【新文速递】2023年12月25日固体力学SCI期刊最新文章

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

International Journal of Solids and Structures

Legendre-based node-dependent kinematics shell models for the global-local analysis of homogeneous and layered structures

E. Carrera, A. Pagani, D. Scano

doi:10.1016/j.ijsolstr.2023.112630

基于 Legendre 的节点运动学壳模型，用于均质结构和层状结构的全局-局部分析

The present work demonstrates the use of the node-dependent kinematics method to derive and compare several two-dimensional shell theories. The three dimensional displacement field is expressed in terms of generalized coordinates, which are subsequently expanded along the shell thickness using arbitrary functions. The in-plane unknowns, are then discretized through classical finite element approximation. Based on the Carrera Unified Formulation, the proposed method combines in a unique manner the theory of structures and the finite element method; thickness interpolation functions are defined node-wise. As a consequence, the resulting finite element model represents diverse approximation theories at each single node. In this work Taylor-based kinematics (including the Murakami Zig-Zag function) and Legendre-type nodal kinematics are incorporated at the element level without adopting mathematical artifices leading to the global-local strategy, where refined theories are selectively employed in specific areas, while maintaining acceptable computational costs. Numerical cases from the existing literature are employed to establish the effectiveness of node-dependent models in bridging a locally refined theories to global kinematics when local effects need to be considered. The analyses focus on localized loads for both homogeneous and multi-layered structures.

本研究展示了如何使用节点运动学方法来推导和比较几种二维壳体理论。三维位移场用广义坐标表示，然后用任意函数沿壳厚度展开。然后通过经典的有限元近似方法对平面内的未知量进行离散化。基于卡雷拉统一公式，所提出的方法以独特的方式结合了结构理论和有限元方法；厚度插值函数是按节点定义的。因此，由此产生的有限元模型在每个节点上都代表了不同的近似理论。在这项工作中，基于泰勒的运动学（包括村上之字形函数）和 Legendre 类型的节点运动学被纳入元素级，而不采用数学人工方法，从而实现了全局-局部策略，在保持可接受的计算成本的同时，在特定区域选择性地采用精炼理论。在需要考虑局部效应时，采用现有文献中的数值案例来确定节点相关模型在将局部细化理论与全局运动学相联系方面的有效性。分析的重点是均质结构和多层结构的局部载荷。

Mechanics of Materials

Bicrystallography-informed Frenkel–Kontorova model for interlayer dislocations in strained 2D heterostructures

Md Tusher Ahmed, Chenhaoyue Wang, Amartya S. Banerjee, Nikhil Chandra Admal

doi:10.1016/j.mechmat.2023.104903

应变二维异质结构中层间位错的双晶学信息 Frenkel-Kontorova 模型

In recent years, van der Waals (vdW) heterostructures and homostructures, which consist of stacks of two-dimensional (2D) materials, have risen to prominence due to their association with exotic quantum phenomena originating from correlated electronic states harbored by them. Atomistic scale relaxation effects play an extremely important role in the electronic scale quantum physics of these systems, providing means of manipulation of these materials and allowing them to be tailored for emergent technologies. We investigate such structural relaxation effects in this work using atomistic and mesoscale models, within the context of twisted bilayer graphene — a well-known heterostructure system that features moiré patterns arising from the lattices of the two graphene layers. For small twist angles, atomic relaxation effects in this system are associated with the natural emergence of interface dislocations or strain solitons, which result from the cyclic nature of the generalized stacking fault energy (GSFE), that measures the interface energy based on the relative movement of the two layers. In this work, we first demonstrate using atomistic simulations that atomic reconstruction in bilayer graphene under a large twist also results from interface dislocations, although the Burgers vectors of such dislocations are considerably smaller than those observed in small-twist systems. To reveal the translational invariance of the heterointerface responsible for the formation of such dislocations, we derive the translational symmetry of the GSFE of a 2D heterostructure using the notions of coincident site lattices (CSLs) and displacement shift complete lattices (DSCLs). The workhorse for this exercise is a recently developed Smith normal form bicrystallography framework. Next, we construct a bicrystallography-informed and frame-invariant Frenkel—Kontorova model, which can predict the formation of strain solitons in arbitrary 2D heterostructures, and apply it to study a heterostrained, large-twist bilayer graphene system. Our mesoscale model is found to produce results consistent with atomistic simulations. We anticipate that the model will be invaluable in predicting structural relaxation and for providing insights into various heterostructure systems, especially in cases where the fundamental unit cell is large and therefore, atomistic simulations are computationally expensive.

近年来，由二维（2D）材料堆叠而成的范德华（vdW）异质结构和同质结构因其与相关电子态所产生的奇异量子现象的联系而备受瞩目。原子尺度弛豫效应在这些系统的电子尺度量子物理中发挥着极其重要的作用，为操纵这些材料提供了手段，并使它们能够为新兴技术量身定制。扭曲双层石墨烯是一种著名的异质结构体系，其特征是两层石墨烯的晶格产生摩尔纹。对于较小的扭曲角度，该体系中的原子弛豫效应与界面位错或应变孤子的自然出现有关，而界面位错或应变孤子是广义堆积断层能（GSFE）的循环性质所致，GSFE 根据两层石墨烯的相对运动测量界面能量。在这项工作中，我们首先利用原子模拟证明了双层石墨烯在大扭转下的原子重构也是由界面位错引起的，尽管这种位错的布尔矢量比在小扭转系统中观察到的位错小得多。为了揭示导致这种位错形成的异质界面的平移不变性，我们利用重合位点晶格（CSL）和位移完全晶格（DSCL）的概念，推导出二维异质结构的 GSFE 的平移对称性。这项工作的主力是最近开发的史密斯正态双晶框架。接下来，我们构建了一个双晶体学信息和框架不变的 Frenkel-Kontorova 模型，该模型可以预测任意二维异质结构中应变孤子的形成，并将其应用于研究异质受限的大扭转双层石墨烯体系。研究发现，我们的中尺度模型得出的结果与原子模拟一致。我们预计，该模型在预测结构弛豫和深入了解各种异质结构体系方面将非常有价值，尤其是在基本单元尺寸较大，因此原子模拟计算成本较高的情况下。

Torsional waves in hyperelastic shells: Appearing shock waves and energy dissipation

Sergey V. Kuznetsov

doi:10.1016/j.mechmat.2023.104905

超弹性壳中的扭转波：冲击波的出现和能量耗散

Nonlinear torsional waves propagating in cylindrical shells made of hyperelastic material obeying Ogden model, are studied by a combined approach comprising theoretical and finite element analysis. It was found, apparently for the first time, that delta-like pulses of torsional waves attenuate with distance due to the appearance of shock wave fronts. Moreover, both strain and kinetic mechanical energy dissipate due to the release of thermal energy.

通过理论分析和有限元分析相结合的方法，研究了在符合奥格登模型的超弹性材料圆柱形壳体中传播的非线性扭转波。研究首次发现，由于冲击波前沿的出现，扭转波的三角脉冲随距离的增加而减弱。此外，由于热能的释放，应变和机械动能都会消散。

International Journal of Plasticity

Yield criterion for intergranular void coalescence under combined tension and shear

C. Sénac, J. Hure, B. Tanguy

doi:10.1016/j.ijplas.2023.103864

拉伸和剪切联合作用下晶粒间空隙凝聚的屈服准则

Intergranular ductile fracture is a failure mode that may arise in many metallic alloys used in industrial applications. It manifests as the successive nucleation, growth, and coalescence of cavities at grain boundaries. Thus, simulation of intergranular ductile fracture in polycrystals requires modeling those three different stages at the scale of grain boundaries, i.e. at the interface between two different crystals. In this study, a yield criterion for the coalescence of cavities at the interface between two isotropic materials obeying Mises plasticity is first developed by limit analysis in order to provide some insights into that phenomenon. This criterion is checked against numerical limit analysis under combined tension and shear and is found to agree with unit-cell simulations quantitatively. The model is then extended to crystals so as to account for the complex coupling between loading state, crystallographic orientations, and void microstructure in intergranular coalescence. This second criterion is also assessed through comparisons to numerical limit analysis for an FCC crystal lattice. The agreement is very good in the case of coalescence by internal necking and the trends displayed by coalescence under combined tension and shear are captured correctly. Some implications of the model on the competition between transgranular and intergranular ductile fracture are discussed. Finally, by combining this model with an existing criterion for void growth at grain boundaries, a multi-surface yield function relevant to intergranular ductile fracture is obtained and compared to unit-cell simulations.

晶间韧性断裂是工业应用中许多金属合金可能出现的一种失效模式。它表现为晶界处空洞的连续成核、生长和凝聚。因此，模拟多晶体中的晶间韧性断裂需要在晶界尺度（即两个不同晶体之间的界面）上对这三个不同阶段进行建模。在本研究中，首先通过极限分析建立了两个服从米塞斯塑性的各向同性材料界面处空穴凝聚的屈服准则，以便对这一现象提供一些见解。在联合拉伸和剪切的情况下，将该准则与数值极限分析进行检验，发现其在定量上与单细胞模拟一致。然后将模型扩展到晶体，以解释晶间凝聚中加载状态、晶体学取向和空隙微观结构之间的复杂耦合。第二个标准也通过与 FCC 晶格的数值极限分析进行比较来评估。在内部缩颈凝聚的情况下，两者的一致性非常好，并且正确捕捉到了拉伸和剪切联合作用下的凝聚趋势。此外，还讨论了该模型对跨晶和晶间韧性断裂竞争的一些影响。最后，通过将该模型与现有的晶界空隙增长准则相结合，获得了与晶间韧性断裂相关的多表面屈服函数，并与单元模拟进行了比较。

Thin-Walled Structures

Thermal conductivity and nonreciprocity in wrinkled monolayer graphene ring

Bohan Li, Qingxiang Ji, Jinliang Wang, Changguo Wang, Muamer Kadic

doi:10.1016/j.tws.2023.111523

皱褶单层石墨烯环的导热性和非互易性

We explore an external tunable approach to produce thermal nonreciprocity, by means of controlling wrinkle characteristics in graphene rings. The wrinkling formation and evolution law of graphene rings under torsional deformation is studied. Results show that wrinkle patterns of monolayer graphene can be flexibly tuned by controlling mechanical torsion. We further study the dependence of graphene rings’ thermal conductivity on sizes, temperatures and torsional angles, and reveal the influential mechanism by phonon density of states. Specifically, the thermal conductivity is reduced by 20.4% when the torsional angle increases from θ=0° to θ=10.3°. Finally, nonreciprocal conductive heat transfer is demonstrated in torsion-wrinkled graphene rings. It is found that thermal nonreciprocity effect is dependent on both torsional angles and temperature differences, i.e., the thermal nonreciprocity factor increase from 1.9% to 4.5% as temperature difference varies from 100K to 400K under torsional angle θ=6.9°. Our work paves new avenues for the design and implementation of thermal metadevices by mechanical tuning approach.

我们探索了一种通过控制石墨烯环的皱纹特性来产生热不折返性的外部可调方法。我们研究了石墨烯环在扭转变形下的皱纹形成和演变规律。结果表明，单层石墨烯的皱纹模式可以通过控制机械扭转进行灵活调整。我们进一步研究了石墨烯环的热导率与尺寸、温度和扭转角度的关系，并揭示了声子态密度的影响机制。具体来说，当扭转角从θ=0°增加到θ=10.3°时，导热率降低了 20.4%。最后，在扭转皱纹石墨烯环中演示了非互惠传导传热。研究发现，热非互惠效应与扭转角和温差都有关系，即在扭转角 θ=6.9° 时，当温差从 100K 变化到 400K 时，热非互惠因子从 1.9% 增加到 4.5%。我们的工作为利用机械调谐方法设计和实现热元器件开辟了新途径。

AXIAL COMPRESSIVE BEHAVIOR OF THE CHORD IN HYBRID FRP-CONCRETE-STEEL DOUBLE-SKIN TUBULAR MEMBER T-JOINTS

Guan Lin, Junjie Zeng, Jiaxing Li, G.M. Chen

doi:10.1016/j.tws.2023.111535

钢-混凝土混合结构双层管状构件 T 型接头弦杆的轴向受压行为

Hybrid fiber reinforced polymer (FRP)-concrete-steel double-skin tubular members (DSTMs) are a promising form of structural members with superior mechanical performance and durability, which have great potential for application in ocean structures. Such hybrid DSTMs consist of three components: an inner steel tube, an outer FRP tube, and concrete filled between the two tubes. Despite a significant number of studies demonstrating the excellent performance of hybrid DSTMs, no studies have been concerned with the joints of these members. The lack of a reliable design method for DSTM joints is certainly a huge obstacle to their wide application in practice. Against the above background, a research project has been proposed to understand the static behavior of circular DSTM T-joints through a combined experimental, modeling, and theoretical study. This paper presents the results of an experimental program on the axial compressive behavior of the chord in DSTM T-joints. The effects of various important factors, such as FRP tube thickness, steel tube thickness, brace-to-chord diameter ratio, void ratio, and concrete strength, on the performance of the DSTM T-joints were examined in detail. The test results demonstrated that the DSTM T-joints exhibited a ductile behavior provided that the joint region was appropriately strengthened and the presence of a brace did not significantly affect the compressive behavior of the chord in the joints with a brace-to-chord diameter ratio of 0.5. Finally, a simple method was proposed to predict the axial load-axial strain behavior of the DSTM T-joints.

混合纤维增强聚合物（FRP）-混凝土-钢双层管状构件（DSTM）是一种很有前途的结构构件形式，具有优异的机械性能和耐久性，在海洋结构中的应用潜力巨大。这种混合 DSTM 由三部分组成：内钢管、外玻璃钢管和填充在两根钢管之间的混凝土。尽管有大量研究表明混合 DSTM 性能卓越，但还没有研究涉及这些构件的连接问题。缺乏可靠的 DSTM 接头设计方法无疑是 DSTM 在实践中广泛应用的巨大障碍。在上述背景下，我们提出了一个研究项目，通过实验、建模和理论相结合的研究来了解圆形 DSTM T 型接头的静态行为。本文介绍了 DSTM T 型接头中弦杆轴向受压行为的实验结果。详细研究了玻璃钢管厚度、钢管厚度、支撑与弦直径比、空隙率和混凝土强度等各种重要因素对 DSTM T 型连接性能的影响。试验结果表明，DSTM T 型接头表现出延展性，前提是接头区域得到了适当的加固，并且在支撑与弦直径比为 0.5 的接头中，支撑的存在不会对弦杆的抗压性能产生显著影响。最后，提出了一种简单的方法来预测 DSTM T 型接头的轴向载荷-轴向应变行为。

Tailored twisted CNT bundle with improved inter-tube slipping performances

Danyang Zhao, Xing Quan Wang, Lik-ho Tam, Cheuk Lun Chow, Denvid Lau

doi:10.1016/j.tws.2023.111536

改进了管间滑移性能的定制扭曲碳纳米管束

The exceptional mechanical properties of carbon nanotubes (CNTs) have encouraged the development of high-performance synthetic fibers in composite materials. To understand the effect of twisting on the mechanical and slipping performances of CNT bundles, molecular dynamics simulation is applied to investigate the tensile performances, failure mode, and pull-out responses of twisted CNT bundles. A molecular model comprising nineteen parallel aligned single-walled carbon nanotubes (SWCNTs) is twisted into bundles at angles of 0°, 10°, and 20°, and further tensile and pull-out simulations are performed. The tensile simulation indicates that compared with the non-twisted CNT bundle showing a tensile strength of about 82 GPa with obvious inter-tube slipping, the 10°-twisted bundle exhibits a tensile strength of approximately 70 GPa with SWCNTs fracture as the main failure mode, which indicates that twisting improves the inter-tube slipping performance without causing excessive strength reduction. Comparatively, when the twisting angle is 20°, no inter-tube slipping is observed and the tensile strength of the CNT bundle is measured to be 55 GPa, which decreases by approximately 32.9 %. The pull-out simulations further reveal that the pull-out forces increase as the twisting angle increases and the weakened bundle strength of twisted bundle is attributed to the repulsive van der Waals forces caused by the reduced distances between inter-tubes. Essentially, twisting is unfavorable for the overall mechanical strength while torsional densification mitigates the inter-tube slipping, which indicates that a trade-off need to be achieved. This paper provides insights into the tensile and slipping performances of twisted CNT bundles and forms a basis for enhancing the assembled CNTs bundle as the next-generation reinforcing phase in composite materials.

碳纳米管（CNT）优异的机械性能促进了复合材料中高性能合成纤维的发展。为了解扭曲对碳纳米管束的机械和滑动性能的影响，本文应用分子动力学模拟研究了扭曲碳纳米管束的拉伸性能、失效模式和拉出响应。将由 19 根平行排列的单壁碳纳米管（SWCNT）组成的分子模型以 0°、10° 和 20°角扭曲成束，并进一步进行拉伸和拉出模拟。拉伸模拟结果表明，未扭转的 CNT 管束的拉伸强度约为 82 GPa，管间滑动明显，而扭转 10° 的管束的拉伸强度约为 70 GPa，SWCNT 断裂是主要的破坏模式。相比之下，当扭转角度为 20° 时，未观察到管间滑动，测得 CNT 束的抗拉强度为 55 GPa，降低了约 32.9%。拉拔模拟进一步表明，拉拔力随着扭转角度的增大而增大，扭转管束强度减弱的原因是管间距离减小导致的范德华排斥力。从根本上说，扭曲不利于整体机械强度，而扭转致密化则可减轻管间滑动，这表明需要权衡利弊。本文深入探讨了扭曲碳纳米管束的拉伸和滑移性能，为增强碳纳米管束的组装性能，将其作为复合材料的下一代增强相奠定了基础。

Characterization of low-velocity and low-energy responses of elastic-plastic plate struck by elastic-plastic impactor

Xin Xiao, Xiaochun Yin, Hui Wang, Huaiping Ding, Bo Yu, Yuanyuan Guo, Wenhao Xie

doi:10.1016/j.tws.2023.111537

弹性塑料板受弹性塑料撞击器撞击后的低速和低能响应特性分析

This paper presents a study on the characterization of low-velocity and low-energy impact responses of elastic-plastic plate struck by elastic-plastic spherical impactor. The applicability of the existing impact characterization diagram is examined firstly by intensive finite element (FE) simulations for a wide range of complicated impact situations including all three types of contact: indentation, flattening and combined flattening and indentation. The limitations of the existing diagram are found in identifying the type of impact response and predicting the maximum impact force for complicated impact situations. The effects of elastic and plastic deformations of impactor on the identification and prediction by the existing diagram are analyzed. A new linear contact law is presented according to the piecewise linear characteristics of contact stiffness observed from the intensive FE results. An extended impact characterization diagram is then proposed to characterize low-velocity and low-energy impact responses of plate under complicated impact situations with arbitrary three contact types. The extended diagram is validated by the intensive FE simulations and experimental results. It is concluded that the extended impact characterization diagram can identify correctly the plate response type to complicated impacts and predict accurately the maximum impact force in a fast and simple way without the aid of FE models and experimental tests.

本文研究了弹性塑料板在受到弹性塑料球形冲击器撞击时的低速和低能冲击响应特征。首先通过密集的有限元（FE）模拟，考察了现有撞击表征图的适用性，模拟了各种复杂的撞击情况，包括所有三种接触类型：压痕、压扁以及压扁和压痕组合。现有图表在确定冲击响应类型和预测复杂冲击情况下的最大冲击力方面存在局限性。分析了冲击器的弹性和塑性变形对现有图表识别和预测的影响。根据从强化 FE 结果中观察到的接触刚度的片状线性特征，提出了一种新的线性接触定律。然后提出了一个扩展的撞击特征图，以描述板材在任意三种接触类型的复杂撞击情况下的低速和低能撞击响应。强化 FE 仿真和实验结果对扩展图进行了验证。结论是，扩展的撞击特征图可以正确识别板材对复杂撞击的响应类型，并以快速、简单的方式准确预测最大撞击力，而无需借助有限元模型和实验测试。