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【新文速递】2023年10月16日复合材料SCI期刊最新文章

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今日更新:Composite Structures 3 篇,Composites Part A: Applied Science and Manufacturing 4 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇

Composite Structures

Analytical modeling and 3D printing of locally resonant composite sandwich metamaterials with inertial amplification mechanisms

Mizukami Koichi, Abe Kentaro, Senga Takehito, Ogi Keiji

doi:10.1016/j.compstruct.2023.117626

具有惯性放大机制的局部共振复合夹层超材料的解析建模与3D打印

In this paper, a locally resonant sandwich metamaterial beam with inertial amplification mechanisms is presented for flexural vibration attenuation. This sandwich metamaterial is proposed as a lightweight structure with a low-frequency stopband. An analytical model was developed to derive the equations of motion for the resonator core and skin plate using Hamilton’s principle. Analytical solutions for the stopband boundary frequencies were derived from the equations of motion. The analytical solutions demonstrated that inertial amplification resonators can exhibit lower resonance frequencies than linear spring-mass resonators with the same weight and spring constant. It was also shown that the proposed sandwich beam exhibited a lower frequency stopband in exchange for the stopband width. Finite element method analyses and experiments were performed to investigate the frequency response of the sandwich beam. The flexural vibration of the sandwich beam was significantly attenuated within a certain frequency range. The frequency range with low transmissibility agreed well with the stopband predicted by the analytical solutions.

本文提出了一种具有惯性放大机构的局部共振夹层超材料梁,用于弯曲振动的衰减。这种夹层超材料是一种具有低频阻带的轻质结构。利用哈密顿原理建立了一个解析模型,推导了谐振器芯和蒙皮板的运动方程。由运动方程导出了阻带边界频率的解析解。解析解表明,在相同重量和弹簧常数下,惯性放大谐振器比线性弹簧-质量谐振器具有更低的谐振频率。研究还表明,该夹层梁具有较低的频率阻带,以换取阻带宽度。对夹层梁的频率响应进行了有限元分析和实验研究。夹层梁的弯曲振动在一定频率范围内得到明显衰减。低透射率的频率范围与解析解预测的阻带吻合较好。


Shear strength determining mechanism of a b 45 laminate under tensile loading

Hong Chaeyoung, Lee Sooyoung, Ji Wooseok

doi:10.1016/j.compstruct.2023.117627

拉伸载荷作用下ab45层板抗剪强度的决定机理

The shear strength of a composite material is determined as a result of a complex damage and failure process, but the detailed progression has not been clearly elucidated. Here, the mechanism of determining the strength of a ± 45 laminate under tensile loading is revealed from exquisitely designed experiments in conjunction with high-fidelity numerical simulation. Synchrotron radiation computed tomography is employed for extremely high-resolution images of damage status inside the composite just before its catastrophic failure. The ex situ observations discover the unique and consistent failure progression; one major matrix crack is initiated either in the + 45 or − 45 layer and delamination follows after the initial crack completely grows along both the fiber and transverse directions. After the delamination failure is triggered, remaining intact layers start to fail with multiple transverse matrix cracks. The failure of the intact layers is represented as a load drop in the global stress–strain curve. This sequential and interactive failure progression determines the shear strength of the ± 45 laminate. The numerical analysis finds that the location of the initial matrix crack is dependent on the microstructure. Once the matrix crack is initiated, the numerical simulation exactly reproduces the experimentally observed failure process.

复合材料的抗剪强度是一个复杂的损伤和破坏过程的结果,但详细的进展尚未清楚阐明。本文通过精心设计的实验,结合高保真数值模拟,揭示了 ± 45层合板在拉伸载荷下强度的决定机制。同步辐射计算机断层扫描被用于在复合材料灾难性失效之前对其内部损伤状态进行极高分辨率的成像。非原位观察发现了独特而一致的破坏过程;在 + 45或 − 45层中产生一个主要的基体裂纹,在初始裂纹沿纤维和横向完全扩展后发生分层。触发脱层破坏后,剩余的完整层开始破坏,形成多个横向基体裂纹。完整层的破坏表现为整体应力-应变曲线上的荷载下降。这种顺序和相互作用的破坏进程决定了 ± 45层压板的抗剪强度。数值分析发现,初始基体裂纹的位置与微观组织有关。一旦基体裂纹开始,数值模拟准确地再现了实验观察到的破坏过程。


An iso-contour method for automated fiber placement optimization of composite structures

Arsenyeva Anna, Duddeck Fabian, Thompson Harvey M.

doi:10.1016/j.compstruct.2023.117628

复合材料结构纤维自动铺放优化的等轮廓法

A new method for numerical optimization of fiber-steered composites is presented, which allows to control efficiently and effectively the curvature of the fibers of single- or multi-layer composite structures. It is based on the introduction of an artifical surface defined and controlled by a relatively small number of control points, which is optimized to identify optimal fiber orientations varying smoothly over the panels. Curvature constraints like the maximum fiber curvature constraint, MFCC, or the average fiber curvature constraint, AFCC, are respected explicitly by the method to ensure manufacturability of the composite component. Three validation cases are regarded where results of the unconstrained case are compared to those of established methods to illustrate the validity of the new approach. They are complemented by results considering curvature constraints showing that optimal structures depend strongly on the chosen curvature thresholds. Finally, a rib optimization of a wingbox structure is realized as a more complex case.

提出了一种新的纤维导向复合材料的数值优化方法,可以有效地控制单层或多层复合材料结构中纤维的曲率。它基于引入由相对较少数量的控制点定义和控制的人造表面,该表面经过优化以确定在面板上平滑变化的最佳纤维方向。该方法明确考虑了曲率约束,如最大纤维曲率约束(MFCC)或平均纤维曲率约束(AFCC),以确保复合材料部件的可制造性。通过三个验证案例,将无约束情况下的结果与已有方法的结果进行了比较,以说明新方法的有效性。考虑曲率约束的结果表明,最优结构强烈依赖于所选择的曲率阈值。最后,以更为复杂的翼箱结构为例,实现肋部优化。


Composites Part A: Applied Science and Manufacturing

In-situ micro-CT damage analysis of carbon and carbon/ glass hybrid laminates under tensile loading by image reconstruction and DVC technology

Jiang Lanxin, Xiong Hongzi, Zeng Tao, Wang Jie, Xiao Shoune, Yang Long

doi:10.1016/j.compositesa.2023.107844

基于图像重建和DVC技术的碳和碳/玻璃复合层合板拉伸载荷原位微ct损伤分析

Carbon/ glass fibre-reinforced plastic (C/GFRP) offers advantages in engineering applications due to its low cost. However, the mechanism underlying the evolution of damage in C/GFRP under tension remains unclear. Advanced in-situ micro X-ray computed tomography (µCT) is a useful method for investigating the damage evolution of fibre composites. In this study, two tensile specimens, carbon fibre reinforced plastic (CFRP) and C/GFRP, were prepared, and in-situ µCT scanning was performed at different points during the tensile process. To quantify the voids, examine the fracture morphology, and investigate the void volume fractions, three-dimensional (3D) models were constructed while employing an image reconstruction algorithm. Finally, digital volume correlation (DVC) was employed to study the 3D strain fields. The results suggest that C/GFRP exhibits a higher initial void volume ratio and a faster rate of damage evolution. The 3D strain field and stress concentration area can be used to predict the precise location where the specimen would fracture.

碳/玻璃纤维增强塑料(C/GFRP)由于其低成本而在工程应用中具有优势。然而,C/GFRP在张力作用下损伤演变的机制尚不清楚。先进的原位微x射线计算机断层扫描(µCT)是研究纤维复合材料损伤演化的有效方法。本研究制备了碳纤维增强塑料(CFRP)和C/GFRP两种拉伸试样,并在拉伸过程的不同时刻进行原位微CT扫描。为了量化孔隙,检查裂缝形态,并研究孔隙体积分数,在使用图像重建算法的同时构建了三维(3D)模型。最后,采用数字体积相关(DVC)技术对三维应变场进行了研究。结果表明,C/GFRP具有更高的初始空隙体积比和更快的损伤演化速率。三维应变场和应力集中区可以用来预测试样断裂的精确位置。


Effect of various weaving architectures on mechanical, vibration and acoustic behavior of Kevlar-Hemp intra-ply hybrid composites

Jeyaguru Sangilimuthukumar, Muthu Kumar Thiagamani Senthil, Siengchin Suchart, Subramanian Jeyanthi, Ebrahimnezhad-Khaljiri Hossein, Mavinkere Rangappa Sanjay, Khan Anish, Abuthakeer S Syath, S Rajesh

doi:10.1016/j.compositesa.2023.107845

不同织造结构对凯夫拉-大 麻复合材料力学、振动和声学性能的影响

Due to the benefits of including high stiffness, low density, low cost, ecologically benign nature and abundant availability, natural fibers are employed as reinforcement in composites. These fibers however have a few shortcomings, including poor moisture resistance and incompatibility with most matrices. Therefore, the goal of this research is to combine the benefits of natural fiber (hemp) with synthetic fiber (kevlar) to develop a hybrid composite. Hemp and Kevlar yarns were handloomed to form fabrics with different architectures such as plain, twill and basket. These hybrid fiber epoxy composites were fabricated using compression molding and the samples were subjected to mechanical testing, free vibration and acoustic emission characteristics. Hemp and Kevlar fiber composites were also fabricated for comparison purpose. The results revealed that the twill and basket weave intra ply hybrid composites exhibited the better mechanical properties when compared with the plain weave hybrids. Whereas, the free vibration results showed that the all the hybrids exhibited better performance that the mono-fiber composites. Acoustic behavior of the basket weave hybrid was found to have the highest sound transmission loss value of 13.7 dB in the higher frequency range. On the other hand, the hemp-epoxy composites exhibited the highest sound transmission level of 6.3 dB in the lower frequency range.

天然纤维具有高刚度、低密度、低成本、生态友好、可利用性丰富等优点,被广泛应用于复合材料的增强中。然而,这些纤维有一些缺点,包括抗湿性差和与大多数基质不相容。因此,本研究的目标是将天然纤维(大 麻)与合成纤维(凯夫拉尔)的优点结合起来,开发一种混合复合材料。大 麻和凯夫拉纱线被手工织造成不同结构的织物,如平纹、斜纹和篮纹。采用压缩成型的方法制备了复合材料,并对其进行了力学性能测试、自由振动和声发射特性测试。为了比较,还制备了大 麻纤维和凯夫拉纤维复合材料。结果表明,斜纹和篮织复合材料的力学性能优于平纹复合材料。而自由振动结果表明,混合纤维的性能均优于单纤维复合材料。在较高的频率范围内,篮织复合材料的声行为具有最高的传声损失值,为13.7 dB。另一方面,大 麻-环氧树脂复合材料在低频范围内的声透射率最高,为6.3 dB。


Ultrathin carbon layer coated MXene/PBO nanofiber films for high performance electromagnetic interference shielding and thermal stability

Gong Kaijie, Peng Yanmeng, Liu An, Qi Shuhua, Qiu Hua

doi:10.1016/j.compositesa.2023.107857

超薄碳层涂层的MXene/PBO纳米纤维薄膜具有高性能的电磁干扰屏蔽和热稳定性

In this study, a carbon layer coated MXene/poly(p-phenylene-2,6-benzobisoxazole) nanofibers (PNFs) (MXene/PNF@C) EMI shielding composite film was obtained through polymer infiltration and pyrolysis (PIP) technique. The introduction of the carbon layer improved both the electrical and thermal conductive pathways of the film leading to the enhancement of its electrical conductivity(σ), thermal conductivity coefficient (λ) and EMI shielding effectiveness (SE). Meanwhile, thermal annealing reduced the defects of PBO molecular chains and improved the mechanical properties of the composite film. When the content of MXene is 50 wt% and the thickness of the film is only 37 μm, MP50@C-400 composite film has the best comprehensive properties, with the σ, λ, specific EMI SE (SEt) and tensile strength is 1760 S/m, 5.64 W/(m·K), 1108.1 dB/mm and 66.8 MPa, respectively, and its weight loss is only 24.1% at 800°C. The composite film provides important application prospects in 5G communication technology, wearable equipment and artificial intelligence.

本研究采用聚合物渗透热解(PIP)技术制备了碳层包覆MXene/聚(对苯-2,6-苯并异恶唑)纳米纤维(MXene/PNF@C)电磁干扰屏蔽复合膜。碳层的引入改善了薄膜的导电和导热途径,从而提高了薄膜的电导率(σ)、导热系数(λ)和电磁干扰屏蔽效能(SE)。同时,热处理减少了PBO分子链的缺陷,提高了复合膜的力学性能。当MXene含量为50 wt%,薄膜厚度仅为37 μm时,MP50@C-400复合薄膜的综合性能最好,σ、λ、比EMI SE (SEt)和抗拉强度分别为1760 S/m、5.64 W/(m·K)、1108.1 dB/mm和66.8 MPa, 800℃时的失重率仅为24.1%。复合薄膜在5G通信技术、可穿戴设备、人工智能等方面具有重要的应用前景。


Facile in-situ synthesis of carbon black@poly(ionic liquid) composites with a smooth U-link chain macrostructure within surfactant-free ionic liquid microemulsions

Wang Aili, Ye Tingting, Liu Yuyang, Song Minxin, Lou Nan, Wu Guangshun, Niu Yuzhong, Zheng Tanghong

doi:10.1016/j.compositesa.2023.107859

无表面活性剂离子液体微乳液中具有光滑u链结构的碳black@poly(离子液体)复合材料的原位合成

Poly(ionic liquid)s show tremendous potential in the application of strain sensing. However, their development is limited by tedious fabrication techniques and the instability factor of existing poly(ionic liquid)s-based strain sensing materials. In this work, we in situ synthesized a novel carbon black and poly(ionic liquid) composites (CB@PILs) by performing thiol-ene click reaction within a surfactant-free ionic liquid microemulsion. The successful construction and reaction of the composites were confirmed by FTIR, XRD, XPS, SEM, TG/DSC, strain test, and conductivity analyses. Results demonstrated that a composite that has a smooth U-link chain macrostructure could be prepared by altering the carbon black content at 3 wt%, and the resultant polymer presented good thermal stability and strain sensing performance. The mass ratio between polyethylene glycol diacrylate and hydroxyethyl methacrylate could further improve the conductivity and mechanical properties of CB@PIL composites. This work provides a potential avenue for designing CB@PIL composites, thus making them viable for strain sensing.

聚离子液体在应变传感领域显示出巨大的应用潜力。然而,它们的发展受到繁琐的制造技术和现有的基于多离子液体的应变传感材料的不稳定性因素的限制。在这项工作中,我们通过在无表面活性剂的离子液体微乳液中进行巯基点击反应,原位合成了一种新型的炭黑和聚离子液体复合材料(CB@PILs)。通过FTIR, XRD, XPS, SEM, TG/DSC,应变测试和电导率分析证实了复合材料的成功构建和反应。结果表明,当炭黑含量为3 wt%时,可以制备出具有光滑u链宏观结构的复合材料,该聚合物具有良好的热稳定性和应变传感性能。聚乙二醇二丙烯酸酯与甲基丙烯酸羟乙酯的质量比可以进一步提高CB@PIL复合材料的电导率和力学性能。这项工作为设计CB@PIL复合材料提供了一条潜在的途径,从而使它们能够用于应变传感。


Composites Part B: Engineering

Bone-targeted engineered bacterial extracellular vesicles delivering miRNA to treat osteoporosis

Liu Han, Wu Yan, Wang Fuxiao, Wang Sicheng, Ji Ning, Wang Mingkai, Zhou Guangyin, Han Ruina, Liu Xinru, Weng Weizong, Tan Haoqi, Jing Yingying, Zhang Wencai, Zhang Hao, Shi Zhongmin, Su Jiacan

doi:10.1016/j.compositesb.2023.111047

骨靶向工程细菌细胞外囊泡递送miRNA治疗骨质疏松症

Osteoporosis (OP), characterized by decreased bone density and destruction of bone microstructure, is a common systemic bone disease in the elderly. Conventional therapies suffer from poor targeting and long-term toxicity. Engineered bacterial extracellular vesicles (BEVs) containing bioactive molecules show great potential as alternative OP therapies. Here, we developed a delivery system based on BEVs secreted probiotic Lactobacillus rhamnosus GG (LGG). Bone-targeting peptides were anchored on the LGG-EVs membranes, which endowed LGG-EVs the ability to deliver intrinsic miRNA to bone microenvironment. Bone-targeted LGG-EVs (BT-LGG-EVs) exhibited great bone targeting capability without significant toxicity. BT-LGG-EVs not only promoted osteogenic differentiation and mineralization but also inhibited the formation of osteoclasts. Furthermore, BT-LGG-EVs were demonstrated to be able to attenuate the OVX-induced osteoporotic phenotypes. Our study demonstrated that BT-LGG-EVs hold great promise for use as an innovative, safe, and effective solution for the treatment of OP.

骨质疏松症(Osteoporosis, OP)是一种常见的老年人全身性骨病,以骨密度降低和骨微结构破坏为特征。传统疗法存在靶向性差和长期毒性的问题。含有生物活性分子的工程细菌细胞外囊泡(BEVs)作为OP的替代疗法具有很大的潜力。在此,我们开发了一种基于bev分泌的益生菌鼠李糖乳杆菌GG (LGG)的递送系统。骨靶向肽被锚定在lgg - ev膜上,这赋予了lgg - ev向骨微环境传递内在miRNA的能力。骨靶向lgg - ev (bt - lgg - ev)表现出良好的骨靶向能力,且没有明显的毒性。bt - lgg - ev不仅能促进成骨分化和矿化,还能抑制破骨细胞的形成。此外,bt - lgg - ev被证明能够减轻ovx诱导的骨质疏松表型。我们的研究表明,bt - lgg - ev有望作为一种创新、安全、有效的治疗OP的解决方案。


Composites Science and Technology

An ultrasensitive flexible strain sensor based on CNC/CNTs/MXene/TPU fibrous mat for human motion, sound and visually personalized rehabilitation training monitoring

Cui Meijie, Wu Songkai, Li Jiannan, Zhao Yi, Zhai Wei, Dai Kun, Liu Chuntai, Shen Changyu

doi:10.1016/j.compscitech.2023.110309

 

一种基于CNC/CNTs/MXene/TPU纤维垫的超灵敏柔性应变传感器,用于人体运动、声音和视觉个性化康复训练监测

Personalized rehabilitation training provides maximum help to stroke patients to alleviate the after-effects and restore the body to normal function. However, available monitoring devices have the disadvantages of being large, requiring professional guidance, and lacking intuitive signal display capabilities. Herein, a bio-inspired wearable high-performance strain sensor with a simple structure can simultaneous electrical signals and optical visualization in response to external stimuli. The sensor comprises a conductive layer with significant electromechanical behaviors of cellulose nanocrystals (CNC)/carbon nanotubes (CNTs)/MXene nanohybrid network, and a stretchable elastomer layer consisting of thermoplastic polyurethane and fluorescent agent. Benefiting from the designed microcracks and fluorescent material, the strain sensor exhibits ultra-high sensitivity (476800), ultra-low detection limit (0.005%), low response time (60 ms), wide working range (0–100%), and enables strain visualization for applications in visually rehabilitation training monitoring. Based on these sensing characteristics, the sensor shows great advantages in human motion and sound monitoring, the integration of digital signals and visual images makes it show great potential in visually personalized rehabilitation training monitoring.

个性化康复训练为脑卒中患者减轻后遗症,恢复身体正常功能提供了最大的帮助。但是现有的监控设备存在体积大、需要专业人员指导、缺乏直观的信号显示能力等缺点。本文设计了一种结构简单的仿生可穿戴高性能应变传感器,该传感器可以响应外部刺 激同时发出电信号和光学可视化。该传感器包括具有显著机电行为的纤维素纳米晶体(CNC)/碳纳米管(CNTs)/MXene纳米混合网络导电层和由热塑性聚氨酯和荧光剂组成的可拉伸弹性体层。得益于所设计的微裂纹和荧光材料,该应变传感器具有超高灵敏度(476800)、超低检出限(0.005%)、低响应时间(60 ms)、宽工作范围(0-100%),可实现应变可视化,用于视觉康复训练监测。基于这些传感特性,传感器在人体运动和声音监测方面显示出巨大的优势,数字信号与视觉图像的融合使其在视觉个性化康复训练监测方面显示出巨大的潜力。



来源:复合材料力学仿真Composites FEM
ACTMechanicalOpticalSystemInspire振动断裂复合材料光学通信声学裂纹材料仿生控制人工智能
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【新文速递】2023年10月8日复合材料SCI期刊最新文章

今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 5 篇,Composites Science and Technology 3 篇Composite StructuresAnalytical homogenization for equivalent in-plane elastic moduli of multi-material honeycombsHuang Li, Liu Xiang, Liu Xiao, Zhao Xueyidoi:10.1016/j.compstruct.2023.117586多材料蜂窝等效面内弹性模量的分析均质化3D printable multi-material honeycombs have attracted increasing interest recently due to the improved elastic moduli, buckling and energy absorption properties. This paper proposes an analytical homogenization for the equivalent in-plane elastic moduli (EIEM) of multi-material honeycombs. First, the axial and bending stiffness of a cantilever beam consist of three sections made of different materials is formulated. Then based on unit cell method and cantilever beam model, the closed-form expressions of EIEM are proposed by fully considering the deformations of both joints and cell walls with arbitrary stiffness, which are sufficiently general to be applied to hexagonal, auxetic and rectangular multi-material honeycombs and validated very well by numerical simulations and experiments. Furthermore, the effects of geometric and material distribution ratios on EIEM are discussed. The results show that the geometric and material distribution ratios of inclined cell wall have a significant effect on all five EIEM while that of vertical cell wall shows a significant effect on shear modulus but only a slight effect on y- direction elastic moduli. Compared with single-material honeycombs, changing joint stiffness has a significant effect on the equivalent Young’s moduli and shear modulus but a slight effect on Poisson’s ratios.可三维打印的多材料蜂窝由于具有更好的弹性模量、屈曲和能量吸收特性,最近引起了越来越多的关注。本文提出了一种多材料蜂窝的等效面内弹性模量(EIEM)分析均质化方法。首先,计算由三种不同材料组成的悬臂梁的轴向和弯曲刚度。然后,基于单胞法和悬臂梁模型,充分考虑了具有任意刚度的接缝和胞壁的变形,提出了 EIEM 的闭式表达式,这些表达式具有足够的通用性,可应用于六边形、辅助形和矩形等多种材料蜂窝,并通过数值模拟和实验得到了很好的验证。此外,还讨论了几何和材料分布比对 EIEM 的影响。结果表明,倾斜蜂窝壁的几何形状和材料分布比对五种 EIEM 都有显著影响,而垂直蜂窝壁的几何形状和材料分布比对剪切模量有显著影响,但对 y 方向的弹性模量只有轻微影响。与单一材料蜂窝相比,改变连接刚度对等效杨氏模量和剪切模量有显著影响,但对泊松比影响轻微。Composites Part A: Applied Science and ManufacturingPin-Loaded Tensile Behavior and Failure Analysis of CF/PEKK Composites under Extreme TemperatureLi Xiaoqi, Kumar Sanjay, Hwang Dong-Wook, Shin Do-Hoon, Kim Yun-Haedoi:10.1016/j.compositesa.2023.107823CF/PEKK 复合材料在极端温度下的销装拉伸行为和失效分析This study investigated pinned-joint bearing strengths and failure behaviors of carbon-fiber-reinforced polyetherketoneketone (CF/PEKK) composites at different temperatures, with varying the width-to-hole diameter (W/D) and edge distance-to-hole diameter (E/D) ratios. Increasing the W/D ratio substantially amplified the pin load capacity, with net tension failure at W/D = 1.5 and bearing failure at W/D ≥ 2, irrespective of temperature. The W/D ratio exerted major influence on the bearing strength, maximum bearing strength was lower at low temperatures (LT; −60℃) (390 MPa) and high temperatures (HT; 200℃) (385 MPa) than that at room temperature (RT; 25℃) (428 MPa). In comparison to RT, a reduction in specimen thickness at bearing area and accelerated localized kink collapse in 0° lamina was observed for LT. The increased ductility of matrix at HT, resulting in fewer matrix cracks. These findings indicate the outstanding bearing load resistance of CF/PEKK composites, supporting their suitability for utilization in high-performance structures.本研究研究了碳纤维增强聚醚醚酮(CF/PEKK)复合材料在不同温度下的销钉连接承载强度和失效行为,并改变了孔径宽度比(W/D)和孔径边缘距离比(E/D)。无论温度如何,W/D 比的增加都会大大提高针的承载能力,W/D = 1.5 时会出现净拉伸破坏,W/D ≥ 2 时会出现承载破坏。W/D 比对轴承强度有很大影响,低温(LT;-60℃)(390 兆帕)和高温(HT;200℃)(385 兆帕)时的最大轴承强度低于室温(RT;25℃)(428 兆帕)时的最大轴承强度。与室温(RT)相比,在低温(LT)条件下,承载区域的试样厚度减小,0°薄片的局部扭结塌陷加速。HT 时基体的延展性增加,导致基体裂纹减少。这些研究结果表明,CF/PEKK 复合材料具有出色的抗承载能力,因此适合用于高性能结构。Composites Part B: EngineeringA design methodology of composite scarf repairs using artificial intelligenceYan Bing, Tong Mingbo, Furtado Carolina, Danzi Federico, Arteiro Albertino, Camanho Pedro P.doi:10.1016/j.compositesb.2023.111020使用人工智能的复合材料围巾修补设计方法Composite Scarf Bonded (CSB) based techniques are highly effective in structural connections and structural repairs. In this article, a preliminary design methodology based on Machine Learning (ML) algorithms trained on databases obtained via a semi-analytical approach is proposed and used to generate the design space for CSB structures under tensile loads. This ML framework introduces the one-hot encoding technology to deal with discrete inputs, such as multiple stacking sequences. Four ML algorithms, Adaptive Boosting, Gradient Boosting Regression, Extreme Gradient Boosting, and Artificial Neural Networks are studied. The best-performing model is then used to generate the damage tolerance-based design space for CSB structures made from fabric and unidirectional prepregs, accounting for material and geometrical uncertainties. Very good representations of the design space and accuracy in structural strength and failure mode are obtained. An optimal scarf angle zone, where laminate and adhesive fail simultaneously, was identified using the proposed framework. This design framework opens new avenues for the selection of material and layup configuration in structural design and enables the fast estimation of the optimal scarf angle range for the preliminary design of CSB structures.基于复合材料帷幕粘结(CSB)的技术在结构连接和结构修复方面非常有效。本文提出了一种基于机器学习(ML)算法的初步设计方法,该算法在通过半分析方法获得的数据库上经过训练,用于生成拉伸载荷下 CSB 结构的设计空间。该 ML 框架引入了单次编码技术,以处理离散输入,如多个堆叠序列。研究了四种 ML 算法:自适应提升、梯度提升回归、极梯度提升和人工神经网络。然后,使用性能最佳的模型为织物和单向预浸料制成的 CSB 结构生成基于损伤容限的设计空间,并考虑材料和几何不确定性。结果很好地体现了设计空间以及结构强度和失效模式的精确性。利用所提出的框架,确定了层压板和粘合剂同时失效的最佳围边角区域。该设计框架为在结构设计中选择材料和铺层配置开辟了新的途径,并能为 CSB 结构的初步设计快速估算最佳围边角范围。Ageing effect on the low-velocity impact response of 3D printed continuous fibre reinforced compositesFerreira L.M., Aranda M.T., Muñoz-Reja M., Coelho C., Távara L.doi:10.1016/j.compositesb.2023.111031老化对 3D 打印连续纤维增强复合材料低速冲击响应的影响This paper aims to analyse the low-velocity impact performance of 3D printed continuous carbon fibre reinforced composites manufactured by fused deposition modelling. Moreover, the effect of ageing on the impact properties and visual damage is studied. This evaluation is crucial for understanding the long-term behaviour and durability of these materials, enabling better design and engineering decisions in various applications where impact resistance is paramount. Low-velocity impact tests were conducted on specimens aged 1, 7, 15 and 30 days. An instrumented drop-weight testing machine was employed for the tests. The dimensions and layup sequence of the composite specimens were designed following the recommendations outlined in the ASTM D7136/D7136M standard for unidirectional composite tapes. Results showed that the initial elastic part slightly reduces with age. In addition, the severity of visual damage in the specimens clearly varied with age. The older specimens present the less visible damage but also the lower impact energy absorption.本文旨在分析通过熔融沉积模型制造的三维打印连续碳纤维增强复合材料的低速冲击性能。此外,还研究了老化对冲击性能和视觉损伤的影响。这项评估对于了解这些材料的长期行为和耐久性至关重要,有助于在抗冲击性至关重要的各种应用中做出更好的设计和工程决策。对龄期为 1、7、15 和 30 天的试样进行了低速冲击试验。测试使用了一台带仪器的落重测试机。复合材料试样的尺寸和层叠顺序是按照 ASTM D7136/D7136M 单向复合材料带标准中的建议设计的。结果表明,初始弹性部分会随着时间的推移而略微减小。此外,试样视觉损伤的严重程度明显随使用年限而变化。使用年限越长的试样,可见损伤越小,但冲击能量吸收能力也越低。Lightweight composite gypsum boards with clay mineral and glass fibre for enhanced fire-resistanceWang Sen, Pancheti Jashnav, Xi Yunfei, Mahendran Mahendoi:10.1016/j.compositesb.2023.111044含有粘土矿物和玻璃纤维的轻质复合石膏板可增强防火性能The current strategy for developing fire-resistant gypsum boards is mainly based on adding porous materials. However, these additives are generally weaker in strength due to higher porosity and are usually produced via energy-intensive processes with relatively higher costs. This paper presents a novel strategy to fabricate lightweight fire-resistant composite gypsum boards through the synergistic coupling of naturally abundant clay mineral - palygorskite (0–30 wt%) and cost-effective glass fibre (0.5 wt%). The bulk density of the obtained boards decreases from 1059 (0 wt% palygorskite addition) to 795 kg/m3 (30 wt% palygorskite). Attributed to the higher initial porosity, reduced shrinkage above 650 °C, and the decomposition of CaSO4 above 925 °C to absorb heat, the ambient side temperature of a composite gypsum board after a 90-min standard fire test is reduced significantly by 150 °C. The new board shows a commendable post-fire strength of 0.15 MPa and fewer cracks than commercial products, which are caused by increased porosity and the bridging effect of glass fibre and sintered palygorskite particles. Through the effective integration of in-situ high-temperature X-ray diffraction, thermal mass loss/heat exchange, and thermal dilatometry, the real-time thermal behaviours of composite gypsum boards are characterised, and the microstructure, physical and mechanical properties and fire resistance are investigated.目前开发防火石膏板的策略主要是添加多孔材料。然而,由于孔隙率较高,这些添加剂的强度通常较弱,而且通常采用能源密集型工艺生产,成本相对较高。本文提出了一种新的策略,即通过将天然丰富的粘土矿物--叶蜡石(0-30 wt%)和具有成本效益的玻璃纤维(0.5 wt%)协同耦合,制造轻质防火复合石膏板。所获得板材的体积密度从 1059(白云石添加量为 0 wt%)降至 795 kg/m3(白云石添加量为 30 wt%)。由于初始孔隙率较高、650 °C以上收缩率降低以及 CaSO4 在 925 °C以上分解吸热,复合石膏板在 90 分钟标准防火测试后的环境侧温度显著降低了 150 °C。与商业产品相比,新石膏板的火后强度达到 0.15 兆帕,裂缝更少,这是因为孔隙率增加以及玻璃纤维和烧结钙钛矿颗粒的桥接效应所致。通过有效整合原位高温 X 射线衍射、热质量损失/热交换和热膨胀仪,对复合石膏板的实时热行为进行了表征,并对其微观结构、物理和机械性能以及耐火性进行了研究。A review on advanced cutting tools and technologies for edge trimming of carbon fibre reinforced polymer (CFRP) compositesGeier Norbert, Xu Jinyang, Poór Dániel István, Dege Jan Hendrik, Davim J Paulodoi:10.1016/j.compositesb.2023.111037碳纤维增强聚合物 (CFRP) 复合材料切边用先进切割工具和技术综述Recently, the use of carbon fibre reinforced polymer (CFRP) composites is predominant and will grow further. Although these fibrous composites are often manufactured near net shape, their mechanical machining is often required to meet dimensional tolerances. Considering the difficult-to-cut nature of CFRP composites, the technology planning of edge trimming of CFRPs poses significant challenges and obstacles. Therefore, the main aim of this study is to critically review and discuss challenges, recent expertise and experience gained in the area of edge trimming CFRPs. On the one hand, conventional and advanced edge trimming technologies are reviewed and compared. On the other hand, advanced cutting tools are presented and discussed. Finally, future scope and prospects are highlighted to determine further research scopes in the edge trimming of CFRP composites.最近,碳纤维增强聚合物(CFRP)复合材料的使用占主导地位,并将进一步增长。尽管这些纤维状复合材料在制造时通常接近净形,但为了满足尺寸公差要求,通常需要对其进行机械加工。考虑到 CFRP 复合材料难以切割的特性,CFRP 边缘修整的技术规划面临着巨大的挑战和障碍。因此,本研究的主要目的是批判性地回顾和讨论 CFRP 边缘修整领域所面临的挑战、最新的专业知识和获得的经验。一方面,对传统和先进的切边技术进行回顾和比较。另一方面,介绍并讨论了先进的切割工具。最后,强调了未来的范围和前景,以确定 CFRP 复合材料切边的进一步研究范围。Ferroconcrete-inspired construction of wearable composites with a natural leather matrix for excellent neutron-shielding performanceZhou Jibo, Li Hao, Wen Chun, Wang Yaping, Liao Xuepin, Shi Bidoi:10.1016/j.compositesb.2023.111043 受铁混凝土启发,用天然皮革基质制造具有优异中子屏蔽性能的可穿戴复合材料In various sectors, including medical radiotherapy, aerospace exploration, and nuclear energy, the necessity for advanced neutron-shielding materials has escalated. However, these materials often exhibit poor mechanical performance and limited adaptability. To address these shortcomings, this study introduces a novel approach inspired by ferroconcrete construction to develop wearable neutron-shielding materials. This method utilizes the collagen fiber-supported framework present in natural leather, serving as a flexible skeleton, and employs functionalized B4C nanoparticles and paraffin as fillers. The interconnected voids and the unique hierarchical structure of the collagen fibers work synergistically to enable uniform dispersion of B4C nanoparticles, thus enriching the resultant composites with superior neutron-shielding performance. The composite material prepared through this method exhibits a remarkable neutron-shielding effectiveness of 96.93 % and a high linear attenuation coefficient of 17.46 cm−1, outperforming other shielding materials. Additionally, the three-dimensional (3D) woven network of the collagen fiber-supported framework offers impressive mechanical properties, including a tensile strength of 28.59 MPa. This innovative design strategy for creating new wearable neutron-shielding materials paves the way for manufacturing advanced neutron-protective clothing and propels a new structural design with elevated shielding and mechanical performance.在医疗放射治疗、航空航天探索和核能等各个领域,对先进中子屏蔽材料的需求不断增加。然而,这些材料往往表现出机械性能差、适应性有限等缺点。针对这些不足,本研究从铁混凝土结构中汲取灵感,引入了一种新方法来开发可穿戴的中子屏蔽材料。该方法利用天然皮革中的胶原纤维支撑框架作为柔性骨架,并采用功能化 B4C 纳米粒子和石蜡作为填充物。胶原纤维相互连接的空隙和独特的分层结构协同作用,使 B4C 纳米粒子均匀分散,从而使制备的复合材料具有优异的中子屏蔽性能。通过这种方法制备的复合材料具有显著的中子屏蔽效果(96.93%)和高线性衰减系数(17.46 cm-1),优于其他屏蔽材料。此外,胶原纤维支撑框架的三维(3D)编织网络具有令人印象深刻的机械性能,包括 28.59 兆帕的抗拉强度。这种用于制造新型可穿戴中子屏蔽材料的创新设计策略为制造先进的中子防护服铺平了道路,并推动了具有更高的屏蔽和机械性能的新型结构设计。Composites Science and TechnologyStrong and tough glass composites with a partially segmented micro-architectureWang Qi, Ding Li, Wang Shuo, Arola Dwayne, An Bingbing, Zhang Dongshengdoi:10.1016/j.compscitech.2023.110301 具有部分分割微结构的强韧玻璃复合材料Inspired by the composition of “hard” fin rays and “soft” collagen and the non-segmented and segmented composite structure of fish fins, we propose a partially segmented laminated structure design concept to overcome the brittleness of hard materials. Here, laminated glass composites with a partially segmented micro-architecture are fabricated using a laser engraving approach and a mechanical evaluation of the structure is performed. It is found that the involvement of segmentation enables an incremental cracking mechanism by restraining cracks in segments and a tablet sliding mechanism, thereby producing an unusual combination of strength and toughness. The strength of the partially segmented glass composite is controlled by the depth of segmentation, while the enhancement of toughness is controlled by a superposition of the cracking and sliding mechanisms. The balanced zone involving these mechanisms enables simultaneous improvement of strength and toughness. Additionally, the strength and toughness of partially segmented glass composite can be tuned by varying segment thickness and changing the interlayer materials.受 "硬 "鳍射线和 "软 "胶原蛋白的组成以及鱼鳍的非分段和分段复合结构的启发,我们提出了一种部分分段层压结构的设计理念,以克服硬质材料的脆性。在此,我们采用激光雕刻方法制造了具有部分分段微结构的层压玻璃复合材料,并对该结构进行了力学评估。研究发现,分段的参与通过限制分段裂纹和平板滑动机制实现了增量开裂机制,从而产生了不同寻常的强度和韧性组合。部分分段玻璃复合材料的强度由分段深度控制,而韧性的增强则由开裂机制和滑动机制的叠加控制。这些机制的平衡区可同时提高强度和韧性。此外,部分分段玻璃复合材料的强度和韧性可以通过改变分段厚度和改变层间材料来调整。Superelastic and thermal insulating multilayer organic-inorganic hybrid aerogel built from boron nitride nanoribbons and aramid nanofibersFeng Lei, Wei Peng, Ding Siyuan, Song Qiang, Zhang Jiaxu, Wang Chenhuan, Guo Liyuan, Xu Dongfang, Song Haojiedoi:10.1016/j.compscitech.2023.110277 由氮化硼纳米带和芳纶纳米纤维制成的超弹性和隔热多层有机-无机混合气凝胶Thermally insulating aramid nanofiber (ANF) aerogels enable a wide range of applications but are limited by their low mechanical elasticity. Efficient design of aerogels’ components and microstructures is crucial yet remains highly challenging for effectively improving the flexibility of ANF aerogels. Here, for the first time, we report the incorporation of boron nitride nanoribbons (BNNRs) into ANF aerogel to form a multilayer BNNR/ANF hybrid aerogel, which is prepared by suspension mixing of BNNRs and ANFs followed by a vacuum-assisted and directional solidification process. Flexible BNNRs with a high aspect ratio are uniformly embedded in the ANF networks, giving the ANF aerogel an extremely high mechanical deformability (up to 60 % compressive strain), capable of retaining its elasticity even after 100 compression cycles or in liquid N2 (−196 °C). Moreover, the introduction of BNNRs does not reduce the thermal insulation capacity of ANF aerogels, while significantly improving their thermal stability and fire resistance. These excellent multifunctionality benefits from the synergistic effect of organic–inorganic components and the multilayer structure of aerogel. This work paves the avenue for developing next-generation elastic and thermal insulating materials with great potential for widespread applications.绝热芳纶纳米纤维(ANF)气凝胶具有广泛的应用前景,但由于其机械弹性较低而受到限制。气凝胶成分和微结构的高效设计至关重要,但要有效提高芳纶纳米纤维气凝胶的弹性仍极具挑战性。在这里,我们首次报道了在 ANF 气凝胶中加入氮化硼纳米带(BNNR)以形成多层 BNNR/ANF 混合气凝胶。高纵横比的柔性 BNNR 均匀地嵌入 ANF 网络中,使 ANF 气凝胶具有极高的机械变形能力(压缩应变高达 60%),即使在 100 次压缩循环或在液态 N2(-196 °C)中也能保持弹性。此外,引入 BNNRs 不会降低 ANF 气凝胶的隔热能力,同时还能显著提高其热稳定性和耐火性。这些优异的多功能性得益于有机-无机成分的协同效应和气凝胶的多层结构。这项工作为开发下一代弹性和隔热材料铺平了道路,具有广泛应用的巨大潜力。Lowering the percolation threshold when filling polystyrene with surface-functionalized carbon nanohornsSedelnikova Olga V., Baskakova Kseniya I., Bychanok Dzmitry S., Maksimovskiy Eugene A., Bulusheva Lyubov G., Okotrub Alexander V.doi:10.1016/j.compscitech.2023.110294 用表面功能化碳纳米角填充聚苯乙烯时降低渗流阈值Carbon nanohorns (CNHs) are highly porous material composed of spherical aggregates of short carbon tubes with closed ends. Given their significant potential for a variety of applications, including electromagnetic shielding, it is important to tune the morphology and surface functionality of CNHs. In this study, CNHs functionalized with –CHx groups were synthesized by arc discharge of a graphite rod with the addition of toluene vapor. The resulting material was used as a filler for polystyrene (PS) composites, whose electromagnetic properties were studied over the frequency range of 1 kHz–4 GHz. Our research showed that functionalization increases the electrostatic association of CNHs, thereby facilitating the formation of conduction paths. As a result, polymer composites containing functionalized CNHs exhibit improved electromagnetic response and lower electrical percolation threshold. The insights gathered from this study provide crucial information on the relation between charge transport and polarization phenomena, the structure of CNHs, their surface state, and their arrangement in the matrix. This information could potentially aid in the further development of this exceptional material.纳米碳管(CNHs)是一种高多孔材料,由末端封闭的短碳管球形聚集体组成。鉴于其在电磁屏蔽等多种应用中的巨大潜力,调整 CNHs 的形态和表面功能非常重要。在本研究中,通过对石墨棒进行电弧放电并加入甲苯蒸汽,合成了具有 -CHx 基团功能的 CNH。所得材料用作聚苯乙烯(PS)复合材料的填料,研究了其在 1 kHz-4 GHz 频率范围内的电磁特性。我们的研究表明,官能化增加了 CNHs 的静电结合,从而促进了传导路径的形成。因此,含有官能化 CNHs 的聚合物复合材料具有更好的电磁响应和更低的电渗阈值。这项研究提供了有关电荷传输和极化现象、CNHs 结构、表面状态及其在基体中的排列之间关系的重要信息。这些信息可能有助于这种特殊材料的进一步发展。来源:复合材料力学仿真Composites FEM

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