Pub Date : 2025-09-30DOI: 10.1016/j.ijengsci.2025.104392
Gennadi I. Mikhasev , Victor A. Eremeyev
Within the context of linear surface elasticity, we discuss the propagation of anti-plane surface waves, taking into account the anisotropy of the material. Here, we consider one of the most general crystal systems in the bulk, i.e. monoclinic symmetry. For the free surface, however, we consider rectangular symmetry. We derived the dispersion relations for three structures with surface energy: a half-space with a free surface; a layer of finite thickness; and a two-layered half-space. Surprisingly, these coincide with their isotropic counterparts, differing only in notation. Conversely, the anisotropy of the material in the bulk affects the displacement decay with depth. The pure exponential decay of displacements with the depth now transforms into decay with oscillations.
{"title":"On effect of anisotropy on anti-plane shear waves in elastic monoclinic half-space and plates","authors":"Gennadi I. Mikhasev , Victor A. Eremeyev","doi":"10.1016/j.ijengsci.2025.104392","DOIUrl":"10.1016/j.ijengsci.2025.104392","url":null,"abstract":"<div><div>Within the context of linear surface elasticity, we discuss the propagation of anti-plane surface waves, taking into account the anisotropy of the material. Here, we consider one of the most general crystal systems in the bulk, i.e. monoclinic symmetry. For the free surface, however, we consider rectangular symmetry. We derived the dispersion relations for three structures with surface energy: a half-space with a free surface; a layer of finite thickness; and a two-layered half-space. Surprisingly, these coincide with their isotropic counterparts, differing only in notation. Conversely, the anisotropy of the material in the bulk affects the displacement decay with depth. The pure exponential decay of displacements with the depth now transforms into decay with oscillations.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104392"},"PeriodicalIF":5.7,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145216510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A non-ordinary state-based peridynamic model(NOSBPD) is presented for linear piezoelectromagnetic material(PEM). The corresponding material model is developed by establishing the connection between the classical theory of piezoelectromagnetics and the newly proposed peridynamic framework. The variational approach and Hamiltonian principle are utilised to establish the equation of motion. This investigation shows the effectiveness of the proposed model to handle piezoelectromagnetic material. It is also shown that the considered stabilisation method effectively reduces the instabilities of NOSBPD. The dynamic behaviour of piezoelectromagnetic material in the proposed framework is investigated. The dispersion relations for stabilised versions of NOSBPD in one and two dimensions are established analytically for PEM. The graphs illustrate the influence of and different nonlocality functions on frequency, phase velocity, and group velocity. Also, the significant impact of critical coupling parameters on frequency is studied using graphical demonstration. Piezoelectromagnetic materials are used in a wide range of applications to constitute transducers such as actuators and sensors. Gaining insight into their wave and vibrational properties is indispensable for the advancement of reliable and optimised devices.
{"title":"A peridynamic approach to analysis of coupled magneto-electro-mechanical systems","authors":"Anasuyakumari Maram, Subrata Mondal, Sudarshan Dhua","doi":"10.1016/j.ijengsci.2025.104391","DOIUrl":"10.1016/j.ijengsci.2025.104391","url":null,"abstract":"<div><div>A non-ordinary state-based peridynamic model(NOSBPD) is presented for linear piezoelectromagnetic material(PEM). The corresponding material model is developed by establishing the connection between the classical theory of piezoelectromagnetics and the newly proposed peridynamic framework. The variational approach and Hamiltonian principle are utilised to establish the equation of motion. This investigation shows the effectiveness of the proposed model to handle piezoelectromagnetic material. It is also shown that the considered stabilisation method effectively reduces the instabilities of NOSBPD. The dynamic behaviour of piezoelectromagnetic material in the proposed framework is investigated. The dispersion relations for stabilised versions of NOSBPD in one and two dimensions are established analytically for PEM. The graphs illustrate the influence of <span><math><mi>δ</mi></math></span> and different nonlocality functions on frequency, phase velocity, and group velocity. Also, the significant impact of critical coupling parameters on frequency is studied using graphical demonstration. Piezoelectromagnetic materials are used in a wide range of applications to constitute transducers such as actuators and sensors. Gaining insight into their wave and vibrational properties is indispensable for the advancement of reliable and optimised devices.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104391"},"PeriodicalIF":5.7,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145182900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-27DOI: 10.1016/j.ijengsci.2025.104390
Vivek Kumar Singh, Krishnendu Haldar
Hydrogels are cross-linked polymeric materials capable of undergoing large deformation in response to external stimuli, such as chemical gradients and mechanical loading. This article presents a coupled chemo-mechanical model of hydrogel undergoing substantial swelling. A multiplicative decomposition-based framework is adopted to represent simultaneous swelling and mechanical deformation in a consistent thermodynamic way. A nonlinear modified hyperelastic Yeoh–Fleming model is considered for the fully swollen hydrogel to describe the strain energy of the polymer network and is calibrated from the available experiments. After calibrating the model using uniaxial stretching for different volume fractions of the polymer network, the model is then benchmarked with equi-biaxial and pure shear responses. The model calibration at different polymer network volume fractions also allows evolution of the Yeoh–Fleming model parameters with polymer network concentration. Finally, we combine the free energy of mixing of solvent and polymer network and the strain energy of polymer network to solve a coupled boundary value problem (BVP) of free swelling. The solution predicts free swelling of hydrogel and the evolution of residual stresses induced by a slow diffusion phenomenon. The numerical results presented here may provide guidance for significant applications of hydrogels in soft robotics, drug delivery and biomedical systems.
{"title":"Coupled chemo-mechanical constitutive equations and residual stress evolution of swelling hydrogels","authors":"Vivek Kumar Singh, Krishnendu Haldar","doi":"10.1016/j.ijengsci.2025.104390","DOIUrl":"10.1016/j.ijengsci.2025.104390","url":null,"abstract":"<div><div>Hydrogels are cross-linked polymeric materials capable of undergoing large deformation in response to external stimuli, such as chemical gradients and mechanical loading. This article presents a coupled chemo-mechanical model of hydrogel undergoing substantial swelling. A multiplicative decomposition-based framework is adopted to represent simultaneous swelling and mechanical deformation in a consistent thermodynamic way. A nonlinear modified hyperelastic Yeoh–Fleming model is considered for the fully swollen hydrogel to describe the strain energy of the polymer network and is calibrated from the available experiments. After calibrating the model using uniaxial stretching for different volume fractions of the polymer network, the model is then benchmarked with equi-biaxial and pure shear responses. The model calibration at different polymer network volume fractions also allows evolution of the Yeoh–Fleming model parameters with polymer network concentration. Finally, we combine the free energy of mixing of solvent and polymer network and the strain energy of polymer network to solve a coupled boundary value problem (BVP) of free swelling. The solution predicts free swelling of hydrogel and the evolution of residual stresses induced by a slow diffusion phenomenon. The numerical results presented here may provide guidance for significant applications of hydrogels in soft robotics, drug delivery and biomedical systems.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104390"},"PeriodicalIF":5.7,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145154692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-23DOI: 10.1016/j.ijengsci.2025.104388
Mohammad Daud, Jongmin Shim
We present an analytical and design framework for achieving efficient elastic wave mode conversion across meta-interfaces governed by Generalized Snell’s Law (GSL), which prescribes wave motion based on a spatial phase gradient along the interface. In contrast to conventional optimization-based approaches, our method provides clear physical insight into the mechanism of pressure-to-shear wave conversion through a simplified one-dimensional axial wave model with the transfer matrix approach. This model yields analytical expressions for geometric conditions and identifies the relevant design parameter space. Based on this framework, we propose a compact chiral-pattern subunit with a frequency-scalable geometry, enabling straightforward implementation across a range of wave conditions. Full-scale numerical simulations confirm that the resulting meta-interface achieves strong mode conversion performance and accurately reproduces key phenomena including transmitted angles. Additionally, we demonstrate symmetric transmission by introducing mirrored phase gradients, further validating the flexibility of the GSL-based design. While the conversion efficiency is constrained by angular limits inherent to the material’s Poisson ratio, the framework provides a foundation for future improvements. This work bridges analytical modeling and practical design, offering an interpretable and scalable approach to engineered wave manipulation.
{"title":"Analytical study to control phase gradient in elastic meta-interface for wave mode conversions","authors":"Mohammad Daud, Jongmin Shim","doi":"10.1016/j.ijengsci.2025.104388","DOIUrl":"10.1016/j.ijengsci.2025.104388","url":null,"abstract":"<div><div>We present an analytical and design framework for achieving efficient elastic wave mode conversion across meta-interfaces governed by Generalized Snell’s Law (GSL), which prescribes wave motion based on a spatial phase gradient along the interface. In contrast to conventional optimization-based approaches, our method provides clear physical insight into the mechanism of pressure-to-shear wave conversion through a simplified one-dimensional axial wave model with the transfer matrix approach. This model yields analytical expressions for geometric conditions and identifies the relevant design parameter space. Based on this framework, we propose a compact chiral-pattern subunit with a frequency-scalable geometry, enabling straightforward implementation across a range of wave conditions. Full-scale numerical simulations confirm that the resulting meta-interface achieves strong mode conversion performance and accurately reproduces key phenomena including transmitted angles. Additionally, we demonstrate symmetric transmission by introducing mirrored phase gradients, further validating the flexibility of the GSL-based design. While the conversion efficiency is constrained by angular limits inherent to the material’s Poisson ratio, the framework provides a foundation for future improvements. This work bridges analytical modeling and practical design, offering an interpretable and scalable approach to engineered wave manipulation.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104388"},"PeriodicalIF":5.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145117687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-22DOI: 10.1016/j.ijengsci.2025.104385
Sumanta Shagolshem , Dia Zeidan , K.V. Nagaraja
The present study provides a comprehensive symmetry analysis for a simplified two-phase flow model with the logarithmic equation of state. Under a one-parameter Lie group of transformations, we generate the local symmetry of the model, preserving the invariance of the system. Subsequently, we classify one-dimensional optimal subalgebras, which is a systematic framework for computing invariant solutions efficiently. With the characteristic method, we developed explicit solutions for the model utilizing the optimal subalgebras. Further, we prove that nonlocal symmetries exist for the considered model, and then some new exact solutions were developed where local symmetries cannot provide. Furthermore, the existence of the nonlinear self-adjointness property of the model is demonstrated with the construction of conservation laws. This study concludes by examining the complex hyperbolic nature, such as -wave, characteristic shock, and their interaction with one of the solutions derived from nonlocal symmetry, highlighting the critical wave dynamics of the model.
{"title":"Wave dynamics in the drift-flux two-phase flow model","authors":"Sumanta Shagolshem , Dia Zeidan , K.V. Nagaraja","doi":"10.1016/j.ijengsci.2025.104385","DOIUrl":"10.1016/j.ijengsci.2025.104385","url":null,"abstract":"<div><div>The present study provides a comprehensive symmetry analysis for a simplified two-phase flow model with the logarithmic equation of state. Under a one-parameter Lie group of transformations, we generate the local symmetry of the model, preserving the invariance of the system. Subsequently, we classify one-dimensional optimal subalgebras, which is a systematic framework for computing invariant solutions efficiently. With the characteristic method, we developed explicit solutions for the model utilizing the optimal subalgebras. Further, we prove that nonlocal symmetries exist for the considered model, and then some new exact solutions were developed where local symmetries cannot provide. Furthermore, the existence of the nonlinear self-adjointness property of the model is demonstrated with the construction of conservation laws. This study concludes by examining the complex hyperbolic nature, such as <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span>-wave, characteristic shock, and their interaction with one of the solutions derived from nonlocal symmetry, highlighting the critical wave dynamics of the model.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104385"},"PeriodicalIF":5.7,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145117688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-22DOI: 10.1016/j.ijengsci.2025.104389
Xianlu Liao , Yongxin Yuan
The greatest challenge for updating finite element models is to preserve the physical connectivity of the original model while ensuring that the updating is of no spill-over. In this paper, we will construct an iterative method to update mass and stiffness matrices simultaneously by utilizing modal test data and the linear projection operator , where is the linear subspace of consisting of all sparse band matrices. After finite iteration steps, we obtain the updated model which can exactly reproduce the measured data. The method can preserve both no spill-over and symmetric band structure of the mass and stiffness matrices. Three numerical examples illustrate that the proposed method is accurate and efficient.
{"title":"Symmetric band structure preserving finite element model updating problem for undamped structural systems with no spill-over","authors":"Xianlu Liao , Yongxin Yuan","doi":"10.1016/j.ijengsci.2025.104389","DOIUrl":"10.1016/j.ijengsci.2025.104389","url":null,"abstract":"<div><div>The greatest challenge for updating finite element models is to preserve the physical connectivity of the original model while ensuring that the updating is of no spill-over. In this paper, we will construct an iterative method to update mass and stiffness matrices simultaneously by utilizing modal test data and the linear projection operator <span><math><msub><mrow><mi>F</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span>, where <span><math><mi>L</mi></math></span> is the linear subspace of <span><math><msup><mrow><mi>SR</mi></mrow><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></msup></math></span> consisting of all <span><math><mrow><mi>n</mi><mo>×</mo><mi>n</mi></mrow></math></span> sparse band matrices. After finite iteration steps, we obtain the updated model which can exactly reproduce the measured data. The method can preserve both no spill-over and symmetric band structure of the mass and stiffness matrices. Three numerical examples illustrate that the proposed method is accurate and efficient.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104389"},"PeriodicalIF":5.7,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145103278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-21DOI: 10.1016/j.ijengsci.2025.104387
Arava R. Korakh, Lior Medina
The study presents a rigorous global stability analysis of a weakly coupled and electrostatically actuated double micro-beam structure. The analysis is conducted using a reduced-order (RO) model, from which an eigenvalue analysis is carried, to determine stable and unstable points along a given equilibrium curve, thus providing stable and unstable branches, that are differentiated by limit points. Under such an analysis, it is found that unlike classical structures, limit points will not necesserally coincide with extremum points in a given curve. In the current study, the analysis is extended to a range of parameters to create a global stability analysis, prompting global limit points maps, used to determine their evolution, as well as determine various stability thrsholds. The study is carried out in two stages. First, it is studied when the structure is mechanically loaded, solidifying the analysis paradigm while also serving as a preliminary validation tool, where a finite element (FE) model serves as the reference. The analysis then moves to study the effect of electrostatic load, where direct solutions of finite differences (FD) were used as the reference, after establishing their merit at the previous stage. It is shown that while a double micro-beam can become bistable when mechanically loaded, it will transform under electrostatic load to include hitherto unknown complex limit point maps, prompting tri-, quad- and quintstability, alongside new dynamic configurations, as well as unorthodox branch formations. It is shown that the model can project stability shifts of the structure and be used as a design tool for compact tristable actuators.
{"title":"Global limit points behaviour and multistable thresholds in electrostatically actuated double micro-beam structures","authors":"Arava R. Korakh, Lior Medina","doi":"10.1016/j.ijengsci.2025.104387","DOIUrl":"10.1016/j.ijengsci.2025.104387","url":null,"abstract":"<div><div>The study presents a rigorous global stability analysis of a weakly coupled and electrostatically actuated double micro-beam structure. The analysis is conducted using a reduced-order (RO) model, from which an eigenvalue analysis is carried, to determine stable and unstable points along a given equilibrium curve, thus providing stable and unstable branches, that are differentiated by limit points. Under such an analysis, it is found that unlike classical structures, limit points will not necesserally coincide with extremum points in a given curve. In the current study, the analysis is extended to a range of parameters to create a global stability analysis, prompting global limit points maps, used to determine their evolution, as well as determine various stability thrsholds. The study is carried out in two stages. First, it is studied when the structure is mechanically loaded, solidifying the analysis paradigm while also serving as a preliminary validation tool, where a finite element (FE) model serves as the reference. The analysis then moves to study the effect of electrostatic load, where direct solutions of finite differences (FD) were used as the reference, after establishing their merit at the previous stage. It is shown that while a double micro-beam can become bistable when mechanically loaded, it will transform under electrostatic load to include hitherto unknown complex limit point maps, prompting tri-, quad- and quintstability, alongside new dynamic configurations, as well as unorthodox branch formations. It is shown that the model can project stability shifts of the structure and be used as a design tool for compact tristable actuators.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104387"},"PeriodicalIF":5.7,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-19DOI: 10.1016/j.ijengsci.2025.104382
Markus Kaczvinszki, Wei Wu
We consider weak singular surfaces in the sense of Hadamard and Thomas. The jump condition for the velocity gradient across such singular surfaces is well established and often used in the bifurcation analysis of localized deformation. In this paper, we present the jump conditions for the Rivlin–Ericksen tensors for the first time. With regards to a material motion, the jump conditions are derived for both propagating and standing singular surfaces. We showcase the geometric structure of strain acceleration discontinuities and the additional restrictions posed by incompressibility. It turns out, for standing (i.e. material) discontinuities the jumps of all higher-order Rivlin–Ericksen tensors depend nonlinearly on the jump of the velocity gradient. This enables a simple setting for the description of discontinuities in certain non-Newtonian constitutive models.
{"title":"Hadamard compatibility conditions for Rivlin–Ericksen tensors on weak singular surfaces","authors":"Markus Kaczvinszki, Wei Wu","doi":"10.1016/j.ijengsci.2025.104382","DOIUrl":"10.1016/j.ijengsci.2025.104382","url":null,"abstract":"<div><div>We consider weak singular surfaces in the sense of Hadamard and Thomas. The jump condition for the velocity gradient across such singular surfaces is well established and often used in the bifurcation analysis of localized deformation. In this paper, we present the jump conditions for the Rivlin–Ericksen tensors for the first time. With regards to a material motion, the jump conditions are derived for both propagating and standing singular surfaces. We showcase the geometric structure of strain acceleration discontinuities and the additional restrictions posed by incompressibility. It turns out, for standing (i.e. material) discontinuities the jumps of all higher-order Rivlin–Ericksen tensors depend nonlinearly on the jump of the velocity gradient. This enables a simple setting for the description of discontinuities in certain non-Newtonian constitutive models.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104382"},"PeriodicalIF":5.7,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2025-09-19DOI: 10.1016/j.ijengsci.2025.104381
Steven Yang , Michal Levin , Govinda Anantha Padmanabha , Miriam Borshevsky , Ohad Cohen , D. Thomas Seidl , Reese E. Jones , Nikolaos Bouklas , Noy Cohen
Multi-material 3D printing, particularly through polymer jetting, enables the fabrication of digital materials by mixing distinct photopolymers at the micron scale within a single build to create a composite with tunable mechanical properties. This work presents an integrated experimental and computational investigation into the composition-dependent mechanical behavior of 3D printed digital materials. We experimentally characterize five formulations, combining soft and rigid UV-cured polymers under uniaxial tension and torsion across three strain and twist rates. The results reveal nonlinear and rate-dependent responses that strongly depend on composition. To model this behavior, we develop a physics-augmented neural network (PANN) that combines a partially input convex neural network (pICNN) for learning the composition-dependent hyperelastic strain energy function with a quasi-linear viscoelastic (QLV) formulation for time-dependent response. The pICNN ensures convexity with respect to strain invariants while allowing non-convex dependence on composition. To enhance interpretability, we apply sparsification. For the time-dependent response, we introduce a multilayer perceptron (MLP) to predict viscoelastic relaxation parameters from composition. The proposed model accurately captures the nonlinear, rate-dependent behavior of 3D printed digital materials in both uniaxial tension and torsion, achieving high predictive accuracy for interpolated material compositions. This approach provides a scalable framework for automated, composition-aware constitutive model discovery for multi-material 3D printing.
{"title":"Physics augmented machine learning discovery of composition-dependent constitutive laws for 3D printed digital materials","authors":"Steven Yang , Michal Levin , Govinda Anantha Padmanabha , Miriam Borshevsky , Ohad Cohen , D. Thomas Seidl , Reese E. Jones , Nikolaos Bouklas , Noy Cohen","doi":"10.1016/j.ijengsci.2025.104381","DOIUrl":"10.1016/j.ijengsci.2025.104381","url":null,"abstract":"<div><div>Multi-material 3D printing, particularly through polymer jetting, enables the fabrication of digital materials by mixing distinct photopolymers at the micron scale within a single build to create a composite with tunable mechanical properties. This work presents an integrated experimental and computational investigation into the composition-dependent mechanical behavior of 3D printed digital materials. We experimentally characterize five formulations, combining soft and rigid UV-cured polymers under uniaxial tension and torsion across three strain and twist rates. The results reveal nonlinear and rate-dependent responses that strongly depend on composition. To model this behavior, we develop a physics-augmented neural network (PANN) that combines a partially input convex neural network (pICNN) for learning the composition-dependent hyperelastic strain energy function with a quasi-linear viscoelastic (QLV) formulation for time-dependent response. The pICNN ensures convexity with respect to strain invariants while allowing non-convex dependence on composition. To enhance interpretability, we apply <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> sparsification. For the time-dependent response, we introduce a multilayer perceptron (MLP) to predict viscoelastic relaxation parameters from composition. The proposed model accurately captures the nonlinear, rate-dependent behavior of 3D printed digital materials in both uniaxial tension and torsion, achieving high predictive accuracy for interpolated material compositions. This approach provides a scalable framework for automated, composition-aware constitutive model discovery for multi-material 3D printing.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104381"},"PeriodicalIF":5.7,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In structural engineering, accurate modeling of material damage is crucial, particularly the tension–compression asymmetry observed in quasi-brittle materials and adhesive joints. While cohesive interface models are commonly employed in the analysis of bonded structures, the parameters of these models frequently lack a direct correlation with the physical properties of the adhesive layer. To address this issue and capture the tension–compression asymmetry, this study uses asymptotic analysis to derive two new interface damage models (termed F1d and F2d) from a thin damaging interphase. The proposed models are formulated within a thermodynamically consistent framework. The F1d model uses a single damage variable with an asymmetric evolution law, whereas the more advanced F2d model uses separate variables for tensile and compressive damage, enabling independent evolution kinetics. To bridge the gap between scales and link macroscopic damage to micro-defect evolution, the new models are coupled with two micromechanical schemes: the non-interacting Kachanov–Sevostianov model and the Mori–Tanaka–Benveniste model, the latter of which accounts for defect interactions. The theoretical formulations of the models are presented, and their predictive capabilities are demonstrated through numerical simulations of a bonded joint under axial loading.
{"title":"Predictive asymptotic models of damage evolution in thin adhesives with tension–compression asymmetry","authors":"Michele Serpilli , Raffaella Rizzoni , Frédéric Lebon","doi":"10.1016/j.ijengsci.2025.104384","DOIUrl":"10.1016/j.ijengsci.2025.104384","url":null,"abstract":"<div><div>In structural engineering, accurate modeling of material damage is crucial, particularly the tension–compression asymmetry observed in quasi-brittle materials and adhesive joints. While cohesive interface models are commonly employed in the analysis of bonded structures, the parameters of these models frequently lack a direct correlation with the physical properties of the adhesive layer. To address this issue and capture the tension–compression asymmetry, this study uses asymptotic analysis to derive two new interface damage models (termed F1d and F2d) from a thin damaging interphase. The proposed models are formulated within a thermodynamically consistent framework. The F1d model uses a single damage variable with an asymmetric evolution law, whereas the more advanced F2d model uses separate variables for tensile and compressive damage, enabling independent evolution kinetics. To bridge the gap between scales and link macroscopic damage to micro-defect evolution, the new models are coupled with two micromechanical schemes: the non-interacting Kachanov–Sevostianov model and the Mori–Tanaka–Benveniste model, the latter of which accounts for defect interactions. The theoretical formulations of the models are presented, and their predictive capabilities are demonstrated through numerical simulations of a bonded joint under axial loading.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"217 ","pages":"Article 104384"},"PeriodicalIF":5.7,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145095238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号