Computers & Structures最新文献

{"title":"Optimal design of steel exoskeleton for the retrofitting of RC buildings via genetic algorithm","authors":"Jana Olivo,&nbsp;Raffaele Cucuzza,&nbsp;Gabriele Bertagnoli,&nbsp;Marco Domaneschi","doi":"10.1016/j.compstruc.2024.107396","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107396","url":null,"abstract":"<div><p>In recent decades, steel exoskeletons have gathered significant attention as a seismic retrofitting technique for existing structures. The design methods proposed so far are focused on the identification of the system's overall parameters through simplified models. Although these methodologies provide helpful guidance at the preliminary design stage, they do not consider aspects such as the distribution of the exoskeletons and sizing of their components. To overcome these limitations, an optimization process based on the Genetic Algorithm is proposed in this paper to identify the optimal exoskeleton number and spatial arrangement, and to determine the optimal size of their constituent elements. The algorithm aims to minimize the weight of the retrofit solution while keeping the whole existing structure in the elastic field and ensuring the structural verification of the exoskeleton's elements. The analyses have been conducted using a finite-element code with an Open Application Programming Interface, which allows the models to be handled through automatic routines. The proposed optimization tool has been applied to several case studies, considering two different layouts for the exoskeletons. Finally, the effectiveness of the retrofit method has been demonstrated, and the proposed optimization tool has been able to significantly reduce the weight and cost of the intervention.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924001251/pdfft?md5=a557eff10ce42bee0465f49fa4c59d16&pid=1-s2.0-S0045794924001251-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140879022","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":"A clustering-based partially stratified sampling for high-dimensional structural reliability assessment","authors":"Jinheng Song ,&nbsp;Jun Xu","doi":"10.1016/j.compstruc.2024.107390","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107390","url":null,"abstract":"<div><p>Assessing structural reliability problem with high-dimensional random inputs is still challenging due to the “curse of dimensionality”. In this paper, this challenge is addressed by extending the Generalized Distribution Reconstruction Method via Characteristic Function Inversion (GDRM-CFI). Specifically, a clustering-based partially stratified sampling method is proposed for selecting high-dimensional points to numerically evaluate the characteristic function (CF) curve of complex high-dimensional problems. An improved number-theoretical method (i-NTM) is used to establish a uniform, efficient point set, ensuring determinism and reducing variability. Subsequently, a partial stratification approach partitions the high-dimensional space into orthogonal two-dimensional subspaces. The fundamental point set is projected into each subspace, and the k-means clustering algorithm identifies centroids within each, acting as representative points. The complete set of representative points from all subspaces formulates the high-dimensional point set. Numerical examples are investigated, which demonstrate the proposed method is effective for high-dimensional structural reliability assessment.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140843043","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":"Design of truss structures with multiple eigenfrequency constraints via rank minimization","authors":"Anton Tkachuk ,&nbsp;Mykola M. Tkachuk","doi":"10.1016/j.compstruc.2024.107392","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107392","url":null,"abstract":"<div><p>Rank deficiency of the dynamic stiffness matrix is an indicator for resonance of a structure at a given frequency. This indicator can be exploited as a heuristic optimization objective to achieve resonance at several frequencies. Log-det heuristic provides a tractable surrogate function for matrix rank in the case of affine dependency of stiffness and mass matrices on design parameters, which applies to truss structures. Reducing the rank of the dynamic stiffness matrix for higher frequencies implies that the matrix is not semi-positive definite. For this case, the log-det heuristic is valid with a combination of interior-point methods and Fazel's semi-definite embedding via linear matrix inequalities. Further constraints on the fundamental frequency and compliance can be easily added within the framework as linear matrix inequalities. Several successful numerical examples illustrate the performance of the approach.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823312","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":"Corrigendum to “Asymptotically accurate and locking-free finite element implementation of first order shear deformation theory for plates” [Comput. Struct. 298 (2024) 107387]","authors":"K.C. Le ,&nbsp;H.-G. Bui","doi":"10.1016/j.compstruc.2024.107406","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107406","url":null,"abstract":"","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924001354/pdfft?md5=aff96b635256ab0dd000d985568de497&pid=1-s2.0-S0045794924001354-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140823313","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":"A finite element for nonlinear three-dimensional Kirchhoff rods","authors":"F. Armero","doi":"10.1016/j.compstruc.2024.107393","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107393","url":null,"abstract":"<div><p>This paper presents the formulation of a finite element method for nonlinear Kirchhoff rods (i.e. without transverse shear strain) in the general three-dimensional setting defined by a Cosserat director treatment of the cross sections attached to the rod's axis. The new element is based on a <span><math><msup><mrow><mi>G</mi></mrow><mrow><mn>1</mn></mrow></msup></math></span> interpolation of the rod's geometry in terms of Hermite shape functions of the rod's axis (including its tangent defining the tangential director), while the transversal directors defining the different bending and torsional responses of the rod consider a Lagrangian interpolation of the section directors. This direct interpolation of the directors, as opposed of underlying rotation vectors, assures the objectivity of the proposed formulation. In fact, the invariance properties of the resulting finite element are analyzed in detail, assuring the correct resolution of the local fundamental equilibrium relations between forces and moments, hence avoiding the so-called “self-straining” associated to separate treatments of the rod's geometry and its kinematics. Several representative numerical simulations are presented illustrating these properties as well as the appropriateness of the proposed formulation for the analysis of thin rods undergoing large finite deformations in the three-dimensional range.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140645516","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":"StructGNN: An efficient graph neural network framework for static structural analysis","authors":"Yuan-Tung Chou ,&nbsp;Wei-Tze Chang ,&nbsp;Jimmy G. Jean ,&nbsp;Kai-Hung Chang ,&nbsp;Yin-Nan Huang ,&nbsp;Chuin-Shan Chen","doi":"10.1016/j.compstruc.2024.107385","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107385","url":null,"abstract":"<div><p>In the field of structural analysis prediction via supervised learning, neural networks are widely employed. Recent advances in graph neural networks (GNNs) have expanded their capabilities, enabling the prediction of structures with diverse geometries by utilizing graph representations and GNNs' message-passing mechanism. However, conventional message-passing in GNNs doesn't align with structural properties, resulting in inefficient computation and limited generalization to extrapolated datasets. To address this, a novel structural graph representation, incorporating pseudo nodes as rigid diaphragms in each story, alongside an efficient GNN framework called StructGNN is proposed. StructGNN employs an adaptive message-passing mechanism tailored to the structure's story count, enabling seamless transmission of input loading features across the structural graph. Extensive experiments validate the effectiveness of this approach, achieving over 99% accuracy in predicting displacements, bending moments, and shear forces. StructGNN also exhibits strong generalization over non-GNN models, with an average accuracy of 96% on taller, unseen structures. These results highlight StructGNN's potential as a reliable, computationally efficient tool for static structural response prediction, offering promise for addressing challenges associated with dynamic seismic loads in structural analysis.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924001147/pdfft?md5=73db663c13a613e79e9bb992c8847367&pid=1-s2.0-S0045794924001147-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140645515","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":"A novel technique for low-velocity impact of shallow arches","authors":"Meng-Jing Wu ,&nbsp;Iftikhar Azim ,&nbsp;Xu-Hao Huang","doi":"10.1016/j.compstruc.2024.107386","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107386","url":null,"abstract":"<div><p>In the current study, an analytical model to analyze the low-velocity impact (LVI) response of metamaterial shallow arches subjected to rigid body impact is presented. The presented nonlinear model considers transverse deformation of the cross-section and geometric nonlinearity based on the higher-order shear theory and von Kármán nonlinearity. The research delves into three key aspects. The first is concerned with the establishment of a contact model to capture the contact characteristics between the impactor and the arch. The second aspect deals with the design of the member with Negative Poisson’s Ratio (NPR). The third aspect is concerned with the asymptotic solution of dynamic equations by using a two-perturbation technique. The proposed model is used to analyze the effects of auxetic, initial deformation, and foundation on the impact response and post-impact vibration of the arch. The results show that the contact area between the sphere impactor and the arch is elliptical. It is also noted that the contact force and indentation are highly dependent on the laminated configuration and auxetic properties. The study reveals that the presented model is a valid technique to evaluate the impact characteristics of metamaterial arches along with optimal design impact resistance of arches.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140646600","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":"Control of isolated response curves through optimization of codimension-1 singularities","authors":"Adrien Mélot ,&nbsp;Enora Denimal Goy ,&nbsp;Ludovic Renson","doi":"10.1016/j.compstruc.2024.107394","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107394","url":null,"abstract":"<div><p>We introduce a computational framework for controlling the location of isolated response curves, i.e. responses that are not connected to the main solution branch and form a closed curve in parameter space. The methodology relies on bifurcation tracking to follow the evolution of fold bifurcations in a codimension-2 parameter space. Singularity theory is used to distinguish points of isola formation and merger from codimension-2 bifurcations and an optimization problem is formulated to delay or advance the onset or merger of isolated response curves or control their position in the state/parameter space. We illustrate the methodology on three examples: a finite element model of a cantilever beam with cubic nonlinearity at its tip, a two-degree-of-freedom oscillator with asymmetry and a two-degree-of-freedom base-excited oscillator exhibiting multiple isolas. Our results show that the location of points of isola formation and mergers can effectively be controlled through structural optimization.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140641248","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":"Geometrically exact beam theory for gradient-based optimization","authors":"Taylor McDonnell,&nbsp;Andrew Ning","doi":"10.1016/j.compstruc.2024.107373","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107373","url":null,"abstract":"<div><p>Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this implementation of geometrically exact beam theory is its compatibility with forward and reverse-mode automatic differentiation. Another key feature is its support for both continuous and discrete adjoint sensitivity analysis. Other features are also presented which build upon previous implementations of geometrically exact beam theory, including a singularity-free rotation parameterization based on Wiener-Milenković parameters, an implementation of stiffness-proportional structural damping using a discretized form of the compatibility equations, and a reformulation of the equations of motion for geometrically exact beam theory as a semi-explicit system. Several examples are presented which verify the utility and validity of each of these features.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140640774","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":"Towards optimal use of the explicit β1/β2-Bathe time integration method for linear and nonlinear dynamics","authors":"Mohammad Mahdi Malakiyeh ,&nbsp;Zahra Anjomshoae ,&nbsp;Saeed Shojaee ,&nbsp;Saleh Hamzehei-Javaran ,&nbsp;Klaus-Jürgen Bathe","doi":"10.1016/j.compstruc.2024.107350","DOIUrl":"https://doi.org/10.1016/j.compstruc.2024.107350","url":null,"abstract":"<div><p>In an earlier publication, we proposed a new explicit time integration scheme, the <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub><mo>/</mo><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span>-Bathe method, which is simple in its formulation and showed remarkable accuracy in the solution of problems [1]. A particular strength of the method is that it can directly be used as a first-order or second-order scheme by a change of the values of <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span>. While good results are obtained with reasonable values of <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span>, for excellent accuracy better values of the parameters need to be chosen. We propose in this paper values of <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span> for the first-order scheme, best used in wave propagation analyses, and separate values for the second-order scheme, best used in analyses of structural vibrations. In each case, one set of values of <span><math><mrow><mo>(</mo><msub><mi>β</mi><mn>1</mn></msub><mo>,</mo><msub><mi>β</mi><mn>2</mn></msub><mo>)</mo></mrow></math></span> is given and to possibly improve the results only one of the parameters needs to be changed, that is, <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub></mrow></math></span> for wave propagations and <span><math><mrow><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span> for structural vibrations, making the scheme a one-parameter method. Another strength of the procedure is that physical damping can directly be included in the solution, the effect of which on the stability and accuracy of the solutions we analyze in the paper. The use of the solution scheme in nonlinear analysis is, as we show in the paper, a simple extension from linear analysis. Finally, we give various solutions using the explicit <span><math><mrow><msub><mi>β</mi><mn>1</mn></msub><mo>/</mo><msub><mi>β</mi><mn>2</mn></msub></mrow></math></span>-Bathe method in linear and nonlinear analyses to illustrate the performance of the method with the given recommendations for its use.</p></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140646643","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}