【新文速递】2024年1月25日固体力学SCI期刊最新文章

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

International Journal of Solids and Structures

Higher-Order Shear Deformation Theory for Accurate Prediction of Vibration Behavior of Thick Piezoelectric Disks and Design of Efficient Surface Electrodes

Ming Ji, Jia-Jin Zhong, Yi-Chuang Wu

doi:10.1016/j.ijsolstr.2024.112669

厚压电片振动特性精确预测的高阶剪切变形理论及高效表面电极设计

A modified higher-order shear deformation plate theory (MHSDT) is proposed to predict the resonance frequencies and related mode shapes of piezoelectric disks of various thicknesses. The theory explicitly accounts for the effects of the electrical potential on the displacement of the disk. The equations of motion for the disk are derived using Hamilton's principle in conjunction with a variational approach. It is shown analytically that the distribution of the electrical field on the surface of the disk is quantitatively similar to the distribution of the sum of the total stresses within the disk. Thus, the deformation of the disk can be approximated directly from the stress distribution on the disk, thereby greatly simplifying the solution process. The validity of the proposed MHSDT is confirmed by comparing the solutions for the natural frequencies, displacement fields, and electric field distributions of the disk for various radius-to-thickness ratios and boundary conditions with those obtained using Reddy’s third-order plate theory and COMSOL finite element simulations, respectively. The results show that the solutions obtained from the MHSDT method are consistently closer to the exact solutions than those determined using Reddy’s third-order method. Finally, the linear relationship between the electric field and the flexural displacement of the disk is leveraged to design surface electrodes capable of exciting specific flexural mode shapes of the disk under a free boundary condition. The efficiency of the designed electrodes is experimentally demonstrated using an amplitude-fluctuation electronic speckle pattern interferometer (AF-ESPI).

提出了一种改进的高阶剪切变形板理论(MHSDT)来预测不同厚度压电片的共振频率和相关振型。这个理论清楚地说明了电势对圆盘位移的影响。圆盘的运动方程是用汉密尔顿原理结合变分法推导出来的。分析表明，圆盘表面电场的分布与圆盘内总应力之和的分布在数量上是相似的。这样，圆盘的变形可以直接由圆盘上的应力分布近似求得，从而大大简化了求解过程。通过将不同半径厚度比和边界条件下圆盘的固有频率、位移场和电场分布的解分别与Reddy三阶板理论和COMSOL有限元模拟的解进行比较，证实了所提MHSDT的有效性。结果表明，用MHSDT方法得到的解比用Reddy的三阶方法得到的解更接近精确解。最后，利用电场与磁盘弯曲位移之间的线性关系，设计了能够在自由边界条件下激发磁盘特定弯曲模态形状的表面电极。利用振幅波动电子散斑干涉仪(AF-ESPI)对所设计电极的效率进行了实验验证。

Meso-structural optimization design of multifarious and complex fabric rubber composite structure

Yifeng Dong, Yutong Fu, Daining Fang

doi:10.1016/j.ijsolstr.2024.112672

多种复杂织物橡胶复合材料结构的细观结构优化设计

Fabric clothes are widely used to toughen the fabric rubber composite structure due to their strong designability and flexibility. The diversity and complexity of the meso-structural forms of fabric clothes bring great challenges to the efficient design of meso-structures of fabric rubber composite structure. The current studies are difficult to design the fabric rubber composite structure with complex structural forms whatever at macroscale or mesoscale. In this paper, the multiscale optimization design method of fabric rubber composite structure is established. Initially, the anisotropic theoretical models of the textile fabric rubber composite and reticulated fabric rubber composite are proposed based on meso-structural forms of the textile fabric and reticulated fabric. Then, the multiscale optimization framework and optimization process of fabric rubber composite structure, as well as the calculation methods of constraints and optimization objectives are established. Finally, the optimal meso-structures of textile fabric and reticulated fabric obtained by three optimization algorithms are compared. The results show that the difference of optimal meso-structures obtained by the three optimization algorithms is mainly reflected in the reticulated fabric. It is expected that the multiscale optimization design method has important scientific guiding significance for the performance improvement of fabric rubber composite structure.

由于织物橡胶复合材料具有较强的可设计性和柔韧性，被广泛应用于织物服装的增韧。织物服装细观结构形式的多样性和复杂性给织物橡胶复合材料细观结构的高效设计带来了巨大的挑战。无论是宏观尺度还是中尺度，目前的研究都难以设计出结构形式复杂的织物橡胶复合材料结构。建立了织物橡胶复合材料结构的多尺度优化设计方法。首先，基于纺织织物和网状织物的细观结构形式，提出了纺织织物橡胶复合材料和网状织物橡胶复合材料的各向异性理论模型。然后，建立了织物橡胶复合材料结构的多尺度优化框架和优化流程，以及约束条件和优化目标的计算方法。最后，对三种优化算法得到的纺织织物和网状织物的最优细观结构进行了比较。结果表明，三种优化算法得到的最优细观结构的差异主要体现在网状结构上。期望该多尺度优化设计方法对织物橡胶复合材料结构的性能改进具有重要的科学指导意义。

Mechanics of Materials

Numerical simulations of ductile crack initiation and growth in a textured magnesium alloy

S. Arjun Sreedhar, R. Narasimhan

doi:10.1016/j.mechmat.2024.104929

织构镁合金塑性裂纹萌生与扩展的数值模拟

In this work, the mechanics of ductile fracture near a notch tip in a basal textured Mg alloy is investigated through crystal plasticity based finite element analysis. An array of circular voids ahead of the tip subjected to mode I, plane strain, small scale yielding conditions is modelled. The effect of plastic anisotropy is examined by considering two notch orientations and contrasting the results against an isotropic plastic solid. The notch and the line perpendicular to it are chosen parallel to the transverse and rolling directions (TD and RD) in the first orientation, and along normal direction (ND) and TD in the second orientation. The TD-RD and isotropic cases show void-by-void growth for low initial porosity, fv0, and simultaneous multiple void growth for high fv0. By contrast, the ND-TD orientation displays the former even at high fv0. This is attributed to slower porosity evolution with J for this case due to high macroscopic hardening in the voided cells caused by pyramidal <c+a> slip and tensile twinning. The predicted crack growth resistance curves are also strongly influenced by fv0 and notch orientation.

本研究通过基于晶体塑性的有限元分析，研究了基底纹理镁合金缺口尖端附近的韧性断裂力学。在模态 I、平面应变和小尺度屈服条件下，对尖端前方的圆形空隙阵列进行建模。通过考虑两个缺口方向，并将结果与各向同性的塑性实体进行对比，研究了塑性各向异性的影响。在第一种取向中，槽口和垂直于槽口的线平行于横向和滚动方向（TD 和 RD），在第二种取向中，槽口和垂直于槽口的线平行于法线方向（ND）和 TD。TD-RD 和各向同性情况在初始孔隙率 fv0 较低时表现为逐个空隙增长，而在 fv0 较高时则表现为同时多个空隙增长；相比之下，ND-TD 方向即使在 fv0 较高时也表现为前者。这归因于这种情况下孔隙率随 J 的变化较慢，原因是金字塔 <c+a> 滑动和拉伸孪生导致空隙细胞中的宏观硬化程度较高。预测的裂纹生长阻力曲线也受到 fv0 和缺口取向的强烈影响。

Thin-Walled Structures

A multiscale modeling method with updatable ABD shells for laminated flexible solar arrays

Longlong Chen, Wujun Chen

doi:10.1016/j.tws.2024.111625

具有可更新ABD壳的层压柔性太阳能电池阵列多尺度建模方法

The flexible solar array is an innovative deployable system to provide electrical power for space stations, satellites, and other spacecrafts. Due to the advantages of lightweight, large area, and high power, it has received considerable attention and applications. However, the intricate multilayer configuration, nonlinear material behavior, and low stiffness characteristic of the array have made it always challenging to accurately predict the morphology and frequencies. This paper presents a numerical nonlinear multiscale method called PWL FE2 for large-scale flexible solar arrays. The proposed method is implemented in Abaqus with Python scripts and Micromechanics plugin. Its fundamental procedure is as follows: at microscale, the nonlinear constitutive model is piecewise linearly interpolated, followed by ABD stiffness and mass homogenizations of each segment; at macroscale, material properties of general ABD shells are updated based on section forces. Benchmark tests on substrate tension show that the error between PWL FE2 and direct numerical simulation (DNS) is less than 5%. The refined shell model with PWL FE2 algorithm proves to be computationally efficient and convergence-friendly for morphology and frequency analysis of the array. For the single array undergoing strong nonlinearity, the computational efficiency of PWL FE2 is nine times that of DNS. The out-of-plane displacement reaches up to 210 mm, and the differences in reaction forces and deformations between nonlinear and linear simulations exceed 20%. For the global array subjected to 84 N tensile loads, the array remains planar, and the first four modes are clustered around 0.2 Hz.

柔性太阳能阵列是一种创新的可展开系统，为空间站、卫星和其他航天器提供电力。由于其重量轻、面积大、功率大等优点，得到了相当大的重视和应用。然而，复杂的多层结构、非线性的材料特性和低刚度的阵列特性使得精确预测其形态和频率一直是一个挑战。本文提出了一种求解大型柔性太阳能电池阵的非线性多尺度数值方法PWL FE2。该方法在Abaqus中使用Python脚本和Micromechanics插件实现。其基本步骤是:在微观尺度上，对非线性本构模型进行分段线性插值，然后对各段进行ABD刚度和质量均匀化;在宏观尺度上，一般ABD壳体的材料性能是基于截面力进行更新的。基材张力的基准测试表明，PWL FE2与直接数值模拟(DNS)的误差小于5%。采用PWL FE2算法的改进壳层模型计算效率高，收敛性好，可用于阵列的形态和频率分析。对于单阵列强非线性，PWL FE2的计算效率是DNS的9倍。非线性模拟与线性模拟的反作用力和变形差异超过20%，面外位移达到210 mm。对于受84 N拉伸载荷的全局阵列，阵列保持平面，前四个模态聚集在0.2 Hz左右。

来源：复合材料力学仿真Composites FEM

【新文速递】2024年1月12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，Mechanics of Materials 1 篇，Thin-Walled Structures 1 篇International Journal of Solids and StructuresMultiscale simulation of polymer curing of composites combined mean-field homogenisation methods at large strainsPeter Lenz, Rolf Mahnkendoi:10.1016/j.ijsolstr.2023.112642复合材料聚合物固化的多尺度模拟，结合大应变下的均场均质化方法This work introduces a coupled thermo-chemo-mechanical framework for simulating the polymerisation process of composites, accounting for large strains. The framework encompasses the microscale, mesoscale and, macroscale. The microscale represents a step-growth polymerisation mechanism, which is modelled as a system of multiple growing spheres. These spheres are further decomposed into concentric layers of solid, resin, and curing agent material. At the mesoscale, the composite is divided into inclusions and the polymer matrix. The macroscale is considered as a homogeneous material. In order to describe the behaviour of the heterogeneous scales, mean-field homogenisation methods are employed. These methods have been developed before for linear elastic materials. However, considering finite deformations, a special treatment is necessary to accurately account for the effects of such deformations. Effective properties at all scales are obtained using the Mori–Tanaka, Voigt, Reuss, and Voigt–Reuss–Hill average mean-field homogenisation method. The results demonstrate how the different homogenisation methods influence the curing process and, consequently, the macroscopic response of the composite material.这项研究引入了一个热-化学-机械耦合框架，用于模拟复合材料的聚合过程，并考虑到大应变。该框架包括微观尺度、中观尺度和宏观尺度。微观尺度代表一种阶跃生长聚合机制，它被模拟为一个由多个生长球组成的系统。这些球体进一步分解成固体、树脂和固化剂材料的同心层。在中尺度上，复合材料分为夹杂物和聚合物基体。宏观尺度被视为均质材料。为了描述异质尺度的行为，采用了均场均质化方法。这些方法以前是针对线性弹性材料开发的。然而，考虑到有限变形，有必要采用特殊的处理方法来准确地解释这种变形的影响。使用 Mori-Tanaka、Voigt、Reuss 和 Voigt-Reuss-Hill 平均均场均质法获得了所有尺度上的有效特性。结果表明了不同的均质化方法如何影响固化过程，进而影响复合材料的宏观响应。Journal of the Mechanics and Physics of SolidsEnhancing toughness through geometric control of the process zoneSage Fulco, Michal K. Budzik, Kevin T. Turnerdoi:10.1016/j.jmps.2024.105548通过对加工区的几何控制提高韧性Material architecture provides an opportunity to alter and control the fracture process zone shape and volume by redistributing the local stresses at a crack tip. Properly designed structures can enlarge the plastic zone and enhance the effective toughness. Here, we use a pillar array as a model structure to demonstrate how variations in geometry at a crack tip control the size and shape of the plastic zone and can be used to engineer the effective toughness. Elastic–plastic finite element simulations are used to show how the pillar width, spacing, and height can be varied to tailor the size and shape of the plastic zone. A set of analytical mechanics models that accurately estimate the shape, volume, and resulting toughness as a function of the base material properties and geometry are also presented. A case study extends the analysis to sets of non-regular pillar arrays to illustrate how architecture can be used to alter toughness along the crack path.材料结构通过重新分配裂纹尖端的局部应力，为改变和控制断裂过程区的形状和体积提供了机会。设计合理的结构可以扩大塑性区并提高有效韧性。在此，我们以支柱阵列为模型结构，展示了裂纹尖端几何形状的变化如何控制塑性区的大小和形状，并可用于设计有效韧性。我们使用弹塑性有限元模拟来展示如何通过改变支柱的宽度、间距和高度来调整塑性区的大小和形状。此外，还介绍了一套分析力学模型，该模型可准确估计形状、体积和由此产生的韧性与基础材料特性和几何形状的函数关系。案例研究将分析扩展到非规则支柱阵列，以说明如何利用结构沿裂纹路径改变韧性。Mechanics of MaterialsMean field homogenization schemes using averages of stress, strain and strain energy density and applicationsTao Fu, Chuanying Li, Hao Hu, Xianghe Pengdoi:10.1016/j.mechmat.2024.104911使用应力、应变和应变能密度平均值的平均场均质化方案及其应用The average of stress (AS) and average of strain (AN) were often used in the development of conventional mean-field homogenization (MFH) schemes, but their correlation with the average of strain energy density (AE) has rarely been discussed. In this work, we examined the correlations of AE with AS and AN, and found that AE can be reduced to the product of AS or AN under uniform boundary stress or linear surface displacement associated with a uniform strain field. By introducing a reference matrix and using any two among AE, AS and AN, three MFH schemes were developed: NS (using AN and AS); NE (using AN and AE); and SE (using AS and AE). Following the concept of the Mori-Tanaka's (MT) method, three MFH schemes obtained above were reduced to MT-NS, MT-NE and MT-SE, respectively. Effective elastic properties of composites consisting of isotropic elastic matrices and spherical isotropic elastic inclusions were predicted using these schemes and compared with experimental results. The comparison revealed that MT-SE and MT-NS can reasonably replicate the experimental results in the case of moderate particle volume fractions and ratios between the Young's moduli of matrix and the reinforcement particles, demonstrating the validity of the MFH schemes. This work is significant because it not only clarifies the correlation of AE with AN and AS, but also provides more options for the development of MFH schemes, which can enrich the theory and methods for the analysis of the effective properties of composites.应力平均值（AS）和应变平均值（AN）经常被用于传统均场均质化（MFH）方案的开发，但它们与应变能量密度平均值（AE）的相关性却很少被讨论。在这项工作中，我们研究了 AE 与 AS 和 AN 的相关性，发现在均匀边界应力或与均匀应变场相关的线性表面位移条件下，AE 可以简化为 AS 或 AN 的乘积。通过引入参考矩阵并使用 AE、AS 和 AN 中的任意两个，开发出三种 MFH 方案：NS（使用 AN 和 AS）；NE（使用 AN 和 AE）；SE（使用 AS 和 AE）。按照森田中（Mori-Tanaka，MT）方法的概念，上述三种 MFH 方案分别简化为 MT-NS、MT-NE 和 MT-SE。利用这些方案预测了由各向同性弹性基体和球形各向同性弹性夹杂物组成的复合材料的有效弹性特性，并与实验结果进行了比较。比较结果表明，在颗粒体积分数和基体与增强颗粒的杨氏模量比适中的情况下，MT-SE 和 MT-NS 可以合理地复制实验结果，证明了 MFH 方案的有效性。这项工作意义重大，不仅阐明了 AE 与 AN 和 AS 的相关性，还为 MFH 方案的开发提供了更多选择，丰富了复合材料有效性能分析的理论和方法。Thin-Walled StructuresNumerical simulation of corroded circular hollow section steel columns: A corrosion evolution approachYun Zhao, Xuhong Zhou, Fei Xu, Tak-Ming Chandoi:10.1016/j.tws.2024.111594腐蚀圆形空心截面钢柱的数值模拟：腐蚀演变方法This study introduces a numerical simulation method for corroded circular hollow section steel columns, utilising a newly developed corrosion evolution model. This model was formulated by characterising the corrosion morphology and calibrating parameters throughout the entire corrosion process. An interpolation method was implemented to estimate the number of corrosion pits, based on experimentally measured corrosion ratios. Consequently, this allowed for the numerical prediction of the time-varying corrosion morphologies. Finite element (FE) models, incorporating this corrosion evolution model, were constructed. These corroded column models underwent validation through comparison with experimental findings. To further establish the effectiveness of the proposed FE models in predicting the structural behaviour of corroded members, FE models were also developed using the traditional uniform thickness reduction approach for comparative analysis. The results revealed that the proposed FE models for corroded structures offer a more accurate prediction of mechanical performance, particularly in instances of severe corrosion damage.本研究利用新开发的腐蚀演化模型，介绍了腐蚀圆形空心截面钢柱的数值模拟方法。该模型是通过描述整个腐蚀过程中的腐蚀形态和校准参数而建立的。根据实验测得的腐蚀比，采用内插法估算腐蚀坑的数量。因此，这样就可以对随时间变化的腐蚀形态进行数值预测。结合这种腐蚀演变模型，构建了有限元 (FE) 模型。这些腐蚀柱模型通过与实验结果的对比进行了验证。为了进一步确定所提出的有限元模型在预测腐蚀构件结构行为方面的有效性，还使用传统的均匀减厚方法开发了有限元模型，以进行对比分析。结果表明，针对腐蚀结构提出的有限元模型能够更准确地预测机械性能，尤其是在严重腐蚀损坏的情况下。来源：复合材料力学仿真Composites FEM