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【新文速递】2024年1月31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 5 篇,Composites Part B: Engineering 8 篇,Composites Science and Technology 2 篇

Composite Structures

Carrera Unified Formulation (CUF) for the Composite Plates and Shells of Revolution. Layer-Wise Models

E. Carrera, V.V. Zozulya

doi:10.1016/j.compstruct.2024.117936

旋转板壳复合材料的Carrera统一公式。Layer-Wise模型

Here, higher order layer-wise models of elastic composite multilayer plates and shells of revolution are developed using the variational principle of virtual power for the 3-D linear anisotropic theory of elasticity and generalized series in the thickness coordinates. Following the Unified Carrera Formulation (CUF), the stress and strain tensors, as well as the displacement vector, were expanded into series in terms of the coordinates of the shell thickness. The higher-order rectangular plate and cylindrical shell supported on the edges under sinusoidal loading, are considered and solved analytically using a Navier close form solution method. Also, composite axisymmetric conical, spherical, elliptical and catenoidal shell fixed at the ends are considered. Numerical calculations were performed using the computer algebra software Mathematica. The resulting equations can be used for theoretical analysis and calculation of the stress-strain state, as well as for modeling thin-walled structures used in science, engineering, and technology. The results of calculation can be used as benchmark examples for finite element analysis of the higher order composite laminate shells.

本文利用三维线性各向异性弹性理论的虚功率变分原理和厚度坐标下的广义级数,建立了弹性复合材料多层板壳旋转的高阶分层模型。根据统一卡雷拉公式(CUF),应力和应变张量以及位移矢量按壳体厚度坐标展开成级数。考虑正弦载荷作用下的高阶矩形板和边缘支承圆柱壳,采用Navier闭合解方法进行解析求解。此外,还考虑了两端固定的复合轴对称圆锥壳、球形壳、椭圆形壳和链状壳。采用计算机代数软件Mathematica进行数值计算。所得方程可用于应力应变状态的理论分析和计算,也可用于科学、工程和技术中薄壁结构的建模。计算结果可作为高阶复合材料层合壳有限元分析的基准算例。


Composites Part A: Applied Science and Manufacturing

A state-rate model for the transient wall slip effects in ply-ply friction of UD C/PAEK tapes in melt

E.R. Pierik, W.J.B. Grouve, S. Wijskamp, R. Akkerman

doi:10.1016/j.compositesa.2024.108040

熔体中UD C/PAEK带层间摩擦瞬态壁滑效应的状态-速率模型

Ply-ply slippage is one of the key deformation mechanisms occurring during hot press-forming of thermoplastic composite laminates. Advanced forming simulations, required for defect-free manufacturing, rely on accurate constitutive models for these deformation mechanisms. In this work, we propose a relative simple, yet accurate, transient model to describe the start-up friction response of UD C/PAEK tapes. The model combines a White-Metzner viscoelastic fluid with a state-rate model for the evolution of wall slip near the fiber–matrix interface, describing the disentanglement of surface polymer chains followed by the settlement of these chains in a new equilibrium state. This allows prediction of the stress growth at start-up and the transition from peak to steady-state friction, from smooth to sharp with increasing sliding rate, as well as the magnitude of the peak and steady-state friction. We obtained a good correlation between the modeled and measured friction response for different sliding rates.

层间滑移是热塑性复合材料层压板热压成形过程中发生的主要变形机制之一。先进的成形模拟,需要无缺陷的制造,依赖于这些变形机制的准确本构模型。在这项工作中,我们提出了一个相对简单但准确的瞬态模型来描述UD C/PAEK胶带的启动摩擦响应。该模型结合了White-Metzner粘弹性流体和纤维-基质界面附近壁滑移演化的状态-速率模型,描述了表面聚合物链的解缠以及这些链在新的平衡状态下的沉降。这可以预测启动时的应力增长,从峰值到稳态摩擦的转变,随着滑动速率的增加,从平滑到急剧的转变,以及峰值和稳态摩擦的大小。在不同的滑动速率下,我们得到了模型和实测摩擦响应之间良好的相关性。


Magnetic Quantum Dots Modified Hollow Carbon Spheres and Controllable Electromagnetic wave Absorption Performance

Yiqiang Liu, Jiabin Yao, Zhihao Shen, Mingju Zhang, Dongwei Xu, Ping Chen

doi:10.1016/j.compositesa.2024.108056

磁量子点修饰的空心碳球及其可控电磁波吸收性能

Carbon-based materials owing to their customizable dielectric loss and the light weight characteristic have become increasingly popular as microwave absorption materials. However, due to the weak loss property and the poor impedance matching, the absorbing performance especially the absorption bandwidth is not satisfactory. Herein, magnetic quantum dots modified hollow carbon microspheres were constructed through structural design, interface regulation and magnetization strategies. The hollow structure significantly facilitated the impedance matching and the reduction of weight. Synchronously, the introduction of the magnetic quantum dots endowed the composites with excellent magnetic response. As a result, the as-obtained composites delivered an effective absorption bandwidth of 6.6 GHz with a thickness of 2.4 mm. Moreover, the composites exhibited an ultra-wide effective absorption band of 8.0 GHz (10-18 GHz) with a matching thickness of 2.6 mm. Thus, the proposed strategy shed new lights on the design, synthesis, and performance regulation of lightweight broadband microwave absorption materials.

碳基材料由于其可定制的介电损耗和重量轻的特点,成为越来越受欢迎的微波吸收材料。但由于其损耗特性较弱,阻抗匹配较差,导致其吸收性能尤其是吸收带宽不理想。通过结构设计、界面调节和磁化策略,构建了磁性量子点修饰的空心碳微球。空心结构明显有利于阻抗匹配和减轻重量。同时,磁性量子点的引入使复合材料具有优异的磁响应性能。结果表明,复合材料的有效吸收带宽为6.6 GHz,厚度为2.4 mm。此外,复合材料具有8.0 GHz (10-18 GHz)的超宽有效吸收带,匹配厚度为2.6 mm。因此,提出的策略为轻型宽带微波吸收材料的设计、合成和性能调节提供了新的思路。


Synthesis of zirconium aminotrimethylene phosphonate nanorods and their application in toughened and flame retarded epoxy composites

Xin Wang, Jie Zhang, Xian-Ling Fu, Fu-Kai Chu, Yuan Hu

doi:10.1016/j.compositesa.2024.108059

氨基膦酸三亚甲基锆纳米棒的合成及其在增韧阻燃环氧复合材料中的应用

Nanocomposite technology is the most promising strategy to synchronously improve the mechanical properties and flame retardancy of polymer materials. In this study, zirconium aminotrimethylene phosphonate (ZrATMP) nanorods were synthesized from amino tris(methylene phosphonic acid) and added to epoxy resin (EP) to further prepare ZrATMP-EP composites. Compared with those of pure EP, the peak heat release rate, total heat release, total smoke release, and peak CO production rate of the 3 wt% ZrATMP-EP composite decreased by 30.4%, 39.2%, 23.1%, and 47.3%, respectively. This was because Lewis acid sites on the ZrATMP nanorods catalyzed the carbonization of the EP matrix to form a dense protective char layer. Additionally, the tensile and impact strengths of 3 wt% ZrATMP-EP were 110.7% and 75.5% greater than those of pure EP, respectively. ZrATMP nanorods are a new class of flame retardant additive because of the simultaneous improvements in fire safety and mechanical strength of polymers.

纳米复合技术是同步提高高分子材料力学性能和阻燃性的最有前途的方法。本研究以氨基膦酸为原料合成氨基膦酸三甲基锆(ZrATMP)纳米棒,并将其加入环氧树脂(EP)中,进一步制备ZrATMP-EP复合材料。与纯EP相比,3 wt% ZrATMP-EP复合材料的峰值放热率、总放热率、总排烟率和峰值CO产率分别降低了30.4%、39.2%、23.1%和47.3%。这是因为ZrATMP纳米棒上的Lewis酸位点催化了EP基体的碳化,形成了致密的保护炭层。3 wt% ZrATMP-EP的拉伸强度和冲击强度分别比纯EP高110.7%和75.5%。ZrATMP纳米棒是一种新型的阻燃添加剂,因为它同时提高了聚合物的防火安全性和机械强度。


Preparation of “core-shell” structured SiO2@TiO2 nanospheres by in-situ polymerization and grafting modification method for enhancing fluororubber’s mechanical performance

Zhukang Bai, Yadong Wu, Jun Li, Wang Shun, Xuqiang Peng, Huile Jin

doi:10.1016/j.compositesa.2024.108060

原位聚合和接枝改性法制备核壳结构SiO2@TiO2纳米微球以提高氟橡胶的力学性能

To attain the high dispersion and strong interfacial bonding of TiO2 in fluororubber (FKM), a novel “core–shell” structured SiO2@TiO2 nanofillers was designed and synthesized by in-situ polymerization and grafting modification method. For the “core–shell” structured SiO2@TiO2 nanospheres, the rough and irregular silica shell can improve the surface area of the SiO2@TiO2 filler and realize the mechanical riveting with the FKM, which shows a significant mechanical properties enhancement function. Compared with the pristine FKM, the tear strength, tensile strength, hardness, modulus at 100% strain, modulus at 300% strain, and storage modulus at −100 °C of FKM/SiO2@TiO2 enhanced by 42.4%, 196.9%, 10%, 24.4%, 66.7%, and 15.5%, respectively. The sample’s electrical, thermal, and color properties were also improved and showed the highest haze and lowest light transmissions. Such a simple and effective method of preparing “core–shell” structured SiO2@TiO2 nanofillers provides great potential in industrial applications.

为了使TiO2在氟橡胶(FKM)中具有高分散性和强界面键合性,采用原位聚合和接枝改性的方法,设计并合成了一种新型的“核-壳”结构SiO2@TiO2纳米填料。对于“核-壳”结构SiO2@TiO2纳米球,粗糙和不规则的硅壳可以提高SiO2@TiO2填料的表面积,实现与FKM的机械铆接,表现出明显的力学性能增强功能。与原始FKM相比,FKM/SiO2@TiO2的撕裂强度、抗拉强度、硬度、100%应变模量、300%应变模量和−100 °C下的存储模量分别提高了42.4%、196.9%、10%、24.4%、66.7%和15.5%。样品的电学、热学和颜色性能也得到了改善,并显示出最高的雾度和最低的光透射率。这种简单有效的制备“核-壳”结构SiO2@TiO2纳米填料的方法具有很大的工业应用潜力。


Mechanical and tribological properties of CNTs coated aramid fiber-reinforced epoxy composites

Mayank Singh, Srihari Dodla, RK Gautam

doi:10.1016/j.compositesa.2024.108061

CNTs包覆芳纶纤维增强环氧复合材料的力学和摩擦学性能

This study primarily emphasizes the coating process of carbon nanotubes (CNTs) onto aramid fiber and investigates the subsequent effects of coating on the tribological, mechanical, and thermo-physical characteristics. CNTs and the aramid fibers are oxidized with the combination of sulphuric and nitric acids treatment. The chemical treatments resulted in an increased density of functional groups such as CO, COOH, and OH on the activated surface of the aramid fibers and CNTs. The tribological experiments involve four different normal loads (30 N, 40 N, 50 N, and 60 N), sliding frequencies (6 Hz, 8 Hz, 10 Hz, and 12 Hz), and temperatures (30°C, 40°C, 50°C, and 60°C). Each experiment runs for 20 minutes, using a fixed stroke length of 1.5 mm. The worn surfaces are analyzed using SEM images. It was observed that the CNTs-coated aramid fiber enhances the mechanical interlocking between the fibers and the matrix material, due to which the specific wear rate was reduced by 32.41%, and the tensile strength, modulus, hardness, and thermal conductivity were increased by 23.3%, 22.9%, 27.27%, and 36.56% respectively. The friction coefficient increases with the increase of the normal load, while it decreases with the rise in temperature or sliding frequency.

本研究主要研究了碳纳米管(CNTs)在芳纶纤维上的涂层过程,并研究了涂层对芳纶纤维摩擦学、力学和热物理特性的后续影响。采用硫酸和硝酸复合处理对CNTs和芳纶纤维进行氧化处理。化学处理增加了芳纶纤维和碳纳米管活化表面的CO、COOH和OH等官能团的密度。摩擦学实验包括4种不同的正常载荷(30n、40n、50n和60n)、滑动频率(6hz、8hz、10hz和12hz)和温度(30℃、40℃、50℃和60℃)。每次实验运行20分钟,固定行程长度为1.5 mm。利用扫描电镜对磨损表面进行了分析。结果表明,碳纳米管包覆芳纶纤维增强了纤维与基体材料之间的机械联锁作用,比磨损率降低了32.41%,拉伸强度、模量、硬度和导热系数分别提高了23.3%、22.9%、27.27%和36.56%。摩擦系数随法向载荷的增大而增大,随温度或滑动频率的升高而减小。


Composites Part B: Engineering

Injectable, stretchable, and conductance-stable fiber for myocardial infarction repair

Yimeng Li, Chaofu Li, Mengqi Shan, Leqian Wei, Lizhen Lan, Xiaoli Liu, Lamei Guo, Fujun Wang, Ze Zhang, Lu Wang, Li Shen, Jifu Mao

doi:10.1016/j.compositesb.2024.111242

 

可注射、可拉伸、电导稳定的纤维用于心肌梗死修复

Injecting electroactive biomaterials into infarcted myocardium to restore blocked electrical signal pathways is an effective way for repairing myocardial infarction. However, re-establishing stable and anisotropic conductive pathways during the constant contraction and relaxation of the heart remains a challenge. Herein, inspired by the myocardial fibers with striated surfaces, a super-elastic and conductance-stable polyurethane fiber with buckled polypyrrole coating (PU150 %@PPy) was designed. The bionic composite fiber exhibited excellent stretchability (>450 %), electrical stability under large strains (ΔR/R0 of only 0.04 at 100 % strain), and long-term durability (>1000000 cycles), enabling stable transmission of electrical signals in a beating heart. Specifically, the composite fibers could be injected into the infarct area in minimally invasive manner and aligned with the myocardial fibers to provide anisotropic conductive pathways. After injecting the PU@PPy fibers into the infarcted heart, the cardiac function was improved (33.19 % increase in fractional shortening and 38.80 % increase in ejection fraction) and the myocardial remodeling was decreased (40.30 % reduction in infarct size and 92.77 % increase in myocardial wall thickness) by re-establishing the electrical communication of the electrically separated cardiomyocytes in the infarct area as well as by providing mechanical support. The injectable, stretchable, and conductance-stable fiber offers a promising strategy for reconstructing infarcted myocardium.

向梗死的心肌注射电活性生物材料以恢复受阻的电信号通路是修复心肌梗死的有效方法。然而,在心脏不断收缩和松弛的过程中重建稳定且各向异性的传导通路仍是一项挑战。在此,受具有条纹表面的心肌纤维的启发,我们设计了一种具有降伏聚吡咯涂层(PU150 %@PPy)的超弹性和传导稳定的聚氨酯纤维。这种仿生复合纤维具有出色的伸展性(>450 %)、大应变下的电稳定性(100 % 应变下的ΔR/R0 仅为 0.04)和长期耐久性(>1 亿次循环),可在跳动的心脏中稳定传输电信号。具体来说,复合纤维可通过微创方式注入梗死区,并与心肌纤维排列在一起,提供各向异性的导电路径。将 PU@PPy 纤维注入梗塞心脏后,通过重建梗塞区电性分离的心肌细胞之间的电交流以及提供机械支持,心脏功能得到改善(缩短率增加 33.19%,射血分数增加 38.80%),心肌重塑程度降低(梗塞面积缩小 40.30%,心肌壁厚度增加 92.77%)。这种可注射、可拉伸、电导稳定的纤维为重建梗死心肌提供了一种前景广阔的策略。


Process characteristics, damage mechanisms and challenges in machining of fibre reinforced thermoplastic polymer (FRTP) composites: A review

Jia Ge, Giuseppe Catalanotti, Brian G. Falzon, Colm Higgins, Caroline McClory, Jean-Aubin Thiebot, Li Zhang, Miaomiao He, Yan Jin, Dan Sun

doi:10.1016/j.compositesb.2024.111247

 

纤维增强热塑性聚合物(FRTP)复合材料加工的工艺特点、损伤机理及面临的挑战

Fibre reinforced thermoplastic polymer (FRTP) composites have been used for a wide range of engineering applications (e.g. in transport, construction, energy, etc) due to their excellent mechanical properties and ease of repair and recycling. In recent years, FRTP is increasingly deployed as an alternative to conventional thermoset carbon fibre reinforced epoxy (CF/epoxy) composites, for the purpose of reducing the carbon footprint and contributing to a sustainable manufacturing agenda. Machining of FRTP remains an indispensable process to achieve rapid parts assembly whilst meeting stringent geometric tolerances. However, due to the heterogeneous structure and high thermal sensitivity of FRTP, a range of machining-induced damages (such as matrix smearing, thermal degradation, delamination, burr and surface cavity) often occur, leading to concerns on machined parts quality and reliability. To date, composite machining studies have been mostly focused on conventional thermoset CF/epoxy and there is a lack of an up-to-date, in-depth review of the latest advancement concerning the machining of thermoplastic FRTP. This paper provides a state-of-the-art overview on the recent developments in FRTP machining over the past decade, with a particular emphasis on machining characteristics, damage mechanisms as well as the challenges facing such manufacturing process. The purpose is to present the composite manufacturing community with a timely update, which may guide and inspire further research and development for future FRTP manufacturing.

纤维增强热塑性聚合物(FRTP)复合材料由于其优异的机械性能和易于修复和回收,已广泛用于工程应用(例如在运输,建筑,能源等)。近年来,FRTP越来越多地作为传统热固性碳纤维增强环氧树脂(CF/环氧)复合材料的替代品,以减少碳足迹并促进可持续制造议程。为了在满足严格的几何公差的同时实现零件的快速装配,FRTP的加工仍然是必不可少的过程。然而,由于FRTP的非均匀结构和高热敏性,经常会发生一系列加工引起的损伤(如基体涂布、热退化、分层、毛刺和表面空腔),导致对加工零件质量和可靠性的担忧。到目前为止,复合材料的加工研究主要集中在传统的热固性CF/环氧树脂上,缺乏对热塑性FRTP加工最新进展的深入研究。本文概述了近十年来FRTP加工的最新发展,特别强调了加工特性、损伤机制以及这种制造过程面临的挑战。目的是向复合材料制造界提供及时的更新,这可能会指导和启发未来FRTP制造的进一步研究和开发。


Osteoimmunomodulatory bioinks for 3D bioprinting achieve complete regeneration of critical-sized bone defects

Xingge Yu, Shengjie Jiang, Dejian Li, Steve GF. Shen, Xudong Wang, Kaili Lin

doi:10.1016/j.compositesb.2024.111256

 

用于3D生物打印的骨免疫调节生物墨水实现了临界尺寸骨缺损的完全再生

Regeneration the critical-sized bone defects remains a great challenge to clinical therapy due to the inflammatory microenvironment and lack of stem cells in the region of the bone defects. 3D bioprinted scaffolds based on bioactive ink and loaded active cells can promote the inflammatory microenvironment and cell viability, thereby enhancing bone regeneration. In this study, 10 % Gelatin-methacryloyl (GelMA)/5%Sr substituted xonotlite (Sr-CSH) nanocomposite hydrogel was developed as a bioink to encapsulate bone marrow mesenchymal stem cells (BMSCs), and then constructed a biomimetic bone tissue by 3D bioprinting. The incorporation of Sr-CSH nanowires enhanced the printing accuracy and mechanical property of GelMA, and enhanced the osteogenic differentiation of BMSCs. In addition, Sr-CSH induced macrophage M2 polarization, which modulated the inflammatory microenvironment and further promoted osteogenic differentiation of BMSCs. In rat critical-sized calvarial defects model, 3D bioprinted scaffolds based on GelMA-Sr-CSH bioinks laden with BMSCs achieve complete bone repair. In summary, this study developed an osteoimmunomodulatory bioink, and 3D bioprinted scaffolds laden with stem cells may be an effective method for achieving complete regeneration of critical-sized bone defects.

由于骨缺损部位的炎症微环境和缺乏干细胞,对临界尺寸骨缺损的再生仍然是临床治疗的一大挑战。基于生物活性墨水和负载活性细胞的生物3D打印支架可以促进炎症微环境和细胞活力,从而增强骨再生。本研究以10 %明胶-甲基丙烯酰(GelMA)/5%Sr取代硬石(Sr-CSH)纳米复合水凝胶作为生物连接材料包封骨髓间充质干细胞(BMSCs),并通过生物3D打印构建仿生骨组织。Sr-CSH纳米线的掺入提高了GelMA的打印精度和力学性能,促进了BMSCs的成骨分化。此外,Sr-CSH诱导巨噬细胞M2极化,从而调节炎症微环境,进一步促进骨髓间充质干细胞成骨分化。在大鼠颅骨缺损模型中,基于装载骨髓间充质干细胞的GelMA-Sr-CSH生物墨水的3D生物打印支架实现了完整的骨修复。总之,本研究开发了一种骨免疫调节生物链接,装载干细胞的生物3D打印支架可能是实现临界尺寸骨缺损完全再生的有效方法。


A hydrogel derived from skin secretion of Andrias davidianus to facilitate bone regeneration

Qi Zhang, Xing Feng, Siyu Peng, Lan Li, Yangfan Xiang, Tengchao Feng, Ximu Zhang, Jinlin Song

doi:10.1016/j.compositesb.2024.111261

一种从大鲵皮肤分泌物中提取的水凝胶,促进骨再生

Bone regeneration relies heavily on balancing osteogenesis and osteoclastogenesis. Meeting the challenge of creating bone repair scaffolds with dual functionalities has long been elusive in bone tissue engineering. This study addresses these challenges through the utilization of a unique hydrogel that capitalizes on the dynamics of disulfide bonding to convert the skin secretion of Andrias davidianus (SSAD) into hydrolysate. This hydrolysate serves as the foundation for the construction of a novel SSAD protein hydrogel for bone regeneration, achieved through a photo-redox reaction under visible light crosslinking. The innovative SSAD protein hydrogel not only exhibits exceptional biocompatibility but also significantly enhances bone mineralization and angiogenesis in vitro. RNA sequencing delves into the underlying mechanisms governing the regulation of osteogenesis and osteoclastogenesis by the hydrogel. In vivo experiments conclusively demonstrate the potential of the SSAD protein hydrogel. It expedites vascularization within the defect area and synergistically facilitates the repair of bone defects. Furthermore, the SSAD hydrogel exhibits notable antimicrobial properties, effectively reducing the risk of implant-related infections in vivo. In summary, this research introduces a valuable and promising method for fabricating protein biomaterials that contribute to bone repair by promoting both bone and blood vessel growth while simultaneously inhibiting osteoclast formation.

骨再生在很大程度上依赖于骨生成和破骨细胞生成的平衡。制造具有双重功能的骨修复支架在骨组织工程中一直是一个难以实现的挑战。本研究通过利用一种独特的水凝胶来解决这些挑战,这种水凝胶利用二硫键的动力学将大鲵(SSAD)的皮肤分泌物转化为水解产物。该水解产物是构建用于骨再生的新型SSAD蛋白水凝胶的基础,通过在可见光交联下的光氧化还原反应实现。创新的SSAD蛋白水凝胶不仅具有优异的生物相容性,而且在体外显著增强骨矿化和血管生成。RNA测序深入研究了水凝胶调控成骨和破骨细胞发生的潜在机制。体内实验最终证明了SSAD蛋白水凝胶的潜力。它加速缺损区域内的血管化,并协同促进骨缺损的修复。此外,SSAD水凝胶具有显著的抗菌性能,可有效降低体内植入物相关感染的风险。总之,本研究介绍了一种有价值和有前途的方法来制造蛋白质生物材料,通过促进骨骼和血管的生长,同时抑制破骨细胞的形成,有助于骨修复。


3D printed sequence-controlled copolyimides with high thermal and mechanical performance

Xinyu Du, Yi Liu, Song Mo, Lei Zhai, Minhui He, Lin Fan, Yuliang Wang, Wei Zhao, Gong Wang

doi:10.1016/j.compositesb.2024.111262

 

具有高热性能和机械性能的3D打印序列控制共聚物

Inadequate heat resistance and mechanical property limited the application of 3D printed polymer parts in aerospace industry. To address this restriction, a kind of sequence-controlled copolyimides with both amorphous segment and crystalline segment, suitable for fused deposition modeling 3D printing technique were designed and synthesized. The effect of content and distribution of crystalline segment on melt fluidity and crystallization behavior was disclosed. It was found that copolyimide with crystalline segment only distributed in the end of backbone exhibited good melt fluidity and slow crystallization rate. Microstructure change of the corresponding copolyimide during 3D printing and thermal annealing was revealed. Due to slow crystallization rate of copolyimide, no crystals formed during 3D printing. Thus, the diffusion and entanglement of polymer chain at interface were guaranteed. Thermal annealing at 350 °C facilitated diffusion and arrangement of polymer chain, leading to the enhancement of interfacial bonding and crystallization of copolyimide at interface and in filament. Therefore, the printed copolyimide specimens exhibited high heat resistance, high mechanical property and excellent interfacial bonding performance. The tensile strength of specimens printed in XY plane with 0° infill direction (XY-0), XY plane with 90° infill direction (XY-90) and XZ plane with 90° infill direction (XZ-90) were 110MPa, 96MPa and 57MPa, respectively. The tensile strength of XY-0 printed specimen at 200 °C was 186 % higher than that of XY-0 printed amorphous polyimide specimen, reaching 40 MPa. This study expanded the kinds of polymeric materials suitable for fused deposition modeling, and provided the possibility of printing high performance engineering parts.

3D打印聚合物部件的耐热性和力学性能不足限制了其在航空航天工业中的应用。针对这一限制,设计并合成了一种适合于熔融沉积建模3D打印技术的非晶段和结晶段序列控制的共聚物。揭示了晶段含量和分布对熔体流动性和结晶行为的影响。研究发现,结晶段仅分布于骨架末端的共聚物具有良好的熔体流动性和较慢的结晶速率。揭示了相应共聚物在3D打印和热退火过程中的微观结构变化。由于共聚物的结晶速率较慢,在3D打印过程中不会形成结晶。从而保证了聚合物链在界面处的扩散和缠结。350℃的热处理有利于聚合物链的扩散和排列,界面键合增强,共聚亚胺在界面和细丝处结晶。因此,打印的共聚物亚胺样品具有高的耐热性、高的力学性能和优异的界面结合性能。在0°填充方向的XY平面(XY-0)、90°填充方向的XY平面(XY-90)和90°填充方向的XZ平面(XZ-90)打印试件的抗拉强度分别为110MPa、96MPa和57MPa。XY-0印刷样品在200 ℃下的抗拉强度比XY-0印刷非晶聚酰亚胺样品高186 %,达到40 MPa。该研究扩大了适合熔融沉积建模的聚合物材料种类,并为打印高性能工程部件提供了可能。


Boron carbide based composites densified via Ti3SiC2 boronizing with excellent mechanical properties and amorphization tolerance

Zhengang Xiong, Ji Zou, Jingjing Liu, Wei Ji, Weimin Wang, Zhengyi Fu

doi:10.1016/j.compositesb.2024.111264

碳化硼基复合材料经Ti3SiC2渗硼致密化,具有优异的力学性能和非晶化容忍度

Consolidated boron carbide (B4C) composites are extremely hard but have been shown to undergo stress-induced amorphization when subjected to high velocity impact. This localized amorphization has been related to the sudden loss of their strength and poor ballistic protection. In this work, dense B4C based composites were spark plasma sintered through in-situ reactions involving with Ti3SiC2 and boron. Hierarchical structures composed of TiB2–SiC–Si reinforcement and B4C matrix were finally built and the degree of amorphization was markedly reduced as the increment of boron amounts. As-generated composites with tough and hard reinforcement possess enhanced amorphization resistance without compromising their mechanical properties. Due to the co-doping of Si and B in boron carbide, the amorphization degree yields a reduction of up to 73 %. The dominant amorphous tolerance is associated with the chain retention and atomic-level local lattice distortion in boron carbide. Therefore, Ti3SiC2 boronizing route may present itself a promising strategy to design boron carbide based composites with better ballistic performance.

固结碳化硼(B4C)复合材料非常坚硬,但在高速冲击下会发生应力诱导的非晶化。这种局部非晶化与它们突然失去强度和较差的弹道保护有关。在本工作中,通过与Ti3SiC2和硼的原位反应,制备了致密的B4C基复合材料。最终形成TiB2-SiC-Si增强体和B4C基体组成的分层结构,且随着硼用量的增加,非晶化程度明显降低。在不影响其力学性能的情况下,具有韧性和硬质增强的复合材料具有增强的抗非晶化能力。由于Si和B在碳化硼中共掺杂,非晶化程度降低了73% %。在碳化硼中,主要的非晶公差与链保留和原子水平的局部晶格畸变有关。因此,Ti3SiC2渗硼路线可能是设计具有更好弹道性能的碳化硼基复合材料的一种有前途的策略。


Composite metamaterial antenna with super mechanical and electromagnetic performances integrated by three-dimensional weaving technique

Wuzhou Li, kun Zhang, Rui Pei, Fujun Xu

doi:10.1016/j.compositesb.2024.111265

采用三维编织技术合成具有超强机械性能和电磁性能的复合材料天线

The integration of structure and function was crucial for the application of microstrip antennas. Layered microstrip antennas were prone to delamination, which severely limits their performance stability. The textile conformal microstrip antenna with integrated structure design prevented the layered failure and greatly improved the damage resistance of the antenna. However, textiles had an inherent deficiency in suppressing surface waves due to their discontinuous mesh structure, critically deteriorating the radiation performance of microstrip antennas. Electromagnetic metamaterial with a specific pattern resonated in the excitation of electromagnetic waves to form a forbidden bandgap, which was expected to suppress surface wave radiation of microstrip antennas. In this study, a textile-based microstrip antenna integrated with electromagnetic metamaterials (MA-EBG) was proposed by embedding conductive copper wires in three-dimensional (3D) spacer fabric to form an integrated structure. Due to the function of the forbidden bandgap in metamaterial structure, the surface wave radiation was suppressed and the gain of antenna was increased from 5.1 dB to 9.6 dB. Owing to the tight physical binding, MA-EBG retained its structural integrity with proper electromagnetic performance under the impact of 24 J. The application of electromagnetic metamaterials elevated the gain of textile-based microstrip antennas, which provided a new method for the design of high-gain textile-based microstrip antennas with excellent mechanical properties.

结构与功能的整合是微带天线应用的关键。层状微带天线容易发生分层,严重限制了其性能稳定性。采用一体化结构设计的纺织共形微带天线防止了分层失效,大大提高了天线的抗损伤性。然而,纺织品由于其不连续的网格结构,在抑制表面波方面存在固有的缺陷,严重影响了微带天线的辐射性能。具有特定模式的电磁超材料在电磁波激发下共振形成禁带隙,有望抑制微带天线的表面波辐射。在本研究中,提出了一种基于纺织品的电磁超材料集成微带天线(MA-EBG),该天线通过在三维(3D)间隔织物中嵌入导电铜线形成集成结构。由于超材料结构中禁带隙的作用,表面波辐射受到抑制,天线增益由5.1 dB提高到9.6 dB。由于紧密的物理结合,MA-EBG在24 J的影响下保持了结构的完整性和良好的电磁性能。电磁超材料的应用提高了纺织微带天线的增益,为设计具有优异力学性能的高增益纺织微带天线提供了新方法。


One-step construction of three-dimensional disordered graphene-like pyrolytic carbon composites by oxygen controllable chemical vapor deposition

Caixiang Xiao, Fei Zhao, Yameng Jiao, Yuanxiao Zhao, Qiang Song, Hejun Li

doi:10.1016/j.compositesb.2024.111266

 

氧可控化学气相沉积法一步构建三维无序类石墨烯热解碳复合材料

Multi-scale reinforcement strategies have been widely integrated in the preparation of high-performance composites for high strength and functionality, but it is challenging to achieve the microstructurally adjustable and the feasible design of modulus matching between the matrix and the nano-reinforcements. Herein, we integrated the preparation of graphene nano-reinforcements with pyrolytic carbon matrix by a one-step oxygen controllable chemical vapor deposition (OCCVD) process and designed a multi-step gradient of the modulus carbon composite. Furthermore, the microstructure morphology and the deep molecular insights under different oxygen contents were obtained by simulating the OCCVD process based on reactive molecular dynamics. Additionally, the modulus and fracture strength of different carbon structures were acquired by corresponding mechanical simulations. On this basis, the experimentally designed and prepared multiscale carbon/carbon composites simultaneously exhibited excellent flexural mechanical properties and matrix deformation capacity compared with the conventional carbon/carbon composites. The interpenetrating structural features of the prepared composites promote a high level of interfacial shear resistance, resulting in significantly enhanced load transfer strengthening as well as crack-bridging toughening. Our method provides new insights into the chemical vapor deposition process and a new way of thinking about the fabrication of high specific strength composites with great simplicity and versatility.

多尺度增强策略已广泛应用于高性能复合材料的高强度和功能性制备中,但如何实现基体与纳米增强材料之间的微观结构可调和模量匹配的可行设计是一个挑战。本文采用一步氧可控化学气相沉积(OCCVD)工艺制备了石墨烯纳米增强材料和热解碳基体,并设计了多步梯度模碳复合材料。此外,通过反应分子动力学模拟OCCVD过程,获得了不同氧含量下的微观结构形态和深层分子特征。通过力学模拟得到了不同碳结构的模量和断裂强度。在此基础上,实验设计和制备的多尺度碳/碳复合材料与常规碳/碳复合材料相比,同时具有优异的弯曲力学性能和基体变形能力。所制备的复合材料的互穿结构特征提高了界面抗剪切能力,从而显著增强了载荷传递强化和裂缝桥接增韧。我们的方法为化学气相沉积工艺提供了新的见解,并为制造具有简单性和通用性的高比强度复合材料提供了新的思路。


Composites Science and Technology

Fracture analysis of chopped carbon fiber sheet molding compound composite under tensile loading via in-situ μXCT

Ziwei Jiao, Kaifeng Wang, Jingjing Li, Zhengyu Ma

doi:10.1016/j.compscitech.2024.110476

 

剪切碳纤维板材成型复合材料在拉伸载荷作用下的断裂分析

This paper investigated the crack initiation in a chopped carbon fiber sheet molding compound (SMC) composite under different tensile loads by integrating synchrotron micro-X-ray computed tomography (μXCT) and micromechanics analysis. It was found that the varied distribution of fiber chips in the SMC composite led to distinct fracture propagation behaviors. With the loading increasing, the crack primarily occurred within the fiber chips, and the delamination exited when the crack propagated along the interface between adjacent layers. To understand the location and sequence of crack initiation in SMC composites, the sample were divided into identical cubes. After tracking the microstructure of each cube, the corresponding interfacial debonding strength as well as Young's modulus were predicted. Predictive modeling of crack initiation characteristics was conducted assuming homogeneous material deformation under small strain. The predicted outcomes closely matched with the experimental findings.

采用同步微x射线计算机断层扫描(μXCT)和细观力学分析相结合的方法,研究了短切碳纤维薄板成型复合材料(SMC)在不同拉伸载荷作用下的裂纹萌生过程。研究发现,SMC复合材料中纤维切屑分布的不同导致了不同的断裂扩展行为。随着载荷的增加,裂纹主要发生在纤维片内部,裂纹沿相邻层间界面扩展时产生分层;为了了解SMC复合材料裂纹起裂的位置和顺序,将样品分成相同的立方体。在对每个立方体的微观结构进行跟踪后,预测了相应的界面剥离强度和杨氏模量。假设材料在小应变下均质变形,对裂纹起裂特性进行了预测建模。预测结果与实验结果非常吻合。


Trilayer structured ceramic/polymer nanocomposites with superior breakdown strength and discharged energy density

Yan Guo, Weichen Zhao, Da Li, Yang Liu, Lixia Pang, Zhongqi Shi, Wenfeng Liu, Jinzhan Su, Guohua Chen, Di Zhou

doi:10.1016/j.compscitech.2024.110477

 

具有优异击穿强度和放电能量密度的三层结构陶瓷/聚合物纳米复合材料

The excellent dielectric constant (εr) and breakdown strength (Eb) of dielectric nanocomposites are the necessary conditions for their excellent energy storage properties (ESPs) in microelectronics and power systems. In recent years, inorganic nanofillers and multilayer structure design have provided an efficient way to improve the ESPs of dielectric composites. Herein, we selected 0.8Bi0.5(Na0.82K0.18)0.5TiO3-0.2Sr(Sc0.5Nb0.5)O3 cecamic nanoparticles (BNKT-SSN NPs) with high εr and low loss as nanofillers, and prepare novel trilayer structured BNKT-SSN/P(VDF-HFP) nanocomposites to improve the εr and Eb. The investigated phenomena demonstrate that due to the contribution of BNKT-SSN NPs incorporation and interfacial polarization between neighboring layers, the εr and Eb of the trilayer structured BNKT-SSN/P(VDF-HFP) nanocomposites are enhanced while the dielectric loss (tanδ) and leakage current density are suppressed. It is worth noting that the Eb is measured up to 650 MV m−1 when the intermediate layer fillers BNKT-SSN NPs of the trilayer structured nanocomposite is 0.75 vol%, and the discharged energy density (Ud) and energy efficiency (η) are 25.79 J cm−3 and 70.07 %, respectively. In this work, it's demonstrates that the incorporation of inorganic ceramic fillers and the trilayer structured design provide a feasible approach of improving the ESPs of dielectric nanocomposites.

介电纳米复合材料优异的介电常数(εr)和击穿强度(Eb)是其在微电子和电力系统中实现优异储能性能(ESP)的必要条件。近年来,无机纳米填料和多层结构设计为提高电介质复合材料的ESP提供了有效途径。本文选择具有高εr和低损耗的0.8Bi0.5(Na0.82K0.18)0.5TiO3-0.2Sr(Sc0.5Nb0.5)O3陶瓷纳米粒子(BNKT-SSN NPs)作为纳米填料,制备了新型三层结构的BNKT-SSN/P(VDF-HFP)纳米复合材料,以改善εr和Eb。研究结果表明,由于 BNKT-SSN NPs 的加入和相邻层间界面极化的作用,三层结构 BNKT-SSN/P(VDF-HFP) 纳米复合材料的 εr 和 Eb 得到了提高,同时介电损耗(tanδ)和漏电流密度得到了抑制。值得注意的是,当三层结构纳米复合材料的中间层填料 BNKT-SSN NPs 为 0.75 vol% 时,Eb 测量值高达 650 MV m-1,放电能量密度(Ud)和能量效率(η)分别为 25.79 J cm-3 和 70.07 %。这项研究表明,无机陶瓷填料的加入和三层结构设计为提高电介质纳米复合材料的储能性能提供了一种可行的方法。



来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveSystemInspire断裂复合材料化学电路通用航空航天建筑电力ECAD裂纹理论材料分子动力学
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【新文速递】2024年1月20日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 1 篇,Journal of the Mechanics and Physics of Solids 1 篇,Thin-Walled Structures 5 篇International Journal of Solids and StructuresNon-contact electromagnetic controlled metamaterial beams for low-frequency vibration suppressionYu Sun, Haokai Zheng, Qiang Han, Chunlei Lidoi:10.1016/j.ijsolstr.2024.112667 用于低频振动抑制的非接触式电磁控制超材料梁To address the challenge of suppressing extremely-low frequency vibration and noise in precision instruments and equipment, a novel non-contact metamaterial beams is proposed in this paper. The resonators of the metamaterial beams integrate negative stiffness mechanism and electromagnetic damping tuning system. Based on the magnetic dipole theory and the electromagnetic induction law, the mechanical model of magnetic resonator is established. The band structure and transmission spectrum of the metamaterial beams are obtained by transfer matrix method. Besides, the results of numerical simulations are used to verify the accuracy of theoretical results. The result shows that the negative stiffness can be controlled by nonlinear magnetic force among the magnets. Based on this mechanism, the bandgap frequency can be reduced to a minimum of 50Hz. Then, the method of combining electromagnetic damping and negative impedance circuit is proposed to form a tuning system which can reduce the initial frequency of the bandgap to 4Hz. Interestingly, the proposed bandgap control mechanism achieves the extremely-low bandgap while broadens the bandwith relatively, which overcomes the deficiency of traditional quasi-zero-stiffness metamaterials that reduce the bandgap frequency while causing the bandwidth to narrow. This study is expected to provide valuable ideas for the application of metamaterials in the field of low-frequency vibration and noise reduction.为解决精密仪器设备中极低频振动和噪声的抑制问题,提出了一种新型非接触式超材料梁。超材料梁谐振腔集成了负刚度机构和电磁阻尼调谐系统。基于磁偶极子理论和电磁感应定律,建立了磁谐振器的力学模型。利用传递矩阵法得到了超材料光束的能带结构和透射谱。此外,用数值模拟结果验证了理论结果的准确性。结果表明,磁体间的非线性磁力可以控制负刚度。基于这种机制,带隙频率可以降低到至少50Hz。然后,提出了电磁阻尼与负阻抗电路相结合的方法,形成了一个可将带隙初始频率降至4Hz的调谐系统。有趣的是,所提出的带隙控制机制实现了极低的带隙,同时相对拓宽了带宽,克服了传统准零刚度超材料在降低带隙频率的同时导致带宽变窄的缺点。该研究有望为超材料在低频振动降噪领域的应用提供有价值的思路。Journal of the Mechanics and Physics of SolidsModeling storage particle delamination and electrolyte cracking in cathodes of solid state batteriesTao Zhang, Marc Kamlah, Robert M. McMeekingdoi:10.1016/j.jmps.2024.105551固态电池阴极中存储颗粒分层和电解液开裂的模拟Interface delamination between storage particles and solid electrolytes contributes to greater impedance for Li transfer and capacity loss in solid-state batteries. Electrolyte cracking would cause degradation of the ionic or electronic conductivity of electrolytes. The occurrence of interface delamination and electrolyte cracking is commonly ascribed to mechanical stress, which evolves from inhomogeneous shrinkage and swelling of storage particles confined by the surrounding solid electrolytes when lithium is extracted or inserted. Here, a coupled model of Li diffusion, ionic conduction, interfacial reaction, mechanical stress and a phase field fracture approach is applied to investigate defect-initiated interface delamination and how cracks nucleate in electrolytes in a full 3D dynamical description for the first time. We find that unstable interface delamination is a very likely event during extraction. On the other hand, homogeneous delamination where the whole interface delaminates simultaneously, can happen for smaller interfacial defects with larger particle sizes and higher applied current densities. Larger interfacial defects delay the onset of delamination due to damage dependent interfacial reaction. More particle storage capacity can be utilized for smaller particle sizes and smaller interfacial defects prior to delamination. We further demonstrate electrolyte cracking can happen quite readily, and the electrolyte can break into several parts in only one insertion half cycle and even the appearance of full delamination.在固态电池中,存储颗粒和固体电解质之间的界面分层导致锂离子转移阻抗增大和容量损失增大。电解液的开裂会导致电解液的离子或电子导电性下降。界面分层和电解质开裂的发生通常归因于机械应力,这是锂提取或插入时由周围固体电解质限制的存储颗粒的不均匀收缩和膨胀演变而来的。本文首次采用Li扩散、离子传导、界面反应、机械应力和相场断裂的耦合模型,对缺陷引发的界面分层以及裂纹如何在电解质中成核进行了完整的三维动力学描述。我们发现不稳定的界面分层是萃取过程中很可能发生的事件。另一方面,对于较小的界面缺陷,较大的颗粒尺寸和较高的施加电流密度,可以发生整个界面同时分层的均匀分层。由于损伤相关的界面反应,较大的界面缺陷延迟了分层的发生。在分层之前,更小的颗粒尺寸和更小的界面缺陷可以利用更多的颗粒存储容量。我们进一步证明了电解质的开裂是很容易发生的,电解质可以在一个插入半周期内分解成几个部分,甚至出现完全分层。Thin-Walled StructuresComparison of two progressive damage models for predicting low-velocity impact behavior of woven compositesYogesh Kumar, Mohammad Rezasefat, Sandro C. Amico, Andrea Manes, Patricia I. Dolez, James D. Hogandoi:10.1016/j.tws.2024.111611两种预测编织复合材料低速冲击行为的渐进损伤模型的比较This research focuses on comparing the two progressive damage models available in the explicit nonlinear finite element software LS-Dyna. To explore the prediction capabilities in terms of mechanical response and dominating failure modes in S2 glass woven composites, low velocity impact response at four different energies ranging from 27.9 J to 109.7 J were considered in this study. A macro-homogeneous solid element formulated finite element model was simulated to understand the response and failure mechanics in the laminate under low-velocity impact. The material modeling was carried out utilizing the MAT 55 and MAT 162 material models. An effort has been made for robust calibration of the various physical and non-physical parameters in both material cards for accurate predictions. The prediction capabilities of the models were then examined by comparing them against the experimental results, which fall within the deviation of ∼ 11%. The results show that MAT 162 yields a better resemblance with the damage morphology patterns and the delamination for the accounted impact zone, due to inclusion of strain-rate effect. Overall, this paper provides insight into the limitations and advantages of both material models, which establishes the route for the selection of the appropriate material model for simulating impact behavior in woven composites.本文主要对LS-Dyna显式非线性有限元软件中现有的两种渐进损伤模型进行了比较。为了探索S2玻璃编织复合材料力学响应和主要破坏模式的预测能力,本研究考虑了27.9 ~ 109.7 J四种不同能量下的低速冲击响应。为了解层合板在低速冲击下的响应和破坏机理,建立了宏观均质实体有限元模型。利用MAT 55和MAT 162材料模型进行材料建模。为了准确预测,已经努力对两种材料卡中的各种物理和非物理参数进行稳健校准。然后通过将模型与实验结果进行比较来检验模型的预测能力,实验结果的偏差在~ 11%之内。结果表明,由于包含应变率效应,MAT 162与计算的冲击区损伤形态和分层具有更好的相似性。总体而言,本文深入分析了两种材料模型的局限性和优势,为选择合适的材料模型来模拟机织复合材料的冲击行为奠定了基础。Surface effects on wave propagation in piezoelectric-piezomagnetic loosely bonded bilayer system using nonlocal theory of elasticitySudarshan Dhua, Subrata Mondal, Arpita Majidoi:10.1016/j.tws.2024.111612基于非局部弹性理论的压电-压电松散键合双层体系中波传播的表面效应This study investigates nonlocal and surface effects on the dispersion behaviors of Shear horizontal (SH) waves in piezoelectric(PE)- piezomagnetic(PM) bilayer systems. The interface between these two layers is imperfectly bonded. The general governing equations are derived from the nonlocal magnetoelectroelastic (MEE) theory by adding an inherent length. The G-M model and generalized Younge–Laplace equations have been used to incorporate surface effects into the boundary conditions of the bilayer systems. The closed-form dispersion equation is obtained analytically for electrically open and magnetically short conditions. Numerical solutions are utilized to investigate the effects of nonlocal scale parameters and surface parameters on SH surface wave propagation. Contrary to the results of classical theory, the coupling effects of nonlocal small-scale and surface piezoelectricity are more significant than individual effects. Also, it has been observed that the imperfectness parameter across the interface and the thickness ratio of the bilayer significantly affect the phase velocity. Moreover, 2D and 3D plots of the mode shapes of field variables for the propagation of SH waves are presented graphically. These results are validated by conducting analyses excluding nonlocal effects. This allows us to isolate the specific impact of surface effects in the piezoelectric-piezomagnetic bilayer system, drawing connections to existing results and enhancing the robustness of our findings. This study provides valuable insights into complex wave dynamics, helping to optimize the performance and functionality of such smart composites in various engineering applications.本文研究了压电(PE)-压磁(PM)双层体系中剪切水平波(SH)色散行为的非局域和表面效应。这两层之间的界面是不完美结合的。一般控制方程由非局部磁电弹性(MEE)理论导出,并加入固有长度。利用G-M模型和广义young - laplace方程将表面效应纳入双层系统的边界条件。得到了电开和磁短条件下的闭式色散方程。利用数值解研究了非局部尺度参数和表面参数对SH表面波传播的影响。与经典理论的结果相反,非局部小尺度和表面压电的耦合效应比个体效应更显著。此外,还观察到界面上的缺陷参数和双层膜的厚度比对相速度有显著影响。此外,还给出了SH波传播场变量模态振型的二维和三维图形。通过进行排除非局部效应的分析,验证了这些结果。这使我们能够分离出压电-压电双分子层系统中表面效应的具体影响,将其与现有结果联系起来,并增强我们发现的稳健性。这项研究为复杂的波动动力学提供了有价值的见解,有助于优化这种智能复合材料在各种工程应用中的性能和功能。GLARE deformation in low-restraint state: tensile and bending behaviorYao Wang, Xiaokai Ye, Chao Yang, Junzhe Wei, Sifa Zheng, Libin Zhao, Ning Hudoi:10.1016/j.tws.2024.111613低约束状态下的眩光变形:拉伸和弯曲行为Fiber metal laminates (FMLs) possess a better weight reduction effect than traditional metal materials due to the coupling properties of heterogeneous materials, showing promise in the areas of aviation and aerospace. At present, the research on FMLs mainly focuses on the deformation properties after curing while the mechanical properties in the low-restraint state, i.e. the laminates are temporarily not cured and are formed under lower constraint stresses, are not studied in detail. Herein, the low-restraint GLARE is taken as a research object and its deformation characteristics and failure mode are studied using uniaxial tensile, bending experiments and numerical simulation in this paper. Moreover, the influence of key parameters, such as temperature, laminate structure and span length, is investigated, as well as the tensile and bending deformation behavior of GLARE in a low-restraint state is obtained. In addition, based on experimental observations, it is found that the low-restraint GLARE produces the phenomenon of interlayer slip, and the interlaminar residual stress is much smaller than the cured laminate, whereas the deformation limit and performance are improved. This paper provides theoretical bases for the in-depth analysis of deformation properties and forming laws of low-restraint GLARE, guiding further applications of laminates.由于非均质材料的耦合特性,金属纤维层压板具有比传统金属材料更好的减重效果,在航空航天领域具有广阔的应用前景。目前,对层合材料的研究主要集中在固化后的变形性能上,而对层合材料在低约束状态下,即暂时不固化,在较低约束应力下形成的力学性能研究较少。本文以低约束眩光为研究对象,通过单轴拉伸、弯曲试验和数值模拟对其变形特性和破坏模式进行了研究。此外,研究了温度、层合结构、跨长等关键参数对眩光的影响,得到了眩光在低约束状态下的拉伸和弯曲变形行为。此外,基于实验观察发现,低约束眩光会产生层间滑移现象,层间残余应力远小于固化层板,但变形极限和性能均有所提高。本文为深入分析低约束眩光的变形特性和形成规律提供了理论依据,指导了层合板的进一步应用。Dual-functional perforated metamaterial plate for amplified energy harvesting of both acoustic and flexural wavesTian Deng, Luke Zhao, Feng Jindoi:10.1016/j.tws.2024.111615双功能穿孔超材料板,用于放大声波和弯曲波的能量收集Metamaterials with defect states are commonly utilized in energy harvesting from acoustic and elastic waves due to their remarkable ability to localize waves. In this study, a novel piezoelectric energy harvester based on a perforated double-pillars metamaterial plate with a point defect, which offers the advantage of efficiently harvesting both ambient acoustic and flexural wave energy, is proposed. The proposed structure incorporates a locally resonant mechanism that enhances the concentration of vibration energy at the defect band frequency. Then, the amplified wave energy is efficiently converted into electrical energy by attaching a piezoelectric patch at the defect position. To initiate this investigation, the differential quadrature method is employed to theoretically estimate the boundary frequencies of the first band gap. Subsequently, this study investigates how holes size, electrical boundary conditions, and electrical circuit connections affect the energy harvesting of both acoustic and flexural waves. Correspondingly, the mechanisms behind their effects are thoroughly explained. Numerical results demonstrate that the wave energy localization performance can be remarkably amplified with an increasing holes radius, and the harvesters with the 1mm holes radius generate voltages that are approximately 2.12 and 1.44 times higher than those with the 0mm holes radius from acoustic and flexural waves, respectively. Furthermore, variations in the defect band frequency and corresponding wave localization behavior depend on the specific electrical boundary conditions and circuit connection approaches, ultimately leading to distinct results in the output electrical energy. These findings present valuable insights and guidelines for the development of high-performance electronic applications in the context of acoustic and elastic wave energy harvesting.具有缺陷态的超材料由于其出色的波局部化能力而被广泛应用于声波和弹性波的能量收集中。本文提出了一种基于带点缺陷的多孔双柱超材料板的新型压电能量收集器,该收集器具有有效收集环境声波和弯曲波能量的优点。所提出的结构包含一个局部共振机制,增强了振动能量在缺陷频带频率上的集中。然后,通过在缺陷位置粘贴压电片,将放大后的波能有效地转化为电能。为了开展这项研究,采用微分正交法从理论上估计了第一带隙的边界频率。随后,本研究探讨了孔大小、电边界条件和电路连接如何影响声波和弯曲波的能量收集。相应地,对其作用背后的机制也作了详尽的解释。数值结果表明,随着孔半径的增大,波能局域化性能显著增强,孔半径为1mm的收集器产生的声波电压和弯曲波电压分别比孔半径为0mm的收集器高约2.12倍和1.44倍。此外,缺陷频带频率的变化和相应的波局部化行为取决于特定的电边界条件和电路连接方式,最终导致输出电能的不同结果。这些发现为在声学和弹性波能收集的背景下开发高性能电子应用提供了有价值的见解和指导方针。Aerodynamic Stability and Free Vibration of FGP-Reinforced Nano-Fillers Annular Sector Microplates Exposed to Supersonic FlowEhsan Arshid, Saeed Amir, Abbas Loghman, Ömer Civalekdoi:10.1016/j.tws.2024.111610超声速流动下fgp增强纳米填料环形扇形微板的气动稳定性和自由振动Metal foams have many different uses, but they also have some weaknesses. To address this issue, scientists are exploring the possibility of adding nano-fillers to make them stronger and more rigid. As a result, there has been increased interest in analyzing structures that are made from these materials among researchers. Here and now, the authors have conducted a new study that focuses on analyzing the aerodynamic stability and free vibrational characteristics of an annular sector microplate. This is the first time that such an analysis has been done for this type of microplate. The microplate is exposed to supersonic flow and nonlinear temperature changes. The actual properties of the microplate are determined via different introduced homogenization schemes; and four distinguished patterns for both pores and nano-fillers dispersion are considered. To evaluate the reinforcements impact, two most widely recognized nano-fillers, i.e., carbon nanotubes and graphene nanoplatelets are employed and their influence on the outcomes is observed. By utilizing Hamilton's principle and performing certain mathematical operations, the equations of motion were derived and solved numerically under different boundary conditions. A case study is conducted to examine how different parameters affect the natural frequencies, corresponding mode shapes, and critical aerodynamic pressures. Since no similar research has been found, the outcomes of this work may be accounted as reference points for upcoming investigations.金属泡沫有许多不同的用途,但它们也有一些弱点。为了解决这个问题,科学家们正在探索添加纳米填充物的可能性,以使它们更坚固、更坚硬。因此,研究人员对分析由这些材料制成的结构越来越感兴趣。在此,作者进行了一项新的研究,重点分析了环形扇形微孔板的气动稳定性和自由振动特性。这是第一次对这种类型的微孔板进行这样的分析。微孔板暴露在超声速流动和非线性温度变化中。通过引入不同的均质方案来确定微孔板的实际性能;并考虑了孔隙和纳米填料分散的四种不同模式。为了评估增强剂的影响,采用了两种最广泛认可的纳米填料,即碳纳米管和石墨烯纳米片,并观察了它们对结果的影响。利用哈密顿原理,进行一定的数学运算,推导出不同边界条件下的运动方程,并对其进行数值求解。通过实例分析,研究了不同参数对固有频率、相应模态振型和临界气动压力的影响。由于没有发现类似的研究,这项工作的结果可以作为今后调查的参考点。来源:复合材料力学仿真Composites FEM

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