Engineering Analysis with Boundary Elements最新文献

{"title":"Shaping quasi-transparent nanotubes into Maximally strong EM scatterers","authors":"Nurkeldi Iznat ,&nbsp;Madeniyet Bespayev ,&nbsp;Yerassyl Turarov ,&nbsp;Constantinos Valagiannopoulos ,&nbsp;Konstantinos Kostas","doi":"10.1016/j.enganabound.2025.106153","DOIUrl":"10.1016/j.enganabound.2025.106153","url":null,"abstract":"<div><div>The problem of enhancing the electromagnetic (EM) scattering for almost transparent nanotubes via shape modification of their cross section, is studied in this work. An isogeometric analysis approach, in a boundary element method setting, is employed to evaluate the local electric field, which is expressed in terms of the exact same basis functions utilized in the geometric representation of the cylinder boundary. In this way, the overall scattering power becomes computable via proper integration of the far field magnitude around the nanotube and shape optimization can be directly performed with the aim of maximizing the scattering enhancement compared to an equiareal circular nanotube. The optimization framework uses: (i) a hybrid approach combining global optimizers with gradient-based local algorithms for accurately determining the shape at the final stages, (ii) a series of parametric models generating valid non-self-intersecting nanotube shapes, and (iii) an isogeometric-enabled boundary element method solver approximating the value of the electric field with high accuracy. The optimized nanotube shapes give much higher total scattering response than their circular counterparts. In a wide range of operating conditions (such as nanotube’s electric conductivity or cross section area), the optimized shapes assumed a distinct spiky shape which was further studied with respect to the direction of excitation. Apart from boosting scattering for quasi-transparent nanotubes, the developed methodology can be adapted to solve the inverse problem, namely, determining the nanotube shape from its scattering signal, as well as extended to address similar problems with finite arrays of nanotubes comprising EM metasurfaces.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106153"},"PeriodicalIF":4.2,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143421919","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 NURBS-enhanced semi-analytical method for nonlinear liquid sloshing analysis in liquid storage structures with various baffles","authors":"Quansheng Zang ,&nbsp;Yanhui Zhong ,&nbsp;Wenbin Ye ,&nbsp;Jun Liu ,&nbsp;Bin Li ,&nbsp;Fan Yang ,&nbsp;Songtao Li","doi":"10.1016/j.enganabound.2025.106155","DOIUrl":"10.1016/j.enganabound.2025.106155","url":null,"abstract":"<div><div>Within the framework of scaled boundary finite element method (SBFEM) and inspired by isogeometric analysis (IGA), the NURBS-enhanced semi-analytical method, referred to as the scaled boundary isogeometric analysis (SBIGA), is extended for solving nonlinear liquid sloshing analysis in storage structures. This method leverages the advantages of Non-Uniform Rational B-Splines (NURBS), offering a highly efficient and accurate solution. NURBS provides high-order continuity, making it particularly suitable for capturing the smoothness of free liquid surfaces in sloshing phenomena. Compared to traditional Lagrangian elements, the proposed approach efficiently utilizes control points, enabling accurate geometric representation with fewer degrees of freedom. A semi-Lagrangian algorithm establishes a global fixed coordinate system and a local system moving with the structure, enabling flexible mesh updating and efficient computation. Based on potential flow theory, the SBIGA equations for nonlinear liquid sloshing are derived using the weighted residual method, with dual variables introduced. The eigenfunction expansion method solves the equations, and the fourth-order Runge–Kutta method is applied for time integration. This approach combines the strengths of SBFEM and IGA, featuring boundary-only discretization, radial analytical solutions, and precise geometric boundary representation. Meanwhile, the present SBIGA does not require fundamental solutions as in traditional methods, nor does it require handling corner singularities or singular integrals as in boundary element methods. Numerical examples validate the accuracy of the present model, followed by analyses of the sloshing reduction effects of horizontal and vertical baffles in rectangular liquid storage structures. Finally, a U-shaped aqueduct under seismic loading is examined to evaluate the effectiveness of baffles in reducing sloshing responses in complex structures under seismic conditions.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106155"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422010","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 study on different implementations of Neumann boundary conditions in the meshless RBF-FD method for the phase-field modelling of dendrite growth","authors":"Tadej Dobravec ,&nbsp;Boštjan Mavrič ,&nbsp;Božidar Šarler","doi":"10.1016/j.enganabound.2025.106154","DOIUrl":"10.1016/j.enganabound.2025.106154","url":null,"abstract":"<div><div>This paper studies and assesses different Neumann boundary conditions (BC) implementations in the radial basis function generated finite difference (RBF-FD) method. We analyse four BC implementations by solving a phase-field model for single dendrite growth in supercooled pure melts. In the first BC implementation, the BC are satisfied when constructing interpolation problems in the local support domains near the boundary. In the second one, the BC are satisfied by solving an additional system of linear equations for the field values in the boundary nodes. In the third one, we add a layer of ghost nodes to the boundary nodes; the BC are satisfied by solving an additional system of linear equations for the field values in the ghost nodes. The fourth BC implementation uses the same node distribution as the third one; since we are dealing with the symmetric BC, we set the values in the ghost nodes by direct mirroring. We analyse the influence of the size of a local support domain and the type of node distribution (regular/scattered) on the accuracy. We show that using ghost nodes is recommended to consider Neumann BC in the RBF-FD method accurately when solving phase-field models for dendritic growth.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106154"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403093","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":"S-PEEC-DI: Surface Partial Element Equivalent Circuit method with decoupling integrals","authors":"Maria De Lauretis ,&nbsp;Elena Haller ,&nbsp;Daniele Romano ,&nbsp;Giulio Antonini ,&nbsp;Jonas Ekman ,&nbsp;Ivana Kovačević-Badstübner ,&nbsp;Ulrike Grossner","doi":"10.1016/j.enganabound.2025.106152","DOIUrl":"10.1016/j.enganabound.2025.106152","url":null,"abstract":"<div><div>In computational electromagnetics, numerical methods are generally optimized for triangular or tetrahedral meshes. However, typical objects of general interest in electronics, such as diode packages or antennas, have a Manhattan-type geometry that can be modeled with orthogonal and rectangular meshes. The advantage of orthogonal meshes is that they allow analytic solutions of the integral equations. In this work, we optimize the decoupling of the integrals used in the Surface formulation of the Partial Element Equivalent Circuit (S-PEEC) method for rectangular meshes. We consider a previously proposed decoupling strategy, and we lighten the underlying math by generalizing it. The new method shows improved accuracy and computational time because the number of decoupling integrals is generally reduced. The new S-PEEC method with decoupling integrals is named S-PEEC-DI. The S-PEEC-DI method is tested on a realistic diode package and compared with the volumetric PEEC (V-PEEC) and two well-known commercial solvers.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106152"},"PeriodicalIF":4.2,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402998","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":"Optimizing chatbot responsiveness: Automated history context selector via three-way decision for multi-turn dialogue Large Language Models","authors":"Weicheng Wang ,&nbsp;Xiaoliang Chen ,&nbsp;Duoqian Miao ,&nbsp;Hongyun Zhang ,&nbsp;Xiaolin Qin ,&nbsp;Xu Gu ,&nbsp;Peng Lu","doi":"10.1016/j.enganabound.2025.106150","DOIUrl":"10.1016/j.enganabound.2025.106150","url":null,"abstract":"<div><div>Enhancing the efficiency of chat models in multi-turn dialogue systems is a critical challenge in Artificial Intelligence. Multi-turn dialogues often span diverse topics, with irrelevant dialogue turns frequently degrading the quality of the model’s responses. This study addresses this challenge by proposing a novel method for the automated identification and selection of contextually relevant dialogue turns. Our approach introduces an Automated Relevance Labeling Pipeline, which leverages three-way decision and the K-Nearest Neighbors algorithm to automatically assign relevance labels by calculating the distance between dialogue turns and final responses. A Relevance Selector is trained on these labels, enabling it to accurately detect and prioritize relevant dialogue turns from the conversation history. The proposed method has been tested across various datasets demonstrating significant performance improvements over existing approaches that indiscriminately expand the entire conversation history. Notably, the integration of this method into existing chat models resulted in an increase in Recall rates by 4%–6% and a marked reduction in perplexity, approaching the accuracy of manually annotated data. The method’s zero-shot learning capabilities further underscore its generalizability applying to diverse conversational contexts without requiring additional fine-tuning. These results highlight the method’s potential to significantly enhance the performance of multi-turn dialogue systems.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106150"},"PeriodicalIF":4.2,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387550","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":"Linearly scalable fast direct solver based on proxy surface method for two-dimensional elastic wave scattering by cavity","authors":"Yasuhiro Matsumoto ,&nbsp;Taizo Maruyama","doi":"10.1016/j.enganabound.2025.106148","DOIUrl":"10.1016/j.enganabound.2025.106148","url":null,"abstract":"<div><div>This paper proposes an <span><math><mrow><mi>O</mi><mrow><mo>(</mo><mi>N</mi><mo>)</mo></mrow></mrow></math></span> fast direct solver for two-dimensional elastic wave scattering problems. The proxy surface method is extended to elastodynamics to obtain shared coefficients for low-rank approximations from discretized integral operators. The proposed method is a variant of the Martinsson–Rokhlin–type fast direct solver. Our variant avoids the explicit computation of the inverse of the coefficient matrix, thereby reducing the required number of matrix–matrix multiplications. Numerical experiments demonstrate that the proposed solver has a complexity of <span><math><mrow><mi>O</mi><mrow><mo>(</mo><mi>N</mi><mo>)</mo></mrow></mrow></math></span> in the low-frequency range and has a highly parallel computation efficiency with a strong scaling efficiency of 70%. Furthermore, multiple right-hand sides can be solved efficiently; specifically, when solving problems with 180 right-hand side vectors, the processing time per vector from the second vector onward was approximately 28,900 times faster than that for the first vector. This is a key advantage of fast direct methods.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106148"},"PeriodicalIF":4.2,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387549","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 supervised learning algorithm to simulate tumor growth: Cahn–Hilliard model on surfaces","authors":"Mojtaba Torkian ,&nbsp;Mostafa Abbaszadeh ,&nbsp;Seyed Majid Alavi ,&nbsp;Majid Haghverdi","doi":"10.1016/j.enganabound.2025.106132","DOIUrl":"10.1016/j.enganabound.2025.106132","url":null,"abstract":"<div><div>The current work concerns to introduce a new numerical solution based upon a supervised learning algorithm with the shape functions of reproducing kernel particle method (RKPM). In the developed technique a least-squares support vector regression is extended for the numerical solution of the Cahn–Hilliard (CH) model in two- and three-dimensional domains. First, the time derivative is approximated by a BDF2 algorithm to get a semi-discrete scheme. Then, the local RKPM-differential quadrature (LRKPM-DQ) is employed to build the differential matrices. Finally, the least-squares support vector regression idea is used to drive the numerical solution. The proposed numerical procedure is applied for two-dimensional CH model and also it is examined for the main mathematical model on different surfaces. The numerical results confirm the ability and efficiency of the introduced numerical formulation.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106132"},"PeriodicalIF":4.2,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143387490","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 numerical manifold method for piezoelectric materials with hole flaws under electro-mechanical loadings","authors":"C.L. Li,&nbsp;D.L. Guo,&nbsp;H.H. Zhang","doi":"10.1016/j.enganabound.2025.106149","DOIUrl":"10.1016/j.enganabound.2025.106149","url":null,"abstract":"<div><div>Piezoelectric intelligent materials are pivotal in a multitude of fields. In this work, the numerical manifold method (NMM) is developed to model piezoelectric solids with arbitrarily shaped cavities. The superiority of this method roots in its dual-cover systems, namely, the mathematical and physical covers, which enable the NMM to straightforwardly discretize physical domain with non-conforming mathematical covers. The governing equations and boundary conditions are introduced, upon which the NMM global discrete equations are formulated via the weighted residual method and the NMM physical field approximations. Several numerical examples with increasing complexity are conducted to verify the proposed approach. Furthermore, the impacts of hole configurations, polarization directions and loading conditions on the electro-mechanical behavior of perforated piezoelectric materials are also investigated.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106149"},"PeriodicalIF":4.2,"publicationDate":"2025-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378788","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 RBF-FD method for solving the time-fractional viscoelastic wave propagation in irregular domains","authors":"Feng Wang,&nbsp;Yan Zhu,&nbsp;Sihao Jia,&nbsp;Xu Guo","doi":"10.1016/j.enganabound.2025.106121","DOIUrl":"10.1016/j.enganabound.2025.106121","url":null,"abstract":"<div><div>The time-fractional viscoelastic wave equation plays a crucial role in geophysical exploration by accurately modeling wave attenuation and velocity dispersion in Earth’s media. However, solving this equation is challenging due to the stress–strain relationship governed by the Caputo fractional derivative of small orders and the complexity of irregular surface topographies. The requirement for significant memory and computational resources when dealing with small fractional orders limits the efficiency of traditional methods. Conventional approaches, which rely on horizontal reference planes, fixed-step grids, and stair-step approximations for irregular surfaces, often lead to staircase scattering and reduced accuracy. To address these challenges, this study proposes a numerical algorithm based on the Radial Basis Function-Finite Difference (RBF-FD) method for simulating time-fractional viscoelastic waves in irregular domains. The meshless nature of the RBF-FD method allows for flexible node distribution, making it well-suited for complex interfaces. Additionally, a short-memory algorithm is implemented to efficiently solve the stress–strain relationship governed by the fractional derivative. Several numerical experiments are presented to validate the accuracy and efficiency of the proposed scheme.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106121"},"PeriodicalIF":4.2,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372126","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":"Meshfree analysis of brain tumor growth under various treatment plans considering the mechanical stress effect","authors":"Amir Khosravifard,&nbsp;Ghazaleh Ansari","doi":"10.1016/j.enganabound.2025.106151","DOIUrl":"10.1016/j.enganabound.2025.106151","url":null,"abstract":"<div><div>Brain tumors are among the deadliest types of cancer and the most challenging to treat. Predicting the growth behavior of tumors can help physicians choose the best treatment program. Herein, a numerical technique based on the meshless radial point interpolation methods is presented for simulating the growth of brain tumors under the effects of radiotherapy and chemotherapy. In this work, the stress field induced in the brain due to tumor growth and its effect on tumor diffusion is analyzed. In the meshfree method, to obtain the system of discrete equations, the weak-form of the coupled nonlinear system of governing equations is developed. Part of the simulations is based on clinical data obtained from other research; additionally, data found in the literature is used to validate the results. The effects of various conventional treatment programs, with and without considering the effect of the stress field in brain tissue, are analyzed and compared. Furthermore, the order of radiotherapy and chemotherapy treatments is investigated. It is shown that when the stress effect is considered, the points with maximum stress are where tumor growth is highest. After the cell density reaches its maximum value at these points, growth is transferred to the surrounding areas.</div></div>","PeriodicalId":51039,"journal":{"name":"Engineering Analysis with Boundary Elements","volume":"173 ","pages":"Article 106151"},"PeriodicalIF":4.2,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143348206","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}