International Journal of Solids and Structures最新文献_第9页

Impact-induced breakage of a single particle: Effect of the intercell restitution coefficient 单个颗粒的冲击断裂：细胞间恢复系数的影响

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-03 DOI: 10.1016/j.ijsolstr.2025.113744

Duc Chung Vu

Despite the crucial role of breakable particles in numerous natural processes and industrial applications, accurately simulating particle breakage and its distinct variants remains a significant challenge for realistic discrete element method (DEM) simulations. In this work, we employ the bonded cell method (BCM), in which the particle is modeled as an aggregate of polyhedral cells whose common surfaces obey the Griffith fracture criterion, to simulate the fracture behavior of a single particle impacting a rigid plane. We focus on the influence of the restitution coefficient of cohesive bonds between cells on the particle fracture regimes and dissipated energy. We find that the crossover values of the damage potential

ω

, separating the three fracture regimes, follow a power-law relationship with the intercell restitution coefficient. Interestingly, at low values of

ω

corresponding to the first regime, where the particle undergoes the elastic rebound without crack formation, the effective restitution coefficient is independent of the intercell restitution coefficient. Our simulation data also reveal that the evolution of normalized energy dissipated by contact inelasticity and friction is well captured by a power-law function of

ω

. In the fragmented state, the power-law exponent is approximately 1 and remains independent of the intercell restitution coefficient, implying a linear dependence between the dissipated energy and the supplied kinetic energy. We show that the fraction of supplied energy lost to inelastic and frictional dissipation increases from about 50% to nearly 95% as the intercell restitution coefficient decreases. In contrast, in the damaged state, the power-law exponent is greater than 1 and decreases with decreasing intercell restitution coefficient. Finally, the dependence of several physical variables such as particle damage and fracture efficiency on the intercell restitution coefficient and impact velocity is also investigated.

尽管可破碎颗粒在许多自然过程和工业应用中起着至关重要的作用，但准确模拟颗粒破碎及其不同的变体仍然是现实离散元方法（DEM）模拟的重大挑战。在这项工作中，我们采用结合细胞方法（BCM），其中粒子被建模为多面体细胞的集合，其共同表面符合Griffith断裂准则，以模拟单个粒子撞击刚性平面的断裂行为。我们着重研究了细胞间内聚键的恢复系数对粒子断裂状态和耗散能量的影响。我们发现，分离三种断裂状态的损伤电位ω的交叉值与胞间恢复系数呈幂律关系。有趣的是，当ω值较低时，对应于第一种状态，即颗粒经历弹性反弹而没有形成裂纹，有效恢复系数与胞间恢复系数无关。我们的模拟数据还表明，接触非弹性和摩擦耗散的归一化能量的演变可以很好地由ω的幂律函数捕获。在破碎状态下，幂律指数约为1，并且与细胞间恢复系数无关，这意味着耗散的能量与提供的动能之间存在线性依赖关系。我们发现，随着胞间恢复系数的减小，非弹性和摩擦耗散所占的能量损失比例从约50%增加到近95%。而在损伤状态下，幂律指数大于1，且随胞间恢复系数的减小而减小。最后，研究了颗粒损伤和断裂效率等物理变量对胞间恢复系数和冲击速度的依赖关系。

{"title":"Impact-induced breakage of a single particle: Effect of the intercell restitution coefficient","authors":"Duc Chung Vu","doi":"10.1016/j.ijsolstr.2025.113744","DOIUrl":"10.1016/j.ijsolstr.2025.113744","url":null,"abstract":"<div><div>Despite the crucial role of breakable particles in numerous natural processes and industrial applications, accurately simulating particle breakage and its distinct variants remains a significant challenge for realistic discrete element method (DEM) simulations. In this work, we employ the bonded cell method (BCM), in which the particle is modeled as an aggregate of polyhedral cells whose common surfaces obey the Griffith fracture criterion, to simulate the fracture behavior of a single particle impacting a rigid plane. We focus on the influence of the restitution coefficient of cohesive bonds between cells on the particle fracture regimes and dissipated energy. We find that the crossover values of the damage potential <span><math><mi>ω</mi></math></span>, separating the three fracture regimes, follow a power-law relationship with the intercell restitution coefficient. Interestingly, at low values of <span><math><mi>ω</mi></math></span> corresponding to the first regime, where the particle undergoes the elastic rebound without crack formation, the effective restitution coefficient is independent of the intercell restitution coefficient. Our simulation data also reveal that the evolution of normalized energy dissipated by contact inelasticity and friction is well captured by a power-law function of <span><math><mi>ω</mi></math></span>. In the fragmented state, the power-law exponent is approximately 1 and remains independent of the intercell restitution coefficient, implying a linear dependence between the dissipated energy and the supplied kinetic energy. We show that the fraction of supplied energy lost to inelastic and frictional dissipation increases from about 50% to nearly 95% as the intercell restitution coefficient decreases. In contrast, in the damaged state, the power-law exponent is greater than 1 and decreases with decreasing intercell restitution coefficient. Finally, the dependence of several physical variables such as particle damage and fracture efficiency on the intercell restitution coefficient and impact velocity is also investigated.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"326 ","pages":"Article 113744"},"PeriodicalIF":3.8,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145428920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Design of curved-ligament honeycomb sandwich structures for optimal thermal buckling strength 弯曲韧带蜂窝夹层结构的最佳热屈曲强度设计

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-03 DOI: 10.1016/j.ijsolstr.2025.113733

Zheng Wu, Pai Liu, Di Guo, Zhan Kang, Yiqiang Wang

Honeycomb sandwich structures (HSSs) are extensively used in various engineering areas due to their exceptional mechanical properties. In applications such as the windward sides of hypersonic vehicles, thermal buckling is a primary failure mode that can lead to premature structure damage and compromise aerodynamic configurations. This paper proposes a novel design method aimed at optimizing the thermal buckling strength of HSSs by replacing the conventional straight ligaments in honeycomb cores with optimized curved ligaments. An optimization process is performed to identify the optimal free-form shapes of the curved ligaments for maximizing the critical buckling eigenvalue. The optimized curved-ligament HSSs demonstrate significant improvements in buckling temperatures compared to their straight-ligament counterparts, where the strength improvement can exceed 70%. The underlying mechanics indicates that the curved ligaments increase the local buckling resistance of the face sheets, and therefore the design method is particularly effective in the scenarios where local buckling of the face sheets is the dominant failure mode. In addition, the superior post-buckling performance of the curved-ligament HSSs is validated by considering temperature-dependent material properties. The curved-ligament HSSs are well-suited for applications involving high temperatures and substantial temperature gradients in aerospace contexts.

蜂窝夹层结构以其优异的力学性能被广泛应用于各种工程领域。在高超声速飞行器的迎风面等应用中，热屈曲是一种主要的失效模式，它可能导致结构过早损坏并损害气动配置。本文提出了一种新的设计方法，将蜂窝芯中传统的直韧带替换为优化的弯曲韧带，以优化蜂窝芯的热屈曲强度。为了使弯曲韧带的临界屈曲特征值最大化，对弯曲韧带的最佳自由形状进行了优化。优化后的弯曲韧带hss与直韧带hss相比，在屈曲温度方面有显著改善，强度提高可超过70%。基础力学表明，弯曲韧带增加了面板的局部屈曲阻力，因此该设计方法在面板局部屈曲为主要破坏模式的情况下特别有效。此外，通过考虑温度相关的材料特性，验证了弯曲韧带hss的优异后屈曲性能。弯曲韧带hss非常适合在航空航天环境中涉及高温和大量温度梯度的应用。

{"title":"Design of curved-ligament honeycomb sandwich structures for optimal thermal buckling strength","authors":"Zheng Wu, Pai Liu, Di Guo, Zhan Kang, Yiqiang Wang","doi":"10.1016/j.ijsolstr.2025.113733","DOIUrl":"10.1016/j.ijsolstr.2025.113733","url":null,"abstract":"<div><div>Honeycomb sandwich structures (HSSs) are extensively used in various engineering areas due to their exceptional mechanical properties. In applications such as the windward sides of hypersonic vehicles, thermal buckling is a primary failure mode that can lead to premature structure damage and compromise aerodynamic configurations. This paper proposes a novel design method aimed at optimizing the thermal buckling strength of HSSs by replacing the conventional straight ligaments in honeycomb cores with optimized curved ligaments. An optimization process is performed to identify the optimal free-form shapes of the curved ligaments for maximizing the critical buckling eigenvalue. The optimized curved-ligament HSSs demonstrate significant improvements in buckling temperatures compared to their straight-ligament counterparts, where the strength improvement can exceed 70%. The underlying mechanics indicates that the curved ligaments increase the local buckling resistance of the face sheets, and therefore the design method is particularly effective in the scenarios where local buckling of the face sheets is the dominant failure mode. In addition, the superior post-buckling performance of the curved-ligament HSSs is validated by considering temperature-dependent material properties. The curved-ligament HSSs are well-suited for applications involving high temperatures and substantial temperature gradients in aerospace contexts.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"326 ","pages":"Article 113733"},"PeriodicalIF":3.8,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145464475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Buckling of van der Waals materials 范德华材料的屈曲

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-02 DOI: 10.1016/j.ijsolstr.2025.113741

Huichao Liu, Yan Chen, Yilun Liu

Unlike common materials, van der Waals (vdW) materials are vulnerable to buckling under basal plane compression regardless of their slenderness. Understanding their post-buckling configurations is fundamental to preparing large-size high-quality samples, modulating physical properties, and revealing the strengthening and toughening mechanism in layered crystalline phases. Nevertheless, due to their unique features, such as layered crystalline lattice, decoupled intralayer and bending deformation mechanisms, and extreme anisotropy, vdW materials exhibit unique post-buckling behaviors that remain poorly understood. In this paper, we propose a general layered model, incorporating both the layered structure and interlayer tension–compression asymmetry, which can well capture the post-buckling evolvement behaviors for both bulk and finite-thickness vdW materials. The analytical expression of initial buckling strain is derived, only depending on two dimensionless parameters, reflecting the competition among intralayer compression, monolayer bending and interlayer shearing modes. For bulk vdW materials, the kink band configuration forms during the post-buckling deformation. Further analysis indicates that it is energetically driven by the release of intralayer and interlayer compression energies, stemming from the extreme anisotropy of layered crystalline structure, while the transformation from a sinusoidal configuration to a kink band configuration is induced by high interlayer pressure during post-buckling. In finite-thickness systems, three distinct post-buckling configurations are identified. i.e., internal kink, internal fold, global buckling, arising from the impaired lateral constraint as the slenderness increases. Phase diagrams for these three post-buckling configurations are presented. This work advances our understanding of the buckling and post-buckling evolvement behaviors in vdW materials, offering valuable insights for high-quality sample preparation and strengthening and toughening design of layered crystalline phases.

与普通材料不同，范德华（vdW）材料在基面压缩下容易发生屈曲，无论其长细比如何。了解它们的后屈曲结构是制备大尺寸高质量样品、调节物理性质和揭示层状晶体相强化和增韧机制的基础。然而，由于其独特的特性，如层状晶格、解耦的层内和弯曲变形机制以及极端的各向异性，vdW材料表现出独特的后屈曲行为，但人们对其了解甚少。在本文中，我们提出了一个综合层状结构和层间拉压不对称的通用层状模型，该模型可以很好地捕捉体和有限厚度vdW材料的屈曲后演化行为。导出了初始屈曲应变的解析表达式，仅依赖于二维参数，反映了层内压缩、单层弯曲和层间剪切模式之间的竞争。对于块状vdW材料，在屈曲后变形过程中会形成扭结带构型。进一步分析表明，由于层状晶体结构的极端各向异性，层内和层间压缩能的释放是其能量驱动的，而从正弦构型到扭结带构型的转变是由屈曲后的高层间压力引起的。在有限厚度系统中，确定了三种不同的屈曲后构型。即，内部扭结，内部褶皱，整体屈曲，产生的损害横向约束随着长细增加。给出了这三种后屈曲构型的相图。这项工作促进了我们对vdW材料屈曲和后屈曲演化行为的理解，为高质量样品的制备和层状晶相的强化和增韧设计提供了有价值的见解。

{"title":"Buckling of van der Waals materials","authors":"Huichao Liu, Yan Chen, Yilun Liu","doi":"10.1016/j.ijsolstr.2025.113741","DOIUrl":"10.1016/j.ijsolstr.2025.113741","url":null,"abstract":"<div><div>Unlike common materials, van der Waals (vdW) materials are vulnerable to buckling under basal plane compression regardless of their slenderness. Understanding their post-buckling configurations is fundamental to preparing large-size high-quality samples, modulating physical properties, and revealing the strengthening and toughening mechanism in layered crystalline phases. Nevertheless, due to their unique features, such as layered crystalline lattice, decoupled intralayer and bending deformation mechanisms, and extreme anisotropy, vdW materials exhibit unique post-buckling behaviors that remain poorly understood. In this paper, we propose a general layered model, incorporating both the layered structure and interlayer tension–compression asymmetry, which can well capture the post-buckling evolvement behaviors for both bulk and finite-thickness vdW materials. The analytical expression of initial buckling strain is derived, only depending on two dimensionless parameters, reflecting the competition among intralayer compression, monolayer bending and interlayer shearing modes. For bulk vdW materials, the kink band configuration forms during the post-buckling deformation. Further analysis indicates that it is energetically driven by the release of intralayer and interlayer compression energies, stemming from the extreme anisotropy of layered crystalline structure, while the transformation from a sinusoidal configuration to a kink band configuration is induced by high interlayer pressure during post-buckling. In finite-thickness systems, three distinct post-buckling configurations are identified. i.e., internal kink, internal fold, global buckling, arising from the impaired lateral constraint as the slenderness increases. Phase diagrams for these three post-buckling configurations are presented. This work advances our understanding of the buckling and post-buckling evolvement behaviors in vdW materials, offering valuable insights for high-quality sample preparation and strengthening and toughening design of layered crystalline phases.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"326 ","pages":"Article 113741"},"PeriodicalIF":3.8,"publicationDate":"2025-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145464479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Symmetries in stochastic homogenization and adjustments for the RVE method 随机均匀化中的对称性和RVE方法的调整

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-01 DOI: 10.1016/j.ijsolstr.2025.113728

Binh Huy Nguyen , Matti Schneider

We investigate the implications of a given symmetry of a random microstructure on the obtained effective tensor and its fluctuation in the context of thermal conductivity, and study strategies for enforcing these symmetries in postprocessing via orthogonal projectors. Within the framework of the representative volume element (RVE) method, we establish the invariance conditions for the effective tensor and its fluctuation under different symmetry groups of the microstructure. Interestingly, the symmetry of the considered cell type in the RVE method may break the ensemble symmetry and compromise the approximation of the effective properties. To rectify this issue, we introduce dedicated techniques which permit to enforce the expected symmetries in postprocessing and study the implications on the bounds for the effective properties as well as the total, the random and the systematic errors. We provide theoretical arguments that suitable projections lead to unbiased variance-reduction strategies which furthermore enforce the expected symmetries exactly. Through large-scale FFT-based homogenization simulations, we study the symmetry structure of the estimated effective conductivities and their fluctuations. Moreover, we demonstrate the power of the symmetry-projection techniques for fiber-reinforced composite microstructures of industrial scale.

我们研究了随机微观结构的给定对称性对获得的有效张量及其在导热性背景下的波动的影响，并研究了通过正交投影在后处理中增强这些对称性的策略。在代表性体积元（RVE）方法的框架内，建立了微观结构不同对称群下有效张量及其涨落的不变性条件。有趣的是，RVE方法中考虑的细胞类型的对称性可能会破坏系综对称性并损害有效性质的近似。为了纠正这一问题，我们引入了专门的技术，允许在后处理中强制执行预期的对称性，并研究了对有效属性以及总误差、随机误差和系统误差边界的影响。我们提供了理论论证，适当的预测导致无偏方差缩减策略，进一步加强预期的对称性。通过基于fft的大规模均匀化模拟，我们研究了估计有效电导率及其波动的对称性结构。此外，我们还展示了对称投影技术在工业规模纤维增强复合材料微结构中的作用。

{"title":"Symmetries in stochastic homogenization and adjustments for the RVE method","authors":"Binh Huy Nguyen , Matti Schneider","doi":"10.1016/j.ijsolstr.2025.113728","DOIUrl":"10.1016/j.ijsolstr.2025.113728","url":null,"abstract":"<div><div>We investigate the implications of a given symmetry of a random microstructure on the obtained effective tensor and its fluctuation in the context of thermal conductivity, and study strategies for enforcing these symmetries in postprocessing via orthogonal projectors. Within the framework of the representative volume element (RVE) method, we establish the invariance conditions for the effective tensor and its fluctuation under different symmetry groups of the microstructure. Interestingly, the symmetry of the considered cell type in the RVE method may break the ensemble symmetry and compromise the approximation of the effective properties. To rectify this issue, we introduce dedicated techniques which permit to enforce the expected symmetries in postprocessing and study the implications on the bounds for the effective properties as well as the total, the random and the systematic errors. We provide theoretical arguments that suitable projections lead to unbiased variance-reduction strategies which furthermore enforce the expected symmetries exactly. Through large-scale FFT-based homogenization simulations, we study the symmetry structure of the estimated effective conductivities and their fluctuations. Moreover, we demonstrate the power of the symmetry-projection techniques for fiber-reinforced composite microstructures of industrial scale.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"325 ","pages":"Article 113728"},"PeriodicalIF":3.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Recurrent neural network model predicting elasto-plasticity and matrix fracture in fiber-reinforced composites 纤维增强复合材料弹塑性和基体断裂的递归神经网络预测模型

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-01 DOI: 10.1016/j.ijsolstr.2025.113703

Arthur Girard, Dirk Mohr

An enhanced recurrent neural network model is proposed to predict the fracture initiation in addition to the elasto-plastic stress–strain response of solids. The stress-state dependency of the fracture initiation in an epoxy is characterized using shear, plane-strain tension and equi-biaxial tension experiments. A Drucker-Prager elasto-plasticity model with Hosford-Coulomb fracture is chosen to describe the experimentally-observed epoxy behavior. After detailing the extended minimal state cell (MSC) formulation, we first demonstrate that the RNN model is able to learn the deformation response of the matrix material based on synthetic data. Subsequently, an RVE model predicting the in-plane response of a carbon-fiber reinforced epoxy is built and used to generate training data for different types of random-walks in strain space. Based on the results of a comprehensive hyperparameter study, it is shown that a compact MSC model with five state variables and 6500 parameters is able to predict the homogenized stress–strain response of a fiber-reinforced composite along with the fracture initiation with the RVE. After demonstrating the model’s self-consistent behavior upon refining strain paths, it is also validated at the structural level by comparing its predictions for a three-point bending problem with those of a detailed heterogeneous model that discretizes all fibers in the beam.

除了固体的弹塑性应力-应变响应外，还提出了一种增强的递归神经网络模型来预测破裂起裂。通过剪切、平面应变拉伸和等双轴拉伸实验，表征了环氧树脂断裂起裂的应力状态依赖性。采用具有hoshford - coulomb断裂的Drucker-Prager弹塑性模型来描述实验观察到的环氧树脂行为。在详细介绍了扩展最小状态单元（MSC）公式之后，我们首先证明了RNN模型能够基于合成数据学习基体材料的变形响应。随后，建立了预测碳纤维增强环氧树脂面内响应的RVE模型，并用于生成应变空间中不同类型随机行走的训练数据。基于综合超参数研究的结果表明，一个包含5个状态变量和6500个参数的紧凑MSC模型能够预测纤维增强复合材料的均匀应力-应变响应以及随RVE的破裂起裂。在展示了模型在细化应变路径上的自一致行为之后，通过将其对三点弯曲问题的预测与将梁中的所有纤维离散化的详细非均质模型的预测进行比较，在结构层面上也对其进行了验证。

{"title":"Recurrent neural network model predicting elasto-plasticity and matrix fracture in fiber-reinforced composites","authors":"Arthur Girard, Dirk Mohr","doi":"10.1016/j.ijsolstr.2025.113703","DOIUrl":"10.1016/j.ijsolstr.2025.113703","url":null,"abstract":"<div><div>An enhanced recurrent neural network model is proposed to predict the fracture initiation in addition to the elasto-plastic stress–strain response of solids. The stress-state dependency of the fracture initiation in an epoxy is characterized using shear, plane-strain tension and equi-biaxial tension experiments. A Drucker-Prager elasto-plasticity model with Hosford-Coulomb fracture is chosen to describe the experimentally-observed epoxy behavior. After detailing the extended minimal state cell (MSC) formulation, we first demonstrate that the RNN model is able to learn the deformation response of the matrix material based on synthetic data. Subsequently, an RVE model predicting the in-plane response of a carbon-fiber reinforced epoxy is built and used to generate training data for different types of random-walks in strain space. Based on the results of a comprehensive hyperparameter study, it is shown that a compact MSC model with five state variables and 6500 parameters is able to predict the homogenized stress–strain response of a fiber-reinforced composite along with the fracture initiation with the RVE. After demonstrating the model’s self-consistent behavior upon refining strain paths, it is also validated at the structural level by comparing its predictions for a three-point bending problem with those of a detailed heterogeneous model that discretizes all fibers in the beam.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"326 ","pages":"Article 113703"},"PeriodicalIF":3.8,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145518003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fracture of rock-like materials: A gradient-damage theory 类岩石材料的断裂：梯度损伤理论

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-10-31 DOI: 10.1016/j.ijsolstr.2025.113739

Lallit Anand

We present a continuum theory for modeling the deformation, damage, and fracture of rock-like materials such as sandstone and over-consolidated clays. These quasi-brittle materials fail under low confining pressures through two primary modes: tensile brittle cracking and compressive ductile shear banding. Our framework integrates a finite-strain, rate-dependent Coulomb–Mohr type elasto-plasticity theory to model deformation, with a gradient-damage theory to capture the nucleation and evolution of damage leading to failure of these materials.

We implement the theory numerically in Abaqus/Explicit by exploiting an analogy between the governing equations of the coupled displacement-damage system and those of classical coupled displacement–temperature problems.

We illustrate the effectiveness of the model with several simulations, including: brittle fracture in sandstone under mixed-mode tensile loading, ductile shear banding in plane strain compression, and slope instability in over-consolidated clay under compressive loading.

我们提出了一个连续统理论来模拟岩石样材料（如砂岩和超固结粘土）的变形、损伤和断裂。这些准脆性材料在低围压下通过两种主要模式破坏：拉伸脆性开裂和压缩韧性剪切带。我们的框架集成了有限应变、速率相关的库仑-莫尔型弹塑性理论来模拟变形，以及梯度损伤理论来捕捉导致这些材料失效的损伤的成核和演变。利用位移-损伤耦合系统的控制方程与经典位移-温度耦合问题的控制方程之间的类比，在Abaqus/Explicit中对该理论进行了数值实现。我们通过几个模拟来说明该模型的有效性，包括：混合模式拉伸加载下砂岩的脆性断裂，平面应变压缩下的韧性剪切带，以及压缩加载下超固结粘土的边坡失稳。

引用次数: 0

A viscoelastic-plastic constitutive model for PEEK resin based on the physical model and artificial neural network 基于物理模型和人工神经网络的PEEK树脂粘弹塑性本构模型

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-10-30 DOI: 10.1016/j.ijsolstr.2025.113738

FeiYang Zhao, Jinzhao Huang, Shangyang Yu, Jikai Yu, Licheng Guo

This study systematically investigates the viscoelastic–plastic mechanical behavior of thermoplastic composite matrix PEEK-5600G under wide temperature range (23-180 °

C

) and multi strain rate (0.00229-0.19361/s) conditions. Tensile and stress relaxation experiments under large strain conditions and temperature-dependent viscoelastic parameters were conducted to obtain true stress responses. A novel physics-informed data-driven approach was proposed, where an Artificial Neural Network (ANN) architecture was developed for flow stress prediction. Through a comparative analysis methodology of multiple ANN configurations, the optimized model was acquired, demonstrating exceptional predictive capability characterized by a Pearson’s correlation coefficient of R=0.9998, Mean Squared Error

E_{MSE} = 1.12 E - 5

, and Average Absolute Relative Error

E_{AAR} = 3.42

%. Building upon experimental data and the optimized ANN framework, an incremental VK-ANN viscoelastic–plastic constitutive model was established by integrating Voigt–Kelvin viscoelastic theory with ANN-based flow rules. The corresponding VUMAT subroutine was implemented in the Abaqus/Explicit finite element code, with numerical simulations of tensile loading tests validating the model’s superior predictive accuracy.

本文系统地研究了热塑性复合材料基体PEEK-5600G在宽温度范围（23-180℃）和多应变速率（0.00229-0.19361/s）条件下的粘弹塑性力学行为。在大应变条件下和温度相关的粘弹性参数下进行了拉伸和应力松弛实验，获得了真实的应力响应。提出了一种新的物理信息数据驱动方法，其中开发了一种用于流动应力预测的人工神经网络（ANN）架构。通过对多个人工神经网络配置的对比分析，优化后的模型具有良好的预测能力，Pearson相关系数R=0.9998，均方误差EMSE=1.12E−5，平均绝对相对误差EAAR=3.42%。基于实验数据和优化后的人工神经网络框架，将voight - kelvin粘弹性理论与基于人工神经网络的流动规律相结合，建立了增量式VK-ANN粘弹塑性本构模型。在Abaqus/Explicit有限元代码中实现了相应的VUMAT子程序，并通过拉伸加载试验的数值模拟验证了该模型的优越预测精度。

{"title":"A viscoelastic-plastic constitutive model for PEEK resin based on the physical model and artificial neural network","authors":"FeiYang Zhao, Jinzhao Huang, Shangyang Yu, Jikai Yu, Licheng Guo","doi":"10.1016/j.ijsolstr.2025.113738","DOIUrl":"10.1016/j.ijsolstr.2025.113738","url":null,"abstract":"<div><div>This study systematically investigates the viscoelastic–plastic mechanical behavior of thermoplastic composite matrix PEEK-5600G under wide temperature range (23-180 °<span><math><mi>C</mi></math></span>) and multi strain rate (0.00229-0.19361/s) conditions. Tensile and stress relaxation experiments under large strain conditions and temperature-dependent viscoelastic parameters were conducted to obtain true stress responses. A novel physics-informed data-driven approach was proposed, where an Artificial Neural Network (ANN) architecture was developed for flow stress prediction. Through a comparative analysis methodology of multiple ANN configurations, the optimized model was acquired, demonstrating exceptional predictive capability characterized by a Pearson’s correlation coefficient of R=0.9998, Mean Squared Error <span><math><mrow><msub><mrow><mi>E</mi></mrow><mrow><mi>MSE</mi></mrow></msub><mo>=</mo><mn>1</mn><mo>.</mo><mn>12</mn><mi>E</mi><mo>−</mo><mn>5</mn></mrow></math></span>, and Average Absolute Relative Error <span><math><mrow><msub><mrow><mi>E</mi></mrow><mrow><mi>AAR</mi></mrow></msub><mo>=</mo><mn>3</mn><mo>.</mo><mn>42</mn></mrow></math></span>%. Building upon experimental data and the optimized ANN framework, an incremental VK-ANN viscoelastic–plastic constitutive model was established by integrating Voigt–Kelvin viscoelastic theory with ANN-based flow rules. The corresponding VUMAT subroutine was implemented in the Abaqus/Explicit finite element code, with numerical simulations of tensile loading tests validating the model’s superior predictive accuracy.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"326 ","pages":"Article 113738"},"PeriodicalIF":3.8,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145464476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Efficient uncertainty quantification for critical buckling loads and determination of knockdown factors in nonlinear structures 非线性结构中临界屈曲载荷的有效不确定性量化及击倒因子的确定

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-10-30 DOI: 10.1016/j.ijsolstr.2025.113734

David Y. Risk-Mora , Mauricio Aristizabal , Harry Millwater , David Restrepo

We present a new and efficient computational framework for uncertainty quantification (UQ) of critical buckling loads and knockdown factors for structures with stochastic imperfections. Traditional Monte Carlo (MC)-based methods require significant resources to evaluate knockdown factors across many geometric configurations, particularly for imperfection-sensitive structures. To address this challenge, we combine Hypercomplex Automatic Differentiation (HYPAD) with the Finite Element Method (FEM) to construct reduced-order models (ROMs) via Taylor Series Expansion. Additionally, we introduce a Chebyshev polynomial representation of random geometric imperfections to reduce the dimensionality of the input space, allowing UQ over a compact set of uncorrelated modal coefficients. We apply this method to a clamped-hinged circular arch and demonstrate that HYPAD-FEM achieves strong agreement with MC results while using only a single simulation. This results in a speed-up of approximately two orders of magnitude compared to

10^{4}

MC samples. The ROMs accurately capture critical buckling loads and knockdown factor distributions, with errors below 3% relative to MC across a range of geometrical configurations. Furthermore, the approach facilitates reliability-based design under uncertainty, enabling the efficient construction of design atlases and worst-case knockdown factor envelopes. By addressing the computational cost and dimensionality challenges inherent to imperfection-sensitive buckling analysis, this framework provides a practical tool for engineers to incorporate imperfection-induced uncertainty in structural design. The method is applicable to a range of engineering disciplines, including aerospace, civil, mechanical, and nuclear engineering, where high reliability is essential and traditional UQ approaches are computationally prohibitive.

我们提出了一种新的有效的计算框架，用于具有随机缺陷的结构的临界屈曲载荷和击倒因子的不确定性量化（UQ）。传统的基于蒙特卡罗（MC）的方法需要大量的资源来评估许多几何构型的击倒因子，特别是对于不完美敏感的结构。为了解决这一挑战，我们将超复杂自动微分（HYPAD）与有限元法（FEM）结合起来，通过泰勒级数展开构建了降阶模型（ROMs）。此外，我们引入随机几何缺陷的Chebyshev多项式表示来降低输入空间的维数，从而允许在紧致的一组不相关模态系数上实现UQ。我们将这种方法应用于一个夹铰圆拱，并证明了HYPAD-FEM在仅使用一次模拟的情况下与MC结果非常吻合。与104 MC样本相比，这导致了大约两个数量级的加速。ROMs能够准确捕获临界屈曲载荷和击倒因子分布，在各种几何构型下，相对于MC的误差低于3%。此外，该方法促进了不确定性下基于可靠性的设计，能够有效地构建设计图集和最坏情况击倒因子包络。通过解决缺陷敏感屈曲分析固有的计算成本和维度挑战，该框架为工程师在结构设计中纳入缺陷引起的不确定性提供了实用工具。该方法适用于一系列工程学科，包括航空航天、土木、机械和核工程，在这些学科中，高可靠性是必不可少的，而传统的UQ方法在计算上是禁止的。

{"title":"Efficient uncertainty quantification for critical buckling loads and determination of knockdown factors in nonlinear structures","authors":"David Y. Risk-Mora , Mauricio Aristizabal , Harry Millwater , David Restrepo","doi":"10.1016/j.ijsolstr.2025.113734","DOIUrl":"10.1016/j.ijsolstr.2025.113734","url":null,"abstract":"<div><div>We present a new and efficient computational framework for uncertainty quantification (UQ) of critical buckling loads and knockdown factors for structures with stochastic imperfections. Traditional Monte Carlo (MC)-based methods require significant resources to evaluate knockdown factors across many geometric configurations, particularly for imperfection-sensitive structures. To address this challenge, we combine Hypercomplex Automatic Differentiation (HYPAD) with the Finite Element Method (FEM) to construct reduced-order models (ROMs) via Taylor Series Expansion. Additionally, we introduce a Chebyshev polynomial representation of random geometric imperfections to reduce the dimensionality of the input space, allowing UQ over a compact set of uncorrelated modal coefficients. We apply this method to a clamped-hinged circular arch and demonstrate that HYPAD-FEM achieves strong agreement with MC results while using only a single simulation. This results in a speed-up of approximately two orders of magnitude compared to <span><math><mrow><msup><mrow><mn>10</mn></mrow><mn>4</mn></msup></mrow></math></span> MC samples. The ROMs accurately capture critical buckling loads and knockdown factor distributions, with errors below 3% relative to MC across a range of geometrical configurations. Furthermore, the approach facilitates reliability-based design under uncertainty, enabling the efficient construction of design atlases and worst-case knockdown factor envelopes. By addressing the computational cost and dimensionality challenges inherent to imperfection-sensitive buckling analysis, this framework provides a practical tool for engineers to incorporate imperfection-induced uncertainty in structural design. The method is applicable to a range of engineering disciplines, including aerospace, civil, mechanical, and nuclear engineering, where high reliability is essential and traditional UQ approaches are computationally prohibitive.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"325 ","pages":"Article 113734"},"PeriodicalIF":3.8,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental investigation of the mode I fracture energy of wood using DIC and secant compliance techniques and its numerical validation 基于DIC和割线柔度技术的木材I型断裂能试验研究及其数值验证

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-10-30 DOI: 10.1016/j.ijsolstr.2025.113735

Marek Romanowicz, Maciej Grygorczuk

The mode I propagation of cracks in pinewood is investigated through conducting cyclic loading–unloading tests on double cantilever beam specimens and monitoring crack growth by digital image correlation technique. Different procedures for determining fracture energy based on the secant compliance are applied and compared with each other, providing a key novelty in this paper. No differences in the average fracture energy extracted from three different crack measurement-based schemes and a small difference between them and the crack equivalent-based scheme were detected. The different experimental approaches were validated by finite element simulations using a bilinear cohesive zone model and a discrete measure of the crack length.

通过双悬臂梁试件的循环加卸载试验和数字图像相关技术监测松材裂纹扩展，研究了松材裂纹的I型扩展。采用并比较了基于割线柔度确定断裂能的不同方法，这是本文的一个关键新颖之处。三种基于裂纹测量的方案提取的平均断裂能无差异，且与基于裂纹当量的方案差异较小。采用双线性黏结区模型和裂缝长度的离散测量方法进行有限元模拟，验证了不同的实验方法。

引用次数: 0

Bridging a gap: A heavy elastica between point supports 弥合缝隙：点支撑物之间的一种很重的弹性材料

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-10-29 DOI: 10.1016/j.ijsolstr.2025.113702

Grace K. Curtis, Ian M. Griffiths, Dominic Vella

We study the deformation and slip-through of a heavy elastic beam suspended above two point supports and subject to an increasing body force — an idealized model of a fibre trapped in the pores of a filter as flow strength increases, for example. Using both asymptotic and numerical techniques, we investigate the behaviour of the beam under increasing body force and the maximum force that can be supported before it must slip between the supports. We quantify this maximum body force as a function of the separation between the two supports. Surprisingly, we show the existence of a critical separation below which the beam can withstand an arbitrarily large body force, even in the absence of friction. This is understood as the limit of a catenary between the supports that is connected to (and supported by the tension in) a vertically hanging portion outside the supports. We explore how frictional forces impact the deformation and load-bearing capacity of the beam and show that our results are consistent with laboratory experiments.

我们研究了悬挂在两点支撑物上的重弹性梁的变形和滑移，并受到不断增加的体力的影响——例如，随着流动强度的增加，纤维被困在过滤器孔中的理想模型。使用渐近和数值技术，我们研究了梁在增加的体力和在它必须在支撑之间滑动之前可以支持的最大力下的行为。我们将这个最大的身体力量化为两个支撑物之间距离的函数。令人惊讶的是，我们展示了一个临界分离的存在，在这个临界分离之下，即使在没有摩擦的情况下，梁也能承受任意大的体力。这被理解为连接到支撑外的垂直悬挂部分（并由张力支持）的支撑之间的悬链线的极限。我们探讨了摩擦力如何影响梁的变形和承载能力，并表明我们的结果与实验室实验一致。

引用次数: 0