{"title":"Nonlinear vortex-induced dynamics and post-buckling analysis of fluid-conveying pipelines with complex constraint","authors":"Ye Tang , Xinru Zhang , Yaxin Zhen","doi":"10.1016/j.apm.2025.116244","DOIUrl":"10.1016/j.apm.2025.116244","url":null,"abstract":"<div><div>The paper investigates the nonlinear vortex-induced vibration (VIV) of fluid-conveying pipelines in the supercritical state under the impact of external fluid, axial tension, and the complex constraints of vertical and torsional springs. The nonlinear governing eqs. are derived by applying Hamilton's principle in conjunction with the van der Pol equation. The numerical modes are received using the differential quadrature method combined with Gauss-Legendre nodes. The nonlinear motion eqs. of the coupled system are discretized by the numerical modes in conjunction with the Galerkin method and are solved utilizing the Runge-Kutta methodology. The results show that the variations of the vertical spring and torsional spring will affect the dynamic stiffness of the pipelines in the pre-buckling and post-buckling regimes, which will lead to a change in the displacement response of the pipelines. The introduction of spring complex constraints significantly enhances the critical velocity of the pipeline, and as the internal fluid velocity increases beyond the critical threshold again, the pipeline transitions into an ultra-supercritical state. The buckling angle exhibits negligible influence on the first-order natural frequency.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"148 ","pages":"Article 116244"},"PeriodicalIF":4.4,"publicationDate":"2025-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241065","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":"Spatio-temporal grey model based on tensor Tucker decomposition for traffic flow prediction","authors":"Xingwu Wang , Huiming Duan , Fengmin Yu","doi":"10.1016/j.apm.2025.116231","DOIUrl":"10.1016/j.apm.2025.116231","url":null,"abstract":"<div><div>Short-term traffic flow prediction plays an increasingly important role in intelligent transportation systems, providing a decision-making basis for traffic signal optimization, route guidance, and emergency control, thereby improving the efficiency of road network operation. However, the traffic flow system is a complex dynamic system, and its data has complex spatio-temporal multi-modal characteristics. The existing grey models take time series and matrix series as the input of metadata, ignoring the multi-modal characteristics of traffic flow data, and have certain limitations in capturing the spatial correlation and dynamic spatio-temporal interaction of traffic flow. This paper introduces tensors with high-dimensional multi-modal features as metadata and establishes a novel tensor-structured discrete grey model. The new model reconstructs the multi-dimensional spatio-temporal attributes of traffic flow data and traditional multi-segment traffic data, follows the discrete grey model's modeling mechanism and prediction method, and retains the advantages of fast calculation efficiency and high prediction accuracy of the grey model. It also makes up for the defect that the grey model can only handle small-scale data, providing a new idea for the multi-dimensional prediction extension of the grey model. To illustrate the effectiveness of the new model, traffic data from multiple periods and multiple road sections are simulated and predicted. The simulation effectiveness index (Mean Absolute Percentage Error) values of the new model in different periods of the same road section and the same period of different road sections are all around 5 %, and it also has a better performance compared with the other three-time series prediction models.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"148 ","pages":"Article 116231"},"PeriodicalIF":4.4,"publicationDate":"2025-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241592","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":"Elastic-plastic responses of rectangular multi-cell beams under three-point bending","authors":"Xinrong Fu , Xiong Zhang","doi":"10.1016/j.apm.2025.116227","DOIUrl":"10.1016/j.apm.2025.116227","url":null,"abstract":"<div><div>Thin-walled beams are widely applied in modern industrial products as structural or energy-absorbing components. They are often subject to bending loads and undergo large deformation. How to predict their elastic-plastic bending responses accurately by theoretical methods is still a quite challenging task. In this work, we propose a theoretical method to give more accurate solution on the elastic-plastic bending responses of thin-walled beams. Experimental tests of triple-cell aluminum alloy beams are first carried out, and numerical analyses are then performed. The nonlinear bending moment distribution of multi-cell beams along the span is revealed. Theoretical expressions are derived for elastic-plastic bending moments of multi-cell sections with 1 × <em>m</em> and 2 × <em>m</em> cells. The theoretical method to achieve the three-point bending responses of the multi-cell beams is then introduced, based on a large deformation three-point bending model. The conversion relations between the bending moment response and the force response are also provided. Finally, the effectiveness of the proposed method is validated by experimental and numerical results of multi-cell beams with different sectional shapes.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"148 ","pages":"Article 116227"},"PeriodicalIF":4.4,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144222211","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 inventory routing problem with route and schedule unpredictability","authors":"Marlize H. Visser, Jan H. van Vuuren","doi":"10.1016/j.apm.2025.116228","DOIUrl":"10.1016/j.apm.2025.116228","url":null,"abstract":"<div><div>The <em>inventory routing problem</em> (IRP) in a retail supply chain setting allows for the simultaneous optimisation of delivery schedules, vehicle routes, and delivery quantities. The IRP relies on the adoption of a vendor-managed inventory strategy which has the potential to reduce transportation, inventory, and stock-out costs in a supply chain. In this paper, we introduce a mathematical model for a new IRP variant, the <em>heterogeneous fixed fleet IRP with time-windows</em> (HeFIRPTW) with route and schedule unpredictability, in the form of a bi-objective mixed-integer linear programming problem. This model simultaneously incorporates route and schedule unpredictability aimed at mitigating inherent safety and security threats experienced during the transportation of valuable goods. Delivery routes and schedules are generated that minimise the operational costs incurred whilst also ensuring that route segments are not traversed too regularly and that customers are not visited during overlapping daily time intervals. The feasibility of adopting an exact <em>ϵ</em>-constrained model solution method is investigated empirically by solving small, adapted benchmark instances of the problem. An investigation into the model solution complexity for varying problem sizes reveals that unpredictability, particularly with tightened constraints, increases the computational time. The complexity implications of multiple vehicles and the imposition of time-windows are also examined. The results highlight the computational demands of the proposed model, demonstrating a clear need for a faster, perhaps approximate, solution approach capable of generating high-quality solutions for realistic problem instances within reasonable time-frames.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116228"},"PeriodicalIF":4.4,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144194885","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":"Fractional-order viscoelastic model for tendons with multilevel self-similar structures","authors":"Xin Wang, Jianqiao Guo","doi":"10.1016/j.apm.2025.116222","DOIUrl":"10.1016/j.apm.2025.116222","url":null,"abstract":"<div><div>Tendons share multilevel self-similar structures from the molecular to macroscopic levels, and their long-range viscoelastic responses have significant biomechanical implications in clinical settings. Existing research has not adequately studied the correlation between the tendon’s multilevel structure and its viscoelastic behaviour. This study proposes a fractional-order viscoelastic model for tendons that describes their multilevel self-similar structures. A self-similar spring-dashpot network is abstracted from the multilevel structures of tendons, and the spring-dashpot parameters corresponding to adjoint structural levels are assumed to be described by a power-law relationship. The constitutive equations of the viscoelastic model can be derived using Heaviside’s operational calculus, which shows that the long-range viscoelastic response of the tendon can be described by a tempered fractional-order operator and that the fractional order nonlinearly combines the effect of the power-law scaling factor and structural self-similarity. The proposed model is validated to fit the tendon relaxation response described at the macroscopic and micro-nano levels in the literature. The fitting performance is also found to be better than that without consideration of power-law characteristics. In addition, the geometrical definition of the fractal dimension is extended to the proposed fractional-order viscoelastic model, which provides a theoretical foundation for understanding the connections between the multilevel structure of soft biomaterials and their time-dependent biomechanical functions.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116222"},"PeriodicalIF":4.4,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204132","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}
Roger Miranda-Colorado , Jesús A. Rodríguez-Arellano , Luis T. Aguilar
{"title":"Control of a 2D-crane system with payload swing attenuation: An observer-based prescribed-time approach","authors":"Roger Miranda-Colorado , Jesús A. Rodríguez-Arellano , Luis T. Aguilar","doi":"10.1016/j.apm.2025.116226","DOIUrl":"10.1016/j.apm.2025.116226","url":null,"abstract":"<div><div>A crane system has a variety of applications in industry and for research purposes. However, this system is underactuated and is always affected by disturbances, which compromises the controller design stage. Then, this work develops a new control scheme to control two-dimensional (2D) perturbed overhead cranes. The new proposal separates the controller into two parts. The first controller component is utilized to compensate for disturbances. The second control consists of a switching controller combining a variable-gain scheme and a variable-structure methodology. The new proposal attains prescribed-time convergence for the unperturbed case and asymptotic convergence for the perturbed case. Extensive simulations demonstrate that the tracking errors exhibit low values with low power demands under different initial conditions and matched and unmatched disturbances while payload oscillations are attenuated effectively. Besides, experiments demonstrate the superiority of the novel control methodology with the lowest tracking errors in the trolley and rope; also, payload variations are reduced to half of the value obtained with the best of the controllers used for comparison, demonstrating the appealing features of the new proposal.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116226"},"PeriodicalIF":4.4,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170189","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":"Synchronization of bursting oscillations in coupled FitzHugh-Nagumo neurons","authors":"Haolan Wang, Danjin Zhang, Youhua Qian","doi":"10.1016/j.apm.2025.116219","DOIUrl":"10.1016/j.apm.2025.116219","url":null,"abstract":"<div><div>The research of bursting oscillations in neuronal models not only enriches the study of nonlinear dynamics, but also deepens the understanding of the working mechanism of the brain. A coupled FitzHugh-Nagumo (FHN) neuron model can be simulated by connecting two resistor-inductor-capacitor circuits via a resistor. Taking into account the external excitation as a slow variable, the FHN neuron model can be converted into a generalized autonomous system. Fast-slow analysis is used to investigate the phenomenon of bursting oscillations produced by two identical neurons and two non-identical neurons independently. By examining the superposition of the equilibrium curves with the transformed phase diagrams, the generation mechanisms of the six bursting oscillation behaviors are revealed. Meanwhile, the synchronization phenomenon between two neurons is verified in conjunction with the related synchronization theory. Furthermore, the cause for the antiphase synchronization of the system generating bursting oscillations is elaborated.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116219"},"PeriodicalIF":4.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170058","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}
Chang C.Y. Dorea , Roberto Vila , Cecilia Castro , Víctor Leiva , Felipe S. Quintino
{"title":"Revisiting fatigue-life distributions of Birnbaum-Saunders type: Mathematical characterization, simulation study, and applications","authors":"Chang C.Y. Dorea , Roberto Vila , Cecilia Castro , Víctor Leiva , Felipe S. Quintino","doi":"10.1016/j.apm.2025.116223","DOIUrl":"10.1016/j.apm.2025.116223","url":null,"abstract":"<div><div>The Birnbaum-Saunders (BS) distribution is a fundamental model in reliability engineering and risk analysis, relating failure time to the accumulation of incremental damage. This accumulation is traditionally assumed to follow normality, although such an assumption may fail under heavy-tailed processes with potentially unbounded variability. We extend the BS distribution to a more general family driven by stable-type increments, designed to handle both moderate and extremely heavy tails. This extension is supported by a generalized convergence argument. We introduce novel estimators —based on tail and characteristic function methods— which effectively capture extreme tail behavior, even with moderate sample sizes. We illustrate the practical benefits of our approach by examining two real insurance-claim datasets (finite-variance versus infinite-variance). The first is the Allstate dataset, a large auto-claim dataset available on Kaggle, for which a stable BS model with finite variance proves sufficient. The second is a French motor third-party liability dataset whose exceptionally high individual claims justify an unbounded-variance model. These contrasting illustrations demonstrate how the extended BS framework can reveal whether infinite variability is warranted and guide practitioners toward models that are both theoretically sound and empirically reliable for risk assessment. Overall, our findings broaden the applicability of the BS distribution to extreme-event scenarios, providing a flexible framework capable of distinguishing between finite- and infinite-variance behaviors in contemporary reliability and actuarial applications.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116223"},"PeriodicalIF":4.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144204131","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}
Zuliang Lu , Junman Li , Lu Xing , Mingsong Li , Zhihui Cao , Zhuran Xiang
{"title":"Research on basin ecological compensation in the Yangtze River Economic Belt based on the three-way-decision theory","authors":"Zuliang Lu , Junman Li , Lu Xing , Mingsong Li , Zhihui Cao , Zhuran Xiang","doi":"10.1016/j.apm.2025.116215","DOIUrl":"10.1016/j.apm.2025.116215","url":null,"abstract":"<div><div>Nowadays, increasing pollution problems in major basins in China are becoming serious due to the acceleration of urbanization, and transboundary pollution problems are particularly deteriorating. The pollutants generated by production in the upstream area enter the midstream area with water flow and eventually reach the downstream area, causing adverse effects on the local ecological environment and people's health and even the whole country. To address this issue, a basin ecological compensation model was established in this study. This model includes a series of indicators and parameters that may affect the government's revenue, such as subsidies or penalties. Compared with most other existing research results, the innovation in this paper and marginal contributions of this paper are as follows: (1) In this study, we clarify the usual division of the role among the upstream, midstream, and downstream in basin ecological compensation. Introducing “the midstream area” expands a two-party evolutionary game into the three-party evolutionary game. This is very helpful to sort out the conflicts of interest among various stakeholders in the system. In addition, the model combines the three-way-decision theory to expand strategies that governments can choose in the game. (2) We draw inspiration from rough set theory based decision-making methods and introduce the three-way decision theory to handle uncertainty, forming three decision options: accept, reject, and deferment. This decision-making approach is more in line with the decision-making process of stakeholders in reality and can reduce the risks brought by uncertainty. The established ecological compensation model in this paper predicted strategy decisions of the upstream, midstream, and downstream governments on various emerging issues. (3) In empirical simulation, taking the Yangtze River Economic Belt in China as a case study, and Hubei Province, Anhui Province, and Jiangsu Province as main research objects, the feasibility and effectiveness of the model were verified through numerical simulation. The following conclusions are drawn in this paper: (i) The change in the initial probability of each government will not alter the final evolutionary result of the entire evolutionary game system, but will alter the system's evolutionary process; (ii) When the government tends to choose negative or deferment decision, other governments may be in a hesitant state in the short term; (iii) Changes in the initial conditional probability of Anhui Province will affect the decision-making evolutionary time of Hubei Province and Jiangsu Province when other conditions remain constant. This study provides an effective approach to protect the sustainable development of basins and improve related ecological compensation policies.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116215"},"PeriodicalIF":4.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170190","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":"Gradient-free score-based sampling methods with ensembles","authors":"Bryan Riel , Tobias Bischoff","doi":"10.1016/j.apm.2025.116224","DOIUrl":"10.1016/j.apm.2025.116224","url":null,"abstract":"<div><div>Recent developments in generative modeling have utilized score-based methods coupled with stochastic differential equations to sample from complex probability distributions. However, these and other performant sampling methods generally require gradients of the target probability distribution, which can be unavailable or computationally prohibitive in many scientific and engineering applications. Here, we introduce ensembles within score-based sampling methods to develop gradient-free approximate sampling techniques that leverage the collective dynamics of particle ensembles to compute approximate reverse diffusion drifts. We introduce the underlying methodology, emphasizing its relationship with generative diffusion models and the previously introduced Föllmer sampler. We demonstrate the efficacy of the ensemble strategies through various examples, ranging from low- to medium-dimensionality sampling problems, including multi-modal and highly non-Gaussian probability distributions, and provide comparisons to traditional methods like the No-U-Turn Sampler. Additionally, we showcase these strategies in the context of a high-dimensional Bayesian inversion problem within the geophysical sciences. Our findings highlight the potential of ensemble strategies for modeling complex probability distributions in situations where gradients are unavailable.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"147 ","pages":"Article 116224"},"PeriodicalIF":4.4,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170057","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}