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【新文速递】2024年1月12日复合材料SCI期刊最新文章

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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.

本文利用幅频响应曲线、分岔图、Lyapunov 指数和 Poincaré 图分析了石墨烯增强铝基航空发动机叶片在主共振下的非线性动力学行为。研究了石墨烯增强铝基航空发动机叶片的横向气动载荷、纵向气动载荷、离心力和温度。考虑了功能石墨烯增强梯度的三种配置。复合材料的有效杨氏模量由 Halpin-Tsai 模式给出。混合物的规则给出了其他材料特性。结果表明,在发动机转速的扰动下,叶片模态振幅与横向气动载荷、纵向气动载荷和温度的分岔图具有周期性混沌动态演化过程。当扰动振幅达到特定值时,新一轮的周期性混沌动态演化将继续进行。研究结果还清楚地表明,航空发动机叶片具有丰富而复杂的非线性动力学行为,包括超混沌、混沌、近周期、典型周期-加倍分叉和反周期-加倍分叉振动。这项研究更有助于工程师理解叶片的非线性动态行为。


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.

用于热塑性复合材料的激光辅助自动纤维铺放技术已显示出其在加工形状复杂的部件方面具有高生产率的潜力,但要实现适当的原位固结,仍需应对许多物理和技术方面的挑战。要确保高质量地粘合已铺设的带子,就必须在整个过程中对其热历史进行完美控制,而热传导早已被证明是实现这一目标的关键。许多热传导模型都考虑了激光与复合材料在宏观尺度上的光学相互作用。在此,我们设计了一个微观尺度的热光学模型,该模型将纤维与基体域区分开来,并考虑了它们各自的特性。在静态配置中对单条胶带进行建模。基于复合材料的现实微观结构,光线跟踪算法突出了激光吸热深度与激光入射角和纤维分布的关系。将数值表面温度与通过特定设置获得的实验数据进行了比较,从而得出了总体准确的近似值。最后,通过考虑理想表面加热或体积热源的一维均质模型评估了微观结构模型的相关性。表面加热模型导致表面温度近似不准确,而体积热源吸收则大大限制了温度误差。因此,该模型在模型复杂性、计算时间和温度预测之间实现了令人满意的折中。


Composites Part B: Engineering

Effects of hexagonal boron nitride content on forming quality and performance of laser powder bed fusion manufactured nickel-based hastelloy X composites

Jingjia Sun, Dongdong Gu, Guangjing Huang, KeYu Shi, Rui Wang, Ruiqi Wang, Yuxi Zhang, Liang Wang

doi:10.1016/j.compositesb.2024.111218

六方氮化硼含量对激光粉末床熔融制造的镍基哈氏合金 X 复合材料成型质量和性能的影响

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.

调节镍基复合材料的成分,尤其是含有对裂纹敏感的哈氏合金 X(HX)基体的复合材料的成分,会显著影响使用激光粉末床熔融(LPBF)制造的零件的成型质量和性能。为了分析激光加工六方氮化硼(h-BN)-HX 系统的非平衡凝固机制,我们进行了射线跟踪和温度场模拟,从而优化了 h-BN 的含量范围。HX 中含 0.2 wt.% h-BN 的优化组合显示出最佳的成型质量和性能。它的裂纹或未熔化颗粒几乎可以忽略不计,表面粗糙度最小为 9.29 μm,拉伸性能优越,拉伸强度为 1246.49 MPa,伸长率为 18.67%。此外,样品的硬度(371.21 HV5)和摩擦系数(0.54)都有所提高。有趣的是,随着 h-BN 含量的进一步增加,强度和硬度逐渐提高,同时摩擦系数降低。然而,样品的延展性明显下降。1 wt.% h-BN/HX 样品的拉伸强度为 1503.14 MPa,硬度为 502.13 HV5,摩擦系数为 0.48,而伸长率仅为 3.76 %。这些发现强调了优化镍基复合材料成分以提高通过 LPBF 制造的零件的成型质量和性能的重要性,尤其是在航空航天和工程应用领域。


Co-delivery of Zn ions and resveratrol via bioactive glass-integrated injectable microspheres for postoperative regeneration of bone tumor defects

Qiyuan Dai, Maocai Li, Xiyuan Han, Zetao Wang, Yilin Ding, Qi Feng, XiaoYing Wang, Qingtao Li, Xiaodong Cao

doi:10.1016/j.compositesb.2024.111220

通过生物活性玻璃集成注射微球共同释放锌离子和白藜芦醇,促进骨肿瘤缺损的术后再生

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.

具有理想热稳定性的高熵块状金属玻璃(HE-BMGs)通常会因发生剪切定位雪崩而表现出有限的可塑性。本研究报告了一种新型复合材料 TiZrHfNb0.5Cu0.5Be0.5的制造过程,它由高熵结晶相(TiZrHfNb)和无定形基体(TiZrHfCuBe)组成。这种复合材料在强度和延展性方面表现出独特的组合,超过了传统的 BMG 复合材料,同时还具有显著的加工硬化能力。此外,在不同的正常载荷或频率下,它还表现出卓越的耐磨性。其变形和磨损机理可归因于固溶强化和应力诱导的高熵结晶相中的 β→α" 马氏体转变,以及 HE-BMG 基体中的变形诱导结晶。这些发现将为制备具有独特性能的先进 HE-BMG 复合材料提供一种新策略。


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

Siqiang Yang, Hong Wu, Ying Xiong, Shaoyun Guo

doi:10.1016/j.compositesb.2024.111224

 

通过两亲性氧化石墨烯交联剂在溴化丁基橡胶中原位构建混合交联网络:疲劳后仍能保持优异的气体阻隔性和机械性能

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.

近年来,橡胶/石墨烯纳米复合材料作为气体阻隔材料引起了人们的极大兴趣。然而,如何在非极性橡胶基体和石墨烯之间构建强共价界面,使飞机轮胎在疲劳后仍能保持良好的气体阻隔性和机械性能,仍是一项挑战。本研究首次提出了溴化丁基橡胶(BIIR)中的混合交联网络,并通过引入两亲性氧化石墨烯交联剂(R-aGO)成功地在原位构建了该网络。R-aGO 可参与 BIIR 的固化形成混合交联网络,由于 BIIR 与 R-aGO 之间通过共价键形成的强界面,可迫使 R-aGO 在疲劳变形过程中与 BIIR 同步移动。当 R-aGO 含量为 3 phr 时,BIIR/R-aGO 纳米复合材料的气体阻隔性能提高了 27%,在 40% 应变(飞机轮胎的受力变形)时的强度提高了 230%,拉伸强度比传统的含界面改性剂的 BIIR/aGO 纳米复合材料提高了 229%。更重要的是,BIIR/R-aGO 纳米复合材料在经过 500,000 次负载循环(40% 应变)后仍能保持优异的气体阻隔性和机械性能。这项研究为制造具有优异气体阻隔性和机械性能(尤其是疲劳后)的橡胶/石墨烯纳米复合材料提供了一条新途径。


Research on low flow stress and quantitative DRX analysis in B4C/Al composites with interfacial amorphous B2O3 layer

Wei Xue, Zhenlong Chao, Huimin Han, Qiqi Zhao, Bingzhuo Han, Shanqi Du, Pengchao Kang, Yong Mei, Longtao Jiang

doi:10.1016/j.compositesb.2024.111226

带界面无定形 B2O3 层的 B4C/Al 复合材料中的低流动应力和 DRX 定量分析研究

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.

热变形在铝基复合材料的强化和增韧中起着至关重要的作用,但高热变形阻力和变形后产生的微观结构缺陷亟待解决。本文成功制备了界面具有低熔点 B2O3 相的新型材料 B4C@B2O3/Al复合材料,并对其热变形行为进行了详细研究。通过比较,B4C@B2O3/Al 复合材料的热变形阻力和活化能明显低于 B4C/Al 复合材料。B4C@B2O3/Al 复合材料的软化机制主要是动态再结晶(DRX),B4C@B2O3/Al 复合材料的 DRX 临界应力比 B4C/Al 复合材料低得多,而 DRX 的体积分数比 B4C/Al 复合材料高。与颗粒含量相近的 B4C/Al 复合材料相比,B4C@B2O3/Al 复合材料的热变形温度降低,但强度-塑性兼容性高(抗拉强度为 560 兆帕,伸长率为 4.2%)。这项研究提供了一种降低 B4C/Al 复合材料热变形阻力的有效方法,并解释了其微观机理,指导了具有高体积分数和良好力学性能的 B4C/Al 复合材料的低应力成型。


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。



来源:复合材料力学仿真Composites FEM
ACTMechanicalOpticalSystemDeform振动疲劳复合材料非线性光学航空航天电子裂纹理论化机材料分子动力学
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【新文速递】2023年12月30日固体力学SCI期刊最新文章

今日更新:International Journal of Solids and Structures 2 篇,Journal of the Mechanics and Physics of Solids 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 2 篇International Journal of Solids and StructuresPhase-field modeling of anisotropic crack propagation based on higher-order nonlocal operator theoryNhon Nguyen-Thanh, Timon Rabczukdoi:10.1016/j.ijsolstr.2023.112632基于高阶非局部算子理论的各向异性裂纹扩展相场建模This paper presents a novel higher-order nonlocal operator theory for the phase-field modeling of brittle fracture in anisotropic materials. Incorporating higher order nonlocal operators can enhance the accuracy of the phase-field model by effectively capturing long-range interactions that hold significance in numerous materials. The reproducing kernel particle method is employed to derive a nonlocal differential operator to enhance computational stability and accuracy. Moreover, the proposed method eliminates the need for direct computation of derivatives of the modified kernel function, which avoids the calculation of moment matrix derivatives and improves computational efficiency. The phase-field modeling of polycrystalline materials, considering the anisotropic fracture resistance of each grain, is implemented using this numerical framework. The present method is able to capture different scenarios intergranular and transgranular crack propagation patterns in polycrystalline materials. The proposed method involves a detailed representation of the complex process of crack initiation and propagation in 2D and 3D models of polycrystalline materials.提出了一种新的高阶非局部算子理论,用于各向异性材料脆性断裂相场建模。结合高阶非局部算符可以通过有效地捕获在许多材料中具有重要意义的远程相互作用来提高相场模型的准确性。采用再现核粒子法推导非局部微分算子,提高了计算的稳定性和精度。此外,该方法不需要直接计算修正核函数的导数,避免了矩矩阵导数的计算,提高了计算效率。采用该数值框架对多晶材料进行了相场建模,考虑了各晶粒的抗断裂性能各向异性。该方法能够捕获多晶材料中不同情况下的晶间和穿晶裂纹扩展模式。该方法在二维和三维多晶材料模型中详细描述了裂纹萌生和扩展的复杂过程。Fracture resistance enhanced by both nonlocal interaction and damping of locally resonant structureXuan Zhang, Yi-Ze Wangdoi:10.1016/j.ijsolstr.2023.112635非局部相互作用和局部共振结构的阻尼增强了抗断裂能力In this study, the arrest behavior of locally resonant structure with nonlocal interaction and damping are analyzed. Based on the Wiener-Hopf method, the energy release ratio G0/G which denotes the arrest property is derived. The effects of nonlocal interaction and damping parameters on the oscillation and stability regions during the crack growth are discussed. The arrest characteristics of three locally resonant structures are compared. In order to support the theoretical calculation, both the finite element simulation and fracture experiment are performed. Results show that the locally resonant structure with nonlocal interaction and damping has smaller energy release ratio G0/G. It indicates that the coupling of both nonlocal interaction and damping can significantly enhance the propagation resistance of crack propagation.本研究分析了具有非局部相互作用和阻尼的局部谐振结构的阻滞行为。基于 Wiener-Hopf 方法,推导出了表示停滞特性的能量释放比 G0/G。讨论了非局部相互作用和阻尼参数对裂纹生长过程中振荡区和稳定区的影响。比较了三种局部共振结构的抑制特性。为了支持理论计算,进行了有限元模拟和断裂实验。结果表明,具有非局部相互作用和阻尼的局部共振结构的能量释放比 G0/G 较小。这表明,非局部相互作用和阻尼的耦合可以显著增强裂纹的抗扩展能力。Journal of the Mechanics and Physics of SolidsRate Induced Thermomechanical Interactions in NiTi Tensile Tests on StripsSolon Tsimpoukis, Stelios Kyriakidesdoi:10.1016/j.jmps.2023.105530带材镍钛拉伸试验中速率诱导的热-机械相互作用The paper uses tensile experiments on NiTi strips at different displacement rates to establish and simulate the thermomechanical interactions caused by the latent heat of the reversible transformation between the austenitic and martensitic phases. The evolution of deformation in the specimen is synchronously monitored with digital image correlation, and the temperature field through infrared imaging, essential for structural modelling. Transformation leads to localized deformation that propagates through the specimen, while the latent heat released/absorbed at the propagating fronts locally heats/cools the specimen. The sensitivity of the transformation stress to temperature results in a complex interaction between the heat transfer conditions and the nucleation and evolution of transformation in the specimen. At low rates of loading, the alternate phase propagates nearly isothermally with a small number of fronts producing relatively flat stress plateaus. Higher rates lead to significant heating/cooling that results in progressive nucleation of multiple fronts and apparent &quot;hardening&quot; responses. The experiments are simulated in a three-dimensional static displacement transient temperature finite element analysis, using a new fully coupled thermomechanical constitutive model. Transformation strain and entropy are its internal variables whose evolution is governed by the motion in the stress-temperature space of a single transformation surface governing both transformations. The prevailing localization is captured by the introduction of softening over the unstable branches of the recorded isothermal material response. The results demonstrate how the important role of the thermal interaction between the specimen and the environment can be addressed. This, together with appropriate calibration of the constitutive and structural model, enable the analysis to reproduce the effect of rate on the recorded response, the evolution of localization patterns, and the associated thermal fields. The results can guide the development of constitutive and structural models of phase transforming materials with strong thermomechanical interactions.本文采用不同位移速率下NiTi带材的拉伸实验,建立并模拟了奥氏体与马氏体可逆相变潜热引起的热力相互作用。通过数字图像相关同步监测试样的变形演变,并通过红外成像同步监测温度场,这对结构建模至关重要。相变导致局部变形在试样中传播,而在传播前沿释放/吸收的潜热局部加热/冷却试样。相变应力对温度的敏感性导致传热条件与试样的形核和相变演化之间存在复杂的相互作用。在低加载速率下,交替相几乎等温传播,少数锋面产生相对平坦的应力高原。较高的速率导致显著的加热/冷却,导致多个锋面逐渐成核和明显的“硬化”反应。采用一种新的全耦合热-力本构模型,对实验进行了三维静位移瞬态温度有限元模拟。相变应变和熵是其内部变量,其演化由控制两种相变的单一相变表面在应力-温度空间中的运动决定。通过在记录的等温材料响应的不稳定分支上引入软化,捕获了普遍的局部化。结果表明,如何在试样和环境之间的热相互作用的重要作用可以解决。这与本构和结构模型的适当校准一起,使分析能够重现速率对记录响应的影响,定位模式的演变以及相关的热场。研究结果对具有强热力相互作用的相变材料的本构模型和结构模型的建立具有指导意义。International Journal of PlasticityRevealing the effects of martensitic transformation and dislocation slip in austenite on the micromechanical behaviors of a 9Ni steel using crystal plasticity finite element methodW.X. Zhang, Y.B. Cong, J. Wang, C. Li, J. Wan, Y.Z. Chendoi:10.1016/j.ijplas.2023.103869 利用晶体塑性有限元法揭示了马氏体相变和奥氏体 位错滑移对9Ni钢微观力学行为的影响Austenite is an extremely important phase that significantly influence the mechanical properties of (austenite + martensite) duplex steels. Two different deformation mechanisms, i.e., dislocation slip and martensitic transformation, can be activated in the austenite upon plastic deformation. However, these two deformation mechanisms make different contributions to the work hardening and flow stress of the austenite which are hardly separated by experimental methods, making it difficult to clarify the effect of austenite on the micromechanical behavior of (austenite + martensite) duplex steels. In this work, the influence of martensitic transformation and dislocation slip in austenite on the micromechanical behaviors is investigated in a model 9Ni steel consisting of austenite and tempered martensite (TM) using the crystal plasticity finite element method (CPFEM). The austenite and fresh martensite (FM) formed within the austenite grain upon deformation process are regarded as a whole named as FM/A island in the CPFEM. To accurately model the rate of martensitic transformation, the martensitic transformation kinetics law used in the CPFEM is developed by relating the number of possible nucleation sites for fresh martensite to the mechanical driving force originating from the resolved shear stress on each transformation system. The material parameters for the TM were determined by micropillar compression tests. Besides, the method for separating and determining the material parameters accounting for dislocation slip in austenite and martensitic transformation by a combination of neutron diffraction and measurements of stress-strain curves and austenite volume fractions is developed and exemplified. The CPFEM simulation results show that the local concentration of equivalent plastic strain and stress triaxiality in the FM/A island can be enhanced by the dislocation slip in austenite but suppressed by the martensitic transformation. In addition, the martensitic transformation has a remarkable effect on strengthening the local concentration of maximum principal stress in the FM/A island.奥氏体是影响(奥氏体 + 马氏体)双相钢力学性能的重要相。塑性变形时,奥氏体可激活两种不同的变形机制,即位错滑移和马氏体相变。然而,这两种变形机制对奥氏体的加工硬化和流动应力的贡献各不相同,且难以通过实验方法加以区分,因此很难阐明奥氏体对(奥氏体 + 马氏体)双相钢微观力学行为的影响。本文采用晶体塑性有限元法(CPFEM)研究了奥氏体和回火马氏体(TM)组成的9Ni钢中马氏体相变和位错滑移对微观力学行为的影响。在CPFEM中,将形变过程中在奥氏体晶粒内形成的奥氏体和新马氏体(FM)视为一个整体,称为FM/ a岛。为了准确地模拟马氏体转变的速率,CPFEM中使用的马氏体转变动力学定律是通过将新马氏体可能成核的位置的数量与每个转变系统上由分解的剪切应力产生的机械驱动力相关联而建立的。通过微柱压缩试验确定了TM的材料参数。此外,还提出了利用中子衍射、应力-应变曲线和奥氏体体积分数测量相结合的方法来分离和确定奥氏体和马氏体相变中位错滑移的材料参数。CPFEM模拟结果表明,奥氏体 位错滑移增强了FM/A岛的局部等效塑性应变集中和应力三轴性,但马氏体相变抑制了等效塑性应变的集中。此外,马氏体相变对强化FM/ a岛局部最大主应力集中有显著作用。Thin-Walled StructuresExperimental and numerical study on the lightweight design of load-bearing energy absorption structure for subway trainJialin Li, Guangjun Gao, Yao Yu, Tianyu Zhuo, Jian Lidoi:10.1016/j.tws.2023.111542地铁列车承载吸能结构轻量化设计的试验与数值研究The load-bearing underframe is widely utilized on the crashworthiness design of subway trains. However, studies on load-bearing underframes mainly focused on conceptual design and structural optimization, and didn&#39;t consider the combination of bearing loads during the normal operation and absorbing impact kinetic energy under collisions. In addition, the traditional load-bearing underframe for subway trains is mainly made of stainless steel, which has a relatively large weight and cannot meet the requirement of lightweight design. To address these limitations, this paper presents a novel lightweight aluminum alloy load-bearing underframe with the alternative thin-walled energy absorption component, which can both satisfy the function of bearing loads and energy absorption. Firstly, the impact tests and numerical simulations are conducted to compare the crashworthiness of the energy absorption component, i.e., the thin-walled square tube made of S304 (abbreviated as S3N4) and aluminum alloy 5083P-O (abbreviated as A3N4). The result shows that S3N4 has higher energy absorption and mean crushing force, and A3N4 is 56.94 % lower than S3N4 in initial peak crushing force and 53.79 % higher in special energy absorption. Then, the aluminum alloy thin-walled tube is adopted on the novel load-bearing underframe and the parameter study on the wall thickness and number of diaphragms for the energy absorption component is conducted. The result reveals that the 5083P-O thin-walled tube with 5 mm wall thickness and 4 diaphragms can provide the stable and ordered deformation mode and high energy absorption. Finally, a real vehicle impact test is conducted to verify the crashworthiness of the optimized load-bearing underframe, which shows that the deformation modes and mechanical responses are consistent with the numerical simulation. The proposed aluminum alloy load-bearing underframe energy absorption structure can be adopted on subway trains.在地铁列车的耐撞性设计中,承重型车架得到了广泛的应用。然而,对承重型车架的研究主要集中在概念设计和结构优化上,没有考虑车架正常运行时承受载荷与碰撞时吸收冲击动能的结合。此外,传统的地铁列车承重底架以不锈钢为主,自重较大,不能满足轻量化设计的要求。针对这些局限性,本文提出了一种新型的轻质铝合金承载底架,并采用替代薄壁吸能组件,既能满足承载载荷又能满足吸能功能。首先,对S304薄壁方管(简称S3N4)和5083P-O铝合金(简称A3N4)两种吸能构件的耐撞性进行了冲击试验和数值模拟比较。结果表明,S3N4具有更高的能量吸收和平均破碎力,A3N4初始峰值破碎力比S3N4低56.94%,特殊能量吸收比S3N4高53.79%。然后,在新型承力底架上采用铝合金薄壁管,对吸能构件的壁厚和隔板数进行了参数研究。结果表明:5083P-O薄壁管的壁厚为5mm,隔板为4个,可以提供稳定有序的变形模式和较高的能量吸收。最后,进行了实车碰撞试验,验证了优化后的承载底架的耐撞性,结果表明,其变形模式和力学响应与数值模拟结果一致。本文提出的铝合金承力底架吸能结构可用于地铁列车。An all-composite sandwich structure with PMI foam-filled for adjustable vibration suppression and improved mechanical propertiesJiaming Sun, Leilei Yan, Keyu Zhu, Pengfei Jiang, Yanlong Xu, Xitao Zhengdoi:10.1016/j.tws.2023.111544采用PMI泡沫填充的全复合夹层结构,可调抑制振动,提高力学性能A novel all-composite double-layer sandwich structure with tubular cores (DSST) is designed and fabricated to achieve the both of vibration suppression and enhancement of mechanical properties. The suppression effect of the proposed sandwich structure on the structural vibration is verified numerically and experimentally, and the mechanism of bandgap generation as well the structural wave propagation modes are revealed and analyzed. The anisotropy of the carbon fiber reinforced polymer (CFRP) is utilized to enables the intermediate resonant layer to exist a wide frequency adjustment range of vibration suppression without altering its geometrical parameters. Then, the improvement of structural vibration characteristics (i.e., natural frequencies and mode shapes) by filling the polymethacrylimide (PMI) foam in the DSST is discussed. And PMI foam-filling also leads to improved mechanical properties, out-of-plane compression tests are conducted to reveal the mechanism of mechanical enhancement, and it is found that the interaction effect of the foam filled in DSST in the axial direction enhances the compressive strength and the specific energy absorption (SEA) compared to the one without foam by 35.7% and 26.2%, respectively. In addition, the core configuration and the composite material preparation enable the proposed structure to outperform competing ones in terms of load-bearing capacity and bandgap characteristics.设计并制造了一种新型的双层管状芯夹芯全复合材料结构(DSST),以达到抑制振动和提高力学性能的目的。通过数值和实验验证了夹层结构对结构振动的抑制作用,揭示和分析了带隙产生的机理以及结构波的传播模式。利用碳纤维增强聚合物(CFRP)的各向异性,使中间谐振层在不改变其几何参数的情况下存在较宽的频率调节范围来抑制振动。然后讨论了在DSST中填充聚甲基丙烯酰亚胺(PMI)泡沫对结构振动特性(即固有频率和振型)的改善。PMI泡沫填充也能改善材料的力学性能,通过面外压缩试验揭示了力学增强的机理,结果发现,在轴向填充泡沫后,材料的抗压强度和比能吸收(SEA)比未填充泡沫时分别提高了35.7%和26.2%。此外,核心配置和复合材料制备使所提出的结构在承载能力和带隙特性方面优于竞争结构。来源:复合材料力学仿真Composites FEM

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