Mechanics of Materials最新文献

{"title":"Influence of experimental data set choice for constitutive parameters identification for machining simulations","authors":"Adam Najem,&nbsp;Guillaume Altmeyer,&nbsp;Louis Esnault,&nbsp;Arnaud Duchosal","doi":"10.1016/j.mechmat.2025.105516","DOIUrl":"10.1016/j.mechmat.2025.105516","url":null,"abstract":"<div><div>This work focuses on the characterization of the X100CrMoV5 steel alloy and the identification of its constitutive parameters for machining simulations using shear tests. Experimental tests were conducted on a thermo-mechanical Gleeble machine under dynamic conditions, at ambient and elevated temperatures. A numerical model was developed to simulate the shear test, enabling a comprehensive comparison with the experimental data. Both experimental and numerical data were de-noised using the Singular Value Decomposition (SVD) method, effectively removing experimental noise and numerical instabilities. The Levenberg–Marquardt identification algorithm based on gradient descent was then employed to minimize the error between numerical and experimental results, facilitating the simultaneous identification of all parameters of the material behavior model. This behavior model included an elastic phase, described by Hooke’s Law, followed by a thermo-visco-plastic phase, modeled using the Johnson–Cook law. The Johnson–Cook damage criterion was applied to determine the material’s rupture point, while the Hillerborg energy criterion was used to model energy dissipation during the damage process. Additionally, the Taylor–Quinney coefficient was incorporated to model thermo-mechanical dissipation. All parameters were identified through a global identification approach, wherein they were determined simultaneously to account for their inter-dependencies using all available experimental data. The experimental data sets where used either individually or collectively influencing the identification procedure. The results of the characterization and identification of the behavior of X100CrMoV5 are presented here, highlighting the material’s response under varying conditions and the role of the identification approach used.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105516"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thermo-order-mechanical coupled model for main-chain isotropic-genesis polydomain liquid crystal elastomers","authors":"Baihong Chen ,&nbsp;Lingrui Zhu ,&nbsp;Huxiao Yang ,&nbsp;Rui Xiao","doi":"10.1016/j.mechmat.2025.105531","DOIUrl":"10.1016/j.mechmat.2025.105531","url":null,"abstract":"<div><div>Polydomain liquid crystal elastomers (LCEs) are composed of numerous micron-scale domains, each with a distinct director orientation, resulting in macroscopic isotropy. In recent years, main-chain polydomain LCEs crosslinked in the isotropic state (I-PLCEs) have obtained increasing scientific and technological interest due to their complex thermo-order-mechanical coupling behaviors, which include the polydomain–monodomain (PM) transition, energy dissipation capability and stimuli-responsive actuation. In this work, we develop a constitutive model to describe these coupled behaviors in I-PLCEs. The model incorporates internal state variables to represent mesogen orientation. The free energy consists of the elastic energy arising from the deformation of the polymer networks and a residual energy due to the incompatibilities within the microscope nematic domain. The temperature affects both the rate of mesogen orientation and the order parameter. Under quasi-static loading conditions, an energy minimization approach governs the evolution equations, enabling the prediction of the extremely small equilibrium threshold stress required for the PM transition in I-PLCEs. Comparisons between model predictions and experimental data demonstrate that the model accurately reproduces the stress response of I-PLCEs at different temperatures and effectively captures the thermal actuation stretch under constant nominal stress. This work provides an efficient modeling framework for describing the coupled thermo-mechanical response of main-chain I-PLCEs.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105531"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Learning a potential formulation for rate-and-state friction","authors":"Shengduo Liu,&nbsp;Kaushik Bhattacharya,&nbsp;Nadia Lapusta","doi":"10.1016/j.mechmat.2025.105540","DOIUrl":"10.1016/j.mechmat.2025.105540","url":null,"abstract":"<div><div>Empirical rate-and-state friction laws are widely used in geophysics and engineering to simulate interface slip. They postulate that the friction coefficient depends on the local slip rate and a state variable that reflects the history of slip. Depending on the parameters, rate-and-state friction can be either rate-strengthening, leading to steady slip, or rate-weakening, leading to unsteady stick–slip behavior modeling earthquakes. Rate-and-state friction does not have a potential or variational formulation, making implicit solution approaches difficult and implementation numerically expensive. In this work, we propose a potential formulation for the rate-and-state friction. We formulate the potentials as neural operators and train them so that the resulting behavior emulates the empirical rate-and-state friction. We show that this potential formulation enables implicit time discretization leading to efficient numerical implementation.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105540"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesoscale finite element modeling of EPS bead size effect on the strength and failure of lightweight concrete","authors":"Yasin Mohammadi,&nbsp;Sharif Shahbeyk","doi":"10.1016/j.mechmat.2025.105533","DOIUrl":"10.1016/j.mechmat.2025.105533","url":null,"abstract":"<div><div>The mechanical performance of EPS concrete is strongly influenced by bead content and size, with smaller beads generally enhancing strength. This study develops a continuum mechanics framework that explicitly incorporates mortar, aggregates, and EPS beads. The mortar is modeled using a plastic-damage law, enhanced with a new compressive damage–strain relation and a strain-shifting procedure to reduce mesh sensitivity, while EPS beads are represented by an isotropic crushable foam model calibrated from experiments. A comprehensive set of meso-scale finite element analyses was conducted under both uniaxial compression and three-point bending, enabling prediction of compressive strength and modulus of rupture. The framework reproduces experimental strength–size dependencies, elucidates porosity-driven damage initiation and evolution, and introduces a new mathematical relation linking compressive strength with EPS volume ratio.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105533"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An augmented surface impedance theory for acoustically actuated magneto-electro-elastic nanospheres with terahertz nanoantenna applications","authors":"Mohsen Farsiani ,&nbsp;Hossein M. Shodja","doi":"10.1016/j.mechmat.2025.105515","DOIUrl":"10.1016/j.mechmat.2025.105515","url":null,"abstract":"<div><div>A precise analytical treatment for predicting the behavior of nano-sized magneto-electro-elastic (MEE) antennas and resonators under incident acoustic waves requires careful consideration of multiphysics surface/interface effects, including magnetization, polarization, and elasticity. To date, no analytical solutions have incorporated all three phenomena simultaneously. By addressing these surface effects, this work presents a rigorous mathematical analysis of a nano-sized spherically isotropic embedded MEE spherical shell subjected to incident acoustic waves. The set of coupled spectral constitutive relations relevant to the bulk of the MEE spherical shell is distinguished from those pertinent to its free inner surface and matrix-shell interface. The surrounding matrix may consist of an isotropic dielectric or metallic material. Conventional electrodynamics theories are insufficient to address this problem, as they do not adequately account for MEE effects at the surface or interface. To overcome this limitation, the study employs the equivalent impedance matrix (EIM) method combined with surface/interface elasticity to model the surface/interface MEE behaviors rigorously. For metallic matrices, a plasmonics-based mathematical framework is utilized, with the optical properties described by the plasma model to accurately capture metallic behavior. The spectral EIM method, combined with vector and tensor spherical harmonics forming a Schauder basis for square-integrable vector fields and second-rank symmetric tensor fields on the unit sphere, is shown to be a pivotal tool for solving the fully coupled elastodynamics and Maxwell’s equations. This approach is particularly effective in capturing significant MEE surface/interface effects. This methodology enables a detailed exploration of surface/interface characteristic lengths, facilitating the examination of size-dependent effects on electromagnetic radiated power and fundamental resonance frequency. The findings provide valuable insights into the behavior of acoustically actuated nanospherical antennas, nanosensors, and nanoresonators based on MEE nanospheres. Moreover, these results have significant implications for the design and optimization of nanoscale devices in advanced technological applications.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105515"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantification of the influence of laser shock peening parameters on residual stresses in thick AA 7050 specimens: An experimental and explainable machine learning-based approach","authors":"Claudia Barile,&nbsp;Simone Carone,&nbsp;Caterina Casavola,&nbsp;Giovanni Pappalettera","doi":"10.1016/j.mechmat.2025.105536","DOIUrl":"10.1016/j.mechmat.2025.105536","url":null,"abstract":"<div><div>Laser Shock Peening (LSP) is a mechanical treatment capable of inducing a compressive residual stress field in the surface of a component, thereby improving its fatigue behavior. However, the selection of process parameters and the component geometric factors, such as thickness, are of paramount importance in the optimization of the final residual stresses, which exhibit a complex response due to the interaction between the process variables. An explainable machine learning framework has the potential to model the LSP treatment with high accuracy, while concurrently providing interpretations on the results and the process parameters' influence and interrelation. In this study, the effect of LSP on residual stresses in thick AA 7050-T7451 was experimentally investigated using incremental hole drilling with a Gaussian Process Regression-based approach to minimize user influence. Subsequently, experimental data was used to construct a robust ensemble machine learning model, namely a Random Forest, which achieved high generalization power by utilizing a rigorous K-Folds cross-validation with 100 repetitions. Finally, a critical comparative analysis of different approaches to determine feature importance was conducted. In this context, the SHapley Additive exPlanation (SHAP) framework emerged as a significant tool, providing reliable results and interpretations at both global and local levels. In this way, a quantitative assessment of the contributions of the LSP variables for each individual residual stress measurement was achieved. This allowed a deeper understanding of the effects of these parameters and their mutual interactions.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105536"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145418204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variationally consistent microstructure evolution and microsphere-based reconvexification for damage with application to arterial tissues","authors":"Jan Melchior,&nbsp;Maximilian Köhler,&nbsp;Daniel Balzani","doi":"10.1016/j.mechmat.2025.105495","DOIUrl":"10.1016/j.mechmat.2025.105495","url":null,"abstract":"<div><div>Modeling the softening of arterial tissue, as it can be observed in terms of strain softening preceding atherosclerotic plaque rupture or in terms of stress-softening during balloon angioplasty, places special demands on the material formulations employed. In the context of finite-element discretized boundary value problems, the softening of the material is typically associated with a non-convex strain energy, which leads to an ill-posed behavior, i.e., mesh-dependency. In this work, we discuss the applicability of a material model for strain-softening that is based on the repeated construction of the convex envelope of an initially non-convex strain energy. The model possesses an evolving property that is exploited for the description of material softening. We propose an accurate and efficient convexification method, which is based on the reformulation of the convexity requirement in terms of a new optimization problem. Furthermore, we adopt the formulation to model softening in arterial tissue by combining a microsphere approach with a new orientation distribution function representing the dispersion of collagen fibers and show its capability to represent experimental data. Finally, we provide the derivation of a variationally sound approach to damage microstructure evolution and analyze some unique aspects significantly limiting the applicability to strain-softening.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105495"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrically induced local creep in dielectric polymers: Experiments and modeling","authors":"Zhigang Liu ,&nbsp;Guian Man ,&nbsp;Xuhui Fan ,&nbsp;Boyuan Huang ,&nbsp;Jiangyu Li","doi":"10.1016/j.mechmat.2025.105529","DOIUrl":"10.1016/j.mechmat.2025.105529","url":null,"abstract":"<div><div>Dielectric polymers such as biaxially oriented polypropylene (BOPP) are widely used in capacitors for electric energy storage and pulse power. Under working conditions, they are subjected to high voltage as well as cyclic charging and discharging, resulting in significant Maxwell strain that evolves due to viscoelasticity. Such creep behavior has important implications to the reliability, aging, and breakdown failure of dielectric polymers, and we seek to understand it with the goal to predict the long term strain evolution using short term experimental data. We established a digital image correlation based experimental setup to monitor field induced deformation <em>in-situ</em>, observing significant strain concentration as well as creep. We carried out systematical analysis using Burgers model and find that it is incapable of predicting long term local creep of BOPP at strain concentration, despite its success in capturing mechanical creep as well as the evolution of average strain under an electric field. We thus developed a modified Burgers model that accounts for the evolution of concentrated electric field and accurately predicted long term local creep under either constant or cyclic voltage. In particular, we successfully predicted the evolution of concentrated local strain up to 10⁶ s using the experimental data in the first 10³ s, demonstrating the power of our modified Burgers model. We expect that the modified Burgers model will play an important role in analyzing aging and failure behaviors of dielectric polymers and capacitive devices.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105529"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anisotropic plasticity and damage of additively manufactured 316L stainless steel by multiscale approach","authors":"K. Siriraksophon ,&nbsp;N. Vajragupta ,&nbsp;V. Uthaisangsuk","doi":"10.1016/j.mechmat.2025.105509","DOIUrl":"10.1016/j.mechmat.2025.105509","url":null,"abstract":"<div><div>Stainless steel 316L produced by laser powder bed fusion (L-PBF) technique exhibits distinctly patterned microstructures due to directional rapid cooling of successive layers. Thus, its tensile properties are highly anisotropic depending on applied build strategies that often led to inferior performance compared to conventional 316L steel. In this work, a multiscale modeling approach was proposed for more precisely describing effects of complex printed microstructure characteristics on local and overall deformation behaviors of the steel. Micro-scale models incorporated grain morphologies and crystallographic textures developed in different melt pools. Hereby, the strain gradient crystal plasticity (CP) model was used to thoroughly reveal anisotropic stress-strain responses which were primarily driven by crystallographic features. Subsequently, a meso-scale model was employed to elucidate the heterogeneous deformation occurring at the melt pool boundaries, particularly in relation to the specified scanning patterns. Homogenized stress-strain properties of each meso-scale region were obtained from the micro-scale models in conjunction with the Hill48 yield criterion. Furthermore, the Hosford-Coulomb ductile damage model was defined on the meso-scale for representing crack initiations at crucial sites of the melt pools. The model showed that the grain configurations of 45°/0°/45° and −90°/0°/90° in melt pools strongly governed the anisotropic strain hardening behavior of printed samples. Local stress incompatibilities induced by grain and melt pool arrangements according to the defined scanning strategies resulted in different strain localizations and following damages. The approach can further serve as a framework for 3D printed material designs requiring more accurate microstructure-properties relationships.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105509"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145271494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Disordered origins, deterministic outcomes: How the architecture of elastic networks imprints relaxed structure and mechanics","authors":"Stefanie Heyden ,&nbsp;Mohit Pundir ,&nbsp;Eric R. Dufresne ,&nbsp;David S. Kammer","doi":"10.1016/j.mechmat.2025.105538","DOIUrl":"10.1016/j.mechmat.2025.105538","url":null,"abstract":"<div><div>This work targets the influence of disorder on the relaxed structure and macroscopic mechanical properties of elastic networks. We construct network classes of different types of disorder (length, topology and stiffness), which are subsequently equilibrated in a finite kinematics setting. Relaxed network structures are distinct among network classes, which opens the path towards exploiting easily accessible experimental measures as a way of inferring further microstructural details.</div></div>","PeriodicalId":18296,"journal":{"name":"Mechanics of Materials","volume":"212 ","pages":"Article 105538"},"PeriodicalIF":4.1,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}