【新文速递】2023年11月10日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 3 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 4 篇International Journal of Solids and StructuresA semi-analytical approach for two-dimensional frictional contact of anisotropic magneto-electro-elastic solidsNguyen Van Thuong, Bui Tinh Quocdoi:10.1016/j.ijsolstr.2023.112565各向异性磁-电弹性固体二维摩擦接触的半解析方法In this work, we present a semi-analytical modeling approach for solving the frictional contact of two-dimensional anisotropic magneto-electro-elastic (MEE) solids. The method is established in a broad framework in which the contact body is made of generally anisotropic MEE materials, the punch head can be arbitrary, and the punch can be subjected to generalized loading conditions including mechanical forces and electric and magnetic charges. An analytical solution of generalized distributed load along the half-plane surface is derived and utilized to formulate the semi-analytical equations governing the relation between the generalized displacements and tractions. Based upon the semi-analytical equations, the semi-analytical model in which the influence matrices can be calculated explicitly and its effectiveness is established. An iterative procedure is then used for determining the contact region, contact status, generalized surface deformation and the distribution of contact tractions, as well as the punch’s indentation depth and electric and magnetic potentials. The present approach is verified by comparing its numerical results with those obtained by the existing analytical solutions and boundary element method. The influences of different factors, such as punch profile, mechanical load, electric and magnetic charges, friction coefficient and material properties, are also analyzed. The capability of this method to handle complicated geometry, such as rough surfaces, is finally discussed, showing the potential performance of the developed method for practical engineering applications.在这项工作中，我们提出了一种求解二维各向异性磁电弹性(MEE)固体摩擦接触的半解析建模方法。该方法建立在一个广泛的框架中，其中接触体通常由各向异性的MEE材料制成，冲头可以是任意的，并且冲头可以承受包括机械力和电荷和磁荷在内的广义加载条件。推导了沿半平面的广义分布荷载的解析解，并利用该解析解建立了广义位移与牵引力关系的半解析方程。在半解析方程的基础上，建立了能显式计算影响矩阵的半解析模型，并证明了该模型的有效性。然后使用迭代程序确定接触区域、接触状态、广义表面变形和接触牵引力的分布，以及冲床的压痕深度和电势和磁势。通过与现有解析解和边界元法的数值结果对比，验证了本文方法的正确性。分析了冲头外形、机械载荷、电荷和磁荷、摩擦系数和材料性能等因素对冲头成形的影响。最后讨论了该方法处理复杂几何形状(如粗糙表面)的能力，显示了该方法在实际工程应用中的潜在性能。Micromechanics of kink-band formation in bimetallic layered compositesRathod Hemant J., Bin Asim Umair, Radovic Miladin, Srivastava Ankitdoi:10.1016/j.ijsolstr.2023.112566双金属层状复合材料中扭结带形成的微观力学Bimetallic layered composites with ultrathin layers possess high strength and hardness, excellent shock resistance, and radiation damage tolerance. However, they are prone to deformation localization and readily form kink-bands when subjected to layer parallel compression. Following this, we carried out extensive plane strain finite element finite deformation analyses to understand and rationalize the experimentally observed kink-band formation in these composites. In the calculations, both constituent materials were assumed to follow a rate-independent isotropic elastic-plastic constitutive relation with an ad-hoc thickness dependent yield strength. Our results demonstrate that in these composites, layer refinement, together with the strength differential between the layers of the constituent materials, is sufficient to trigger kink-banding. Importantly, this phenomenon occurs even in the absence of elastically stiff layers, geometrical imperfections (such as waviness of the layers), and extreme plastic anisotropy within the layers. Additionally, we performed parametric studies to investigate the individual effects of layer thickness, strength differential between the two constituent materials, and strain-hardenability of the materials on kink-band formation. The outcomes of our parametric studies reveal that the strain-hardenability of the constituent materials stabilizes the formation of kink-bands. Furthermore, it leads to a transition from the abrupt formation of through-width kink-bands to the onset and propagation of stable inclined wedge-shaped kink-bands, similar to the experimental observations.具有超薄层的双金属层状复合材料具有高强度、高硬度、优异的抗震性和耐辐射损伤能力。然而，当受到层平行压缩时，它们容易变形局部化，容易形成扭结带。随后，我们进行了广泛的平面应变有限元有限变形分析，以理解和合理化实验观察到的这些复合材料中的扭结带形成。在计算中，假设两种成分材料遵循速率无关的各向同性弹塑性本构关系，并具有特定的厚度依赖屈服强度。我们的研究结果表明，在这些复合材料中，层细化以及组成材料层之间的强度差异足以触发扭结带。重要的是，即使在没有弹性刚性层、几何缺陷(如层的波浪形)和层内极端塑性各向异性的情况下，这种现象也会发生。此外，我们进行了参数研究，以调查层厚度、两种成分材料之间的强度差异以及材料的应变淬透性对扭结带形成的个别影响。我们的参数研究结果表明，组成材料的应变淬透性稳定了扭结带的形成。此外，与实验观察结果相似，它导致了从贯穿宽度扭结带的突然形成到稳定倾斜楔形扭结带的开始和传播的转变。A variational approach to effective models for inelastic systemsJezdan Ghina, Govindjee Sanjay, Hackl Klausdoi:10.1016/j.ijsolstr.2023.112567非弹性系统有效模型的变分方法Given a set of inelastic material models, a microstructure, a macroscopic structural geometry, and a set of boundary conditions, one can in principle always solve the governing equations to determine the system’s mechanical response. However, for large systems this procedure can quickly become computationally overwhelming, especially in three-dimensions when the microstructure is locally complex. In such settings multi-scale modeling offers a route to a more efficient model by holding out the promise of a framework with fewer degrees of freedom, which at the same time faithfully represents, up to a certain scale, the behavior of the system. In this paper, we present a methodology that produces such models for inelastic systems upon the basis of a variational scheme. The essence of the scheme is the construction of a variational statement for the free energy as well as the dissipation potential for a coarse scale model in terms of the free energy and dissipation functions of the fine scale model. From the coarse scale energy and dissipation we can then generate coarse scale material models that are computationally far more efficient than either directly solving the fine scale model or by resorting to FE 2 type modeling. Moreover, the coarse scale model preserves the essential mathematical structure of the fine scale model. An essential feature for such schemes is the proper definition of the coarse scale inelastic variables. By way of concrete examples, we illustrate the needed steps to generate successful models via application to problems in classical plasticity, included are comparisons to direct numerical simulations of the microstructure to illustrate the accuracy of the proposed methodology.给定一组非弹性材料模型、微观结构、宏观结构几何和一组边界条件，原则上总是可以求解控制方程来确定系统的力学响应。然而，对于大型系统，这个过程很快就会变得难以计算，特别是在三维结构局部复杂的情况下。在这种情况下，多尺度建模提供了一条通往更有效模型的途径，它提供了一个具有更少自由度的框架的承诺，同时忠实地代表了系统的行为，达到一定的尺度。在本文中，我们提出了一种方法，在变分方案的基础上为非弹性系统产生这样的模型。该方案的实质是用细尺度模型的自由能和耗散函数构造粗尺度模型的自由能和耗散势的变分表达式。从粗尺度的能量和耗散，我们可以生成粗尺度的材料模型，其计算效率远远高于直接求解细尺度模型或诉诸fe2型建模。此外，粗比例尺模型保留了精细比例尺模型的基本数学结构。这种方案的一个基本特征是适当地定义粗尺度非弹性变量。通过具体的例子，我们说明了通过应用经典塑性问题生成成功模型所需的步骤，包括与微观结构的直接数值模拟的比较，以说明所提出方法的准确性。Mechanics of MaterialsA theoretical model for the prediction of fracture process zone in concrete under fatigue loading: Energy based approachKumar Bineet, Dubey Sandeep, Ray Sonalisadoi:10.1016/j.mechmat.2023.104850疲劳荷载作用下混凝土断裂过程区预测的理论模型:能量法Characterizing the fracture behaviour of concrete and accurately predicting its service life under fatigue loading pose a significant challenge due to its heterogeneous nature and complex fracture mechanisms. The proposed study focuses on developing an energy based theoretical formulation for predicting the evolution of the fracture process zone throughout repetitive loading cycles. A stiffness degradation approach has been adopted for developing the formulations for the critical energy dissipation and fully developed fracture process zone. Subsequently, the proposed analytical expressions have been calibrated and validated by performing experiments under centre point bending and using available experimental results in the literature. Experiments have been conducted on a centre-point bend beam with varying aggregate size in conjunction with the digital image correlation (DIC) technique to estimate the fracture characteristics. The influence of specimen size and heterogeneity has been discussed in the context of predicting the fracture behaviour, critical dissipated energy, and process zone length of plain concrete beam specimens under fatigue loading. The results indicate that the process zone length and critical energy release rate increase with an increase in specimen size, while the same decreases with an increase in aggregate size由于混凝土的非均质性和复杂的断裂机制，表征其在疲劳荷载作用下的断裂行为并准确预测其使用寿命是一项重大挑战。提出的研究重点是开发一种基于能量的理论公式，用于预测在重复加载周期中断裂过程区的演变。采用刚度退化的方法建立了临界能量耗散和完全发育断裂过程区的计算公式。随后，通过在中心点弯曲下进行实验并使用文献中可用的实验结果，对所提出的解析表达式进行了校准和验证。结合数字图像相关(DIC)技术，对具有不同骨料尺寸的中心点弯曲梁进行了断裂特征估计实验。在预测素混凝土梁试件在疲劳荷载作用下的断裂行为、临界耗散能和过程区长度时，讨论了试件尺寸和非均质性的影响。结果表明:过程区长度和临界能量释放率随试样尺寸的增大而增大，随骨料尺寸的增大而减小International Journal of PlasticityImpact resistance and energy dissipation mechanism of nanocrystalline CoCrNi medium entropy alloy nanofilm under supersonic micro-ballistic impactDong J.L., Li F.C., Gu Z.P., Jiang M.Q., Liu Y.H., Wang G.J., Wu X.Q.doi:10.1016/j.ijplas.2023.103801 超声速微弹道冲击下纳米晶CoCrNi中熵合金纳米膜的抗冲击性能及能量耗散机制A fundamental understanding of the mechanical behavior of materials subjected to dynamic loading is critical for developing outstanding structural materials. In this paper, we used laser-induced high-velocity (500 ∼ 800 m/s) micro-projectile impact experiments to measure the impact response of 100 nm thick CoCrNi medium entropy alloy (MEA) nanofilm. The results revealed that the CoCrNi MEA nanofilm exhibits high specific penetration energy (up to 0.882 MJ/kg−1) and excellent impact resistance, significantly surpassing traditional protective materials. The specific penetration energy of CoCrNi MEA nanofilm is approximately 1.8 to 2.2 times that of steel and 1.2 to 1.4 times that of Kevlar composite plates. Based on the post-impact analysis, we observed abundant energy dissipation pathways including multiple cracks, bending of cracking-induced petals, mechanical twins, and, of particular note, amorphization for the nanocrystalline CoCrNi MEA nanofilm. Such solid-state amorphization stemming from severe lattice distortion activates a new mechanism for impact energy dissipation. The versatility and synergy of these deformation mechanisms contribute to the exceptional protective performance of the nanocrystalline CoCrNi MEA nanofilms. The specific penetration energy of the nanocrystalline CoCrNi MEA nanofilm is about 21% higher compared to that of the amorphous CoCrNi MEA nanofilm due to the additional energy dissipation mechanisms arising from mechanical twins and amorphization. This study provides valuable physical insights into the impact resistance and energy dissipation mechanisms of MEA nanofilm and highlights its potential as a high-performance coating to enhance the surface integrity and reliability of equipment subjected to high-speed collisions of solid particles.对动态载荷下材料力学行为的基本理解对于开发优秀的结构材料至关重要。本文采用激光诱导的高速(500 ~ 800 m/s)微弹冲击实验，测量了100 nm厚CoCrNi介质熵合金(MEA)纳米膜的冲击响应。结果表明，CoCrNi MEA纳米膜具有较高的比穿透能(高达0.882 MJ/kg−1)和优异的抗冲击性能，明显优于传统的防护材料。CoCrNi MEA纳米膜的比穿透能约为钢的1.8 ~ 2.2倍，凯夫拉复合材料板的1.2 ~ 1.4倍。基于冲击后分析，我们观察到丰富的能量耗散途径，包括多重裂纹、裂纹诱导花瓣弯曲、机械孪晶，以及特别值得注意的CoCrNi MEA纳米膜的非晶化。这种由严重晶格畸变引起的固态非晶化激活了一种新的冲击能量耗散机制。这些变形机制的多功能性和协同性有助于纳米晶CoCrNi MEA纳米膜的特殊保护性能。由于机械孪晶和非晶化产生的额外能量耗散机制，纳米晶CoCrNi MEA纳米膜的比穿透能比非晶CoCrNi MEA纳米膜高21%左右。该研究为MEA纳米膜的抗冲击性和能量耗散机制提供了有价值的物理见解，并突出了其作为高性能涂层的潜力，可以提高设备在高速固体颗粒碰撞下的表面完整性和可靠性。Thin-Walled StructuresNonreciprocal Wave Propagation in a Time-Space Modulated Metasurface using the Modified Plane Wave Expansion MethodKargozarfard Mohammad Hassan, Sedighi Hamid M., Yaghootian Amin, Valipour Alidoi:10.1016/j.tws.2023.111335基于改进平面波展开法的时空调制超表面中非互易波传播The present work focuses on the impact of including the time-space modulation features on the band structure. This study introduces a modified plane wave expansion method for dealing with the out-of-plane wave propagation in a two-dimensional periodic metasurface. The proposed method, which is applied to structures with modulated properties, tackles the constraints of the conventional plane wave method. The characteristics of uncommon systems with space-time-variant properties are explored by analyzing the produced dispersion curves by modified plane wave method. This approach can also resolve the inconsistencies and drawbacks of other similar approaches. Three scenarios are employed to extract the patterns of bandgap regions and discover the impact of time-traveling material features on the creation of bandgap in periodic metasurfaces. The integrity of the introduced method has been established by comparison with data obtained from COMSOL finite element software as well as the reported results in the literature. The secondary objective of this study is to manipulate the location of the bandgap to achieve complete control over the propagation of waves. The effectiveness of the proposed approach becomes more apparent when applied to metamaterials that incorporate piezoelectric materials with discrete structures. This relates primarily to enhanced precision and speed, particularly in higher modes and sheds light on a potential application of extending this scenario to the more complex structures.本文主要研究了加入时空调制特性对波段结构的影响。提出了一种改进的平面波展开法，用于处理二维周期超表面的面外波传播。该方法适用于具有调制特性的结构，解决了传统平面波方法的局限性。通过对修正平面波法产生的色散曲线的分析，探讨了具有时空变性质的非常见系统的特性。这种方法还可以解决其他类似方法的不一致性和缺点。采用三种场景提取带隙区域的模式，并发现时间旅行材料特性对周期性超表面带隙产生的影响。通过与COMSOL有限元软件数据和文献报道结果的比较，证实了所提方法的完整性。本研究的第二个目标是操纵带隙的位置，以实现对波传播的完全控制。当应用于包含离散结构的压电材料的超材料时，所提出的方法的有效性变得更加明显。这主要与提高精度和速度有关，特别是在更高的模式下，并揭示了将这种情况扩展到更复杂结构的潜在应用。Exploring the three-dimensional space with modular concrete shells: Form-finding, design and structural analysisDe Coster Arnaud, De Laet Lars, Tysmans Tinedoi:10.1016/j.tws.2023.111336用模块化混凝土外壳探索三维空间:寻找形式、设计和结构分析Thin concrete shells can span large distances thanks to their structural efficiency, following the optimum force flow. Despite the efficient use of material of well-designed shells, their construction suffers from labor-intensive and time-consuming fabrication techniques. This research therefore proposes a design method for the facilitated manufacturing of freeform shell structures. The manufacturing process has been considered from the design phase on, by generating an extensive range of different shell configurations based on a limited set of form-found modules and thus formworks. The challenge was to define which curved module geometries, after assembly, lead to the largest variety of freeform surfaces. More than sixty configurations resulted from a set of four modules only. This paper will discuss the form-finding process as well as the geometrical arrangement using tessellation patterns for the achievement of those modular configurations, going from domed to undulating shell shapes. In order to evaluate the structural efficiency of the shapes, twenty modular configurations were selected and analyzed under self-weight, using finite element simulations. To conclude, a prototype of one modular base element has been built, using a reusable casting wax in combination with a grid shell box, as the main parts of the formwork. The results demonstrate the structural feasibility and limitations of the modular shell design strategy. The modular approach contributes to circularity by encouraging reuse and allowing various combinations with a repeating set of modules, striving as such towards resource-effective innovative shell structures.由于其结构效率，薄混凝土壳可以跨越很远的距离，遵循最佳的力流。尽管有效地利用了精心设计的外壳材料，但它们的建造受到劳动密集型和耗时的制造技术的影响。因此，本研究提出了一种易于制造自由形式壳体结构的设计方法。制造过程从设计阶段就开始考虑，通过基于有限的形式发现模块和模板生成广泛的不同外壳配置。挑战在于确定装配后哪种弯曲模块几何形状可以产生最大种类的自由曲面。仅一组四个模块就产生了60多个配置。本文将讨论找形过程以及使用镶嵌图案实现这些模块化配置的几何排列，从圆顶到起伏的外壳形状。为了评估形状的结构效率，选择了20种模块化配置，并在自重下进行了有限元模拟分析。总而言之，一个模块化基础元素的原型已经建成，使用可重复使用的铸造蜡与网格壳盒相结合，作为模板的主要部分。结果表明了模块化壳体设计策略在结构上的可行性和局限性。模块化方法通过鼓励重用和允许与重复模块集的各种组合来促进循环，努力实现资源有效的创新外壳结构。Asymptotically correct 3D displacement of the Mooney-Rivlin model using VAMBhadoria Shravan Kumar, Gupta Burela Rameshdoi:10.1016/j.tws.2023.111358用VAM对Mooney-Rivlin模型的三维位移进行渐近校正The current work focuses on the nonlinear analytical analysis (dimensional reduction and recovery relations) of a hyperelastic plate governed by the compressible Mooney-Rivlin model using the Variational Asymptotic Method (VAM). The geometric nonlinearity is accommodated through finite deformations, and generalized 3D warping functions, while material nonlinearity through the hyperelastic material model. VAM mathematically splits the 3D nonlinear elastic problem into the 1D through the thickness analysis and 2D nonlinear plate analysis, using the inherent small parameters. These are the geometric small parameter (ratio of thickness to the characteristic dimension), and the physical small parameter (moderate strains). This work results include the derivation of closed-form analytical expressions of 3D warping functions, 2D nonlinear constitutive relation, and recovery relation to express the 3D displacement field for a plate. The 2D nonlinear constitutive relation is given as an input to the in-house developed 2D nonlinear finite element analysis of the reference surface to determine the 2D displacements and 2D strains. In order to validate the current theory, standard test cases are solved and compared with 3D nonlinear Finite Element Analysis (FEA).本文利用变分渐近方法(VAM)研究了可压缩Mooney-Rivlin模型下超弹性板的非线性解析分析(降维关系和恢复关系)。几何非线性通过有限变形和广义三维翘曲函数来调节，而材料非线性通过超弹性材料模型来调节。VAM利用固有的小参数，通过厚度分析和二维非线性板分析，在数学上将三维非线性弹性问题分解为一维。这些是几何小参数(厚度与特征尺寸的比值)和物理小参数(中等应变)。本文的研究成果包括导出三维翘曲函数的封闭解析表达式、二维非线性本构关系和恢复关系来表示板的三维位移场。给出二维非线性本构关系作为内部开发的二维非线性有限元参考面分析的输入，以确定二维位移和二维应变。为了验证现有理论，求解了标准测试用例，并与三维非线性有限元分析(FEA)进行了比较。The modified force density method for form-finding of cable net structureLi Xiongyan, Liu Caibao, Xue Suduo, Li Xuanzhi, Zhang Cong, Huang Liyoudoi:10.1016/j.tws.2023.111363修正力密度法在索网结构找形中的应用Form-finding is crucial for the design of typical cable net structures. Based on the original basic force density method, a modified force density method utilizing the concept of relation matrix is proposed in this paper. The modified method realizes the establishment of a clear correspondence between members and nodes of cable net structures. On the basis of the relation matrix, the find function is introduced, and the calculation formula of the modified branch-node matrix is derived. Meanwhile, the corresponding analysis steps and calculation process are given. The modified method is verified by the analysis of representative structural forms. The results show that for the saddle-shaped orthogonal cable net structure, the outcomes obtained from the modified force density method highly agree with the theoretical values, providing preliminary verification of the method's effectiveness. For single-layer spoke cable net structures, the relative error between the results calculated by the modified force density method and the numerical solution is approximately 5 %. The results of both methods are relatively consistent, and the relative error varies in relation to the ratio of inner ring cable force density to radial cable force density. For circular single-layer crossed cable net structure without inner ring, the results of the modified force density method are very close to the numerical solution. The maximum relative error between the two is 6.95 %, and the accuracy is higher than that of the nonlinear finite element method. The outcome of this research demonstrates the accuracy of the modified force density method and its effective application in the form-finding of actual cable net structures.在典型索网结构的设计中，寻形是至关重要的。在原基本力密度法的基础上，利用关系矩阵的概念，提出了一种改进的力密度法。改进后的方法实现了索网结构构件与节点之间明确对应关系的建立。在关系矩阵的基础上，引入了find函数，推导了改进分支节点矩阵的计算公式。同时给出了相应的分析步骤和计算过程。通过对典型结构形式的分析，验证了改进后的方法。结果表明，对于鞍形正交索网结构，修正力密度法的计算结果与理论值吻合度较高，初步验证了该方法的有效性。对于单层辐条索网结构，修正力密度法计算结果与数值解的相对误差约为5%。两种方法的计算结果比较一致，相对误差随内环索力密度与径向索力密度之比的变化而变化。对于不带内环的单层圆形交叉索网结构，修正力密度法的结果与数值解非常接近。两者的最大相对误差为6.95%，精度高于非线性有限元法。研究结果验证了修正力密度法的准确性及其在实际索网结构寻形中的有效应用。来源：复合材料力学仿真Composites FEM