Applied Mathematical Modelling最新文献

{"title":"Investigation of a tuned clutch inerter mass damper for vibration reduction: An ANN-based harmonic balance method and parameter optimization","authors":"Yingjie Kang ,&nbsp;Zeyu Zhang ,&nbsp;Xinyu Zhang ,&nbsp;Zewen Zhang ,&nbsp;Qingkuan Liu","doi":"10.1016/j.apm.2025.116321","DOIUrl":"10.1016/j.apm.2025.116321","url":null,"abstract":"<div><div>This paper investigates a novel vibration reduction device, the tuned clutch inerter mass damper (TCIMD), which utilizes a clutch inerter damper as its primary energy dissipation mechanism. Due to the nonlinearity of the clutch inerter, an approximate analytical solution for the steady-state response of a single-degree-of-freedom primary structure equipped with the TCIMD is derived using the harmonic balance method (HBM). Additionally, an artificial neural network-based harmonic balance method (ANNHB) is proposed. The precise integration method (PIM), known for its accuracy and efficiency, is employed for comparison, offering a comprehensive evaluation of the accuracy of both the analytical solutions and the new methods from time-domain and frequency-domain perspectives. Numerical optimization techniques, based on the H^∞ and H² criteria, are used to optimize both the frequency ratio and clutch inerter ratio of the TCIMD. Fitting formulas for these optimal parameters are subsequently developed to simplify their application. The vibration control performance of the TCIMD is evaluated under various conditions, including harmonic excitation, free vibration, seismic excitation, and wind excitation. The results indicate that the approximate analytical solution based on HBM and the solution using ANNHB closely match the numerical solution obtained through the PIM and Newmark-Beta methods. This analytical solution is useful for analyzing the dynamic characteristics and parameter optimization design of the TCIMD. Furthermore, the fitting formulas for the optimal frequency and clutch inerter ratios effectively capture the influence of the damping ratio on the primary structure, with errors of &lt;5.3 % compared to the numerically exact solution. The TCIMD demonstrates significant damping effects under harmonic excitation, free vibration, and wind excitation, although its performance under seismic excitation exhibits considerable variability.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116321"},"PeriodicalIF":4.4,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665024","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":"Coordinated robust control and energy consumption analysis of active suspension based on bionic reference model and nonlinear extended state observer","authors":"Wenbin Liu ,&nbsp;Mingde Gong ,&nbsp;Xindi Xu ,&nbsp;Chaoyang Ji ,&nbsp;Dingxuan Zhao ,&nbsp;Hao Chen","doi":"10.1016/j.apm.2025.116314","DOIUrl":"10.1016/j.apm.2025.116314","url":null,"abstract":"<div><div>This paper proposes a coordinated robust control method for the nonlinear active suspension system based on a bionic reference model and disturbance observer. Inspired by the biological structure of the cheetah's legs and tail, a bionic reference model with nonlinear quasi-zero stiffness characteristics is designed, which has better vibration isolation performance. A new nonlinear function is designed to balance the contradiction between vehicle ride comfort and suspension displacement, in the case of small suspension deflection, the control objective focuses on ride comfort, and with the increase of suspension displacement, the control objective is gradually transformed to avoid suspension displacement exceeding the constraint range of the structure. Then a nonlinear extended state observer is designed to estimate the internal uncertain parameters and external unknown disturbances of the suspension system. Furthermore, a robust tracking controller is designed to ensure that the sprung mass displacement tracks the ideal trajectory, and the asymptotic stability of the system is proved based on Lyapunov theory. The simulation results show that compared with passive suspension, the vertical acceleration under three road excitations is reduced by 78.63 %, 83.07 %, and 76.43 %, respectively. Compared with the ESOT controller, the control energy consumption under three road excitations is reduced by 43.23 %, 51.54 %, and 55.95 %, respectively, and can ensure that the suspension displacement is always within the constraints of the structure. In addition, the problem that the suspension displacement cannot be restored to zero after the tire passes through the steps in the existing control method is solved.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116314"},"PeriodicalIF":4.4,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664998","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 flexible model of ordered random variables for non-metallic inclusions in steels and related statistical inference","authors":"Stefan Bedbur ,&nbsp;Udo Kamps ,&nbsp;Anja Bettina Schmiedt","doi":"10.1016/j.apm.2025.116284","DOIUrl":"10.1016/j.apm.2025.116284","url":null,"abstract":"<div><div>In a data set of non-metallic inclusion sizes in samples from engineering steel, common order statistics fail to serve as a suitable model for ascendingly ordered measurements within single samples. Therefore, a flexible model of ordered random variables is proposed, which allows for changes of distributions described by model parameters. Joint maximum likelihood estimation of these parameters and the shape parameter of an underlying left-truncated Weibull distribution is considered, and a model test is developed for the null-hypothesis of common order statistics being an adequate model. To overcome small data situations, a link-function approach is examined in order to reduce the number of involved model parameters as well as to propose to use a link-function parameter as a material indicator. An asymptotic test is provided to check for the presence of a linear link function, and tests for hypotheses about two link-function parameters are studied. Moreover, the construction of simultaneous confidence regions for the link-function parameters as well as of confidence bands for the entire graph of the link function are presented. Throughout, the findings are applied to the real metallurgical data set. Similar problems and data structures arise in other fields of material science and applications such as geology.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116284"},"PeriodicalIF":4.4,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665015","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":"Optimal periodic review order-up-to policy in a single-vendor multi-retailer cold chain with continuous multi-stage quality degradation","authors":"G. Chen ,&nbsp;M.I.M. Wahab ,&nbsp;L. Fang","doi":"10.1016/j.apm.2025.116323","DOIUrl":"10.1016/j.apm.2025.116323","url":null,"abstract":"<div><div>This study presents a cost optimization model for a two-echelon cold chain involving a single vendor and multiple retailers with stochastic product demand. The vendor and retailers follow periodic review order-up-to policies, where the vendor’s review period is an integer multiple of each retailer’s review interval. Product quality degradation, influenced by storage time and temperature, is modeled using the non-Arrhenius equation and the global stability index method. Degradation begins at the vendor’s side and continues at the retailers’, necessitating a continuous modeling approach. An algorithm is developed to minimize the expected total cost and to determine the optimal decisions for the cold chain. The study explores various scenarios and their optimal solutions, highlighting the impact of storage time and temperature on quality degradation and cost efficiency. The findings demonstrate that periodic review order-up-to policies enhance cost efficiency and inventory management in cold chains, while controlling storage time and temperature is essential to mitigate quality degradation and maintain product integrity. A continuous degradation model provides a more accurate understanding of quality loss across multiple stages, enabling better decision-making. Scenario analysis helps identify cost-effective strategies tailored to specific supply chain conditions, and the proposed algorithm serves as a practical tool for managers to balance cost and quality in cold chain operations. This research advances cold chain management by integrating cost optimization with quality degradation modeling, offering actionable insights for improved replenishment strategies and operational decision-making.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116323"},"PeriodicalIF":4.4,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665014","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":"Vibration analysis of Y-shaped bifurcated beams with variable cross-sections under thermoelastic coupling effects","authors":"Zhi-Heng Xiao ,&nbsp;Zhi-Jian Li ,&nbsp;Hong-Liang Dai","doi":"10.1016/j.apm.2025.116312","DOIUrl":"10.1016/j.apm.2025.116312","url":null,"abstract":"<div><div>Y-shaped bifurcated beams are critical components in aerospace and civil engineering systems, where thermo-mechanical coupling significantly alters their vibration behavior. This investigation develops a semi-analytical model for wave propagation in variable cross-section Y-shaped bifurcated beams based on Timoshenko beam theory, integrating axial-transverse vibration coupling effects. The governing equations are derived using Fourier transforms and modal perturbation theory, with numerical methods addressing non-integrable coupling terms. Key findings include: 1) The proposed model outperforms conventional Euler and Timoshenko beam theories in accuracy by explicitly incorporating axial force effects induced by thermal loads; 2) Cross-sectional parameters (height/width) exhibit dual effects: height increases raise natural frequencies via bending stiffness, while width amplifies mass-induced damping in low-frequency regimes. Bifurcation angle variations critically influence higher-mode coupling; 3) Thermal loads induce linear response trends under minor temperature rises but follow Gaussian amplitude decay patterns under high thermal shocks; 4) Symmetrical bifurcation angles amplify full-spectrum responses, necessitating asymmetric designs to mitigate resonance risks. This work provides a theoretical framework for optimizing bifurcated structures in thermo-mechanical environments.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116312"},"PeriodicalIF":4.4,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665016","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":"Convolutional neural networks based on DNA molecular circuits and applications","authors":"Yanfeng Wang ,&nbsp;Fei Fan ,&nbsp;Junwei Sun ,&nbsp;Haojie Wang","doi":"10.1016/j.apm.2025.116288","DOIUrl":"10.1016/j.apm.2025.116288","url":null,"abstract":"<div><div>In this paper, the convolutional neural network is constructed based on the DNA strand displacement circuits and the commodity classification and risk prediction of esophageal cancer patients are completed on the basis of convolutional neural network. Firstly, DNA strand displacement switch molecules are used as unit components, and the design of various modular DNA operation units is realized, including multiplication operation unit, logical operation unit, addition and subtraction operation units. Secondly, the weighted sum module, pooling module, ReLU activation function module, and signal recovery module are constructed based on DNA operation units. In addition, the DNA multiplier operation unit, DNA addition and subtraction operation units are cascaded to construct a DNA molecular circuit that can achieve multi-input weighted sum calculation and convolution calculation. Finally, the classification neural network and risk prediction neural network are constructed based on convolutional neural network models. The robustness of this work is confirmed through numerical simulation ineisual DNA strand displacement, which combines the weight training values of the dataset. Our work has validated the complex information processing capabilities of DNA molecules, and has shown promising prospects in the field of biomedicine.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116288"},"PeriodicalIF":4.4,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634165","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 mixed shock model under various sources for multi-component systems with Gamma degradation process","authors":"Hao Lyu ,&nbsp;Hengxin Wei ,&nbsp;Hualong Xie ,&nbsp;Yimin Zhang","doi":"10.1016/j.apm.2025.116316","DOIUrl":"10.1016/j.apm.2025.116316","url":null,"abstract":"<div><div>Although recent studies have investigated multi-component systems operating in multi-source shock environments, significant gaps remain, particularly in modeling multiple shock mechanisms and capturing intermediate system states. This paper develops a mixed shock reliability model for multi-component systems subjected to dependent competing failure processes in environments with multiple shock sources. The model accounts for both hard and soft failures, incorporating various failure modes and system configurations, including series, parallel, and <em>k</em>-out-of-<em>n</em>: G systems. Hard failures are modeled using phase-type distribution combined with the finite Markov chain imbedding approach, while soft failures are described by Gamma processes. Reliability metrics are evaluated at both the component and system levels. A case study involving <strong>micro electromechanical system</strong> oscillators is presented to illustrate the applicability and effectiveness of the developed approach.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116316"},"PeriodicalIF":4.4,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144663558","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":"Reliability of two-stage competing failure systems with dynamic load adjustment","authors":"Qinglai Dong ,&nbsp;Yuepeng Zhang ,&nbsp;Ning Wang","doi":"10.1016/j.apm.2025.116303","DOIUrl":"10.1016/j.apm.2025.116303","url":null,"abstract":"<div><div>Many engineering systems are prone to failure due to the combined influence of internal degradation and external random shocks. In such systems, degradation progression exhibits explicit load dependence. Current reliability models often overlook the critical interactions between environmental variability and load-dependent failure mechanisms. This paper develops an integrated framework by combining a two-phase load adjustment policy that dynamically regulates production rates to control degradation rates and a delay time reliability model to incorporate environmental uncertainty. Theoretical analysis and numerical simulations demonstrate that the proposed strategy effectively optimizes periodic inspection intervals under varying load conditions and enables system adjustment to a low-load operational mode upon defect detection. This approach significantly reduces the long-term average maintenance cost arising from competing failure mechanisms. Implementation in an unmanned aerial vehicle (UAV) system demonstrates the model's practical effectiveness, achieving substantial operational cost savings compared to fixed-load strategies. The proposed methodology provides a decision-support tool for industrial systems requiring balanced production efficiency and reliability.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116303"},"PeriodicalIF":4.4,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679460","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 novel fractional grey forecasting model for high-tech industry growth trends","authors":"Sandang Guo ,&nbsp;Jing Jia ,&nbsp;Xu Han ,&nbsp;Shuaishuai Geng","doi":"10.1016/j.apm.2025.116307","DOIUrl":"10.1016/j.apm.2025.116307","url":null,"abstract":"<div><div>Accurate forecasting of the high-tech industry output assumes strategic significance in directing industrial transformation and upgrading in the context of sustainable economic growth. However, due to the inherent randomness, nonlinearity, and volatility of industrial system data, traditional forecasting models often struggle to accurately capture its complex dynamics. To address this, our paper proposes a novel grey Bernoulli model which syncretizes a fractional order accumulation operator and a power exponent term, achieving adaptability to nonstationary time series and ensures precise fitting of system dynamic trends. In terms of model optimization, this study reconstructs the objective function and employs the Particle Swarm Optimization algorithm to solve for optimal parameters and modeling sequences, thereby enhancing the model’s predictive accuracy. Additionally, the proposed model is applied to forecast the output value of high-tech the Manufacture of Electronic Equipment and Communication Equipment industry with different data characteristics, and its performance is compared with five existing models. The results demonstrate that the proposed model outperforms the comparative models in both simulation and prediction stages, exhibiting strong robustness. Based on these findings, the model is further utilized to forecast the output value of the high-tech industry across China and within its Beijing-Tianjin-Hebei region over the next three years, providing critical decision-making references for industrial policy formulation.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116307"},"PeriodicalIF":4.4,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665017","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":"Coaxial permanent magnetic coupling analysis based on physics-informed neural network with periodic fixed boundary conditions","authors":"Ran Wang ,&nbsp;Xiuhong Hao ,&nbsp;Liping Zhang ,&nbsp;Wenchao Wu ,&nbsp;Shubo Hou","doi":"10.1016/j.apm.2025.116301","DOIUrl":"10.1016/j.apm.2025.116301","url":null,"abstract":"<div><div>Permanent magnet coupling is commonly used in various industries, such as vessels, wind power, and electric vehicles, thus making the optimization of its key parameters crucial. Most current calculation methods rely on finite element analysis, whose accuracy depends greatly on mesh size and requires high-performance computers. Physics-informed neural network has demonstrated effectiveness in solving partial differential equations, but it fails to predict the key performance of permanent magnet coupling, since the periodic magnetic field cannot be predicted accurately. To address the above issue, a new boundary imposition method, named the periodic fixed boundary condition physics-informed neural network, is proposed for precise calculation of permanent magnet coupling key parameters. Comparisons with finite element method results showed that this method significantly improved prediction accuracy compared to traditional physics-informed neural networks, with magnetic field calculation errors below 5%. Transfer learning further validated its generalization capability by predicting torque at different relative angles, achieving computation time reduced to 1/6 of the original neural network's computation time. Overall, this study provides a more accurate and efficient method to analyze the key performance of permanent magnet coupling.</div></div>","PeriodicalId":50980,"journal":{"name":"Applied Mathematical Modelling","volume":"149 ","pages":"Article 116301"},"PeriodicalIF":4.4,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634123","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}