Computers & Structures最新文献

{"title":"Influence of the vertical seismic component on the response of continuous RC bridges","authors":"","doi":"10.1016/j.compstruc.2024.107558","DOIUrl":"10.1016/j.compstruc.2024.107558","url":null,"abstract":"<div><div>This paper investigates the influence of vertical seismic accelerations on the seismic response of RC bridges through numerical simulations using an enhanced non-linear numerical model. Results confirm that the incorporation of vertical accelerations, either through actual records or scaled horizontal records, can considerably modify the seismic response and the collapse mechanism. In the case of actual vertical records, the vertical component significantly contributes to premature structural deterioration, intensifying demand and accelerating failure mechanisms. On the other hand, the study underscores the inadequacy of using scaled horizontal records to represent vertical accelerations, as suggested by some seismic codes, as it not only distorts seismic response evaluation but also alters failure modes. The analysis of vertical vibration reveals higher displacements, increasing flexural demand on the deck, and leading to a progressive loss of vertical support at the central column. The research establishes the need to accurately account for vertical seismic accelerations in bridge design evaluations, as their impact on structural response and failure mechanisms cannot be underestimated. The work highlights the importance of a highly detailed 3D numerical model in assessing traditional parameters and capturing complex collapse mechanisms arising from material and geometric nonlinearities.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420485","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 quadrilateral inverse plate element for real-time shape-sensing and structural health monitoring of thin plate structures","authors":"","doi":"10.1016/j.compstruc.2024.107551","DOIUrl":"10.1016/j.compstruc.2024.107551","url":null,"abstract":"<div><div>The inverse finite element method (iFEM) emerged as a powerful tool in shape-sensing and structural health monitoring (SHM) applications with distinct advantages over existing methodologies. In this study, a quadrilateral inverse-plate element is formulated via a sub-parametric approach using bi-linear and non-conforming cubic Hermite basis functions for engineering structures, which can be modeled as thin plates. Numerical validation involves dense and assumed sparse sensor arrangements for in-plane, out-of-plane, and mixed general loading conditions. iFEM analysis reveals efficient monotonic convergence to analytical and high-fidelity finite element reference solutions. After successful numerical validation, defect detection analysis is performed considering minute geometric discontinuities and structural stiffness reduction because of latent subsurface defects under tensile and transverse loading conditions. The inverse formulation successfully resolves the presence of simulated defects under a sparse sensor arrangement. The proposed inverse-plate element is accurate in the full-field reconstruction of shape-sensing profiles and reliable in defect identification and quantification in thin plate structures.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420483","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":"The Hellan–Herrmann–Johnson and TDNNS methods for linear and nonlinear shells","authors":"","doi":"10.1016/j.compstruc.2024.107543","DOIUrl":"10.1016/j.compstruc.2024.107543","url":null,"abstract":"<div><div>In this paper we extend the recently introduced mixed Hellan–Herrmann–Johnson (HHJ) method for nonlinear Koiter shells to nonlinear Naghdi shells by means of a hierarchical approach. The additional shearing degrees of freedom are discretized by <span><math><mi>H</mi><mo>(</mo><mrow><mi>curl</mi></mrow><mo>)</mo></math></span>-conforming Nédélec finite elements entailing a shear locking free method. By linearizing the models we obtain in the small strain regime linear Kirchhoff–Love and Reissner–Mindlin shell formulations, which reduce for plates to the originally proposed HHJ and TDNNS methods for Kirchhoff–Love and Reissner–Mindlin plates, respectively. By interpolating the membrane strains into the so-called Regge finite element space we obtain locking-free arbitrary order shell methods. Additionally, the methods can be directly applied to structures with kinks and branched shells. Several numerical examples and experiments are performed validating the excellent performance of the proposed shell elements.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420484","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":"Jacobi-Ritz method for dynamic analysis of functionally graded cylindrical shell with general boundary conditions based on FSDT","authors":"","doi":"10.1016/j.compstruc.2024.107552","DOIUrl":"10.1016/j.compstruc.2024.107552","url":null,"abstract":"<div><div>This study introduces the vibration behavior of uniform functionally graded (FG) cylindrical shells by Jacobi-Ritz method. The first-order shear deformation theory (FSDT) and domain decomposition method (DDM) are used to establish the theoretical model. The complex constraint of FG cylindrical shells is realized by using artificial springs. The Jacobi orthogonal polynomials combined with Fourier series can be expanded to denote the admissible displacement field of the structure. Finally, the Rayleigh-Ritz method has been adopted to solve the behavior of free vibration and forced vibration. The transient vibration behavior of FG cylindrical shells is solved in accordance with Newmark-<em>β</em> integration method. For verify the validity of Jacobi-Ritz method, the convergence study is carried out, and the calculation results of FG cylindrical shells with various influencing factors such as boundary conditions, material parameters, excitation load forms and geometric dimensions are given, and the FEM results and published literature are compared. The computation show that the method has high precision and can supply theoretical basis for vibration control of FG cylindrical shell. <span><span>This study introduces the vibration behavior of uniform functionally graded (FG) cylindrical shells by Jacobi-Ritz method. The first-order shear deformation theory (FSDT) and domain decomposition method (DDM) are used to establish the theoretical model. The complex constraint of FG cylindrical shells is realized by using artificial springs. The Jacobi orthogonal polynomials combined with<!--> </span><svg><path></path></svg></span>Fourier series can be expanded to denote the admissible displacement field of the structure. Finally, the Rayleigh-Ritz method has been adopted to solve the behavior of free vibration and forced vibration. The transient vibration behavior of FG cylindrical shells is solved in accordance with Newmark-<em>β</em> <!-->integration method. For verify the validity of Jacobi-Ritz method, the convergence study is carried out, and the calculation results of FG cylindrical shells with various influencing factors such as boundary conditions, material parameters, excitation load forms and geometric dimensions are given, and the FEM results and published literature are compared. The computation show that the method has high precision and can supply theoretical basis for vibration control of FG cylindrical shell.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323435","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 simultaneous shape and topology optimization approach of shell structures based on isogeometric analysis and density distribution field","authors":"","doi":"10.1016/j.compstruc.2024.107550","DOIUrl":"10.1016/j.compstruc.2024.107550","url":null,"abstract":"<div><div>This paper presents a novel simultaneous shape and topology optimization approach of shell structures based on isogeometric analysis and density distribution field. In the optimization approach, Non-Uniform Rational B-Splines (NURBS) technology is utilized to describe the geometry and material distribution of the shell structures. The coordinates and densities of the NURBS control points are utilized as design variables to simultaneously optimize the shape and topology of shell structures. The proposed approach offers significant advantages, including ease of implementation, seamless integration with CAD models, high efficiency, and smooth, clear boundaries. Two representative examples are performed to demonstrate the effectiveness of the proposed approach. The optimized configurations are compared with other works and commercial software results.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323434","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":"Grammar-based generation of strut-and-tie models for designing reinforced concrete structures","authors":"","doi":"10.1016/j.compstruc.2024.107549","DOIUrl":"10.1016/j.compstruc.2024.107549","url":null,"abstract":"<div><div>Reinforced concrete structures featuring discontinuity regions are complex to design and often susceptible to errors linked to numerical analysis methods. For such structural design problems, strut-and-tie models offer a simple, intuitive and safe design method based on the lower bound theorem of plasticity. Although intuitive, the derivation of strut-and-tie models requires nonnegligible effort and a certain degree of expertise to navigate the highdimensional design space. The automated generation of strut-and-tie models is nontrivial with existing optimisation-based methods, which struggle with accounting for fabrication aspects or incorporating user adaptations.</div><div>This paper presents a novel grammar-based approach for generating practical strut-and-tie models by representing them as graphs and constructing a graph grammar. It consists of rules customised to consider engineering judgement, significantly reducing the dimensionality of the design space. The sequential application of such rules allows for human-computer interaction and aids engineers in decision-making, while being kept in the loop. Parsing four common design examples from the literature demonstrates the efficacy of this approach. The developed designs are more practical compared with existing optimisation-based suggestions. This interpretable grammar-based approach closely follows the intuitive decision-making process of practising structural engineers, which could be adapted to support further structural engineering design tasks.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319706","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 method for static analysis of multistage cyclic structure based on group theory and two-stage Guyan reduction","authors":"","doi":"10.1016/j.compstruc.2024.107548","DOIUrl":"10.1016/j.compstruc.2024.107548","url":null,"abstract":"<div><div>Considering the non-negligible multistage coupling effect of stages in multi-stage cyclic structure, such as bladed disk systems in aircraft turbo engines, a method is established for the static analysis of multistage cyclic structures. A special coordinate system is established based on the structural characteristics of the multistage cyclic structure. In this coordinate system, the sectors of a given disk have the same position; therefore, the stiffness matrices of any sector of the same disk are identical. Then, based on a two-stage Guyan reduction, the internal degrees of freedom (DOFs) of the disks are condensed and the number of DOFs corresponding to the full structure is reduced to that corresponding to the interdisk structures. Furthermore, group theory and the properties of the block circulant matrix are used to significantly reduce the computational cost of the two-stage Guyan reduction. Compared to the analysis of the full finite element model, the proposed method introduces no approximation. The main advantages of the proposed method are its high accuracy, high efficiency, and less demand on computational resources. Numerical examples demonstrate the accuracy and efficiency of the proposed method.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142314162","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":"Stabilization and improvement of the convergence of hybrid-Trefftz stress elements for plate bending analysis","authors":"","doi":"10.1016/j.compstruc.2024.107519","DOIUrl":"10.1016/j.compstruc.2024.107519","url":null,"abstract":"<div><div>The polynomial boundary basis usually applied in the implementation of hybrid-Trefftz stress elements for plate bending is extended to render its rate of convergence insensitive to the shear-to-bending stiffness ratio of the plate. The boundary basis is also extended to improve the accuracy of the element in the modelling of boundary layer effects and of singular stress fields caused by wedge effects. Numerical testing problems are selected to illustrate and validate the effect of the proposed extensions on the stabilization and improvement of finite element solutions. The solutions modelling boundary layer effects in Mindlin-Reissner plates are used to recover the equivalent shear and corner force concepts of the Kirchhoff plate bending model.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0045794924002487/pdfft?md5=1a34466f1902b9a08c3c30857fd81bc4&pid=1-s2.0-S0045794924002487-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311685","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":"Uncertainty quantification of acoustic metamaterial bandgaps with stochastic material properties and geometric defects","authors":"","doi":"10.1016/j.compstruc.2024.107511","DOIUrl":"10.1016/j.compstruc.2024.107511","url":null,"abstract":"<div><div>Acoustic metamaterials are a subject of increasing study and utility. Through designed combinations of geometries with material properties, acoustic metamaterials can be built to arbitrarily manipulate acoustic waves for various applications. Despite the theoretical advances in this field, however, acoustic metamaterials have seen limited penetration into industry and commercial use. This is largely due to the difficulty of manufacturing the intricate geometries that are integral to their function and the sensitivity of metamaterial designs to material batch variability and manufacturing defects. Capturing the effects of stochastic material properties and geometric defects requires empirical testing of manufactured samples, but this can quickly become prohibitively expensive with higher precision requirements or with an increasing number of input variables. This paper demonstrates how uncertainty quantification techniques, and more specifically the use of polynomial chaos expansions and spectral projections, can be used to greatly reduce sampling needs for characterizing acoustic metamaterial dispersion curves. With a novel method of encoding geometric defects in a 1D, interpretable, resolution-independent way, our uncertainty quantification approach allows for both stochastic material properties and geometric defects to be considered simultaneously. Two to three orders of magnitude sampling reductions down to <span><math><mo>∼</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>0</mn></mrow></msup></math></span> and <span><math><mo>∼</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>1</mn></mrow></msup></math></span> were achieved in 1D and 7D input space scenarios, respectively. Remarkably, this reduction in sampling was possible while preserving accurate output probability distributions of the metamaterial performance characteristics (bandgap size and location).</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311686","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":"On thermomechanical problems in a topology optimisation method based on non-uniform rational basis spline entities","authors":"","doi":"10.1016/j.compstruc.2024.107530","DOIUrl":"10.1016/j.compstruc.2024.107530","url":null,"abstract":"<div><div>This paper presents a new method to deal with thermomechanical topology optimisation (TO) problems based on a pseudo-density algorithm reformulated in the context of Non Uniform Rational Basis Spline (NURBS) entities. Specifically, a NURBS entity is used to represent the topological descriptor, providing an implicit filtering effect thanks to the local support propriety. The problem is formulated in the most general case of inhomogeneous Neumann-Dirichlet boundary conditions and design-dependent thermal sources and thermomechanical loads. In this context, a study on the combined effect of design-dependent heat sources, thermomechanical loads and applied forces and displacements on the optimal topologies is carried out. Furthermore, the influence of the penalisation schemes involved in the definition of the stiffness matrix, conductivity matrix, thermal loads and thermal sources on the optimised topology is investigated through a wide campaign of sensitivity analyses. Finally, sensitivity analyses are also conducted to investigate the influence of the integer parameters of the NURBS entity on the optimised solution. The effectiveness of the approach is tested on 2D and 3D benchmark problems.</div></div>","PeriodicalId":50626,"journal":{"name":"Computers & Structures","volume":null,"pages":null},"PeriodicalIF":4.4,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311687","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}