Finite Elements in Analysis and Design最新文献

{"title":"Impact of surface roughness on the formation of necking instabilities in additive manufactured porous metal plates subjected to dynamic plane strain stretching","authors":"","doi":"10.1016/j.finel.2024.104275","DOIUrl":"10.1016/j.finel.2024.104275","url":null,"abstract":"<div><div>This paper investigates the influence of surface roughness on multiple necking formation in additive manufactured porous ductile plates subjected to dynamic plane strain stretching. For this purpose, we have developed a computational model in ABAQUS/Explicit which includes surface texture and discrete voids measured from 3D-printed metallic specimens using optical profilometry and X-ray tomography analysis, respectively. The mechanical behavior of the material is described using an elastic–plastic constitutive model, with yielding defined by the isotropic von Mises criterion, an associated flow rule, and a power-law function for the yield stress evolution which depends on plastic strain, plastic strain rate, and temperature. The finite element calculations have been conducted across a broad range of strain rates, from <span><math><mrow><mn>5000</mn><mspace></mspace><msup><mrow><mtext>s</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> to <span><math><mrow><mn>50000</mn><mspace></mspace><msup><mrow><mtext>s</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>, to explore the interactions among inertia, surface roughness, and porosity in determining the necking pattern that emerges in the plates at large strains. The finite element results show that surface roughness induces perturbations in the deformation field of the specimen, which lead to early necking localization, while the location and number of necks formed are primarily controlled by the porous microstructure and the loading rate. The results for the neck spacing have shown quantitative agreement with the analytical stability analysis predictions and the unit-cell finite element calculations reported by Rodríguez-Martínez et al. <span><span>[1]</span></span>. Moreover, integrating discrete voids into simulations that already account for surface roughness results in a minor reduction in necking strain: surface roughness and porosity demonstrate similar quantitative impacts on necking ductility, which is primarily influenced by inertia effects at the highest strain rates studied. To the best of the authors’ knowledge, this paper presents the first calculations that explore dynamic plastic localization in additive manufactured metals, incorporating actual surface roughness and explicit void representation derived from experimental measurements. This work marks progress in the analysis of 3D-printed structures under impact loading, aiming to understand and predict the mechanics influencing their energy absorption capacity at high strain rates.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of nonlinear buckling of FGM shells using a high-order finite continuation approach","authors":"","doi":"10.1016/j.finel.2024.104273","DOIUrl":"10.1016/j.finel.2024.104273","url":null,"abstract":"<div><div>This study investigates the buckling behavior of cylindrical shells composed of Functionally Graded Materials (FGMs) when subjected to axial compression, challenging conventional assumptions regarding the influence of Poisson’s effect in homogeneous materials. To address this, we utilize a numerical approach employing the Asymptotic Numerical Method (ANM). Contrary to the expected linear pre-buckling behavior associated with a zero Poisson’s ratio, our findings reveal significant non-linearity in the response of FGM structures, emphasizing the influence of additional non-linear factors inherent in the behavior of advanced composites. Through an extensive numerical analysis conducted using a customized Matlab code, we examine the buckling and post-buckling characteristics of FGM shells with varying surface compositions, particularly focusing on configurations incorporating <span><math><mrow><msub><mrow><mi>Al</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span> and <span><math><mi>Al</mi></math></span> on the upper surface. To elucidate our findings, we present numerical examples comparing two FGM scenarios (<span><math><mrow><msub><mrow><mi>Al</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>/</mo><mi>Al</mi></mrow></math></span> and <span><math><mrow><mi>Al</mi><mo>/</mo><msub><mrow><mi>Al</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>O</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>) in terms of critical buckling and FGM distribution. Additionally, we validate our results by employing the commercial software Abaqus with Riks-based finite element method and Newton–Raphson solver.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593690","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":"Dual failure analysis of 3D structures under cyclic loads using bFS-FEM based numerical approaches","authors":"","doi":"10.1016/j.finel.2024.104272","DOIUrl":"10.1016/j.finel.2024.104272","url":null,"abstract":"<div><div>Failure mechanism of 3D structures cannot always be produced by the low-order finite elements due to the so-called volumetric locking effect. In this paper, dual numerical approaches based on the bubble face-based smoothed finite element method (bFS-FEM) are developed, ensuring that the locking problem is prevented and accurate load factors of elastic-perfectly plastic structures under cyclic actions are achieved. The failure mechanisms, in terms of plastic dissipation, are realized as incremental or alternative plastic failure modes, enabling different treatments in engineering practices. Moreover, the pseudo-static approach is capable of providing three-dimensional stress fields at the failure state, which is crucial for structural design. Interaction diagrams associated with various load-types and-ranges are illustrated in numerical experiments, showing that the bearing capacity envelopes of structures under cyclic loads are evidently smaller than that of proportional loads.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142573362","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":"3D analysis of reinforced concrete structural components using a multi-surface elasto-plastic-anisotropic-damage material model","authors":"","doi":"10.1016/j.finel.2024.104271","DOIUrl":"10.1016/j.finel.2024.104271","url":null,"abstract":"<div><div>Elastic-Plastic-Damage material models are widely adopted for the numerical modelling of concrete because of their capability of representing pressure sensitive 3D material behaviour considering permanent inelastic deformations as well as degradation of material moduli beyond the elastic range. In this paper, we develop a non-associative multi-surface plastic-damage material model for the 3D solid element based finite element analysis of reinforced concrete structural components. For the non-associative plastic flow, a linear potential function is adopted, while Menetrey–Willam and Rankine surfaces are adopted as the yield surfaces in compression and tension regimes, respectively. The degradation in the material stiffness under cyclic loading is incorporated by the damage component of the material model, which is generally anisotropic and assumed to be directly dependent on the evolution of the plastic strains. This assumption leads to a computationally efficient algorithm in terms of circumventing iterations to equate the stresses between the coupled damage and plasticity components of the material model. The rigorous details of the developed return-mapping methodology considering both the Cutting-Plane as well as the Closest-Point-Projection algorithms are provided. The material model is employed for the structural level analysis, in which case the concrete bulk is modelled by using an Eight-Node, Six-Degrees-Of-Freedom per-node solid element, and the reinforcement bars and stirrups are modelled by using the conventional Two-Node, Six-Degrees-Of-Freedom per-node Euler–Bernoulli beam-bar element. The inelastic behaviour of the reinforcements is determined by using a simpler elasto-plastic-damage based material model under the assumption of uni-axial stress-strain relations. An in-house fortran software is developed for the computer implementation. Comparisons with results from literature are shown for validation purposes. The validation cases include static analyses of a beam and a column under monotonic loading as well as a shear-wall under cyclic loading.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient thermal modeling of laser directed energy deposition using the forward Euler scheme: Methodology, merits and limitations","authors":"","doi":"10.1016/j.finel.2024.104270","DOIUrl":"10.1016/j.finel.2024.104270","url":null,"abstract":"<div><div>This paper explores mesoscale conduction-based modeling of Laser Directed Energy Deposition (LDED) for metallic materials. We benchmark the forward Euler (explicit) time integration strategy against the backward Euler (implicit) scheme using two experimentally validated simulations. Our results demonstrate the explicit scheme’s faster computational speed. Additionally, we identify previously overlooked flaws associated with its application in additive manufacturing. However, we also demonstrate that it encounters limitations when applied to LDED and highlight the need for a more stable explicit scheme.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530498","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":"Optimum thickness design method for micro-shell structure embedded in 3D macrostructure","authors":"","doi":"10.1016/j.finel.2024.104266","DOIUrl":"10.1016/j.finel.2024.104266","url":null,"abstract":"<div><div>In this study, we propose a multiscale thickness optimization method for designing micro-shell structure assuming that the macrostructure consists of multiple micro-shell structures. The micro-shell structures are connected to the macrostructure using the NIAH (Novel numerical implementation of asymptotic homogenization) method. The distributed thickness of the micro-shell structures is used as design variable. A squared error norm between actual and target displacements is minimized for controlling the displacements at arbitrary points of the macrostructure to the target values under the total volume constraint including the volume of the micro-shell structures. This design is formulated as a distributed optimization problem, and the thickness gradient function is theoretically derived. The derived sensitivity function is applied to the scalar-type H¹ gradient method to efficiently obtain the optimal thickness distribution of the micro-shell structures. Numerical examples demonstrate the effectiveness of the proposed method to optimize the thickness distribution of complex micro-shell structures.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445856","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 stopping criterion of iterative solvers for efficient computational cost reduction: Application to Navier–Stokes with thermal coupling","authors":"","doi":"10.1016/j.finel.2024.104263","DOIUrl":"10.1016/j.finel.2024.104263","url":null,"abstract":"<div><div>In this article, a strategy for efficient computational cost reduction of numerical simulations for complex industrial applications is developed and evaluated on multiphysics problems. The approach is based on the adaptive stopping criterion for iterative linear solvers previously implemented for elliptic partial differential equations and the convection–diffusion equation. Control of the convergence of iterative linear solvers is inferred from <em>a posteriori</em> error estimators used for anisotropic mesh adaptation. Provided that the computed error indicator provides an equivalent control on the discretization error, it is a suitable ingredient to assess when enough accuracy has been reached so that iterations of algebraic solvers can be stopped. In practice the iterative solution is stopped when the algebraic error is lower than a percentage of the estimated discretization error. The proposed method proves to be an effective cost-free strategy to reduce the number of iterations needed without degrading the accuracy of the solution. The discretization in the current work is based on stabilized finite elements, while the Generalized Minimal Residual method (GMRES) is used as iterative linear solver. Numerical experiments are performed of increasing complexity, from manufactured solutions to industrial configurations to evaluate the efficiency and the strengths of the proposed adaptive method.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-objective topological design considering functionally graded materials and coated fiber reinforcement","authors":"","doi":"10.1016/j.finel.2024.104269","DOIUrl":"10.1016/j.finel.2024.104269","url":null,"abstract":"<div><div>This study presents a multi-objective topology optimization method tailored to structures fabricated from functionally graded materials (FGMs), coated FGMs, and coated fiber-reinforced composite materials (FRCMs) with fixed fiber thickness. The design objective is the simultaneous minimization of elastic and thermal compliance. The material properties of these composite materials were derived to generate datasets using the representative volume element method under periodic boundary conditions. Subsequently, machine learning modules were developed based on the datasets to combine with the design process. The multi-objective optimization problem was addressed using the weighted sum method ensuring the generation of the Pareto front. The adaptive weighting strategy is employed to avoid biased results toward a single objective function. To define the coated boundaries within the design domain, image post-processing techniques such as convolution filters, interpolation schemes, and erosion methods were employed on the material layout information of the optimized FGM structures. Through numerical examples, optimized material layouts for coated assemblies incorporating FGMs and FRCMs are presented, with the performance verified through objective function values.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421814","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":"The influence of anomalies in supporting structures on the validation of finite-element blade bearing models","authors":"","doi":"10.1016/j.finel.2024.104268","DOIUrl":"10.1016/j.finel.2024.104268","url":null,"abstract":"<div><div>Finite-element analysis is the only means to determine the load distribution of large slewing bearings considering flexible bearing rings and supporting structures. For reliable results, the plausibility of the models need to be validated. Previous attempts on validating a finite-element model of a slewing bearing against measurement results have indicated a huge dependence of the deformation on tolerances in the supporting structures. This dependence has not yet been explored in research in favor of a focus on tolerances of the bearing itself. The present work explores different irregularities of the flange that connects to the outer ring of the bearing and their effects on bearing deformation. The results show that single dents or bulges on the flange and inclined flanges of the adapter ring significantly change the load distribution and contact angles of the bearing. They also aggravate the risk of truncation. For the calculated fatigue life however, the bearings seem to be robust to these uncertainties for the shown load cases. The dimensions of the investigated tolerances are verified by comparing the resulting deformations of the bearing outer ring against experimental data.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and experimental predictions of the static behaviour of thick sandwich beams using a mixed {3,2}-RZT formulation","authors":"","doi":"10.1016/j.finel.2024.104267","DOIUrl":"10.1016/j.finel.2024.104267","url":null,"abstract":"<div><div>This paper presents a numerical and experimental assessment of the static behaviour of thick sandwich beams using the mixed {3,2}-Refined Zigzag Theory (<span><math><mrow><mtext>RZ</mtext><msubsup><mi>T</mi><mrow><mo>{</mo><mrow><mn>3</mn><mo>,</mo><mn>2</mn></mrow><mo>}</mo></mrow><mrow><mo>(</mo><mi>m</mi><mo>)</mo></mrow></msubsup></mrow></math></span>). The displacement field of the <span><math><mrow><mtext>RZ</mtext><msubsup><mi>T</mi><mrow><mo>{</mo><mrow><mn>3</mn><mo>,</mo><mn>2</mn></mrow><mo>}</mo></mrow><mrow><mo>(</mo><mi>m</mi><mo>)</mo></mrow></msubsup></mrow></math></span> assumes a piecewise continuous cubic zigzag distribution for the axial contribution and a smoothed parabolic variation for the transverse one. At the same time, the out-of-plane stresses are assumed continuous a-priori: the transverse normal stress is given as a third-order power series expansion of the thickness coordinate, whereas the transverse shear one is derived through the integration of Cauchy's equation. The equilibrium equations and consistent boundary conditions are derived through a mixed variational statement based on the Hellinger-Reissner (HR) theorem and a penalty functional to enforce the strain compatibilities between the assumed independent stress fields and those obtained with the constitutive equations. Based on the proposed model, a simple C⁰-continuous two-node beam finite element is formulated (<span><math><mrow><mn>2</mn><mi>B</mi><mo>−</mo><mtext>RZ</mtext><msubsup><mi>T</mi><mrow><mo>{</mo><mrow><mn>3</mn><mo>,</mo><mn>2</mn></mrow><mo>}</mo></mrow><mrow><mo>(</mo><mi>m</mi><mo>)</mo></mrow></msubsup></mrow></math></span>). Firstly, the analytical and FE model accuracies of the presented formulation are addressed, and comparisons with the available three-dimensional elasticity solutions are performed. Subsequently, an experimental campaign is conducted to evaluate the static response of various thick sandwich beam specimens in three- and four-point bending configurations. The thick beam specimens are equipped with Distributed Fibre Optic Sensors (DFOS) embedded in the sandwich layup to measure axial deformation at the sandwich interfaces directly. Finally, the experimental data are compared with the available numerical models, highlighting the formulated numerical model's performances and limitations.</div></div>","PeriodicalId":56133,"journal":{"name":"Finite Elements in Analysis and Design","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}