【新文速递】2024年6月15日固体力学SCI期刊最新文章

 

今日更新：International Journal of Solids and Structures 1 篇，Journal of the Mechanics and Physics of Solids 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 5 篇

International Journal of Solids and Structures

Harnessing unconventional buckling of tube origami metamaterials based on Kresling pattern

Emilio Turco, Emilio Barchiesi, Andrea Causin, Francesco dell’Isola, Margherita Solci

doi:10.1016/j.ijsolstr.2024.112925

利用基于克瑞斯林模式的管状折纸超材料的非常规屈曲

Kresling tube metamaterials are well known to exhibit a chirality-dependent exotic mechanical feature: a shortening or lengthening in the direction of the tube’s axis produces a relative rotation of the two polygonal bases of the tube. This property can be easily grasped by fabricating a single-storey Kresling tube using cardboard. What has not been stressed much, if not even recognized, in the literature is the fact that such a mechanical feature is not depending only on the (chiral) geometrical pattern and unaffected by the in-plane/bending stiffness of facets and the creases’ resistance to folding. Assuming to neglect the bending stiffness of facets, in the present contribution we prove, through some numerical simulations based on a discrete model taking into account inertial terms, that only when the in-plane-to-folding stiffness ratio is large the Kresling tube exhibits the aforementioned exotic feature as described in the literature. We also prove that a low in-plane-to-folding stiffness ratio reveals: (i) an unconventional buckling mode, both for axial shortening and lengthening, which resembles the mechanism of a camera diaphragm; (ii) a kind of auxetic behaviour, i.e. a stenosis in a shortening test.

众所周知，克瑞斯林管超材料表现出一种与手性相关的奇异机械特性：在管轴方向上的缩短或延长会使管子的两个多边形基部产生相对旋转。利用硬纸板制作单层克雷斯林管，就能轻松掌握这一特性。文献中没有过多强调，甚至没有认识到的事实是，这种机械特性并不仅仅取决于（手性）几何图案，也不受切面的平面内/弯曲刚度和折痕抗折能力的影响。在本论文中，我们假定忽略刻面的弯曲刚度，通过一些基于离散模型的数值模拟并考虑惯性项，证明只有当平面内与折叠刚度比很大时，克雷斯林管才会表现出文献中描述的上述奇特特征。我们还证明，平面内与折叠刚度比小的情况下会出现：(i) 非传统的屈曲模式，无论是轴向缩短还是拉长，都类似于照相机膜片的机理；(ii) 一种辅助行为，即在缩短试验中出现狭窄。

Journal of the Mechanics and Physics of Solids

Derivation, characterization, and application of complete orthonormal sequences for representing general three-dimensional states of residual stress

Sankalp Tiwari, Eliot Fried

doi:10.1016/j.jmps.2024.105729

用于表示一般三维残余应力状态的完整正交序列的推导、表征和应用

Residual stresses are self-equilibrated stresses on unloaded bodies. Owing to their complex origins, it is useful to develop functions that can be linearly combined to represent any sufficiently regular residual stress field. In this work, we develop orthonormal sequences that span the set of all square-integrable residual stress fields on a given three-dimensional region. These sequences are obtained by extremizing the most general quadratic, positive-definite functional of the stress gradient on the set of all sufficiently regular residual stress fields subject to a prescribed normalization condition; each such functional yields a sequence. For the special case where the sixth-order coefficient tensor in the functional is homogeneous and isotropic and the fourth-order coefficient tensor in the normalization condition is proportional to the identity tensor, we obtain a three-parameter subfamily of sequences. Upon a suitable parameter normalization, we find that the viable parameter space corresponds to a semi-infinite strip. For a further specialized spherically symmetric case, we obtain analytical expressions for the sequences and the associated Lagrange multipliers. Remarkably, these sequences change little across the entire parameter strip. To illustrate the applicability of our theoretical findings, we employ three such spherically symmetric sequences to accurately approximate two standard residual stress fields. Our work opens avenues for future exploration into the implications of different sequences, achieved by altering both the spatial distribution and the material symmetry class of the coefficient tensors, toward specific objectives.

残余应力是未加载物体上的自平衡应力。由于其复杂的起源，开发可线性组合以表示任何足够规则的残余应力场的函数非常有用。在这项工作中，我们开发了正交序列，它涵盖了给定三维区域上所有可平方积分残余应力场的集 合。这些序列是通过对所有足够规则的残余应力场集 合上的应力梯度的最一般二次正定有限元函数进行极化而得到的，该极化需满足一个规定的归一化条件；每个这样的函数都会产生一个序列。对于函数中的六阶系数张量是均质和各向同性的，而归一化条件中的四阶系数张量与同一张量成比例的特殊情况，我们得到了一个三参数的序列子族。经过适当的参数归一化处理后，我们发现可行的参数空间对应于一个半无限条带。对于更特殊的球面对称情况，我们得到了序列和相关拉格朗日乘数的分析表达式。值得注意的是，这些序列在整个参数带中几乎没有变化。为了说明我们的理论发现的适用性，我们采用了三个这样的球面对称序列来精确逼近两个标准残余应力场。通过改变系数张量的空间分布和材料对称性类别，我们的工作为未来探索不同序列对特定目标的影响开辟了道路。

International Journal of Plasticity

High-cycle and low-cycle fatigue characteristics of multilayered dissimilar titanium alloys

Tianle Li, Wei Fan, Xifeng Li, Huiping Wu, Dayong An, Qi Hu, Jun Chen

doi:10.1016/j.ijplas.2024.104033

多层异种钛合金的高循环和低循环疲劳特性

Multilayered structures of dissimilar titanium alloys can achieve excellent fracture ductility and strength, while their fatigue characteristics especially dislocation networks and twin formation are rarely reported. Heterogeneous microstructures are observed in the multilayered TC4/TB8 alloys, including fine acicular α grains, continuous α layer at prior β grain boundaries (αGB) and β matrix on the TB8 layer, together with equiaxed α grains on the TC4 layer. High-cycle fatigue (HCF) and low-cycle fatigue (LCF) tests show that the initial fatigue damage appears at the αGB/β matrix interfaces on the TB8 layer instead of the boned TC4/TB8 interfaces. Since the stress concentration induced by dislocation pile-up is prone to micro-void formation and crack propagation at the αGB/β interfaces. For LCF, the αGB/β interfaces can not only act as impenetrable barriers and sources of lattice dislocations, but also allow the dislocations cross boundaries during cyclic tension and compression because of the high boundary energy. The formation characteristic of deformation twins that is beneficial for the plastic deformation of α grains in TC4 layer during cyclic strain is investigated. Furthermore, the hexagonal dislocation networks are also found within the equiaxed α grains of TC4 layer after LCF, and the role between interface barrier and slip direction in the formation mechanism is analyzed.

异种钛合金的多层结构可获得优异的断裂延展性和强度，但其疲劳特性，尤其是位错网络和孪晶形成却鲜有报道。在多层 TC4/TB8 合金中观察到了异质微观结构，包括细针状 α 晶粒、先于 β 晶界的连续 α 层（αGB）和 TB8 层上的 β 基体，以及 TC4 层上的等轴 α 晶粒。高循环疲劳（HCF）和低循环疲劳（LCF）试验表明，最初的疲劳损伤出现在 TB8 层上的 αGB/β 基体界面，而不是 TC4/TB8 的骨界面。由于位错堆积引起的应力集中容易在 αGB/β 接口处形成微空洞和裂纹扩展。对于 LCF 而言，αGB/β 界面不仅可以充当不可穿透的屏障和晶格位错源，而且在循环拉伸和压缩过程中，由于高边界能，位错还可以越界。研究了在循环应变过程中有利于 TC4 层中 α 晶粒塑性变形的变形孪晶的形成特征。此外，在 LCF 后，TC4 层等轴 α 晶粒内也发现了六方位错网络，并分析了界面屏障和滑移方向在形成机制中的作用。

Thin-Walled Structures

Seismic behaviour of reusable column base connection with pinned energy dissipators

MA Qi, CHAN Tak-Ming

doi:10.1016/j.tws.2024.112113

带有销钉消能装置的可重复使用柱基连接的抗震性能

A column base connection has been proposed to achieve reusability and self-centring after earthquakes. This proposed connection incorporates simple metallic yielding energy dissipators to effectively absorb seismic energy, while also employing pinned joints to facilitate the restoration of rocking behaviour in the column. To investigate the hysteretic behaviour of this innovative connection, a series of quasi-static tests were conducted on six groups of specimens. Among the parameters explored were the length, width, and limb number of the reduced section, activation angle, and material characteristics of the dissipative plate. During these experiments, the rocking mechanism was successfully demonstrated, and it was observed that the failure mode primarily involved concentrated plastic deformations of the dissipative plates. All of the specimens exhibited exceptional energy dissipation and self-centring capabilities. Furthermore, the repair process simply required the replacement of the damaged dissipative plates, which proved to be advantageous in terms of cost-effectiveness and efficiency. As a result, the repaired specimens regained their load-bearing ability and seismic performance to a comparable level as the original specimens. In the analysis of the test data, the changing patterns of dissipated energy, equivalent viscous damping ratio, and secant stiffness were determined in relation to the increasing target lateral displacement. The effects of various parameters on these aforementioned indexes were also preliminarily investigated. Additionally, based on the design concept, the relationship between moment and rotation angle of the column was described by an idealised curve. Consequently, the moment resistances of all test specimens were calculated, and the predicted results aligned well with the actual test results.

我们提出了一种柱基连接，以实现地震后的可重复使用性和自我集中。这种拟议的连接采用了简单的金属屈服消能装置来有效吸收地震能量，同时还采用了销钉连接来促进恢复柱子的摇晃行为。为了研究这种创新连接的滞后行为，对六组试样进行了一系列准静态试验。试验参数包括缩小截面的长度、宽度和肢数、激活角以及消能板的材料特性。在这些实验中，成功证明了摇摆机制，并观察到破坏模式主要涉及耗能板的集中塑性变形。所有试样都表现出卓越的消能和自聚能能力。此外，修复过程只需更换损坏的耗能板即可，这在成本效益和效率方面具有优势。因此，修复后的试样恢复了承载能力和抗震性能，达到了与原试样相当的水平。在对试验数据进行分析时，确定了随着目标侧向位移的增加，耗散能量、等效粘滞阻尼比和秒刚度的变化规律。还初步研究了各种参数对上述指标的影响。此外，根据设计理念，用理想化的曲线描述了支柱力矩与旋转角度之间的关系。因此，计算了所有试件的抗弯矩能力，预测结果与实际测试结果非常吻合。

Seismic design-assisted-by-testing approach for racks with dissipative baseplates in the cross-aisle direction

Bonaventura Tagliafierro, Rosario Montuori, Ioannis Vayas

doi:10.1016/j.tws.2024.112126

跨通道方向带耗散基板机架的抗震设计辅助测试方法

A design-assisted-by-testing strategy is proposed for the upright frames of adjustable pallet racks. The methodology defines a procedure that aims to locate marked post-elastic behavior at the floor-to-upright connections of lateral resisting frames in the cross-aisle direction. Such connections are intended to enhance the performance of the cross-aisle frames when subjected to dynamic forces in their plane. The chosen baseplateis experimentally tested using monotonic and cyclic protocols at the Steel Structures Laboratory of the National Technical University of Athens (Greece). Then, a numerical model of the baseplate is calibrated using literature parameter definitions and hence validated using physical data. Additionally, the dynamic response of two upright frames is numerically investigated: one with traditional hinge connections and another with dissipative ones. This study indicates that the proposed procedure successfully enhances ductility, resulting in a significant reduction (up to 50%) in upright axial forces compared to the conventional configuration. Finally, the open-source code for ground motion selection, together with its database, is released.

针对可调式托盘货架的直立框架提出了一种设计辅助测试策略。该方法定义了一个程序，旨在确定横向抗侧力框架的地板与直立框架连接处的明显后弹性行为。这种连接的目的是提高跨通道框架在其平面上受到动态力时的性能。希腊雅典国立技术大学钢结构实验室采用单调和循环协议对所选底板进行了实验测试。然后，利用文献中的参数定义对底板的数值模型进行校准，并利用物理数据进行验证。此外，还对两个直立框架的动态响应进行了数值研究：一个采用传统铰链连接，另一个采用耗散连接。研究结果表明，与传统结构相比，建议的程序成功地增强了延展性，使直立轴向力显著减少（最多减少 50%）。最后，发布了用于地面运动选择的开源代码及其数据库。

An adaptive modeling method with a local choice of optimal displacement fields for finite element analysis of structures

Guoqiang Wei, Jeanne Paroissien, Pascal Lardeur, Frédéric Druesne, Marc Oujdene

doi:10.1016/j.tws.2024.112129

结构有限元分析中局部选择最佳位移场的自适应建模方法

In the standard finite element procedure, the user chooses himself which mechanical theory will be used for a given application. To this end, he relies on some rules acquired through experience or some theoretical consideration. But choosing an appropriate theory may be a difficult task when geometry, boundary conditions, loadings, and materials are complex. This paper aims to define an adaptive methodology to identify, in the context of linear static analysis, optimal finite element models from a theory choice point of view. A criterion is defined to choose, in each part of the structure, the relevant mechanical theory: solid, shell or beam. A solid mesh is defined for the whole structure while specific solid-shell or solid-beam approaches are used in shell or beam areas respectively. This avoids the construction of mid-surface or mid-axis geometries from solid ones, which is a complicated task, in particular for industrial applications. Kinematic relations between nodes are imposed to apply the displacement fields of shell or beam theories. This leads to a set of linear equations which are used for eliminating slave degrees of freedom. The methodology proposed can also be interpreted as a model size reduction method, compared to a complete solid approach. The effectiveness of this approach is demonstrated through two numerical examples, including academic cantilever structures and an industrial multilayered composite structure.

在标准有限元程序中，用户自己选择在特定应用中使用哪种力学理论。为此，他要依靠从经验中获得的一些规则或一些理论考虑。但是，当几何形状、边界条件、载荷和材料非常复杂时，选择合适的理论可能是一项艰巨的任务。本文旨在定义一种适应性方法，在线性静态分析中，从理论选择的角度确定最佳有限元模型。本文定义了一个标准，用于在结构的每个部分选择相关的力学理论：实体、壳或梁。为整个结构定义实体网格，而在壳或梁区域分别采用特定的实体-壳或实体-梁方法。这就避免了从实体结构构建中表面或中轴几何结构的复杂工作，尤其是在工业应用中。在应用壳理论或梁理论的位移场时，节点之间存在运动学关系。这将产生一组线性方程，用于消除从属自由度。与完全实体方法相比，所提出的方法也可以解释为一种缩小模型尺寸的方法。通过两个数值示例，包括学术悬臂结构和工业多层复合结构，证明了这种方法的有效性。

Non-stationary response analysis for sandwich panels with corrugated cores under moving random loads

Bo Li, Dong Shao, Yongqiang Tao, Ningze Sun, Hong zhang

doi:10.1016/j.tws.2024.112131

带波纹芯材的夹芯板在移动随机载荷作用下的非稳态响应分析

In this work, a recursion reverberation-ray matrix method (RRRM) is presented to formulate an exact and unified solution for the non-stationary responses analysis of the sandwich panels with corrugated cores (SPCC) subjected to the moving random loads. The governing equations for the basic units are obtained by employing the simple first-order shear deformation theory (S-FSDT) and Hamilton's principle. Then, based on the traditional reverberation ray matrix method (MRRM), the RRRM is established by incorporating a bidirectional recursion technique to effectively calculate the exact solutions of the whole model. Thereinto, the kinematic relation matrix between the cell units can be constructed to facilitate the coupling of various desired numbers of elements by employing the virtual coupling spring. In addition, a unified loading mechanism for multi-scenario loads is proposed by integrating the pseudo-excitation method (PEM) with the load stage division technique. The applicability and accuracy of the current method to non-stationary response behaviors of the SPCC are clarified by carrying out sufficient comparative studies between the calculated results with reference solutions from FEM and Monte Carlo simulation method. Furthermore, several meaningful conclusions are drawn regarding the effects of structural and load parameters on the vibration characteristic, non-stationary displacement response, power spectrum density (PSD), and time-varying root mean square (RMS).

本研究提出了一种递归混响射线矩阵法（RRRM），为带波纹芯材的夹芯板（SPCC）在移动随机载荷作用下的非稳态响应分析提供了一种精确而统一的解决方案。利用简单一阶剪切变形理论（S-FSDT）和汉密尔顿原理获得了基本单元的控制方程。然后，在传统的混响射线矩阵法（MRRM）基础上，结合双向递归技术建立了 RRRM，从而有效地计算出整个模型的精确解。在此基础上，可以构建单元之间的运动关系矩阵，从而通过使用虚拟耦合弹簧，方便地耦合各种所需数量的元素。此外，通过将伪激振法（PEM）与载荷阶段划分技术相结合，提出了适用于多场景载荷的统一加载机制。通过将计算结果与有限元法和蒙特卡罗模拟法的参考解进行充分对比研究，阐明了当前方法对 SPCC 非稳态响应行为的适用性和准确性。此外，还就结构和载荷参数对振动特性、非稳态位移响应、功率谱密度（PSD）和时变均方根（RMS）的影响得出了一些有意义的结论。

Multiscale damage and low-velocity impact study of three-dimensional woven composites

Kunkun Jing, Hui Zhou, Hao Wang, Hongyu Yan, Suchao Xie

doi:10.1016/j.tws.2024.112132

三维编织复合材料的多尺度损伤和低速冲击研究

Three-dimensional woven composites address the limitation of weak interlaminar strength found in traditional laminated composites and offer superior resistance to out-of-plane impact. However, the complex material composition and structural intricacies necessitate investigation into their damage mechanisms. This study introduces novel and reliable microscale and mesoscale Representative Volume Element (RVE) models for three-dimensional woven composites, developed through advanced CT scanning and comprehensive multi-directional tensile and shear experiments. The research explores the impact of fiber volume fraction on yarn mechanical properties using the microscale RVE model, yielding precise macroscale homogenization parameters through the mesoscale RVE model. Furthermore, a macro-meso model tailored for low-velocity impact scenarios is established, significantly enhancing computational efficiency without compromising accuracy, thus providing support for further research on the impact properties of three-dimensional woven composites.

三维编织复合材料解决了传统层压复合材料层间强度较弱的局限性，并具有优异的抗平面外冲击能力。然而，由于材料成分复杂，结构错综复杂，有必要对其损伤机理进行研究。本研究通过先进的 CT 扫描和全面的多向拉伸和剪切实验，为三维编织复合材料引入了新颖可靠的微尺度和中尺度代表体积元素 (RVE) 模型。研究利用微观 RVE 模型探讨了纤维体积分数对纱线机械性能的影响，并通过中观 RVE 模型得出了精确的宏观均匀化参数。此外，还建立了针对低速冲击情景的宏观-中观模型，在不影响精度的前提下显著提高了计算效率，从而为进一步研究三维编织复合材料的冲击性能提供了支持。