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Recent advancements of nonlinear dynamics in mode coupled microresonators:a review

Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 209-232页

作者： Xuefeng WANG Zhan SHI Qiqi YANG Yuzhi CHEN Xueyong WEI Ronghua HUAN Department of Engineering Mechanics MIIT Key Laboratory of Dynamics and Control of Complex SystemsNorthwestern Polytechnical UniversityXi’an 710129China Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou 310027China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710054China

Due to scale effects,micromechanical resonators offer an excellent platform for investigating the intrinsic mechanisms of nonlinear dynamical phenomena and their potential *** review focuses on mode-coupled micromechanical resonators,highlighting the latest advancements in four key areas:internal resonance,synchronization,frequency combs,and mode *** origin,development,and potential applications of each of these dynamic phenomena within mode-coupled micromechanical systems are investigated,with the goal of inspiring new ideas and directions for researchers in this field.

关键词： mode coupling micro-electro-mechanical system(MEMS)resonator nonlinear dynamics

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Mechanical and Geometric Properties of Nanosprings Based on Carbon Nanotubes with Dislocation Dipoles

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ACS Applied Nano Materials 2025年第18期8卷 9192-9200页

作者： Lei, Xiao-Wen Koyane, Jumpei Lu, Tong Matsuzaki, Kenichiro Yan, Yi Shi, Jin-Xing Fujii, Toshiyuki School of Materials and Chemical Technology Institute of Science Tokyo 2-12-1 Ookayama Meguro-ku Tokyo 152-8550 Japan Department of Engineering Mechanics MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi’an 710072 China Department of Production Systems Engineering and Sciences Komatsu University Nu 1-3 Shicyomachi Ishikawa Komatsu 923-8511 Japan

Carbon nanotubes (CNTs) are lightweight materials with excellent mechanical, electrical, and thermal conductivity, which make helical CNTs promising candidates for applications in mechanical components such as nanosprings. In this study, based on the continuous dislocation theory, we introduce dislocation dipoles into CNT with discrete crystal structures to design nanosprings, propose a method that integrates mechanics and geometry, and analyze the mechanical and geometric properties of nanosprings. In detail, this study investigated the feasibility of designing helical CNTs through spontaneous deformation induced by dislocation dipoles separated from Stone-Wales defects. Analytical models were constructed by systematically introducing dislocation dipoles into (4,4) CNTs of varying lengths. We combined mechanical and geometric methods, performed molecular dynamics simulations to obtain the stable structure of CNTs with dislocation dipoles, and employed differential geometry to investigate the Willmore energy of helically shaped CNTs. The results showed that when dislocation dipoles were introduced into straight CNTs, energy relaxation calculations demonstrated spontaneous deformation, leading to the formation of a spring-shaped CNT. The CNT length and dislocation type significantly affected the spring constant. Longer CNTs exhibited lower spring constants, and an increase in dislocation density led to a higher average potential energy. This study provides unique insights into the control of the CNT shape and mechanical and geometrical properties, contributing to the design of functional materials such as nanosprings. © 2025 The Authors. Published by American Chemical Society.

关键词： carbon nanotube dislocation dipoles geometric properties mechanical properties Nanospring

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Nonlinear Dynamic Modeling and Analysis of Rigid-Flexible Coupling Spacecrafts with Time-Varying Temperature Distribution

SSRN

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SSRN 2025年

作者： Zhao, Bingxin Gu, Xudong Hu, Rongchun Wu, Sihan Deng, Zichen Department of Engineering Mechanics Northwestern Polytechnical University Xi’an China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi’an China

When establishing the dynamic model of a rigid-coupled spacecraft, the traditional linear method requires the flexible structure to satisfy the small deformation assumption. However, the wide range of motion of the large spacecraft may lead to nonlinear deformation of the flexible structure. In this paper, the nonlinear dynamic model of the rigid-flexible coupling spacecraft is established during in-orbit operation. Firstly, the kinetic energy of the rigid-flexible spacecraft is derived by incorporating the nonlinear deformations with second-order coupling terms. Secondly, the time-varying temperature distribution along the thickness direction of the flexible structure is derived by using a one-dimensional thermal conduction equation. Then, the nonlinear time-varying coupled dynamics equations of the rigid-flexible coupling spacecraft are obtained by the Hamilton’s variational principle. The discrete equations are derived by using the assumed modal method (AMM). Finally, the results obtained through numerical calculations indicate that the nonlinear model accurately predicts the dynamical stiffening phenomenon as the attitude rotational velocity of the rigid hub increases. At the same time, the effects of the temperature, the orbital radius and structure size on the response amplitude of the spacecraft are obtained. © 2025, The Authors. All rights reserved.

关键词： Kinetics

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Expand the synchronization range of MEMS linear oscillators based on mode coupling and phase control

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Sensors and Actuators A: Physical 2025年 389卷

作者： Dai, Hongsheng Wang, Xuefeng Shi, Zhan Yang, Qiqi Xiao, Zunhao Liu, Zhiqiang Wei, Xueyong Huan, Ronghua Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang University Hangzhou China Department of Engineering Mechanics MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an China State Key Laboratory for Manufacturing Systems Engineering Xi'an Jiaotong University Xi'an China School of Instrument Science and Technology Xi'an Jiaotong University Xi'an China Huanjiang Laboratory Shaoxing China

Synchronization is a widespread phenomenon observed in both natural and societal systems. The advancement of MEMS technology has facilitated the study and application of synchronization, significantly enhancing the performance of MEMS sensors. However, the limited synchronization range of linear systems has restricted its broader application in sensor technologies. In this article, we propose a method to expand the synchronization range based on mode coupling and phase control. Theoretical derivations and experimental validations were conducted to demonstrate the effectiveness of the proposed approach. Experimental results reveal that the method achieves a synchronization range expansion of more than 50 times for both downward and upward frequency sweeps. Furthermore, the maintenance time of the synchronized state is significantly extended. This achievement is expected to provide a new solution for the application of synchronization-enhanced sensing in various fields, paving the way for improved sensor performance and broader applicability. © 2025 Elsevier B.V.

关键词： Synchronization

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A novel mode-I elliptic crack problem in one-dimensional hexagonal quasicrystals with the crack plane parallel to the quasi-periodic direction

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Applied Mathematical Modelling 2025年 146卷

作者： Liu, Haining Zheng, Ruifeng Wang, Yuzhe Deng, Zichen School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi'an710072 China Ministry of Industry and Information Technology Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an710072 China

This article studies a non-traditional elliptic crack problem in one-dimensional (1-D) hexagonal quasicrystals (QCs). The crack surface is parallel to the quasi-periodic axis of QCs and is subjected to a pair of uniform normal loadings. A unit point dislocation problem is considered first to derive the governing equation for the crack problem with an arbitrarily shaped planar crack, based on the potential theory method. The phonon-phason coupling field of the crack problem is expressed by simple integrals. The key fracture parameters, including the crack surface displacement (CSD) and stress intensity factor (SIF) are obtained. The analytical solutions are validated and the effects of eccentricity, phason field, crack orientation and material constants on the CSD and SIF are investigated. The results presented in this paper offer insights into the fracture mechanism of 1-D hexagonal QCs, while also providing a theoretical foundation for the design, optimization, and manufacture of QCs. © 2025 Elsevier Inc.

关键词： Quasicrystals

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Negative-pressure soft pneumatic actuators enabled by asymmetrically distributed bending units

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Extreme Mechanics Letters 2025年 77卷

作者： Fu, Zeyu Chen, Tianyu Zou, Haoran Zhu, Zhiwei Deng, Zichen Wang, Yifan School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi'an710072 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an710072 China School of Mechanical and Aerospace Engineering Nanyang Technological University Singapore 639798 Singapore State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

Soft pneumatic actuators are highly flexible and can adapt to complex environments, attracting significant attention for their ability to operate in settings where rigid actuators cannot. Most existing soft pneumatic actuators are powered by positive pressure, which has the disadvantage of volume increase during operation and risk of exploding under large pressures. In this study, we designed a new type of soft actuator by inducing asymmetric bending deformation throughout a holey structure under negative pressure. Using finite element analysis and a theoretical model, we studied the effects of various geometric parameters on the structure's bending behavior. We found that the displacement of the circle's center from the central axis is a parameter with the most significant impact on the bending behavior of the structure. By designing circular holes with offset from the central axis, the structure can bend toward the offset direction during subsequent bending deformation. Based on this deformation mechanism, we designed a soft gripper that bends upon actuation and effectively picks up objects. We further designed a bi-directional gripper that bends towards both sides and a circular gripper that contracts towards the center upon evacuation to hold objects. These soft grippers’ grasping capabilities are validated by experimental tests. Finally, by arranging the holes in a wavy pattern within the structure, we created a crawling robot that moves forward through cyclic negative pressure actuation. These findings highlight the potential of leveraging bending behaviors in asymmetrically distributed holey structures for the development of negative-pressure driven soft actuators and robots. © 2025 Elsevier Ltd

关键词： Pneumatic actuators

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Integrating artificial intelligence and machine learning with numerical simulation for enhanced thermal performance of ternary nanofluid

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Journal of Computational Design and Engineering 2025年第5期12卷 62-77页

作者： Hussain, Mohib Lin, Du Waqas, Hassan Al-Mdallal, Qasem M. School of Mathematics and Statistics Northwestern Polytechnical University Xi'an710072 China MIIT Key Laboratory of Dynamics and Control Complex System Northwestern Polytechnical University Xi'an710072 China School of Naval Architecture Ocean and Energy Power Engineering Wuhan University of Technology Wuhan Hubei430063 China Department of Mathematical Sciences UAE University Al-Ain15551 United Arab Emirates

The motivation for this investigation stems from a perceived gap in the vast literature on nanofluids, specifically in relation to their interactions with different surfaces and their numerical simulation. The main objective of this study is to effectively utilize novel machine learning (ML) and artificial intelligence (AI) techniques to investigate the thermal behavior of magnetohydrodynamic ternary nanofluids via an impermeable cylinder subject to activation energy and chemical reactions. We adopt the Levenberg-Marquardt algorithm with backpropagation artificial neural network technique (LMA-ANN), an AI-based scheme, to achieve this goal. The transition of governing equations to ordinary differential equations is accomplished through the use of similarity scaling. Obtained equations are then numerically evaluated using modified finite difference discretization (the Keller-Box approach). Regression scores equal to 1 indicate an excellent match between the numerical data and the predictions. The results demonstrate that temperature diminishes with the activation energy component, but it escalates with the chemical reaction. The activation energy parameter enhances both heat and mass transport processes. The results produced by this framework possess significant significance and usefulness in the field of biotechnology, drug delivery, cancer treatment, biological engineering, and bio-imaging. © 2025 The Author(s).

关键词： Activation energy

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Data-Driven Learning and control with Event-Triggered Measurements

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IEEE Transactions on Automatic control 2025年

作者： Feng, Shilun Shi, Dawei Chen, Tongwen Shi, Ling Beijing Institute of Technology State Key Laboratory of Intelligent Control and Decision of Complex Systems MIIT Key Laboratory of Servo Motion System Drive and Control School of Automation Beijing100081 China University of Alberta Department of Electrical and Computer Engineering EdmontonABT6G 1H9 Canada Hong Kong University of Science and Technology Department of Electronic and Computer Engineering Clear Water Bay Kowloon Hong Kong

Event-triggered control has attracted considerable attention for its effectiveness in resource-restricted applications. To make event-triggered control as an end-to-end solution, a key issue is how to effectively learn unknown system dynamics from event-triggered measurements and consequently, develop a learning-based event-triggered controller. Existing works learn system dynamics based on periodic time-triggered measurements, and it is yet to know how to learn a controller with performance guarantee based on event-triggered measurements. To address this issue, we consider the problem of learning an event-triggered state feedback controller for an unknown linear system based on event-triggered state measurements in this work. In particular, we first analyze the event-triggered measurements within a set-membership framework. We prove that the estimation error belongs to a bounded ellipsoid determined by the historical measurements and the event-triggering condition. Subsequently, we demonstrate that all admissible systems compatible with the collected data samples can be explicitly represented in the form of quadratic matrix inequalities using the state estimates. With the acquired set of admissible systems, a co-design problem for the data-driven controller and event-triggering condition is solved using the linear matrix inequality technique, with guaranteed closed-loop stability and L2-gain performance. Finally, numerical examples and comparisons are provided to illustrate the effectiveness of the proposed event-triggered learning and control approach. © 1963-2012 IEEE.

关键词： Networked control systems

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Higher-order interactions induce stepwise explosive phase transitions

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Physical Review E 2025年第2期111卷 024303-024303页

作者： Xueqi Li Palash Kumar Pal Youming Lei Dibakar Ghosh Michael Small School of Mathematics and Statistics Northwestern Polytechnical University Xi'an 710072 China Physics and Applied Mathematics Unit Indian Statistical Institute 203B. T. Road Kolkata 700108 India Ministry of Industry and Information Technology Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'an 710072 China Complex Systems Group Department of Mathematics and Statistics The University of Western Australia Crawley WA 6009 Australia Mineral Resources CSIRO Kensington WA 6151 Australia

In recent studies, it has been established that higher-order interactions in coupled oscillators can induce a process from continuous to explosive phase transition. In this study, we identify a phase transition, termed the stepwise explosive phase transition, characterized by the emergence of multiple critical phase plateaus in a globally frequency-weighted coupled pendulum model. This transition bridges the continuous and explosive phase transitions, arising from a delicate balance between attractive higher-order interactions and repulsive pairwise interactions. Specifically, the stepwise explosive phase transition occurs when the higher-order coupling is moderate, neither large nor small, while the pairwise interactions remain repulsive. Our analysis shows that stronger attractive higher-order interactions necessitate weaker repulsive pairwise interactions, leading to partial frequency locking among oscillators and triggering the stepwise transition. We construct an analytical framework using self-consistent equations to provide an approximation of the steady-state behavior. This study uncovers an alternative pathway to the desynchronization, and it provides additional insights into the phase transitions in coupled dynamical networks.

关键词： Pendulums

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Analysis of the optimal target node to reduce seizure-like discharge in networks

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Chinese Physics B 2024年第5期33卷 712-720页

作者：闫璐瑶张红慧孙中奎 School of Mathematics and Statistics Northwestern Polytechnical UniversityXi'an 710129China MIIT Key Laboratory of Dynamics and Control of Complex Systems Xi'an 710129China

Network approaches have been widely accepted to guide surgical strategy and predict outcome for epilepsy *** study starts with a single oscillator to explore brain activity,using a phenomenological model capable of describing healthy and epileptic *** ictal number of seizures decreases or remains unchanged with increasing the speed of oscillator excitability and in each seizure,there is an increasing tendency for ictal duration with respect to the *** underlying reason is that the strong excitability speed is conducive to reduce transition behaviors between two attractor ***,the selection of the optimal removal node is estimated by an indicator proposed in this *** show that when the indicator is less than the threshold,removing the driving node is more possible to reduce seizures significantly,while the indicator exceeds the threshold,the epileptic node could be the removal ***,the driving node is such a potential target that stimulating it is obviously effective in suppressing seizure-like activity compared to other nodes,and the propensity of seizures can be reduced 60%with the increased stimulus *** results could provide new therapeutic ideas for epilepsy surgery and neuromodulation.

关键词： epilepsy driving node epileptic node seizure regulation

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