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【新文速递】2024年7月13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 4 篇,Composites Science and Technology 1 篇

Composite Structures

Stability of tensegrity-inspired structures fabricated through additive manufacturing

Anna Al Sabouni-Zawadzka, Wojciech Gilewski, Rana Nazifi Charandabi, Adam Zawadzki

doi:10.1016/j.compstruct.2024.118377

 

通过增材制造制造的张拉整体结构的稳定性

This study encompasses experimental and theoretical research on the stability of tensegrity-inspired structures in view of additive manufacturing technology. The aim of the research is to produce a qualitative and quantitative estimation of the post-critical behavior of struts in 3D-printed tensegrity-inspired modules. Presented results of compression tests performed on modules and single struts show that the bars work in the post-critical state before they reach their load bearing capacity. Comparison of theoretical solutions with experimental tests allowed us to conclude that the struts can carry axial loads significantly higher than the limits resulting from the classical Euler theory.

本研究包括增材制造技术下张拉整体结构稳定性的实验和理论研究。该研究的目的是对3d打印张拉整体启发模块中支柱的后临界行为进行定性和定量估计。对模块和单支杆进行的压缩试验结果表明,杆在达到其承载能力之前处于后临界状态。理论解与实验测试的比较使我们得出结论,支撑可以承受的轴向载荷明显高于经典欧拉理论的极限。


Composites Part A: Applied Science and Manufacturing

Harvesting tacit knowledge for composites workforce development

John Summerscales

doi:10.1016/j.compositesa.2024.108357

为复合材料劳动力开发获取隐性知识

Explicit knowledge can often be shared through textbooks, technical papers, instruction manuals, guides, and videos. It is normally objective, logical and technical. However, tacit (implicit) knowledge is any information or skills that arise from personal and professional experiences. It is often subjective, cognitive and experiential. When an individual leaves an organisation, they can take intellectual property with them that could compromise future operations, unless that knowledge is harvested. This brief review considers how transient knowledge might be retained in an organisation.

显性知识通常可以通过教科书、技术论文、指导手册、指南和视频进行共享。它通常是客观的、合乎逻辑的和技术性的。然而,隐性知识是来自个人和专业经验的任何信息或技能。它通常是主观的、认知的和经验的。当一个人离开一个组织时,他可能会带走知识产权,这可能会影响到未来的运营,除非他能收获这些知识。这篇简短的综述考虑了如何在组织中保留瞬时知识。


Composites Part B: Engineering

Development of the CaCO3-coated passive film on Mg alloy densified by glucose/sodium gluconate via the assistance of ultrasound with a regrowth feature in Portland cement

Ye Wang, Jingfeng Wang, Fusheng Pan

doi:10.1016/j.compositesb.2024.111719

超声辅助下葡萄糖/葡萄糖酸钠致密镁合金caco3包覆钝化膜在硅酸盐水泥中的再生特性研究

To address the limitations of non-dense chemical conversion coatings on Mg alloys, glucose and sodium gluconate were employed to facilitate the creation of dual-layered CaCO3 coated MgO passive layers via ultrasound-assisted chemical conversion. Results indicate that the addition of an appropriate quantity of glucose enhances the corrosion resistance of CaCO3/MgO coatings, whereas excessive glucose compromises coating density. Furthermore, higher concentrations of sodium gluconate contribute to improving coating density. Significantly, the immersion in simulated concrete pore solutions with 0.6M NaCl reveals a re-growth phenomenon instead of corrosion. This observation stems from the increased CaCO3 production, including calcite and aragonite during the immersion process.

为了解决镁合金非致密化学转化涂层的局限性,利用葡萄糖和葡萄糖酸钠通过超声辅助化学转化制备了双层CaCO3涂层MgO被动层。结果表明,添加适量的葡萄糖可以增强CaCO3/MgO涂层的耐腐蚀性,而过量的葡萄糖会降低涂层的密度。此外,较高的葡萄糖酸钠浓度有助于提高涂层密度。值得注意的是,0.6M NaCl浸泡在模拟混凝土孔隙溶液中,出现了再生长现象,而不是腐蚀。这一观察结果源于浸没过程中CaCO3产量的增加,包括方解石和文石。


Semi-destructive Methods for Evaluating the Micro-scale Residual Stresses of Carbon Fiber Reinforced Polymers

Wanying Zhao, Xiang Li, Jinrui Ye, Kai Liu, Xiangyu Xu, Zhanwei Liu

doi:10.1016/j.compositesb.2024.111722

 

评价碳纤维增强聚合物微尺度残余应力的半破坏性方法

Micro-scale residual stress in carbon fiber reinforced polymers have a significant impact on their mechanical performance. The residual stresses in the carbon fibers were released by micro-slotting and micro-ring-core methods using focused ion beam (FIB). The released deformation fields were captured by cross-gratings and mapped by geometric phase analysis (GPA) and digital image correlation (DIC) methods. The in-plane residual stresses in the carbon fibers were experimentally determined to be -40.5 MPa using elastic constitutive relations, which is consistent with the composites cylinder model. The axial compressive residual stresses in the fibers were found to be greater than -100 MPa. Moreover, the maximum value of residual stress in the polymer matrix was observed at the interface, potentially serving as a crack initiation site.

碳纤维增强聚合物的微尺度残余应力对其力学性能有重要影响。采用聚焦离子束(FIB)微开槽法和微环芯法释放碳纤维中的残余应力。通过交叉光栅捕获释放变形场,并通过几何相位分析(GPA)和数字图像相关(DIC)方法进行映射。利用弹性本构关系确定了碳纤维的面内残余应力为-40.5 MPa,与复合材料圆柱体模型一致。纤维的轴向残余压应力大于-100 MPa。此外,在界面处观察到聚合物基体中残余应力的最大值,这可能是裂纹起裂的部位。


In-situ nanoscale precipitation behavior and strengthening mechanism of WC/IN718 composites manufactured by laser powder bed fusion

Hongmei Zhang, Yujie Wu, Yi Wang, Weiwei Deng, Gang Xu, Kaiyu Luo, Jinzhong Lu

doi:10.1016/j.compositesb.2024.111727

激光粉末床熔覆WC/IN718复合材料的原位纳米析出行为及强化机理

Nickel matrix composites (NMCs) have received much attention as they show excellent high temperature performances, which could meet the demand for hot-end components in severe environments. In this study, the duplex in-situ nanoscale carbides and oxides reinforcing IN718 were fabricated by laser powder bed fusion (LPBF) and addition of submicron WC particles. The microstructural features and mechanical properties were investigated with variations of WC content (0, 0.5, 2, and 4wt.%). The columnar dendrites with strong <001> texture that boundary distributed continuous Laves phase were found in the LPBF-processed IN718. Incorporating WC led to higher laser absorption and processability, whereas it also decreased the anisotropy of the matrix featured by weak texture index. With an optimized content of 2wt.%, the WC was dissolved into W and C atoms under laser irradiation, which promoted the homogeneous precipitation of intergranular cubic (Nb, Ti)C (∼50 nm) and intragranular spherical Al2O3 (∼20 nm). These precipitates would for heterogenous nucleation to refine grains (∼12.6 μm) and bring about high-density dislocations. The yield strength (YS) and ultimate tensile strength (UTS) increased by 28.8% and 26.5%, respectively, while maintaining high elongation compared with reported NMCs, demonstrating a favorable strength-ductility combination. Finally, the mechanism of microstructure evolution and strengthening was elucidated.

镍基复合材料因其优异的高温性能,能够满足恶劣环境下热端部件的需求而备受关注。在本研究中,采用激光粉末床熔合(LPBF)和添加亚微米WC颗粒的方法制备了增强IN718的双相原位纳米碳化物和氧化物。研究了WC含量(0、0.5、2和4wt.%)变化时的微观组织特征和力学性能。在lpbf处理的IN718中发现了具有强<001>织构的柱状枝晶,具有边界分布的连续Laves相。WC的加入提高了激光吸收率和可加工性,同时降低了织构指数较弱的基体的各向异性。优化含量为2wt。%, WC在激光照射下溶解于W和C原子中,促进晶间立方(Nb, Ti)C (~ 50 nm)和晶内球形Al2O3 (~ 20 nm)的均匀析出。这些析出相使晶粒细化(~ 12.6 μm)并产生高密度位错。与已有报道的nmc相比,其屈服强度(YS)和极限抗拉强度(UTS)分别提高了28.8%和26.5%,同时保持了较高的延伸率,表现出良好的强度-塑性组合。最后,对微观组织演化和强化机理进行了探讨。


CNT modified chopped ultra-thin CF/PET tapes reinforced PET thermoplastic composite laminates with elevated interfacial properties and ultra-low porosity

Yang Guang, Cui Jinze, Zhang Simin, Kuang Xingwen, Luo Yutai, Bao Feng, Yu Jiali, Liu Huichao, Zhu Caizhen, Xu Jian

doi:10.1016/j.compositesb.2024.111718

 

碳纳米管改性短切超薄CF/PET带增强具有高界面性能和超低孔隙率的PET热塑性复合材料层合板

Carbon fiber (CF) reinforced thermoplastic polyethylene terephthalate (PET) laminate composites with light weight, high strength, excellent damage tolerance, and recyclability have garnered increasing attention. However, the weak interface between inert CF and PET resin, as well as the difficulty of impregnating the considerably high melt viscosity of PET matrix into the CF bundles, have impeded further development of the CF/PET composites. To settle the challenge, the chopped ultra-thin CF tapes (thickness of 40 μm and length of 30 mm) reinforced PET composite laminates were prepared by mechanical spreading technology, following with random stacking and molding technology via the plasma treatment and PET/carbon nanotubes (CNT) sizing. As a results, the optimal interlaminar shear strength (ILSS), tensile strength, and Young’s modulus of the chopped ultra-thin CF tapes reinforced PET composites (with 1.0 wt.% CNT) achieved 42.4 MPa, 780.9 MPa, and 47.8 GPa, which increased by 41.9%, 40.7%, and 68.9%, respectively, compared to unmodified CF/PET composites. Especially, the porosity of the composites reached 0.68%, decreased by 84.3%. Therefore, combining the easy infiltrability of chopped ultra-thin CF tapes technology and the multiscale interfacial reinforced strategy (plasma treatment and PET/CNT sizing) is an effective way to reduce the porosity and enhance the mechanical properties of the thermoplastic composites.

碳纤维(CF)增强热塑性聚对苯二甲酸乙二醇酯(PET)层压板复合材料具有重量轻、强度高、耐损伤性好、可回收性好等优点,越来越受到人们的关注。然而,惰性CF和PET树脂之间的弱界面,以及将相当高的熔融粘度的PET基体浸渍到CF束中的困难,阻碍了CF/PET复合材料的进一步发展。为了解决这一难题,采用机械铺层技术制备了厚度为40 μm、长度为30 mm的CF薄带增强PET复合材料层合板,然后通过等离子体处理和PET/碳纳米管(CNT)上浆,采用随机堆叠和成型技术制备了PET复合材料层合板。结果表明,与未改性的CF/PET复合材料相比,剪切超薄CF带增强PET复合材料(含1.0 wt.% CNT)的最佳层间剪切强度(ILSS)、抗拉强度(780.9 MPa)和杨氏模量(47.8 GPa)分别提高了41.9%、40.7%和68.9%。特别是复合材料的孔隙率达到0.68%,降低了84.3%。因此,将剪切超薄CF带的易渗透特性与多尺度界面增强策略(等离子体处理和PET/CNT上浆)相结合,是降低热塑性复合材料孔隙率、提高其力学性能的有效途径。


Composites Science and Technology

Novel computational model for the failure analysis of composite pipes under bending

Tianyu Wang, Oleksandr Menshykov, Marina Menshykova

doi:10.1016/j.compscitech.2024.110757

 

复合材料管道弯曲失效分析的新计算模型

This study presents a novel computational model to investigate the bending behaviour of thin- and thick-walled composite pipes made from fully bonded fibre-reinforced thermoplastic composite materials. The primary objective is to analyse the stress state and predict potential failure modes of these pipes, which have gained significant interest in the oil and gas industry due to their advantageous properties. The developed model is validated through comparisons with finite element analysis and published results, demonstrating its accuracy and adaptability. Utilizing the validated computational model, safety zones for composite pipes with various stacking sequences are established, providing valuable insights into the optimal design of composite pipes under bending loads. Furthermore, the method is employed to determine the maximum bending moment and critical bendable radius of the pipe, revealing the direct correlation between maximum bending moment and bending stiffness, independent of the bending radius. The findings of this study offer practical guidance for the design and optimisation of composite pipes in the oil and gas industry, promoting their adoption as a viable alternative to traditional metal pipes. The developed computational model serves as an efficient and reliable tool for engineers to make informed decisions in the design and selection of advanced composite materials for pipe applications, enabling the optimisation of pipe performance under various bending load scenarios.

本研究提出了一种新的计算模型来研究由全粘合纤维增强热塑性复合材料制成的薄壁和厚壁复合管材的弯曲行为。主要目的是分析这些管道的应力状态并预测其潜在的失效模式,这些管道因其优越的性能而引起了石油和天然气行业的极大兴趣。通过与有限元分析和已发表结果的比较,验证了所建模型的准确性和适应性。利用验证的计算模型,建立了复合材料管道在不同堆叠顺序下的安全区域,为复合材料管道在弯曲载荷下的优化设计提供了有价值的见解。利用该方法确定了管道的最大弯矩和临界弯曲半径,揭示了最大弯矩与弯曲刚度之间的直接关系,而与弯曲半径无关。该研究结果为油气行业复合管道的设计和优化提供了实用指导,促进了复合管道作为传统金属管道的可行替代品的采用。开发的计算模型是工程师在设计和选择先进复合材料时做出明智决策的有效可靠工具,可以优化管道在各种弯曲载荷情况下的性能。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveInspireDeform复合材料化学油气增材裂纹理论化机材料多尺度试验管道
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首次发布时间:2024-11-21
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【新文速递】2024年6月28日复合材料SCI期刊最新文章

今日更新:Composite Structures 9 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇Composite StructuresInvestigation of geometric and material effects on the fatigue performance of composite and steel adhesive jointsF.C. Sousa, A. Akhavan-Safar, R.J.C. Carbas, E.A.S. Marques, R. Goyal, J. Jennings, L.F.M. da Silvadoi:10.1016/j.compstruct.2024.118313复合材料和钢粘接接头疲劳性能的几何和材料影响研究This study experimentally investigates the combined effect of several parameters on the fatigue behaviour of adhesive bonded single lap joints, including: substrate material (steel, glass fibre reinforced polymer (GFRP) and carbon fibre reinforced polymer (CFRP)); adhesive material (epoxy and methacrylate); as well as joint geometry (overlap length and adhesive thickness). Results showed that despite the lower bulk strength of the ductile methacrylate adhesive, in terms of the ratio of fatigue load to ultimate failure load, joints bonded by this adhesive had a higher fatigue performance when compared to joints bonded by the epoxy one, with differences in fatigue life of up to 20 times for the same load ratio. In a similar substrate configuration, flexible GFRP substrates reduced the fatigue life of the joints bonded by the methacrylate adhesive more than 10 times when compared to steel joints for the same load. However, in a dissimilar configuration, an increase in fatigue life was observed which, based on a finite element analysis, was attributed to the ductility of the adhesive and its effects on the stress field. In CFRP joints bonded by the epoxy adhesive, a deterioration in fatigue performance was observed due to the occurrence of interfacial failure. Regarding the geometrical factors, increasing overlap length led to a decrease of the fatigue life for the same nominal shear stress. Similar trend was obtained for adhesive thickness. A parametric analysis revealed that overlap length is the parameter that affects more the fatigue performance of the joints.本研究通过实验研究了多个参数对粘合剂粘接单搭接接头疲劳性能的综合影响,包括:基材材料(钢、玻璃纤维增强聚合物(GFRP)和碳纤维增强聚合物(CFRP));粘合剂材料(环氧树脂和甲基丙烯酸酯);以及接头几何形状(重叠长度和粘合剂厚度)。结果表明,尽管韧性甲基丙烯酸酯粘合剂的体积强度较低,但就疲劳载荷与极限破坏载荷的比率而言,与环氧树脂粘合剂粘合的接头相比,这种粘合剂粘合的接头具有更高的疲劳性能,在相同载荷比率下,疲劳寿命最多相差 20 倍。在类似的基材配置中,柔性玻璃纤维增强塑料基材与相同载荷下的钢接头相比,甲基丙烯酸酯粘合剂粘合接头的疲劳寿命缩短了 10 倍以上。然而,在不同的结构中,观察到疲劳寿命增加,根据有限元分析,这归因于粘合剂的延展性及其对应力场的影响。在使用环氧树脂粘合剂粘合的 CFRP 接头中,由于出现界面破坏,疲劳性能有所下降。在几何因素方面,增加重叠长度会导致相同名义剪应力下的疲劳寿命缩短。粘合剂厚度也有类似的趋势。参数分析表明,重叠长度是对接头疲劳性能影响较大的参数。Predicting effective elastic modulus of CNT metal matrix nanocomposites: A developed micromechanical model with agglomeration and interphase effectsJavad Payandehpeyman, Mahdi Hedayatian, Mojtaba Mazaheridoi:10.1016/j.compstruct.2024.118317预测 CNT 金属基纳米复合材料的有效弹性模量:包含团聚和相间效应的微观力学模型Agglomeration and interphase region of fillers are two important factors that affect the mechanical properties of metal matrix composites reinforced with carbon nanotubes (CNT-CMMs). However, most of the existing theoretical models predict an ascending linear in strength for composites with increasing filler content, which disagrees with the experimental results, especially at high filler loading. In fact, at high CNT concentrations, agglomeration and weak interphase region bonding reduce the strength and consequently degrade the mechanical properties of composites. Based on the mean-field theory, we present a novel micromechanical model to predict the elastic modulus of CNT-CMMs by considering the effects of these two factors. Furthermore, we investigate the effect of other parameters such as CNTs aspect ratio, agglomeration amount, interphase layer thickness and modulus, and matrix modulus on the elastic modulus of CNT-CMMs. Finally, we validate our model by comparing it with numerous experimental outcomes from the literature signifies good precision. Using this model, it is possible to optimize the filler value and also maximize the elastic modulus, which can be a powerful tool for designing the CNT-CMMs.填料的团聚和相间区域是影响碳纳米管(CNT-CMMs)增强金属基复合材料机械性能的两个重要因素。然而,现有的大多数理论模型都预测,随着填料含量的增加,复合材料的强度呈线性上升趋势,这与实验结果不符,尤其是在填料含量较高的情况下。事实上,在 CNT 浓度较高的情况下,团聚和相间区域结合力较弱会降低强度,进而降低复合材料的机械性能。基于均场理论,我们提出了一种新型微机械模型,通过考虑这两个因素的影响来预测 CNT-CMM 的弹性模量。此外,我们还研究了其他参数对 CNT-CMM 弹性模量的影响,如 CNT 长径比、团聚量、相间层厚度和模量以及基体模量。最后,我们将模型与大量文献中的实验结果进行比较,验证了模型的精确性。利用该模型,可以优化填料值,同时最大限度地提高弹性模量,是设计 CNT-CMM 的有力工具。Buckling resistance of ultra-low-density carbon fiber curved-wall honeycomb based on stretching processXiaojian Chen, Ziqi Chu, Weikai Zhao, Linzhi Wu, Qianqian Wu, Guocai Yudoi:10.1016/j.compstruct.2024.118322基于拉伸工艺的超低密度碳纤维曲壁蜂窝的抗弯曲性能Although honeycomb is a kind of lightweight structural material with great potential, its specific strength is not always able to meet the requirements, especially in the weight-sensitive field. Inspired by the bionic idea of cuttlebone, the curved-wall configuration design is proposed to strengthen the buckling impedance of honeycomb, which can effectively prevent the premature occurrence of buckling failure mode induced by thin walls. Compared with the straight-wall honeycomb materials of the same geometric size, the probability of buckling failure in curved-wall honeycomb materials proposed in this paper is reduced by more than 22 %. Moreover, to achieve the preparation of curved-wall configuration, a processing strategy that uses stretching process to prepare ultralight carbon fiber honeycomb (Carbcomb) material is firstly introduced. Compared to the Hexcel Corporation’s aluminum honeycomb with a density of 21 kg/m3, for the Carbcomb, the specific compressive strength and specific shear strength along both the L and W directions respectively improved by 57 %, 61 % and 77 %. In addition, the minimum density of fabricated Carbcomb (14.6 kg/m3) is less than that of the Hexcel&#39;s products (16 kg/m3), and the research findings fill the gap of the carbon fiber honeycomb material in low density areas (10 ∼ 30 kg/m3). More importantly, this process which does not require much manual operation can effectively avoid the problems of unstable mechanical properties, difficult mass production and high preparation cost of the existing carbon fiber structural parts. This curved-wall configuration design and fabricated approach widens the potential of carbon fiber honeycomb as a structural material, and makes it possible for lower cost and higher efficiency in aerospace and transportation applications.虽然蜂窝是一种潜力巨大的轻质结构材料,但其比强度并不总是能满足要求,尤其是在对重量敏感的领域。受海螵蛸仿生学思想的启发,我们提出了弧形壁配置设计,以增强蜂窝的屈曲阻抗,从而有效防止因壁薄而过早出现屈曲失效模式。与相同几何尺寸的直壁蜂窝材料相比,本文提出的曲壁蜂窝材料的屈曲失效概率降低了 22% 以上。此外,为实现弧壁结构的制备,首先介绍了一种采用拉伸工艺制备超轻碳纤维蜂窝材料(Carbcomb)的加工策略。与 Hexcel 公司密度为 21 kg/m3 的铝蜂窝材料相比,Carbcomb 材料沿 L 和 W 方向的比压缩强度和比剪切强度分别提高了 57%、61% 和 77%。此外,Carbcomb 的最小密度(14.6 千克/立方米)低于 Hexcel 的产品(16 千克/立方米),该研究成果填补了碳纤维蜂窝材料在低密度领域(10 ∼ 30 千克/立方米)的空白。更重要的是,这种不需要太多人工操作的工艺能有效避免现有碳纤维结构件机械性能不稳定、难以批量生产、制备成本高等问题。这种弧形壁构造设计和制造方法拓宽了碳纤维蜂窝作为结构材料的潜力,使其在航空航天和交通运输领域的低成本、高效率应用成为可能。Experimental and numerical study of resin permeation effect on ballistic behavior of fabric laminateYanfei Yang, Junzhi Liu, Wanwan Cao, Dongsheng Maodoi:10.1016/j.compstruct.2024.118327树脂渗透对织物层压板弹道行为影响的实验和数值研究This study aims to identify the influence of resin permeation on ballistic responses of fabric laminates. According to experimental results, when the resin permeation degree was improved, the yarn mobility was greatly constrained due to increasing of the bonding force, and the specific energy absorption of laminates under ballistic impact was degraded in comparison with that of the neat fabric. Different resin permeation states in a single yarn and fabric were simulated through Finite Element (FE) modeling at a fiber-bundle level. For a given resin ratio of 15%, semi-permeation of resin in a single yarn was benefit for energy absorption due to even distribution of impact load at the early impact, but full-permeation of resin resulted in energy absorption degradation due to high stress concentration and premature failure. For laminate models, the yarn mobility was severely constrained not only by resin bonding but also by yarns interlacement. In comparison with the neat fabric, stress distribution area on laminates was decreased 30–70%. Yarns contribution to energy absorption was significantly reduced in particular for principal yarns. Such results indicated that perfect resin permeation in armor-grade composite played a negative effect on ballistic energy dissipation due to low material utilization efficiency.本研究旨在确定树脂渗透对织物层压板弹道响应的影响。实验结果表明,当树脂渗透度提高时,由于粘合力的增加,纱线的流动性受到很大限制,层压织物在弹道冲击下的比能量吸收与纯织物相比有所下降。通过有限元(FE)建模,在纤维束水平上模拟了单根纱线和织物中不同的树脂渗透状态。在给定的 15% 树脂比率下,单根纱线中的半渗透树脂有利于吸收能量,因为在早期冲击时冲击载荷分布均匀,但全渗透树脂则会导致能量吸收能力下降,因为应力集中和过早失效。对于层压模型,纱线的流动性不仅受到树脂粘合的严重限制,还受到纱线交错的限制。与纯织物相比,层压板上的应力分布面积减少了 30-70%。纱线对能量吸收的贡献明显降低,尤其是主纱。这些结果表明,由于材料利用效率低,装甲级复合材料中的完美树脂渗透对弹道能量耗散产生了负面影响。Self-driven intelligent curved hinge based on shape-morphing compositesXiaozhou Xin, Cheng Lin, Bingxun Li, Chengjun Zeng, Liwu Liu, Yanju Liu, Jinsong Lengdoi:10.1016/j.compstruct.2024.118329基于形状变形复合材料的自驱动智能曲面铰链The space deployable structures based on shape memory polymer composites (SMPCs) possessed excellent self-deployable performance, which effectively avoided the impact and electromagnetic pulse (EMP) caused by the explosion of pyrotechnic devices. In this work, two types of self-driven curved hinges with different angles of 80° and 115° (Type 80 and Type 115) were designed based on SMPCs. The thermomechanical properties and time–temperature-dependent viscoelastic behaviors of SMPCs were systematically investigated. The three-point bending performance and cyclic shape memory performance of the developed hinges were also characterized. In addition, the deployment performances of Type 80 driven 350 g object under different heating powers were investigated in the environment of ± 70 °C and 103 Pa atmospheric pressure. A staircase-like heating strategy was proposed to achieve precise and controllable deployment under this environment. The developed self-driven curved hinges were expected to have tremendous application potential on the flap actuators and optical payload rotating platforms of the satellites.基于形状记忆聚合物复合材料(SMPCs)的空间可部署结构具有优异的自部署性能,可有效避免烟火装置爆炸造成的冲击和电磁脉冲(EMP)。本研究以 SMPC 为基础,设计了 80° 和 115° 两种不同角度的自驱动弧形铰链(80 型和 115 型)。系统研究了 SMPC 的热力学性质和随时间变化的粘弹性行为。还对所开发铰链的三点弯曲性能和循环形状记忆性能进行了表征。此外,在 ± 70 °C 和 103 Pa 气压环境下,研究了不同加热功率下 80 型驱动 350 g 物体的展开性能。为了在这种环境下实现精确和可控的展开,提出了一种阶梯式加热策略。所开发的自驱动弧形铰链有望在卫星的襟翼致动器和光学有效载荷旋转平台上发挥巨大的应用潜力。Deterioration of carbon fiber/matrix interface in humid environments and influence of silicon coupling agent modification: An atomistic investigationWangdong Guan, Bin Luo, Wei Han, Haoyuan Suo, Yingjie Niu, Zhaohui Wei, Hui Chengdoi:10.1016/j.compstruct.2024.118330潮湿环境中碳纤维/基质界面的劣化及硅偶联剂改性的影响:原子研究Extended exposure to moisture could harm the carbon fiber/matrix interface, threatening CFRP’s reliability service. This paper introduces a method that develops molecular dynamics models to analyze the deterioration of the interface and the influence of the silicon coupling agent. The mechanical properties of the interface in humid environments are obtained through simulations. The interfacial shear strength decreases by 25.68% and 26.96% respectively, demonstrating good consistency between experiment and simulation. The free volume and water distribution function characterize the extent of interface deterioration under varying moisture levels. The water molecules weak interface interactions through hydrogen bonding, leading to abnormal swelling of nanoscale structure. This inhibits the stress transfer between the fiber and matrix, weakening the interfacial shear strength. Additionally, the silane coupling agent reduces the pathway for water transmission, diminishing water diffusion. It can enhance the water damage resistance capability of interfacial strength.长时间暴露在潮湿环境中会损害碳纤维/基体界面,威胁 CFRP 的可靠性。本文介绍了一种建立分子动力学模型来分析界面劣化和硅偶联剂影响的方法。通过模拟获得了界面在潮湿环境中的机械性能。界面剪切强度分别降低了 25.68% 和 26.96%,实验与模拟结果具有良好的一致性。自由体积和水分分布函数表征了界面在不同湿度下的劣化程度。水分子通过氢键削弱了界面相互作用,导致纳米结构异常膨胀。这抑制了纤维与基体之间的应力传递,削弱了界面剪切强度。此外,硅烷偶联剂还能减少水的传播途径,降低水的扩散。它可以增强界面强度的抗水损能力。A diffusion–reaction-deformation cohesive interface for oxidization and self-healing of PyC/SiC interfacial coatingLizhenhui Zhou, Wenyang Liu, Yiqi Mao, Shujuan Houdoi:10.1016/j.compstruct.2024.118332用于 PyC/SiC 界面涂层氧化和自修复的扩散-反应-变形内聚界面This paper presents a fully coupled thermodynamically consistent diffusion–reaction-deformation cohesive model for pyrolytic carbon (PyC)/SiC interfacial coating in fiber-reinforced composites. Arrhenius function is used to capture the chemical kinetics and the Kuhn-Tucker conditions is exploited to describe the damage evolution of interfacial coating. A strong connection between the diffusion–reaction process and interfacial mechanical deformation is established by the cohesive model, and the rules of the model parameters are discussed in detail. Implementation of the cohesive zone model is conducted in ABAQUS finite element software through the use of UEL subroutines. A mesh convergence for the model is tested and the model is validated by the comparison with the experimental results. A Representative Volume Element (RVE) model for fiber-reinforced composites at different temperatures, equipped with custom cohesive elements, is constructed to investigate the impact of PyC/SiC coating during oxidation. Two-step simulation is adopted to solve the chemo-mechanical behaviors of interfacial coating.The impact of the interfacial coating on stress transfer between the matrix and fibers is highlighted by numerical results that demonstrate an initial decline in mechanical properties followed by an upward trend with increasing temperature. The model also captures the coupling mechanisms between the diffusion–reaction process and the interfacial deformation in the interfacial coating. Theoretical insights for fiber-reinforced composites in chemical environments are provided, guiding the design of interfacial coatings for potential engineering applications.本文针对纤维增强复合材料中热解碳(PyC)/碳化硅(SiC)界面涂层提出了一种完全耦合的热力学一致的扩散-反应-变形内聚模型。阿伦尼乌斯函数用于捕捉化学动力学,库恩-塔克条件用于描述界面涂层的损伤演变。内聚模型建立了扩散反应过程与界面机械变形之间的紧密联系,并详细讨论了模型参数的规则。通过使用 UEL 子程序,在 ABAQUS 有限元软件中实现了内聚区模型。对模型的网格收敛性进行了测试,并通过与实验结果的对比对模型进行了验证。为研究氧化过程中 PyC/SiC 涂层的影响,构建了不同温度下纤维增强复合材料的代表体积元素(RVE)模型,并配备了定制的内聚元素。采用两步模拟法求解界面涂层的化学机械行为。数值结果突出显示了界面涂层对基体和纤维之间应力传递的影响,这些结果表明随着温度的升高,机械性能最初会下降,随后呈上升趋势。该模型还捕捉到了扩散-反应过程与界面涂层中界面变形之间的耦合机制。该模型为化学环境中的纤维增强复合材料提供了理论依据,为潜在工程应用中的界面涂层设计提供了指导。Closed-form analytical relationships for pentamode metamaterialsReza Hedayati, Kaivan Mohammadi, Sattar Jedari Salami, Nima Roudbarian, Pooyan Nayyeri, Mohamad Mahdi Rafiee, Habiba Bougheraradoi:10.1016/j.compstruct.2024.118334五模超材料的闭式分析关系Pentamode metamaterials are a class of extremal materials exhibiting fluid-like mechanical behavior. The mechanical properties of pentamode metamaterials arise from their unique micro-architecture, rather than their constituent material. In this research, we present closed-form analytical relationships for the elastic modulus and Poisson’s ratio of pentamode lattice structures with double-cone struts based on cubic diamond morphology. To validate our analytical solutions, we performed numerical simulations and experimental tests, which confirmed the accuracy of the derived relationships. Our findings indicate that increasing the smaller diameter (d) and the larger-to-smaller diameter ratio (α) of the double-cones increases the elastic modulus of pentamode metamaterials. However, within the considered range of d and α, the Poisson’s ratio is nearly constant and lies within the range of approximately 0.5. These analytical relationships provide valuable insight into the mechanical behavior of pentamode metamaterials, which can aid in the design and optimization of new materials with unique properties.五模超材料是一类表现出类似流体力学行为的极端材料。五模超材料的机械特性源于其独特的微结构,而非其组成材料。在这项研究中,我们基于立方钻石形态,提出了具有双锥支柱的五模晶格结构的弹性模量和泊松比的闭式分析关系。为了验证我们的分析解,我们进行了数值模拟和实验测试,证实了推导关系的准确性。我们的研究结果表明,增大双锥的小直径(d)和大-小直径比(α)会增加五模超材料的弹性模量。然而,在考虑的 d 和 α 范围内,泊松比几乎是恒定的,大约在 0.5 的范围内。这些分析关系为五模超材料的机械行为提供了宝贵的见解,有助于设计和优化具有独特性能的新材料。A finite difference method on crack resistance of reinforced glass beam with non-linear adhesiveDejun ZHANG, Suwen CHENdoi:10.1016/j.compstruct.2024.118335采用非线性粘合剂的钢筋玻璃梁抗裂性有限差分法Reinforced glass beam (RG beam) is a type of structural glass member that has been developed in recent years. This RG beam consists of a glass beam to which reinforcement material, such as steel, is adhesively attached in the tensile side to improve crack resistance. The adhesive plays a critical role in the structural performance of RG beam. However, the effect of non-linear shear-slip behavior of the adhesive layer remains unclear and has been neglected in most previous studies, which can result in inaccurate estimations. To address this issue, this paper presents a finite difference model (FDM) that utilizes an explicit step-by-step method and trial-and-error iterative method for interfacial stress analysis. The model predicts the static structural response of a simply-supported RG beam that simulates the adhesive with non-linear stress-slip behavior. Furthermore, the model describes the adherend’s shear deformation in elastic. The FDM results are then compared with the finite element method (FEM), adopting discrete nonlinear connectors (springs) to simulate the adhesion, and available analytical methods. Detailed parametric studies are further conducted to investigate the influences of glass strength, load pattern, reinforcement ratio and height-to-span ratio for proposing design recommendations.强化玻璃梁(RG 梁)是近年来开发的一种玻璃结构构件。这种 RG 梁由玻璃梁组成,在玻璃梁的抗拉一侧粘附有钢筋等加固材料,以提高抗裂性能。粘合剂对 RG 梁的结构性能起着至关重要的作用。然而,粘合剂层的非线性剪切-滑移行为的影响仍不明确,而且在之前的大多数研究中都被忽略了,这可能会导致不准确的估算。为解决这一问题,本文提出了一种有限差分模型(FDM),利用显式分步法和试错迭代法进行界面应力分析。该模型预测了简单支撑 RG 梁的静态结构响应,模拟了具有非线性应力-滑动行为的粘合剂。此外,该模型还描述了粘合剂的弹性剪切变形。然后,将 FDM 结果与采用离散非线性连接器(弹簧)模拟粘合的有限元法(FEM)和现有的分析方法进行比较。还进一步进行了详细的参数研究,以调查玻璃强度、载荷模式、加固比和高度跨度比的影响,从而提出设计建议。Composites Part A: Applied Science and ManufacturingGeometry and temperature effects on tensile properties and failure behaviors of open-hole and bolted-joint CF/PEKK compositesXiaoqi Li, Sanjay Kumar, Dong-Wook Hwang, Do-Hoon Shin, Sung-Youl Bae, Yun-Hae Kimdoi:10.1016/j.compositesa.2024.108336几何形状和温度对开孔和螺栓连接 CF/PEKK 复合材料拉伸性能和破坏行为的影响Temperature-dependent tensile properties of carbon-fiber-reinforced polyetherketoneketone (CF/PEKK) composites with varying width-to-diameter (W/D) ratios in open-hole (OH) and bolted joint (BJ) were investigated. CF/PEKK exhibited higher modulus and strength at lower temperature due to restricted polymer chain mobility, and lower values at elevated temperature due to increased polymer ductility. OH net tensile strength decreased with decreasing W/D, with strain retention dropping significantly at W/D≤ 2. The approximate average strain concentration factor determined from digital image correlation slightly exceeded theoretical values due to semi-crystalline nature of PEKK. Distinct failure behaviors highlighting the complex interplay between temperature, W/D, and failure characteristics. Evaluating W/D and temperature effects on BJ CF/PEKK revealed changing failure modes. Bolted joint efficiency emphasizing the need to optimize W/D ratios above 2 to achieve high efficiency. These findings highlight the geometry and temperature interplay affects CF/PEKK composites, which are crucial for designing high-performance materials, especially for aerospace applications.研究了不同宽径比(W/D)的碳纤维增强聚醚醚酮(CF/PEKK)复合材料在开孔(OH)和螺栓连接(BJ)中随温度变化的拉伸性能。由于聚合物链的流动性受到限制,CF/PEKK 在低温下表现出较高的模量和强度,而在高温下由于聚合物延展性增加,模量和强度值较低。OH 净拉伸强度随着 W/D 的减小而降低,W/D≤2 时应变保持率显著下降。由于 PEKK 的半结晶性质,通过数字图像相关性确定的近似平均应变集中因子略微超出理论值。不同的失效行为突显了温度、W/D 和失效特性之间复杂的相互作用。评估 W/D 和温度对 BJ CF/PEKK 的影响揭示了不断变化的失效模式。螺栓连接效率强调了优化 W/D 比(2 以上)以实现高效率的必要性。这些发现突显了几何形状和温度相互作用对 CF/PEKK 复合材料的影响,这对于设计高性能材料,尤其是航空航天应用至关重要。Composites Part B: EngineeringHighly Stretchable and Conductive Kirigami-like Double-layer Electrodes for Motion-insensitive Wearable ElectronicsWoosik Kim, Junsung Bang, Yoonji Yang, Tae Hee Ko, Moonseok Jang, Jung-Joon Cha, Jong-Il Choi, Soong Ju Ohdoi:10.1016/j.compositesb.2024.111655 用于运动敏感型可穿戴电子设备的高弹性和导电性桐藻状双层电极The development of motion-insensitive electronic devices capable of maintaining consistent performance during bending, twisting, and stretching movements of the human skin is crucial for realizing wearable sensor systems. Various approaches for creating stretchable electrodes for wearable device fabrication have been exploited; however, the simultaneous achievement of high stretchability and conductivity in an electrode remains challenging. In this study, we propose styrene-ethylene-butylene-styrene-based highly stretchable and conductive double-layer electrodes that have a kirigami structure that promotes conductivity preservation. Ag nanowires (NWs) and an Au double-layer film exhibited a low sheet resistance of 7.6 Ω/sq and maintained conductivity even at a maximum tensile strain of 350 %. The electrodes demonstrated consistent current responses after 1000 cycles of testing and maintained reliable electronic device performance under motion-induced conditions such as bending, twisting, and stretching. Electrocardiogram (ECG) sensing was conducted to monitor the heart rate of the mouse with strain applied to the electrode. Morphological analysis revealed that the Au film dispersed the stress uniformly across the entire film during stretching, and the Ag NWs suppressed microcrack propagation, demonstrating the contribution of the kirigami structure and the resulting stretching mechanism toward the significant enhancement of stretchability. The highly conductive and stretchable electrodes developed in this study promote the development of high-performance wearable electronics that can function under highly flexible conditions.开发能够在人体皮肤弯曲、扭转和拉伸运动中保持稳定性能的运动敏感型电子器件,对于实现可穿戴传感器系统至关重要。目前已开发出多种用于制造可穿戴设备的可拉伸电极的方法;然而,在电极中同时实现高拉伸性和导电性仍然具有挑战性。在本研究中,我们提出了基于苯乙烯-乙烯-丁烯-苯乙烯的高拉伸性和导电性双层电极,这种电极具有促进导电性保持的叽里格米结构。银纳米线(NWs)和金双层薄膜具有 7.6 Ω/sq 的低薄层电阻,即使在最大拉伸应变为 350 % 时也能保持导电性。经过 1000 次循环测试后,电极显示出一致的电流响应,并在弯曲、扭转和拉伸等运动条件下保持可靠的电子器件性能。通过心电图(ECG)传感技术监测了电极应变时小鼠的心率。形态学分析表明,金薄膜在拉伸过程中将应力均匀地分散到整个薄膜上,而Ag NWs则抑制了微裂纹的扩展,这证明了叽里格米结构和由此产生的拉伸机制对显著提高拉伸性的贡献。本研究开发的高导电性和可拉伸电极促进了可在高柔性条件下工作的高性能可穿戴电子设备的开发。Composites Science and TechnologyDynamic strengthening of UHMWPE yarns by incorporating ZrO2/PU coatingsHaoxiang Wang, Yue Shen, Jian Wei, Yu Long, Jiagui Liu, Biwei Deng, Zhongwei Zhang, Ziming Xiong, Fan Wu, Tian Jian Lu, Han Meng, Feng Chen, Jinling Gaodoi:10.1016/j.compscitech.2024.110730 通过加入 ZrO2/PU 涂层实现超高分子量聚乙烯纱线的动态强化Wrapping is an effective technique for reducing defects in fabric weaving and promoting even wetting in composite manufacturing, which is potential to enhance the impact resistance of armor materials. In this study, we impregnated UHMWPE yarns with a polyurethane (PU) compound and cured them to create composite yarns, and ZrO2 was introduced to improve the toughness. The microstructures were analyzed using three-dimensional X-ray computed tomography, optical microscopy, and scanning electron microscopy (SEM). Quasi-static and dynamic tensile experiments were conducted using a universal testing machine and Kolsky tension bar, respectively. High-speed imaging was used to capture the real-time failure process, and post-fracture analysis was performed to examine the fracture morphology. The effects of strain rate, gauge length, and the presence of PU and ZrO2 on the mechanical behavior of the yarns were investigated. The results showed that the peak force of the composite yarns with PU coatings exhibited strain-rate dependency at low strain rates (below 4.4 × 10-2 s-1) but became insensitive to strain rate in the higher range of 4.4 × 10-2 s-1 to 1500 s-1. Furthermore, the introduction of ZrO2 effectively increased the peak force, potentially by strengthening the bonding between individual fibers within the yarn.包覆是一种有效的技术,可减少织物编织过程中的缺陷,促进复合材料制造过程中的均匀润湿,从而提高装甲材料的抗冲击性。在这项研究中,我们用聚氨酯(PU)化合物浸渍超高分子量聚乙烯(UHMWPE)纱线并将其固化,从而制造出复合纱线,并引入 ZrO2 来提高韧性。使用三维 X 射线计算机断层扫描、光学显微镜和扫描电子显微镜分析了微观结构。分别使用万能试验机和 Kolsky 拉伸杆进行了准静态和动态拉伸实验。采用高速成像技术实时捕捉断裂过程,并进行断裂后分析以检查断裂形态。研究了应变速率、轨距长度以及 PU 和 ZrO2 的存在对纱线机械行为的影响。结果表明,带有聚氨酯涂层的复合纱线的峰值力在低应变速率(低于 4.4 × 10-2 s-1)时表现出应变速率依赖性,但在 4.4 × 10-2 s-1 至 1500 s-1 的较高应变速率范围内变得对应变速率不敏感。此外,ZrO2 的引入有效地提高了峰值力,这可能是通过加强纱线内单根纤维之间的粘合力实现的。来源:复合材料力学仿真Composites FEM

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