This study proposes a coupling method that integrates local and nonlocal continuum mechanics to predict brittle fractures in functionally graded materials (FGMs). The main advantage of this approach is its ability to combine the strengths of classical continuum mechanics (CCM) and bond-based peridynamics (BPD), enabling accurate and efficient fracture simulations in FGMs. By establishing a pointwise equivalence of deformation energy density, an equivalent continuum mechanics model is derived from the bond-based peridynamic framework for FGMs and the relationship between the equivalent stiffness tensors and the micromodulus of the BPD model is formulated. These two models are then coupled into a unified system of equations, with a transition region introduced to ensure a smooth connection between them. The nonlocal BPD model is applied specifically to the fracture region, while the local CCM is employed in areas undergoing continuous deformation, thereby significantly reducing the computational cost of FGM fracture simulations. The convergence of the coupling model to CCM is demonstrated through rigorous mathematical analysis. Finally, the accuracy and efficiency of the coupling method are verified through two- and three-dimensional numerical examples.
{"title":"A energy-based coupling approach of peridynamic and classical continuum mechanics for FGM brittle fractures","authors":"Shaoqi Zheng , Yanfu Chen , Jiwei Zhang , Jieqiong Zhang , Zihao Yang","doi":"10.1016/j.ijsolstr.2025.113802","DOIUrl":"10.1016/j.ijsolstr.2025.113802","url":null,"abstract":"<div><div>This study proposes a coupling method that integrates local and nonlocal continuum mechanics to predict brittle fractures in functionally graded materials (FGMs). The main advantage of this approach is its ability to combine the strengths of classical continuum mechanics (CCM) and bond-based peridynamics (BPD), enabling accurate and efficient fracture simulations in FGMs. By establishing a pointwise equivalence of deformation energy density, an equivalent continuum mechanics model is derived from the bond-based peridynamic framework for FGMs and the relationship between the equivalent stiffness tensors and the micromodulus of the BPD model is formulated. These two models are then coupled into a unified system of equations, with a transition region introduced to ensure a smooth connection between them. The nonlocal BPD model is applied specifically to the fracture region, while the local CCM is employed in areas undergoing continuous deformation, thereby significantly reducing the computational cost of FGM fracture simulations. The convergence of the coupling model to CCM is demonstrated through rigorous mathematical analysis. Finally, the accuracy and efficiency of the coupling method are verified through two- and three-dimensional numerical examples.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113802"},"PeriodicalIF":3.8,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749205","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}
Pub Date : 2025-12-08DOI: 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.
{"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}
Pub Date : 2025-12-06DOI: 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.
{"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}
Pub Date : 2025-12-05DOI: 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.
{"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 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.</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}
Pub Date : 2025-12-05DOI: 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.
{"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}
Pub Date : 2025-12-04DOI: 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.
{"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}
Pub Date : 2025-12-03DOI: 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.
{"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}
Pub Date : 2025-12-02DOI: 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.
{"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}
Pub Date : 2025-12-01DOI: 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.
{"title":"New buckling analysis of plate assemblies: Analytical solutions","authors":"Zhaoyang Hu , Rui Li","doi":"10.1016/j.ijsolstr.2025.113799","DOIUrl":"10.1016/j.ijsolstr.2025.113799","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":14311,"journal":{"name":"International Journal of Solids and Structures","volume":"327 ","pages":"Article 113799"},"PeriodicalIF":3.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692251","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}
Pub Date : 2025-11-29DOI: 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.
{"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}