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【新文速递】2024年11月4日固体力学SCI期刊最新文章

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今日更新:Journal of the Mechanics and Physics of Solids 1 篇,International Journal of Plasticity 1 篇,Thin-Walled Structures 2 篇

Journal of the Mechanics and Physics of Solids

On the effect of nuclear fission cladding stresses on Zirconium hydride orientation and dislocation strain energy fields via Discrete Dislocation Plasticity and Crystal Plasticity Finite Element modelling

Christos Skamniotis, Daniel Long, Mark Wenman, Daniel S. Balint

doi:10.1016/j.jmps.2024.105924

基于离散位错塑性和晶体塑性有限元模型的核裂变包层应力对氢化锆取向和位错应变能场的影响

The diffusion of hydrogen in Zircalloy fuel cladding components and its associated delayed hydride cracking (DHC) mechanism remain a bottleneck in nuclear fission. Through Crystal Plasticity Finite Element (CPFE) analysis at the grain scale (μm) and Discrete Dislocation Plasticity (DDP) at the hydride scale (nm), we explore how cladding stress history influences the dislocation network in a system of hydrides, and in turn, how this can impact hydrogen accumulation and embrittlement. CPFE indicates that high tensile stresses at service temperature can cause severe plasticity at a notch of a cladding component, leading to significant residual compressive stresses on service shutdown. As a result, hydrides evolve in this service scenario under a cyclic tensile-compressive background stress, which is found to enhance the ratchetting of dislocations compared to a typical constant background stress history and to eliminate the concentration of tensile residual hydrostatic stresses at the locations of dissolved hydrides. Since these tensile residual stresses drive the local accumulation of hydrogen during progressive precipitation-dissolution cycles, a key question is posed as to whether and how the sequencing of cladding stress-temperature reversals influences the growth rate of macro-hydride colonies. Simultaneously, we find that a large fraction of the total strain energy of hydrides is associated with the strain energy of dislocations and their interactions, posing the question of whether dislocation networks influence the energetically favourable hydride orientation. Our study provides a foundation for future studies of the DHC mechanism and drives the development of thermodynamically consistent dislocation-based models coupled with irradiation effects.

氢在锆合金燃料包壳组件中的扩散及其相关的延迟氢化物裂解(DHC)机制一直是核裂变研究的瓶颈。通过晶粒尺度(μm)的晶体塑性有限元(CPFE)和氢化物尺度(nm)的离散位错塑性(DDP)分析,我们探讨了包层应力历史如何影响氢化物体系中的位错网络,以及这如何影响氢的积累和脆化。CPFE表明,在工作温度下的高拉应力会导致包层部件缺口处的严重塑性,导致在工作关闭时产生显著的残余压应力。结果,氢化物在循环拉压背景应力下演化,与典型的恒定背景应力相比,这增强了位错的棘轮作用,并消除了溶解氢化物位置的拉伸残余静水应力集中。由于这些拉伸残余应力在渐进式沉淀-溶解循环中驱动氢的局部积累,因此提出了一个关键问题,即包层应力-温度逆转的顺序是否以及如何影响宏观氢化物菌落的生长速度。同时,我们发现氢化物总应变能的很大一部分与位错及其相互作用的应变能有关,这就提出了位错网络是否影响能量上有利的氢化物取向的问题。我们的研究为未来DHC机制的研究提供了基础,并推动了基于热动力学一致的位错耦合辐照效应模型的发展。


International Journal of Plasticity

Dynamic deformation and fracture of brass: Experiments and dislocation-based model

E.S. Rodionov, V.V. Pogorelko, V.G. Lupanov, A.G. Fazlitdinova, P.N. Mayer, A.E. Mayer

doi:10.1016/j.ijplas.2024.104165

黄铜的动态变形和断裂:实验和基于位错的模型

In this work, we perform a comprehensive study of the dynamic deformation and fracture of brass, including Taylor tests with classical and profiled cylinders and ball throwing experiments reaching the strain rates of about (0.1−1)/μs, as well as atomistic and continuum-level numerical modeling. Molecular dynamics (MD) simulations are used to construct the equation of state (EOS) of brass and to study its fracture characteristics at shear deformation under negative pressure. An original model of fracture under combined tensile-shear loading is formulated, which takes into account both the accumulation of empty volume in the process of lattice loosening due to the lattice defect production in the course of plastic deformation and further mechanical growth of voids controlled by the dislocation plasticity. This atomic-scale model is transmitted to the macroscopic experiment-scale level and embedded into 3D dislocation plasticity model to describe the dynamic deformation and fracture of brass using the numerical scheme of smoothed particle hydrodynamics (SPH). A part of experimental data is used to find the optimal parameters of the dislocation plasticity model by means of the Bayesian global optimization method accelerated with the help of artificial-neural-network (ANN)-based emulator of the 3D model. Another part of experimental data is used to fit the fracture model parameter. The remaining experimental data, which are not used in the parameterization, are applied to verify the parameterized model. The developed physical-based model provides correct and meaningful description of the dynamic deformation and fracture of brass, while the developed formalized approach to its parameterization opens a way to wider use of this type of models in the engineering applications, including studies on dynamic performance and high-speed processing technologies.

在这项工作中,我们对黄铜的动态变形和断裂进行了全面的研究,包括经典圆柱体和轮廓圆柱体的Taylor试验和应变速率约为(0.1−1)/μs的抛球实验,以及原子和连续水平的数值模拟。采用分子动力学(MD)模拟方法建立了黄铜的状态方程(EOS),研究了黄铜在负压剪切变形下的断裂特征。提出了一种原始的拉伸-剪切复合加载断裂模型,该模型既考虑了塑性变形过程中由于晶格缺陷产生的晶格松动过程中空洞体积的积累,又考虑了位错塑性控制下空洞的进一步力学增长。将该原子尺度模型传递到宏观实验尺度,并嵌入到三维位错塑性模型中,采用光滑颗粒流体力学(SPH)数值格式描述黄铜的动态变形和断裂。利用部分实验数据,利用基于人工神经网络(ANN)的三维模型仿真器加速贝叶斯全局优化方法,找到位错塑性模型的最优参数。另一部分实验数据用于拟合断裂模型参数。其余未用于参数化的实验数据用于验证参数化模型。所建立的基于物理的模型为黄铜的动态变形和断裂提供了正确而有意义的描述,而所建立的形式化参数化方法为这类模型在工程应用中的广泛应用开辟了道路,包括动态性能和高速加工技术的研究。


Thin-Walled Structures

An origami-wheeled robot with variable width and enhanced sand walking versatility

Jie Liu, Zufeng Pang, Zhiyong Li, Guilin Wen, Zhoucheng Su, Junfeng He, Kaiyue Liu, Dezheng Jiang, Zenan Li, Shouyan Chen, Yang Tian, Yi Min Xie, Zhenpei Wang, Zhuangjian Liu

doi:10.1016/j.tws.2024.112645

具有可变宽度的折纸轮式机器人,增强了沙地行走的多功能性

Robots inspired by origami that offer several benefits, including being lightweight, requiring less assembly, and possessing remarkable deformability, have drawn a lot of interest. However, the existing origami-inspired robots are usually of limited functionalities and developing feature-rich robots is very challenging. Here, we report an origami-wheeled robot (OriWheelBot) with exceptional mobility for sand walking and a changing width. Origami wheels created using Miura origami permit the OriWheelBot to alter wheel width over obstacles. We derive the variable-width and diameter analytical models of the origami wheel, assuming rigid-folding, which has been confirmed by testing. An enhanced variant, dubbed iOriWheelBot, is additionally being developed to autonomously determine the obstacle's breadth. Based on the width of the channel between the barriers, three actions will be executed: direct pass, variable width pass, and direct return. Sand-pushing is more suitable for walking on the sand than sand-digging, which is the other of the two motion mechanisms that we have identified. Many aspects of sand walking, including carrying loads, walking on a slope, climbing a slope, and negotiating sand pits, small rocks, and sand traps, have been methodically investigated. The OriWheelBot can climb a 17-degree sand incline, vary its width by 40%, and have a loading-carrying ratio of 66.7% on flat sand. Rescue operations in disaster areas and planetary subsurface exploration can benefit from the OriWheelBot.

受折纸启发的机器人有很多优点,包括重量轻、装配少、具有显著的可变形性,这些都引起了人们的兴趣。然而,现有的折纸机器人通常功能有限,开发功能丰富的机器人是非常具有挑战性的。在这里,我们报告了一种折纸轮式机器人(OriWheelBot),它具有特殊的沙子行走机动性和变化的宽度。使用三浦折纸技术创建的折纸轮子允许OriWheelBot在障碍物上改变轮子的宽度。在刚性折叠条件下,建立了折纸轮变宽度和变直径的解析模型,并通过试验得到了验证。另外,一款名为iOriWheelBot的增强版本正在开发中,可以自动确定障碍物的宽度。根据障碍物之间通道的宽度,将执行三种动作:直接通过、变宽通过和直接返回。推沙 比挖沙更适合在沙子上行走,这是我们已经确定的两种运动机制中的另一种。沙地行走的许多方面,包括负重、在斜坡上行走、爬坡、通过沙坑、小岩石和沙坑,都被系统地研究过。OriWheelBot可以爬上17度的沙坡,宽度可变化40%,在平坦的沙地上承载率为66.7%。在灾区的救援行动和行星地下勘探可以受益于OriWheelBot。


Oscillating laser-arc hybrid additive manufacturing of aluminum alloy thin-wall based on synchronous wire-powder feeding

Yunfei Meng, Qianxi Yu, Xu Wu, Xiaohan Guo, Ziheng Yang, Lidong Xu, Hui Chen

doi:10.1016/j.tws.2024.112665

基于同步送粉的铝合金薄壁振荡激光-电弧复合增材制造

Synchronous wire-powder feeding was adopted to overcome the poor mechanical properties of aluminum alloy thin-wall caused by limited filling composition in wire-based laser-arc hybrid additive manufacturing. The results showed that the optimized Mg powder feeding improved the droplet transfer into a fine spray mode with reduced transition time by 18%. Moreover, not only the effective width coefficient of thin-wall increased from 89% to 95%, but also the subsequent machining allowance reduced from 1.25 to 0.48 mm. The synchronous wire-powder feeding improved the formation accuracy by 61.6%. Although the deposition microstructure was mainly composed of dendrites with obvious direction and increased average grain size by 54%, a new Mg2Si strengthened phase was also found. The ultimate tensile strength of thin-wall was increased by 12% from 227.3 to 255.5 MPa. The related evolution mechanisms of deposition stability and mechanical properties by optimized powder feeding on the hybrid additive manufacturing were mainly discussed.

采用同步线粉进料的方法,克服了线基激光-电弧复合增材制造中填充成分有限导致铝合金薄壁力学性能差的问题。结果表明,优化后的Mg粉进料使液滴转变为细喷雾,转变时间缩短了18%。薄壁有效宽度系数由89%提高到95%,后续加工余量由1.25 mm减小到0.48 mm。同步送粉使成形精度提高了61.6%。虽然沉积组织主要由方向性明显的枝晶组成,平均晶粒尺寸增加了54%,但也发现了新的Mg2Si强化相。薄壁的极限抗拉强度由227.3 MPa提高到255.5 MPa,提高了12%。重点讨论了混合增材制造中优化进料对沉积稳定性和力学性能的影响机理。




来源:复合材料力学仿真Composites FEM
ACTMechanicalAdditiveSystemInspire断裂增材机器人分子动力学控制试验装配
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首次发布时间:2024-11-16
最近编辑:11天前
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【新文速递】2024年11月5日复合材料SCI期刊最新文章

今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 1 篇Composites Part A: Applied Science and ManufacturingMaking aerogel films like playing LEGO: A universal fabrication strategy for Kevlar based aerogel films with arbitrarily designed functionsJiaxin Liu, Ziyang Ke, Zhe Wang, Yang Zhou, Guan Yeoh, Carlo Carraro, Guanglan Liao, Roya Maboudian, Tielin Shi, Hu Longdoi:10.1016/j.compositesa.2024.108566像玩乐高一样制作气凝胶薄膜:具有任意设计功能的凯夫拉尔基气凝胶薄膜的通用制造策略Highly flexible, ultrathin and mechanically robust aerogel films activated by functional nanofillers exhibit tremendous potentials for wide applications. However, it is difficult to design different functionalities in a single aerogel film, as different nanofillers often possess opposing properties. Herein, a LEGO®-inspired fabrication strategy to construct Kevlar-based aerogel film with arbitrarily designed functions is introduced by stacking functionalized aerogel film units as stacking LEGO® bricks. The aerogel film units are reliably connected by precursor dispersion-derived LEGO® embossed nodes, leading to superior mechanical strength. Moreover, owing to the flexibility of the LEGO®-inspired assembly method, targeted functions of the aerogel films can be achieved by designing and purposefully combining various stacks. As demonstrations, optimized joule heating, greatly enhanced electromagnetic wave shielding and excellent flame-retardant properties are realized with stacking of different aerogel film units. The unique fabrication strategy opens up opportunities for the design and fabrication of aerogel film with tunable and tailored properties for wide applications.功能化纳米填料活化的高柔韧性、超薄、机械强度高的气凝胶膜具有广阔的应用前景。然而,很难在单个气凝胶膜中设计不同的功能,因为不同的纳米填料通常具有相反的性质。本文介绍了一种受LEGO®启发的制造策略,通过将功能化气凝胶膜单元堆叠为堆叠LEGO®砖块,构建具有任意设计功能的凯夫拉气凝胶膜。气凝胶膜单元通过前驱体分散衍生的LEGO®压花节点可靠地连接在一起,从而具有优越的机械强度。此外,由于乐高®启发组装方法的灵活性,气凝胶膜的目标功能可以通过设计和有目的地组合各种堆栈来实现。结果表明,通过不同气凝胶单元的叠加,可实现焦耳加热优化、电磁波屏蔽能力大大增强和阻燃性能优异。独特的制造策略为设计和制造具有可调和定制性能的气凝胶膜提供了机会,可广泛应用。Composites Part B: EngineeringEnhancing Microwave Absorption of Bio-inspired Structure through 3D Printed Concentric Infill PatternHuaiyu Dong, Shuailong Gao, Chen Yu, Zhichen Wang, Yixing Huang, Tian Zhao, Ying Lidoi:10.1016/j.compositesb.2024.111924通过3D打印同心填充图案增强仿生结构的微波吸收Despite numerous reports on microwave absorbing materials and structures with excellent performance, research on the impact of the carrier of microwave absorbers and their preparation processes on microwave absorption performance still faces challenges. To address this issue, this study combines theoretical analysis, simulation, and experimental validation to compare the differences in microwave absorption performance between 3D printed ABS/CF/MWCNTs materials and traditionally cast paraffin/CF/MWCNTs materials. Furthermore, the study explores the impact of linear and concentric filling patterns in 3D printing processes on the performance of tree-shaped microwave absorbing meta-structures. From a material level perspective, the 3D printed ABS/CF/MWCNTs composite plate with a thickness of 3mm has an effective absorption bandwidth of 5.16 GHz. Additionally, the bio-inspired tree-shaped structure optimized by the ant colony algorithm achieves an effective absorption bandwidth of up to 11.5 GHz at a thickness of 10.8 mm, with a minimum reflection loss of less than -9 dB across the entire frequency range (2 to 18 GHz). Moreover, the microwave absorbing meta-structure reinforced with carbon fiber-reinforced plastic laminates exhibits outstanding tensile and bending strength, with an average tensile strength and bending strength reaching 197.7 MPa and 188.6 MPa, respectively. In summary, this study provides valuable insights into the optimization of preparation processes for microwave absorbing materials or structures and offers a scientific basis for the design and application of high-performance microwave absorbing materials.尽管已有大量研究报道了性能优异的吸波材料和结构,但研究微波吸收剂的载体及其制备工艺对微波吸收性能的影响仍然面临挑战。为了解决这一问题,本研究将理论分析、仿真和实验验证相结合,比较3D打印ABS/CF/MWCNTs材料与传统铸造石蜡/CF/MWCNTs材料在微波吸收性能上的差异。此外,该研究还探讨了3D打印过程中线性和同心填充模式对树形微波吸收元结构性能的影响。从材料层面来看,3D打印的ABS/CF/MWCNTs复合板的有效吸收带宽为5.16 GHz,厚度为3mm。此外,蚁群算法优化的仿生树形结构在厚度为10.8 mm时的有效吸收带宽高达11.5 GHz,在整个频率范围(2至18 GHz)内的最小反射损耗小于-9 dB。碳纤维增强复合材料增强的微波吸收元结构具有优异的抗拉强度和抗弯强度,平均抗拉强度和抗弯强度分别达到197.7 MPa和188.6 MPa。综上所述,本研究为微波吸波材料或结构的制备工艺优化提供了有价值的见解,为高性能吸波材料的设计和应用提供了科学依据。Damage-free Non-mechanical Transfer Strategy for Highly Transparent, Stretchable Embedded Metallic Micromesh ElectrodesZeqi Nie, Wenkai Yan, Xin Han, Huihuang Yu, Yapeng Zhang, Mengqi Tian, Xinyu Zhang, Yige Xiong, Peng Cao, Guanhua Zhangdoi:10.1016/j.compositesb.2024.111934 高透明、可拉伸嵌入式金属微孔电极的无损伤非机械转移策略Stretchable, flexible, transparent electrodes garner significant research interest as indispensable components of flexible optoelectronic devices. However, frequent mechanical transfers during processing pose a considerable challenge in preparing electrodes of scalable size with superior performance and intact structure. Herein, we present a stretchable embedded metallic micromesh (SEMM) electrode with high optoelectronic and robust mechanical properties. The SEMM electrode is fabricated via a damage-free non-mechanical transfer strategy with the assistance of a bifunctional metal transition layer that serves as both a seed layer during electrodeposition and a sacrificial layer during stripping of the electrode. Consequently, the SEMM electrode features a scalable size and an intact structure. By optimizing the electrodeposition parameters, the SEMM achieves high optical transmittance (∼83%) and low sheet resistance (0.22 Ω sq-1), with a figure of merit reaching 8600 – 53 times greater than that of commercial polyethylene terephthalate-indium tin oxide (PET-ITO). Furthermore, the SEMM exhibits excellent mechanical stability, enduring up to 60% of tensile strain and maintaining almost constant normalized resistance after 20,000 bending cycles. Based on the SEMM, a transparent film heater yields rapid response time, low operating voltage, and fast defogging capability. This non-mechanical transfer strategy offers a compelling approach for enhancing the structural integrity and scalability of stretchable embedded transparent electrodes.可拉伸、柔性、透明电极作为柔性光电器件不可或缺的组成部分,引起了人们极大的研究兴趣。然而,在加工过程中频繁的机械转移对制备具有优越性能和完整结构的可扩展尺寸的电极构成了相当大的挑战。在此,我们提出了一种具有高光电性能和强大机械性能的可拉伸嵌入金属微孔(SEMM)电极。在双功能金属过渡层的帮助下,通过无损伤的非机械转移策略制造SEMM电极,该过渡层在电沉积期间充当种子层,在电极剥离期间充当牺牲层。因此,SEMM电极具有可扩展的尺寸和完整的结构。通过优化电沉积参数,SEMM实现了高透光率(~ 83%)和低薄片电阻(0.22 Ω sq-1),其优点值比商用聚对苯二甲酸乙二醇酯-氧化铟锡(PET-ITO)高8600 - 53倍。此外,SEMM具有优异的机械稳定性,可承受高达60%的拉伸应变,并在20,000次弯曲循环后保持几乎恒定的归一化电阻。基于SEMM,透明薄膜加热器具有快速响应时间,低工作电压和快速除雾能力。这种非机械转移策略为增强可拉伸嵌入式透明电极的结构完整性和可扩展性提供了一种引人注目的方法。Composites Science and TechnologyRecyclable and highly thermally conductive nanocomposite with binary thermally conductive networks constructed from boron nitride nanoribbons and nanosheetsLiyuan Guo, Lei Feng, Caiyue Huang, Qiang Song, Peng Wei, Dongfang Xu, Mengdan Hou, Haojie Songdoi:10.1016/j.compscitech.2024.110954 由氮化硼纳米带和纳米片构成二元导热网络的可回收高导热纳米复合材料Technological advances have accelerated the development of high-performance insulation-based Thermal Interface Materials (TIMs), leading to increased generation of electronic waste. A significant challenge is the development of recyclable TIMs with superior thermal conductivity. Hemiaminal dynamic covalent network (HDCN) polymers are considered as an ideal matrix material for recyclable TIMs due to their high degradability at low pH (pH < 2). In this work, binary thermally conductive paths of hexagonal boron nitride nanoribbons (BNNRs) and boron nitride nanosheets (BNNSs) are introduced into the HDCN to improve the thermal conductivity of HDCN without sacrificing its electrically insulating properties. The functional BNNSs (f-BNNSs) are attached onto the surfaces of BNNRs to achieve the homogeneous distribution of nanosheets within the HDCN. Benefiting from the binary thermally conductive paths, an excellent in-plane thermal conductivity of 3.12 W·m-1K-1 for BNNS-BNNR/HDCN nanocomposite is achieved at a BN loading of 14 wt% (containing 2 wt% BNNRs and 12 wt% f-BNNS), increased by 1299% comparing to the pure HDCN polymer, as well as superior to those reported for polymer composites with similar loading of BNNRs or BNNSs. Additionally, the nanocomposite demonstrated efficient recyclability of BNNSs and BNNRs hybrid fillers in an acidic environment (pH < 2) at 25 °C with a recycling efficiency of 82%. Notably, the nanocomposite exhibited noteworthy electrical insulation properties. This study demonstrates the potential of BNNS-BNNR/HDCN as a recyclable TIMs and provides a new idea for the future research and development of recyclable high performance TIMs.技术进步加速了高性能绝缘热界面材料(TIMs)的发展,导致电子垃圾的产生增加。一个重大的挑战是开发具有优异导热性的可回收TIMs。半氨基动态共价网络(HDCN)聚合物由于其在低pH (pH < 2)下的高降解性被认为是可回收TIMs的理想基体材料。在本研究中,将六方氮化硼纳米带(BNNRs)和氮化硼纳米片(BNNSs)的二元导热路径引入HDCN中,以提高HDCN的导热性,同时又不牺牲HDCN的绝缘性能。功能化的BNNSs (f-BNNSs)附着在BNNRs的表面,实现了纳米片在HDCN内的均匀分布。得益于二元导热路径,BNNS-BNNR/HDCN纳米复合材料在BN负载为14 wt%(含2 wt% bnnr和12 wt% f-BNNS)时的面内导热系数为3.12 W·m-1K-1,比纯HDCN聚合物提高了1299%,也优于类似负载bnnr或bnns的聚合物复合材料。此外,该纳米复合材料在25°C的酸性环境(pH < 2)下具有BNNSs和BNNRs杂化填料的高效可回收性,回收率为82%。值得注意的是,纳米复合材料表现出显著的电绝缘性能。本研究证明了BNNS-BNNR/HDCN作为一种可回收的TIMs的潜力,为未来可回收的高性能TIMs的研究和开发提供了新的思路。来源:复合材料力学仿真Composites FEM

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