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【新文速递】2024年5月6日固体力学SCI期刊最新文章

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今日更新:Mechanics of Materials 1 篇,Thin-Walled Structures 1 篇

Mechanics of Materials

Concurrent delamination propagation and deformation localization in semiconductor devices

Shawn R. Lavoie, Guodong Nian, Chen-Wei Li, Jason Lan, Yu-Sheng Lin, Yi-Lun Lin, Sherwin Tang, Jyun-Lin Wu, Joost J. Vlassak, Zhigang Suo

doi:10.1016/j.mechmat.2024.105027

半导体器件中并发分层传播和变形局部化

In semiconductor devices, metals and polymers are often integrated as electrical conductors and insulators. Fabrication and operation of the devices cause stress in such an integrated structure. The stress can delaminate the metals and polymers, as well as deform them plastically. Here we show that the delamination can localize the deformation in the metals, which form necks to rupture the metals and sever electrical conduction. We simulate the coevolution of delamination propagation and deformation localization. The metals and polymers are modeled as elastic-plastic materials, and their adhesion is represented by a cohesive zone model. The simulation highlights that extensive delamination is a prerequisite for the metals to form necks, and that necking causes delamination to propagate further. Also highlighted are the impact of corners in the structure. Preexisting defects make the structure particularly vulnerable to concurrent delamination and necking. It is hoped that this study will draw renewed attention to the mechanical behavior of materials in the development of the semiconductor industry.

在半导体器件中,金属和聚合物通常作为电导体和绝缘体集成在一起。设备的制造和操作会在这样一个集成结构中产生应力。这种应力会使金属和聚合物分层,并使它们发生塑性变形。研究表明,脱层可以使金属局部变形,形成颈状,使金属断裂,切断导电。模拟了分层扩展和变形局部化的共同演化过程。金属和聚合物被建模为弹塑性材料,它们的粘附用一个内聚区模型来表示。模拟结果表明,广泛的脱层是金属形成颈状的先决条件,而颈状会导致脱层进一步扩散。同样突出的是拐角在结构中的影响。预先存在的缺陷使结构特别容易同时发生分层和颈缩。希望本研究能在半导体工业的发展中引起人们对材料力学行为的重新关注。


Thin-Walled Structures

The adaptive hygrothermo-magneto-electro-elastic coupling improved enriched finite element method for functionally graded magneto-electro-elastic structures

Jiye Wang, Liming Zhou, Yingbin Chai

doi:10.1016/j.tws.2024.111970

自适应湿热-磁-电弹性耦合改进了功能梯度磁-电弹性结构的富集有限元法

In this study, the hygrothermo-magneto-electro-elastic coupling improved enriched finite element method (HC-IEFEM) is proposed to analyze functionally graded magneto-electro-elastic (FG-MEE) structures. The static behavior of FG-MEE structures in the hygrothermal environment is studied. In the enriched finite element method (EFEM) enhanced by interpolation cover functions, the improved shape functions are added to solve the rank defect problem. Quadrilateral elements are used in the analysis of FG-MEE structures in this study. This improved method has proven to be relatively more efficient and resistant to mesh distortion than the traditional finite element method (FEM). Besides, the adaptive mesh refinement (AMR) scheme is used to refine the mesh in local areas to improve numerical calculation efficiency. Numerical examples show that the adaptive HC-IEFEM can achieve relatively high accuracy for analyzing FG-MEE structures. The proposed HC-IEFEM can obtain high accuracy in the hygrothermal environment using a relatively coarse mesh through the improved shape function and AMR scheme. Therefore, the significant potential is demonstrated in analyzing FG-MEE structures in the hygrothermal environment using the proposed adaptive HC-IEFEM.

在本研究中,提出了湿热-磁-电弹性耦合改进富集有限元法(HC-IEFEM)来分析功能梯度磁-电弹性(FG-MEE)结构。研究了FG-MEE结构在湿热环境下的静力性能。在插值覆盖函数增强的丰富有限元法中,加入改进的形状函数来解决秩缺陷问题。在本研究中,四边形单元用于FG-MEE结构的分析。与传统的有限元法相比,这种改进的方法具有更高的效率和抗网格变形能力。此外,采用自适应网格细化(AMR)方案对局部网格进行细化,提高数值计算效率。数值算例表明,自适应HC-IEFEM分析FG-MEE结构具有较高的精度。本文提出的HC-IEFEM通过改进的形状函数和AMR方案,可以在相对粗糙的网格条件下获得较高的湿热环境精度。因此,使用所提出的自适应HC-IEFEM分析湿热环境下的FG-MEE结构显示出巨大的潜力。


来源:复合材料力学仿真Composites FEM
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首次发布时间:2024-11-14
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【新文速递】2024年5月8日复合材料SCI期刊最新文章

今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 3 篇,Composites Science and Technology 5 篇Composite StructuresThe effect of span length on the flexural properties of glass and basalt fiber reinforced sandwich structures with balsa wood core for sustainable shipbuildingMohamed Chairi, Jalal El Bahaoui, Issam Hanafi, Federica Favaloro, Chiara Borsellino, Fabia Galantini, Guido Di Belladoi:10.1016/j.compstruct.2024.118187跨长对可持续造船用玻璃玄武岩纤维增强轻木芯夹层结构抗弯性能的影响The current research aims to analyze the mechanical characterization of sandwich materials through a three-point flexural test. The sandwich structures in question composed of balsa wood as a core and four different types of fiber reinforced vinyl ester composite facesheets, namely Glass, Basalt, Glass/Carbon, and Basalt/Carbon. The sandwich panels were prepared using the vacuum infused processing method. The primary objective of this investigation is to explore the feasibility of utilizing basalt fibers for the production of structural parts in shipbuilding and replacing the already existed glass fibers. The flexural test was carried out with using three-point flexural test with varying the span length from 120 mm, 180 mm, 220 mm. Additionally, an analysis of variance (ANOVA) was then carried out to compare the mean values of properties deduced from these tests. The results showed that using basalt fibers instead of glass fiber reinforced enhanced the flexural stiffness of the sandwich structure. The flexural strength and modulus are shown to depend on span length and fiber type. The flexural modulus increases with an increase in span length. Similarly, flexural strength increases in glass fiber-based structures, while a slight reduction is observed in basalt fiber-reinforced structures the larger span length. The findings of this research suggest that basalt fibers hold potential as a replacement for glass fibers in producing structural components in shipbuilding. These results offer valuable information that can aid in the design and optimization of sandwich materials in shipbuilding.本研究旨在通过三点弯曲试验分析夹层材料的力学特性。该夹层结构由轻木为核心和四种不同类型的纤维增强乙烯酯复合材料面板组成,即玻璃、玄武岩、玻璃/碳和玄武岩/碳。采用真空灌注法制备夹层板。本研究的主要目的是探索利用玄武岩纤维生产造船结构件的可行性,并取代现有的玻璃纤维。采用跨度为120 mm、180 mm、220 mm的三点弯曲试验进行弯曲试验。此外,方差分析(ANOVA),然后进行比较从这些测试推断的属性的平均值。结果表明,用玄武岩纤维代替玻璃纤维增强夹层结构可以提高夹层结构的抗弯刚度。抗弯强度和模量取决于跨度长度和纤维类型。挠曲模量随跨长的增加而增加。同样,玻璃纤维结构的抗弯强度增加,而玄武岩纤维增强结构的抗弯强度在跨度较大时略有降低。该研究结果表明,玄武岩纤维在造船结构部件生产中具有替代玻璃纤维的潜力。这些结果为船舶夹层材料的设计和优化提供了有价值的信息。Energy absorption behavior of aramid/DCPD backing to determining the blunt trauma criterion of a human head in a ballistic helmetKayode Olaleye, Dariusz Pyka, Adam Kurzawa, Mirosław Bocian, Krzysztof Jamroziakdoi:10.1016/j.compstruct.2024.118172芳纶/DCPD的能量吸收行为为确定防弹头盔中人头部钝性损伤标准提供依据The research involved analyzing a material solution for a 9 mm Full Metal Jacket (FMJ) Parabellum loaded with ballistic impact on a resin laminate strengthened with extra aramid layers. The goal of this research is to determine the impact of material (aramid/DCPD) layer thickness on the energy absorption performance of the laminate for blunt trauma as blunt criterion (BC). For this purpose, aramid fiber laminate with dicyclopentadiene (DCPD) resin matrix was prepared. Laminate samples were tested on the drop test and were subjected to ballistic loads. The ABAQUS/Explicit program and finite element method were used to conduct the study. Individual material systems' optimal solutions were created using numerical analysis, and they were then classified using the mass-efficiency criterion. The numerical results were compared with the experimental using samples prepared according to the modeling methods. Selected results were shown and discussed in the later part of the paper.该研究涉及分析9 mm全金属护套(FMJ) Parabellum的材料解决方案,该护套承载弹道冲击,并通过额外的芳纶层加强树脂层压板。本研究的目的是确定材料(芳纶/DCPD)层厚对钝性损伤层压板吸能性能的影响作为钝性标准(BC)。为此,制备了以二环戊二烯(DCPD)树脂为基体的芳纶纤维层压板。层压板试样进行了跌落试验和弹道载荷试验。采用ABAQUS/Explicit程序和有限元法进行研究。使用数值分析创建了单个材料系统的最优解,然后使用质量效率准则对它们进行分类。利用模拟方法制备的试样,将数值计算结果与实验结果进行了比较。选取的结果在论文的后半部分进行了展示和讨论。Uncertain stochastic vibration characteristic analysis of composite laminated rectangular plate based on improved kriging modelYugeng Chen, Rui Zhong, Qingshan Wang, Liming Chen, Bin Qindoi:10.1016/j.compstruct.2024.118180基于改进kriging模型的复合材料叠合矩形板不确定随机振动特性分析The stochastic vibration analysis of composite laminated structures has been conducted extensively in the field of structural dynamics. Existing studies in this field are primarily conducted based on deterministic structural parameters, whereas the effects of parametric uncertainties on the stochastic vibration characteristics of composite laminated structures are disregarded. This study investigates a composite laminated rectangular plate by considering the effect of interval uncertainty in the intrinsic parameters and load on its stochastic vibration characteristics. A rapid analysis model for the structural stochastic vibration characteristics is established based on an improved kriging model. Additionally, an innovative approach that combines the improved kriging model with intelligent optimization is proposed to solve problems pertaining to uncertainty-propagation analysis of structures. Based on this method, an uncertainty-propagation analysis of structural stochastic vibration responses is efficiently implemented. The effectiveness of the proposed method is demonstrated by comparing the results with those obtained from Monte Carlo simulation. The numerical results indicate that different uncertain factors exert varying degrees of effect on the stochastic vibration characteristics of the plate. Finally, the effects of density, elastic modulus ratio, fiber orientation and load on the interval fluctuation patterns of uncertain responses are discussed.复合材料层合结构的随机振动分析在结构动力学领域得到了广泛的研究。该领域的现有研究主要基于确定性结构参数,忽略了参数不确定性对复合材料层合结构随机振动特性的影响。考虑了复合材料层合矩形板固有参数和载荷的区间不确定性对其随机振动特性的影响。基于改进的kriging模型,建立了结构随机振动特性的快速分析模型。此外,提出了一种将改进的克里格模型与智能优化相结合的创新方法来解决结构的不确定性传播分析问题。基于该方法,可以有效地实现结构随机振动响应的不确定性传播分析。通过与蒙特卡罗仿真结果的比较,验证了该方法的有效性。数值结果表明,不同的不确定因素对板的随机振动特性有不同程度的影响。最后讨论了密度、弹性模量比、纤维取向和载荷对不确定响应区间波动模式的影响。Quasi-static and dynamic behavior analysis of 3D CFRP woven laminated composite auxetic structures for load-bearing and energy absorption applicationsEhsan Etemadi, Minglonghai Zhang, Mohaddeseh Gholikord, Keda Li, Mabel Mei Po Ho, Hong Hudoi:10.1016/j.compstruct.2024.118182三维CFRP编织层合复合材料减振结构的准静动态性能分析This paper investigated the quasi-static and dynamic behavior of 3D auxetic metamaterial structures made from carbon fiber reinforced polymer (CFRP) laminated composite. The aim of the study was to enhance design methodologies for load-bearing and energy absorption applications of these 3D novel structures, filling the research gap in understanding their response to quasi-static and especially dynamic loadings. The two novel 3D structures were designed and fabricated by using an interlocking assembly method based on the 2D auxetic CFRP sheets, which were formed with hybrid double-arrow-head with re-entrant and star unit-cells and made with plain weave carbon epoxy prepregs. The finite element (FE) method was adopted to analyze the mechanical characteristics of the structures under the quasi-static and dynamic loading, and Hashin failure criteria were used to define damage in the structures. The study showed that the designed 3D auxetic CFRP structures simultaneously exhibit superior auxeticity, load-bearing, and energy absorption capacity.研究了碳纤维增强聚合物(CFRP)层合复合材料三维增塑型超材料结构的准静态和动态行为。该研究的目的是增强这些3D新型结构的承载和能量吸收应用的设计方法,填补在理解其对准静态,特别是动态负载的响应方面的研究空白。基于复合碳纤维增强玻璃钢(CFRP)复合材料,采用复合双箭头和星形单元格,并采用平纹环氧预浸料制成复合碳纤维增强玻璃钢复合材料,采用联锁装配的方法设计和制造了两种新型三维结构。采用有限元法分析了结构在准静、动载荷作用下的力学特性,并采用Hashin破坏准则定义了结构的损伤。研究表明,所设计的三维碳纤维增强塑料结构同时具有较好的增强性、承载能力和吸能能力。Composites Part A: Applied Science and ManufacturingHigh-temperature transient-induced thermomechanical damage of fiber-reinforced ceramic-matrix composites in supersonic wind tunnelJiangtao Wang, Zhengmao Yang, Rui Yang, Jian Jiao, Lianjie Yue, Xiao Houdoi:10.1016/j.compositesa.2024.108243超声速风洞中纤维增强陶瓷基复合材料高温瞬态热力学损伤研究This article is based on the supersonic directly connected wind tunnel. Through a specially designed experimental chamber, combined with infrared temperature measurement, high-speed camera, etc., in-situ monitoring of composite materials under airflow at Ma 3.0 with a total temperature of 950 ∼ 1473K was carried out. The dimensional analysis method was used to propose dimensionless parameters to characterize the thermal coupling caused by high-speed airflow thermal shock. Research has shown that the thermal coupling effect of supersonic airflow causes uneven temperature inside the material, and the thermal stress caused by temperature gradient changes (including increasing and decreasing processes) is the main reason for material damage. The damage of ceramic matrix composites under thermal shock mainly manifests as a decrease in surface roughness, surface fiber fracture and a decrease in elastic modulus. In addition, the study also found that there are damage thresholds for the thermal shock effect of airflow at different total temperatures, which helps to further understand the thermomechanical damage mechanism and degradation law of composite structure under high-temperature transient conditions.本文基于超音速直连风洞。通过专门设计的实验舱,结合红外测温、高速摄像等手段,对复合材料在 Ma 3.0 气流下的总温度 950 ∼ 1473K 进行了原位监测。利用尺寸分析方法提出了表征高速气流热冲击引起的热耦合的无量纲参数。研究表明,超音速气流的热耦合效应导致材料内部温度不均匀,温度梯度变化(包括上升和下降过程)引起的热应力是材料损伤的主要原因。陶瓷基复合材料在热冲击下的损伤主要表现为表面粗糙度下降、表面纤维断裂和弹性模量降低。此外,研究还发现不同总温下气流热冲击效应存在损伤阈值,有助于进一步了解高温瞬态条件下复合材料结构的热力学损伤机理和降解规律。Compression and hydrothermal ageing after impact of carbon fibre reinforced epoxy laminatesRowan L. Caldwell, Peter Davies, Mael Arhant, B. Gangadhara Prustydoi:10.1016/j.compositesa.2024.108258 碳纤维增强环氧层压板冲击后的压缩和水热老化This paper proposes a new methodology for the assessment of seawater ageing effects on impact-damaged composite laminates. CF/Epoxy laminates which were unimpacted, and impacted at 30 J, 60 J, and 90 J by hemispherical and conical impactors were subject to 4 months hydrothermal ageing in renewed natural seawater at 60 +/-2 °C. The majority of water uptake by impacted laminates (0.05 wt% − 0.3 wt%) occurred in the first 24 h and is believed to be held in damage cavities by capillary mechanisms. The increase in diffusive water uptake rate by the matrix due to impact damage was only small, at less than 0.008 wt%.mm.hr−0,5, compared with the total diffusive water uptake rate of 0.1 wt%.mm.hr−0,5. Hydrothermal ageing reduced the residual compressive strength of pristine laminates by 25 % and impact-damaged laminates by 8 % to 16 % for impacts between 30 J and 90 J.提出了一种评估海水老化对冲击损伤复合材料层合板影响的新方法。未受冲击以及在30 J、60 J和90 J下受半球形和锥形冲击的CF/环氧树脂层合板在60 +/-2 °C的再生自然海水中进行了4 个月的热液老化。受冲击层压板的大部分吸水(0.05 wt% - 0.3 wt%)发生在前24 小时,并且被认为是通过毛细管机制保持在损伤腔中。冲击损伤导致基体扩散吸水率的增加很小,小于0.008 wt%.mm。总扩散吸水率为0.1 wt%.mm. Hr−0,5。在30 J和90 J之间,水热老化使原始层压板的残余抗压强度降低了25% %,冲击损伤层压板的残余抗压强度降低了8% %至16% %。Composites Part B: EngineeringBiomimetic papilla texture by femtosecond laser for high-strength CFRTP/A6061-T6 FSSW hybrid structuresXiaoyang Bi, Hua Liu, Yan Li, Mengjia Xu, Zhenmin Wangdoi:10.1016/j.compositesb.2024.111500飞秒激光对高强度CFRTP/A6061-T6 FSSW杂化结构的仿生乳 头织构The lightweight design concept in structural applications has generated interest in hybrid structures of carbon-fiber-reinforced thermoplastics (CFRTP) and metals as attractive structure components. However, these hybrid structures face challenges due to the significant differences in physical and chemical properties between CFRTP and metals, resulting in limited strength and rendering them unsuitable for advanced transportation. To address these limitations, the current research focuses on creating a biomimetic texture on A6061-T6 (6061) surfaces using femtosecond laser to manufacture high-strength hybrid structures, inspired by organismal body surfaces. The CFRTP and 6061 were joined by friction stir spot welding (FSSW). The femtosecond laser treatment produces double-scale roughness on 6061 surfaces and causes carbon to absorb into alumina. These changes in physical and chemical structures enhance the compatibility between 6061 and CFRTP. The biomimetic rough aluminum surface creates effective mechanical interlock at the interface with CFRTP, preventing the initiation and propagation of fracture cracks. The presence of absorbed carbon enhances the Al-O covalency, which influences the bonding behavior at CFRTP/6061 interfaces. The improved compatibility, mechanical interlock, and enhanced bonding behavior synergistically strengthen the joint strength of CFRTP/6061 hybrid structure modified by the biomimetic papilla structure. Current biomimetic design strategy inherits the remarkable natural wisdom and is expected to provide valuable insights for the development and application of CFRTP/metal hybrid structures.结构应用中的轻量化设计概念引起了人们对碳纤维增强热塑性塑料(CFRTP)和金属混合结构作为有吸引力的结构部件的兴趣。然而,由于CFRTP与金属在物理和化学性质上的显著差异,这些混合结构面临着挑战,导致其强度有限,不适合先进的运输。为了解决这些限制,目前的研究重点是利用飞秒激光在A6061-T6(6061)表面上创建仿生纹理,以制造高强度混合结构,灵感来自生物体表面。采用搅拌摩擦点焊(FSSW)连接CFRTP和6061。飞秒激光处理在6061表面产生双尺度粗糙度,并导致碳被氧化铝吸收。这些物理和化学结构的变化增强了6061与CFRTP的相容性。仿生粗糙铝表面与CFRTP界面形成有效的机械联锁,防止断裂裂纹的萌生和扩展。吸附碳的存在增强了Al-O共价,影响了CFRTP/6061界面的成键行为。仿生乳 头结构修饰的CFRTP/6061杂化结构的相容性改善、机械互锁、键合行为增强,协同增强了其结合强度。目前的仿生设计策略继承了非凡的自然智慧,有望为CFRTP/金属混合结构的发展和应用提供有价值的见解。From experimental testing to computational modelling: A review of shape memory alloy fiber-reinforced concrete compositesAlireza Tabrizikahou, Mieczysław Kuczma, Christoph Czaderski, Moslem Shahverdidoi:10.1016/j.compositesb.2024.111530从实验测试到计算模型:形状记忆合金纤维增强混凝土复合材料综述Shape memory alloys (SMAs) have unique characteristics, such as the shape memory effect, which allows them to recover their initial shape after being deformed when stimulated, and pseudoelasticity, which enables them to accommodate large deformation without residual strains after being unloaded. SMAs may be used as short fibers in fiber-reinforced concrete (FRC) composites to pre-stress, heal fractures, and re-center themselves. As a result, SMA-FRC is a potential alternative to conventional construction materials in a wide range of applications. SMA-FRC composite application and modeling may present challenges, such as computational modeling complexities, practical constraints regarding fiber volume fraction, fiber-to-concrete adhesion strength, and the complex temperature-based activation of SMA fibers embedded in concrete. Despite these challenges and difficulties, significant work toward resolution is being made, making SMA-FRC an innovative technology with many potential research and development alternatives. This article presents an overview of experimental testing, computational methods, limitations, and future research potential for SMA-FRC composite materials. The study also looks at practical applications of SMA fibers in concrete composites including beam–column junctions, pre-stressing, and self-healing, as well as major developments and implications. The advantages and limits of several computational strategies for studying SMA-FRCs are discussed. The research suggests multiscale modeling as an effective approach for analyzing SMA-FRC, and a unique example of SMA-FRC multiscale modeling is briefly demonstrated. In conclusion, this research emphasizes the significant potential of SMA-FRC composites as novel construction materials with prospective practical applications, as well as the importance of multiscale modeling in SMA-FRC computational modeling.形状记忆合金(sma)具有独特的特性,如形状记忆效应,使其在受刺 激变形后能够恢复其初始形状,以及伪弹性,使其能够在卸载后适应大变形而不产生残余应变。sma可以用作纤维增强混凝土(FRC)复合材料中的短纤维,用于预应力、愈合裂缝和重新居中。因此,SMA-FRC在广泛的应用中是传统建筑材料的潜在替代品。SMA- frc复合材料的应用和建模可能会带来挑战,例如计算建模的复杂性、纤维体积分数、纤维与混凝土粘合强度的实际限制,以及嵌入混凝土中的SMA纤维基于温度的复杂活化。尽管存在这些挑战和困难,但人们正在努力解决这些问题,使SMA-FRC成为一项具有许多潜在研究和开发替代方案的创新技术。本文概述了SMA-FRC复合材料的实验测试、计算方法、局限性和未来的研究潜力。该研究还着眼于SMA纤维在混凝土复合材料中的实际应用,包括梁柱连接、预应力和自修复,以及主要发展和影响。讨论了几种用于研究SMA-FRCs的计算策略的优点和局限性。研究表明,多尺度建模是分析SMA-FRC的有效方法,并简要介绍了一个独特的SMA-FRC多尺度建模实例。总之,本研究强调了SMA-FRC复合材料作为具有实际应用前景的新型建筑材料的巨大潜力,以及SMA-FRC计算建模中多尺度建模的重要性。Coating effect of metal organic complex (Co-DTPMP) layer on enhancing PEC water oxidation performance of BiVO4 photoanodeAlaa Magdy Saad, Mostafa Saad Sayed, Amr Hussien Mady, Woo Kyoung Kimdoi:10.1016/j.compositesb.2024.111534 金属有机配合物(Co-DTPMP)涂层对提高BiVO4光阳极PEC水氧化性能的影响Photoelectrochemical (PEC) water splitting is a promising method for transforming solar energy into clean and sustainable energy. However, PEC is severely limited, and they cannot achieve the predicted photocurrent density owing to the severe photochemical deterioration of the electrode and the recombination of photogenerated carriers. In this study, BiVO4/Co- diethylenetriamine Penta (methylene phosphonic acid) (BVO/Co-DTPMP) co-catalyst was successfully prepared as a nanoporous photoanode. Diethylenetriamine Penta (methylene phosphonic acid) was crosslinked with Co ions and coated on the BiVO4 surface by successive ionic layer adsorption and reaction (SILAR) to reduce fast recombination, which correlated with the BiVO4 photoanode. Various characterization and PEC measurements were conducted, revealing that the co-catalyst thin layer enhanced the charge separation and electrons transfer which significantly affected on the PEC performance of BiVO4, and the current density by BVO/Co-DTPMP was 4 mA cm−2 at 1.23 V vs. RHE. Furthermore, the co-catalyst exhibited improved charge transport and long-term stability.光电化学水分解是一种很有前途的将太阳能转化为清洁和可持续能源的方法。然而,PEC受到严重限制,由于电极严重的光化学劣化和光生载流子的重组,它们无法达到预期的光电流密度。本研究成功制备了BiVO4/Co-二乙烯三胺五亚甲基膦酸(BVO/Co- dtpmp)共催化剂作为纳米孔光阳极。二乙烯三胺五(亚甲基膦酸)与Co离子交联,并通过连续离子层吸附和反应(SILAR)涂覆在BiVO4表面,以减少快速复合,这与BiVO4光阳极相关。各种表征和PEC测量结果表明,共催化剂薄层增强了BiVO4的电荷分离和电子转移,显著影响了BiVO4的PEC性能,BVO/Co-DTPMP在1.23 V时的电流密度为4 mA cm−2。此外,共催化剂表现出更好的电荷输运和长期稳定性。Composites Science and TechnologyComparison of piezoresistive sensitivity based on the size of silica as secondary filler on hybrid CNT compositesKun-Woo Nam, Oh-Nyoung Hur, Byung-Ho Kang, Sung-Hoon Parkdoi:10.1016/j.compscitech.2024.110642 杂化碳纳米管复合材料中二次填料二氧化硅尺寸对压阻灵敏度的影响Recent research has increasingly focused on the potential applications of carbon nanotube (CNT) hybrid composites in wearable sensor technologies. Piezoresistivity, which is characterized by the ability to detect alterations in electrical resistance in response to external forces, is a pivotal attribute of resistive sensors. Numerous studies have attempted to improve this performance by incorporating secondary fillers. Despite extensive efforts to comprehend the influence of the dimensions of secondary fillers on electrical conductivity under static and dynamic conditions, notable confusion persists in the literature regarding the comparative analysis of the effects of nano- and microscale secondary fillers. In this study, two distinct sizes of silica particles were introduced as secondary fillers in CNT/polymer composites, followed by a rigorous comparative analysis of their mechanical and electrical properties under static conditions. Furthermore, this study assessed the influence of the silica particle size on the electrical resistance under dynamic tensile conditions, elucidating its impact on the conductive network.碳纳米管(CNT)复合材料在可穿戴传感器技术中的潜在应用日益受到关注。压阻性是电阻式传感器的关键属性,其特点是能够检测响应外力的电阻变化。许多研究都试图通过加入二次填料来改善这一性能。尽管在理解静态和动态条件下二次填料的尺寸对电导率的影响方面做了大量的努力,但关于纳米级和微米级二次填料影响的比较分析,文献中仍然存在明显的混乱。在这项研究中,引入了两种不同尺寸的二氧化硅颗粒作为CNT/聚合物复合材料的二次填料,然后对它们在静态条件下的力学和电学性能进行了严格的比较分析。此外,本研究还评估了动态拉伸条件下二氧化硅粒径对电阻的影响,阐明了其对导电网络的影响。Microstructural Evolution of Highly Aligned Discontinuous Fiber Composites during Longitudinal Extension in FormingThomas A. Cender, Pavel Simacek, John W. Gillespie, Suresh G. Advanidoi:10.1016/j.compscitech.2024.110649 高对准不连续纤维复合材料纵向拉伸成形过程中的显微组织演变The longitudinal extensional viscosity of a highly aligned discontinuous fiber (ADF) thermoplastic matrix composite is investigated to develop a model and validate microstructural evolutionary mechanisms. Samples stretched at constant temperature and strain rate are shown to exhibit a strain softening behavior. X-ray CT analysis and optical micrographs show that the composite microstructure deconsolidates before forming and evolves with deformation. The conventional unit cell micromechanical model includes the effects of matrix viscosity, fiber aspect ratio and fiber volume fraction. This model is modified to include the stiffening effect of fiber spacing variability, and the softening effects of porosity and decreasing fiber overlap length with elongation. Calibration of the model reveals that matrix shear strain rate is an order of magnitude higher than previously predicted due to local fiber spacing. This effect is captured by a fiber spacing variability parameter which scales average spacing down by an order of magnitude. The observed strain softening behavior is described and a combinations of fiber overlap length reduction and local fiber spacing increase.研究了高度排列不连续纤维(ADF)热塑性基复合材料的纵向拉伸粘度,建立了模型并验证了微观结构的演化机制。在恒定温度和应变速率下拉伸的样品显示出应变软化行为。x射线CT分析和光学显微照片表明,复合材料的微观组织在成形前就开始反固结,并随着变形而演变。传统的单胞细观力学模型考虑了基体粘度、纤维长径比和纤维体积分数的影响。对该模型进行了修正,加入了纤维间距变异性的增强效应、孔隙率和纤维重叠长度随伸长率的减小而减小的软化效应。模型的校正表明,由于局部纤维间距的影响,基体剪切应变率比先前预测的高一个数量级。这种效应由光纤间距变异性参数捕获,该参数将平均间距缩小一个数量级。描述了观察到的应变软化行为和纤维重叠长度减少和局部纤维间距增加的组合。Biobased, recyclable, and multi-functional high-performance composites for electromagnetic interference shieldingXiao-Li Zhao, Yi-Dong Li, Long-Yang Zhan, Jian-Bing Zengdoi:10.1016/j.compscitech.2024.110635 生物基,可回收,多功能高性能电磁干扰屏蔽复合材料High-performance fiber-reinforced thermoset composites (FRTCs) are highly demanded in modern society but are challenged because they depend on nonrenewable fossil-based feedstocks, are hard to recycle after service, and lack advanced functions. Here, we report a methodology to fabricate sustainable, recyclable, high-performance, and multifunctional FRTCs from renewable feedstocks such as vanillin, glycerol triglycidyl ether, 1,10-diaminodecane, and basalt fiber. We designed a mussel-inspired approach to prepare high conductive basalt fiber (CBF), and combined the CBF with a fully biobased covalent adaptable network (CAN) based on dynamic imine bonds to produce the composites i.e., CAN/CBF laminar composites through a solvent-free method. The CAN/CBF composites showed highly reinforced mechanical properties and multiple functionalities including electromagnetic interference shielding, shape memory and self-adhesion characters through combination in the advantages and functions of both CAN and CBF. Furthermore, we demonstrate that the CAN matrix and the reinforced CBF can be recycled separately and can be further reformed to the CAN/CBF composites due to the dynamic nature of the CAN matrix. Our study thus provides an urgently applicable approach for advanced manufacturing toward the green and circular advanced composites economy.高性能纤维增强热固性复合材料(frtc)在现代社会需求量很大,但由于其依赖于不可再生的化石基原料,使用后难以回收,缺乏先进的功能而受到挑战。在这里,我们报告了一种利用可再生原料(如香兰素、甘油三甘油酯醚、1,10-二氨基癸烷和玄武岩纤维)制造可持续、可回收、高性能和多功能frtc的方法。我们设计了一种以贻贝为灵感的方法来制备高导电性玄武岩纤维(CBF),并将CBF与基于动态亚胺键的全生物基共价自适应网络(CAN)结合,通过无溶剂方法制备了CAN/CBF层状复合材料。通过将CAN和CBF的优点和功能结合在一起,CAN/CBF复合材料具有高强度的力学性能和电磁干扰屏蔽、形状记忆和自粘等多种功能。此外,我们证明了CAN基体和增强的CBF可以单独回收,并且由于CAN基体的动态特性,可以进一步改造成CAN/CBF复合材料。因此,我们的研究为实现绿色循环先进复合材料经济的先进制造提供了一条迫切适用的途径。Low velocity impact response of Automated Fiber Placement Advanced Placed Ply compositesRutger Kok, Ramón Cuvillo, Verónica Rodríguez-García, Jesús Pernas, José Alfonso Artero-Guerrero, Roberto Guzmán de Villoria, Francisca Martínez-Herguetadoi:10.1016/j.compscitech.2024.110636 自动铺放先进铺层复合材料的低速冲击响应This study explores the influence of the internal architecture in the low-velocity impact response of Automated Fiber Placement Advanced Placed Ply laminates. AP-PLY laminates with different lay-up are subjected to low velocity impact and compression after impact experiments. Different performance in terms of damage tolerance is obtained as a function of their internal architecture. Triaxial and quasi-isotropic AP-PLY configurations presented a reduced extension of the delamination in comparison to cross-ply panels. As a result, the cross-ply configuration exhibited a drastic loss in residual strength of 49.1% when subjected to 50 J of impact energy. Numerical simulations were employed to provide insight into the deformation and failure mechanisms (e.g., matrix cracking of directly impacted yarns, delamination or tow debonding), and assess the performance of AP-PLY against conventional angle-ply laminates, predicting larger delamination for the latter, showing the potential of the AP-PLY architecture to produce laminates with improved low-velocity impact performance.本研究探讨了内部结构对自动铺放先进铺层板低速冲击响应的影响。通过冲击试验,对不同铺层的AP-PLY复合材料进行了低速冲击和压缩试验。在损伤容限方面的不同性能是其内部结构的函数。与交叉铺层板相比,三轴和准各向同性AP-PLY配置的分层扩展减少。结果表明,当冲击能量为50j时,交叉层结构的残余强度损失高达49.1%。通过数值模拟,研究了AP-PLY复合材料的变形和破坏机制(例如,直接撞击纱线的基体开裂、分层或束脱粘),并评估了AP-PLY复合材料与传统角股复合材料的性能,预测后者会出现更大的分层,显示了AP-PLY复合材料在提高低速冲击性能方面的潜力。Piezoresistivity Analyses of GNP-filled Composite Piezoresistor Under Cycling Loading and Correlation with The Monte Carlo Percolation ModelMelike Nur Önder, Mehmet Ali Gülgün, Melih Papiladoi:10.1016/j.compscitech.2024.110641 循环加载下gnp填充复合压敏电阻的压阻分析及其与蒙特卡罗渗流模型的相关性This paper presents a composite piezoresistor made of graphite paste and graphene nano-platelets (GNP). We focused on fluctuations in the gauge factor of piezoresistive composites and their dependence on the amplitude of strain cycles. A three-dimensional Monte Carlo percolation model was created. The model examines how the interactions between fillers and deformation-driven geometric changes could affect piezoresistivity. The present model of the composite piezoresistor simulates the percolation path for conduction through tunneling and capacitive interaction of particle pairs. Strain cycles of different amplitudes (loading parameter) and Poisson’s ratios (material parameter) are the variables of the analyses by the model. During the loading, the algorithm simulates the cross-sectional shrinkage of the matrix given the Poisson’s ratio. Shrinkage of the matrix enhances the conductance while the extension decreases it. Simulations demonstrated that the impact of the shrinkage on piezoresistivity varies with the amplitude of the strain. The results of the experimental plan for the composite piezoresistors are qualitatively in line with the simulations verifying the dominant influence of variations in extension/shrinkage amplitude as the main reason for a degrading gauge factor.本文介绍了一种由石墨糊和石墨纳米片(GNP)制成的复合压敏电阻。我们重点研究了压阻复合材料的应变系数波动及其与应变周期幅值的关系。建立了三维蒙特卡罗渗流模型。该模型考察了填料之间的相互作用和变形驱动的几何变化如何影响压电阻率。该复合压阻模型模拟了隧道传导的渗透路径和粒子对的电容性相互作用。不同幅值的应变循环(加载参数)和泊松比(材料参数)是模型分析的变量。在加载过程中,该算法在给定泊松比的情况下模拟了基体的截面收缩。基体的收缩提高了电导,而拉伸降低了电导。模拟结果表明,收缩对压阻率的影响随应变幅值的变化而变化。复合压敏电阻实验方案的结果与仿真结果在定性上一致,验证了扩展/收缩幅度的变化是导致测量因子退化的主要原因。来源:复合材料力学仿真Composites FEM

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