Mechanics of Materials最新文献_第9页

Development of generalized yield surface of fly ash microbubble composites using nonlinear multiscale analysis 粉煤灰微泡复合材料广义屈服面非线性多尺度分析研究

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-25 DOI: 10.1016/j.mechmat.2025.105532

Abdalla Elbana, Amar Khennane

This study presents a multiscale framework to model the nonlinear constitutive behavior of particulate composites containing hollow ceramic inclusions. The composite consists of an elasto-plastic epoxy matrix, plastic in compression and linear elastic in tension, reinforced with brittle, linearly elastic fly ash microbubbles

(40 {A l}_{2} O_{3} - 60 S i O_{2}) .

Representative volume elements (RVEs) with varying particle volume fractions (15–45 %) are used to capture the micromechanical response under multiaxial loading. A structured modeling strategy is employed, including the idealization of fly ash microbubbles as hollow spheres and calibration of cohesive zone models using experimental data and SEM fracture imaging. A three-dimensional yield surface is constructed from RVE simulations, incorporating pressure sensitivity and Lode angle dependence. A custom VUMAT subroutine was developed to implement the proposed yield function which incorporates compressive hardening, tensile softening via a fracture strain limit and a viscosity-based regularization scheme enhances stability in explicit dynamic simulations, especially under small strain increments with low hardening modulus or perfect plasticity. This unified micromechanics-driven approach enables simulation of progressive failure in syntactic foams and related composites.

本研究提出了一个多尺度框架来模拟含空心陶瓷夹杂颗粒复合材料的非线性本构行为。该复合材料由弹塑性环氧树脂基体组成，具有压缩塑性和拉伸线性弹性，并用脆性线弹性粉煤灰微泡（40Al2O3−60SiO2）增强。采用具有不同颗粒体积分数（15 - 45%）的代表性体积元（RVEs）来捕捉多轴加载下的微力学响应。采用结构化建模策略，包括将粉煤灰微气泡理想化为空心球体，并利用实验数据和SEM裂缝成像对黏结带模型进行校准。通过RVE模拟，结合压力敏感性和Lode角依赖性，构建了三维屈服面。开发了定制的VUMAT子程序来实现所提出的屈服函数，该函数结合了压缩硬化、断裂应变极限拉伸软化和基于粘度的正则化方案，增强了显式动态模拟的稳定性，特别是在低硬化模量或完美塑性的小应变增量下。这种统一的微观力学驱动方法可以模拟复合泡沫和相关复合材料的渐进破坏。

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引用次数: 0

Influence of experimental data set choice for constitutive parameters identification for machining simulations 实验数据集选择对加工仿真本构参数辨识的影响

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-18 DOI: 10.1016/j.mechmat.2025.105516

Adam Najem, Guillaume Altmeyer, Louis Esnault, Arnaud Duchosal

This work focuses on the characterization of the X100CrMoV5 steel alloy and the identification of its constitutive parameters for machining simulations using shear tests. Experimental tests were conducted on a thermo-mechanical Gleeble machine under dynamic conditions, at ambient and elevated temperatures. A numerical model was developed to simulate the shear test, enabling a comprehensive comparison with the experimental data. Both experimental and numerical data were de-noised using the Singular Value Decomposition (SVD) method, effectively removing experimental noise and numerical instabilities. The Levenberg–Marquardt identification algorithm based on gradient descent was then employed to minimize the error between numerical and experimental results, facilitating the simultaneous identification of all parameters of the material behavior model. This behavior model included an elastic phase, described by Hooke’s Law, followed by a thermo-visco-plastic phase, modeled using the Johnson–Cook law. The Johnson–Cook damage criterion was applied to determine the material’s rupture point, while the Hillerborg energy criterion was used to model energy dissipation during the damage process. Additionally, the Taylor–Quinney coefficient was incorporated to model thermo-mechanical dissipation. All parameters were identified through a global identification approach, wherein they were determined simultaneously to account for their inter-dependencies using all available experimental data. The experimental data sets where used either individually or collectively influencing the identification procedure. The results of the characterization and identification of the behavior of X100CrMoV5 are presented here, highlighting the material’s response under varying conditions and the role of the identification approach used.

本文重点研究了X100CrMoV5钢合金的特性，并通过剪切试验确定了其加工模拟的本构参数。在热机械Gleeble机器上进行了动态、常温和高温条件下的实验测试。建立了模拟剪切试验的数值模型，与试验数据进行了全面对比。采用奇异值分解（SVD）方法对实验数据和数值数据进行去噪，有效地消除了实验噪声和数值不稳定性。然后采用基于梯度下降的Levenberg-Marquardt识别算法，使数值结果与实验结果之间的误差最小，便于同时识别材料行为模型的所有参数。该行为模型包括一个由胡克定律描述的弹性阶段，以及一个由约翰逊-库克定律建模的热粘塑性阶段。采用Johnson-Cook损伤准则确定材料的破裂点，采用Hillerborg能量准则模拟材料损伤过程中的能量耗散。此外，泰勒-昆尼系数被纳入热机械耗散模型。所有参数都是通过全球识别方法确定的，其中它们是同时确定的，以利用所有可用的实验数据来解释它们的相互依赖性。单独或集体使用的实验数据集影响识别程序。本文介绍了表征和鉴定X100CrMoV5行为的结果，强调了材料在不同条件下的响应以及所使用的鉴定方法的作用。

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引用次数: 0

Enhancing nonlinear viscoelastic modeling of elastomers through neural networks: A deep rheological element 通过神经网络增强弹性体的非线性粘弹性建模：一种深度流变元件

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-16 DOI: 10.1016/j.mechmat.2025.105525

Federico Califano , Jacopo Ciambella

An established method for incorporating inelastic constitutive equations into finite element software is the use of rheological elements, assembled in series or in parallel, to describe the constitutive response at each material point. This approach can be extended to finite strains by exploiting the multiplicative decomposition of the deformation gradient. In this study, we propose an hybrid approach that integrates traditional elements with elements, with constitutive equations defined through deep neural networks (DNNs), into an assemblage of standard rheological elements. We formulate DNNs to guarantee thermodynamic consistency, enabling us to model the time-dependent, large strain response of elastomers and predict the Payne effect in filled rubber. This effect, characterized by deformation-enhanced shear thinning, poses unique modeling challenges. Additionally, we discuss data augmentation procedures to address the data-intensive nature of training neural networks, showcasing the effectiveness of utilizing ordinary dynamic mechanical analysis (DMA) tests for this purpose.

将非弹性本构方程纳入有限元软件的一种既定方法是使用流变单元，串联或并联组装，以描述每个材料点的本构响应。这种方法可以通过利用变形梯度的乘法分解扩展到有限应变。在这项研究中，我们提出了一种混合方法，将传统元素与元素结合起来，通过深度神经网络（dnn）定义本构方程，成为标准流变元素的组合。我们制定dnn以保证热力学一致性，使我们能够模拟弹性体的时间依赖性大应变响应，并预测填充橡胶中的Payne效应。这种以变形增强剪切变薄为特征的效应，对建模提出了独特的挑战。此外，我们讨论了数据增强程序，以解决训练神经网络的数据密集型性质，展示了为此目的利用普通动态力学分析（DMA）测试的有效性。

引用次数: 0

An augmented surface impedance theory for acoustically actuated magneto-electro-elastic nanospheres with terahertz nanoantenna applications 声致磁-电弹性纳米球的增广表面阻抗理论与太赫兹纳米天线应用

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-15 DOI: 10.1016/j.mechmat.2025.105515

Mohsen Farsiani , Hossein M. Shodja

A precise analytical treatment for predicting the behavior of nano-sized magneto-electro-elastic (MEE) antennas and resonators under incident acoustic waves requires careful consideration of multiphysics surface/interface effects, including magnetization, polarization, and elasticity. To date, no analytical solutions have incorporated all three phenomena simultaneously. By addressing these surface effects, this work presents a rigorous mathematical analysis of a nano-sized spherically isotropic embedded MEE spherical shell subjected to incident acoustic waves. The set of coupled spectral constitutive relations relevant to the bulk of the MEE spherical shell is distinguished from those pertinent to its free inner surface and matrix-shell interface. The surrounding matrix may consist of an isotropic dielectric or metallic material. Conventional electrodynamics theories are insufficient to address this problem, as they do not adequately account for MEE effects at the surface or interface. To overcome this limitation, the study employs the equivalent impedance matrix (EIM) method combined with surface/interface elasticity to model the surface/interface MEE behaviors rigorously. For metallic matrices, a plasmonics-based mathematical framework is utilized, with the optical properties described by the plasma model to accurately capture metallic behavior. The spectral EIM method, combined with vector and tensor spherical harmonics forming a Schauder basis for square-integrable vector fields and second-rank symmetric tensor fields on the unit sphere, is shown to be a pivotal tool for solving the fully coupled elastodynamics and Maxwell’s equations. This approach is particularly effective in capturing significant MEE surface/interface effects. This methodology enables a detailed exploration of surface/interface characteristic lengths, facilitating the examination of size-dependent effects on electromagnetic radiated power and fundamental resonance frequency. The findings provide valuable insights into the behavior of acoustically actuated nanospherical antennas, nanosensors, and nanoresonators based on MEE nanospheres. Moreover, these results have significant implications for the design and optimization of nanoscale devices in advanced technological applications.

预测纳米磁电弹性（MEE）天线和谐振器在入射声波下的行为需要仔细考虑多物理场表面/界面效应，包括磁化、极化和弹性。迄今为止，还没有一种解析解能同时包含这三种现象。通过解决这些表面效应，本工作对入射声波下的纳米球形各向同性嵌入MEE球壳进行了严格的数学分析。将有关MEE球壳体积的耦合谱本构关系集与有关其自由内表面和基壳界面的耦合谱本构关系集进行了区分。所述周围基质可由各向同性电介质或金属材料组成。传统的电动力学理论不足以解决这个问题，因为它们不能充分解释表面或界面上的MEE效应。为了克服这一局限性，本研究采用等效阻抗矩阵（EIM）方法结合表面/界面弹性来严格模拟表面/界面MEE行为。对于金属基体，利用等离子体模型描述的光学特性，利用基于等离子体的数学框架精确捕捉金属的行为。谱EIM方法结合矢量和张量球面谐波构成单位球上平方可积矢量场和二阶对称张量场的Schauder基，是求解完全耦合弹性动力学和麦克斯韦方程组的关键工具。这种方法在捕获重要的MEE表面/界面效应方面特别有效。该方法可以详细探索表面/界面特征长度，便于检查尺寸对电磁辐射功率和基共振频率的影响。这些发现为基于MEE纳米球的声驱动纳米球形天线、纳米传感器和纳米谐振器的行为提供了有价值的见解。此外，这些结果对纳米级器件的设计和优化具有重要意义。

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引用次数: 0

Electrically induced local creep in dielectric polymers: Experiments and modeling 电介质聚合物中的电致局部蠕变：实验和建模

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-15 DOI: 10.1016/j.mechmat.2025.105529

Zhigang Liu , Guian Man , Xuhui Fan , Boyuan Huang , Jiangyu Li

Dielectric polymers such as biaxially oriented polypropylene (BOPP) are widely used in capacitors for electric energy storage and pulse power. Under working conditions, they are subjected to high voltage as well as cyclic charging and discharging, resulting in significant Maxwell strain that evolves due to viscoelasticity. Such creep behavior has important implications to the reliability, aging, and breakdown failure of dielectric polymers, and we seek to understand it with the goal to predict the long term strain evolution using short term experimental data. We established a digital image correlation based experimental setup to monitor field induced deformation in-situ, observing significant strain concentration as well as creep. We carried out systematical analysis using Burgers model and find that it is incapable of predicting long term local creep of BOPP at strain concentration, despite its success in capturing mechanical creep as well as the evolution of average strain under an electric field. We thus developed a modified Burgers model that accounts for the evolution of concentrated electric field and accurately predicted long term local creep under either constant or cyclic voltage. In particular, we successfully predicted the evolution of concentrated local strain up to 10⁶ s using the experimental data in the first 10³ s, demonstrating the power of our modified Burgers model. We expect that the modified Burgers model will play an important role in analyzing aging and failure behaviors of dielectric polymers and capacitive devices.

双轴取向聚丙烯（BOPP）等介电聚合物广泛应用于储能电容器和脉冲电源中。在工作条件下，它们承受高电压以及循环充放电，导致由于粘弹性而演变的显著麦克斯韦应变。这种蠕变行为对介电聚合物的可靠性、老化和击穿失效具有重要意义，我们试图理解它，目的是利用短期实验数据预测长期应变演变。我们建立了一个基于数字图像相关的实验装置来监测现场引起的变形，观察到显著的应变集中和蠕变。我们使用Burgers模型进行了系统分析，发现尽管它成功地捕获了机械蠕变以及电场下平均应变的演变，但它无法预测应变浓度下BOPP的长期局部蠕变。因此，我们开发了一个改进的Burgers模型，该模型考虑了集中电场的演变，并准确地预测了恒定或循环电压下的长期局部蠕变。特别是，利用前103 s的实验数据，我们成功地预测了106 s内集中局部应变的演化，证明了改进的Burgers模型的有效性。我们期望改进的Burgers模型将在分析介电聚合物和电容器件的老化和失效行为方面发挥重要作用。

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引用次数: 0

A physics-based crystal plasticity model of nickel-based single crystal superalloy for different loading conditions under a wide temperature range 基于物理的镍基单晶高温合金在宽温度范围内不同加载条件下的晶体塑性模型

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-14 DOI: 10.1016/j.mechmat.2025.105528

Jiaxuan Wang , Rou Du , Liu Chen , Hansong Ma , Xiaoming Liu , Yueguang Wei

Nickel-based single crystal (NBSC) superalloys are extensively used in the fabrication of turbine blades for aero engines, where their deformation behaviours play a critical role in ensuring flight safety. The deformation behaviours are governed by complex micro-scale mechanisms, such as matrix slip, precipitate shearing, interface dislocation pile-up, dislocation climb, coarsening, and rafting. However, many existing models either inadequately account for the underlying deformation mechanisms or rely heavily on temperature-sensitive material parameters, both of which undermine their predictive accuracy and generalizability under diverse loading and thermal conditions. To address these limitations, this study develops a robust and versatile crystal plasticity model that incorporates the above mechanisms. The model decouples temperature effects from constitutive parameters to mitigate parameter sensitivity to temperature variations. Additionally, a parameter decoupling strategy is employed to reduce the number of adjustable parameters and facilitate their identification. The model is validated against experimental data for the DD6 superalloy under uniaxial tension, creep, and low-cycle fatigue tests conducted across a wide temperature range (20–980 °C). The predicted mechanical responses demonstrate good agreement with the experimental results. Finally, the model is applied to simulate the mechanical behaviour of a specimen with inclined cooling holes. The model gives a nearly linear response of creep displacement, which matches well with the experiments.

镍基单晶高温合金广泛应用于航空发动机涡轮叶片的制造，其变形行为对保证飞行安全起着至关重要的作用。变形行为受基体滑移、析出相剪切、界面位错堆积、位错爬升、粗化和漂流等复杂微观机制控制。然而，许多现有的模型要么不能充分考虑潜在的变形机制，要么严重依赖于温度敏感的材料参数，这两者都破坏了它们在不同载荷和热条件下的预测准确性和通用性。为了解决这些限制，本研究开发了一个包含上述机制的健壮且通用的晶体塑性模型。该模型将温度效应与本构参数解耦，降低了本构参数对温度变化的敏感性。此外，采用参数解耦策略减少了可调参数的数量，便于辨识。该模型通过DD6高温合金在单轴拉伸、蠕变和宽温度范围（20-980°C）下的低周疲劳试验数据进行了验证。预测的力学响应与实验结果吻合较好。最后，将该模型应用于具有倾斜冷却孔的试样的力学行为模拟。该模型给出了蠕变位移的近似线性响应，与实验结果吻合较好。

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引用次数: 0

Micromechanical modeling and property prediction of bamboo with gradient random vascular bundles 梯度随机维管束竹的微观力学模型及性能预测

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-14 DOI: 10.1016/j.mechmat.2025.105527

Yubo Hou , Adel Noori , Kairan Zhang , Yuhan Zheng , Hao Wang , Yubin Lu

Bamboo has gained significant attention in sustainable buildings for its rapid growth rate and impressive mechanical properties comparable to wood. The volume fraction and gradient arrangement of vascular bundles directly influence the mechanical properties of bamboo. This paper proposes a novel gradient random distribution method, which can accurately restore the gradient distribution of bamboo vascular bundles along the radial direction of the culm wall. The aim is to uncover the relationship between the gradient distribution pattern of vascular bundles and the mechanical properties. The gradient random distribution method helps to transform the uniform random Representative Volume Element model into a gradient random distribution numerical model using the concept of coordinate transformation. The comparative analysis was conducted between the uniform random distribution method and the gradient random distribution method to predict the effective elastic properties of bamboo vascular bundles. The results indicated that elastic modulus and shear modulus of bamboo exhibit an exponential increase from the inner to the outer layers along the radial direction of the culm wall. Larger fiber spacing can slightly decrease the corresponding shear modulus. Moreover, the gradient random distribution method is capable of predicting accurately the elastic stiffness properties of full-sized bamboo culm compared to the uniform random distribution method.

竹子因其快速的生长速度和可与木材媲美的令人印象深刻的机械性能而在可持续建筑中获得了极大的关注。维管束的体积分数和梯度排列直接影响竹子的力学性能。本文提出了一种新的梯度随机分布方法，可以准确地恢复竹维管束沿茎壁径向的梯度分布。目的是揭示维管束的梯度分布模式与力学性能之间的关系。梯度随机分布方法利用坐标变换的概念，将均匀随机的代表性体元模型转化为梯度随机分布的数值模型。对均匀随机分布法和梯度随机分布法预测竹维管束有效弹性特性进行了对比分析。结果表明：竹材的弹性模量和剪切模量沿茎壁径向由内层向外层呈指数增长；较大的纤维间距可使相应的剪切模量略有降低。与均匀随机分布法相比，梯度随机分布法能较准确地预测全尺寸竹竿的弹性刚度特性。

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引用次数: 0

Delineating strain-rate hardening and inertial effects on dynamic hardness of materials 描述了应变率硬化和惯性效应对材料动态硬度的影响

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-11 DOI: 10.1016/j.mechmat.2025.105523

Zahra Ghasemi , Tiago dos Santos , Debjoy D. Mallick , José A. Rodríguez-Martínez , Ankit Srivastava

We examine the interplay between strain-rate hardening and structural inertia in dynamic indentation, with the objective of identifying when dynamic hardness reflects intrinsic material response versus when it is influenced by inertia. Finite element simulations and theoretical calculations – based on a dynamic cavity expansion model – are performed for materials described by a strain- and strain-rate-dependent constitutive model with thermal softening. The analysis spans a broad range of indentation velocities, depths, material densities, and strain-rate sensitivity exponents. Our results show that at relatively low to moderate indentation velocities, dynamic hardness can be interpreted as an intrinsic material property. However, at sufficiently high velocities, the indentation response is significantly influenced by inertia-induced resistance, manifested by a rapid increase in hydrostatic stress and, consequently, in dynamic hardness. The extent of this resistance scales with indentation strain rate, indentation depth, and material density. We introduce a normalization approach that, for a given material, accounts for inertia by scaling dynamic hardness and indentation strain rate with reference functions that depend on indentation velocity. This procedure enables the identification of the loading rate at which inertia begins to dominate the indentation response and allows data across a wide range of indentation strain rates and depths to be interpreted in terms of the material’s intrinsic strain-rate-dependent constitutive behavior. The excellent agreement between finite element simulations and theoretical predictions underscores the robustness of the proposed approach and establishes a foundation for extracting strain-rate-sensitive material properties from dynamic indentation experiments.

我们研究了动态压痕中应变率硬化和结构惯性之间的相互作用，目的是确定动态硬度是反映材料的固有响应还是受惯性影响。基于动态空腔膨胀模型的有限元模拟和理论计算，对由应变和应变率相关的热软化本构模型描述的材料进行了模拟和理论计算。该分析涵盖了广泛的压痕速度、深度、材料密度和应变率灵敏度指数。我们的结果表明，在相对低到中等压痕速度下，动态硬度可以解释为材料的固有特性。然而，在足够高的速度下，压痕响应明显受到惯性诱导阻力的影响，表现为静水应力的迅速增加，从而导致动态硬度的增加。这种阻力的程度与压痕应变率、压痕深度和材料密度有关。我们引入了一种归一化方法，对于给定的材料，通过缩放动态硬度和压痕应变率与依赖于压痕速度的参考函数来解释惯性。这一过程可以确定惯性开始主导压痕响应的加载速率，并允许在大范围内的压痕应变率和深度的数据被解释为材料的固有应变率相关的本构行为。有限元模拟与理论预测之间的良好一致性强调了所提出方法的鲁棒性，并为从动态压痕实验中提取应变率敏感材料性能奠定了基础。

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引用次数: 0

Effect of microdamage on the failure of open-hole UD GFRP laminates: A combined experimental and numerical study 微损伤对开孔UD玻璃钢复合材料破坏的影响：实验与数值相结合的研究

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-10 DOI: 10.1016/j.mechmat.2025.105524

Özgün Şener , Altan Kayran

The effect of microdamaging on the failure of unidirectional Interglas 92145/CR80 GFRP laminates is studied through experiments and a numerical approach combining Enhanced Schapery Theory (EST) and Crack Band Theory (CBT). Open-hole tension tests with various layer configurations, along with flat tensile tests were conducted to examine failure modes and their progression. The initiation and development of failure mechanisms were tracked experimentally using DIC imaging. In the numerical model, the matrix microdamage is represented through dissipated energy-dependent functions derived from standardized mechanical tests. Without discretely modeling splitting cracks, the numerical approach captured narrow zones of fiber and matrix failure coincident with experimentally observed crack paths. Axial, transverse, and shear strain fields from the physical and virtual tests were compared at the critical stages of the testing regimen. Comparison of the strain fields, as well as stress-strain curves from the numerical and experimental studies showed good agreement, suggesting that incorporation of microdamage modeling—rarely implemented in progressive failure analyses—offers potential for improving failure predictions in GFRP laminates.

结合增强Schapery理论（EST）和裂纹带理论（CBT），通过实验和数值方法研究了微损伤对单向interglass 92145/CR80玻璃钢层合板失效的影响。进行了各种层构型的裸眼拉伸试验，以及平面拉伸试验，以检查破坏模式及其进展。实验中使用DIC成像技术跟踪了失效机制的发生和发展。在数值模型中，通过标准化力学试验的耗散能量依赖函数来表示基体微损伤。数值方法没有对劈裂裂纹进行离散建模，而是捕获了与实验观察到的裂纹路径一致的纤维和基体的狭窄破坏区域。在试验方案的关键阶段，比较了物理和虚拟试验的轴向、横向和剪切应变场。应变场的比较，以及数值和实验研究的应力-应变曲线显示出良好的一致性，表明微损伤模型的结合-很少在渐进破坏分析中实施-提供了改进GFRP层合板的破坏预测的潜力。

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引用次数: 0

Achieving geometric accuracy in FFT-based micromechanical models using conformal grid 利用保形网格实现基于fft的微力学模型的几何精度

IF 4.1 3区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Mechanics of Materials

Pub Date : 2025-10-01 DOI: 10.1016/j.mechmat.2025.105512

Miroslav Zecevic, Ricardo A. Lebensohn, Laurent Capolungo

Owing to its efficiency, simplicity and robustness, the FFT-based method has become the standard for computation of mechanical fields in a heterogeneous periodic unit cell. One of the main disadvantages of the FFT-based method is the inaccurate representation of the initial microstructure on a regular grid of voxels, which can be alleviated through the use of distorted initial grids. In this paper, a method for generation of distorted initial grids conforming to the microstructural features (e.g. straight/curved boundaries) is proposed. The method determines the positions of the grid nodes in the initial configuration by solving a system of springs connecting the nodes. Microstructures consisting of layers, Voronoi tessellation and circular/spherical inclusions are considered, and mechanical fields simulated using the FFT-based method. It is found that distorted initial grids, conforming to the microstructural features, lead to more accurate mechanical fields in comparison to the corresponding non-distorted initial grid solution. The effect of initial grid distortion on the convergence of the FFT-based method is analyzed and discussed.

基于fft的方法由于其高效、简单和鲁棒性，已成为计算非均匀周期单元胞中力学场的标准方法。基于fft的方法的主要缺点之一是初始微观结构在规则体素网格上的不准确表示，可以通过使用扭曲的初始网格来缓解这一问题。本文提出了一种生成符合微观结构特征（如直/弯边界）的畸变初始网格的方法。该方法通过求解连接节点的弹簧系统来确定网格节点在初始构型中的位置。考虑了由层、Voronoi镶嵌和圆形/球形夹杂组成的微观结构，并使用基于fft的方法模拟了力学场。结果表明，与非畸变初始网格解相比，畸变初始网格解得到的力学场更为精确，且符合微观结构特征。分析和讨论了初始网格畸变对基于fft的方法收敛性的影响。

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引用次数: 0