Adrian Humphry, Mehran Ebrahimi, Nigel Morris, Adrian Butscher
{"title":"An interface-preserving level set update strategy for topology optimisation of mechanical assemblies","authors":"Adrian Humphry, Mehran Ebrahimi, Nigel Morris, Adrian Butscher","doi":"10.1016/j.compstruc.2025.107973","DOIUrl":"10.1016/j.compstruc.2025.107973","url":null,"abstract":"<div><div>Structural components in assemblies often require specific geometric features — such as cylindrical regions for joints — to function correctly. Standard topology optimisation methods, however, struggle to impose geometric, feature-preserving constraints on selected boundary regions during shape updates. We propose a shape update strategy for level set-based topology optimisation of mechanical assemblies that enables constrained shape updates along user-specified boundaries while allowing free-form updates elsewhere. The constrained regions are limited to affine motions such as translation, rotation, and scaling, providing greater control that is especially valuable in engineering design. This is particularly useful for multi-functional components in larger assemblies, where certain boundaries must retain primitive geometries and vary only within specified limits. For example, when a component must contain a cylindrical aperture to fit a pin of unknown radius, our method allows simultaneous optimisation of the aperture’s location, orientation, and size, alongside the component’s overall topology. We extend the standard Hilbert space extension method by introducing its constrained variant which incorporates affine motion constraints into the velocity extension. The resulting velocity field satisfies descent direction requirements for the optimisation while ensuring that all feature-preserving constraints are met. We demonstrate the method’s effectiveness on canonical structural problems with geometrically constrained boundaries.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"319 ","pages":"Article 107973"},"PeriodicalIF":4.8,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261940","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}
Baozhi Han , Deshun Yin , Yunfei Gao , Shaopeng Qin , Liangzhu Ma , Roman Wan-Wendner
{"title":"A 3D fractional viscoelastic damage model for thermosetting polymer composites: Theory and FEM implementation","authors":"Baozhi Han , Deshun Yin , Yunfei Gao , Shaopeng Qin , Liangzhu Ma , Roman Wan-Wendner","doi":"10.1016/j.compstruc.2025.107975","DOIUrl":"10.1016/j.compstruc.2025.107975","url":null,"abstract":"<div><div>Driven by advances in structural reinforcement, composite technologies, and new energy systems, there is a growing engineering demand for epoxy resin-based materials, particularly in bonding, mechanical deformation, and damage management applications. Building an accurate constitutive model is essential for better understanding its deformation characteristics and improving the design of polymer-based material products. However, material damage degradation cannot be well captured by viscoelastic models while elasto-viscoplastic models need more parameters. In this study, a fractional viscoelastic damage model based on fractional calculus theory is developed to characterize the stress soften and nonlinear response of polymer-based materials, suitable for implementation in finite element software. An improved variable-order fractional damage evolution equation for 3D applications is proposed and successfully implemented in a user-defined subroutine via the finite difference method, with the complete modeling framework realized in commercial software Abaqus. Then, uniaxial tension and compression tests of epoxy-based materials were simulated in Abaqus, and corresponding error analyses were performed to show model’s accuracy. Furthermore, equi-biaxial tensile simulations of a cruciform specimen were carried out, confirming the model’s applicability under multiaxial loading. Moreover, the dependence of fractional parameters on material state variables provides useful perspectives for epoxy adhesive design and processing.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107975"},"PeriodicalIF":4.8,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261942","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":"Free vibration and global sensitivity analysis of perforated composite skew shallow shells on elastic foundations","authors":"Sabyasachi Ghosh, Salil Haldar","doi":"10.1016/j.compstruc.2025.107972","DOIUrl":"10.1016/j.compstruc.2025.107972","url":null,"abstract":"<div><div>This paper deals with the development of a finite element model for the free vibration analysis of laminated composite skew shallow shells resting on a two-parameter elastic foundation and containing cutouts. The first-order shear deformation theory, including rotatory inertia effects, has been employed to model the shell deformations. A nine-node isoparametric finite element formulation with five degrees of freedom that achieves C<sup>0</sup> continuity of the displacement and rotation fields across inter-element boundaries has been developed. Numerical examples show excellent accuracy and convergence characteristics of the present formulation for shallow shells having a planform length to shell curvature ratio of up to 0.5. A sensitivity analysis of the skew shell parameters with cutouts and elastic foundations using a Gaussian process machine learning based surrogate modelling technique has been proposed. New results of free vibration analysis of skew shallow shells with cutouts are presented, and the combined effects of skew geometry, cutouts, and elastic foundation on the frequency response of curved shells are discussed. The proposed methodology provides a computationally efficient and accurate framework for the dynamic analysis of complex laminated composite skew shallow shell structures.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107972"},"PeriodicalIF":4.8,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261943","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}
Qingdi Wang , Lucas Oliveira Siqueira , Tao Xu , Min Zhao , Renato Picelli , Yi Min Xie
{"title":"Topology optimization of fluid–structure interaction problems with buckling constraints","authors":"Qingdi Wang , Lucas Oliveira Siqueira , Tao Xu , Min Zhao , Renato Picelli , Yi Min Xie","doi":"10.1016/j.compstruc.2025.107978","DOIUrl":"10.1016/j.compstruc.2025.107978","url":null,"abstract":"<div><div>In many engineering applications, structures immersed in fluid flow must withstand not only external moving fluid loading but also potential instabilities arising from fluid–structure interaction. Fluid-induced instabilities such as structural buckling, can lead to sudden and catastrophic failures, especially in slender structural members in compression. While classic fluid–structure interaction topology optimization studies often focus on improving stiffness or reducing mass, the possibility of buckling under fluid-induced loads has not yet been considered. To address this gap, we proposed a framework to incorporate buckling constraints into fluid–structure interaction topology optimization. This enables the design of structures that are not only lightweight and stiff but also stable. We have extended the existing topology optimization of binary structure method with augmented Lagrangian multipliers to stably optimize fluid–structure interaction problems with buckling constraints. Numerical examples validate the efficacy of the proposed approach, demonstrating significant improvements in optimized structures for stability against buckling. To the best of the authors’ knowledge, this is the first study considering stability for fluid–structure interaction optimization. The proposed buckling-constrained optimization framework for fluid–structure interaction problems benefits the engineering design of hydrodynamic and aerodynamic structures towards practical application.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107978"},"PeriodicalIF":4.8,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261944","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":"Implicit s-sub-step time integration schemes with (s+1)th-order accuracy and dissipation control","authors":"Chanju Lee, Gunwoo Noh","doi":"10.1016/j.compstruc.2025.107949","DOIUrl":"10.1016/j.compstruc.2025.107949","url":null,"abstract":"<div><div>We propose a family of higher-order implicit <em>s</em>-sub-step time integration methods achieving (<em>s</em>+1)th-order accuracy and dissipation control for 2≤<em>s</em>≤5 for the systems under external loadings. These schemes allow users to control numerical dissipation through a parameter <span><math><msub><mi>ρ</mi><mi>∞</mi></msub></math></span>. The methods do not require acceleration vectors during calculations; accelerations can be obtained using a simple process based on higher-order finite differences of the displacements, if needed. To maintain the order of accuracy in systems with external forces, we model the external force at the last sub-step. We present results from several linear and nonlinear examples to validate our theoretical findings, indicating that the proposed method offers more accurate responses compared to conventional methods with similar or reduced computational costs. The MATLAB source code implementing the proposed methods is available at: <span><span>https://github.com/LeeChanJuKor/HDSUCI.git</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107949"},"PeriodicalIF":4.8,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220684","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}
Arka Maity , Amit Kanvinde , Diego I. Heredia Rosa , Albano de Castro e Sousa , Dimitrios G. Lignos
{"title":"A torsional fiber element and a multiaxial softening model to simulate cyclic interactive buckling in wide-flanged steel members","authors":"Arka Maity , Amit Kanvinde , Diego I. Heredia Rosa , Albano de Castro e Sousa , Dimitrios G. Lignos","doi":"10.1016/j.compstruc.2025.107970","DOIUrl":"10.1016/j.compstruc.2025.107970","url":null,"abstract":"<div><div>A three-dimensional frame-element based approach is presented to simulate cyclic inelastic interactions of local and lateral torsional buckling – collectively termed interactive buckling. The approach integrates a multiaxial fiber-based beam-column element termed the torsional fiber element, capable of representing deformation modes characteristic of inelastic warping and St Venant torsion with a multiaxial constitutive model that represents the effective constitutive response associated with cyclic inelastic local buckling. The resulting integrated approach, implemented in the platform OpenSees is applied to 26 beam-column specimens encompassing a range of configurations including section geometry and boundary conditions and loading protocols. The results of the approach are evaluated against counterpart results from physical experiments as well as continuum finite element simulations. It is determined that the presented approach can simulate important aspects of interactive buckling both qualitatively and quantitatively, including deformation modes, as well as cyclic strength and stiffness degradation, while requiring only a fraction of the computational time of the continuum-finite element simulations. Guidelines for calibration and use of the approach are presented. Limitations of the approach are summarized, along with directions for future improvements.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107970"},"PeriodicalIF":4.8,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220682","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}
Jun Zhang , Tong Zhang , Lu Guo , Xiaodan Wang , Xiaochun Zhang , Ying Wang
{"title":"Graph-based digital twin modeling for dynamic simulation of continuous beam bridges subjected to unknown loads","authors":"Jun Zhang , Tong Zhang , Lu Guo , Xiaodan Wang , Xiaochun Zhang , Ying Wang","doi":"10.1016/j.compstruc.2025.107969","DOIUrl":"10.1016/j.compstruc.2025.107969","url":null,"abstract":"<div><div>Digital twin modelling can significantly contribute to accurate and efficient structural analysis and condition identification, whereas existing methods face challenges in simulating structural dynamic responses under unknown load conditions. To address this issue, the present study proposes a Graph-based Digital Twin Modelling (GDTM) method to simulate the dynamic responses of bridge structures without prior knowledge of the external loads. The method uses heterogeneous adjacency matrices to aggregate adjacent measurement responses. A three-span continuous beam bridge and its scaled experimental model are used to validate the proposed method. The results demonstrate that the GDTM method can simulate structural dynamic responses accurately even with unknown loads, achieving a normalized mean squared error (NMSE) of 0.29 for the real bridge and 0.48 for the scaled experimental model, representing an accuracy improvement of over 76 % compared to FEM and 59 % compared to other graph-based methods. Although the model training takes over 15 hours, the simulation takes less than 2 seconds, which is a 28-fold improvement in simulation efficiency compared to FEM. The proposed GDTM method provides a promising solution for digital twin modelling, which may find broad applications in structural operation and maintenance.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107969"},"PeriodicalIF":4.8,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220683","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":"Extended fatigue response spectrum method for vibration fatigue assessment of aerospace components under multi-support excitation","authors":"Guohao Sui, Shanteng Yan, Yahui Zhang","doi":"10.1016/j.compstruc.2025.107967","DOIUrl":"10.1016/j.compstruc.2025.107967","url":null,"abstract":"<div><div>Classical uniform excitation models are insufficient to reflect the complex vibration environments of aerospace components. To address this limitation, this paper focuses on the fatigue life assessment of aerospace components subjected to complex excitations, proposes an efficient extended fatigue response spectrum method (E-FRSM), and investigates the effects of multi-support excitation on vibration fatigue. The E-FRSM, an efficient strategy, consists of a novel calculation format and a broadened fatigue damage response spectrum (FDRS), addressing the multi-support excitation and mode truncation error through quasi-static responses. The calculation format is constructed by employing the analogy to the Projection by Projection criterion twice, converting the total damage into a weighted summation of the modal and quasi-static damage contributions. Further, the damage response, which quantifies the contribution of modal and quasi-static responses, is condensed from the damage contribution and used to establish the broadened FDRS. A problem-independent training model is then developed using a radial basis function neural network. In the numerical examples, the reliability and efficiency of the E-FRSM are discussed, as well as the effect of multi‑support excitation on the accuracy of frequency-domain methods. The dramatic impact of multi‑support excitation on vibration fatigue is investigated, with the underlying mechanism revealed from the perspective of PSD.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107967"},"PeriodicalIF":4.8,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221237","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":"A generalizable gated graph recurrent unit (Graph-GRU) network for nonlinear response prediction of cross-structures","authors":"Shan He , Shunyao Wang , Ruiyang Zhang","doi":"10.1016/j.compstruc.2025.107968","DOIUrl":"10.1016/j.compstruc.2025.107968","url":null,"abstract":"<div><div>Accurate seismic response prediction is essential for structural safety and resilience in civil engineering. Recently, artificial intelligence has emerged as a powerful tool for efficiently modeling the response of highly nonlinear structures. However, existing models struggle to generalize across diverse structural systems, which remains a bottleneck in deep learning-enabled surrogate modeling of nonlinear structures. This paper introduces a graph gated recurrent unit network (Graph-GRU) designed to achieve generalized nonlinear structural response prediction across different structures under unseen earthquakes. The core innovation lies in the specific design of the network by integrating both seismic excitations and structural characteristics into the GRU hidden state to learn the dynamic properties of different structures and achieve the generalizability to unseen structures. Here, the structural characteristics are featured using a graph convolutional network based on the structural graph with arbitrary degrees-of-freedom. Three pooling strategies including max, average, and attention pooling are considered to calculate the global structural feature vector. Additionally, the proposed approach is compared to the state-of-the-art deep learning models. The generalizability performance of the proposed Graph-GRU network is validated across 40 unseen reinforced concrete (RC) frames with varying design parameters of story heights and floor mass distributions. Results demonstrate that the proposed Graph-GRU is capable of predicting nonlinear responses of diverse unseen structures, effectively addressing the major generalizability challenge of existing methods.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107968"},"PeriodicalIF":4.8,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145221238","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":"Multiscale numerical investigation on microstructure characteristics with the effect of flow field under different process conditions","authors":"Yuewei Ai , Yang Zhang , Shibo Han , Yi Huang","doi":"10.1016/j.compstruc.2025.107965","DOIUrl":"10.1016/j.compstruc.2025.107965","url":null,"abstract":"<div><div>Microstructure characteristics formed in the solidification process of molten pool are closely related to the mechanical performances of welded joints. A macro–micro multiscale model is established to calculate the solidification behavior during the laser welding process. The effectiveness of developed model is verified by the consistency between experimental and simulation results. Based on the established model, the effect of transient flow field on microstructure characteristics is analyzed. Furthermore, the temperature field, transient solidification conditions and microstructure characteristics under different process conditions are discussed in details. The results show that the columnar grain during the laser welding process with considering the transient flow field gradually deviates from the vertical direction and exhibits a slightly curved morphology characteristic compared to that without considering the transient flow field. The number of solute-enriched droplets in residual liquid region is decreased and the uniformity of solute concentration distribution is improved with the laser power increasing. The maximum solute concentration and solute segregation degree in columnar grain growth region are increasing gradually with the increase in welding speed. The proposed model is beneficial for understanding microstructure evolution during the laser welding process and refining weld microstructure to enhance the welding quality.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"318 ","pages":"Article 107965"},"PeriodicalIF":4.8,"publicationDate":"2025-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145109230","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}