今日更新:Composite Structures 1 篇,Composites Science and Technology 2 篇
Finite Element Method with 3D Polyhedron-Octree for the Analysis of Heat Conduction and Thermal Stresses in Composite Materials
Wang Lihui, Zhang Rui, Guo Ran, Liu Guangying
doi:10.1016/j.compstruct.2023.117649
用三维多面体-八叉树有限元法分析复合材料的热传导和热应力
Applying the hybrid flux finite element method(HF-FEM) and hybrid thermal stress finite element method (HTS-FEM) is not prevalent in analyzing heat conduction and thermal stresses in particle-reinforced composite materials. Most of the research on this technique is confined to two-dimensional problems. This paper proposes the HF-FEM and HTS-FEM, based on 3D polyhedron-octree, to calculate the steady-state heat conduction and thermal stress of particle-reinforced composites. In addition, this paper presents a method for partitioning spherical particle-reinforced materials into polyhedron-octree elements, each of which contains only one type of material. Each element is divided into multiple Delaunay tetrahedrons, and hammer integration is used to perform the integrals. Additionally, this paper presents a technique to construct the heat flux function for polyhedral elements, and the effectiveness of the above methods is demonstrated by comparing it to several numerical examples of traditional finite element methods.
在分析颗粒增强复合材料的热传导和热应力时,混合通量有限元法(HF-FEM)和混合热应力有限元法(HTS-FEM)的应用并不普遍。对这一技术的研究大多局限于二维问题。本文提出了基于三维多面体八叉树的 HF-FEM 和 HTS-FEM,用于计算颗粒增强复合材料的稳态热传导和热应力。此外,本文还提出了一种将球形颗粒增强材料划分为多面体-八叉树元素的方法,每个元素只包含一种材料。每个元素被划分为多个 Delaunay 四面体,并使用锤式积分法进行积分。此外,本文还介绍了一种构建多面体元素热通量函数的技术,并通过与几个传统有限元方法的数值实例进行比较,证明了上述方法的有效性。
Structural composite batteries made from carbon fibre reinforced electrodes / polymer gel electrolyte prepregs
Jiang Qixiang, Beutl Alexander, Kühnelt Helmut, Bismarck Alexander
doi:10.1016/j.compscitech.2023.110312
由碳纤维增强电极/聚合物凝胶电解质预浸料制成的结构复合电池
Full cells of structural composite batteries comprising carbon fibre reinforced anodes and cathodes decorated with lithium titanate and LiNi0.3Mn0.3Co0.3O2 (NMC111), respectively, embedded in a polymer gel electrolyte were produced. Spread carbon fibres were coated with cathode and anode active materials followed by impregnation with a polymer gel electrolyte consisting of PVDF particles dispersed in an ionic liquid containing a lithium salt. The resulting carbon fibre reinforced electrodes/polymer gel electrolyte prepregs could be easily stored, handled or, if needed, transported. Cathode and anode prepregs were laminated and fused by compression moulding, resulting within a time frame of couple of minutes in full cell structural composite batteries. The batteries were charged and discharged at current densities of 0.1C, resulting in a specific capacity of 35 mAh/gNMC111 and energy density of 5.6 Wh/(kg battery). The composite batteries had a Young's modulus of 4.6 GPa and tensile strength of 32 MPa. A facile layup process enabled proof-of-concept demonstration of ‘all’ carbon fibre full cell multifunctional structural composite batteries.
生产出了全电池结构复合材料电池,包括碳纤维增强阳极和阴极,分别用钛酸锂和 LiNi0.3Mn0.3Co0.3O2 (NMC111)装饰,并嵌入聚合物凝胶电解液中。在展平的碳纤维上涂覆阴极和阳极活性材料,然后浸渍聚合物凝胶电解质,聚合物凝胶电解质由分散在含锂盐离子液体中的 PVDF 颗粒组成。这样制成的碳纤维增强电极/聚合物凝胶电解质预浸料可以方便地储存、处理或在需要时运输。阴极和阳极预浸料通过压缩成型进行层压和熔合,在几分钟内就能制成全电池结构复合电池。电池在 0.1C 的电流密度下充放电,比容量为 35 mAh/gNMC111,能量密度为 5.6 Wh/(千克电池)。复合电池的杨氏模量为 4.6 GPa,抗拉强度为 32 MPa。简易铺层工艺实现了 "全 "碳纤维全电池多功能结构复合电池的概念验证。
Manufacturing carbon fabric composite structural batteries using spray with high-pressure and high-temperature and vacuum-bag assisted infusion techniques
Han Zhibin, Zhu Jianjian, Feng Yuncong, Zhang Wanrui, Xiong Yifeng, Zhang Weizhao
doi:10.1016/j.compscitech.2023.110321
利用高压高温喷射和真空袋辅助灌注技术制造碳纤维复合材料结构电池
This paper introduces a strategy for manufacturing composite structural batteries, integrating the dual roles of energy storage and load-bearing functionality. In the manufacturing process, both cathodes and anodes were produced by coating electrode materials on woven carbon fabrics via high-pressure and high-temperature spray method. A modified vacuum-bag assisted technique was employed to infuse electrolytes and assemble entire battery cells. Scanning electron microscopy was utilized to observe that the active electrode particles were effectively dispersed throughout the woven carbon fabrics. Electrochemical characterization demonstrated that the fabricated batteries could achieve a high energy density of 34.12 Wh/kg with benign rate performance and high Coulombic efficiency. Meanwhile, uniaxial tensile tests illustrated that the structural batteries had an ultimate tensile strength of 118.70 MPa and Young's modulus of 13.07 GPa along the yarn direction. Bias-extension experiments indicated that the shear modulus and yield strength were 2.87 GPa and 20.82 MPa, respectively. These results suggest that the multifunctional efficiency of the manufactured structural batteries was over 1, validating the effectiveness of the proposed manufacturing approach for composite structural batteries.
本文介绍了一种兼具储能和承重双重功能的复合结构电池制造策略。在制造过程中,阴极和阳极都是通过高压高温喷涂法将电极材料涂覆在碳纤维编织物上制成的。采用改进的真空袋辅助技术注入电解质并组装整个电池单元。利用扫描电子显微镜观察到活性电极颗粒有效地分散在碳纤维编织物上。电化学表征结果表明,所制造的电池可达到 34.12 Wh/kg 的高能量密度,并具有良好的速率性能和较高的库仑效率。同时,单轴拉伸试验表明,结构电池沿纱线方向的极限拉伸强度为 118.70 MPa,杨氏模量为 13.07 GPa。偏伸实验表明,剪切模量和屈服强度分别为 2.87 GPa 和 20.82 MPa。这些结果表明,所制造的结构电池的多功能效率超过了 1,验证了所提出的复合结构电池制造方法的有效性。