Pub Date : 2025-12-12DOI: 10.1016/j.apm.2025.116664
Zehua Si , Zhixue He , Sho Kawano , Jun Tanimoto
Rewards are powerful mechanisms for sustaining cooperation, yet previous models consider unconditional prosocial rewarding, where cooperators indiscriminately reward other cooperators at a fixed cost. This simplification facilitates analysis but neglects the adaptive and context-dependent nature of real behavior. To capture such adaptability, we extend the spatial prisoner’s dilemma by proposing a conditional prosocial rewarding mechanism, where individuals provide rewards only when their cooperative partners face stronger defection pressure, with reward intensity increasing as local disparities grow. Our Monte Carlo simulations reveal that the reward-to-cost ratio defines a critical threshold for the effectiveness of the rewarding mechanism. Conditional rewarding can achieves higher stable cooperation than unconditional rewarding under both weak and strong dilemma conditions, within specific reward parameter ranges. Spatiotemporal analysis further shows that conditional rewarding can invade defectors where unconditional rewarding fails. These findings highlight the adaptive nature of conditional incentives and provide theoretical guidance for designing more effective and resource-efficient strategies to promote cooperation in structured populations.
{"title":"Can conditional prosocial rewarding outperform unconditional prosocial rewarding in promoting cooperation within structured populations?","authors":"Zehua Si , Zhixue He , Sho Kawano , Jun Tanimoto","doi":"10.1016/j.apm.2025.116664","DOIUrl":"10.1016/j.apm.2025.116664","url":null,"abstract":"<div><div>Rewards are powerful mechanisms for sustaining cooperation, yet previous models consider unconditional prosocial rewarding, where cooperators indiscriminately reward other cooperators at a fixed cost. This simplification facilitates analysis but neglects the adaptive and context-dependent nature of real behavior. To capture such adaptability, we extend the spatial prisoner’s dilemma by proposing a conditional prosocial rewarding mechanism, where individuals provide rewards only when their cooperative partners face stronger defection pressure, with reward intensity increasing as local disparities grow. Our Monte Carlo simulations reveal that the reward-to-cost ratio defines a critical threshold for the effectiveness of the rewarding mechanism. Conditional rewarding can achieves higher stable cooperation than unconditional rewarding under both weak and strong dilemma conditions, within specific reward parameter ranges. Spatiotemporal analysis further shows that conditional rewarding can invade defectors where unconditional rewarding fails. These findings highlight the adaptive nature of conditional incentives and provide theoretical guidance for designing more effective and resource-efficient strategies to promote cooperation in structured populations.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116664"},"PeriodicalIF":4.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731459","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}
Pub Date : 2025-12-12DOI: 10.1016/j.apm.2025.116689
Hongbiao Zhao , Peter Stansby , Zhijing Liao , Guang Li
This paper presents a nonlinear model predictive control framework for a hybrid floating offshore wind-wave platform that integrates a wind turbine with a wave energy converter with multiple floats to achieve multi-objective control tasks. The control framework simultaneously maximizes wave energy extraction and minimizes platform motions to enhance operational safety. Nonlinear aerodynamic and hydrodynamic viscous effects are explicitly incorporated into the controller design to significantly improve control performance. To further improve control performance, wave prediction information is incorporated into the control formulation to achieve non-causal optimality. The multiple shooting method and a sequential quadratic programming algorithm are employed to solve the control problem online with tractable computational efficiency. Numerical simulations under various sea states demonstrate that the proposed controller can approximately double the harvested wave energy compared with existing control approaches while maintaining platform motions within safe operational limits.
{"title":"Noncausal multi-objective nonlinear control for a hybrid floating offshore wind-wave platform","authors":"Hongbiao Zhao , Peter Stansby , Zhijing Liao , Guang Li","doi":"10.1016/j.apm.2025.116689","DOIUrl":"10.1016/j.apm.2025.116689","url":null,"abstract":"<div><div>This paper presents a nonlinear model predictive control framework for a hybrid floating offshore wind-wave platform that integrates a wind turbine with a wave energy converter with multiple floats to achieve multi-objective control tasks. The control framework simultaneously maximizes wave energy extraction and minimizes platform motions to enhance operational safety. Nonlinear aerodynamic and hydrodynamic viscous effects are explicitly incorporated into the controller design to significantly improve control performance. To further improve control performance, wave prediction information is incorporated into the control formulation to achieve non-causal optimality. The multiple shooting method and a sequential quadratic programming algorithm are employed to solve the control problem online with tractable computational efficiency. Numerical simulations under various sea states demonstrate that the proposed controller can approximately double the harvested wave energy compared with existing control approaches while maintaining platform motions within safe operational limits.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116689"},"PeriodicalIF":4.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145732364","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}
Pub Date : 2025-12-12DOI: 10.1016/j.apm.2025.116684
Pei Zheng, Jian Jiang
In this research, based on the current configuration, the balance equations and traction boundary conditions are derived by using the principle of virtual power for materials with the dilatational strain gradient. As a specialization, the constitutive equations of the linear theory are derived. To solve the boundary-value problems in the linear theory, the classical stress function approach for plane problems is generalized to the case of dilatational strain gradient elasticity. Then, using the stress functions, the problem of determining the stresses in the elastic body is reduced to that of finding the solution of compatibility equations with the prescribed boundary conditions. As an application of the stress functions, the problem of circular hole in an infinite plate is examined. The corresponding analytical solution is found by a split of the original problem into axisymmetric and asymmetric ones. The stress-concentration factors at the edge of the hole in simple tension, biaxial tension, and pure shear are determined and they are compared with those obtained from the conventional theory as well as from the couple-stress theory. It is shown that, when the Poisson’s ratio equals zero, the influence of the double-force stress on stress concentrations disappears, unlike the couple-stress effect.
{"title":"Stress functions for plane problems in linear dilatational strain gradient elasticity and the effect of the double-force stress on stress concentrations","authors":"Pei Zheng, Jian Jiang","doi":"10.1016/j.apm.2025.116684","DOIUrl":"10.1016/j.apm.2025.116684","url":null,"abstract":"<div><div>In this research, based on the current configuration, the balance equations and traction boundary conditions are derived by using the principle of virtual power for materials with the dilatational strain gradient. As a specialization, the constitutive equations of the linear theory are derived. To solve the boundary-value problems in the linear theory, the classical stress function approach for plane problems is generalized to the case of dilatational strain gradient elasticity. Then, using the stress functions, the problem of determining the stresses in the elastic body is reduced to that of finding the solution of compatibility equations with the prescribed boundary conditions. As an application of the stress functions, the problem of circular hole in an infinite plate is examined. The corresponding analytical solution is found by a split of the original problem into axisymmetric and asymmetric ones. The stress-concentration factors at the edge of the hole in simple tension, biaxial tension, and pure shear are determined and they are compared with those obtained from the conventional theory as well as from the couple-stress theory. It is shown that, when the Poisson’s ratio equals zero, the influence of the double-force stress on stress concentrations disappears, unlike the couple-stress effect.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116684"},"PeriodicalIF":4.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731458","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}
Pub Date : 2025-12-11DOI: 10.1016/j.apm.2025.116691
Xiaobo Bi , Ye Li , Xujian Lyu , Hui Tang
Fully coupled fluid-structure-electrical interaction of piezoelectric plates plays a key role in many aero- and hydro-piezoelectric applications, such as energy harvesting from ambient fluid flows and direct actuation of flexible plates for biomimetic propulsion. Many of these applications involve complex three-dimensional flow dynamics and structure dynamics. Yet, a three-dimensional high-fidelity modeling framework for simulating these multi-physical problems is still scarce. In this study, we present a numerical framework of this kind. Using the Hamilton’s principle and the reduced constitutive law of piezoelectric plates, the governing equations and boundary conditions of an electromechanical system are formulated. These equations are then coupled with the incompressible Navier-Stokes equations using the continuous forcing immersed boundary method, forming a set of governing equations describing multi-physics phenomena involving strong three-dimensional fluid-structure-electrical interactions. The accuracy of the numerical model is verified by three test cases through comparisons with benchmark results. We then demonstrate the full capacity of this framework through two representative case studies: one is flow energy harvesting using a piezoelectric plate undergoing flow-induced fluttering and the other is thrust generation using a flapping plate driven through inverse piezoelectricity. This numerical framework also has great potentials in modeling many other applications involving strong piezoelectricity-related fluid-structure-electrical interactions, such as piezoelectric-actuated active flow/vibration/noise control.
{"title":"Three-dimensional fluid-structure-electrical interaction modeling of piezoelectric plates","authors":"Xiaobo Bi , Ye Li , Xujian Lyu , Hui Tang","doi":"10.1016/j.apm.2025.116691","DOIUrl":"10.1016/j.apm.2025.116691","url":null,"abstract":"<div><div>Fully coupled fluid-structure-electrical interaction of piezoelectric plates plays a key role in many aero- and hydro-piezoelectric applications, such as energy harvesting from ambient fluid flows and direct actuation of flexible plates for biomimetic propulsion. Many of these applications involve complex three-dimensional flow dynamics and structure dynamics. Yet, a three-dimensional high-fidelity modeling framework for simulating these multi-physical problems is still scarce. In this study, we present a numerical framework of this kind. Using the Hamilton’s principle and the reduced constitutive law of piezoelectric plates, the governing equations and boundary conditions of an electromechanical system are formulated. These equations are then coupled with the incompressible Navier-Stokes equations using the continuous forcing immersed boundary method, forming a set of governing equations describing multi-physics phenomena involving strong three-dimensional fluid-structure-electrical interactions. The accuracy of the numerical model is verified by three test cases through comparisons with benchmark results. We then demonstrate the full capacity of this framework through two representative case studies: one is flow energy harvesting using a piezoelectric plate undergoing flow-induced fluttering and the other is thrust generation using a flapping plate driven through inverse piezoelectricity. This numerical framework also has great potentials in modeling many other applications involving strong piezoelectricity-related fluid-structure-electrical interactions, such as piezoelectric-actuated active flow/vibration/noise control.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116691"},"PeriodicalIF":4.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731463","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}
Pub Date : 2025-12-11DOI: 10.1016/j.apm.2025.116683
Ivano Colombaro , Marc Tudela-Pi
Modeling relaxation phenomena in complex media is central to understanding multiscale dynamics in materials science, bioengineering and condensed matter physics. Existing fractional-order models, while flexible, sometimes lack physical interpretability, closed-form time-domain expressions, and compatibility with physically realizable architectures. In this work, we propose a novel passive element whose impedance and admittance are defined analytically via modified Bessel functions of first kind, through the electro-mechanical analogy. This approach preserves key physical properties such as analyticity, passivity, BIBO (bounded-input, bounded-output) stability and monotonicity, while enabling the direct use of its time-domain representation in simulations and system modeling. As an application, we demonstrate that this model accurately captures the broadband dispersive behavior of biological tissues, offering a physically grounded and tractable alternative to fractional-order formulations.
{"title":"On mathematical characterization of a Bessel functions-based passive element in electronic circuits","authors":"Ivano Colombaro , Marc Tudela-Pi","doi":"10.1016/j.apm.2025.116683","DOIUrl":"10.1016/j.apm.2025.116683","url":null,"abstract":"<div><div>Modeling relaxation phenomena in complex media is central to understanding multiscale dynamics in materials science, bioengineering and condensed matter physics. Existing fractional-order models, while flexible, sometimes lack physical interpretability, closed-form time-domain expressions, and compatibility with physically realizable architectures. In this work, we propose a novel passive element whose impedance and admittance are defined analytically via modified Bessel functions of first kind, through the electro-mechanical analogy. This approach preserves key physical properties such as analyticity, passivity, BIBO (bounded-input, bounded-output) stability and monotonicity, while enabling the direct use of its time-domain representation in simulations and system modeling. As an application, we demonstrate that this model accurately captures the broadband dispersive behavior of biological tissues, offering a physically grounded and tractable alternative to fractional-order formulations.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116683"},"PeriodicalIF":4.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731462","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}
Pub Date : 2025-12-10DOI: 10.1016/j.apm.2025.116680
Zhe Feng , Pedro A. Vázquez , Mengqi Zhang
This work investigates the bifurcation and chaos in 2-D electroconvective (EC) flows of a dielectric liquid confined between two infinite parallel plates subjected to an electric potential difference. To further characterise its nonlinear dynamics, we compute the lower-branch unstable equilibrium solutions in the EC flow using the Jacobian-free Newton-Krylov method with a pseudo-arclength continuation technique and study their perturbative dynamics by the global linear stability analysis. These lower-branch unstable solutions are shown to act as edge states that delineate the initial conditions leading either to the hydrostatic state or to the upper-branch stable solutions. As the electric Rayleigh number T (measuring the strength of the electric field) increases, the electric Nusselt number Ne for these solutions decreases and the so-called charge-void region shrinks. Beyond the linear instability, an optimal horizontal wavelength corresponding to the strongest electric transport is identified among the upper-branch solutions. The upper-branch solution will undergo a Hopf bifurcation with the increase of T. The onset of Hopf bifurcation is accurately determined by the global linear stability analysis and this bifurcation is found to be of a supercritical nature. A larger mobility ratio M (quantifying the charge mobility) increases the value of the threshold for the Hopf bifurcation. When T further increases, the EC flow becomes chaotic, which can transiently visit two- and four-roll structures. In addition, the transition from periodic oscillation to chaos is found to be subcritical for the first time. We also find that the power spectra density in the chaotic EC flow decays following a power law with the exponent around 7, which is consistent with the experimental observation. The investigation of the nonlinear EC flow in this work may be helpful for a more complete understanding of its nonlinear dynamics.
{"title":"Nonlinear dynamics of electroconvective flows: From equilibria to Hopf bifurcation and chaos","authors":"Zhe Feng , Pedro A. Vázquez , Mengqi Zhang","doi":"10.1016/j.apm.2025.116680","DOIUrl":"10.1016/j.apm.2025.116680","url":null,"abstract":"<div><div>This work investigates the bifurcation and chaos in 2-D electroconvective (EC) flows of a dielectric liquid confined between two infinite parallel plates subjected to an electric potential difference. To further characterise its nonlinear dynamics, we compute the lower-branch unstable equilibrium solutions in the EC flow using the Jacobian-free Newton-Krylov method with a pseudo-arclength continuation technique and study their perturbative dynamics by the global linear stability analysis. These lower-branch unstable solutions are shown to act as edge states that delineate the initial conditions leading either to the hydrostatic state or to the upper-branch stable solutions. As the electric Rayleigh number <em>T</em> (measuring the strength of the electric field) increases, the electric Nusselt number Ne for these solutions decreases and the so-called charge-void region shrinks. Beyond the linear instability, an optimal horizontal wavelength corresponding to the strongest electric transport is identified among the upper-branch solutions. The upper-branch solution will undergo a Hopf bifurcation with the increase of <em>T</em>. The onset of Hopf bifurcation is accurately determined by the global linear stability analysis and this bifurcation is found to be of a supercritical nature. A larger mobility ratio <em>M</em> (quantifying the charge mobility) increases the value of the threshold for the Hopf bifurcation. When <em>T</em> further increases, the EC flow becomes chaotic, which can transiently visit two- and four-roll structures. In addition, the transition from periodic oscillation to chaos is found to be subcritical for the first time. We also find that the power spectra density in the chaotic EC flow decays following a power law with the exponent around 7, which is consistent with the experimental observation. The investigation of the nonlinear EC flow in this work may be helpful for a more complete understanding of its nonlinear dynamics.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116680"},"PeriodicalIF":4.4,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731461","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}
Pub Date : 2025-12-09DOI: 10.1016/j.apm.2025.116669
Daniel O. Martinez-Quezada , Cristián E. Cortés , Antonio Mauttone , Marcela A. Munizaga
Public transport plays a vital role in societal well-being and climate resilience. Battery Electric Vehicles (BEVs), while central to decarbonizing transit fleets, introduce operational challenges, including limited range and reliance on charging infrastructure. This study addresses the Electric Transit Network Design and Frequency Setting Problem (E-TNDFSP) by integrating both user and operator perspectives into a multi-objective framework, solved using the ϵ-constraint method and a Non-dominated Sorting Genetic Algorithm II (NSGA-II). NSGA-II performs comparably to the ϵ-constraint method on small instances and demonstrates scalability in real-world applications, such as in the city of Rivera, Uruguay. Hypervolume indicators confirm consistent improvements across generations, with relative gains above 60 % beyond 100 generations in the Mandl instance. Results show that fleet requirements for BEVs increase by up to 71 % under depot charging to maintain the same service level as diesel fleets. However, this increase can be reduced to 42 % through opportunity charging supported by 70 chargers. Energy consumption and network resilience metrics reveal critical trade-offs among fleet size, charging infrastructure, and user cost, offering data-driven insights for infrastructure planning. The findings support the viability of NSGA-II as a robust decision-making tool in electric transit systems.
{"title":"A multi-objective optimization approach for the electric transit network design and frequency setting problem","authors":"Daniel O. Martinez-Quezada , Cristián E. Cortés , Antonio Mauttone , Marcela A. Munizaga","doi":"10.1016/j.apm.2025.116669","DOIUrl":"10.1016/j.apm.2025.116669","url":null,"abstract":"<div><div>Public transport plays a vital role in societal well-being and climate resilience. Battery Electric Vehicles (BEVs), while central to decarbonizing transit fleets, introduce operational challenges, including limited range and reliance on charging infrastructure. This study addresses the Electric Transit Network Design and Frequency Setting Problem (E-TNDFSP) by integrating both user and operator perspectives into a multi-objective framework, solved using the ϵ-constraint method and a Non-dominated Sorting Genetic Algorithm II (NSGA-II). NSGA-II performs comparably to the ϵ-constraint method on small instances and demonstrates scalability in real-world applications, such as in the city of Rivera, Uruguay. Hypervolume indicators confirm consistent improvements across generations, with relative gains above 60 % beyond 100 generations in the Mandl instance. Results show that fleet requirements for BEVs increase by up to 71 % under depot charging to maintain the same service level as diesel fleets. However, this increase can be reduced to 42 % through opportunity charging supported by 70 chargers. Energy consumption and network resilience metrics reveal critical trade-offs among fleet size, charging infrastructure, and user cost, offering data-driven insights for infrastructure planning. The findings support the viability of NSGA-II as a robust decision-making tool in electric transit systems.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116669"},"PeriodicalIF":4.4,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731677","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}
Pub Date : 2025-12-09DOI: 10.1016/j.apm.2025.116681
Zhi Zhou , Can Wang , Haozhan Ma , Bocheng An , Linheng Li , Yuan Zheng , Chongyu Bao , Xu Qu , Bin Ran
As a major challenge to the modern traffic, traffic oscillation has drawn much research attention. With the emergence of connected and automated vehicle technology in the recent decade, numerous efforts have been made to optimize the car-following control strategy of connected and automated vehicle in order to mitigate the formation of traffic oscillations and alleviate the impact of “stop-and-go” traffic waves. Based on the platoon-based adaptive cruise control strategy for connected and automated vehicle platoon under leader following information flow topology presented in our previous study, this paper proposed a modified platoon-level cooperative adaptive cruise control strategy for connected and automated vehicle platoon under dynamic leader following information flow topology regulated by the optimal sub-platoon formation. By optimizing the feedforward mechanism of acceleration output of the leader vehicle in the platoon and dynamically adjusting the information flow topology of platoon, the proposed strategy can maximize the effect of oscillation mitigation along the platoon. With a series of frequency-domain and time-domain performance indicators, the numerical simulation experiments verify that the proposed strategy is substantially superior to the existing car-following strategies, in terms of mitigating traffic oscillations. It is also validated the robustness and generalizability of the proposed strategy when adopted in the large-scale mixed traffic flow under a variety of traffic condition, demonstrating its prominent performance on oscillation mitigation in the circumstances with high market penetration rates, low traffic flow speeds, and low-frequency oscillations.
{"title":"Mitigating traffic oscillations through connected and automated vehicle control: a platoon-level cooperative adaptive cruise control strategy with optimal sub-platoon formation","authors":"Zhi Zhou , Can Wang , Haozhan Ma , Bocheng An , Linheng Li , Yuan Zheng , Chongyu Bao , Xu Qu , Bin Ran","doi":"10.1016/j.apm.2025.116681","DOIUrl":"10.1016/j.apm.2025.116681","url":null,"abstract":"<div><div>As a major challenge to the modern traffic, traffic oscillation has drawn much research attention. With the emergence of connected and automated vehicle technology in the recent decade, numerous efforts have been made to optimize the car-following control strategy of connected and automated vehicle in order to mitigate the formation of traffic oscillations and alleviate the impact of “stop-and-go” traffic waves. Based on the platoon-based adaptive cruise control strategy for connected and automated vehicle platoon under leader following information flow topology presented in our previous study, this paper proposed a modified platoon-level cooperative adaptive cruise control strategy for connected and automated vehicle platoon under dynamic leader following information flow topology regulated by the optimal sub-platoon formation. By optimizing the feedforward mechanism of acceleration output of the leader vehicle in the platoon and dynamically adjusting the information flow topology of platoon, the proposed strategy can maximize the effect of oscillation mitigation along the platoon. With a series of frequency-domain and time-domain performance indicators, the numerical simulation experiments verify that the proposed strategy is substantially superior to the existing car-following strategies, in terms of mitigating traffic oscillations. It is also validated the robustness and generalizability of the proposed strategy when adopted in the large-scale mixed traffic flow under a variety of traffic condition, demonstrating its prominent performance on oscillation mitigation in the circumstances with high market penetration rates, low traffic flow speeds, and low-frequency oscillations.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116681"},"PeriodicalIF":4.4,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731467","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}
Pub Date : 2025-12-09DOI: 10.1016/j.apm.2025.116686
Hongtai Xie , Hong Wang
In order to guarantee the operational safety of next-generation high-speed trains (HSTs) equipped with aerodynamic lift wings (ALWs) under gusty conditions, this study proposes a method for calculating the time-dependent aerodynamic loads and dynamic load functions of trains in dynamic gust environments. This approach is based on the vehicle-track coupling dynamics theory and employs multibody system dynamics simulation techniques. To this end, simulations were conducted to evaluate the dynamic response of the train-track system and the derailment safety margin for ALW-equipped HSTs under various operational conditions, including different wind speeds, wind direction angles, train speeds, and their arbitrary combinations. The study revealed that the wheel unloading ratio and overturning coefficient serve as critical indicators for assessing operational safety and derailment safety criteria during lift control under gust loads. In light of the aforementioned findings, the critical operating speeds for ensuring the safety of lift control were ascertained to be 150.5 km/h, 207.7 km/h and 300.0 km/h for HSTs equipped with ALW operating under crosswind gusts of 22 m/s, 18 m/s and 14 m/s, respectively. Concurrently, it is imperative to enhance the standardization and quantification of the impact of maximum lateral roll displacement and acceleration on the operational safety of lift control systems. In the context of crosswind conditions, with a train velocity of 200 km/h and a maximum wind speed of 20 m/s, the maximum body displacement attained a value of 0.290 m, representing a 16% increase in comparison with the prototype train (PT). Concurrently, the maximum instantaneous acceleration exhibited an increase exceeding 50%.
{"title":"Impact of aerodynamic lift wings on operational safety of high-speed trains through lift regulation and control in gusts","authors":"Hongtai Xie , Hong Wang","doi":"10.1016/j.apm.2025.116686","DOIUrl":"10.1016/j.apm.2025.116686","url":null,"abstract":"<div><div>In order to guarantee the operational safety of next-generation high-speed trains (HSTs) equipped with aerodynamic lift wings (ALWs) under gusty conditions, this study proposes a method for calculating the time-dependent aerodynamic loads and dynamic load functions of trains in dynamic gust environments. This approach is based on the vehicle-track coupling dynamics theory and employs multibody system dynamics simulation techniques. To this end, simulations were conducted to evaluate the dynamic response of the train-track system and the derailment safety margin for ALW-equipped HSTs under various operational conditions, including different wind speeds, wind direction angles, train speeds, and their arbitrary combinations. The study revealed that the wheel unloading ratio and overturning coefficient serve as critical indicators for assessing operational safety and derailment safety criteria during lift control under gust loads. In light of the aforementioned findings, the critical operating speeds for ensuring the safety of lift control were ascertained to be 150.5 km/h, 207.7 km/h and 300.0 km/h for HSTs equipped with ALW operating under crosswind gusts of 22 m/s, 18 m/s and 14 m/s, respectively. Concurrently, it is imperative to enhance the standardization and quantification of the impact of maximum lateral roll displacement and acceleration on the operational safety of lift control systems. In the context of crosswind conditions, with a train velocity of 200 km/h and a maximum wind speed of 20 m/s, the maximum body displacement attained a value of 0.290 m, representing a 16% increase in comparison with the prototype train (PT). Concurrently, the maximum instantaneous acceleration exhibited an increase exceeding 50%.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"154 ","pages":"Article 116686"},"PeriodicalIF":4.4,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731468","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}
Pub Date : 2025-12-09DOI: 10.1016/j.apm.2025.116672
Saeedeh Qaderi , Nicholas Fantuzzi , J.N. Reddy
Advances in composite structures with improved mechanical properties enable a better balance between strength and weight, benefiting high-demand fields like civil and aerospace engineering. Higher-order theories effectively model such structures but are often complex owing to the multitude of parameters involved. To ease this burden, internal constraints are introduced, but they can complicate numerical methods like the finite element method (FEM) by requiring higher-order shape functions. Driven by the challenges of finite element modeling for constrained composites, this study focuses on the thermal buckling behavior of higher-order GPLRC plates. Internal constraints in higher-order plate theories are introduced by employing the Lagrange Multiplier Method (LMM) and the Penalty Method (PM). These methods disable the interpolation of displacement parameters using Lagrange shape functions with C0 continuity, ensuring simple shape functions, a well-posed weak formulation, compatibility with standard FEM software, and avoiding the need for complex formulations in a classical finite element framework. The theoretical formulation of the GPLRC laminate plate is derived based on the General Third-order Shear deformation plate Theory (GTST). The Halpin-Tsai model and rule of mixtures are used to determine the laminated plate material properties. Four GPL distribution patterns across composite layers are analyzed for their impact on laminate buckling behavior. The LMM and PM results are systematically compared by varying parameters such as element count, GPL weight fraction, and geometrical dimensions, demonstrating the effectiveness and accuracy of constraint enforcement techniques in FEM-based thermal buckling analysis of composite plates. The study provides a robust framework for modeling complex composite structures, enabling efficient solutions in computational environments.
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