{"title":"A discontinuous Galerkin method based isogeometric analysis framework for flexoelectricity in micro-architected dielectric solids","authors":"Saurav Sharma, Cosmin Anitescu, Timon Rabczuk","doi":"10.1016/j.compstruc.2024.107641","DOIUrl":"10.1016/j.compstruc.2024.107641","url":null,"abstract":"<div><div>Flexoelectricity, the generation of electric field in response to a strain gradient, is a universal electromechanical coupling, dominant only at small scales due to its requirement of high strain gradients. This phenomenon is governed by a set of coupled fourth-order partial differential equations (PDEs), which require <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> continuity of the basis in finite element methods for the numerical solution. While Isogeometric analysis (IGA) has been proven to meet this continuity requirement due to its higher-order B-spline basis functions, it is limited to simple geometries that can be discretized with a single IGA patch. For complex domains, e.g., architected materials, which require more than one patch for discretization, IGA faces the challenge of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>0</mn></mrow></msup></math></span> continuity across the patch boundaries. Here we present a discontinuous Galerkin method-based isogeometric analysis framework, capable of solving fourth-order PDEs of flexoelectricity in the domain of truss-based architected materials. An interior penalty-based stabilization is implemented to ensure the stability of the solution. The present formulation is advantageous over the analogous finite element methods since it only requires the computation of interior boundary contributions on the boundaries of patches. As each strut can be modeled with only two trapezoid patches, the number of <span><math><msup><mrow><mi>C</mi></mrow><mrow><mn>0</mn></mrow></msup></math></span> continuous boundaries is largely reduced. We consider four unit cells to construct the truss lattices and analyze their flexoelectric response. The truss lattices show a higher magnitude of flexoelectricity compared to the solid beam and retain this superior electromechanical response with the increasing size of the structure. This demonstrates the potential of architected materials to scale up flexoelectricity to larger scales, and achieve universal electromechanical response in meso/macro scale dielectric materials.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107641"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Continuum mechanics-based shell elements with six degrees of freedom at each node − the MITC4 / D and MITC4+ / D elements","authors":"Yeongbin Ko , Klaus-Jürgen Bathe , Xinwei Zhang","doi":"10.1016/j.compstruc.2024.107622","DOIUrl":"10.1016/j.compstruc.2024.107622","url":null,"abstract":"<div><div>We give the formulation and numerical assessment for using six degrees of freedom at each node of 4-node continuum mechanics-based quadrilateral shell elements. The formerly published MITC4 and MITC4 + shell elements are considered and extended to now include the drilling rotational degrees of freedom at the nodes. Including these degrees of freedom enables the modeling of shells with beam elements and shell surfaces intersecting at large angles and in addition results in an improvement of the membrane behavior of the elements. The elements pass all basic tests, show alleviated locking behavior in the analysis of general curved geometries and show close to optimal convergence behaviors in the analysis of the “all-encompassing” shell test problems.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107622"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pavel Trávníček, Jiří Němeček, Tomáš Koudelka, Jaroslav Kruis
{"title":"Impact of non-local damage formulation on chloride transport modeling in concrete","authors":"Pavel Trávníček, Jiří Němeček, Tomáš Koudelka, Jaroslav Kruis","doi":"10.1016/j.compstruc.2025.107648","DOIUrl":"10.1016/j.compstruc.2025.107648","url":null,"abstract":"<div><div>Reinforced concrete structures, such as roads and bridges, are exposed to chloride ingress, leading to steel reinforcement corrosion and reduced service life. Accurate numerical simulations of chloride ingress must account for damage caused by loading, as higher damage increases diffusion. This paper analyzes the impact of selected damage evolution laws and non-local formulations on the diffusion coefficient. The results show significant variations in load capacity (up to 20%) and damage extent (up to 72%) depending on the chosen model and averaging technique, which affects chloride diffusion modeling. Two diffusion models—Kurumatani et al. (2017) <span><span>[49]</span></span> and a new model by Trávníček et al. (2024) <span><span>[52]</span></span>—were compared for chloride penetration, with the latter validated using experimental data from a cracked reinforced concrete beam. Both diffusion models and four non-local damage variants were assessed in a Brazilian splitting test, showing differences in chloride concentration of up to 475%. This highlights the critical impact of selecting an appropriate damage model and a particular non-local formulation based on spatial averaging.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107648"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142985988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shishun Zhang, Xiao Xiao, Hanyu Chen, Jianping Xuan
{"title":"Accurate and flexible shape sensing of shell structures with polygonal inverse finite element method","authors":"Shishun Zhang, Xiao Xiao, Hanyu Chen, Jianping Xuan","doi":"10.1016/j.compstruc.2024.107638","DOIUrl":"10.1016/j.compstruc.2024.107638","url":null,"abstract":"<div><div>The inverse Finite Element Method (iFEM) based on triangular and quadrilateral elements faces significant challenges in complex shell structures due to slow convergence or poor mesh quality. In this study, a novel variable-node polygonal iFEM is developed to enhance the accuracy and flexibility of shape sensing for complex shell structures. Shear and membrane behaviors are respectively improved by the Mixed Interpolation of Tensorial Components (MITC) method and the Strain-Smoothed Element (SSE) method. Moreover, the precision of shape sensing at low mesh densities is improved through a polygonal Smoothing Element Analysis (SEA) method and an iFEM paradigm for curved shell elements based on MITC. Finally, numerical examples demonstrate that the polygonal iFEM achieves high-precision deformation reconstruction with less strain data, supports flexible mesh refinement and strain sensor deployment, and meets the shape sensing demands of shell structures with complex shapes and load conditions.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107638"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142911790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdelrahman Kamal Hamed , Mohamed Kamel Elshaarawy , Mostafa M. Alsaadawi
{"title":"Stacked-based machine learning to predict the uniaxial compressive strength of concrete materials","authors":"Abdelrahman Kamal Hamed , Mohamed Kamel Elshaarawy , Mostafa M. Alsaadawi","doi":"10.1016/j.compstruc.2025.107644","DOIUrl":"10.1016/j.compstruc.2025.107644","url":null,"abstract":"<div><div>Compressive strength is a key factor in the design and durability of concrete structures. Accurate prediction of compressive strength helps optimize material use and reduce construction costs. This study proposes a novel stacked model for predicting compressive strength, integrating three base models with linear regression. The base models include Artificial Neural Networks, Random Forest, and Extreme Gradient Boosting, while the stacked model uses Linear Regression as the metamodel. A dataset of 1,030 concrete mix samples covering eight critical input parameters, including cement, blast furnace slag, coarse aggregates, fine aggregates, fly ash, water, superplasticizer, and curing days, was used for training and evaluation. The dataset was split into training (80%), validation (10%), and testing (10%) subsets. The models were trained independently, and their predictions were used to develop the stacked model. Among the base models, the Extreme Gradient Boosting model achieved the highest accuracy, with an R<sup>2</sup> of 0.947 during testing. However, the stacked model outperformed it, attaining an R<sup>2</sup> of 0.953 in the testing phase. Shapley additive explanations analysis identified curing duration as the most influential factor in compressive strength prediction. A user-friendly graphical interface was developed to facilitate efficient prediction of compressive strength in concrete structures.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107644"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinneng Wang, Xiongfei Zhou, Kai Liu, Kaiyun Wang, Lin Jing
{"title":"Wheel-rail dynamic interaction induced by tread spalling integrating with pre-fatigue damage of materials","authors":"Jinneng Wang, Xiongfei Zhou, Kai Liu, Kaiyun Wang, Lin Jing","doi":"10.1016/j.compstruc.2024.107640","DOIUrl":"10.1016/j.compstruc.2024.107640","url":null,"abstract":"<div><div>Tread spalling is a typical damage type of wheel tread of railway vehicles, which produces severe wheel-rail dynamic interaction, further aggravating the deterioration of crucial components of vehicle and track, especially for coupling with fatigue damage of wheel/rail materials generated in the long-term operation. In this study, a comprehensive three-dimensional (3-D) wheel-rail transient contact finite element model was constructed, to investigate wheel-rail dynamic interaction by tread spalling, where dynamic mechanical properties of wheel-rail material under different equivalent service cycles were considered. The time- and frequency-domain responses of wheel-rail contact forces, wheel-rail adhesion-slip distribution and stress states during wheel rolling over tread spalling region were examined, and the wheel-rail plastic deformation and wear damage were also predicted. Influences of pre-fatigue damage (PFD) and strain rate effect (SRE) of materials on wheel-rail dynamic interactions were highlighted, in terms of the effects of train speed, spalling length and spalling depth. The results indicate that wheel-rail forces and stress are greatly raised as the wheel rolls over spalling region, resulting in large plastic strain and wear damage on the wheel and rail. The SRE significantly inhibits plastic deformation and exacerbates wear of the wheel and rail, while PFD increases plastic deformation but mitigates wear damage to the wheel-rail system. The train speed and spalling length both have a notable effect on plastic strain and wear damage of wheel and rail, while spalling depth only has an obvious influence on the wheel. The detailed modelling and obtained results are beneficial for spalling identification in dynamic detection and reasonable maintenance of wheel-rail system.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107640"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Godfred Oheneba Agyekum , Laurent Cangémi , François Jouve
{"title":"Homogenization based topology optimization of a coupled thermal fluid-structure problem","authors":"Godfred Oheneba Agyekum , Laurent Cangémi , François Jouve","doi":"10.1016/j.compstruc.2024.107636","DOIUrl":"10.1016/j.compstruc.2024.107636","url":null,"abstract":"<div><div>This article focuses on the topology optimization of a weakly coupled three physics problem. The structures are made of periodically perforated material, where the microscopic periodic cell is macroscopically modulated. The objective is to optimize the homogenized formulation of this system, where the coupling is weak because the three physics involved are solved consecutively: first, a coupled fluid flow is determined using the Biot-Darcy's law for the fluid domain, second, a thermal model using the convection-diffusion equation for the whole domain, and third, a three-physics problem by solving the linear poro-thermo elasticity problem in the solid domain. This approach allows low computational cost of evaluation of load sensitivities using the adjoint-state method. Two-dimensional and three-dimensional numerical problems are presented using the alternate directions algorithm. It is demonstrated how the implementation makes it possible to treat a variety of design problems.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107636"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mojtaba Aliasghar-Mamaghani , Ioannis Koutromanos , Carin Roberts-Wollmann , Matthew Hebdon
{"title":"Multiphysics Modeling of Chloride-Induced Corrosion Damage in Concrete Structures","authors":"Mojtaba Aliasghar-Mamaghani , Ioannis Koutromanos , Carin Roberts-Wollmann , Matthew Hebdon","doi":"10.1016/j.compstruc.2025.107643","DOIUrl":"10.1016/j.compstruc.2025.107643","url":null,"abstract":"<div><div>This paper presents a computational scheme describing the formation and evolution of cracks in concrete structures due to chloride-induced corrosion in reinforcing or prestressing steel. The scheme accounts for coupled heat, moisture and chloride transport, while phenomenologically describing the kinetics of the electrochemical corrosion reaction in steel, formation of expansive corrosion products, and subsequent formation of stresses and cracks in concrete. Advective and diffusive chloride transport mechanisms are considered. The increase in concrete permeability against moisture and chloride transport due to cracking is considered in the constitutive laws. Novel equations are proposed to accurately describe the expansion of corrosion products. The scheme is calibrated using data from small-scale tests in the literature. Subsequently, it is applied to the simulation of real-life prestressed concrete bridge beams that exhibited corrosion-induced cracking after decades of service. The boundary conditions represent the ambient climate data, obtained from weather stations near the bridges. The analyses reproduce the observed cracking damage and enable the investigation of the validity of modeling assumptions commonly adopted in analytical studies for concrete infrastructure durability. The results also emphasize the significance of cracking on the evolution and spatial distribution of chloride content and on the extent of corrosion.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107643"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phase-field modeling of brittle anisotropic fracture in polycrystalline materials under combined thermo-mechanical loadings","authors":"Raj Kiran , Krishana Choudhary , Nhon Nguyen-Thanh","doi":"10.1016/j.compstruc.2025.107651","DOIUrl":"10.1016/j.compstruc.2025.107651","url":null,"abstract":"<div><div>Phase-field modeling, owing to the regularized representation of discrete crack topologies, provides an efficient and robust framework for simulating complex fracture mechanisms in brittle materials. This study proposes an adaptive isogeometric-based approach to comprehend the fracture behaviour of polycrystalline materials under different thermo-mechanical loadings. The model considers anisotropy in the fracture resistance to examine intergranular and transgranular fracture mechanisms in polycrystalline materials. The individual grains in the morphology are modelled as anisotropic linear elastic domains possessing random preferential cleavage orientations. The present adaptive isogeometric framework uses polynomial splines over hierarchical T-meshes which offers an efficient adaptive mesh refinement scheme employing the phase-field parameter as an error indicator. Additionally, a hybrid-staggered scheme is implemented where the displacement field is computed using an isotropic model (no tension–compression splitting), while the phase-field parameter is evaluated based on an anisotropic model (with tension–compression splitting). The effect of thermo-mechanical coupling is examined on the fracture loads, and it is observed that the effects of temperature on the fracture loads are insignificant, however, it may accelerate or delay the fracture process. A series of numerical examples dealing with the fracture behaviour of single crystal, bicrystals, and polycrystalline domains are presented to showcase the robustness and capability of the present adaptive isogeometric framework.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107651"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143055222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Frequency-dependent mass, elastic and geometric stiffness matrices of an axially loaded Timoshenko-Ehrenfest beam with applications","authors":"J.R. Banerjee","doi":"10.1016/j.compstruc.2024.107599","DOIUrl":"10.1016/j.compstruc.2024.107599","url":null,"abstract":"<div><div>Earlier research on the development of explicit algebraic expressions for the elements of the frequency-dependent mass, elastic and geometric stiffness matrices for free vibration analysis was carried out on Bernoulli-Euler, Timoshenko-Ehrenfest and axially loaded Bernoulli-Euler beams. Seeking solution for the correspondingly more difficult problem for an axially loaded Timoshenko-Ehrenfest beam seemed too difficult at the time when these earlier developments took place. Now, with the experience and knowledge gained, the difficulty is overcome in part by enhanced application of symbolic computing. Thus, the explicit algebraic expressions for the elements of the frequency-dependent mass, elastic and geometric stiffness matrices of an axially loaded Timoshenko-Ehrenfest beam are derived from first principles. The equivalency of these matrices when added altogether, with the dynamic stiffness matrix is ensured. The derived matrices are then applied using the Wittrick-Williams algorithm as a solution technique to investigate the free vibration characteristics of some illustrative examples. The results are discussed, and significant conclusions are drawn. The proposed method preserves the exactness of results in the same way as the dynamic stiffness method, but importantly, it opens the possibility of including damping in free vibration and response analysis when using exact methods such as the dynamic stiffness method.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"308 ","pages":"Article 107599"},"PeriodicalIF":4.4,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142936020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}