Computers & Structures最新文献

{"title":"Data-driven FEM cluster-based basis reduction method for ultimate load-bearing capacity prediction of structures under variable loads","authors":"Yinghao Nie,&nbsp;Xiuchen Gong,&nbsp;Gengdong Cheng,&nbsp;Qian Zhang","doi":"10.1016/j.compstruc.2024.107593","DOIUrl":"10.1016/j.compstruc.2024.107593","url":null,"abstract":"<div><div>The structural ultimate load-bearing capacity plays an influential role in engineering applications. Melan’s static shakedown theorem offers a valuable approach for predicting the lower bound of shakedown loading factors and providing a safer shakedown domain when the structures are subjected to cyclic variable loads. However, the associated nonlinear mathematical programming is plagued by substantial computational expenses due to excessive design variables and constraints. Inspired by the data-driven FEM Cluster-based Analysis (FCA) <span><span>[44]</span></span>, <span><span>[45]</span></span>, <span><span>[46]</span></span>, <span><span>[47]</span></span> for predicting nonlinear effective properties of RVE of heterogeneous materials very efficiently, this paper introduces a novel FEM cluster-based basis reduction method to predict the shakedown domain of structures. Firstly, the FEM elements of discretized structures are grouped into several clusters using the elastic strain tensor under different load vertex cases, which differs from the orthogonal loading conditions for clustering RVE. In this way, similar mechanical behavior in each cluster of the structures is expected in future loading. Then, the cluster eigenstrain-driven algorithm is employed to construct the self-equilibrium stress (SES) basis vectors, which should satisfy the equilibrium equation and statical boundary condition. Furthermore, the essential time-independent beneficial residual stress in the static shakedown analysis is represented as a linear combination of the constructed SES basis vectors based on the basis reduction method, which can reduce a large number of time-independent residual stress to several linear combination coefficients. In addition, the reduced-order model (ROM) is constructed by the cluster SES, which are volume averaged stresses of the element SES basis vectors within each cluster. Based on the ROM, a constraint reduction strategy (CRS) is introduced to selectively remove stress constraints significantly below yield stress from the enormous element-wise yield constraint set. These innovations decrease the number of design variables and nonlinear constraints in the shakedown optimization, thus significantly enhancing computational efficiency. Several numerical examples illustrate the effectiveness and efficiency of the proposed shakedown analysis method of FCA.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"306 ","pages":"Article 107593"},"PeriodicalIF":4.4,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142723437","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":"Efficient methods to build structural performance envelopes in characteristic load space","authors":"S. Sheshanarayana ,&nbsp;C.G. Armstrong ,&nbsp;A. Murphy ,&nbsp;T.T. Robinson ,&nbsp;N.L. Iorga ,&nbsp;J.R. Barron","doi":"10.1016/j.compstruc.2024.107595","DOIUrl":"10.1016/j.compstruc.2024.107595","url":null,"abstract":"<div><div>Performance envelopes provide a novel methodology that quantifies the load bearing capacity of a structure in a reduced dimension load space. The envelopes relate the complex loads acting on a structure to the corresponding structural failure constraints and may find many applications within the aircraft structural design process. Constructing envelopes for industrial problems is of particular interest, where the state-of-the-art implementation involves a point cloud meshing and surface modelling strategy. A main challenge in implementing envelopes within an engineering process is the large associated computational costs of construction. The contribution of this article is a robust and efficient strategy to reduce the computational costs of building a performance envelope. The paper presents a method to build the envelopes using a ray-scaling approach. The novel approach is validated by building 3-dimensional envelopes for a representative industrial problem (stiffened panels of AIRBUS’s XRF-1 wing). The results demonstrate a ∼ 42 % reduction in the computation costs compared to the preceding research. The improved construction efficiency makes the employment of envelopes more feasible for large industrial scale processes or when individual failure assessments are computationally expensive.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"306 ","pages":"Article 107595"},"PeriodicalIF":4.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718510","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 non-classical computational method for modelling functionally graded porous planar media using micropolar theory","authors":"AbdolMajid Rezaei ,&nbsp;Razie Izadi ,&nbsp;Nicholas Fantuzzi","doi":"10.1016/j.compstruc.2024.107590","DOIUrl":"10.1016/j.compstruc.2024.107590","url":null,"abstract":"<div><div>The current study proposes a computational-based method to employ the non-classical micropolar continuum for modelling plates with in-plane functionally graded porosities. Initially, a homogenisation method is developed to derive the micropolar parameters of porous heterogenous plates based on strain energy equivalence in various designed deformations simulated via finite element analysis. The modelling procedure is further augmented to accommodate structures with functionally graded porosities. The established method offers an effective framework for studying the mechanical behaviour of porous plates with various porosity distributions and a wide range of aspect ratios. Results indicate that the micropolar theory-based modelling surpasses traditional Cauchy theory in accurately predicting the stiffness and displacement distribution of the FG porous structures. The novelty of this study lies in the integration of micropolar theory with the homogenisation of graded porosity patterns, offering enhanced predictions for materials with microstructural features. Additionally, a custom finite element formulation is developed in COMSOL to implement micropolar elasticity, significantly improving the computational efficiency to account for complex geometry, loading, and boundary conditions. To show the applicability of the method, the modelling is used to design a dental implant with its functional property mimicking that of the natural bone to avoid stress-shielding while ensuring proper occlusivity.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"306 ","pages":"Article 107590"},"PeriodicalIF":4.4,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718563","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 Cepstrum-Informed neural network for Vibration-Based structural damage assessment","authors":"Lechen Li ,&nbsp;Adrian Brügger ,&nbsp;Raimondo Betti ,&nbsp;Zhenzhong Shen ,&nbsp;Lei Gan ,&nbsp;Hao Gu","doi":"10.1016/j.compstruc.2024.107592","DOIUrl":"10.1016/j.compstruc.2024.107592","url":null,"abstract":"<div><div>Data-driven methods for vibration-based Structural Health Monitoring (SHM) have gained significant popularity for their straightforward modeling process and real-time tracking capabilities. However, developing complex models such as deep neural networks can pose challenges, including limited interpretability and substantial computational demands, due to the large number of parameters and deep layer stacking. This study introduces a novel Cepstrum-Informed Attention-Based Network (CIABN) developed to model power cepstral coefficients of structural acceleration responses, guided by cepstrum-based physical properties to facilitate efficient structural damage assessment. The CIABN integrates three key components: a unique input–output mapping based on weighted cepstral coefficients, a novel cepstral positional encoding mechanism, and a multi-head self-attention mechanism. The unique input–output mapping enables appreciable model generalization in overall structural characteristics, with the weighted cepstral coefficients serving as informative and compact data for efficient neural network modeling. The developed cepstral positional encoding scientifically guides the model to capture the coefficient indices, and the underlying trend of cepstral coefficients primarily governed by overall structural characteristics. The multi-head attention mechanism enables computationally efficient parallel analysis of interdependencies among coefficients, facilitating the development of a lightweight network. The effectiveness and superiority of the method have been validated using both simulated and experimental structural data.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"306 ","pages":"Article 107592"},"PeriodicalIF":4.4,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718511","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":"Conforming embedded isogeometric analysis for B-Rep CAD models with strong imposition of Dirichlet boundary conditions using trivariate B++ splines","authors":"Xuefeng Zhu ,&nbsp;Guangwu Ren ,&nbsp;Xiangkui Zhang ,&nbsp;Chunhui Yang ,&nbsp;An Xi ,&nbsp;Ping Hu ,&nbsp;Zheng-Dong Ma","doi":"10.1016/j.compstruc.2024.107586","DOIUrl":"10.1016/j.compstruc.2024.107586","url":null,"abstract":"<div><div>Strong imposition of Dirichlet boundary conditions for immersed finite element methods or immersed isogeometric methods remains a challenge. To address this issue, this paper presents a 3D conforming embedded isogeometric method for Boundary-Represented (B-Rep) solid CAD models by generalizing our bivariate B++ splines to trivariate B++ Splines. The proposed method can convert a B-Rep model into a trivariate B++ spline solid patch with body-fitted boundary representation while retaining key features of B-rep models, such as sharp points, sharp edges, and holes. The basis functions of the trivariate B++ spline solid patch satisfy the Kronecker delta property, which implies that we can strongly impose Dirichlet boundary conditions on B-Rep models without the necessity of Nitsche's method. The presented method can be viewed as a parameterization method that inherits the advantages of volumetric parameterization methods in that the basis functions of a reconstructed geometry satisfy the Galerkin method. In addition, compared with T-splines, the proposed method does not generate the extraordinary point and can achieve optimal convergence rate. Several numerical examples are used to demonstrate the reliability of the presented method.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107586"},"PeriodicalIF":4.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702689","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":"New implicit time integration schemes for structural dynamics combining high frequency damping and high second order accuracy","authors":"Eman Alhayki,&nbsp;Wulf G. Dettmer","doi":"10.1016/j.compstruc.2024.107587","DOIUrl":"10.1016/j.compstruc.2024.107587","url":null,"abstract":"<div><div>The time integration schemes, GA-23 and GA-234, recently proposed by the authors for first order problems, are extended to solve second-order problems in structural dynamics. The resulting methods maintain unconditional stability and user-controlled high-frequency damping. They offer improved accuracy and exhibit less numerical damping in the low-frequency regime, outperforming the well-known generalised-<em>α</em> method. When the high-frequency damping is maximised the new schemes can be cast in the format of backward difference formulae, offering more accurate alternatives to the standard second order formula. The effectiveness of the new time integration schemes is validated through a number of numerical examples, including a linear elastic cantilever beam, a nonlinear spring pendulum, and wave propagation on a string.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107587"},"PeriodicalIF":4.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702691","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":"Synergistic approach: Peridynamics and machine learning regression for efficient pitting corrosion simulation","authors":"J. Ramesh Babu,&nbsp;S. Gopalakrishnan","doi":"10.1016/j.compstruc.2024.107588","DOIUrl":"10.1016/j.compstruc.2024.107588","url":null,"abstract":"<div><div>Corrosion-induced material deterioration poses a pervasive threat to structural integrity, necessitating an in-depth understanding of its intricate behaviors. Pitting corrosion, a critical concern in this context, accelerates the degradation of materials. The limitations of conventional models arise from their neglect of the subsurface electrode boundary layer dynamics during the dissolution process. In this study, we present a novel approach that combines Peridynamics (PD) diffusion framework with machine learning (ML) techniques to develop an efficient predictive model and computational efficiency. The proposed hybrid PD-ML model leverages the non-local effects inherent to Peridynamics and the pattern recognition capabilities of machine learning. It establishes an analytical connection between the concentration value at a specific material point and the concentrations exhibited by related constituents within its spatial horizon, considering the external mass flux applied. The adaptability of the model is achieved through the utilization of weighted regression coefficients, determined via multivariate linear regression. Validation against experiments and conventional PD model demonstrates the model's precision and efficiency using diverse micro-diffusivity scenarios. For 1D uniform and 2D pitting corrosion cases, our hybrid model yields precise concentration predictions while showcasing a remarkable improvement in computational speed compared to conventional approaches. Specifically, the hybrid model achieves an impressive speedup, approximately 4 times faster per time step and 2.5 times faster overall simulation. The study presents a promising tool for predicting corrosion-induced material deterioration in practical systems, offering accuracy, efficiency, and potential for broader applications.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107588"},"PeriodicalIF":4.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702690","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 formulation of macro-element based modelling – Application to single-lap bonded joints","authors":"Sébastien Schwartz,&nbsp;Éric Paroissien,&nbsp;Frédéric Lachaud","doi":"10.1016/j.compstruc.2024.107589","DOIUrl":"10.1016/j.compstruc.2024.107589","url":null,"abstract":"<div><div>An extended formulation of the macro-element (ME) based models, representing for both adherends and adhesive along the entire overlap in only one four-node element, is presented. Compared to earlier modelling, continuum ME (CME) and discrete ME (DME) based models, the adherend parts are also modelled as plane continuum media, for which high order displacement fields are freely supposed. Both extended CME (ECME) and extended DME (EDME) based modelling can have their displacement field orders of each continuum layer be set individually, and can be enriched using springs for interfaces or boundary conditions modelling, allowing the stresses to vanish at the free edges. The methodology and formulation of the stiffness matrix for both the adherend without adhesive and the bonded overlap is presented. The assessment is performed for a single-lap joint geometry by comparison results from a plane strain finite element (FE) model with extended ME-based models. Good agreements are shown for both thin and thick adhesive case studies.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107589"},"PeriodicalIF":4.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702688","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":"Prediction of nonlinear dynamic responses and generation of seismic fragility curves for steel moment frames using boosting machine learning techniques","authors":"Farzaneh Zareian ,&nbsp;Mehdi Banazadeh ,&nbsp;Mohammad Sajjad Zareian","doi":"10.1016/j.compstruc.2024.107580","DOIUrl":"10.1016/j.compstruc.2024.107580","url":null,"abstract":"<div><div>The main objective of this paper is to develop machine learning (ML) models for predicting the seismic responses of steel moment frames. For this purpose, four boosting ML techniques-gradient boosting, XGBoost, LightGBM, and CatBoost-were developed in Python. To create an inclusive dataset, 92,400 nonlinear time-history analyses were performed on 1,848 steel moment frames under 50 earthquakes using OpenSeesPy. Geometric configurations, structural properties, and ground motion intensity measures were considered as the inputs for the models. The outputs included maximum global drift ratio (MGDR), maximum interstory drift ratio (MIDR), base shear coefficient (BSC), and maximum floor acceleration (MFA). The study also investigated the effectiveness of the ML models in estimating fragility curves for an 8-story steel frame at different performance levels. Finally, a web application was developed to facilitate the estimation of the peak dynamic responses for steel moment frames. The results show that the LightGBM and CatBoost models demonstrate superior predictive performance, with coefficient of determinations (R²) higher than 0.925. Furthermore, the LightGBM models can estimate the fragility curves with minimal errors (e.g., the relative errors in the median values of the predicted curves are less than 10%).</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107580"},"PeriodicalIF":4.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673350","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":"Bearing capacity analysis of RC slabs under cyclic loads: Dual numerical approaches","authors":"Phuc L.H. Ho ,&nbsp;Canh V. Le ,&nbsp;Dung T. Tran ,&nbsp;Phuong H. Nguyen ,&nbsp;Jurng-Jae Yee","doi":"10.1016/j.compstruc.2024.107585","DOIUrl":"10.1016/j.compstruc.2024.107585","url":null,"abstract":"<div><div>Shakedown analysis is a powerful and efficient tool for calculating the safety factors of structures under variable and repeated external quasi-static loads, that can prevent structures from incremental and alternative plasticity collapses. RC slabs in practical engineering applications are usually under long-tern variable and cyclic loads, but their fatigue behavior was rarely reported in the literature, particularly for those governed by the Nielsen yield condition. In this paper, dual static and kinematic shakedown formulations based on displacement-finite elements and conic programming are developed. The resulting optimization problems, characterized by a huge number of variables, are effectively solved. A wide range of practical RC slabs with diverse geometries, loading and boundary conditions are investigated, precisely capturing the collapse modes in terms localized plastic dissipation energy and presenting moment distribution at fatigue state. Strengthening strategies are performed in regions with localized plastic dissipation energy, showing that the load-bearing capacity of such slabs increases significantly while incremental and alternative collapse modes are prevented.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":"305 ","pages":"Article 107585"},"PeriodicalIF":4.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651386","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}