International Journal of Solids and Structures最新文献_第7页

Constrained swelling of stretchable ionic conductors with compliant encapsulations 柔性封装可拉伸离子导体的约束膨胀

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-08 DOI: 10.1016/j.ijsolstr.2025.113806

Qingxian Li, Canhui Yang

Stretchable ionic conductors such as ionic hydrogels are the key functional materials for emerging applications, yet they are susceptible to composition fluctuation caused by swelling, which adversely alters their mechanical and electrical properties and limits their utility. Encapsulation with an elastomeric coating offers an effective means to suppress excessive swelling, however, the absence of quantitative mechanics analysis has significantly hindered rational designs and broader applications. Herein, we develop a theoretical model for the constrained swelling of an encapsulated structure comprising a cylindrical ionic conductor core and a non-absorbing elastomeric coating. We analyze the mechanics at equilibrium, providing quantitative insights into the deformation and stress fields, osmotic pressure, and solvent concentration distribution. The influence of key parameters—such as the modulus and thickness of the coating, the modulus and solvent-polymer affinity of the ionic conductor, environmental chemical potential and externally applied loads—on equilibrium solvent uptake is systematically evaluated. The proposed model elucidates the fundamental principles underlying compliantly constrained swelling in stretchable ionic conductors, thereby offering a robust theoretical foundation for the design and application of encapsulated ionic devices.

可拉伸离子导体（如离子水凝胶）是新兴应用的关键功能材料，但它们容易受到膨胀引起的成分波动的影响，这对其机械和电气性能产生不利影响，限制了它们的应用。弹性体涂层的封装提供了抑制过度膨胀的有效手段，然而，缺乏定量力学分析严重阻碍了合理的设计和更广泛的应用。在此，我们建立了一个由圆柱形离子导体核心和非吸收弹性涂层组成的封装结构的约束膨胀的理论模型。我们分析了平衡状态下的力学，提供了对变形和应力场、渗透压和溶剂浓度分布的定量见解。系统地评价了涂层的模量和厚度、离子导体的模量和溶剂-聚合物亲和性、环境化学势和外源载荷等关键参数对平衡溶剂吸收的影响。该模型阐明了可拉伸离子导体中顺从约束膨胀的基本原理，从而为封装离子器件的设计和应用提供了坚实的理论基础。

{"title":"Constrained swelling of stretchable ionic conductors with compliant encapsulations","authors":"Qingxian Li, Canhui Yang","doi":"10.1016/j.ijsolstr.2025.113806","DOIUrl":"10.1016/j.ijsolstr.2025.113806","url":null,"abstract":"<div><div>Stretchable ionic conductors such as ionic hydrogels are the key functional materials for emerging applications, yet they are susceptible to composition fluctuation caused by swelling, which adversely alters their mechanical and electrical properties and limits their utility. Encapsulation with an elastomeric coating offers an effective means to suppress excessive swelling, however, the absence of quantitative mechanics analysis has significantly hindered rational designs and broader applications. Herein, we develop a theoretical model for the constrained swelling of an encapsulated structure comprising a cylindrical ionic conductor core and a non-absorbing elastomeric coating. We analyze the mechanics at equilibrium, providing quantitative insights into the deformation and stress fields, osmotic pressure, and solvent concentration distribution. The influence of key parameters—such as the modulus and thickness of the coating, the modulus and solvent-polymer affinity of the ionic conductor, environmental chemical potential and externally applied loads—on equilibrium solvent uptake is systematically evaluated. The proposed model elucidates the fundamental principles underlying compliantly constrained swelling in stretchable ionic conductors, thereby offering a robust theoretical foundation for the design and application of encapsulated ionic devices.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113806"},"PeriodicalIF":3.8,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145836735","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

Equilibrium theory and matrix analysis of tensegrity-beam structures 张拉整体梁结构的平衡理论与矩阵分析

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-06 DOI: 10.1016/j.ijsolstr.2025.113805

Shuo Ma , Doris R. Swai , Jiaxing Tang , Yongcan Dong , Xingfei Yuan

The integration of beam elements into tensegrity structures enhances the mechanical behavior while reducing the complexity of nodal connections in classical tensegrities. This study introduces the equilibrium theory of tensegrity-beam structures and investigates the prestress and mechanism characteristics based on the matrix decomposition of the equilibrium and compatibility matrices. The notations of the tensegrity-beam structures are given to describe the position and connection of all members. The stiffness matrix of a beam element is decomposed to obtain the self-stress modes and mechanism modes of a beam element. The equilibrium equations are derived from the principle of stationary total potential energy, and the equilibrium matrix is obtained by combining the linearized equilibrium equation and member force constraints. The compatibility matrix is derived from the kinematics relationship and the mechanism constraints. The prestress modes and mechanism modes are obtained based on the singular value decomposition of the equilibrium and compatibility matrix. The equilibrium theory can be simply extended to three dimensional structures. Numerical validation is conducted through three examples, comparing the proposed method’s results with both analytical solutions and finite element simulations. The comparative analysis confirms the method’s accuracy and efficiency.

将梁单元集成到张拉整体结构中，提高了经典张拉整体结构的力学性能，同时降低了节点连接的复杂性。本文介绍了张拉整体梁结构的平衡理论，并基于平衡矩阵和相容性矩阵的矩阵分解，研究了张拉整体梁结构的预应力和受力机理特征。给出了张拉整体梁结构的符号来描述所有构件的位置和连接。对梁单元的刚度矩阵进行分解，得到梁单元的自应力模态和机构模态。根据稳态总势能原理推导出平衡方程，将线性化的平衡方程与构件受力约束相结合得到平衡矩阵。由运动学关系和机构约束推导出相容矩阵。基于平衡矩阵和相容性矩阵的奇异值分解，得到了预应力模态和机制模态。平衡理论可以简单地推广到三维结构中。通过三个算例进行了数值验证，将所提方法的结果与解析解和有限元模拟结果进行了比较。对比分析证实了该方法的准确性和有效性。

{"title":"Equilibrium theory and matrix analysis of tensegrity-beam structures","authors":"Shuo Ma , Doris R. Swai , Jiaxing Tang , Yongcan Dong , Xingfei Yuan","doi":"10.1016/j.ijsolstr.2025.113805","DOIUrl":"10.1016/j.ijsolstr.2025.113805","url":null,"abstract":"<div><div>The integration of beam elements into tensegrity structures enhances the mechanical behavior while reducing the complexity of nodal connections in classical tensegrities. This study introduces the equilibrium theory of tensegrity-beam structures and investigates the prestress and mechanism characteristics based on the matrix decomposition of the equilibrium and compatibility matrices. The notations of the tensegrity-beam structures are given to describe the position and connection of all members. The stiffness matrix of a beam element is decomposed to obtain the self-stress modes and mechanism modes of a beam element. The equilibrium equations are derived from the principle of stationary total potential energy, and the equilibrium matrix is obtained by combining the linearized equilibrium equation and member force constraints. The compatibility matrix is derived from the kinematics relationship and the mechanism constraints. The prestress modes and mechanism modes are obtained based on the singular value decomposition of the equilibrium and compatibility matrix. The equilibrium theory can be simply extended to three dimensional structures. Numerical validation is conducted through three examples, comparing the proposed method’s results with both analytical solutions and finite element simulations. The comparative analysis confirms the method’s accuracy and efficiency.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113805"},"PeriodicalIF":3.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749212","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 evaluation of a hyperelastic-viscoplastic constitutive model for packaging adhesives: Comparison with deep learning methods 包装胶粘剂超弹粘塑性本构模型的实验评价：与深度学习方法的比较

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-05 DOI: 10.1016/j.ijsolstr.2025.113804

Siyu He , Feixiang Tang , Li Yang , Fanliang Li , Xiaoping Wang , Sheng Liu

Currently, most constitutive models for silicone adhesives consider their viscoelastic and nonlinear characteristics, while often neglecting the potential influence of plasticity on their mechanical properties. In this study, back stresses in the viscoplastoc model are used to characterize the plastic behavior of silicone adhesives. A temperature-dependent hyperelastic-viscoplastic multi-component model is proposed to investigate the mechanical behavior of silicone adhesives at different temperatures. This model refers to a constitutive model developed to characterize the complex mechanical behavior of materials, particularly those exhibiting hyperelastic-viscoplastic properties. Meanwhile, a deep learning model is employed to learn the patterns of mechanical behavior changes across different temperatures. The deep learning model and the hyperelastic-viscoplastic model are then used to predict results at other temperatures and the predictions from both models show good agreement. Additionally, Abaqus simulations of the adhesive’s service environment are conducted and the simulation results are consistent with theoretical predictions. This model proposed in this study may serve as a new constitutive model for adhesives.

目前，大多数有机硅胶粘剂的本构模型考虑了其粘弹性和非线性特性，而往往忽略了塑性对其力学性能的潜在影响。在本研究中，背应力在粘塑性模型中被用来表征硅胶胶粘剂的塑性行为。提出了一种温度相关的超弹粘塑性多组分模型，研究了硅酮胶粘剂在不同温度下的力学行为。该模型是指一种本构模型，用于描述材料的复杂力学行为，特别是那些表现出超弹粘塑性特性的材料。同时，采用深度学习模型学习不同温度下的力学行为变化模式。然后使用深度学习模型和超弹粘塑性模型来预测其他温度下的结果，两个模型的预测结果显示出很好的一致性。此外，对胶粘剂的使用环境进行了Abaqus仿真，仿真结果与理论预测一致。该模型可作为胶粘剂的一种新的本构模型。

{"title":"Experimental evaluation of a hyperelastic-viscoplastic constitutive model for packaging adhesives: Comparison with deep learning methods","authors":"Siyu He , Feixiang Tang , Li Yang , Fanliang Li , Xiaoping Wang , Sheng Liu","doi":"10.1016/j.ijsolstr.2025.113804","DOIUrl":"10.1016/j.ijsolstr.2025.113804","url":null,"abstract":"<div><div>Currently, most constitutive models for silicone adhesives consider their viscoelastic and nonlinear characteristics, while often neglecting the potential influence of plasticity on their mechanical properties. In this study, back stresses in the viscoplastoc model are used to characterize the plastic behavior of silicone adhesives. A temperature-dependent hyperelastic-viscoplastic multi-component model is proposed to investigate the mechanical behavior of silicone adhesives at different temperatures. This modelrefers to a constitutive model developed to characterize the complex mechanical behavior of materials, particularly those exhibitinghyperelastic-viscoplasticproperties. Meanwhile, a deep learning model is employed to learn the patterns of mechanical behavior changes across different temperatures. The deep learning model and the hyperelastic-viscoplastic model are then used to predict results at other temperatures and the predictions from both models show good agreement. Additionally, Abaqus simulations of the adhesive’s service environment are conducted and the simulation results are consistent with theoretical predictions. This model proposed in this study may serve as a new constitutive model for adhesives.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113804"},"PeriodicalIF":3.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749210","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

Finite-deflection peeling of elastic films with adhesive heterogeneity 粘接非均质弹性膜的有限挠曲剥落

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-05 DOI: 10.1016/j.ijsolstr.2025.113803

Xuebo Yuan

Film–substrate systems are ubiquitous in biological adhesion, multi-chip packaging, flexible electronics, and nanomaterials, with peeling behavior directly influencing structural stability and functionality. However, the peeling mechanics of films with adhesive heterogeneity are not yet fully understood. In this work, the peeling behavior of elastic films with spatially varying adhesion under a vertical peeling force, bonded to a rigid substrate, is investigated. Based on the principle of minimum potential energy, a large-deformation mechanics model for peeling heterogeneous films is developed within finite deflection and validated using molecular dynamics simulations. The results show that adhesive heterogeneity can markedly influence the evolution of the peeling force. When the peeling front traverses segments with different adhesion toughness, the resulting increase or decrease in peeling force depends on the segment adhesion, segment length, and overall geometrical proportions. Periodically heterogeneous films exhibit oscillatory peeling forces, with amplitudes regulated by the period length and adhesive distribution, which can be approximated by a homogeneous film with equivalent adhesion toughness. The variations in peeling force primarily result from the redistribution of bending energy within the film and the work required to overcome interfacial interactions. The findings provide a theoretical foundation for tuning the peeling behavior of film–substrate systems.

薄膜-衬底系统在生物粘附、多芯片封装、柔性电子和纳米材料中无处不在，剥离行为直接影响其结构稳定性和功能。然而，具有黏合剂非均质性的薄膜的剥离机理尚未完全了解。在这项工作中，研究了具有空间变化的粘附力的弹性薄膜在垂直剥离力作用下与刚性衬底结合的剥离行为。基于最小势能原理，建立了非均质薄膜在有限挠度下剥落的大变形力学模型，并通过分子动力学模拟进行了验证。结果表明，胶粘剂的非均质性对剥离力的演化有显著影响。当剥离前端穿过不同粘附韧性的线段时，剥离力的增加或减少取决于线段的粘附力、线段长度和整体几何比例。周期性非均质膜表现出振荡剥离力，其振幅受周期长度和胶粘剂分布的调节，可以近似为具有等效粘附韧性的均匀膜。剥离力的变化主要是由于薄膜内弯曲能量的重新分配和克服界面相互作用所需的功。研究结果为调整薄膜-衬底体系的剥离行为提供了理论基础。

{"title":"Finite-deflection peeling of elastic films with adhesive heterogeneity","authors":"Xuebo Yuan","doi":"10.1016/j.ijsolstr.2025.113803","DOIUrl":"10.1016/j.ijsolstr.2025.113803","url":null,"abstract":"<div><div>Film–substrate systems are ubiquitous in biological adhesion, multi-chip packaging, flexible electronics, and nanomaterials, with peeling behavior directly influencing structural stability and functionality. However, the peeling mechanics of films with adhesive heterogeneity are not yet fully understood. In this work, the peeling behavior of elastic films with spatially varying adhesion under a vertical peeling force, bonded to a rigid substrate, is investigated. Based on the principle of minimum potential energy, a large-deformation mechanics model for peeling heterogeneous films is developed within finite deflection and validated using molecular dynamics simulations. The results show that adhesive heterogeneity can markedly influence the evolution of the peeling force. When the peeling front traverses segments with different adhesion toughness, the resulting increase or decrease in peeling force depends on the segment adhesion, segment length, and overall geometrical proportions. Periodically heterogeneous films exhibit oscillatory peeling forces, with amplitudes regulated by the period length and adhesive distribution, which can be approximated by a homogeneous film with equivalent adhesion toughness. The variations in peeling force primarily result from the redistribution of bending energy within the film and the work required to overcome interfacial interactions. The findings provide a theoretical foundation for tuning the peeling behavior of film–substrate systems.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113803"},"PeriodicalIF":3.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749211","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

A high-order 2D-plate macro-element model for the analysis of bonded joints 基于高阶二维板宏观单元模型的粘结节点分析

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-04 DOI: 10.1016/j.ijsolstr.2025.113787

Marcello Calì , Sébastien Schwartz , Frédéric Lachaud , Sofia Teixeira De Freitas , Éric Paroissien

Adhesive bonding has emerged as an attractive solution for the joining of lightweight structures, yet accurate stress analysis remains computationally demanding when relying on Finite Elements (FE). This paper introduces a novel plate Macro-Element (ME) formulation that extends previous beam-type approaches to enable three-dimensional stress analysis of bonded joints. High-order polynomial expansions are employed to describe the displacement field of the adherends, while the adhesive is modeled as an elastic foundation. Governing equations are derived using a variational principle and integrated within a standard FE framework. Through the derivation of a special stiffness matrix, a ME can simulate an entire overlap with just one element. The proposed methodology is validated against FE results for a single-lap bonded joint with a thin adhesive layer. The influence of different higher-order displacement assumptions and constitutive models is investigated. The results show that their inclusion in the formulation improves the solution accuracy.

粘接已成为轻型结构连接的一种有吸引力的解决方案，然而，当依赖于有限元（FE）时，精确的应力分析仍然需要计算。本文介绍了一种新的板宏观单元（ME）公式，该公式扩展了以前的梁式方法，以实现粘接节点的三维应力分析。采用高次多项式展开来描述黏合剂的位移场，将黏合剂建模为弹性基础。利用变分原理推导了控制方程，并将其集成到标准有限元框架中。通过推导一个特殊的刚度矩阵，有限元可以模拟一个单元的整个重叠。针对具有薄粘接层的单搭接接头的有限元结果验证了所提出的方法。研究了不同高阶位移假设和本构模型的影响。结果表明，它们的加入提高了溶液的精度。

{"title":"A high-order 2D-plate macro-element model for the analysis of bonded joints","authors":"Marcello Calì , Sébastien Schwartz , Frédéric Lachaud , Sofia Teixeira De Freitas , Éric Paroissien","doi":"10.1016/j.ijsolstr.2025.113787","DOIUrl":"10.1016/j.ijsolstr.2025.113787","url":null,"abstract":"<div><div>Adhesive bonding has emerged as an attractive solution for the joining of lightweight structures, yet accurate stress analysis remains computationally demanding when relying on Finite Elements (FE). This paper introduces a novel plate Macro-Element (ME) formulation that extends previous beam-type approaches to enable three-dimensional stress analysis of bonded joints. High-order polynomial expansions are employed to describe the displacement field of the adherends, while the adhesive is modeled as an elastic foundation. Governing equations are derived using a variational principle and integrated within a standard FE framework. Through the derivation of a special stiffness matrix, a ME can simulate an entire overlap with just one element. The proposed methodology is validated against FE results for a single-lap bonded joint with a thin adhesive layer. The influence of different higher-order displacement assumptions and constitutive models is investigated. The results show that their inclusion in the formulation improves the solution accuracy.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113787"},"PeriodicalIF":3.8,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692250","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

Microscale strain field predictions from grain microstructure of polycrystalline metals using fully convolutional networks 利用全卷积网络预测多晶金属晶粒微观结构的微尺度应变场

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-03 DOI: 10.1016/j.ijsolstr.2025.113801

William Noh , Renato Bichara Vieira , John Lambros , Huck Beng Chew

Under deformation, the heterogeneous microstructure of polycrystalline metals generates complex strain variations at the microscale, which ultimately control failure mechanisms. Here, we train a fully convolutional network (FCN) on numerical datasets generated by crystal plasticity finite element simulations (CPFEMs) to predict the two-dimensional (2D) patterns of strain field variations (output) from grain orientation information (input) at the microscale, across a large subset of grain morphologies. Previously applied FCN architectures have correctly predicted the general patterns of strain distributions, but with performance that saturates quickly with increasing size of the training dataset. We overcome this limitation by augmenting the traditional convolution architecture with modern architectural elements such as skip connections, depth-wise separable convolutions, residual functions, and inverted bottleneck convolution modules, reducing the number of trainable parameters and floating-point operations by 88% and 77%, respectively. Our FCN architecture, trained on predominantly equiaxed grains with a fixed (lognormal) distribution of grain sizes under a small subset of macroscopic strain states, is capable of interpolation and limited extrapolation to other strain states. Its ability to predict the microscale strain patterns across a wide range of grain sizes, grain distributions, and grain shapes without retraining, further suggests its generalizability to different grain architectures. Finally, we discuss the utility of transfer learning to reduce the amount of training data required to adapt the FCN to materials with different stress–strain response.

在变形作用下，多晶金属的异质微观结构在微观尺度上产生复杂的应变变化，最终控制失效机制。在这里，我们在晶体塑性有限元模拟（cpfem）生成的数值数据集上训练了一个全卷积网络（FCN），以预测微观尺度下晶粒取向信息（输入）的二维（2D）应变场变化（输出）模式，跨越大量晶粒形态子集。以前应用的FCN架构已经正确地预测了应变分布的一般模式，但随着训练数据集规模的增加，性能会迅速饱和。我们通过使用现代架构元素（如跳过连接、深度可分离卷积、残差函数和反向瓶颈卷积模块）来增强传统卷积架构，从而克服了这一限制，将可训练参数和浮点运算的数量分别减少了88%和77%。我们的FCN架构主要训练在宏观应变状态的一小部分下具有固定（对数正态）晶粒尺寸分布的等轴晶粒，能够插值和有限的外推到其他应变状态。它能够在不需要再训练的情况下预测大范围晶粒尺寸、晶粒分布和晶粒形状的微尺度应变模式，进一步表明它可以推广到不同的晶粒结构。最后，我们讨论了迁移学习的效用，以减少使FCN适应具有不同应力-应变响应的材料所需的训练数据量。

{"title":"Microscale strain field predictions from grain microstructure of polycrystalline metals using fully convolutional networks","authors":"William Noh , Renato Bichara Vieira , John Lambros , Huck Beng Chew","doi":"10.1016/j.ijsolstr.2025.113801","DOIUrl":"10.1016/j.ijsolstr.2025.113801","url":null,"abstract":"<div><div>Under deformation, the heterogeneous microstructure of polycrystalline metals generates complex strain variations at the microscale, which ultimately control failure mechanisms. Here, we train a fully convolutional network (FCN) on numerical datasets generated by crystal plasticity finite element simulations (CPFEMs) to predict the two-dimensional (2D) patterns of strain field variations (output) from grain orientation information (input) at the microscale, across a large subset of grain morphologies. Previously applied FCN architectures have correctly predicted the general patterns of strain distributions, but with performance that saturates quickly with increasing size of the training dataset. We overcome this limitation by augmenting the traditional convolution architecture with modern architectural elements such as skip connections, depth-wise separable convolutions, residual functions, and inverted bottleneck convolution modules, reducing the number of trainable parameters and floating-point operations by 88% and 77%, respectively. Our FCN architecture, trained on predominantly equiaxed grains with a fixed (lognormal) distribution of grain sizes under a small subset of macroscopic strain states, is capable of interpolation and limited extrapolation to other strain states. Its ability to predict the microscale strain patterns across a wide range of grain sizes, grain distributions, and grain shapes without retraining, further suggests its generalizability to different grain architectures. Finally, we discuss the utility of transfer learning to reduce the amount of training data required to adapt the FCN to materials with different stress–strain response.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113801"},"PeriodicalIF":3.8,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797630","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 analysis of a confined chiral rod and its application to DNA packaging 受限手性棒的屈曲分析及其在DNA包装中的应用

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-02 DOI: 10.1016/j.ijsolstr.2025.113797

Xiaofei Wang , Huichuan Zhao , Ryuichi Tarumi , Takayuki Kitamura , Jianshan Wang

Chiral biological filaments, such as DNA and chromatin fibers, are commonly found in crowded environments. The buckling of these filaments plays a crucial role in determining the morphologies of their packaging structures. This study examines the buckling of a chiral rod confined within a cylindrical domain through Kirchhoff’s dynamic analogy. Using the chiral rod model incorporating bend-twist coupling deformations, we derive the fixed-point paths for both constrained and unconstrained cases, and identify the buckling configurations corresponding to both helical and localized solutions, along with the constraining forces. We quantitatively analyze the effects of chiral microstructures and load parameters on the buckling configurations and corresponding constraining forces. Furthermore, we apply the developed model of confined chiral rod to DNA packaging. The helical configuration of DNA and its load-package ratio are derived and show good agreement with experimental data. Our study found that the bend-twist coupling deformation can effectively soften the rod and thereby induce tighter helical configurations. Moreover, clearly different to the non-chiral rod, the preference to the twisting with specific handedness of chiral rod causes a shift in the saddle point path and makes the rod form helical structures at both ends of the configuration corresponding to localized solution. The material chirality, to a large extent, determines the inner surface of cylinder whether attracts or supports the chiral rod. This study not only provides new insights into the buckling of chiral biological filaments but also contributes to the understanding of the formation of complex packaging structures.

手性生物细丝，如DNA和染色质纤维，通常在拥挤的环境中发现。这些长丝的屈曲在决定其包装结构的形态方面起着至关重要的作用。本研究通过基尔霍夫的动力学类比研究了限制在圆柱形域内的手性棒的屈曲。利用包含弯扭耦合变形的手性杆模型，导出了约束和无约束情况下的不动点路径，并确定了螺旋解和局部解对应的屈曲构型以及约束力。定量分析了手性微观结构和载荷参数对屈曲构型和相应的约束力的影响。此外，我们将开发的受限手性棒模型应用于DNA包装。推导了DNA的螺旋结构及其载包比，结果与实验数据吻合较好。我们的研究发现，弯扭耦合变形可以有效地软化杆，从而诱导更紧密的螺旋结构。此外，与非手性杆明显不同的是，手性杆偏爱具有特定手性的扭转，导致鞍点路径发生移位，使杆在构型两端形成与定域解相对应的螺旋结构。材料的手性在很大程度上决定了筒体内表面是否吸引或支撑手性杆。这项研究不仅为手性生物丝的屈曲提供了新的见解，而且有助于理解复杂包装结构的形成。

{"title":"Buckling analysis of a confined chiral rod and its application to DNA packaging","authors":"Xiaofei Wang , Huichuan Zhao , Ryuichi Tarumi , Takayuki Kitamura , Jianshan Wang","doi":"10.1016/j.ijsolstr.2025.113797","DOIUrl":"10.1016/j.ijsolstr.2025.113797","url":null,"abstract":"<div><div>Chiral biological filaments, such as DNA and chromatin fibers, are commonly found in crowded environments. The buckling of these filaments plays a crucial role in determining the morphologies of their packaging structures. This study examines the buckling of a chiral rod confined within a cylindrical domain through Kirchhoff’s dynamic analogy. Using the chiral rod model incorporating bend-twist coupling deformations, we derive the fixed-point paths for both constrained and unconstrained cases, and identify the buckling configurations corresponding to both helical and localized solutions, along with the constraining forces. We quantitatively analyze the effects of chiral microstructures and load parameters on the buckling configurations and corresponding constraining forces. Furthermore, we apply the developed model of confined chiral rod to DNA packaging. The helical configuration of DNA and its load-package ratio are derived and show good agreement with experimental data. Our study found that the bend-twist coupling deformation can effectively soften the rod and thereby induce tighter helical configurations. Moreover, clearly different to the non-chiral rod, the preference to the twisting with specific handedness of chiral rod causes a shift in the saddle point path and makes the rod form helical structures at both ends of the configuration corresponding to localized solution. The material chirality, to a large extent, determines the inner surface of cylinder whether attracts or supports the chiral rod. This study not only provides new insights into the buckling of chiral biological filaments but also contributes to the understanding of the formation of complex packaging structures.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113797"},"PeriodicalIF":3.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797635","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

New buckling analysis of plate assemblies: Analytical solutions 新的板组件屈曲分析：解析解

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-12-01 DOI: 10.1016/j.ijsolstr.2025.113799

Zhaoyang Hu , Rui Li

This work introduces novel analytical solutions for the buckling of non-Lévy-type plate assemblies with line hinges and line supports, overcoming the constraints of current methods that concentrate primarily on Lévy-type cases. By utilizing the domain partitioning, we effectively divide plate assemblies into subplates free of internal discontinuities, facilitating the application of the symplectic superposition to derive analytical solutions with satisfactory convergence. Comparisons with the finite element method and the Ritz method confirm the reliability of the obtained buckling solutions. Comprehensive parametric studies reveal the significant effects of the hinge/support positions and the aspect ratios on the critical buckling loads. Moreover, the analytical framework developed in this paper is versatile enough to accommodate mixed boundary conditions and can be extended to thermal buckling. This research not only fills a gap in the existing literature but also deepens the understanding of buckling phenomena in line-hinged and line-supported plate assemblies.

本文介绍了具有线铰链和线支撑的非l型板组件的屈曲的新的分析解决方案，克服了目前主要集中在l型情况下的方法的限制。通过区域划分，我们有效地将板块组合划分为没有内部不连续的子板块，从而便于应用辛叠加导出收敛性令人满意的解析解。通过与有限元法和Ritz法的比较，验证了所得屈曲解的可靠性。综合参数研究表明，铰/支承位置和长径比对临界屈曲载荷有显著影响。此外，本文建立的分析框架具有足够的通用性，可以适应混合边界条件，并可以扩展到热屈曲。本研究不仅填补了现有文献的空白，而且加深了对线铰和线支板组合的屈曲现象的理解。

引用次数: 0

Mechanics of shape-programmable network structure actuated by electromagnetic force 电磁力驱动的形状可编程网络结构力学

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-29 DOI: 10.1016/j.ijsolstr.2025.113798

Yunmeng Nie , Xiangyu Lu , Weixin Zhou , Ying Chen , Heling Wang , Xue Feng

Shape-programmable structures capable of morphing into various configurations in response to spatiotemporally distributed actuation exhibit emerging applications in soft robots, smart medicine and human–machine interfaces. Previously reported shape-programmable structures encounter difficulties in reproducing multiple target shapes and continuous shape-shifting processes, due to the lack of strategy to determine the distribution of actuations for the structure to morph into targets (i.e., the inverse problem). A recently developed network structure formed by interconnected serpentine traces with metals demonstrates complex shape morphing, under the actuation of distributed electromagnetic forces. However, the associated solution to the inverse problem relies on finite element analysis (FEA), which is computationally expensive especially when the number of serpentines in the structure increases. Here, a mechanics model in concise form is developed for the out-of-plane deformation of the electromagnetically actuated network structure. It shows that the overall large deformation obeys the same rule as that of a tensioned membrane under out-of-plane pressure in linear regime, yielding analytical solutions to the relationship of displacement vs. electromagnetic force. The model is validated by FEA and experiments for various typical deformations. It leads to a model-based solution to the inverse problem, predicting the actuations for the structure to morph into target shapes without referring to expensive numerical approaches. In addition, the model reveals the mechanism of the shape programmable network structure and provides design guidelines. These findings pave the way for the application of shape programmable soft surface, especially for scenario that demands the accurate control of the shape-shifting process.

形状可编程结构能够响应时空分布的驱动而变形成各种配置，在软机器人、智能医疗和人机界面中表现出新兴的应用。先前报道的形状可编程结构在再现多个目标形状和连续变形过程中遇到困难，这是由于缺乏确定结构变形为目标的驱动分布的策略（即逆问题）。最近开发的由相互连接的蛇形迹线与金属形成的网络结构在分布式电磁力的驱动下表现出复杂的形状变形。然而，反问题的相关解依赖于有限元分析（FEA），特别是当结构中蛇形体的数量增加时，计算成本很高。本文建立了电磁驱动网络结构面外变形的简明力学模型。结果表明，薄膜在平面外压力作用下的整体大变形与薄膜在线性状态下的大变形遵循相同的规律，得到了位移与电磁力关系的解析解。通过有限元分析和各种典型变形试验对模型进行了验证。它导致了一个基于模型的反问题的解决方案，预测结构变形成目标形状的驱动，而不参考昂贵的数值方法。此外，该模型揭示了形状可编程网络结构的机理，并提供了设计指导。这些发现为形状可编程软表面的应用铺平了道路，特别是在需要精确控制变形过程的场景中。

{"title":"Mechanics of shape-programmable network structure actuated by electromagnetic force","authors":"Yunmeng Nie , Xiangyu Lu , Weixin Zhou , Ying Chen , Heling Wang , Xue Feng","doi":"10.1016/j.ijsolstr.2025.113798","DOIUrl":"10.1016/j.ijsolstr.2025.113798","url":null,"abstract":"<div><div>Shape-programmable structures capable of morphing into various configurations in response to spatiotemporally distributed actuation exhibit emerging applications in soft robots, smart medicine and human–machine interfaces. Previously reported shape-programmable structures encounter difficulties in reproducing multiple target shapes and continuous shape-shifting processes, due to the lack of strategy to determine the distribution of actuations for the structure to morph into targets (i.e., the inverse problem). A recently developed network structure formed by interconnected serpentine traces with metals demonstrates complex shape morphing, under the actuation of distributed electromagnetic forces. However, the associated solution to the inverse problem relies on finite element analysis (FEA), which is computationally expensive especially when the number of serpentines in the structure increases. Here, a mechanics model in concise form is developed for the out-of-plane deformation of the electromagnetically actuated network structure. It shows that the overall large deformation obeys the same rule as that of a tensioned membrane under out-of-plane pressure in linear regime, yielding analytical solutions to the relationship of displacement vs. electromagnetic force. The model is validated by FEA and experiments for various typical deformations. It leads to a model-based solution to the inverse problem, predicting the actuations for the structure to morph into target shapes without referring to expensive numerical approaches. In addition, the model reveals the mechanism of the shape programmable network structure and provides design guidelines. These findings pave the way for the application of shape programmable soft surface, especially for scenario that demands the accurate control of the shape-shifting process.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113798"},"PeriodicalIF":3.8,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145797634","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

A semi-analytical bridging model for assessing energy dissipation of monolithic and hybrid z-pins in composite laminates 基于半解析桥接模型的复合材料层合板单片和混合z销耗能评估

IF 3.8 3区工程技术 Q1 MECHANICS

International Journal of Solids and Structures

Pub Date : 2025-11-28 DOI: 10.1016/j.ijsolstr.2025.113790

L.F. Varandas, A.R. Melro, G. Allegri, S.R. Hallett

A semi-analytical model is proposed to simulate the bridging behaviour of novel z-pin materials and architectures recently developed to ensure balanced mode I to mode II delamination bridging. The computational model describes these z-pins as Timoshenko beams embedded in an elastic foundation representing the surrounding composite laminate. Governing equations for the behaviour of the z-pins are derived, with appropriate modifications made to the original formulation to account for the bridging actions of the novel z-pins. A genetic algorithm is proposed to calibrate the necessary input parameters of the model, based on the specific type of z-pin being considered. The model is validated through comparison with numerous experimental single z-pin datasets and effectively outputs the ultimate displacement and energy dissipated per unit area, normalised with respect to areal density, for future use in macroscopic modelling simulations, with the underlying assumptions and limitations explicitly acknowledged and discussed.

提出了一种半解析模型来模拟最近开发的新型z-pin材料和结构的桥接行为，以确保平衡的I模式到II模式分层桥接。计算模型将这些z形销描述为嵌入弹性基础中的Timoshenko梁，代表周围的复合层压板。对z销行为的控制方程进行了推导，并对原始公式进行了适当的修改，以考虑新型z销的桥接作用。针对z-pin的具体类型，提出了一种遗传算法来标定模型所需的输入参数。该模型通过与众多实验单z针数据集的比较进行了验证，并有效地输出了单位面积的最终位移和能量耗散，相对于面密度进行了归一化，以供未来宏观建模模拟使用，并明确承认和讨论了潜在的假设和限制。

引用次数: 0