【新文速递】2023年9月25日固体力学SCI期刊最新文章

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

Journal of the Mechanics and Physics of Solids

Dynamic homogenization of heterogeneous piezoelectric media: A polarization approach using infinite-body Green’s function

Lee Jeong-Ho, Zhang Zhizhou, Gu Grace X.

doi:10.1016/j.jmps.2023.105442

异质压电介质的动态均质化：使用无限体格林函数的极化方法

Dynamic homogenization theories are powerful tools for describing and understanding the behavior of heterogeneous media such as composites and metamaterials. However, a major challenge in the homogenization theory is determining Green’s function of these media, which makes it difficult to predict their effective constitutive relations, particularly for the finite-size and/or non-periodic media in real-world applications. In this paper, we present a formulation for finding the elastodynamic effective constitutive relations for general heterogeneous media, including finite-size and non-periodic ones, via a polarization approach based on the Hashin–Shtrikman principle along with Green’s identities. Our proposed formulation relies on the infinite-body Green’s function of a homogeneous reference medium, making it free from the difficulty of determining Green’s function even for the homogenization of finite-size and/or non-periodic media. Additionally, we demonstrate the universal applicability of this formulation for both random and deterministic heterogeneous media. This work contributes to a better understanding of the homogenization theory and the design of next-generation metamaterials that require the accurate prediction of effective material characteristics for dynamic wave manipulation under desired operating environments.

动态均质化理论是描述和理解复合材料和超材料等异质介质行为的有力工具。然而，均质化理论的一个主要挑战是确定这些介质的格林函数，这使得预测它们的有效构成关系变得十分困难，特别是对于实际应用中的有限尺寸和/或非周期介质。在本文中，我们根据哈申-施特里克曼原理和格林常数，通过极化方法提出了一种计算方法，用于计算一般异质介质（包括有限尺寸和非周期性介质）的弹性动力有效构成关系。我们提出的公式依赖于均质参考介质的无穷体格林函数，因此即使是有限尺寸和/或非周期介质的均质化，也能摆脱确定格林函数的困难。此外，我们还证明了这一公式对随机和确定性异质介质的普遍适用性。这项工作有助于更好地理解均质化理论和设计下一代超材料，这些超材料需要准确预测有效材料特性，以便在所需的工作环境下进行动态波操纵。

Modeling heterogeneity and permeability evolution in a compaction band using a phase-field approach

Ip Sabrina C.Y., Borja Ronaldo I.

doi:10.1016/j.jmps.2023.105441

利用相场方法模拟压实带中的异质性和渗透性演变

Compaction bands are tabular zones of localized compressive deformation associated with porosity and permeability reduction. Depending on their orientation, compaction bands can act as barriers to fluid flow, and can be detrimental to fluid production in oil and gas reservoirs, as well as in CO2sequestration. The process of permeability reduction and the development of excess pore pressures during compaction band formation in a heterogeneous rock mass are not fully understood. Furthermore, few studies have modeled compaction band formation considering coupled hydromechanical processes. In this study, we propose a coupled hydromechanical, phase-field approach for capturing the formation and propagation of compaction bands in heterogeneous porous media. Breakage mechanics is adopted to characterize the free energy function in the intact and damaged material. The resulting phase-field variable provides a measure of the degree of grain crushing. Permeability reduction in the zone of compaction localization is modeled using the Kozeny-Carman equation accounting for microstructural evolution. Numerical simulations demonstrate the ability of the model to capture compaction band formation, porosity reduction, and permeability evolution under drained and undrained conditions. The results highlight the role of effective confining pressure, drainage conditions, and material parameters on the styles of compaction bands that form.

压实带是与孔隙度和渗透率降低有关的局部压缩变形的片状区域。根据其走向，压实带可成为流体流动的障碍，不利于油气藏以及二氧化碳储层的流体生产封存。人们对异质岩体中压实带形成过程中渗透率降低和孔隙压力过大的过程还不完全了解。此外，很少有研究在模拟压实带形成时考虑耦合的水文机械过程。在本研究中，我们提出了一种耦合水力学相场方法，用于捕捉异质多孔介质中压实带的形成和传播。采用破裂力学来描述完整和受损材料中的自由能函数。由此产生的相场变量提供了晶粒破碎程度的度量。压实局部区域的渗透性降低采用 Kozeny-Carman 方程建模，该方程考虑了微结构演变。数值模拟证明了该模型能够捕捉到排水和非排水条件下的压实带形成、孔隙度降低和渗透性演变。结果凸显了有效约束压力、排水条件和材料参数对压实带形成方式的作用。

International Journal of Plasticity

Modeling a sample size-dependency of martensitic phase transformation using a mesoscale framework

Vasoya Manish, Lagoudas Dimitris C.

doi:10.1016/j.ijplas.2023.103760

利用中尺度框架模拟马氏体相变的样品尺寸依赖性

Predicting a sample size-dependency of the constitutive response of any material system when it is being used in nano- and micro-scale devices, such as NEMS and MEMS, is very crucial for their design process. This also includes the shape memory alloys (SMAs), where predicting a sample size-dependency of the phase transformation process is the key aspect. Many experimental studies with micropillar compression tests showed an increase in critical stress to transformation and an increase in transformation hardening as the sample size decreases below a critical size. In this work, we have employed and extended a recently developed mesoscale framework to model such size effects in SMAs. A plane strain tensile SMA strip of finite width is analyzed within a small deformation framework. The martensitic transformation regions are modeled as Eshelby inclusions in an austenite phase matrix. Circular potential nucleation sites are considered with a square packing for their spatial locations and with nucleation stress assigned to each site from a Gaussian distribution. The combination of the Gaussian distribution of nucleation stress and the size of the nucleation site represents the underlying SMA material microstructure. Our numerical analysis, with varying values of the aspect ratio between the strip width and the nucleation site size, provides a critical value of the aspect ratio characterizing a transitioning length scale between a bulk vs. a sample size-dependent phase transformation behavior. At the transition, the critical stress to phase transformation and the transformation hardening increase drastically as the aspect ratio decreases below its critical value. The limitations of these predictions are discussed with existing literature on experimental observations, and some perspectives to improve the model are stated.

当任何材料系统用于纳米和微米尺度设备（如 NEMS 和 MEMS）时，预测其构成响应的样品尺寸依赖性对其设计过程至关重要。这也包括形状记忆合金（SMA），其中预测相变过程的样品尺寸依赖性是关键环节。许多微柱压缩试验研究表明，当样品尺寸减小到临界尺寸以下时，转变的临界应力会增加，转变硬化也会增加。在这项工作中，我们采用并扩展了最近开发的中尺度框架，以模拟 SMA 中的这种尺寸效应。在小变形框架内分析了有限宽度的平面应变拉伸 SMA 带。马氏体转变区域被模拟为奥氏体相基体中的埃舍尔比夹杂物。考虑了圆形潜在成核点，其空间位置采用正方形包装，每个成核点的成核应力采用高斯分布。成核应力的高斯分布与成核点大小的组合代表了 SMA 材料的基本微观结构。我们的数值分析采用了条带宽度与成核点尺寸之间不同的纵横比值，从而得出了纵横比的临界值，该值表征了体积与样品尺寸相关相变行为之间的过渡长度尺度。在过渡阶段，当纵横比减小到临界值以下时，相变的临界应力和转变硬化会急剧增加。我们结合现有的实验观察文献讨论了这些预测的局限性，并提出了一些改进模型的观点。

Thin-Walled Structures

Numerical and theoretical prediction of foreign object damage on AM355 simulated blade validated by ballistic impact tests

Zhang Hongbo, Hu Dayong, Ye Xubin, Chen Xin, He Yuhuai

doi:10.1016/j.tws.2023.111230

通过弹道冲击试验验证 AM355 模拟叶片上异物损伤的数值和理论预测

Foreign object damage (FOD) of aeroengine blade was a critical concern in aeroengine maintenance due to its potential impact on airworthiness. This study investigated FOD of simulated blades made of high-strength steel AM355 through a combination of experiments, finite element (FE) simulations, and theoretical analysis. Firstly, mechanical tests were conducted, including the quasi-static tensile tests at different triaxialities and temperatures, as well as Split-Hopkinson pressure bar (SHPB) tests. Experimental results showed that AM355 was sensitive to strain rate, with a 30.7% increase in yield strength observed at a strain rate of 3864 s−1. Then, a Johnson–Cook (J-C) model with failure criterion was developed and validated through FE analysis. The mechanical performance of AM355 was compared to that of TC4. Lastly, FOD tests accompanied by corresponding numerical simulations were conducted via the laboratory air gun device and the developed J-C model. The predicted notch morphologies and sizes agreed well with experimental observations, with the notch depth linearly increased with the increase of the projectile velocity. Finally, a FOD theory prediction model was developed through a spring-mass model based on Winkler's elastic-plastic foundation. The theoretical predictions were in good agreement with the numerical and experimental results, providing valuable insights for FOD assessment of real aeroengine blades.

航空发动机叶片的异物损伤（FOD）对适航性有潜在影响，是航空发动机维护中的一个重要问题。本研究通过实验、有限元（FE）模拟和理论分析相结合的方法，对高强度钢 AM355 制成的模拟叶片的 FOD 进行了研究。首先，进行了机械试验，包括不同三轴度和温度下的准静态拉伸试验，以及斯普利特-霍普金森压力棒（SHPB）试验。实验结果表明，AM355 对应变速率很敏感，在应变速率为 3864 s-1 时，屈服强度提高了 30.7%。随后，通过有限元分析建立并验证了具有失效准则的约翰逊-库克（J-C）模型。将 AM355 的机械性能与 TC4 进行了比较。最后，通过实验室气 枪装置和所开发的 J-C 模型进行了 FOD 测试和相应的数值模拟。预测的缺口形态和大小与实验观察结果非常吻合，缺口深度随射弹速度的增加而线性增加。最后，通过基于温克勒弹塑性基础的弹簧-质量模型，建立了 FOD 理论预测模型。理论预测结果与数值和实验结果十分吻合，为实际航空发动机叶片的 FOD 评估提供了宝贵的见解。

Effect of evolutionary anisotropic hardening on the prediction of deformation and forming load in incremental sheet forming simulation

Lee Hyung-Rim, Lee Myoung-Gyu, Park Namsu

doi:10.1016/j.tws.2023.111231

进化各向异性硬化对增量板材成形模拟中变形和成形载荷预测的影响

The incremental sheet forming (ISF) process typically accompanies large plastic strain without fracture exceeding uniform elongation or ultimate tensile strength (UTS) in the uniaxial tensile test. Therefore, ISF features improved formability compared to the conventional stamping process. Meanwhile, numerous studies have focused on modeling and simulation of formability in ISF where anisotropic yield function is one of the key constitutive laws for predicting sheet deformation. However, the conventional yield function is defined based on anisotropy of initial yielding, while the ISF modeling requires the deformation behavior at large strains beyond the UTS. In this study, an evolutionary anisotropic plasticity model is investigated based on Hill's 48 yield function combined with the non-associated flow rule; i.e., e-NAFR Hill's 48. The e-NAFR Hill's 48 model is implemented to the vectorized user-defined material subroutine in the commercial finite element software ABAQUS/Explicit. Then, the proposed FE model is applied to the forming of truncated cone, pyramid, and clover shaped single point incremental forming (SPIF) of an aluminum alloy 6014-T4 sheet. The simulated part profile, thickness variation, and forming force are compared with those of experiments. The evolutionary constitutive model shows an average accuracy of 99.15% in thickness prediction and 94.22% accuracy in forming force, demonstrating the importance of evolutionary sheet anisotropy in the SPIF process.

增量板材成形（ISF）工艺通常会产生较大的塑性应变，但不会在单轴拉伸试验中出现超过均匀伸长率或极限拉伸强度（UTS）的断裂。因此，与传统冲压工艺相比，ISF 具有更好的成形性。同时，许多研究都集中在 ISF 成型性的建模和模拟上，其中各向异性屈服函数是预测板材变形的关键构成法则之一。然而，传统的屈服函数是基于初始屈服的各向异性来定义的，而 ISF 建模则需要超出 UTS 的大应变变形行为。在本研究中，研究了基于希尔 48 屈服函数与非关联流动规则相结合的进化各向异性塑性模型，即 e-NAFR 希尔 48。e-NAFR Hill's 48 模型在商业有限元软件 ABAQUS/Explicit 的矢量化用户定义材料子程序中实现。然后，将所提出的有限元模型应用于铝合金 6014-T4 板材的截顶锥形、金字塔形和四叶草形单点增量成形（SPIF）。模拟的零件轮廓、厚度变化和成形力与实验结果进行了比较。进化构成模型在厚度预测方面的平均准确率为 99.15%，在成形力方面的平均准确率为 94.22%，证明了板材各向异性进化在 SPIF 过程中的重要性。