Finite Elements in Analysis and Design最新文献

{"title":"A physically based Proper Orthogonal Decomposition for structural mechanics involving dissipative processes","authors":"L. Cimatti Lucarelli ,&nbsp;N. Blal ,&nbsp;A. Platzer ,&nbsp;A. Gravouil ,&nbsp;D. Iampietro","doi":"10.1016/j.finel.2025.104386","DOIUrl":"10.1016/j.finel.2025.104386","url":null,"abstract":"<div><div>This paper proposes a framework for a physically based POD (Proper Orthogonal Decomposition), denoted <span><math><mi>φ</mi></math></span>POD. The proposed Reduced Order Model (ROM) is set to respect one of the evolution equations of an elasto-viscoplastic material. The <span><math><mi>φ</mi></math></span>POD is obtained through the solution of a constrained minimization problem over the reduced coordinates of the POD. Furthermore, a physically based Reduced Order Surrogate Model (ROSM) is constructed based on <em>Interpolation on a Tangent Space to the Grassmann manifold</em> (ITSGM). This paper uses the 2D Cook’s membrane under plane strain hypothesis as an application case. The performance metrics to compare the <span><math><mi>φ</mi></math></span>POD to the regular POD are the residual of the constrained equation, projection energies, and interpolation error for mechanical fields.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"250 ","pages":"Article 104386"},"PeriodicalIF":3.5,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144239800","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}

{"title":"A parallel FreeFEM framework for topology optimization of structures into three spatial dimensions","authors":"J.M.M. Luz Filho,&nbsp;A.T.A. Gomes,&nbsp;A.A. Novotny","doi":"10.1016/j.finel.2025.104384","DOIUrl":"10.1016/j.finel.2025.104384","url":null,"abstract":"<div><div>This article presents a simple and compact parallel FreeFEM implementation for topology optimization of structures into three spatial dimensions. The topology optimization algorithm relies on the topological derivative concept together with a level-set domain representation method, in which the topological derivative is used as a steepest descent direction evolving the level-set function within the optimization procedure. In addition, adaptive mesh refinement is performed in the optimization scheme for enhancing the boundary representation of the resulting structure and reducing the computational cost of structured mesh refinements. In addition, a rich and thorough discussion of the main aspects of the parallel FreeFEM implementation is given in full detail. In particular, a version of the resulting code is provided for the reader convenience, including two benchmark examples for structural stiffness maximization and for the design of compliant mechanisms, showing the simplicity and effectiveness of the proposed implementation. Besides, we also show how the resulting code can be easily converted into a SIMP-based topology design algorithm. Since all the background knowledge on the topological derivative method is presented and the complete FreeFEM implementation is provided as supplementary material, this paper may also be used as educational/pedagogical material for graduate students and/or newcomers to the field of topology optimization.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"250 ","pages":"Article 104384"},"PeriodicalIF":3.5,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221768","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}

{"title":"Temperature fields calculation in heat exchangers using the finite element method","authors":"Jose M. Chaquet ,&nbsp;Pedro Galán del Sastre","doi":"10.1016/j.finel.2025.104385","DOIUrl":"10.1016/j.finel.2025.104385","url":null,"abstract":"<div><div>Heat exchanger (HEX) design is an optimization process that seeks to maximize heat transfer between two fluids while minimizing pressure drops. There are several conceptual design methods based on integral equations that only work with specific temperature values at the inlet and outlet of the HEX. However, it is very interesting to obtain approximate temperature distributions in these early stages of analysis to verify that the design criteria are met. To do this, it is necessary to solve systems of differential equations depending on the HEX configuration. Under certain assumptions, these equations have an analytical solution. However, in most cases it is only possible to obtain a numerical approximation. This work presents the solution of these equations for 6 HEX arrangements based on the finite element method. After validating the results in the cases whose analytical solution is known, the proposed method is applied to two realistic cases. Firstly, the effectiveness of a double-pass crossflow heat exchanger is studied. Since the inlet distributions in the second HEX module are not constant, no analytical solution is available. The numerical solution allows to analyze under what conditions the second pass is not effective due to thermal inversion. Secondly, a simplified 2D geometry of a compact intercooler HEX for hydrogen-fueled aero engine is solved. Specifically, an analysis is carried out to locate possible malfunctions due to obstructions of the fluid flows making use only of the metal temperature distributions at the outlets.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104385"},"PeriodicalIF":3.5,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170140","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}

{"title":"Optimization of point-melting strategies for the Electron Beam Melting process","authors":"Geovane Augusto Haveroth ,&nbsp;Carl-Johan Thore ,&nbsp;Roberto Federico Ausas ,&nbsp;Stefan Jakobsson ,&nbsp;José Alberto Cuminato ,&nbsp;Maicon Ribeiro Correa","doi":"10.1016/j.finel.2025.104356","DOIUrl":"10.1016/j.finel.2025.104356","url":null,"abstract":"<div><div>This study proposes an optimization methodology to find optimal heat source paths for point-melting in Electron Beam Melting (EBM) Powder Bed Fusion (PBF) processes, aiming to reduce the need for support structures and improve print quality. The building process is simulated using a time-dependent, one-way coupled, non-linear thermo-mechanical model, assuming negligible molten flow, with elastoplastic behavior and temperature-dependent material parameters. The goal of the optimization problem is to find heat source paths that minimize a global temperature measure with a penalty on excessive local temperatures. The numerical methodology is based on solving the non-linear partial differential equations via the Finite Element Method (FEM) and is applied in numerical examples for printing with titanium alloy Ti6Al4V. Metrics related to heat, residual displacement, and residual stresses are considered to assess the performance of different point-melting strategies and to compare optimized and conventional paths. The feasibility of the proposed optimization methodology for practical applications and alternatives towards future methodological advancements are discussed. The study provides a Python-based, MPI-parallelized implementation using open-source libraries and is made available for further research and applications.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104356"},"PeriodicalIF":3.5,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170141","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}

{"title":"Adaptive Interface-PINNs (AdaI-PINNs) for inverse problems: Determining material properties for heterogeneous systems","authors":"Dibakar Roy Sarkar ,&nbsp;Chandrasekhar Annavarapu ,&nbsp;Pratanu Roy","doi":"10.1016/j.finel.2025.104373","DOIUrl":"10.1016/j.finel.2025.104373","url":null,"abstract":"<div><div>We determine spatially varying discontinuous material properties using a domain-decomposition based physics-informed neural networks (PINNs) framework named the Adaptive Interface-PINNs or AdaI-PINNs (Roy et al., 2024). We propose the use of distinct neural networks for the field variables and material properties within each material, utilizing adaptive activation functions. While the neural networks across different materials share the same weights and biases, their activation functions are uniquely tailored using a hyperparameter that influences the slope of the activation function. The proposed framework is tested on several one-dimensional and two-dimensional benchmark examples, and its performance is compared with conventional PINNs and existing domain-decomposition PINNs frameworks, namely, the Multi-domain physics-informed neural network (M-PINN), and the eXtended physics-informed neural networks (XPINNs). The results demonstrate that the proposed approach can determine randomly distributed discontinuous material properties with an <span><math><msub><mrow><mi>L</mi></mrow><mrow><mn>2</mn></mrow></msub></math></span> error of <span><math><mrow><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> for the material property and the root-mean-square error of <span><math><mrow><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> for the primary variable while the other approaches yield errors that are approximately two orders of magnitude larger (that is, <span><math><mrow><mi>O</mi><mrow><mo>(</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span>). Moreover, the spatial distribution of material properties obtained using the proposed framework is in close agreement with the true distribution, whereas the other approaches fare much worse. Additionally, the proposed approach is approximately 40% faster than its competitors, indicating its potential as a robust alternative for solving inverse problems in heterogeneous materials.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104373"},"PeriodicalIF":3.5,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170139","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}

{"title":"An objective isogeometric formulation for nonlinear analysis of spatial Kirchhoff rods","authors":"Xiao Ren ,&nbsp;Haitao Wu ,&nbsp;Jiankang Bao ,&nbsp;Wei Chen ,&nbsp;Qianbo Xiao ,&nbsp;Dingzhou Guo ,&nbsp;Yazhou Liu","doi":"10.1016/j.finel.2025.104374","DOIUrl":"10.1016/j.finel.2025.104374","url":null,"abstract":"<div><div>Unlike traditional finite element analysis, isogeometric analysis (IGA) employs the Non-Uniform Rational B-Splines (NURBS) basis functions in computer aided design (CAD) as the interpolation functions. Many researchers have shown great interest in applying isogeometric analysis to nonlinear Kirchhoff rod problems. However, most existing studies have overlooked the objectivity of isogeometric elements for spatial Kirchhoff rods, i.e., the property such that the strain of a solid remains unchanged during finite rigid body motions. To this regard, an objective isogeometric formation is established in this study, based on a newly proposed an <em>updated smallest rotation (SR)</em> frame for reference. Such a frame will undergo the same rigid body rotation as the beam does, therefore objectivity can be naturally achieved, in contrast to the existing total SR frame. Furthermore, the NURBS interpolation for the infinitesimal displacements and rotations that can capture infinitesimal rigid body modes is applied in the predict phase, and thus a rigid-body qualified geometric stiffness matrix can be obtained. A series of numerical simulations have been conducted to verify the objectivity of the present formulation, and its advantage in calculation against the existing non-objective formulation is well demonstrated.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104374"},"PeriodicalIF":3.5,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170165","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}

{"title":"Role of the interphase zone in the effective mechanical properties and fracture modes of multiphase metal matrix composites at microscale","authors":"Szymon Nosewicz,&nbsp;Grzegorz Jurczak","doi":"10.1016/j.finel.2025.104390","DOIUrl":"10.1016/j.finel.2025.104390","url":null,"abstract":"<div><div>This study conducts a comprehensive numerical analysis to examine how the interphase zone influences the mechanical behavior of multiphase metal matrix composites at the microscale. A unit-cell model is developed within a finite element framework to capture the mechanical response of (a) interphase and particle deformation and damage, (b) a porous metal matrix, and (c) surface separation at two distinct interfaces. The material properties of the composite's key constituents are determined through a calibration process combining experimental testing and literature data. A series of simulations on unit-cell models with varying interphase characteristics are carried out to assess the effect of different plastic properties. Additionally, the role of interphase brittleness is investigated by modifying the failure strain to represent brittle, semi-ductile, and ductile behavior. By systematically varying interphase parameters, the study explores a broad spectrum of potential composite performance scenarios. Parametric studies are also conducted to analyze the behavior of interfaces between composite constituents. By adjusting cohesive strength and fracture energy, the model captures a wide range of bonding conditions—from weak to strong, and from brittle to ductile. The analysis identifies more than six distinct failure modes. Comparative stress-strain responses are used to highlight the influence of specific parameters on composite behavior. Key performance metrics such as toughness, ultimate tensile strength, and ductility are evaluated to illustrate the connection between microscopic features and macroscopic properties.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104390"},"PeriodicalIF":3.5,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144148098","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}

{"title":"High aspect ratio interface elements for mesoscale modelling of concrete under dynamic fracture propagation","authors":"Welington Hilário Vieira ,&nbsp;Daniel Dias-da-Costa ,&nbsp;Rodrigo Ribeiro Paccola","doi":"10.1016/j.finel.2025.104372","DOIUrl":"10.1016/j.finel.2025.104372","url":null,"abstract":"<div><div>Concrete can show an increased material strength under dynamic loading conditions, which is related to the heterogeneity at the mesoscale, as well as the rate of loading. The ability to capture this phenomenon and predict behaviour under dynamic fracture propagation is of interest to different applications. High aspect ratio interface elements are developed here for mesoscale modelling of concrete under dynamic loading while attending to the dynamic strength enhancement. The high aspect ratio interface elements can be implemented in standard finite element codes, as they are based on the same integration rules and shape functions as bulk elements. A rate-dependent constitutive model based on two damage variables is proposed to simultaneously handle fracture propagation in modes I and II, including the contribution of friction. A strategy is also proposed to avoid material iterations due to the coupled modes. The framework is validated using several examples, including mixed mode tests with different loading rates. In general, both load versus displacement curves and crack patterns are found to be close to the experimental results. The importance of the sample heterogeneity and the rate-dependent constitutive model could be observed as critical components to predict the results of dynamic experiments.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104372"},"PeriodicalIF":3.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134120","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}

{"title":"Second-order compatible-strain mixed finite elements for 2D compressible nonlinear elasticity","authors":"Mohsen Jahanshahi ,&nbsp;Damiano Pasini ,&nbsp;Arash Yavari","doi":"10.1016/j.finel.2025.104369","DOIUrl":"10.1016/j.finel.2025.104369","url":null,"abstract":"<div><div>In recent years, a new class of mixed finite elements—compatible-strain mixed finite elements (CSMFEs)—has emerged that uses the differential complex of nonlinear elasticity. Their excellent performance in benchmark problems, such as numerical stability for modeling large deformations in near-incompressible solids, makes them a promising choice for solving engineering problems. Explicit forms exist for various shape functions of first-order CSMFEs. In contrast, existing second-order CSMFEs evaluate shape functions using numerical integration. In this paper, we formulate second-order CSMFEs with explicit shape functions for the displacement gradient and stress tensor. Concepts of vector calculus that stem from exterior calculus are presented and used to provide efficient forms for shape functions in the natural coordinate system. Covariant and contravariant Piola transformations are then applied to transform the shape functions to the physical space. Mid-nodes and pseudo-nodes are used to enforce the continuity constraints for the displacement gradient and stress tensor over the boundaries of elements. The formulation of the proposed second-order CSMFEs and technical aspects regarding their implementation are discussed in detail. Several benchmark problems are solved to compare the performance of CSMFEs with first-order CSMFEs and other second-order elements that rely on numerical integration. It is shown that the proposed CSMFEs are numerically stable for modeling near-incompressible solids in the finite strain regime.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104369"},"PeriodicalIF":3.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144134121","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}

{"title":"Investigation of process-induced deformation in thermoplastic composites through sequential thermoforming simulation considering crystallization kinetics","authors":"Solmi Kim ,&nbsp;Dong-Hyeop Kim ,&nbsp;Sang-Woo Kim ,&nbsp;Soo-Yong Lee","doi":"10.1016/j.finel.2025.104389","DOIUrl":"10.1016/j.finel.2025.104389","url":null,"abstract":"<div><div>This study presents a predictive method for process-induced deformation (PID) and residual stress in a V-shaped carbon fiber reinforced thermoplastic composite (CFRTP) using sequential thermoforming simulations within integrated thermo-mechanical simulation framework implemented in ABAQUS with user-defined materials subroutine (UMAT). The FE-based thermoforming simulation incorporates theoretical models to consider crystallization effects and the mechanical behavior of CFRTP composite. The thermoforming process, consisting of forming, holding, and demolding stages, is analyzed in detail with respect to temperature distribution, residual stress evolution, and PID. A primary finding was that 1) the CFRTP deformed into a V-shape during forming, 2) residual stress was accumulated due to mechanical constraints in the holding stage, and 3) PID occurred upon demolding, resulting in a spring-in angle of 6.6°. This proposed methodology integrates multiple thermoforming simulations within integrated thermo-mechanical simulation framework, significantly improving computational efficiency and enabling rapid and precise prediction of effective material properties. By minimizing simulation complexity, it provides a practical tool for optimizing CFRTP-based structural and mold designs, reducing shape distortion, and enhancing the dimensional precision of thermoformed composite structures.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":"249 ","pages":"Article 104389"},"PeriodicalIF":3.5,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144138563","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}