Gerfried Millner , Gabriel Kronberger , Manfred Mücke , Lorenz Romaner , Daniel Scheiber
{"title":"Comparison of semi-empirical models, symbolic regression, and machine learning approaches for prediction of tensile strength in steels","authors":"Gerfried Millner , Gabriel Kronberger , Manfred Mücke , Lorenz Romaner , Daniel Scheiber","doi":"10.1016/j.ijengsci.2025.104247","DOIUrl":"10.1016/j.ijengsci.2025.104247","url":null,"abstract":"<div><div>We employ data-driven models to predict the tensile strength of steel coils using information on their chemical composition and process parameters. The dataset contains extensive chemical analyses, diverse process parameters, and the characterized tensile strength as target property. We compare prediction quality and traceability of the predictions of pure machine learning models and physics-informed models. To introduce physical knowledge, we combine models from literature knowledge with symbolic regression and compare the physics-inspired models to machine learning models. In contrast to classic black-box models, symbolic regression provides mathematical equations for the estimation of the target value, facilitating straightforward interpretation. To analyze the predictions from classic black-box machine learning models, we use feature importance analysis with SHAP and contrast the obtained feature impacts with physics-based model parameters. We find that for the present use case, Artificial Neural Networks perform best, while the physics-infused models from symbolic regression allow for better interpretability.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"212 ","pages":"Article 104247"},"PeriodicalIF":5.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737960","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}
{"title":"Indentation of layered soft electroactive media","authors":"Guozhan Xia , Zhiqing Zhang , Ernian Pan","doi":"10.1016/j.ijengsci.2025.104250","DOIUrl":"10.1016/j.ijengsci.2025.104250","url":null,"abstract":"<div><div>Novel layered soft electroactive materials/structures have various special functions and features which can be uniquely applied to different modern science and engineering fields. In this paper, three-dimensional full-field solutions for the indentation characterization of layered soft electroactive media are presented by using a newly established semi-analytical approach. This approach is based on the integration of the Fourier-Bessel series system of vector functions, the dual-variable and position method and the Green's function. For illustration, the flat-ended indentation of a layered neo-Hookean ideal dielectric half-space, incorporating interfacial imperfections and material inhomogeneity between adjacent layers, is taken as an example. The present method is first verified by comparing with the exact solution for a reduced homogeneous case and then applied to multi-layered half-spaces with varying interfacial conditions, ranging from the frictionless contact case to the perfectly bonded case, and with linearly/exponentially graded shear moduli within the layers. The effects of the material compressibility and the interfacial imperfections on the full-field responses are investigated through one-layer and two-layer half-space models, respectively. The imperfections are found to play as barriers in the propagation of indentation-induced distortion within the layered structure. The comparison between the incremental von Mises stress for 20-layer and 100-layer half-spaces further highlights the positive significance of increasing layers to prevent stress mismatches in such structures. Most interestingly, with the advantage of much lower cost on fabrication, the layered structure with sufficient layers is quantitively demonstrated to achieve desired performance comparable to the continuously graded one. We believe that the present study not only establishes a good reference for characterizing the properties of soft multi-field coupled materials/structures containing material inhomogeneity and/or imperfections but also provides a benchmark pattern for addressing related complex boundary-value problems.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104250"},"PeriodicalIF":5.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725723","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}
Feng Zhu , Zhenghua Qian , Peng Li , Iren Kuznetsova , Zhao Yang
{"title":"A novel theoretical and computational framework to quantify dielectric relaxation effects on lamb waves in piezocomposites","authors":"Feng Zhu , Zhenghua Qian , Peng Li , Iren Kuznetsova , Zhao Yang","doi":"10.1016/j.ijengsci.2025.104260","DOIUrl":"10.1016/j.ijengsci.2025.104260","url":null,"abstract":"<div><div>Dielectric relaxation is a widespread physical phenomenon that results in the dielectric coefficient taking on complex values, with both the real and imaginary parts changing in response to variations in frequency and temperature. It is evident that dielectric relaxation affects the dynamic performance of piezoelectric acoustic devices. However, research on this topic remains limited. In this paper, a theoretical framework based on the Debye/Cole-Cole models and continuum mechanics is developed to investigate the effect of dielectric relaxation on wave motion in piezocomposites. This framework describes the wave phase velocity changes and attenuation characteristics caused by dielectric relaxation across multiple scales and at varying temperatures. To quantify the impact, an accurate calculation is performed using a novel numerical method called Multidimensional Moduli Ratio Convergence (MMRC), which features a new root-discriminating mechanism and employs a two-dimensional (2D) root-finding approach to ensure efficient and robust solutions. A three-dimensional (3D) complex dispersion curve is obtained, revealing the propagation and attenuation characteristics of the wave. Six different wave mode shapes (Bending, Tensile, Thickness Tensile, and the first, second, and third Thickness Shear) in symmetric and antisymmetric modes are identified, and their attenuation effects are determined. Further investigation reveals the impact of frequency and temperature variations on the phase velocity and attenuation of the wave. This work is crucial for improving the performance of piezoelectric devices, particularly in terms of attenuation and frequency drift control.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104260"},"PeriodicalIF":5.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703973","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}
{"title":"Experiments on the finite torsion of nearly incompressible rubber-like materials: Nonlinear effects, analytic modeling and rubber characterization","authors":"Federico Oyedeji Falope, Luca Lanzoni, Angelo Marcello Tarantino","doi":"10.1016/j.ijengsci.2025.104254","DOIUrl":"10.1016/j.ijengsci.2025.104254","url":null,"abstract":"<div><div>We present experiments and analytic modeling of different states of finite torsion of soft cylinders. The problems of <em>free torsion</em> and <em>restrained torsion</em> are investigated. In free torsion, the cylinder is twisted and left free to elongate, thus exhibiting the <em>Poynting elongation</em>. In restrained torsion, the elongation of the cylinder is inhibited, so a reactive axial force arises (<em>Poynting force</em>). The nonlinear Poynting effects, elongation and force, are observed and quantified with a specifically designed device able to simulate both cases of torsion. Punctual laser devices, digital image correlation monitoring, and load cells are used to measure the contraction of the cylinder diameter, Poynting elongation, Poynting force, and twisting moment. The experiments are performed on three rubber-like materials: a silicone rubber and two polyurethanes. Uniaxial tension and compression have been performed along with the torsion tests. The tests show that the investigated materials are nearly incompressible, allowing to model the restrained torsion tests with the theory of <em>simple torsion</em> of incompressible materials. The results of restrained torsion tests reveal that a <em>universal relation</em> established for incompressible materials independent of the second invariant of deformation is violated. Hence, the material characterization is carried out for energy laws of the form <span><math><mrow><mi>W</mi><mrow><mo>(</mo><msub><mrow><mi>I</mi></mrow><mrow><mn>1</mn></mrow></msub><mo>,</mo><msub><mrow><mi>I</mi></mrow><mrow><mn>2</mn></mrow></msub><mo>)</mo></mrow></mrow></math></span> and a compressible Mooney–Rivlin law. The experimental behavior of the universal relation indicates that the energy dependence on the second invariant of deformation decreases as the deformation increases. We show that simultaneous fitting of uniaxial and torsion tests relevantly reduces the quality of the best-fit procedure. The present work points out the importance of the compressibility of the material for an accurate prediction of the Poynting elongation, which is not grasped well by the incompressible laws.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104254"},"PeriodicalIF":5.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sayed Mohamad Mirfatah , Hamzeh Salehipour , Ömer Civalek
{"title":"On the nonlinear forced vibration of nanoshells via nonlocal strain gradient theory","authors":"Sayed Mohamad Mirfatah , Hamzeh Salehipour , Ömer Civalek","doi":"10.1016/j.ijengsci.2025.104257","DOIUrl":"10.1016/j.ijengsci.2025.104257","url":null,"abstract":"<div><div>This paper investigates the nonlinear forced vibration of doubly curved sandwich nanoshells with auxetic honeycomb core having negative Poisson's ratio and nanocomposite-reinforced coatings. It is assumed that the nanoshell structure rests on Winkler-Pasternak foundation. The dynamic response is analyzed under various periodic and impulsive pressure excitations. The basic governing, compatibility, and constitutive equations are derived in the context of the non-classical nonlocal strain gradient elasticity theory to rigorously account for the size-dependent effects in nonlinear dynamic response at nanoscale. Utilizing the first-order shear deformation theory, representing the strain components in terms of the deformation field and its derivatives, the derived governing equations can be expressed in a system of three-dimensional nonlinear partial differential equations. To achieve a closed-form solution avoiding the complexities of the numerical iterative methods in presence of geometrical nonlinearities, the considered shallow nanoshell panels are taken as simply supported at their different fixed or moveable states. Further, assuming an appropriate approximation for the deformation field, utilizing the Galerkin method, the governing partial differential equations are reduced to an explicit formulation of the corresponding ordinary differential equation of motion which is numerically solved by the Runge-Kutta (RK) method. In numerical investigations, the accuracy and reliability of the proposed analytical-numerical approach are first validated by comparing the obtained results with benchmark solutions available in the literature. Subsequently, the influence of various parameters, including mechanical and geometrical properties, boundary conditions, and different periodic and impulsive external pressure excitations, on the geometrically nonlinear forced vibration behavior of the nanoshell panels is systematically analyzed using the developed solution methodology.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104257"},"PeriodicalIF":5.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703974","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}
Jean-François Ganghoffer , Xuan-Nam Do , Ibrahim Goda
{"title":"Dynamical homogenization of microstructured media towards micromorphic effective continua","authors":"Jean-François Ganghoffer , Xuan-Nam Do , Ibrahim Goda","doi":"10.1016/j.ijengsci.2025.104255","DOIUrl":"10.1016/j.ijengsci.2025.104255","url":null,"abstract":"<div><div>The virtual power principle for materials with microstructure modeled in the framework of micromorphic effective media is written from a micromechanical perspective, considering recent contributions of (Alavi et al., 2021, 2023) however restricting to statics. In the present work, we extend the micromorphic framework to dynamics by deriving the macroscopic kinetic energy from the upscaling of microscopic classical principles. Our methodology focuses on identifying a homogeneous velocity that captures the microscale kinematics of the micromorphic effective medium, defined by the macroscopic velocity and the rates of the displacement gradient, distortion tensor, and its first gradient. Unit cell boundary value problems are formulated for the velocity fluctuation that leads to the computation of the effective dynamical micromorphic properties. The predictions of kinetic energy, incorporating higher-order contributions, are exemplified by the square and tetrachiral unit cells, emphasizing the crucial role of structural design in micromorphic media. Internal length scales, comparable to the unit cell size, further validate the micromorphic model's capability to capture scale-dependent effects and demonstrate its effectiveness in predicting the dynamic behavior of architected materials.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104255"},"PeriodicalIF":5.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703972","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}
{"title":"Effective elastic stiffness of polycrystalline solid with general imperfect interface","authors":"Volodymyr I. Kushch","doi":"10.1016/j.ijengsci.2025.104259","DOIUrl":"10.1016/j.ijengsci.2025.104259","url":null,"abstract":"<div><div>The analytical self-consistent model of a polycrystalline solid with isotropic grains and a general imperfect interface has been developed. The grain-to-grain bonding conditions assume a jump of both the displacement and normal traction vectors across the interface. The model is consistent with the general theory of curved deformable interfaces in solids with nanometre-scale microstructure (Gurtin et al., 1998) that justifies its applicability to the elastic nanopolycrystals. The proper formulation of the self-consistent micromechanical model of polycrystal imperfect interface is discussed. The explicit formulas for the effective elastic moduli are derived from the multipole expansion solution to the model problem under the zero dipole moment condition of the imperfectly bonded inhomogeneity in the effective medium. The developed theory and numerical results are validated by comparison with the available results for the spring and membrane-type interfaces.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104259"},"PeriodicalIF":5.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696756","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}
{"title":"A phantom-chain based viscoplastic model for local relaxation of magneto-active polymer composites under dynamic magnetic field","authors":"Li Zhang , Ran Tao , Yiqi Mao , Shujuan Hou","doi":"10.1016/j.ijengsci.2025.104252","DOIUrl":"10.1016/j.ijengsci.2025.104252","url":null,"abstract":"<div><div>Magneto-active polymer composites (MAPCs) can change their mechanical properties (i.e., stiffness) and/or mechanical deformation upon an external magnetic stimulus. The mechanical response of MAPCs is primarily determined by the interaction between the polymer matrix and magnetic particles, alongside the performance of the constituent materials. When a directional dynamic magnetic field is applied, mainly two types of relaxation behavior occur due to magnetic particle oscillations and rotations, i.e., heat-generation caused phase change and viscosity reduction, and chain cleavage and de-adhesion from particles. This material relaxation caused by local chain debonding is fundamentally different from that by the phase transition characterized with variation of free volumes. This work proposes a phantom-chain based magnetomechanical model to reflect magnetic particles oscillating caused local material relaxation, and a Maxwell rheological model is superimposed to capture the heat-triggered relaxation behavior of MAPCs under dynamic magnetic field. Considering changes in the chain configuration, a phantom-chain model is constructed by wave-propagation modeling and further integrated through full network space to capture the overall magnetomechanical properties of MAPCs. The magnetic field triggered heat-generation is simulated by both Brownian relaxation and Neel relaxation. The model is calibrated through a series of tests and then applied in simulations of the isothermal uniaxial tension of MAPCs, both with and without external magnetic fields. These simulations show the model's effectiveness in capturing the material relaxation behavior of MAPCs under dynamic magnetic activation. Good agreement between the simulations and experiments demonstrates the validation and effectiveness of the proposed model and solution procedure. The calibrated model is further applied to the multi-cycle shape memory modeling of MAPCs under the alternating magnetic field. This work lays a theoretical foundation and contributes to the design and widespread application of 3D complex microstructured MAPCs.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104252"},"PeriodicalIF":5.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681377","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}
{"title":"Elastic waves in graphene origami-enabled auxetic metamaterial thickness-deformable doubly-curved shells","authors":"Behrouz Karami, Mergen H. Ghayesh","doi":"10.1016/j.ijengsci.2025.104249","DOIUrl":"10.1016/j.ijengsci.2025.104249","url":null,"abstract":"<div><div>This study, for the first time, investigates the bulk waves in mechanical metamaterial thickness- and shear-deformable doubly-curved shells; it considers spherical, elliptical, hyperbolic, and cylindrical shell structures. A third-order shear deformable model, involving thickness deformation, is employed to capture in-surface and out-of-surface, rotational, and stretching motions within a curvilinear coordinate system. Equations of motion are obtained via Hamilton’s principle, resulting in a set of coupled partial differential equations. A genetic programming-based micromechanics method for mechanical properties has been developed in the literature recently; this paper uses it as simulation inputs. A harmonic approach is used to solve these equations and to obtain the circular frequency. For the spherical, elliptical, hyperbolic, and cylindrical shells, influences of the curvatures on the wave frequency are highlighted. In the Appendix, a comparative analysis for a simplified case (excluding metamaterial effects, and multilayer configurations) demonstrates very good agreement with prior studies.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104249"},"PeriodicalIF":5.7,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678392","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}
{"title":"Surface-oriented homogenization method for size-dependent thermal expansion coefficient of thermal metamaterial","authors":"Xiaofeng Xu, Ling Ling, Li Li","doi":"10.1016/j.ijengsci.2025.104248","DOIUrl":"10.1016/j.ijengsci.2025.104248","url":null,"abstract":"<div><div>This paper explores the influence of microstructures on the effective thermal expansion coefficient of thermal metamaterials, highlighting the surface-induced size-dependent effects. These effects stem from the unique porous microstructural characteristics, influenced by volume fraction and geometric configuration. Unlike nanoscale phonon-driven surface effects, comprehensive finite element numerical simulations reveal that macroscopic surface mechanisms in thermal metamaterials arise from changes in heat conduction pathways due to microstructural features. These surface regions, characterized by an intrinsic length, are determined by the microstructure itself. To accurately capture the complex size-dependent coefficients of linear thermal expansion, we developed a surface-oriented homogenization method that leverages the interaction between extrinsic and intrinsic length under surface mechanisms. Unlike classical homogenization methods, this approach does not require compliance with the principle of scale separation. The effectiveness of this surface-oriented homogenization method is demonstrated through simulations of thermal metamaterial sheet subjected to temperature variations, highlighting that this method combines the efficiency of traditional homogenization methods with the high accuracy of high-fidelity finite element methods. This paper not only provides a novel surface-oriented homogenization approach that can overcome computational challenges of thermal metamaterial structures but also offers an approach to constructing an offline dataset for the intrinsic length that is beneficial to guiding the data-driven design of thermal metamaterial structures.</div></div>","PeriodicalId":14053,"journal":{"name":"International Journal of Engineering Science","volume":"211 ","pages":"Article 104248"},"PeriodicalIF":5.7,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143678393","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}