【新文速递】2024年7月17日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 2 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 4 篇

International Journal of Solids and Structures

A minimalist elastic metamaterial with meta-damping mechanism

Yun-Long Chen, Li Ma

doi:10.1016/j.ijsolstr.2024.112977

具有超阻尼机制的极简弹性超材料

A novel elastic mechanical metamaterial with extreme damping performance has been achieved skillfully by coupling snap-through and pseudo-constant-force behaviors. The proposed meta-damping mechanism is systematically expounded to tailor synthetical force–displacement response for programming hyper energy dissipations. Within this framework, detailed designs in functional sub-structures and collaborative design strategy combined with parametric optimization in integrated structure are further presented synthetically. By additive manufacturing and loading–unloading cyclic experiments, the physical realization of meta-damping elastic metamaterials reveals the extraordinary specific damping capacity (Ψ=7.03), which exceeds any research reported previously and is immensely close to the theoretical limit. Remarkably, this minimalist design method, with only two necessary functional components, reconciles the contradiction between load-bearing and damping dissipation, with strong multi-directional and periodic expansibility. This work has far-reaching implications on the compact design of recoverability, reusability, frequency-independent, material-independent elastic mechanical metamaterials for superior dynamic applications such as impact absorption vibration reduction, and energy trapping.

一种新型弹性机械超材料通过耦合快穿和伪恒力行为，巧妙地实现了极强的阻尼性能。系统地阐述了所提出的元阻尼机制，以定制合成力-位移响应，实现超能量消耗编程。在此框架内，进一步综合介绍了功能性子结构的详细设计、协同设计策略以及集成结构的参数优化。通过增材制造和加载-卸载循环实验，元阻尼弹性超材料的物理实现揭示了非凡的特定阻尼能力（Ψ=7.03），这超出了之前的任何研究报告，并极大地接近理论极限。值得注意的是，这种简约的设计方法只需两个必要的功能组件，就能调和承重与阻尼耗散之间的矛盾，并具有很强的多向和周期扩展性。这项工作对紧凑设计可回收、可重复使用、与频率无关、与材料无关的弹性机械超材料具有深远影响，可用于冲击吸收、减震和能量捕获等卓越的动态应用。

A numerical study on tensile strength of low-density Kagome networks made of brittle fibers

Soham M. Mane, Kenneth M. Liechti, Rui Huang

doi:10.1016/j.ijsolstr.2024.112987

脆性纤维低密度Kagome网抗拉强度的数值研究

In this paper, we present a numerical study on the tensile strength of low-density Kagome networks made of brittle fibers. First, an elastic beam model is employed to analytically predict the effective elastic properties and tensile strength, as well as the critical condition for buckling of the fibers in Kagome networks. A series of finite element analyses are then conducted to simulate the elastic deformation and failure of Kagome networks under tension. The numerical results based on unit-cell models reveal four possible failure modes of the Kagome networks subject to uniaxial tension, summarized in a phase diagram in terms of the relative density and the fiber strength. The pre-buckling failure mode is restricted to cases with relatively high density and low fiber strength. A low-density Kagome network is likely to fail by one of the post-buckling modes, with an effective tensile strength much lower than the prediction by the elastic beam model. For Kagome networks consisting of a large number of unit cells, the effect of boundary conditions on the tensile strength is examined. Under periodic boundary conditions, the effective tensile strength is nearly identical to that predicted by the unit-cell model, independent of the model size. Under a roller boundary condition, with damage initiation near the free edges followed by a diffusive damage progression, the effective tensile strength is lower than that under periodic boundary conditions for the cases of relatively low fiber strengths. Under a clamped boundary condition, the effective tensile strength is higher than that under periodic boundary conditions for the cases of relatively high fiber strengths, where fiber buckling is largely suppressed by the clamped boundaries. Finally, the effect of a crack-like defect on the effective tensile strength is studied for Kagome networks under the clamped boundary condition. With a small defect, the effective strength is nearly independent of the defect size. In contrast, with a relatively long defect, the effective strength decreases almost linearly with the length of the crack-like defect. The effective toughness for damage initiation and steady-state damage progression in the Kagome networks are discussed from an energetic perspective.

本文对由脆性纤维制成的低密度Kagome网的抗拉强度进行了数值研究。首先，采用弹性梁模型对Kagome网络中纤维的有效弹性性能、抗拉强度及屈曲临界条件进行了分析预测。然后进行了一系列有限元分析，模拟了Kagome网在受拉作用下的弹性变形和破坏。基于单元胞模型的数值结果揭示了Kagome网络在单轴拉伸作用下的四种可能的破坏模式，并以相对密度和纤维强度的相图形式进行了总结。预屈曲破坏模式仅限于相对高密度和低纤维强度的情况。低密度Kagome网络可能因屈曲后模态之一而失效，其有效抗拉强度远低于弹性梁模型的预测。对于由大量单元格组成的Kagome网络，研究了边界条件对拉伸强度的影响。在周期性边界条件下，有效抗拉强度与单元胞模型预测的强度几乎相同，与模型尺寸无关。在滚动边界条件下，纤维强度相对较低时，纤维的有效抗拉强度低于周期性边界条件下的有效抗拉强度。在夹紧边界条件下，纤维强度较高的情况下，有效抗拉强度高于周期边界条件下的有效抗拉强度，在周期性边界条件下，纤维屈曲在很大程度上受到夹紧边界的抑制。最后，研究了在固支边界条件下，类裂纹缺陷对Kagome网络有效抗拉强度的影响。当缺陷较小时，有效强度几乎与缺陷尺寸无关。相反，当缺陷较长时，有效强度几乎随类裂纹缺陷的长度线性降低。从能量的角度讨论了Kagome网络损伤起裂和稳态损伤进展的有效韧性。

International Journal of Plasticity

Dual-phase polycrystalline crystal plasticity model revealing the relationship between microstructural characteristics and mechanical properties in additively manufactured maraging steel

Jakub Mikula, Guglielmo Vastola, Zhang Yong-Wei

doi:10.1016/j.ijplas.2024.104058

揭示增材马氏体时效钢组织特征与力学性能关系的双相多晶晶体塑性模型

To elucidate the relationship between microstructural characteristics and mechanical properties in additively manufactured (AM) maraging steel, this study introduces a computational approach that addresses two fundamental challenges. Firstly, it addresses the creation of representative volume elements (RVEs) that mimic the observed microstructural complexities, such as meltpool boundaries, prior austenite grains, packets and blocks of lath martensite. This is accomplished through the application of Potts Monte-Carlo methods and grain segmentation techniques in accordance with the Kurdjumov-Sachs orientation relationship. Secondly, this study develops a comprehensive crystal plasticity (CP) model encompassing both bcc and fcc plasticity. Inspired by atomistic and discrete dislocation dynamics studies, the proposed CP model incorporates characteristics intrinsic to bcc plasticity, including non-Schmid effects, dislocation and precipitate strengthening, and Hall-Petch type strengthening of elongated martensitic blocks. Utilizing the created RVEs and the proposed CP framework, finite element simulations are conducted based on an update-Lagrangian formulation. The purpose of this study is to investigate the deformation behavior, texture evolution, tension-compression asymmetry, and evolution in dislocation density in RVEs representative of as-built and heat-treated samples of maraging steel. This computational approach and its findings deepen our understanding of the intricate interplay between microstructural characteristics and mechanical properties in maraging steel and also provide valuable guidelines for refining its additive manufacturing and heat treatment processes.

为了阐明增材制造(AM)马氏体时效钢的微观组织特征和力学性能之间的关系，本研究引入了一种解决两个基本问题的计算方法。首先，它解决了模拟观察到的微观结构复杂性的代表性体积元素(RVEs)的创建，例如熔池边界，先前的奥氏体晶粒，板条马氏体的包和块。这是通过应用Potts蒙特卡罗方法和根据Kurdjumov-Sachs取向关系的颗粒分割技术来完成的。其次，本研究建立了包含bcc和fcc塑性的综合晶体塑性模型。受原子和离散位错动力学研究的启发，提出的CP模型结合了bcc塑性固有的特征，包括非施密德效应、位错和沉淀强化以及细长马氏体块体的Hall-Petch型强化。利用所创建的RVEs和所提出的CP框架，基于更新的拉格朗日公式进行了有限元模拟。本研究的目的是研究马氏体时效钢试样的变形行为、织构演变、拉压不对称性和位错密度的演变。这种计算方法及其发现加深了我们对马氏体时效钢微观结构特征和力学性能之间复杂相互作用的理解，也为改进其增材制造和热处理工艺提供了有价值的指导。

Thin-Walled Structures

Quantifying efficient shape-shifting: Energy barrier measurement in multi-stable lattice metamaterials

Qicheng Zhang, Jiajia Shen, Martin Garrad, Fabrizio Scarpa, Alberto Pirrera, Rainer M.J. Groh

doi:10.1016/j.tws.2024.112222

量化高效变形:多稳定晶格超材料中的能量势垒测量

Shape-shifting between multiple stable deformation states offers attractive pathways to design adaptive structures. Ideas have been conceptualised in diverse fields, including soft robotics and aerospace engineering. The success of shape-shifting relies on overcoming the energy barrier separating adjacent stable configurations, which necessitates efficient actuation strategies. Recently, multistable mechanical metamaterials have been designed with shape-shifting controlled by an actuator at the local scale, i.e with embedded actuation. This local, embedded actuation creates challenges for quantifying the energy barriers required for shape-shifting. Specifically, the local actuation requires a pair of forces with opposite directions and the direction of the forces must remain constant throughout the entire loading process. Moreover, the loading points must move freely in a direction perpendicular to the loading direction. We present a novel bi-axial test rig for a typical multi-stable lattice metamaterial that accurately determines the energy barrier between stable states by using an embedded actuator and inducing shape-shifting. Our experimental design features two independent actuation systems operating at different length scales: a primary one for a globally applied axial compression of the metamaterial, and a secondary local system for triggering shape-shifting between different stable configurations. Experimental data obtained using this bespoke test rig unveil the metamaterial’s response to local, embedded actuation. Excellent agreement with finite element simulations is observed, demonstrating the effectiveness of the test setup in providing measurements of the energy barrier. This work provides a valuable benchmark for measuring energy barriers in multi-stable metamaterials and paves the way for rigorous validation and verification of novel functional metamaterial and structures that leverage shape-shifting mechanisms.

多种稳定变形状态之间的形状转换为设计自适应结构提供了有吸引力的途径。包括软机器人和航空航天工程在内的各个领域都有概念化的想法。变形的成功依赖于克服分离相邻稳定构型的能量障碍，这就需要有效的驱动策略。近年来，多稳态机械超材料的变形被设计成由驱动器控制的局部尺度，即嵌入驱动器。这种局部的嵌入式驱动为量化变形所需的能量障碍带来了挑战。具体来说，局部驱动需要一对方向相反的力，并且在整个加载过程中力的方向必须保持恒定。此外，加载点必须在垂直于加载方向的方向上自由移动。我们提出了一种新型的双轴测试平台，用于典型的多稳定晶格超材料，该平台利用嵌入式致动器和诱导变形来精确地确定稳定状态之间的能量垒。我们的实验设计具有两个在不同长度尺度上运行的独立驱动系统:一个用于全局应用超材料轴向压缩的主驱动系统，以及一个用于触发不同稳定构型之间形状转换的次级局部驱动系统。使用这个定制的测试平台获得的实验数据揭示了超材料对局部嵌入式驱动的响应。与有限元模拟结果非常吻合，证明了测试装置在提供能量势垒测量方面的有效性。这项工作为测量多稳定超材料中的能量势垒提供了有价值的基准，并为利用变形机制的新型功能超材料和结构的严格验证和验证铺平了道路。

A novel single-DoF deployable antenna mechanism based on heterogeneous modules: Configuration design and performance analysis

Guoxing Zhang, Jie Wang, Jinwei Guo, Jianliang He, Yundou Xu, Yongsheng Zhao

doi:10.1016/j.tws.2024.112232

基于异构模块的新型单自由度可展开天线机构:结构设计与性能分析

The truss-type deployable antenna is the core equipment for information acquisition and transmission in aerospace engineering. As an important implementation method for large-aperture and high-precision space deployable antennas, the truss-type deployable antenna mechanism has advantages in surface accuracy, deployable ratio, and brace stiffness. However, existing parabolic deployable antennas based on isomorphic modules have shortcomings such as insufficient surface accuracy, complex actuation, and low deployable ratio. We propose a parabolic deployable antenna mechanism with single-DoF and deployable ratio, which combines research content such as parabolic reflector surface division, configuration synthesis, performance analysis and experimental verification of the deployable antenna mechanism. The research results indicate that the proposed mechanism has the characteristics of high surface accuracy, high deployable ratio, and single actuation. The research work provides a solid theoretical foundation and technical reserves for the application and research and development of high-precision and ultra large parabolic truss-type deployable antenna mechanisms.

桁架式可展开天线是航空航天工程中信息采集与传输的核心设备。桁架式可展开天线机构作为大口径高精度空间可展开天线的重要实现方式，在表面精度、可展开比、支撑刚度等方面具有优势。然而，现有的基于同构模块的抛物型可展开天线存在表面精度不足、驱动复杂、可展开比低等缺点。结合可展开天线机构的抛物面划分、构型综合、性能分析和实验验证等研究内容，提出了一种单自由度、可展开比的抛物面可展开天线机构。研究结果表明，该机构具有高表面精度、高展开比、单驱动等特点。研究工作为高精度、超大型抛物桁架式可展开天线机构的应用和研发提供了坚实的理论基础和技术储备。

Fire resistance and stability of non-uniformly heated steel plate girders with slender section

Piotr Woźniczka

doi:10.1016/j.tws.2024.112234

细长截面非均匀加热钢板梁的耐火性与稳定性

The results of experimental tests and computer simulations pertaining to the bearing capacity of unevenly heated girders made of slender thin walled class 4 sections are presented in this paper. It has been shown, that for the analyzed group of elements the value of lateral-torsional buckling coefficient depends on the initial load level applied to the considered element and the cross section bearing capacity reduction level under fire conditions. It has been determined as well that the influence of steel grade used on the value of buckling coefficient is negligible. Based on the research conducted, a new proposal for calculation of the lateral-torsional buckling coefficient for considered group of elements has been prepared. A simplified method to determine the bearing capacity of non-uniformly heated class 4 sections is proposed in this paper as well. It has been shown that both proposed methods exhibit sufficient convergence of results with the results of computer simulations, and satisfy appropriate acceptance criteria as well.

本文介绍了4级薄壁细长截面不均匀加热梁的承载力试验和计算机模拟结果。结果表明，对于所分析的单元组，侧扭屈曲系数的取值取决于所考虑单元的初始荷载水平和火灾条件下截面承载力的降低水平。结果表明，钢种对屈曲系数的影响可以忽略不计。在此基础上，提出了计算考虑单元群侧扭屈曲系数的新方案。本文还提出了一种确定非均匀加热4类截面承载力的简化方法。结果表明，这两种方法的计算结果与计算机模拟结果具有足够的收敛性，并满足适当的接受准则。

Spectro-Geometry dynamic analysis of FG-GPLRC cylindrical shell with periodically embedded dynamic vibration absorbers

Haochen Hu, Rui Zhong, Qingshan Wang, Xianjie Shi

doi:10.1016/j.tws.2024.112243

FG-GPLRC周期性内嵌动力吸振器圆柱壳的光谱几何动力学分析

This study presents a theoretical model of the functionally graded graphene platelet-reinforced composite (FG-GPLRC) cylindrical shell with periodically embedded dynamic vibration absorbers (DVAs) under different boundary constraints. The material parameters of the FG-GPLRC were first determined using the Halpin-Tsai micromechanical method and the general law of mixing. The energy expression for the system is developed based on the first-order shear deformation theory (FSDT). A simplified model of the DVA is carried out, which consists of a mass block, a linear damper and a linear spring after simplification. Displacement field vectors of the cylindrical shell are established based on the spectro-geometric method (SGM). The Rayleigh-Ritz method was used to determine the vibration response of the coupled model. The validity of the proposed method is confirmed through comparing with results from existing literature and finite element method (FEM) calculations. The effect of boundary conditions, FG-GPLRC material properties, geometrical parameters of cylindrical shells, distribution parameters of DVAs, and damping coefficient on the steady-state vibration of the coupled model is investigated on this basis.

本文建立了不同边界约束下具有周期性内嵌动态吸振器的功能梯度石墨烯平板增强复合材料(FG-GPLRC)圆柱壳的理论模型。首先采用Halpin-Tsai微力学方法和混合一般规律确定了FG-GPLRC的材料参数。基于一阶剪切变形理论(FSDT)建立了系统的能量表达式。建立了由质量块、线性阻尼器和线性弹簧组成的DVA简化模型。基于光谱几何方法建立了圆柱壳的位移场矢量。采用瑞利-里兹法确定了耦合模型的振动响应。通过与已有文献和有限元计算结果的比较，验证了所提方法的有效性。在此基础上，研究了边界条件、FG-GPLRC材料性能、圆柱壳几何参数、DVAs分布参数和阻尼系数对耦合模型稳态振动的影响。