【新文速递】2023年11月28日固体力学SCI期刊最新文章

今日更新：International Journal of Solids and Structures 2 篇，Journal of the Mechanics and Physics of Solids 1 篇，Mechanics of Materials 1 篇，International Journal of Plasticity 1 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresFrictionless line-to-line contact: Comparison of mortar and unbiased formulation in combination with Lagrange-multiplier and penalty methodTomec Jan, Jelenić Gordandoi:10.1016/j.ijsolstr.2023.112586无摩擦线对线接触：结合拉格朗日乘法器和惩罚法的砂浆和无偏公式比较Recent developments in the beam-to-beam contact mechanics have prompted us to investigate further into the relations between different formulations and contact-force models. Specifically we address in this paper the recently developed mortar method for beams and develop its variant based on the penalty method. This allows an in-depth comparison between the two formulations. Furthermore, we design an unbiased approach and introduce a new discretisation technique developed specifically for this method. The unbiased line-to-line method is also combined both with the Lagrange-multiplier and the penalty method. All developed elements have been tested using the same examples to provide an objective comparison between formulations in terms of robustness and computational cost.梁对梁接触力学的最新发展促使我们进一步研究不同公式和接触力模型之间的关系。具体而言，我们在本文中讨论了最近开发的梁灰泥法，并根据惩罚法开发了其变体。这样，我们就可以对两种公式进行深入比较。此外，我们还设计了一种无偏方法，并引入了专门为该方法开发的新离散化技术。无偏线对线方法还与拉格朗日乘法器和惩罚法相结合。我们使用相同的示例对所有开发的元素进行了测试，以便在鲁棒性和计算成本方面对各种公式进行客观比较。Improved deep artificial neural network-powered prediction of extreme mechanical performances of fractal architectures with high hierarchical rankViet N.V., Ilyas S., Zaki W.doi:10.1016/j.ijsolstr.2023.112591由深度人工神经网络驱动的高分层等级分形结构极端力学性能的改进预测This work explores the mechanical performances, including anisotropy, wave propagation, and buckling resistance capability of the Menger sponge and Jerusalem fractal structures, with the high rank, using an improved deep artificial neural network (ANN) model inserted by a loop with multiple conditions. Where, the effective mechanical attributes, including Young’s modulus, shear modulus, and Poisson’s ratio of the Menger sponge structure with rank 4 are attained using high-performance computer cluster (HPCC) that are then used to train and also validate the ANN model. The accuracy of the deep ANN model trained by data of fractal structures with and without rank 4 is verified by the numerical model and experiment with the good agreement found or the maximum percent difference being 15.6% where the numerical and experimental data don’t belong to its training samples. Remarkably, the deep ANN model demonstrates an extremely low cost, but very fast compared with the numerical and experimental works. Namely, the improved deep ANN model implemented by a regular computer can accurately predict the mechanical attributes of Menger sponge fractal structures with full ranks in 3 minutes. While it takes a week for numerical work using HPCC or experiment method to produce the same mechanical properties of the Menger sponge with only rank 4, displaying at least thousands of times slower than the ANN model. The ANN results indicate that the onset of anisotropy of considered fractal structures is from rank 1, and the reversal of anisotropy will take place upon an increase in the rank while such reversal is not seen for the case of lattice structure. The anisotropy reversal could be one of main reasons why the fractal structure tends to have a high rank in nature. In addition, the buckling stress and phase wave velocity are observed to decrease with rising rank, with a nonlinear pattern.这项研究利用一个改进的深度人工神经网络（ANN）模型，通过一个具有多个条件的循环，探索了高阶门格尔海绵和耶路撒冷分形结构的力学性能，包括各向异性、波传播和抗屈曲能力。其中，利用高性能计算机集群（HPCC）获得了等级为 4 的门格尔海绵结构的有效力学属性，包括杨氏模量、剪切模量和泊松比，然后用于训练和验证 ANN 模型。通过数值模型和实验验证了由有无秩 4 的分形结构数据训练出的深度 ANN 模型的准确性，结果表明，在数值数据和实验数据不属于其训练样本的情况下，两者的一致性良好，最大百分比差异为 15.6%。值得注意的是，与数值和实验结果相比，深度 ANN 模型成本极低，但速度极快。也就是说，用普通计算机实现的改进型深度 ANN 模型可以在 3 分钟内准确预测门格尔海绵分形结构的全等级力学属性。而使用 HPCC 或实验方法进行数值计算需要一周时间才能得出只有 4 级的门格尔海绵的相同力学属性，比 ANN 模型至少慢数千倍。方差分析结果表明，所考虑的分形结构的各向异性是从阶 1 开始的，阶数增加时各向异性会发生逆转，而晶格结构则不会发生这种逆转。各向异性反转可能是分形结构倾向于具有高秩的主要原因之一。此外，还观察到屈曲应力和相位波速随着阶数的增加而减小，呈现非线性模式。Journal of the Mechanics and Physics of SolidsLessons learned from matching 3D DEM and experiments at macro, meso and fabric scales for triaxial compression tests on lentilsPan Jin-hong, Pinzón Gustavo, Wang Rui, Andò Edward, Viggiani Gioacchino, Zhang Jian-Mindoi:10.1016/j.jmps.2023.105494将三维 DEM 与小扁豆三轴压缩试验的宏观、中观和织物尺度试验相匹配，从中汲取经验教训A series of discrete element method (DEM) triaxial compression simulations on specimens of an anisometric granular material starting from distinct initial fabric anisotropy states are conducted and compared with physical experiments on lentils at different scales, assisted by operando x-ray tomography measurements. A quantitative reproduction of the group of experimental results is achieved by appropriate idealization and determination of particle shape, boundary conditions, contact parameters, and initial state. The reliability of DEM in quantitative representation of macro scale stress–strain response, meso scale strain localization, and micro scale fabric anisotropy evolution is thus comprehensively validated against measurements from physical experiments, which is a step forward from comparisons only at the macro or particle kinematics level. Several key factors that govern realistic DEM simulations are also identified. The friction coefficient between particles during specimen generation, particle shape, and specimen preparation method can significantly affect the initial state of DEM specimens. Differences in initial state at macro and micro scales and boundary conditions can strongly influence the stress–strain response. However, the evolution of fabric anisotropy appears to be insensitive to changes in initial state and boundary conditions.在 X 射线断层扫描测量的辅助下，对从不同的初始结构各向异性状态开始的异性颗粒材料试样进行了一系列离散元法（DEM）三轴压缩模拟，并与不同尺度的扁豆物理实验进行了比较。通过对颗粒形状、边界条件、接触参数和初始状态的适当理想化和确定，实现了一组实验结果的定量再现。因此，DEM 在定量表示宏观尺度应力应变响应、中观尺度应变定位和微观尺度织物各向异性演变方面的可靠性得到了物理实验测量结果的全面验证，这比仅在宏观或颗粒运动学层面进行比较向前迈进了一步。此外，还确定了影响真实 DEM 模拟的几个关键因素。试样生成过程中颗粒之间的摩擦系数、颗粒形状和试样制备方法都会对 DEM 试样的初始状态产生重大影响。宏观和微观尺度上初始状态的差异以及边界条件会对应力-应变响应产生重大影响。然而，织物各向异性的演变似乎对初始状态和边界条件的变化并不敏感。Mechanics of MaterialsEffect of temperature on adhesion behavior of layered piezoelectric structureLuo Qing-Hui, Zhou Yue-Ting, Li Fengjun, Wang Lihuadoi:10.1016/j.mechmat.2023.104870温度对层状压电结构粘附行为的影响The effect of temperature on adhesion is neglected in classical adhesive contact theories. However, an increasing number of experimental results indicate that temperature has a prominent effect on adhesion behaviors. In this study, the anisothermal adhesive contact behaviors between two transversely isotropic piezoelectric cylinders with different initial temperatures is investigated by virtue of the generalized JKR model, where the contact interface is assumed to be perfectly bonded. The considered problem is reduced to coupled singular integral equations, which is derived by using the Fourier integral transform. The closed-form solutions of anisothermal generalized stress fields are obtained by taking the series expansion of the integrand induced by temperature difference. The effect of temperature difference on adhesion behaviors of two different types of layered piezoelectric structures under the action of mechanical-electro loadings is revealed. It is found that the pull-off force and contact size at pull-off moment decrease with increasing the temperature difference. The adhesion weakening effect induced by temperature difference diminishes when the electric loading is exerted. The results derived from this paper shed lights on understanding the adhesive contact behaviors of piezoelectric materials in the presence of temperature difference.经典的粘合接触理论忽略了温度对粘合力的影响。然而，越来越多的实验结果表明，温度对粘附行为有显著影响。在本研究中，通过广义 JKR 模型研究了两个具有不同初始温度的横向各向同性压电圆柱体之间的等温粘附接触行为，其中假定接触界面是完全粘合的。所考虑的问题被简化为耦合奇异积分方程，并通过傅立叶积分变换得到。通过对温差引起的积分进行序列展开，得到了等温广义应力场的闭式解。揭示了温差对两种不同类型的层状压电结构在机械电子负载作用下的粘附行为的影响。研究发现，拉脱力和拉脱时刻的接触尺寸随温差的增大而减小。施加电加载时，温差引起的附着力减弱效应减弱。本文得出的结果有助于理解压电材料在温差作用下的粘附接触行为。International Journal of PlasticityA generalized, computationally versatile plasticity model framework - Part I: Theory and verification focusing on tension‒compression asymmetryHou Yong, Du Kai, Min Junying, Lee Hyung-Rim, Lou Yanshan, Park Namsu, Lee Myoung-Gyudoi:10.1016/j.ijplas.2023.103818通用的、可计算的塑性模型框架--第一部分：以拉伸-压缩不对称为重点的理论与验证Microstructural characteristics and complex loading conditions in the deformation of metallic materials lead to complexity in mechanical responses. In this study, we propose a generalized constitutive framework that reproduces the plastic anisotropy and asymmetry under various loading conditions. Particularly, the developed model can accurately capture distinctive flow stress, plastic flow and strain hardening between tensile and compressive dominant loadings under a wide range of stress states. The model is based on the stress triaxiality dependence of state variable (or weighting factor) newly incorporated in the existing plasticity theory to keep the computational efficiency and versatility. For example, the new generalized framework can be applied to widely employed Hill48, Yld2k-2d, and Poly6 as a class of associated flow rule-based yield functions, as well as Stoughton-Yoon2009 and Min2016 yield functions for the non-associated flow rule. Also, the model is adaptable when selecting the yield function under tension or compression, which efficiently controls the degree of accuracy in anisotropic modeling under tension and compression. The generalized plasticity framework is validated comprehensively by demonstrating the predictive capability for anisotropy in yield stress and plastic flow of metallic materials with different crystal structures. Moreover, the model can efficiently capture the continuous evolution of asymmetric yield surfaces as functions of strain, temperature, and strain rate. Finally, the identification procedure of the model is discussed by demonstrating the analytical determination of model parameters utilizing the experimental or generic material data obtained from various loading conditions such as tension, compression, plane strain loading and pure shear.金属材料变形过程中的微观结构特征和复杂的加载条件导致了机械响应的复杂性。在本研究中，我们提出了一种通用的构成框架，它能再现各种加载条件下的塑性各向异性和不对称。特别是，所开发的模型能在广泛的应力状态下准确捕捉拉伸和压缩主导载荷之间独特的流动应力、塑性流动和应变硬化。该模型基于现有塑性理论中新加入的状态变量（或权重因子）的应力三轴依赖性，以保持计算效率和通用性。例如，新的广义框架可应用于广泛采用的基于关联流动规则的 Hill48、Yld2k-2d 和 Poly6 屈服函数，以及非关联流动规则的 Stoughton-Yoon 2009 和 Min2016 屈服函数。此外，该模型在选择拉伸或压缩下的屈服函数时具有适应性，可有效控制拉伸和压缩下各向异性建模的精确度。通过展示不同晶体结构金属材料屈服应力和塑性流动各向异性的预测能力，全面验证了广义塑性框架。此外，该模型还能有效捕捉非对称屈服面作为应变、温度和应变率函数的连续演化。最后，通过演示利用从拉伸、压缩、平面应变加载和纯剪切等各种加载条件下获得的实验或通用材料数据分析确定模型参数的过程，讨论了模型的识别程序。Thin-Walled StructuresMagneto-thermo-elastic Coupled Free Vibration and Nonlinear Frequency Analytical Solutions of FGM Cylindrical ShellHu Yuda, Zhou Qi, Yang Taodoi:10.1016/j.tws.2023.111406FGM 圆柱壳的磁热弹耦合自由振动和非线性频率解析解The magneto-thermo-elastic coupled free vibration of functionally graded materials (FGM) cylindrical shell is investigated. Based on the physical neutral surface theory and Kirchhoff-Love theory, the expressions of internal force and internal torque are obtained by considering the constitutive relationship that includes thermal stress. According to the electromagnetic elasticity theory, the model of Lorentz forces of the shell in magnetic field are derived. The expressions of potential energy, kinetic energy and its variational operators are given by introducing geometric nonlinearity, respectively. Based on Hamilton principle, the magneto-thermal-elastic coupled vibration equation of FGM cylindrical shell in multi-physical field is established. The displacement functions under simply supported boundary conditions are solved, which are combined with Galerkin method for derivation of nonlinear ordinary differential equations. The second-order approximate analytical solution of natural frequency is obtained by applying the multi-scale method. The characteristic curves of natural frequency with different parameters are drawn through numerical examples. The results show that reducing the volume fraction index and increasing the initial amplitude can lead to the increase of the natural frequency under transient conditions. With the increase of temperature and magnetic induction intensity, the natural frequency decreases. In addition, the natural frequency is also influenced by the shell size and volume fraction index.研究了功能分级材料（FGM）圆柱形壳体的磁热弹性耦合自由振动。基于物理中性面理论和基尔霍夫-洛夫理论，通过考虑包含热应力的构成关系，得到了内力和内扭矩的表达式。根据电磁弹性理论，推导出了磁场中壳体的洛伦兹力模型。通过引入几何非线性，分别给出了势能、动能及其变分算子的表达式。基于汉密尔顿原理，建立了 FGM 圆柱壳在多物理场中的磁-热-弹性耦合振动方程。求解了简单支撑边界条件下的位移函数，并结合 Galerkin 方法推导出非线性常微分方程。应用多尺度法得到了固有频率的二阶近似解析解。通过数值实例绘制了不同参数下的固有频率特征曲线。结果表明，在瞬态条件下，减小体积分数指数和增大初始振幅可导致固有频率的增加。随着温度和磁感应强度的增加，固有频率降低。此外，固有频率还受到壳体尺寸和体积分数指数的影响。来源：复合材料力学仿真Composites FEM