【新文速递】2024年9月29日固体力学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 1 篇，Composites Science and Technology 3 篇Composite StructuresClosed-form analytical solution for local buckling of omega-stringer-stiffened composite panels under compressionCherine El Yaakoubi-Mesbah, Christian Mittelstedtdoi:10.1016/j.compstruct.2024.118716受压下欧米茄筋加筋复合材料板局部屈曲的闭型解析解The use of stiffened thin-walled lightweight structures in e.g. aircraft fuselages requires efficient calculation methods to describe the stability behavior. In this work, a closed-form model for the local buckling analysis of orthotropic composite plates braced by omega-stringers is developed. The problem can be reduced to a plate simply supported at all edges subjected to uniaxial compression with eccentrically attached stringer feet, while the stringer itself is modeled as restraint stiffnesses along the longitudinal edges. The discontinuities in the stiffnesses introduced by the stringer feet result in discontinuities in the curvature behavior and the shear distortion of the structure. In order to map this influence on the local buckling behavior, the reduced model is divided into plate segments of corresponding stiffnesses, for which Ritz-based approach functions for the deformations are defined. Finally, an explicit formulation of the buckling load is derived using the energy method. To validate the model, the Lévy solution is obtained and a finite element analysis is conducted. The results of the parameter studies demonstrate excellent agreement within the design space of the aviation application area.在诸如飞机机身中使用加筋薄壁轻质结构需要有效的计算方法来描述其稳定性行为。本文建立了正交各向异性欧米茄筋支撑复合材料板局部屈曲分析的封闭模型。该问题可以简化为在单轴压缩下所有边缘都有简单支撑的板，并带有偏心附加的弦脚，而弦本身则被建模为沿纵向边缘的约束刚度。弦脚引入的刚度的不连续导致结构的曲率行为和剪切变形的不连续。为了映射这种对局部屈曲行为的影响，将简化模型划分为相应刚度的板段，并定义了基于ritz的变形逼近函数。最后，利用能量法推导出屈曲载荷的显式表达式。为了验证模型的正确性，得到了lsamvy解，并进行了有限元分析。参数研究的结果表明，在航空应用领域的设计空间内，参数研究的结果非常一致。Composites Part A: Applied Science and ManufacturingNonlinear transient analysis of delaminated composite shell panel under hygro-thermo-mechanical load and experimental validationChetan Kumar Hirwani, Naveen Kumar Akkasali, Erukala Kalyan Kumar, Ravi Kumar, Amit Kumar Mehar, Subrata Kumar Pandadoi:10.1016/j.compositesa.2024.108587湿热机械载荷作用下分层复合材料壳板非线性瞬态分析及实验验证In this work, the nonlinear time-dependent deflection responses of delaminated composite shell panel structure under the influence of hygro-thermo-mechanical loading have been investigated numerically. To develop a mathematical model, two different higher-order displacement kinematics, Green-Lagrange’s nonlinear strain–displacement relations and two sub-laminate approaches are adopted for delaminated panel structure in association with finite element steps. The delaminated composite shell panel is under the three simultaneous loading, i.e., humidity, temperature, and mechanical loading. The nonlinear time-dependent responses are obtained by solving the governing equation using the direct iterative method and Newmark’s integration technique. The influence of delamination parameters (size, location, and position), geometry and loading on dynamic characteristics have been analyzed. The differences in responses indicated that the kinematic model with higher degrees of freedom generally shows higher deflection values. Further, a detailed discussion of the numerical illustrations and conclusive remarks based on the findings of the numerical illustrations have been provided.本文对分层复合材料壳板结构在湿热机械载荷作用下的非线性时变挠度响应进行了数值研究。为了建立数学模型，采用格林-拉格朗日非线性应变-位移关系和两种不同的高阶位移运动学方法，结合有限元步骤对分层板结构进行分层。分层复合壳板同时承受湿度、温度和机械三种载荷。采用直接迭代法和Newmark积分法求解控制方程，得到非线性时变响应。分析了分层参数（尺寸、位置和位置）、几何形状和载荷对动态特性的影响。响应的差异表明，自由度越大的运动学模型通常具有较高的挠度值。此外，还提供了数值图解的详细讨论和基于数值图解结果的结论性评论。Composites Part B: EngineeringN/S co-doped nanocomposite of graphene oxide and graphene-like organic molecules as all-carbonaceous anode material for high-performance Li-ion batteriesWooree Jang, Jongmin Kim, Seoyun Lee, Seokhoon Ahn, Hyeyoung Koo, Cheol-Min Yangdoi:10.1016/j.compositesb.2024.111994 N/S共掺杂氧化石墨烯与类石墨烯有机分子纳米复合材料作为高性能锂离子电池的全碳阳极材料In this study, to enhance the electrochemical performance of graphene-based anodes for Li-ion batteries (LIBs), we synthesized an all-carbonaceous N/S co-doped nanocomposite of graphene oxide (GO) and graphene-like small organic molecules (GOM) using a mild, eco-friendly, one-step hydrothermal method with thiourea (CH4N2S) (denoted as h-N/S-GO/GOM). The thiourea facilitated N/S co-doping and π−π bonding, which improved the interaction between hydrophilic GO and hydrophobic GOM in aqueous solution. Notably, the formation of π−π bonds between GO and GOM created pathways that enhanced electron transfer, thereby promoting efficient Li-ion transport from the electrolyte through the channels during rapid charge–discharge cycles. Additionally, the functional groups resulting from N/S co-doping increased the number of active sites within the nanocomposite. Consequently, the h-N/S-GO/GOM anode demonstrated superior electrochemical performance, achieving an average reversible capacity of 1265 mAh g−1 at 0.1 A g−1 and retaining 83.0% of its capacity after 200 cycles. Furthermore, the nanocomposite exhibited excellent long-term cycling stability, maintaining a capacity of 688 mAh g−1 even after 1000 cycles at a high current density of 1.0 A g−1. The hierarchical network structure of the all-carbonaceous h-N/S-GO/GOM anode facilitated efficient charge transfer between the electrode and electrolyte through shorter diffusion paths for Li-ion transport and provided additional active sites, contributing to its outstanding electrical performance. The h-N/S-GO/GOM nanocomposite represents a promising alternative to traditional graphite-based anodes, offering a path toward high-performance, eco-friendly LIBs suitable for applications such as electric vehicles and energy storage systems.在本研究中，为了提高锂离子电池（LIBs）石墨烯基阳极的电化学性能，我们采用温和、环保的一步水热法与硫脲（CH4N2S）合成了氧化石墨烯（GO）和类石墨烯小有机分子（GOM）的全碳共掺杂纳米复合材料（记为h-N/S-GO/GOM）。硫脲促进了N/S共掺杂和π−π成键，改善了水溶液中亲水性GO和疏水性GOM之间的相互作用。值得注意的是，GO和GOM之间π−π键的形成创造了增强电子转移的途径，从而促进了锂离子在快速充放电循环中从电解质通过通道的高效传输。此外，由N/S共掺杂产生的官能团增加了纳米复合材料中活性位点的数量。结果表明，h-N/S-GO/GOM阳极表现出优异的电化学性能，在0.1 A g−1时平均可逆容量达到1265 mAh g−1，并且在200次循环后保持83.0%的容量。此外，该纳米复合材料表现出优异的长期循环稳定性，在1.0 a g−1的高电流密度下，即使在1000次循环后，其容量仍保持在688 mAh g−1。全碳h-N/S-GO/GOM阳极的分层网络结构通过更短的锂离子传输扩散路径，促进了电极和电解质之间有效的电荷转移，并提供了额外的活性位点，有助于其出色的电学性能。h-N/S-GO/GOM纳米复合材料代表了传统石墨基阳极的一个有前途的替代品，为高性能、环保的锂离子电池提供了一条道路，适用于电动汽车和储能系统等应用。Composites Science and TechnologySulfur Co-polymer as a Universal Adhesive to Construct Segregated Structure in Cross-linked Rubber toward Improved Conductive and Mechanical PropertiesShu Wang, Zhenghai Tang, Yilin Xiao, Dong Wang, Baochun Guo, Liqun Zhangdoi:10.1016/j.compscitech.2024.110964 硫共聚物作为一种通用胶粘剂在交联橡胶中构建分离结构以改善导电性能和力学性能Creating segregated structure within composites can significantly improve electrical conductivity but usually compromises mechanical properties. In this contribution, we introduced a straightforward and universal method to fabricate segregated rubber composites with a rare integration of high electrical conductivity and mechanical robustness by utilizing an inverse vulcanized copolymer (SP) as an adhesive to bind the segregated domains. Specifically, sulfur-crosslinked butadiene styrene rubber (SBR) granules were mixed with SP and carbon nanotubes (CNTs), followed by compression molding. CNTs embedded within SP are strategically dispersed along the boundaries of SBR granules, and the reaction of SP with SBR granules creates covalent bonding among the segregated domains and increases their crosslinking density. The segregated skeleton constituted by highly interconnected CNTs is robust, which imparts the composites with high electrical conductivity that is stable upon deformations and is able to heal after damage. In addition, the rigid segregated skeleton preferentially ruptures to dissipate enormous energy, and the cohesive interphase facilitates chain finite extensibility in the highly crosslinked segregated domains, resulting in remarkable enhancements on the tensile strength and modulus of the composites. The universality of this strategy is further demonstrated by using ground waste tyre rubber as matrix and boron nitride sheets as filler.在复合材料中创建分离结构可以显著提高导电性，但通常会损害机械性能。在这篇文章中，我们介绍了一种简单而通用的方法来制造分离橡胶复合材料，通过利用反硫化共聚物（SP）作为粘合剂来结合分离域，该方法具有高导电性和机械稳健性的罕见集成。具体来说，将硫交联丁苯橡胶（SBR）颗粒与SP和碳纳米管（CNTs）混合，然后进行压缩成型。嵌入SP中的CNTs沿着SBR颗粒的边界有策略地分散，SP与SBR颗粒的反应在分离的结构域之间形成共价键，增加了它们的交联密度。由高度互联的CNTs构成的分离骨架是坚固的，这使得复合材料具有高导电性，在变形时稳定，在损伤后能够自愈。此外，刚性偏析骨架优先断裂以耗散大量能量，而内聚界面在高度交联的偏析畴中促进了链的有限扩展，从而显著提高了复合材料的抗拉强度和模量。以磨碎的废轮胎橡胶为基体，氮化硼片为填料，进一步证明了该策略的普遍性。Vertically Aligned Liquid Metal Thermal Pad with Excellent Electromagnetic Shielding and Ultra-High CompressibilityYisimayili Tuersun, Pingjun Luo, Xu Huang, Mingdeng Huang, Yilimiranmu Rouzhahong, Chu Shengdoi:10.1016/j.compscitech.2024.110974 具有优异电磁屏蔽和超高压缩性的垂直排列液态金属热垫With the increasing integration level of modern electronics, flexible highly thermally conductive and electromagnetic interference shielding (EMI) materials were urgently demanded in electronic devices. Traditionally carbon or solid metal fillers are widely used as a reinforcement to fabricate a flexible thermally conductive and EMI shielding materials. However Due to the trade-off between mechanical and thermal properties, it is difficult to further improve the performance of solid filler/polymer composites. Here in this work based on the intrinsic excellent electrical and thermal conductivity of liquid metal (LM), we embedded the LM network structure vertically in the silicone gel and fabricated a vertically aligned LM(VALM) composites. Compared to the randomly dispersed LM composites, VALM composite exhibits high through plane thermal conductivity (κ⊥: 6.08 W/m·K) and excellent EMI shielding efficiency (SE) (minimum and maximum EMI SE for VALM2 were 33.2 dB and 39.5 dB). In addition, due to the fluidic nature of LM, composite materials exhibit excellent softness and flexibility (compression modulus of 0.56 MPa). Practical heat dissipation test results and EMIS efficiencies demonstrate usefulness of VALM composite in next-generation electronics.随着现代电子产品集成化水平的不断提高，柔性高导热和电磁干扰屏蔽材料在电子器件中的应用日益迫切。传统上，碳或固体金属填料被广泛用作增强材料来制造柔性导热和电磁干扰屏蔽材料。然而，由于力学性能和热性能之间的权衡，固体填料/聚合物复合材料的性能很难进一步提高。本文基于液态金属（LM）固有的优异的导电性和导热性，将液态金属网络结构垂直嵌入有机硅凝胶中，制备了垂直排列的液态金属（VALM）复合材料。与随机分散的LM复合材料相比，VALM复合材料具有高透平面导热系数（κ⊥:6.08 W/m·K）和优异的EMI屏蔽效率（SE） （VALM2的最小和最大EMI SE分别为33.2 dB和39.5 dB）。此外，由于LM的流体性质，复合材料表现出优异的柔软性和柔韧性（压缩模量为0.56 MPa）。实际的散热测试结果和EMIS效率证明了VALM复合材料在下一代电子产品中的实用性。3D printing lignin carbonized nanotube and cellulose nano fiber aerogel for wearable pressure sensorsXiaoqing Du, Qi Chen, Qiqi Zhou, Yufan Zhou, Feng Wang, Wangjie Xu, Yulin Zhan, Man Jiangdoi:10.1016/j.compscitech.2024.110976 3D打印木质素碳化纳米管和纤维素纳米纤维气凝胶用于可穿戴压力传感器The nanocellulose represents an important sustainability and chemical stability candidate for conductive 3D aerogel sensors, while introducing additional conductive additives is necessary. Herein, the as developed lignin derived carbonized nanotube (LCNT) in our lab was adopted as conductive ingredient to fabricate cellulose nanofiber (CNF) based composite aerogel by 3D printing. Specifically, the as-prepared LCNT/CNF composite aerogel with ratio of 85:15 in weight presented homogeneous porous morphology with well dispersed and penetrated LCNT in CNF porous matrix, providing a piezoresistive type pressure sensor. Stable signals were achieved under testing range from 0.2 to 9.8 kPa, with response time between 100-200 ms, related to the testing accuracy. The mechanical property of the as-prepared composite aerogel was found to be satisfactory. Under a constant 30% compression strain for 1000 cycles, 92.5% stress retention was maintained, and the ultimate stress was tested to be 16.64 kPa. This work provided a customized wearable pressure sensor with satisfactory comprehensive performance made completely from cellulose and lignin renewable natural polymers.纳米纤维素代表了导电3D气凝胶传感器的重要可持续性和化学稳定性候选材料，同时引入额外的导电添加剂是必要的。本课题以本实验室开发的木质素衍生碳化纳米管（LCNT）为导电材料，采用3D打印技术制备纤维素纳米纤维（CNF）基复合气凝胶。具体而言，制备的重量比为85:15的LCNT/CNF复合气凝胶具有均匀的多孔形态，LCNT在CNF多孔基质中分散和渗透良好，可提供压阻式压力传感器。在0.2 ~ 9.8 kPa的测试范围内获得了稳定的信号，响应时间在100 ~ 200 ms之间，与测试精度有关。所制备的复合气凝胶的力学性能令人满意。在30%恒定压缩应变下，循环1000次，其应力保持率为92.5%，极限应力为16.64 kPa。本工作提供了一种完全由纤维素和木质素可再生天然聚合物制成的具有满意综合性能的定制可穿戴压力传感器。来源：复合材料力学仿真Composites FEM