变。结构建模依赖于 EHSAPT 及其与几何非线性随机机制的整合。基于变分公式和弧长求解方案,开发了一个量身定制的非线性 FE 模型。随机分析采用了基于扰动的 SFEM 及其广义方法,用于分析不确定性沿过程轴的演变。数值研究展示了随机方法,并探讨了不确定性对非线性结构行为的影响。沿两个演化轴研究了位移端随机应力结果的演化。研究强调了两种表示方法之间的差异及其物理和工程意义,揭示了不确定性演变模式从整体屈曲向局部起皱不稳定性转变过程中的显著变化。沿过程轴的随机结果表示法还量化了临界点和奇异点附近的不确定性水平,在这些地方,传统的分析会出现偏差。


Introducing a novel piezoelectric-based tunable design for mode-localized mass micro-sensors

Hossein Ali Alam-Hakkakan, Amir Reza Askari, Masoud Tahani

doi:10.1016/j.compstruct.2024.118086

为模式定位质量微型传感器引入基于压电的新型可调设计

This investigation focuses on developing a new sensitivity-improving approach for high-order mode-localized mass micro-sensors by utilizing the capabilities of piezoelectric materials. To this end, an electrostatically coupled micro-beam as the building block of MEMS mass sensors is considered. The present design includes the incorporation of a patterned arrangement of piezoelectric thin films placed on the lower electrode of the system. The nonlinear reduced equations of motion for the introduced tunable system are derived by employing the Hamilton principle in conjunction with the Euler-Bernoulli beam theory and the Ritz discretization procedure. These equations are subsequently solved using the harmonic balance method. The present findings are validated by those available in the literature for the case of static excitation. In addition, the eigenvalue loci of the proposed system have been compared and verified by those obtained through three-dimensional finite element simulations carried out in COMSOL Multiphysics commercial software. Taking the shift of the amplitude ratio as the measure demonstrating the sensitivity of the proposed design, it is observed that incorporating piezoelectric excitation can significantly enhance the efficiency of these systems more than two times in comparison to conventional mode-localized mass micro-sensors without piezoelectric layers.

本研究的重点是利用压电材料的功能,为高阶模式定位质量微传感器开发一种新的灵敏度改进方法。为此,我们考虑采用静电耦合微梁作为 MEMS 质量传感器的构件。本设计包括将压电薄膜图案化布置在系统的下电极上。通过结合使用汉密尔顿原理、欧拉-伯努利梁理论和里兹离散化程序,得出了引入的可调系统的非线性还原运动方程。这些方程随后用谐波平衡法求解。目前的研究结果与文献中关于静态激励情况的研究结果相吻合。此外,通过 COMSOL Multiphysics 商业软件进行的三维有限元模拟得到的特征值位置也与所提出系统的特征值位置进行了比较和验证。以振幅比的偏移量来衡量拟议设计的灵敏度,可以发现,与不带压电层的传统模式定位质量微传感器相比,加入压电激励可显著提高这些系统的效率两倍以上。


WrapToR shells: Concept introduction, experimental testing, and design space exploration

Chris F. Grace, Mark Schenk, Benjamin K.S. Woods

doi:10.1016/j.compstruct.2024.118089

WrapToR 外壳:概念介绍、实验测试和设计空间探索

This work introduces a novel truss stiffener concept for lightweight structural panels as an alternative to sandwich panels or stringer stiffened panels. The Wrapped Tow Reinforced (WrapToR) truss concept is modified to create stiffened composite panel structures (referred to here as WrapToR Shells). A prototype WrapToR Shell unit cell is manufactured and tested under three-point bending, where it demonstrates high levels of specific stiffness and strength. This experimental result is benchmarked against idealised sandwich panels via a low fidelity comparative analysis, and the study shows that even a best-case sandwich panel of equivalent mass under a representative bending load has an 83% increase in displacement, highlighting the excellent stiffness truss reinforced panels can provide. The design space available to the truss reinforced panels is then explored using finite element analysis and a simple parameter sweep of key truss design variables. A Pareto frontier between the competing objectives of minimising mass and maximising rigidity is shown, and global trends in performance are highlighted. It is observed that increasing the size of the truss profile or longitudinal member has a near linear increase on EI/mass, whereas for increasing shear member angle the inverse is true. For increasing shear member diameter, a less obvious effect on EI/mass is seen, indicating a more complex relationship with the other design variables.

这项研究为轻质结构板材引入了一种新颖的桁架加劲概念,以替代夹芯板或钢绞线加劲板。对缠绕缆索加固(WrapToR)桁架概念进行了修改,以创建加劲复合板结构(此处称为 WrapToR Shells)。WrapToR Shell 单元尺寸原型已制造完成,并在三点弯曲下进行了测试,显示出较高的特定刚度和强度。实验结果通过低保真对比分析与理想的夹层板进行了比较,研究表明,即使是同等质量的最佳夹层板,在代表性弯曲载荷下的位移也增加了 83%,这凸显了桁架加固板可提供的出色刚度。然后,利用有限元分析和关键桁架设计变量的简单参数扫描,探索了桁架加固板的设计空间。显示了质量最小化和刚度最大化这两个相互竞争的目标之间的帕累托前沿,并强调了性能方面的全球趋势。据观察,增加桁架轮廓或纵向构件的尺寸对 EI/质量有近乎线性的增加,而增加剪力构件角度则相反。增加剪力构件直径对 EI/质量的影响并不明显,这表明与其他设计变量的关系更为复杂。


Passively morphing trailing edge design for composite tidal turbine blades

James.M. Maguire, Dimitrios Mamalis, Shūji Ōtomo, Edward D. McCarthy

doi:10.1016/j.compstruct.2024.118090

复合材料潮汐涡轮机叶片的被动变形后缘设计

Numerical simulations and lab-scale experiments are used to evaluate three passively morphing trailing edge designs for a composite tidal turbine blade. The designs include a closed trailing edge, an open trailing edge, and a corrugated trailing edge. It is shown that geometric stiffness, as well as material stiffness, play key roles in achieving the desired deformation of the trailing edge. One trailing edge design is down-selected for further investigation via full-scale numerical simulations. These simulations demonstrate how the composite lay-up influences the morphing response of the trailing edge and its likelihood of material failure. The influence of camber is also investigated in terms of both material behaviour and hydrodynamic performance. Finally, the potential for bend-twist coupling of the laminate skins is explored.

通过数值模拟和实验室规模的实验,对复合材料潮汐涡轮叶片的三种被动变形后缘设计进行了评估。这些设计包括封闭式后缘、开放式后缘和波纹式后缘。结果表明,几何刚度和材料刚度在实现所需的后缘变形中起着关键作用。通过全尺寸数值模拟,最终选择了一种后缘设计进行进一步研究。模拟结果表明了复合材料铺层如何影响后缘的变形响应及其材料失效的可能性。此外,还研究了外倾角对材料性能和流体力学性能的影响。最后,还探讨了层压蒙皮弯曲-扭转耦合的可能性。


Micromechanical modeling for longitudinal tensile property of unidirectional CFRP considering dispersion of fiber properties

Hao Wang, Xiang-Yu Zhong, He Jia, Lian-Wang Zhang, Han-Song Liu, Ming-Chen Sun, Tian-Wei Liu, Jiang-Bo Bai, Si-Cheng Ge, Jian-Wen Bao

doi:10.1016/j.compstruct.2024.118081

考虑纤维分散特性的单向 CFRP 纵向拉伸性能微观力学模型

Longitudinal tensile failure prediction has always been the focus of research on unidirectional (UD) Carbon Fiber Reinforced Polymer (CFRP). In this paper, the longitudinal tensile tests of unidirectional T800 grade carbon fiber reinforced epoxy resin composite were carried out first. The experimental stress–strain curves show that there are obvious progressive damages before the final failures of the specimens. However, this phenomenon is usually neglected in most of the existing investigations and tests to only obtain elastic modulus and ultimate strength. Thus, a Representative Volume Element (RVE) model based on micromechanics was established using finite element method, considering the randomness of fiber spatial distribution and fiber strength. The tensile strength of fiber monofilaments was assumed to follow a statistical two-parameter Weibull distribution. The failure process of UD composite under longitudinal tensile load was simulated by explicit finite element method. The stress–strain curves obtained by simulation are in good agreement with the experimental results. Finally, the influence of different boundary conditions on the calculation of the RVE was studied. It is found that the final failure strengths of the RVE with uniform displacement boundary conditions are similar to the case of periodic boundary conditions, while the former has higher computational efficiency.

纵向拉伸失效预测一直是单向(UD)碳纤维增强聚合物(CFRP)的研究重点。本文首先对单向 T800 级碳纤维增强环氧树脂复合材料进行了纵向拉伸试验。实验应力-应变曲线显示,试样在最终失效前存在明显的渐进式损伤。然而,在现有的大多数研究和测试中,这种现象通常被忽略,而只获得弹性模量和极限强度。因此,考虑到纤维空间分布和纤维强度的随机性,采用有限元方法建立了基于微观力学的代表体积元素(RVE)模型。假设纤维单丝的拉伸强度遵循统计上的双参数威布尔分布。采用显式有限元法模拟了 UD 复合材料在纵向拉伸载荷作用下的破坏过程。模拟得到的应力-应变曲线与实验结果十分吻合。最后,研究了不同边界条件对 RVE 计算的影响。结果发现,采用均匀位移边界条件的 RVE 的最终破坏强度与采用周期边界条件的情况相似,而前者的计算效率更高。


In-situ failure behavior and interfacial bonding of an interpenetrating metal matrix composite reinforced with lattice-like metallic glass (Ni60Nb20Ta20) preform

Kerstin Dittmann, Robert Gruhl, Anna Trauth, Kay André Weidenmann

doi:10.1016/j.compstruct.2024.118084

用晶格状金属玻璃(Ni60Nb20Ta20)预制件增强的互穿金属基复合材料的原位破坏行为和界面粘接性

Metallic glasses (MG) have an amorphous atomic structure and exhibit several exceptional properties such as high strength, hardness associated with high elastic strain limit and elastic energy storage. But MGs are also prone to brittle fracture, making them difficult to use as monolithic structural components and might better be used as a reinforcement phase in hybrid composites such as metal matrix composites (MMC). The failure behavior of composites depends on the structure of the reinforcement phase. In this work, the failure behavior of an interpenetrating MMC reinforced with a MG (Ni60Nb20Ta20) lattice-like preform and AlSi12-matrix was investigated by in-situ compression tests under scanning electron microscopy to get a better understanding of the influence of the lattice-like preform and mechanical interference between both phases. Additionally, microstructure analysis by scanning transmission electron microscopy and energy dispersive X-ray measurements were carried out to gain insight into the chemical composition of the interfaces. The failure behavior in manufacturing direction of the MMC is dominated by shear stress whereas transversely to manufacturing direction by normal stress and exhibits therefore an anisotropic failure behavior. Investigations of the interfaces show more of a mechanical than chemical bonding but in general a good interfacial bonding was confirmed.

金属玻璃(MG)具有非晶态原子结构,表现出多种优异特性,如高强度、与高弹性应变极限相关的硬度和弹性储能。但金属玻璃也容易发生脆性断裂,因此难以用作整体结构组件,最好是用作金属基复合材料(MMC)等混合复合材料的增强相。复合材料的破坏行为取决于增强相的结构。在这项研究中,通过在扫描电子显微镜下进行原位压缩试验,研究了用 MG(Ni60Nb20Ta20)晶格状预成型体和 AlSi12 基质增强的互穿 MMC 的破坏行为,以便更好地了解晶格状预成型体的影响以及两相之间的机械干涉。此外,还通过扫描透射电子显微镜和能量色散 X 射线测量进行了微观结构分析,以深入了解界面的化学成分。MMC 在制造方向上的破坏行为由剪应力主导,而横向破坏行为则由法向应力主导,因此表现出各向异性的破坏行为。对界面的研究表明,机械结合多于化学结合,但总体而言,界面结合良好。


Composites Part A: Applied Science and Manufacturing

Deformation characterization of multi-morphology composite cellular hyperelastic structure under biaxial tension: Analytic approaches for sensor applications

Youngdoo Kim, Seung-Hwan Chang

doi:10.1016/j.compositesa.2024.108167

双轴拉伸下多形态复合蜂窝超弹性结构的变形表征:传感器应用的分析方法

As a preliminary study to develop an effective stretchable sensor, we implemented multi-morphology cellular structures in the gauge area of a biaxial tensile specimen to obtain the desired biaxial mechanical behaviour. A numerical parametric study was conducted by considering the unit cell geometries, four biaxial tension conditions, and three groups of unit cells. The parametric study reveals that a multi-morphology composite cellular (M2C2) specimen with compliant unit cells near the centre and stiff unit cells along the border of the gauge area shows high linearity between the force and displacement relationships and high compliance. M2C2 specimens optimised using the Bayesian optimisation process share similar geometric patterns found in the parametric study and show enhancements in linearity and compliance up to 40.4 % and 65.6 %, respectively, compared with those of a conventional solid specimen.

作为开发有效可拉伸传感器的初步研究,我们在双轴拉伸试样的量规区域采用了多形态单元结构,以获得所需的双轴机械性能。通过考虑单元格几何形状、四种双轴拉伸条件和三组单元格,进行了数值参数研究。参数研究结果表明,在靠近中心的单元格为顺应性单元格,沿着量规区域边界的单元格为刚性单元格的多形态复合单元格(M2C2)试样显示出力与位移关系的高度线性和高顺应性。使用贝叶斯优化过程优化的 M2C2 试样与参数研究中发现的几何形态相似,与传统的实心试样相比,线性度和顺应性分别提高了 40.4% 和 65.6%。


Composites Part B: Engineering

ECM-based ca2+/l-arginine/NO periosteum nourishes bone defect microenvironment, directs macrophage polarity, and accelerates osteogenesis and angiogenesis

Ho-Pan Bei, Xiongfa Ji, Tianpeng Xu, Zhenhua Chen, Chun-Hei Lam, Xintong Zhou, Yuhe Yang, Yu Zhang, Chunyi Wen, Yaxiong Liu, Xin Zhao

doi:10.1016/j.compositesb.2024.111410

基于 ECM 的 ca2+/l- 精氨酸/NO 骨膜可滋养骨缺损微环境,引导巨噬细胞极性,加速骨生成和血管生成

The natural periosteum is responsible for supporting bone homeostasis and initiating repair, but is often damaged during bone fracture, causing acute inflammation and loss of a functioning substratum for induction of new bone formation. Here, we propose an ECM-based Ca2+/l-arginine/nitric oxide (NO) electrospun periosteum to reinitiate bone regeneration. The multifaceted action of NO could promote osteoblastic differentiation, angiogenesis and polarization of macrophages, while accelerating new bone formation, enhancing bone quality and reducing inflammation in a rat critical size calvarial defect model, acting as a mainspring that drives the rest of the PI3K-AKT pathway including the downstream action of VEGF, MAPK and mTOR signalling. The modulation of NO cycle by periosteum scaffold is envisioned to be highly efficient at supporting bone grafting surgeries, with simple and clean clinical translation and implications for anti-inflammatory healing.

天然骨膜负责支持骨平衡和启动修复,但在骨折过程中往往会受到破坏,导致急性炎症,失去诱导新骨形成的功能基质。在这里,我们提出了一种基于 ECM 的 Ca2+/l- 精氨酸/一氧化氮(NO)电纺骨膜来重新启动骨再生。在大鼠临界尺寸腓骨缺损模型中,一氧化氮的多方面作用可促进成骨细胞分化、血管生成和巨噬细胞极化,同时加速新骨形成、提高骨质量并减少炎症,是驱动 PI3K-AKT 通路其余部分(包括 VEGF、MAPK 和 mTOR 信号的下游作用)的主要动力。骨膜支架对氮氧化物循环的调节可高效地支持植骨手术,并可简单明了地应用于临床,对抗炎愈合具有重要意义。


Composites Science and Technology

Achieving super-tough high-density polyethylene with promising foamability using silane crosslinked polyolefin elastomer nanofibrils network

Mohamad Kheradmandkeysomi, Amirmehdi Salehi, Amirjalal Jalali, Hamidreza Akrami, Chul B. Park

doi:10.1016/j.compscitech.2024.110576

 

利用硅烷交联聚烯烃弹性体纳米纤维网络实现具有良好发泡性能的超强韧性高密度聚乙烯

This study presents the in-situ rubber nanofibrillation of high-density polyethylene (HDPE), metallocene based polyolefin elastomer (POE) composites employing spunbond technology. The process commenced with the grafting of vinyl trimethoxy silane (VTMS) onto POE chains, a crucial step to preserve the fibrillar structure. Two distinct peroxide initiators, dicumyl peroxide (DCP) and di(t-butyl) peroxide (DTBP), were employed to initiate the grafting reaction. Results from gel content and melt flow index tests demonstrated that DTBP performed more effectively as an initiator than DCP. The grafted elastomers were then incorporated into the HDPE matrix using spunbonding. Subsequently, the fibrillated POE-g-VTMS were crosslinked using moisture to preserve the morphology. Scanning electron microscopy (SEM) images showed the generation of crosslinked nano-scale size POE-g-VTMS fibers in the range of 50–125 nm. Based on the rheological data, drawn crosslinked POE-g-VTMS phase formed an interconnected network, resulting in a remarkable increase in viscosity and storage modulus at the low-frequency range. Additionally, the stretched samples exhibited noticeable strain-hardening behavior at specific extension rates. Notably, this in-situ fibrillation process significantly enhanced HDPE's foaming ability, evident in decreased cell size and increased cell density. Tensile test results conducted at room temperature and subzero temperature (−40 °C) also suggested a substantial enhancement in the elongation at break of the HDPE nanofibrillated composites compared to the unstretched samples.

本研究采用纺粘技术对高密度聚乙烯(HDPE)和茂金属基聚烯烃弹性体(POE)复合材料进行原位橡胶纳米纤化。该工艺首先将乙烯基三甲氧基硅烷(VTMS)接枝到 POE 链上,这是保持纤维结构的关键步骤。接枝反应采用了两种不同的过氧化物引发剂,即过氧化二辛酯(DCP)和过氧化二(叔丁基)酯(DTBP)。凝胶含量和熔体流动指数测试结果表明,DTBP 作为引发剂比 DCP 更有效。接枝的弹性体随后通过纺粘法与高密度聚乙烯基体结合。随后,利用湿气对纤维化的 POE-g-VTMS 进行交联,以保持其形态。扫描电子显微镜(SEM)图像显示,生成的交联纳米级 POE-g-VTMS 纤维的尺寸范围为 50-125 nm。根据流变学数据,拉伸交联的 POE-g-VTMS 相形成了一个相互连接的网络,导致低频范围内的粘度和存储模量显著增加。此外,拉伸样品在特定拉伸速率下表现出明显的应变硬化行为。值得注意的是,这种原位纤化过程显著增强了高密度聚乙烯的发泡能力,表现为细胞尺寸减小,细胞密度增加。在室温和零下温度(-40 °C)下进行的拉伸测试结果也表明,与未拉伸样品相比,高密度聚乙烯纳米纤化复合材料的断裂伸长率大幅提高。


Novel approach for optimizing mechanical and damping performance of MABS composites reinforced with basalt fibers: An experimental study

Md Abu Shaid Sujon, Davide Masato, Tito Andriollo, Zhihao Pan, Venkata Karthik Nadimpalli, Vicente Cutanda Henriquez, Aminul Islam

doi:10.1016/j.compscitech.2024.110578

 

优化用玄武岩纤维增强的 MABS 复合材料的机械和阻尼性能的新方法:实验研究

The purpose of this research is to explore how basalt fibers, when compounded in specific proportions, impact the mechanical and damping attributes of methyl methacrylate acrylonitrile butadiene styrene (MABS). The fabrication process involved compounding basalt fibers in a twin-screw extruder at four distinct weight percentages: 5%, 10%, 15%, and 20%, with an MABS matrix. This study uniquely employs a comprehensive suite of characterization techniques—including dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), X-ray microcomputed tomography (micro-CT), scanning electron microscopy (SEM), tensile tests, and density measurements—to evaluate the composite's performance. The research significantly reveals that the integration of basalt fibers enhances the damping characteristics of MABS composites, as confirmed by DMA. Additionally, micro-CT scans provide unprecedented insights into the uniform distribution of basalt fibers within the MABS matrix, thereby elucidating the underlying mechanisms for the observed improvements. TGA data further bolsters the composite's thermal resilience, revealing its aptitude for high-temperature applications. Our findings establish a novel correlation between the basalt fiber weight percentage and the damping properties, revealing a non-monotonic relationship. This study thus not only augments the understanding of MABS-based composites but also opens new avenues for the exploitation of basalt fibers in advanced composite materials, particularly in terms of their damping capabilities.

本研究的目的是探讨玄武岩纤维按特定比例混合后,如何影响甲基丙烯酸甲酯丙烯腈丁二烯苯乙烯(MABS)的机械和阻尼属性。制造过程包括在双螺杆挤出机中以四种不同的重量比例混合玄武岩纤维:5%、10%、15% 和 20% 的比例与 MABS 基质混合。这项研究独特地采用了一整套表征技术,包括动态机械分析 (DMA)、热重分析 (TGA)、X 射线微计算机断层扫描 (micro-CT)、扫描电子显微镜 (SEM)、拉伸试验和密度测定,以评估复合材料的性能。研究结果表明,玄武岩纤维的集成增强了 MABS 复合材料的阻尼特性,这一点已得到 DMA 的证实。此外,显微 CT 扫描为了解玄武岩纤维在 MABS 基体中的均匀分布提供了前所未有的视角,从而阐明了所观察到的改进的内在机制。TGA 数据进一步增强了复合材料的热弹性,揭示了其在高温应用中的适用性。我们的研究结果在玄武岩纤维重量百分比和阻尼特性之间建立了一种新的相关性,揭示了一种非单调关系。因此,这项研究不仅加深了人们对基于 MABS 的复合材料的了解,还为在先进复合材料中利用玄武岩纤维开辟了新的途径,尤其是在阻尼能力方面。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemDeformGENESIS断裂复合材料非线性化学电子理论材料储能MEMS试验
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首次发布时间:2024-11-13
最近编辑:9天前
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【新文速递】2024年4月3日复合材料SCI期刊最新文章

今日更新:Composites Part B: Engineering 2 篇Composites Part B: EngineeringEnhanced photocatalytic performance of MXene-Modified cation-exchanged CoFe-LDH/CoFeCrO4 heterostructure for Antibiotic degradation and hydrogen production through synergistic charge dynamicsLekha Paramanik, Lagnamayee Mohapatra, Dong Yun Choi, Seung Hwa Yoodoi:10.1016/j.compositesb.2024.111416通过协同电荷动力学提高 MXene 改性阳离子交换 CoFe-LDH/CoFeCrO4 异质结构在抗生素降解和制氢中的光催化性能Systemizing an effective charge-transfer channel across a junction interface replete with ample active sites for enhancing the photocatalytic activity of semiconducting materials presents a formidable challenge. Here, we present a novel approach based on an in situ hydrothermal method for synthesizing CoFe-Layered Double Hydroxide (LDH)/CoFeCrO4 heterojunction materials that were partially derived from CoFe-LDH. These materials synergistically interact with Ti3C2 MXene nanosheets facilitating multi-interface interactions. Indeed, the highest tetracycline hydrochloride degradation rate of nearly 92% in 2 h was achieved because of the intense synergy between the CoFe-LDH/CoFeCrO4 heterojunction material optimized with 7.5 wt.% of MXene nanosheets (CMC-7.5). This degradation performance was 3.1 times greater than that of the original CoFe-LDH. Further, CMC-7.5 produces the highest H2 gas of 458.79 μmol h−1g−1 from a photocatalytic water splitting reaction. The formation of a Schottky energy barrier between the partially derived CoFe-LDH/CoFeCrO4 unit and MXene promoted the fast transfer of photogenerated electrons from CoFe-LDH/CoFeCrO4 to the surface of MXene, thereby providing a plethora of active sites for photocatalytic reactions. Photoelectrochemical assessments using transient and linear sweep voltammetry along with electrochemical impedance spectroscopy confirmed efficient charge carrier transfer. Moreover, the optimized CMC-7.5 photoelectrode has a superior integral area and exhibited excellent stability over 100 cycles. Finally, the study outlines the construction of several advanced materials with multi-interface heterojunctions involving cation-exchanged LDH derivatives with high photogenerated charge carrier separation efficiency and minimal interfacial migration resistance to serve as stability benchmarks for practical applications.在具有大量活性位点的结界面上建立有效的电荷转移通道,以提高半导体材料的光催化活性,是一项艰巨的挑战。在此,我们提出了一种基于原位水热法的新方法,用于合成 CoFe 层状双氢氧化物(LDH)/CoFeCrO4 异质结材料。这些材料与 Ti3C2 MXene 纳米片协同作用,促进了多界面相互作用。事实上,由于 CoFe-LDH/CoFeCrO4 异质结材料与 7.5 wt.% 的 MXene 纳米片(CMC-7.5)之间的强烈协同作用,盐酸四环素在 2 小时内的降解率最高,接近 92%。这种降解性能是原始 CoFe-LDH 的 3.1 倍。此外,CMC-7.5 在光催化水分离反应中产生的 H2 气体最高,达到 458.79 μmol h-1g-1。在部分衍生的 CoFe-LDH/CoFeCrO4 单元和 MXene 之间形成的肖特基能障促进了光生电子从 CoFe-LDH/CoFeCrO4 向 MXene 表面的快速转移,从而为光催化反应提供了大量的活性位点。使用瞬态和线性扫描伏安法以及电化学阻抗光谱法进行的光电化学评估证实了高效的电荷载流子转移。此外,优化后的 CMC-7.5 光电极具有优异的积分面积,在 100 次循环中表现出卓越的稳定性。最后,该研究概述了几种先进的多界面异质结材料的构造,这些材料涉及阳离子交换 LDH 衍生物,具有较高的光生电荷载流子分离效率和最小的界面迁移阻力,可作为实际应用的稳定性基准。Dynamic and seismic response characteristics of above-ground flax fiber-reinforced epoxy pipesSaeed Eyvazinejad Firouzsalari, Dmytro Dizhur, Krishnan Jayaraman, Jason Inghamdoi:10.1016/j.compositesb.2024.111426地面亚麻纤维增强环氧树脂管道的动态和地震响应特性Dynamic and seismic response characteristics of free-spanning flax fibre-reinforced epoxy (FFRE) pipes with various diameters of 38, 60, 100, 160, and 205 mm and different fabric layers of 2, 3, and 4 (thickness of 3.4 mm–6.65 mm), and a free span of 3870 mm were investigated experimentally and numerically. The FFRE pipes were subjected to harmonic ground motions with peak ground acceleration of 0.1g, 0.2g, and 0.3g, vibration frequency of 2, 3, and 4 HZ, and a duration of 40 s, and a record from the 2011 Christchurch earthquake when the pipe was empty, half-filled or completely-filled with water to establish the effect of peak ground acceleration, vibration frequency, pipe water content, diameter and thickness on pipe displacement, acceleration, strains, and internal pressure. FFRE pipes underwent larger displacements and strains and higher transverse accelerations when the pipe was completely-filled, while the pipe underwent higher vertical acceleration and higher internal pressure when the pipe was half-filled. The pipe strain increased by up to 719% by increasing the peak ground acceleration from 0.1g to 0.3g, up to 452% by increasing the vibration frequency from 2 to 4 Hz, and up to 1358% by increasing the pipe water content from empty to completely-filled. FFRE pipes remained below their material ultimate limits, and no service or structural failure in the form of seepage or excessive deformation was detected in the pipe body, indicating great potential for using FFRE pipes as an alternative option to conventional pipes at seismic zones.实验和数值研究了自由跨度为 38、60、100、160 和 205 mm,织物层数为 2、3 和 4(厚度为 3.4 mm-6.65 mm),自由跨度为 3870 mm 的亚麻纤维增强环氧树脂(FFRE)管道的动态和地震响应特性。FFRE 管道承受了峰值地面加速度为 0.1g、0.2g 和 0.3g,振动频率为 2、3 和 4 HZ,持续时间为 40 秒的谐波地面运动,以及 2011 年基 督城地震中管道空载、半载或全载注水时的记录,以确定峰值地面加速度、振动频率、管道含水量、直径和厚度对管道位移、加速度、应变和内压的影响。当管道完全充满水时,FFRE 管道的位移和应变更大,横向加速度更高;而当管道半充满水时,管道的垂直加速度更高,内压更高。将地面加速度峰值从 0.1g 提高到 0.3g,管道应变最多可增加 719%;将振动频率从 2 Hz 提高到 4 Hz,管道应变最多可增加 452%;将管道含水量从空增加到完全充满,管道应变最多可增加 1358%。FFRE 管道的强度仍低于其材料极限,并且未发现管体出现渗水或过度变形等使用或结构故障,这表明在地震带使用 FFRE 管道作为传统管道的替代选择具有巨大潜力。来源:复合材料力学仿真Composites FEM

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