首页/文章/ 详情

【新文速递】2023年10月21日复合材料SCI期刊最新文章

26天前浏览753

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

Composite Structures

Stochastic interpretable machine learning based multiscale modeling in thermal conductivity of Polymeric Graphene-enhanced composites

Liu Bokai, Lu Weizhuo, Olofsson Thomas, Zhuang Xiaoying, Rabczuk Timon

doi:10.1016/j.compstruct.2023.117601

基于随机可解释机器学习的聚合物石墨烯增强复合材料导热性多尺度建模

We introduce an interpretable stochastic integrated machine learning based multiscale approach for the prediction of the macroscopic thermal conductivity in Polymeric graphene-enhanced composites (PGECs). This method encompasses the propagation of uncertain input parameters from the meso to macro scale, implemented through a foundational bottom-up multi-scale framework. In this context, Representative Volume Elements in Finite Element Modeling (RVE-FEM) are employed to derive the homogenized thermal conductivity. Besides, we employ two sets of techniques: Regression-tree-based methods (Random Forest and Gradient Boosting Machine) and Neural networks-based approaches (Artificial Neural Networks and Deep Neural Networks). To ascertain the relative influence of factors on output estimations, the SHapley Additive exPlanations (SHAP) algorithm is integrated. This interpretable machine learning methodology demonstrates strong alignment with published experimental data. It holds promise as an efficient and versatile tool for designing new composite materials tailored to applications involving thermal management.

我们介绍了一种基于随机综合机器学习的多尺度可解释方法,用于预测聚合物石墨烯增强复合材料(PGEC)的宏观热导率。该方法通过自下而上的多尺度基础框架,将不确定的输入参数从中观尺度传播到宏观尺度。在此背景下,我们采用了有限元建模中的代表性体积元素(RVE-FEM)来推导均质化热导率。此外,我们还采用了两套技术:基于回归树的方法(随机森林和梯度提升机)和基于神经网络的方法(人工神经网络和深度神经网络)。为了确定各因素对输出估计的相对影响,还集成了 SHapley Additive exPlanations(SHAP)算法。这种可解释的机器学习方法与已公布的实验数据非常吻合。它有望成为设计新型复合材料的高效多功能工具,为涉及热管理的应用量身定制。


Composites Part A: Applied Science and Manufacturing

Electromagnetic interference shielding composites and the foams with gradient structure obtained by selective distribution of MWCNTs into hard domains of thermoplastic polyurethane

Wang Xiaohan, Zou Fangfang, Zhao Yishen, Li Guangxian, Liao Xia

doi:10.1016/j.compositesa.2023.107861

电磁干扰屏蔽复合材料,以及通过在热塑性聚氨酯硬域中选择性分布 MWCNT 而获得的梯度结构泡沫

In this paper, multilayer thermoplastic polyurethane (TPU)/multiwalled carbon nanotubes (MWCNTs) electromagnetic interference shielding composite foams with gradient structure was prepared. The gradient distribution of effective concentration of filler and cell size were realized by selective distribution of MWCNTs into hard domains of TPU, which improved interlayer interface polarization of electromagnetic waves and impedance matching between the material and the air. The average electromagnetic interference shielding efficiency (EMI SE) of TPU/MWCNTs composites with gradient structure is 1.2 times larger than that of homogeneous composites. After foaming, the average EMI SE of the gradient foams was higher than that of the homogeneous foams, with maximum average EMI SE of 35.4 dB. This work is the first time to correlate the interaction of fillers with the soft domains and hard domains of TPU and EMI shielding performance, providing a feasible method for designing lightweight composites with low filler and better EMI shielding performance.

本文制备了具有梯度结构的多层热塑性聚氨酯(TPU)/多壁碳纳米管(MWCNTs)电磁干扰屏蔽复合泡沫。通过将 MWCNTs 选择性地分布在 TPU 的硬域中,实现了填料有效浓度和单元尺寸的梯度分布,从而改善了电磁波的层间界面极化以及材料与空气之间的阻抗匹配。梯度结构 TPU/MWCNTs 复合材料的平均电磁干扰屏蔽效率(EMI SE)是均质复合材料的 1.2 倍。发泡后,梯度泡沫的平均 EMI SE 高于均质泡沫,最大平均 EMI SE 为 35.4 dB。这项研究首次将填料与热塑性聚氨酯软域和硬域的相互作用与 EMI 屏蔽性能联系起来,为设计低填料、EMI 屏蔽性能更好的轻质复合材料提供了可行的方法。


Composites Part B: Engineering

Multifunctional basalt fiber polymer composites enabled by carbon nanotubes and graphene

Balaji K.V., Shirvanimoghaddam Kamyar, Naebe Minoo

doi:10.1016/j.compositesb.2023.111070

利用碳纳米管和石墨烯实现玄武岩纤维聚合物复合材料的多功能性

Basalt fiber (BF) is an eco-friendly fiber that can mitigate environmental footprint by enabling lightweight composite systems and components. When combined with carbonaceous structures such as carbon nanotubes (CNT) and graphene, these fibers can form multi-scale composites with remarkable potential for creating smart composites with added functionalities. In this paper, we review various fiber treatment methods used for nanomaterials, which include chemical vapor deposition (CVD), electrophoretic deposition, sizing, dipping, and chemical grafting. Compared to matrix modification, fiber treatment methods are more efficient in facilitating better load transfer between the matrix resin and fiber reinforcement through a nanomaterial bridge. Custom sizing with nanomaterials and CVD processes without a catalyst have been found the most effective methods for immobilizing nanomaterials onto the fibers. This advancement sets the stage for a new generation of sustainable and functional polymer composites that can support a circular economy.

玄武岩纤维(BF)是一种生态友好型纤维,可实现复合材料系统和组件的轻量化,从而减少对环境的影响。当与碳纳米管(CNT)和石墨烯等碳质结构相结合时,这些纤维可以形成多尺度复合材料,在创造具有附加功能的智能复合材料方面具有显著的潜力。本文综述了用于纳米材料的各种纤维处理方法,包括化学气相沉积(CVD)、电泳沉积、上浆、浸渍和化学接枝。与基体改性相比,纤维处理方法能更有效地通过纳米材料桥在基体树脂和纤维增强材料之间更好地传递载荷。使用纳米材料定制尺寸和不使用催化剂的 CVD 工艺是将纳米材料固定在纤维上的最有效方法。这一进步为新一代可支持循环经济的可持续功能性聚合物复合材料奠定了基础。


Composites Science and Technology

Super-tough, super-elastic, temperature-responsive, and tunable viscoelastic elastomer enabled by embedding nanosized liquid metal droplets

Li Sai, Zhao Hengheng, Liu Minghui, Zeng Xiaofei, Wei Yuan, Zhang Ganggang, Liu Jun, Zhang Liqun

doi:10.1016/j.compscitech.2023.110311

 

通过嵌入纳米级液态金属液滴实现超强韧性、超强弹性、温度响应性和可调粘弹性弹性体

Liquid metal (LM) based composites are playing irreplaceable roles in many emerging fields such as stretchable and wearable electronics, soft robotics. However, it is still challenging to facilely fabricate the LM-based elastomers with nanosized and well-dispersed LM domains. Herein, the LM droplets filled elastomer nanocomposites (ENCs) with temperature-responsive, super-tough, super-elastic and tunable viscoelastic properties are introduced. By employing the conventional rubber processing method, LM is fragmented into nanoscale droplets and dispersed uniformly in cross-linked natural rubber (NR) without compromising the soft and highly stretchable properties of the matrix. In addition to the remarkable enhancement in tear resistance, the toughness of the resulting composites is strikingly improved as lowering the applied temperature, which is attributed to the phase transition and the simultaneous volume expansion of LM droplets. Surprisingly, for the viscoelasticity, this LM-based ENCs exhibit almost the same dynamic hysteresis with the pure NR system at the service condition of automobile tires, which is remarkably reduced compared to the traditional ENCs filled with rigid nanoparticles. Furthermore, this material also shows a good damping property for noise attenuation in the case of submarine covering. Collectively, this work opens a new avenue for the next generation of high-performance and multifunctional ENCs equipped in low-temperature working conditions.

基于液态金属(LM)的复合材料在许多新兴领域发挥着不可替代的作用,例如可拉伸和可穿戴电子设备、软机器人技术等。然而,如何方便地制造具有纳米尺寸和良好分散的液态金属畴的液态金属基弹性体仍是一项挑战。本文介绍了具有温度响应、超韧性、超弹性和可调粘弹性能的 LM 液滴填充弹性体纳米复合材料(ENCs)。通过采用传统的橡胶加工方法,LM 被破碎成纳米级液滴,并均匀地分散在交联天然橡胶(NR)中,而不会影响基体的柔软和高拉伸性能。除了抗撕裂性显著增强外,随着应用温度的降低,所得复合材料的韧性也显著提高,这归因于 LM 液滴的相变和同时的体积膨胀。令人惊讶的是,在粘弹性方面,这种基于 LM 的 ENC 在汽车轮胎的使用条件下表现出与纯 NR 系统几乎相同的动态滞后,与填充了刚性纳米颗粒的传统 ENC 相比明显减少。此外,这种材料还显示出良好的阻尼特性,可用于海底覆盖层的噪声衰减。总之,这项工作为在低温工作条件下装备下一代高性能、多功能 ENC 开辟了一条新途径。


来源:复合材料力学仿真Composites FEM
ACTAdditiveSystemMAGNET复合材料化学汽车电子UG材料机器人多尺度
著作权归作者所有,欢迎分享,未经许可,不得转载
首次发布时间:2024-11-03
最近编辑:26天前
Tansu
签名征集中
获赞 6粉丝 0文章 776课程 0
点赞
收藏
作者推荐

【新文速递】2023年10月13日复合材料SCI期刊最新文章

今日更新:Composite Structures 4 篇,Composites Part A: Applied Science and Manufacturing 5 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇Composite StructuresDamage and failure mechanisms of CFRP due to manufacturing induced wrinkling defectsChen Lixiao, Miao Lei, Xu Qiang, Yang Qiangxin, Zhu Weidong, Ke Yinglindoi:10.1016/j.compstruct.2023.117624因制造引起的皱褶缺陷导致的 CFRP 损坏和失效机制Out-of-plane wrinkling is a typical defect in the manufacturing process of carbon fiber reinforced plastics (CFRP). The cross-ply composite laminates containing various wrinkles were designed and prepared based on a hybrid generation method of gaps and transverse strips. An analytical model based on the sine function was proposed to characterize the shape of wrinkles, and the severity of the defect was characterized by the wrinkle angle. With the aim to investigate the compression and out-of-plane shear failure performance of CFRP with wrinkles, experimental and numerical studies were conducted. Results show that the existence of wrinkled zone can significantly reduce the compressive strength of laminates and exacerbate delamination during compression failure, a maximum of 26.9% and 2.8% drop in the compressive and interlaminar shear strength was reported in the most severe experimental conditions. Meanwhile, it is indicated that wrinkles have little effect on interlaminar shear strength, but it can change the location and severity of the delamination failure. In addition, the failure mechanism of several models with different levels of wrinkling defects was studied through numerical analysis techniques. It is confirmed that the numerical model can effectively predict the failure intensity and failure modes. These findings are of great significance for the accurate evaluation of the mechanical properties of composites containing wrinkling defects.平面外起皱是碳纤维增强塑料(CFRP)制造过程中的典型缺陷。基于间隙和横向条带的混合生成方法,设计并制备了含有各种褶皱的交叉层复合材料层压板。提出了一个基于正弦函数的分析模型来表征皱纹的形状,并通过皱纹角度来表征缺陷的严重程度。为了研究带皱纹的 CFRP 的压缩和平面外剪切破坏性能,进行了实验和数值研究。结果表明,皱褶区的存在会显著降低层压板的抗压强度,并加剧压缩破坏过程中的分层现象,在最严重的实验条件下,抗压强度和层间剪切强度的最大降幅分别为 26.9% 和 2.8%。同时,研究表明皱纹对层间剪切强度的影响很小,但会改变分层破坏的位置和严重程度。此外,还通过数值分析技术研究了几种具有不同程度褶皱缺陷的模型的破坏机理。结果表明,数值模型能有效预测破坏强度和破坏模式。这些发现对于准确评估含有起皱缺陷的复合材料的力学性能具有重要意义。Advanced lamination parameter interpolation and extrapolation methods for designing manufacturable variable stiffness laminatesShahabad Peiman Khandar, Anamagh Mirmeysam Rafiei, Serhat Gokhan, Basdogan Ipek, Bediz Bekirdoi:10.1016/j.compstruct.2023.117608设计可制造的可变刚度层压板的先进层压参数内插法和外推法The design of variable stiffness laminates requires efficient methodologies due to the increased number of optimization variables associated with curvilinear fiber paths. Here, this need is addressed by the development of two novel approaches: the lamination parameter extrapolation method (LPEM) and the relaxed lamination parameter interpolation method (RLPIM). These techniques build on the previously proposed lamination parameter interpolation method (LPIM), and collectively they form a spectrum of approaches that differ in optimization capacity, conservativeness regarding fiber curvature constraints, and computational cost. The resulting governing equations are solved using the spectral Chebyshev method to further improve the efficiency of the optimization process. The case studies demonstrate the effectiveness and unique properties of the developed algorithms.由于与曲线纤维路径相关的优化变量数量增加,变刚度层压板的设计需要高效的方法。为满足这一需求,我们开发了两种新方法:层压参数外推法(LPEM)和放松层压参数插值法(RLPIM)。这些技术以之前提出的层状参数插值法(LPIM)为基础,共同构成了一个方法谱系,在优化能力、纤维曲率约束的保守性和计算成本方面各不相同。为了进一步提高优化过程的效率,我们采用了切比雪夫光谱法来求解所得到的控制方程。案例研究证明了所开发算法的有效性和独特性。Graded infill lattice structures design based on the moving morphable component method and partitioned coordinate mapping techniqueXu Wu, Liu Chang, Guo Yilin, Du Zongliang, Zhang Weisheng, Guo Xudoi:10.1016/j.compstruct.2023.117613基于移动可变形构件法和分区坐标映射技术的分级填充网格结构设计This work presents a novel method for designing gradient-varying lattice structures based on explicit topology optimization. The proposed method employs a set of Moving Morphable Components (MMC) and NURBS-based partitioned coordinate mapping (PCM) functions to describe material distribution within the design domain and control points grid in the parametric space for local control of the lattice structure within each subdomain, thereby generating diverse microstructure topologies in different regions while being able to ensure clear structural boundaries and high-order smooth connections between adjacent microstructures. Since the optimization parameters include only the explicit geometric parameters of the components and the perturbation coefficients of the mapping function, the number of design variables is substantially smaller compared to existing algorithms. The proposed method can efficiently generate graded lattice structures for various loading conditions and graded-infill structures. Numerical results validate the effectiveness of the proposed method.本研究提出了一种基于显式拓扑优化的梯度变化晶格结构设计新方法。该方法利用一组移动可变形组件(MMC)和基于 NURBS 的分区坐标映射(PCM)函数来描述设计域内的材料分布,并利用参数空间中的控制点网格来对每个子域内的晶格结构进行局部控制,从而在不同区域生成多样化的微结构拓扑,同时能够确保结构边界清晰,相邻微结构之间具有高阶平滑连接。由于优化参数只包括组件的显式几何参数和映射函数的扰动系数,因此与现有算法相比,设计变量的数量大大减少。所提出的方法可以有效地生成各种加载条件下的分级晶格结构和分级填充结构。数值结果验证了所提方法的有效性。A Novel Auxetic 3D Lattice Structure for Enhancing Energy AbsorptionZhang Wenzheng, Yin Hanfeng, Wu Yongchen, Jin Qiduo, Wu Lijia, Wen Guilin, Liu Jie, Wu Xindoi:10.1016/j.compstruct.2023.117620用于增强能量吸收的新型辅助三维晶格结构The auxetic lattice structures usually have excellent energy absorption characteristics since their failed part can resist crushing loads continuously. However, their platform stress is relatively lower and shorter than some conventional energy-absorbing lattice structures. A novel kind of auxetic three-dimensional (3D) lattice structure is proposed to overcome their shortcoming and improve energy absorption capacity. The proposed lattice structure is named as re-entrant-TPMS hexagonal (RTH), which consists of triply periodic minimal surface (TPMS) and 3D truss-based re-entrant hexagonal (RH) structures. The finite element (FE) method is employed to analyze the crashworthiness and Poisson’s ratio of RTH lattice structures, and the accuracy of the FE models is validated by comparing the existing experimental and theoretical results of the two sub-structures, respectively. The effect of various structural parameters on the energy absorption and negative Poisson’s ratio (NPR) effect of the RTH lattice structure is investigated to select the structure with better mechanical performance. The mechanism studies confirm that the platform stress is higher and longer compared to the 3D RH lattice structure. The NPR effect is also essentially consistent and accompanied by a stable shrinkage deformation due to the synergistic effect among the sub-structures. The proposed RTH lattice structure has potential applications in the crashworthiness design of carrier equipment for resisting more complex impact loads.由于其失效部分可持续抵抗挤压载荷,因此辅助晶格结构通常具有出色的能量吸收特性。然而,与一些传统吸能晶格结构相比,它们的平台应力相对较低且较短。为了克服这些缺陷并提高能量吸收能力,我们提出了一种新型的辅助三维(3D)晶格结构。所提出的晶格结构被命名为再入-TPMS 六边形(RTH),它由三周期最小面(TPMS)和基于三维桁架的再入六边形(RH)结构组成。采用有限元(FE)方法分析了 RTH 晶格结构的耐撞性和泊松比,并分别通过比较两个子结构的现有实验和理论结果验证了 FE 模型的准确性。研究了各种结构参数对 RTH 网格结构能量吸收和负泊松比效应的影响,以选择力学性能更好的结构。机理研究证实,与三维 RH 晶格结构相比,平台应力更高、更长。由于子结构之间的协同效应,NPR效应也基本一致,并伴随着稳定的收缩变形。所提出的 RTH 晶格结构在载运设备的防撞设计中具有潜在的应用价值,可用于抵抗更复杂的冲击载荷。Composites Part A: Applied Science and ManufacturingRobust and Stretchable Ti3C2Tx MXene/PEI Conductive Composite Dual-Network Hydrogels for Ultrasensitive Strain SensingXie Jinliang, Su Fangfang, Fan Ling, Mu Zheshen, Wang Hongni, He Zhongjie, Zhang Weirui, Yao Dongdong, Zheng Yapingdoi:10.1016/j.compositesa.2023.107833 用于超灵敏应变传感的坚固且可拉伸的 Ti3C2Tx MXene/PEI 导电复合双网水凝胶The development of high-performance hydrogels with superior strength, stretchability, and conductivity is critical to the practical application of flexible sensors. In this study, we employed a strategy that involves introducing physical cross-linking points, creating a double network, and adding nanofillers. By utilizing a two-step method that involves thermal cross-linking and post-immersion cross-linking, and using two common metal ions to crosslink different polymer networks, we successfully developed a conductive composite dual-network hydrogel. In addition, the incorporation of modified MXene has significantly improved the strength and toughness of the hydrogel. The resulting hydrogel exhibits impressive mechanical properties, including a tensile strength of 2.64 MPa and elongation at break of 689%, as well as high toughness of 10.25 MJ·m−3 and conductivity of 1.89 S/m. When applied as a flexible sensor in electronic skin, the sensor demonstrates a wide operating range (>300%), high sensitivity (GF=4.64), and excellent linear detection ability (R2=0.99).开发具有卓越强度、拉伸性和导电性的高性能水凝胶对于柔性传感器的实际应用至关重要。在这项研究中,我们采用的策略包括引入物理交联点、创建双层网络和添加纳米填料。通过热交联和浸泡后交联两步法,并使用两种常见的金属离子交联不同的聚合物网络,我们成功地开发出了一种导电复合双网络水凝胶。此外,改性 MXene 的加入大大提高了水凝胶的强度和韧性。所制备的水凝胶具有令人印象深刻的机械性能,包括 2.64 兆帕的拉伸强度和 689% 的断裂伸长率,以及 10.25 兆焦耳/立方米的高韧性和 1.89 S/m 的导电率。该传感器作为柔性传感器应用于电子皮肤时,具有工作范围广(>300%)、灵敏度高(GF=4.64)和线性检测能力强(R2=0.99)等特点。Retaining High Fracture Toughness in Aged Polymer Composite/Adhesive Joints through Optimization of Plasma Surface TreatmentAliheidari Nahal, Ameli Amirdoi:10.1016/j.compositesa.2023.107835 通过优化等离子表面处理保持老化聚合物复合材料/粘合剂接头的高断裂韧性A response surface methodology was used to analyze the flow rate, power, and time factors of plasma surface treatment. Surface free energy (SFE) of treated glass fiber-reinforced composites showed a strong quadratic dependence on flow rate, power, and time, with significant interaction between time and power. Optimized factors predicted a maximum SFE of 78.63 mN/m, which matched well with the measured value of 77.42 mN/m, accounting for 2.46 times increase in SFE against untreated case. Moreover, with plasma treatment, the SFE’s polar component became dominant (99%) as also confirmed with FTIR spectroscopy. Fracture toughness testing of fresh and aged adhesive joints proved a more stable interface for plasma-treated specimens due to the covalent bonds facilitated by the functional groups formed during the treatment. Consequently, the fracture toughness of the plasma-treated specimens did not drop after seawater immersion, while that for the untreated and sand-treated specimens showed about a 15% drop.采用响应面方法分析了等离子表面处理的流速、功率和时间因素。经处理的玻璃纤维增强复合材料的表面自由能(SFE)与流速、功率和时间呈强烈的二次函数关系,时间与功率之间存在显著的交互作用。优化因子预测的最大表面自由能为 78.63 mN/m,与测量值 77.42 mN/m 非常吻合,与未处理情况相比,表面自由能增加了 2.46 倍。此外,经等离子处理后,SFE 的极性成分占主导地位(99%),傅立叶变换红外光谱也证实了这一点。新鲜和老化粘合剂接头的断裂韧性测试表明,经过等离子处理的试样界面更加稳定,这是因为在处理过程中形成的官能团促进了共价键的形成。因此,经过等离子处理的试样在海水浸泡后断裂韧性没有下降,而未经处理和砂处理的试样断裂韧性下降了约 15%。Cellulose nanofiber-introduced continuous-ramie yarn-reinforced polylactic acid filament for 3D printing: Novel fabrication process and mechanical propertiesMatumoto Koki, Takemura Kenichi, Kitamura Ryuta, Katogi Hideaki, Tanaka Tatsuya, Takagi Hitoshidoi:10.1016/j.compositesa.2023.107836用于 3D 打印的纤维素纳米纤维引入连续拉米纱增强聚乳酸长丝:新颖的制造工艺和机械性能This study focused on reinforcing the interface of continuous-ramie yarn-reinforced polylactic acid (PLA) filaments with cellulose nanofibers (CNFs) for 3D printing applications. To realize the reinforcement effect of CNFs, the distribution of dispersed CNFs at the surface of ramie fiber is necessary. Thus, we developed a new false-untwisting process to enable the continuous dip-coating of CNF slurry while the ramie yarn is untwisted yarn. This study was designed to reveal the influence of the false-untwisting process and CNF content on the surface morphology of the processed yarn and on the mechanical properties of the yarn–PLA composite filaments. We found that the false-untwisting process achieved the formation of fuzzy CNFs. Furthermore, the tensile strength and Young’s modulus of the filaments were improved by up to 20.0% and 26.6%, respectively, compared to those of ramie yarn-reinforced PLA filaments without CNFs.本研究的重点是用纤维素纳米纤维(CNFs)增强连续苎麻纱增强聚乳酸(PLA)长丝的界面,使其适用于 3D 打印应用。要实现 CNFs 的增强效果,必须在苎麻纤维表面分布分散的 CNFs。因此,我们开发了一种新的假解捻工艺,使 CNF 浆料在苎麻纱未解捻时能够连续浸涂。本研究旨在揭示假解捻工艺和 CNF 含量对加工后纱线表面形态以及纱线-聚乳酸复合丝机械性能的影响。我们发现假解捻工艺实现了模糊 CNF 的形成。此外,与不含 CNFs 的苎麻纱增强聚乳酸长丝相比,长丝的拉伸强度和杨氏模量分别提高了 20.0% 和 26.6%。A novel porous carbon synthesized to serve in the preparation of highly dense and high-strength SiC/SiC by reactive melt infiltrationGuo Guangda, Ye Fang, Cheng Laifei, Li Zhaochen, Zhang Litongdoi:10.1016/j.compositesa.2023.107839通过反应熔渗合成一种新型多孔碳,用于制备高密度、高强度 SiC/SiCSiC/SiC composites, prepared by reactive melt infiltration (RMI), exhibit exceptional properties. However, the presence of residual Si in the composite matrix can significantly compromise their high-temperature mechanical properties. Addressing the issue of high-content residual Si aggregation remains a crucial focus of research in order to fully unlock the application potential of SiC/SiC composites prepared by RMI. In this work, a special porous carbon (Cg) is successfully synthesized and introduced into the porous 2D SiC/SiC composites prepared by CVI. The unique pore structure of the SiC/SiC-Cg is thoroughly analyzed, along with its liquid Si infiltration process. The difference in coefficient of thermal expansion (CTE) between SiC and Cg can cause thermal stress, which can destory the Cg structure. Consequently, the C particles detach from the Cg skeleton and react with liquid Si to create SiC. This process effectively separates residual Si and helps alleviate the negative effects of residual Si aggregation. The microstructure and phase distribution of SiC/SiC composites obtained by liquid Si infiltrating different C structures are investigated and compared, and it demonstrates the positive effect of Cg on the uniform phase distribution of matrix in the composites. The as-received SiC/SiC composites possess a density of 2.94 g/cm3 with open porosity of 1.23%, and a flexural strength of 808.7±10.2MPa, a fracture toughness of 25.5±1.8MPa·m1/2, a tensile strength of 317.4±12.4MPa and a proportional ultimate stress of 157.33±4.1MPa. Acoustic emission (AE) and digital image correlation (DIC) technology are used to study the special mechanical behavior of composites.通过反应熔融渗透(RMI)制备的碳化硅/碳化硅复合材料具有优异的性能。然而,复合材料基体中残留硅的存在会严重影响其高温机械性能。为了充分释放 RMI 制备的 SiC/SiC 复合材料的应用潜力,解决高含量残留硅聚集问题仍然是研究的关键重点。本研究成功合成了一种特殊的多孔碳(Cg),并将其引入到 CVI 制备的多孔二维 SiC/SiC 复合材料中。该研究深入分析了 SiC/SiC-Cg 的独特孔隙结构及其液态硅渗透过程。SiC 和 Cg 之间的热膨胀系数 (CTE) 差异会产生热应力,从而破坏 Cg 结构。因此,C 颗粒会从 Cg 骨架中分离出来,并与液态 Si 反应生成 SiC。这一过程有效地分离了残留硅,有助于减轻残留硅聚集的负面影响。研究并比较了液态 Si 渗入不同 C 结构的 SiC/SiC 复合材料的微观结构和相分布,结果表明 Cg 对复合材料中基体相的均匀分布具有积极作用。所得 SiC/SiC 复合材料的密度为 2.94 g/cm3,孔隙率为 1.23%,弯曲强度为 808.7±10.2MPa,断裂韧性为 25.5±1.8MPa-m1/2,拉伸强度为 317.4±12.4MPa,比例极限应力为 157.33±4.1MPa。声发射(AE)和数字图像相关(DIC)技术用于研究复合材料的特殊力学行为。Characterization and Computational Modeling of Continuous-fiber Prepreg Ply-ply Interaction BehaviorYang Yunpei, Colton Jonathandoi:10.1016/j.compositesa.2023.107840连续纤维预浸料层间相互作用行为的表征和计算建模Ply-ply interaction behavior critically affects wrinkle formation during composite forming. This paper presents a computational model of the ply-ply interaction behavior of woven thermoset prepreg fabrics. The computational model includes visco-elastic, pressure-sensitive adhesion behavior, as well as a yield behavior that allows the deformation to transition from adhesion to friction. The model is based on the analysis and observations of double-lap shear factor effect screening tests and of total slip test measurements. To validate the computational model, finite element simulations are compared to experimental response surface tests for various pressures and deformation rates. The comparison shows that the computational model closely captures the load-deformation response of the ply-ply interaction. This computational model can be used in a forming process simulation to predict wrinkle formations.层间相互作用行为对复合材料成型过程中皱纹的形成有着至关重要的影响。本文介绍了热固性预浸料编织物层间相互作用行为的计算模型。该计算模型包括粘弹性、压敏粘附行为,以及允许变形从粘附过渡到摩擦的屈服行为。该模型基于对双圈剪切因子效应筛选试验和总滑移试验测量结果的分析和观察。为了验证计算模型,将有限元模拟与各种压力和变形率的响应面试验进行了比较。比较结果表明,计算模型紧密捕捉到了层间相互作用的载荷-变形响应。该计算模型可用于成型工艺模拟,以预测皱纹的形成。Composites Part B: EngineeringScalable high-performance wood-based composites prepared by hydro-mechanical treatmentHuang Yuxiang, Lin Qiuqin, Fu Feng, Lin Lanying, Yu Wenjidoi:10.1016/j.compositesb.2023.111041通过水力机械处理制备可扩展的高性能木基复合材料Developing an efficient, eco-friendly method for manufacturing structural biomaterials is crucial in fostering environmental sustainability. In this study, we introduced a hydro-mechanical pretreatment coupled with resin impregnation and hot pressing to create high-performance wood-based composites (WC) using rapidly growing natural wood. We conducted a thorough analysis to assess the impact of water content on the physical and chemical properties of natural wood, as well as the structural response of wood undergoing hydro-mechanical treatment. The results demonstrated that water significantly aids in transforming the weak-phase structure of wood, thereby preserving wood cell integrity to the maximum extent during subsequent mechanical dissociation processes. Due to the presence of retained cells and the distinctive three-dimensional bonding interface structure, the WC exhibited a bending strength of 231 MPa and a modulus of elasticity of 25 GPa, both surpassing those of natural wood by a factor of 2.1 and exceeding typical wood-based composites. Furthermore, WC exhibited minimal dimensional changes, with a mere 6.45 % increase in thickness and a 1.65 % increase in width following a 24-h hydrothermal treatment at 63 °C. Our approach to producing high-performance WC through a simple, entirely physical method utilizing rapidly growing natural wood holds great potential for advancing the development of a low-carbon, environmentally sustainable society.开发一种高效、环保的生物结构材料制造方法对于促进环境的可持续发展至关重要。在这项研究中,我们引入了水力机械预处理、树脂浸渍和热压工艺,利用快速生长的天然木材制造高性能木基复合材料(WC)。我们进行了全面分析,以评估含水量对天然木材物理和化学特性的影响,以及经过水力机械处理的木材的结构响应。结果表明,水能明显帮助改变木材的弱相结构,从而在随后的机械解离过程中最大程度地保持木材细胞的完整性。由于存在保留的细胞和独特的三维粘合界面结构,WC 的弯曲强度达到 231 兆帕,弹性模量达到 25 千兆帕,均超过天然木材 2.1 倍,也超过了典型的木基复合材料。此外,WC 的尺寸变化极小,在 63 °C 水热处理 24 小时后,厚度仅增加 6.45%,宽度仅增加 1.65%。我们利用快速生长的天然木材,通过一种简单、完全物理的方法生产出高性能的 WC,这种方法在推动低碳、环境可持续发展社会的发展方面具有巨大的潜力。Composites Science and TechnologyPredicting mechanical and electrical failure of nanowire networks in flexible transparent electrodesGrazioli Davide, Gangi Gabriele, Nicola Lucia, Simone Angelodoi:10.1016/j.compscitech.2023.110304 预测柔性透明电极中纳米线网络的机械和电气故障Flexible transparent electrodes employing metal nanowires (NWs) find extensive use in various applications such as optoelectronic devices, solar cells, light-emitting diodes, and transparent heaters. NW networks in metal electrodes can withstand mechanical deformations and conduct electricity but are susceptible to localized damage caused by mechanical stress and current density concentration. This localized damage ultimately results in electrode failure. Our study aims to track locally induced damage from both mechanical and electrical sources and assess their collective influence on electrode performance until failure occurs. To this end, we create two-dimensional digital samples that represent the NW networks, transform them into beam networks and equivalent resistor networks, and perform finite element simulations of the mechanical and electrical network responses while varying the NW content. Our simulations reveal crack-like patterns in the distribution of damaged elements at network failure that depend on the process inducing the damage. While our results suggest that the impact of electrically induced damage on overall network stability is more significant than that of mechanically induced damage, the latter must not be ignored.采用金属纳米线(NWs)的柔性透明电极在光电设备、太阳能电池、发光二极管和透明加热器等各种应用中得到广泛应用。金属电极中的纳米线网络可以承受机械变形并导电,但容易受到机械应力和电流密度集中造成的局部损坏。这种局部损伤最终会导致电极失效。我们的研究旨在跟踪来自机械和电气源的局部损伤,并评估它们对电极性能的共同影响,直至发生失效。为此,我们创建了代表 NW 网络的二维数字样本,将其转换为梁网络和等效电阻网络,并在改变 NW 含量的同时对机械和电气网络响应进行有限元模拟。我们的模拟结果表明,在网络失效时,受损元件的分布会出现类似裂纹的模式,而这种模式取决于诱发损坏的过程。虽然我们的结果表明,电诱导损伤对整体网络稳定性的影响比机械诱导损伤更为显著,但后者也不容忽视。来源:复合材料力学仿真Composites FEM

未登录
还没有评论
课程
培训
服务
行家
VIP会员 学习 福利任务 兑换礼品
下载APP
联系我们
帮助与反馈