Engineering Analysis with Boundary Elements最新文献

{"title":"An improved high-precision polyhedron SBFEM with combinatorial interpolation strategies","authors":"","doi":"10.1016/j.enganabound.2024.105991","DOIUrl":"10.1016/j.enganabound.2024.105991","url":null,"abstract":"<div><div>Computational accuracy and solution efficiency are crucial indicators for evaluating the performance of finite element numerical algorithms, and the corresponding improvements in these areas are the motivation for the development of computational science. In this paper, a flexible and high-precision polyhedron algorithm is proposed in conjunction with SBFEM and the triangle/quadrilateral interpolation functions. The main content can be summarized as follows: The construction equations for a mixed-order polyhedron element are derived, meanwhile, a generalized procedural framework is designed for multi-performance applications, including automatic elements type identification, coupled solutions, and dynamic storage, and the integrated development is completed based on self-developed software GEODYNA. The correctness, convergence and practicability of the proposed method are demonstrated through several examples in different dimensions. The results show that the proposed method obtains results with an error of &lt;3 % compared to theoretical solutions and the fine numerical solutions, while significantly reducing computational costs; Besides, the proposed method overcomes the limitations of conventional methods on mesh shape and can be seamlessly integrated with octree algorithms, which offers a powerful technical means for the efficient and high-precision analyses of bending deformation and stress concentration problems. It is foreseeable that a good application potential in high-precision structural analysis would be revealed.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424515","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 multiple scattering effect of elastic waves propagation in an inhomogeneous medium","authors":"","doi":"10.1016/j.enganabound.2024.105983","DOIUrl":"10.1016/j.enganabound.2024.105983","url":null,"abstract":"<div><div>Unraveling the elastic wave propagating in an inhomogeneous medium is critical from both scientific and engineering viewpoints. Here, we propose and validate a double defects model based on unified mechanics framework to study the multiple scattering effect induced by the interaction between elastic waves and defects. The governing equations describing the dispersion and attenuation in frequency space are derived. In order to describe the multiple scattering effect, the Green's function method is employed together with the discrete boundary element method to establish the relation of macroscopic defect density and microscopic defect structure. The results show that the multiple scattering effect originates from the interaction between adjacent defects, and the limit of the multiple scattering (strong interaction) is approximately 6 times the characteristic length of the defect, namely the affected area of a single defect. Due to the stronger interaction, wave velocity decays more seriously for higher defects density than those in the lower density, and there exists no strong coupling between multi-scattering effect and multi-scale effect. The present work provides an efficient way to understand the multi-scattering effect of elastic waves in an inhomogeneous medium.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424518","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":"Machine learning applied to estate pricing for residential rentals in dynamic urban markets—The case of São Paulo city","authors":"","doi":"10.1016/j.enganabound.2024.105988","DOIUrl":"10.1016/j.enganabound.2024.105988","url":null,"abstract":"<div><div>This study conducts a comprehensive investigation into real estate rental pricing in São Paulo city, employing an innovative approach that combines advanced machine learning techniques with geospatial and natural language processing (NLP) analyses. The research analyzed a robust dataset comprising 47,243 rental listings, gathered through web scraping techniques. Following a rigorous data cleaning and preprocessing procedure, the study focused on 35,486 instances, incorporating a variety of variables that go beyond conventional metrics, including textual descriptions and geographic information, enriching the analysis and market understanding. Several regression models were implemented and compared, including linear approaches, Support Vector Machines, and ensemble methods such as Gradient Boosting, LightGBM, and XGBoost. The Blending model, which integrates multiple modeling techniques, stood out as the most accurate, achieving a Root Mean Squared Logarithmic Error (RMSLE) of 0.2923 on the test set. This result emphasizes the superiority of hybrid modeling strategies in complex pricing tasks. The findings of this study have significant practical implications. They provide landlords and tenants with a powerful data-driven tool for informed decision-making, reflecting the nuances and complexity of São Paulo’s real estate market. The practical implementation of the model in an interactive web application not only demonstrates its utility in the real-world scenario but also serves as a model for future applications in real estate analysis. This work contributes to mitigating the waste of time and energy when it comes to searching for and pricing residential rentals in a large city, through the use of machine learning that shows its power and potential in accurately estimating rental prices in dynamic urban markets, allowing that more assertive and economical decisions can be taken within a social-sustainable-technological perspective.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424516","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 reduced variational multiscale element free Galerkin method for three-dimensional steady incompressible Stokes and Navier–Stokes equations","authors":"","doi":"10.1016/j.enganabound.2024.105984","DOIUrl":"10.1016/j.enganabound.2024.105984","url":null,"abstract":"<div><div>In the paper, we extend the reduced variational multiscale element free Galerkin (RVMEFG) method to solve the three-dimensional steady incompressible Stokes and Navier–Stokes equations. This method is simplified based on the three-dimensional variational multiscale element free method (VMEFG), which the standard Galerkin discretization is used to momentum conservation equation and the variational multiscale method is used to mass conservation equation. The RVMEFG method inherits the advantages of the VMEFG method, which allows equal linear basis approximation of both velocity and pressure and avoids the Ladyzhenskaya–Babuška–Breezi (LBB) condition. Meanwhile, it can naturally generate the stabilization matrix. Furthermore, compared to the VMEFG method, the RVMEFG method can save computational cost. To verify the numerical stability, computational accuracy and efficiency of the method, five numerical problems are tested, and compared with the exact solution, VMEFG solution. It is shown that the RVMEFG method can avoid numerical oscillations and have higher computational efficiency which can save computational time. Meanwhile, it can guarantee the numerical accuracy for the three-dimensional steady incompressible Stokes and Navier–Stokes problems.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424513","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 new isogeometric boundary element method to analyze two-dimensional potential and elasticity problems","authors":"","doi":"10.1016/j.enganabound.2024.105986","DOIUrl":"10.1016/j.enganabound.2024.105986","url":null,"abstract":"<div><div>To reduce the impact of inhomogeneous boundary conditions on computational accuracy and the impact of redundant geometry refinement on computational efficiency in traditional isogeometric boundary element methods (IGABEM), a new IGABEM that introduces geometry-independent field approximation (GIFT) is proposed and applied to 2D potential and elasticity problems. Unlike in IGABEM, element nodes are located on the boundary, which facilitates the precise application of boundary conditions on nodes to improve computational accuracy. The constructed element features multiple inner nodes, allowing for the use of fewer elements in solving problems, which is beneficial for reducing redundancy and improving the computational efficiency of IGABEM. First, the geometrically precise BEM element is constructed using non-uniform rational B-splines (NURBS) to describe the geometry, while the field is approximated using B-spline interpolation and a transformation matrix. Second, the calculation formats of problems are derived by using parameter mapping. Third, the calculation of variables at boundary points is performed on the element through the relationship between variables. The subsequent processing is like the BEM. Finally, several numerical examples are discussed. It can be concluded from examples that the proposed method can obtain a high-precision solution and reduce computation costs.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424519","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 boundary-type algorithm based on the discrete ordinates for neutron transport equation","authors":"","doi":"10.1016/j.enganabound.2024.105981","DOIUrl":"10.1016/j.enganabound.2024.105981","url":null,"abstract":"<div><div>The spatial distribution of neutron flux in the core of a nuclear reactor plays a crucial role in ensuring nuclear safety. It can be determined by solving the neutron transport equation, where computational resource consumption is gradually receiving more attention, especially in problems with multiple reflective boundary conditions. It is common practice to assume initial boundary values in one angular direction to obtain a global solution, and then use reflective boundary conditions to solve for the other directions, iterating until convergence. However, this approach has the drawback of requiring the global solution, and each iteration necessitates storing the neutron flux values, consuming time and storage space. In order to address this issue, this paper proposes a precise and efficient boundary-type method, the Half Boundary Method (HBM). This method establishes relationships between adjacent node values through integration and mathematical deduction, ultimately obtaining the relationship among any node and the boundary values in any direction. As a result, iteration is only required for boundary values, reducing the iteration amount and thus saving time and storage space. Using the discrete ordinate (S_N) method for angular discretization and HBM for spatial discretization, this paper solved the steady-state neutron transport equation for two-dimensional systems modeled with Cartesian geometry. The method is validated using several benchmark problems, including the 2D ISSA benchmark, the 2D mono-group <em>k</em>-eigenvalue problem and BWR rod bundle test problem. All of these problems demonstrate good results and effectively reduced computational time.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424517","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":"Localized space-time Trefftz method for diffusion equations in complex domains","authors":"","doi":"10.1016/j.enganabound.2024.105977","DOIUrl":"10.1016/j.enganabound.2024.105977","url":null,"abstract":"<div><div>This paper introduces an advanced localized space-time Trefftz method tackling boundary value predicaments within complex two-dimensional domains governed by diffusion equations. In contrast to the widespread space-time collocation Trefftz method, which typically produces dense and ill-conditioned matrices, the proposed strategy employs a localized collocation scheme to remove these constraints. In particular, this is beneficial in multi-connected configurations or when dealing with significant variations in field values. To the best of our knowledge, this is the first space-time collocation Trefftz method adaptation, which is referred to as the localized space-time Trefftz method in this paper. The latter combines the space-time collocation Trefftz method principles, which allows to eliminate the need for mesh and numerical quadrature in its application. The localized space-time Trefftz method represents each interior node expressed as a linear blend of its immediate neighbors, while the space-time collocation Trefftz method applies numerical techniques within distinct subdomains. A sparse system of linear algebraic equations with internal points satisfying the governing equation, and boundary points satisfying the boundary conditions, allows to obtain numerical solutions using matrix systems. The localized space-time Trefftz method retains the easy-to-use properties and mesh-free structure of the space-time collocation Trefftz method, and it mitigates its ill-conditioning characteristics. Due to the localization principle and the consideration of overlapping subdomains, the solutions in the proposed localized space-time Trefftz method are more simply and compactly expressed compared with those in the space-time collocation Trefftz method, especially when dealing with multiply-connected domains. Numerical examples for simply-connected and multiply-connected domains are then provided to demonstrate the high precision and simplicity of the proposed localized space-time Trefftz method. The obtained results show that the latter has very high accuracy in solving two-dimensional diffusion problems. Compared with the traditional space-time collocation Trefftz method, the proposed mesh-free strategy yields solutions with higher precision while significantly reducing the instability.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424478","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":"An efficient computational method for solving the fractional form of the European option price PDE with transaction cost under the fractional Heston model","authors":"","doi":"10.1016/j.enganabound.2024.105972","DOIUrl":"10.1016/j.enganabound.2024.105972","url":null,"abstract":"<div><div>This paper introduces a new method for precise option pricing analysis by utilizing the fractional form of the option price partial differential equation (PDE) and implementing a collocation technique based on the first Fermat polynomial sequence. The key innovation of this study is the exploration of the fractional formulation of European option pricing within the context of the fractional Heston model, which employs a collocation scheme utilizing Fermat polynomials to generate operational matrices characterized by numerous zeros, thereby enhancing computational efficiency. To achieve this, we first derive the option price PDE and convert it to its fractional form in the Caputo sense. We then solve the fractional PDE using fractional Fermat functions, expressing the solution as a series of multivariate Fermat functions with unknown coefficients. Following this, we compute the operational matrices for the Caputo fractional derivative and related partial derivatives, demonstrating how this computational framework transforms the primary problem into a nonlinear system of equations. Additionally, we conduct a convergence analysis of the collocation method. We conclude by presenting several numerical examples that illustrate the applicability and effectiveness of the proposed method, with its robust theoretical foundations and successful numerical tests indicating significant potential for practical applications in finance.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424520","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":"Three-dimensional mesoscale analysis of the dynamic tensile behavior of concrete with heterogeneous mesostructure","authors":"","doi":"10.1016/j.enganabound.2024.105982","DOIUrl":"10.1016/j.enganabound.2024.105982","url":null,"abstract":"<div><div>This paper investigates the dynamic tensile behavior of concrete under high strain rates. An optimized random concrete mesostructure generation procedure is established using the 3<em>D</em> entrance block (3<em>D E</em>(<em>A, B</em>)) algorithm to account for the intrinsic material heterogeneity. This approach avoids repetitive and complicated polyhedral aggregate overlapping checks in traditional methods, resulting in a highly efficient aggregate packing process. The nucleation, propagation, and coalescence of cracks are captured by a properly developed rate-dependent cohesive constitutive law. The mesoscale model is validated through comparison with experimental results. The crack evolution in the concrete under dynamic direct tensile loading conditions is explicitly presented, and the effects of the aggregate volume fraction and ITZ properties on the dynamic tensile strength enhancements are studied. The results indicate that material heterogeneity significantly influences the fracturing process and damage distribution. The dynamic tensile strength of concrete exhibits a two-strain rate regime dependence on the aggregate volume fraction concerning the strain rate. The influence of the mechanical properties of the ITZ on the dynamic tensile strength of concrete increases with the increasing strain rate.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424479","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":"Shape optimization with level set-based method using a reaction diffusion equation for 2D sound barrier","authors":"","doi":"10.1016/j.enganabound.2024.105978","DOIUrl":"10.1016/j.enganabound.2024.105978","url":null,"abstract":"<div><div>A level set-based method using a reaction diffusion equation is applied for optimization problems of two dimensional (2D) sound barriers. The level set method is employed to implicitly represent the sound barrier structure, which distinguishes the material and void domains by the value of the level set function. The boundary element method is employed to solve acoustic problems governed by Helmholtz equation. Topological derivatives are computed by the boundary integral equation combined with the adjoint variable method. The distribution of level set function is iteratively updated based on the reaction diffusion equation to find the optimal structure. For the existent floating scatterers in the optimization process and the sharp and narrow parts on the surface of the sound barrier, we propose a filtering algorithm to remove floating scatterers and develop a method to achieve a smooth surface of the sound barrier. The shape optimization of sound barriers is achieved using these techniques, integrating the level set-based topology optimization method. Numerical tests are provided to demonstrate the validity and effectiveness of the proposed methods.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424512","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}