Applied Mathematical Modelling最新文献

{"title":"A coupled LBM-LES-DEM particle flow modeling for microfluidic chip and ultrasonic-based particle aggregation control method","authors":"Lin Li ,&nbsp;Pu Xu ,&nbsp;Qihan Li ,&nbsp;Runyuan Zheng ,&nbsp;Xiaoming Xu ,&nbsp;Jiafeng Wu ,&nbsp;Baiyan He ,&nbsp;Jiaji Bao ,&nbsp;Dapeng Tan","doi":"10.1016/j.apm.2025.116025","DOIUrl":"10.1016/j.apm.2025.116025","url":null,"abstract":"<div><div>Microfluidic chips present considerable potential in biomedical analysis and high-throughput cell separation, owing to their efficient and precise microscale flow control capabilities. In microscale channels, the highly nonlinear mechanics of vortex mixing and flow pattern evolution pose challenges to solid-liquid mass transfer modeling and particle cluster control. To address the above challenge, this paper proposes a two-phase particle flow modeling and ultrasonic-based particle aggregation control method for serpentine bionic microchannels in microfluidic chips. The particle flow dynamics model is established by coupling the lattice Boltzmann method (LBM) with the discrete element method (DEM), and integrating it with the large eddy simulation (LES) model. The LBM-LES-DEM model reveals the mixing and mass transfer mechanisms and particle distribution patterns in the serpentine channel under varying flow and particle conditions. Finally, utilizing an ultrasonic excitation strategy, the dispersion of particle distribution within the microchannels is significantly improved, and the fractal geometric dimension theory is used for quantitative characterization of the dispersion. This study demonstrates that the proposed modeling approach, combined with the ultrasonic excitation suppression strategy, effectively elucidates the mechanisms of flow field-particle mixing and mass transfer, as well as the evolution of particle flow patterns. The enhancement of turbulent characteristics in the flow field through ultrasonic excitation improves particle dispersion within the microchannels, effectively preventing particle deposition and agglomeration. Relevant results provide valuable insights into interphase interactions, cross-scale mass transfer, and particle distribution in microchannel flows, while providing technical support for optimizing mixing efficiency and dynamic processes in microfluidic chips.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116025"},"PeriodicalIF":4.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488377","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":"Role of surface tension in the thermal stress analysis of thermoelectric materials with holes","authors":"Jieyan Zhao ,&nbsp;Chuanbin Yu ,&nbsp;Haibing Yang ,&nbsp;Cunfa Gao","doi":"10.1016/j.apm.2025.116026","DOIUrl":"10.1016/j.apm.2025.116026","url":null,"abstract":"<div><div>This study investigates the mechanical behavior of a circular hole embedded in an infinite thermoelectric matrix subjected to uniform far-field current and energy flux. A weakly-conductivity surface model is employed to explore the impact of surface phonon scattering, while the complete Gurtin-Murdoch (G-M) surface model is simultaneously utilized to describe the effects of surface tension and surface elasticity. Using complex variable methods, we analytically derive the temperature and stress fields in the vicinity of the circular hole. A detailed numerical illustration for the perforated structure at small scales reveals that overall surface modulus plays a major role in determining the thermal stress field in the structure compared to surface tension, although the separate effects of surface tension on the thermal stress field would be enhanced when the surface modulus increases or a specific energy flux condition is applied. In particular, it is identified that in the case of remote energy flux applied separately, the full thermal stress field in the structure relies only on the sum of the surface modulus and surface tension (not on the specific value of each when their sum keeps a constant). The findings in the paper contribute to the understanding of the mechanical behavior of porous thermoelectric materials under complex multi-physical fields.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116026"},"PeriodicalIF":4.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474902","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 geometric framework for quasi-static manipulation of a network of elastically connected rigid bodies","authors":"Domenico Campolo ,&nbsp;Franco Cardin","doi":"10.1016/j.apm.2025.116003","DOIUrl":"10.1016/j.apm.2025.116003","url":null,"abstract":"<div><div>In this work, we propose a geometric framework for analyzing mechanical manipulation, for instance, by a robotic agent. Under the assumption of conservative forces and quasi-static manipulation, we use energy methods to derive a metric. In the first part of the paper, we review how quasi-static mechanical manipulation tasks can be naturally described via the so-called <em>force-space</em>, i.e. the cotangent bundle of the configuration space, and its Lagrangian submanifolds. Then, via a second order analysis, we derive the control Hessian of total energy. As this is not necessarily positive-definite, from an optimal control perspective, we propose the use of the squared-Hessian, also motivated by insights derived from both mechanics (Gauss' Principle) and biology (Separation Principle). In the second part of the paper, we apply such methods to the problem of an elastically-driven, inverted pendulum. Despite its apparent simplicity, this example is representative of an important class of robotic manipulation problems for which we show how a smooth elastic potential can be derived by regularizing mechanical contact. We then show how graph theory can be used to connect each numerical solution to ‘nearby’ ones, with weights derived from the very metric introduced in the first part of the paper.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116003"},"PeriodicalIF":4.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474581","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":"2D vs 3D clustering of the elliptic particulates: The correlation with the percolation thresholds","authors":"Asghar Aryanfar ,&nbsp;Mahmoud Yamani ,&nbsp;William A. Goddard III","doi":"10.1016/j.apm.2025.116007","DOIUrl":"10.1016/j.apm.2025.116007","url":null,"abstract":"<div><div>We develop a continuum percolation procedure for the aggregation of the elliptic fillers in the 2 and 3-dimensional media. Given random distributions for the locus and rotations of the elements with a specified original density <em>p</em>, each medium achieves chains of elements through overlapping to achieve a connection density of <em>ρ</em>. In this regard, typically 3<em>D</em> aggregation is more efficient than 2<em>D</em> due to the possibility of additional connectivity from the in/out (i.e. depth) directions. Hence, when increasing the number of fillers the 3D percolation system experiences an early increase in the connection density <em>ρ</em>, which typically occurs in the neighborhood of the percolation threshold <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>. We initially develop a new iterative method to compute the percolation threshold <span><math><msub><mrow><mi>p</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span> in finite systems. Subsequently, we show that such early divergence between 2D-3D percolation systems is followed by a later convergence stage, as the number of fillers progressively increases. Consequently, we show, conceptually and computationally, that the maximum 2D-3D difference in the connections density <span><math><mi>Δ</mi><msub><mrow><mi>ρ</mi></mrow><mrow><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math></span> correlates directly with the respective 2D-3D difference in the percolation thresholds <span><math><mi>Δ</mi><msub><mrow><mi>p</mi></mrow><mrow><mi>c</mi></mrow></msub></math></span>, where a large pool of computational samples were generated by varying the aspect ratio as well as the relative scale of the particles. The results and respective analyses could be useful for the design of binary composite membranes of a specified thickness (i.e. thin<span><math><mo>→</mo><mn>2</mn><mi>D</mi></math></span>, thick<span><math><mo>→</mo><mn>3</mn><mi>D</mi></math></span>) for achieving the desired homogenized physical property.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116007"},"PeriodicalIF":4.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510775","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":"Fixed-time fault-tolerant formation-containment control for unmanned helicopters via a fully actuated system approach","authors":"Yuan Lu ,&nbsp;Ke Zhang ,&nbsp;Lihua Shen ,&nbsp;Jingping Xia","doi":"10.1016/j.apm.2025.116004","DOIUrl":"10.1016/j.apm.2025.116004","url":null,"abstract":"<div><div>This paper investigates the fixed-time fault-tolerant formation-containment control problem for unmanned helicopters (UHs) with collision and obstacle avoidance. Firstly, a high-order fully actuated system model of the UH with actuator faults is developed, which includes position and attitude subsystems. Secondly, based on the null space method, the tasks performed by multiple UHs are decomposed into collision avoidance tasks, obstacle avoidance tasks and cooperative flight tasks, and the desired trajectory is obtained by task fusion according to the priority. Then, a fixed-time disturbance observer is constructed to estimate the fault information of each UH, which is convenient for the controller to compensate for the effect of faults. With the aid of the fully actuated system approach, the fault-tolerant formation-containment controller is designed, guaranteeing that tracking errors converge to the prescribed performance range within a fixed time. Finally, the simulation results are provided to demonstrate the effectiveness of the proposed control strategy.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116004"},"PeriodicalIF":4.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143452912","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":"Identification for generalized Hammerstein models with multiple switching linear dynamics","authors":"Xiaotong Xing,&nbsp;Jiandong Wang","doi":"10.1016/j.apm.2025.116001","DOIUrl":"10.1016/j.apm.2025.116001","url":null,"abstract":"<div><div>Generalized Hammerstein models are defined as a type of Hammerstein models with a specific structure, consisting of a static nonlinear submodel connected with multiple switching dynamic linear submodels. They offer a separate structured representation for the overall static gains and changing dynamic characteristics of nonlinear systems, facilitating nonlinear inverse compensation and robust controller design for efficient control. This paper proposes a method for identifying generalized Hammerstein models and measuring their modeling uncertainties. Specifically, a generalized Hammerstein model activated by multiple validity functions is established, and its optimal parameter vector is estimated by solving a nonlinear and nonconvex optimization problem. Modeling uncertainties of generalized Hammerstein models are measured by some suboptimal parameter vectors according to fuzzy set theory. These vectors have the properties that their objective function values are close to the optimal one and their simulated outputs can reproduce certain measured outputs. In numerical and experimental examples, the proposed method establishes a generalized Hammerstein model that can well describe nonlinear systems with changing dynamic characteristics, and provides accurate and compact measurements of modeling uncertainties. By contrast, existing Hammerstein model identification methods yield inaccurate results due to model structural errors.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116001"},"PeriodicalIF":4.4,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444665","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 elastoplastic analytical method for characterizing the plastic zone around a shallow circular tunnel","authors":"Chao Wang ,&nbsp;Jinfeng Zou ,&nbsp;Yichuan Zhu ,&nbsp;Liang Li","doi":"10.1016/j.apm.2025.115999","DOIUrl":"10.1016/j.apm.2025.115999","url":null,"abstract":"<div><div>This research proposes an elastoplastic analytical method for characterizing the plastic zone around a shallow circular tunnel, based on Mohr-Coulomb yield criterion. Using conformal mapping, we transformed a semi-infinite planar region with a vertically axisymmetric hole with arbitrary shapes into an annulus with a simple boundary shape. The combined effect of the unit weight of surrounding rock and the uniform surface surcharge pressure is considered to derive the theoretical solutions for elastic stress functions of surrounding rock in a shallow circular tunnel and plastic stress components of surrounding rock based on Mohr-Coulomb yield criterion. Nonlinear equations involving the mapping function coefficients are established according to boundary stress and strain conditions at the ground surface, and stress continuity conditions at the elastic-plastic interface. These coefficients are set as design variables, and solutions are developed for elastic stress functions and plastic zone range of a shallow circular tunnel, with a newly proposed mapping function and a newly defined fitness function through differential-evolution algorithm. The rationality of the proposed method is verified by comparing to the numerical simulation results, showing improved accuracy compared to existing methods. Its engineering applicability is also verified by comparing to the field monitoring results. Finally, the main factors influencing the plastic zone around a shallow circular tunnel are characterized. The proposed method can provide theoretical support for optimizing engineering design and construction parameters, including surrounding rock stress, plastic radius, excavation depth, and radius of shallow buried tunnels.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 115999"},"PeriodicalIF":4.4,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551060","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":"Actuation and design of two-dimensional curved hard-magnetic soft bilayers","authors":"Lujia Liu ,&nbsp;Huadong Yong","doi":"10.1016/j.apm.2025.116005","DOIUrl":"10.1016/j.apm.2025.116005","url":null,"abstract":"<div><div>Hard-magnetic soft actuators (HMSAs) has gained prominence for its application in magnetically steerable soft robots, such as robotic grippers. Compared to straight HMS beam, the magneto-mechanical response of continuous and discontinuous curved multilayered HMSA under external magnetic fields is more complex. Based on the finite deformation theory and nonlinear theory of hard magnetoelasticity, this paper develops a theoretical model for a residually stressed curved HMS bilayer induced by pre-stretch under external magnetic fields. It is found that the bending angle of the bilayer can be adjusted by tuning the pre-stretch, thickness ratio and shear modulus ratio. This bending angle influences the magneto-mechanical response of the bilayer, thereby affecting the set of points reachable at the free-end of the bilayer (i.e., the workspace). The theoretical model's accuracy is validated through comparisons with experimental and simulation results. The study finds that as the pre-stretch increases, the thickness ratio and shear modulus ratio of the bilayer decrease, leading to opposite trends between workspace, maximum curvature and weight. Furthermore, based on the theoretical model, the Non-dominated Sorting Genetic Algorithm-II (NSGA-II) is adopted to address the multi-objective optimization problem of HMS bilayer. The Pareto fronts of the three-objective optimization containing weight, maximum curvature and workspace are obtained. This work provides the theoretical guidance for designing and optimizing magnetically soft robots in future applications.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116005"},"PeriodicalIF":4.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471666","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 generalized isogeometric-analysis-based method for assembly accuracy prediction considering non-ideal surface morphology and part deformation","authors":"Yitao Yang ,&nbsp;Qiangqiang Zhao ,&nbsp;Dewen Yu ,&nbsp;Xiaokun Hu ,&nbsp;Xiaohu Li ,&nbsp;Jun Hong","doi":"10.1016/j.apm.2025.116000","DOIUrl":"10.1016/j.apm.2025.116000","url":null,"abstract":"<div><div>Assembly accuracy generally determines the work performance of a precise mechanical product, and how to accurately predict it is highly concerned. However, previous methods cannot mostly consider the coupling effect of non-ideal surface morphology and part deformation, which are inevitably introduced during manufacturing and assembly processes. Therefore, this paper develops a novel assembly accuracy prediction method that considers non-ideal surface morphology and part deformation based on isogeometric analysis (IGA). First, the non-uniform rational B-spline (NURBS) is introduced to represent non-ideal surface morphology accurately. Next, we develop a contact detection method for non-ideal surfaces. Based on this, we propose a method to determine the initial contact state, implement a three-dimensional contact algorithm to solve the contact problem, and use IGA to calculate part deformation. Finally, the precision of the proposed method is verified by comparing it with traditional methods. The comparison indicates that the impact of non-ideal surface morphology and part deformation cannot be ignored. In addition, this paper uses NURBS as the basis of non-ideal surface morphology representation and part deformation analysis, eliminates the partition between computer aided design (CAD) and computer aided engineering (CAE), and realizes the high-precision prediction of assembly accuracy.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 116000"},"PeriodicalIF":4.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463852","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":"Use of simplified models for estimating the dynamic response of a cross-anisotropic poroelastic half-plane to a load moving on its surface","authors":"Zhenyu Liu ,&nbsp;Niki D. Beskou ,&nbsp;Edmond V. Muho ,&nbsp;Ying Zhou","doi":"10.1016/j.apm.2025.115998","DOIUrl":"10.1016/j.apm.2025.115998","url":null,"abstract":"<div><div>Three simplified models for the analytic determination of the dynamic response of a cross-anisotropic poroelastic half-plane to a load moving with constant speed on its surface are presented and compared against the corresponding exact model. The method of analysis of the exact and approximate models uses complex Fourier series to expand the load and the displacement responses along the horizontal direction of the steady-state motion and thus reduces the partial differential equations of the problem to ordinary ones, which are easily solved. The three simplified models are characterized by reasonable simplifying assumptions, which reduce the complexity of the exact model and facilitate the solution. In the first simplified model all the terms of the equations of motion associated with fluid acceleration are neglected. In the second simplified model, solid displacements are assumed to be equal to the corresponding fluid ones, while the third simplified model is the second one corrected with respect to the fluid pressure at the free boundary (top) layer. All three simplified models are compared with respect to their accuracy against the exact model and the appropriate range of values of the various significant parameters of the problem, like porosity, permeability, anisotropy indices, or load speed, for obtaining approximate solutions as close to the exact solution as possible is thoroughly discussed.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"143 ","pages":"Article 115998"},"PeriodicalIF":4.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510776","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}