今日更新：Composite Structures 2 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 6 篇，Composites Science and Technology 1 篇
Composite Structures
A simple recovery post-processing of stresses and displacements in Reissner–Mindlin analysis of anisotropic laminated plates
P.T.R. Mendonça, W.R. de Lemos
doi:10.1016/j.compstruct.2024.117894
各向异性层状板 Reissner-Mindlin 分析中应力和位移的简单恢复后处理方法
The bending problem of anisotropic laminated plates is considered, modeled with first order shear deformation (FSDT) kinematic model and approximations obtained from the Generalized Finite Element Method (GFEM/ XFEM). A procedure is developed to recover the transverse normal and shear stresses and all displacement components, with improved variations across the laminate thickness, generating a complete three-dimensional approximate solution of the problem. The procedure starts with the results issuing from direct computations of in-plane stresses and displacements obtained by the 2D kinematic and constitutive equations. The recovered fields are obtained to, approximately, enforce local equilibrium, constitutive and strain–displacement equations in their three-dimensional forms, and interlaminar continuity. The general procedure considers inertia forces and von Kármán non-linearity. Corrections are made to impose the necessary 3D boundary conditions in both faces of the laminate. The easy way the GFEM admits basis function enrichment, whether by singular, discontinuous or by higher order p-enrichment, on a fixed mesh, makes the entire recovery procedure straightforward and non-iterative. The recovered fields accuracy is demonstrated in standard problems against exact solutions from three-dimensional elasticity and FEM reference approximations. Up to the author’s knowledge, the presented strategy is novel in the published literature of non-iterative post-processing methods. It provides a simple mean to obtain all stress and displacement component approximations necessary to application in many complete 3D local failure theories.
研究考虑了各向异性层压板的弯曲问题，采用一阶剪切变形（FSDT）运动学模型和广义有限元法（GFEM/ XFEM）获得的近似值进行建模。我们开发了一种程序来恢复横向法向应力和剪切应力以及所有位移分量，并改进了层压板厚度的变化，从而生成了问题的完整三维近似解。该程序以直接计算平面内应力和位移的结果为起点，通过二维运动学和构成方程获得。得到的恢复场可以近似执行局部平衡、三维形式的构成方程和应变-位移方程以及层间连续性。一般程序考虑了惯性力和 von Kármán 非线性。在层压板的两个面上施加必要的三维边界条件时会进行修正。GFEM 允许在固定网格上通过奇异、不连续或高阶 p 富集等方式进行基函数富集，这种简便的方式使得整个恢复过程简单明了且无需迭代。根据三维弹性和有限元参考近似的精确解，在标准问题中证明了恢复的场精确度。据作者所知，所提出的策略在已发表的非迭代后处理方法文献中是新颖的。它提供了一种简单的方法来获得所有应力和位移分量近似值，这些近似值是应用于许多完整的三维局部破坏理论所必需的。
Nonlinear Dynamics of Graphene-Reinforced Aluminum Matrix Composite Aero-Engine Blade in Thermal Environment
D.H. Huang, W. Zhang, Y.F. Zhang, A. Amer
doi:10.1016/j.compstruct.2024.117900
热环境下石墨烯增强铝基复合材料航空发动机叶片的非线性动力学特性
This paper analyzes the nonlinear dynamic behaviors of the graphene-reinforced aluminum-based aero-engine blade under the primary resonance using the amplitude-frequency response curves, bifurcation diagram, Lyapunov exponent and Poincaré map. The lateral aerodynamic load, longitudinal aerodynamic load, centrifugal force and temperature are investigated for the graphene-reinforced aluminum-based aero-engine blade. Three kinds of configurations for the functionally graphene-reinforced gradient are considered. The effective Young's modulus of the composite material is given by Halpin-Tsai mode. The rule of the mixture gives other material properties. The results demonstrate that the bifurcation diagrams of the modal amplitude for the blade with the lateral aerodynamic load, longitudinal aerodynamic load and temperature have the periodic-chaos dynamic evolution process under the disturbance of the engine rotation speed. When the disturbance amplitude reaches a specific value, a new round of the periodic-chaos dynamic evolution will be continued. The results also clearly indicate that the aero-engine blade has the rich and complex nonlinear dynamic behaviors which include the hyperchaos, chaos, almost periodic, typical period-doubling bifurcation and anti-period-doubling bifurcation vibrations. This research is more helpful for the engineers to understand the nonlinear dynamic behavior of the blade.
Composites Part A: Applied Science and Manufacturing
Numerical simulation at the micro-scale for the heat transfer modeling in the thermoplastic composites laser-assisted AFP process
Adrien Le Reun, Violaine Le Louët, Steven Le Corre, Vincent Sobotka
doi:10.1016/j.compositesa.2024.108010
用于热塑性复合材料激光辅助 AFP 工艺传热建模的微尺度数值模拟
Laser-assisted Automated Fibre Placement for thermoplastic composites has shown its potential to process complex shaped parts with high productivity rates but many challenges, both physical and technical, still need to be adressed in order to achieve proper in-situ consolidation. Ensuring high quality bonding of the laid tapes relies on perfect control of their thermal history throughout the process, and heat transfer has long proven essential to achieve this. Numerous heat transfer models account for optical interaction between the laser and composite at a macroscopic scale. Here, a thermo-optical model at the micro-scale is designed and differentiates the fibres from matrix domain, accounting for their respective properties. A single tape is modeled in a static configuration. Based on a composite material realistic microstructure, a ray-tracing algorithm highlights the laser heat absorption depth dependency to laser incidence angle and fibre distribution. Numerical surface temperatures are compared to experimental data obtained with a specific set-up leading to an overall accurate approximation. Finally, the microstructure model relevance is assessed with 1D homogenised models considering either ideal surface heating or a volumetric heat source. The surface heating model leads to inaccurate approximation of surface temperatures, whereas volumetric heat source absorption substantially limits temperature errors. As a result, this model gives a satisfactory compromise between model complexity, computational time and temperature prediction.
Effects of hexagonal boron nitride content on forming quality and performance of laser powder bed fusion manufactured nickel-based hastelloy X composites
Regulating the composition of nickel-based composites, especially those containing crack-sensitive Hastelloy X (HX) matrix, significantly influences the forming quality and performance of parts manufactured using laser powder bed fusion (LPBF). Ray tracing and temperature field simulations were conducted to analyze the non-equilibrium solidification mechanism of the laser processed hexagonal boron nitride (h-BN)-HX system, resulting in an optimized h-BN content range. The optimized composition, with 0.2 wt.% h-BN in HX, showcased the best forming quality and performance. It displayed negligible cracks or unmelted particles, minimal surface roughness of 9.29 μm, and superior tensile properties with a tensile strength of 1246.49 MPa and an elongation of 18.67 %. Furthermore, the samples showcased increased hardness (371.21 HV5) and reduced friction coefficient (0.54). Interestingly, with a further increase in h-BN content, a gradual improvement in strength and hardness was observed, accompanied by a reduction in the friction coefficient. Nevertheless, the ductility of the samples noticeably decreased. The 1 wt.% h-BN/HX sample exhibited a tensile strength of 1503.14 MPa, hardness of 502.13 HV5, and friction coefficient of 0.48 while displaying an elongation of only 3.76 %. These findings emphasize the significance of optimizing the composition of Ni-based composites to enhance the forming quality and performance of parts manufactured through LPBF, particularly in aerospace and engineering applications.
Postoperative bone regeneration repair for primary or metastatic bone tumors is often impeded by the adverse effects of chemotherapy treatment. As a low-toxicity therapeutic ion, the efficacy of Zn ions in promoting anti-tumor and bone regeneration outcomes has been demonstrated. However, the potential benefits are limited due to inadequate zinc intake in malignant cells and its anti-tumor mechanism remain unclear. Overcoming these difficulties, we report a new strategy for improving the delivery of Zn ions and antitumor drug by fabricating chitosan (CS) cryogel microspheres to synchronize the loading of resveratrol (Res) and Zn-BG. The Zn ions released from Zn-BG were combined with Res, then transported and enriched intracellularly, inducing apoptosis of tumor cells via multiple pathways. Moreover, the Zn-BG@Res-CS cryogel microspheres exhibited antibacterial and osteogenic effects. In particular, we found that this delivery system significantly inhibited tumor development and metastasis in vivo. Our founding suggests that the combination of Zn ions with Res could enhance cell uptake of Zn ions then induce apoptosis of tumor cells selectively. This study indicates that the combination chemotherapy and biomaterial construction could be a potential therapeutic approach for postoperative regeneration of bone tumor defects.
原发性或转移性骨肿瘤术后的骨再生修复往往受到化疗不良反应的阻碍。作为一种低毒性治疗离子，锌离子在促进抗肿瘤和骨再生方面的疗效已得到证实。然而，由于恶性细胞对锌的摄入不足，其潜在益处受到限制，而且其抗肿瘤机制仍不清楚。为了克服这些困难，我们报告了一种改进锌离子和抗肿瘤药物递送的新策略，即通过制造壳聚糖（CS）低温凝胶微球来同步负载白藜芦醇（Res）和锌-BG。Zn-BG释放的Zn离子与Res结合后在细胞内富集运输，通过多种途径诱导肿瘤细胞凋亡。此外，Zn-BG@Res-CS 低温凝胶微球还具有抗菌和成骨作用。特别是，我们发现这种递送系统能显著抑制体内肿瘤的发展和转移。我们的研究结果表明，锌离子与 Res 的结合可以增强细胞对锌离子的吸收，从而有选择性地诱导肿瘤细胞凋亡。这项研究表明，化疗与生物材料构建相结合可能是骨肿瘤缺损术后再生的一种潜在治疗方法。
Concurrently achieving strength-ductility combination and robust anti-wear performance in an in-situ high-entropy bulk metallic glass composite
Yin Du, Dongpeng Hua, Qing Zhou, Xuhui Pei, Hanmin Wang, Yue Ren, Haifeng Wang, Weimin Liu
doi:10.1016/j.compositesb.2024.111222
在原位高熵块状金属玻璃复合材料中同时实现强度-电导率组合和强大的抗磨损性能
High-entropy bulk metallic glasses (HE-BMGs) with desired thermal stability often exhibit limited plasticity due to the occurrence of shear localization avalanches. The present study reports the fabrication of a novel composite TiZrHfNb0.5Cu0.5Be0.5, consisting of a high entropy crystalline phase (TiZrHfNb) and an amorphous matrix (TiZrHfCuBe). The composite exhibits a distinctive combination of strength and ductility, surpassing that of traditional BMG composites, along with a notable capacity for work-hardening. Furthermore, it demonstrates exceptional wear resistance under varying normal loads or frequencies. The deformation and wear mechanisms are attributed to the solid-solution strengthening and stress-induced β→α" martensitic transformation in the high entropy crystalline phase, as well as the deformation-induced crystallization in HE-BMG matrix. These findings would provide a new strategy for preparing advanced HE-BMGs composite with unique properties.
In-situ constructing hybrid cross-linked networks in brominated butyl rubber via amphiphilic graphene oxide cross-linkers: Retaining excellent gas barrier and mechanical properties after fatigue
Rubber/graphene nanocomposites as gas barrier materials have attracted great interest in recent years. However, it is still a challenge to construct strong covalent interfaces between nonpolar rubber matrix and graphene for retaining excellent gas barrier and mechanical properties of aircraft tires after fatigue. In this work, hybrid cross-linked networks in brominated butyl rubber (BIIR) are first proposed and in-situ constructed successfully via introducing the amphiphilic graphene oxide cross-linkers (R-aGO). R-aGO can participate in the curing of BIIR to form hybrid cross-linked networks, which can force R-aGO to move with BIIR synchronously during fatigue deformation due to strong interfaces between BIIR and R-aGO via covalent bonds. When R-aGO content is 3 phr, the BIIR/R-aGO nanocomposites show a 27 % improvement in gas barrier property, a 230 % increase in strength at 40 % strain (suffered deformation of aircraft tires), and a 229 % enhancement in tensile strength relative to conventional BIIR/aGO nanocomposites with interfacial modifiers. More importantly, BIIR/R-aGO nanocomposites still retain excellent gas barrier and mechanical properties even after 500,000 load cycles (40 % strain). This work provides a novel route to fabricate rubber/graphene nanocomposites with superior gas barrier and mechanical properties, especially after fatigue.
Hot deformation plays a crucial role in the strengthening and toughening of aluminum matrix composites, but the high hot deformation resistance and the microstructure defects generated after deformation need to be solved urgently. In this paper, a new material, B4C@B2O3/Al composites, with the low melting point B2O3 phase at the interface, has been successfully prepared and the hot deformation behavior was studied in detail. By comparison, the hot deformation resistance and activation energy of the B4C@B2O3/Al composites is significantly lower than that of the B4C/Al composites. The softening mechanism of the B4C@B2O3/Al composites is mainly dynamic recrystallization (DRX) and the critical stress of DRX is much lower for the B4C@B2O3/Al composites than for the B4C/Al composites, while the volume fraction of DRX is higher than for the B4C/Al composites. Compared with the B4C/Al composites with similar particle content, the hot deformation temperature of the B4C@B2O3/Al composites decreases, but with high strength-plasticity compatibility (with tensile strength of 560 MPa and elongation of 4.2 %). This work provides an effective method to reduce the hot deformation resistance of the B4C/Al composites and explains the micro mechanism, guiding low-stress forming of the B4C/Al composites with high volume fraction and good mechanical properties.
Highly thermally conductive and soft thermal interface materials based on vertically oriented film
Hongyu Niu, Haichang Guo, Lei Kang, Liucheng Ren, Ruicong Lv, Lei Liu, Akbar Bashir, Shulin Bai
doi:10.1016/j.compositesb.2024.111219
基于垂直取向薄膜的高导热性软导热界面材料
Thermal interface materials (TIMs) with high through-plane thermal conductivity (TC), softness, and electrical insulation are highly desired for modern electronics. However, it is challenging to simultaneously achieve these properties. Boron nitride (BN)-based polymer composites are promising candidates for advanced TIMs owing to the high TC and great electrical insulation of BN. However, previous works perform either low TC (<8 W m−1 K−1) or high stiffness. The ultimate properties of BN-based TIMs remain largely unclear and unrealized. Here, we fabricate BN film-filled silicone rubber composites by a facile stacking-cutting method, which maintains the high degree of orientation the BN film, so that a record-high though-plane TC of 19.1 W m−1 K−1 and a low compressive modulus of 5.42 MPa are achieved. The low BN content (37 vol%) ensures the softness and resilience of the as-prepared TIMs. This work presents a highly efficient strategy to enhance the performance of BN based TIMs, promoting their large-scale manufacturing and practical applications.
热界面材料（TIMs）具有较高的通面热导率（TC）、柔软性和电绝缘性，是现代电子产品所亟需的。然而，要同时实现这些特性却极具挑战性。氮化硼（BN）基聚合物复合材料具有高热导率和良好的电绝缘性，因此有望成为先进 TIM 的候选材料。然而，以往的研究结果表明，这种复合材料要么具有低 TC 值（<8 W m-1 K-1），要么具有高刚度。BN 基 TIMs 的最终特性在很大程度上仍不清楚，也未实现。在这里，我们采用简便的堆叠切割法制造出了 BN 薄膜填充硅橡胶复合材料，该方法保持了 BN 薄膜的高取向度，从而实现了 19.1 W m-1 K-1 的创纪录高平面 TC 值和 5.42 MPa 的低压缩模量。较低的 BN 含量（37 Vol%）确保了制备的 TIM 的柔软性和韧性。这项研究提出了一种高效的策略来提高基于 BN 的 TIM 的性能，从而促进其大规模制造和实际应用。
Composites Science and Technology
Intermolecular interactions in graphene and oxidized graphene nanocomposites
Matthew Reil, Joseph Hoffman, Paul Predecki, Maciej Kumosa
doi:10.1016/j.compscitech.2024.110433
石墨烯和氧化石墨烯纳米复合材料中的分子间相互作用
The spatial arrangement of graphene (G) or graphene oxide (GO) nanoplate agglomerations will significantly impact the material properties of graphene-based polymer nanocomposites. Therefore, we investigated the stability of G and GO agglomerates without the presence of a polymer network using molecular dynamics (MD) simulations, which was not considered in our previous work (Reil, 2022) [15]; [16]. G and GO nanoplates, often procured in powder forms, display a significant volume difference by visual observation. To this end, MD simulations were performed to model G or GO agglomerations in the powder form, including the effects of varied plate dimensions and localized surface oxidation. G plates on average released 231 kcal/mol upon agglomerating into aligned stacks, closely matching results in the literature. Simulations of GO resulted in agglomerations of clusters of plates rather than aligned stacks, releasing on average 16 % less energy than G. The clustered arrangement of GO plate agglomerates in simulations occupied a volume approximately 7x that of the aligned stack G plates, closely replicating the experimentally determined volume ratio of 10x. This research could yield further insight into the behavior of G and GO when in the presence of various polymer networks, which could be different than in isolation.
石墨烯（G）或氧化石墨烯（GO）纳米团聚体的空间排列将对石墨烯基聚合物纳米复合材料的材料特性产生重大影响。因此，我们利用分子动力学（MD）模拟研究了在没有聚合物网络存在的情况下 G 和 GO 团聚体的稳定性，这在我们之前的工作（Reil，2022 年）[15]；[16]中没有考虑到。G 纳米板和 GO 纳米板通常以粉末形式获得，目测它们的体积差异很大。为此，我们进行了 MD 模拟，以模拟粉末形式的 G 或 GO 团聚，包括不同板材尺寸和局部表面氧化的影响。G 板在团聚成排列整齐的堆栈时平均释放了 231 kcal/mol，与文献中的结果非常接近。在模拟中，GO 板团聚成团的体积约为排列整齐的 G 板的 7 倍，与实验测定的 10 倍体积比基本一致。这项研究可以进一步了解 G 和 GO 在各种聚合物网络存在时的行为，这可能不同于孤立存在时的行为。
