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Analysis of vibration signal transmission and power loss in complex nonlinear dynamics interfaces within gearbox systems

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mechanical systems and Signal Processing 2025年 234卷

作者： Wei, Chaohu Shi, Jianghai Sun, Yachao Yang, Yang Du, Minggang Cao, Hongrui National Key Lab of Aerospace Power System and Plasma Technology Xi'an Jiaotong University Xi'an710049 China School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China China North Vehicle Research Institute Beijing100072 China

Nonlinear dynamic interfaces, such as bearings, splines, and gears, play important roles in mechanical systems. During the operation of gearbox transmission systems, vibration signals and power are attenuated and dissipated by friction, damping, and other nonlinear factors present in various dynamic interfaces. This paper focuses on quantifying the influence of nonlinear factors on vibration signal transmission and power loss in a gearbox transmission system with multiple special dynamic interfaces, including spiral bevel gears, spline connections, and embedded bearing interfaces. Firstly, dynamic models for the embedded bearing, spline, and spiral bevel gears are developed, quantifying the impact of nonlinear factors such as stiffness, damping, friction, and clearance on vibration signal transmission. Next, a gearbox transmission system model incorporating these nonlinear interfaces is presented, considering the coupling effects between different dynamic interfaces, and is validated experimentally. A novel method for quantifying vibration signal transmission is proposed, enabling the evaluation of signal transmission and the influence of nonlinear factors on signal attenuation within the system. The nonlinear factors that mainly affect the attenuation of vibration signal transmission are identified. Finally, a new method for calculating the power transmission rate based on gear meshing forces is put forward, accounting for the coupling effects of nonlinear interfaces. The power transmission rates for the embedded bearing and spline are calculated, and the effects of friction and damping are analyzed. © 2025 Elsevier Ltd

关键词： Vibration analysis

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A novel fatigue life prediction method for the laser deposition repaired TA15 component with annealing heat treatment

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engineering Failure Analysis 2025年 177卷

作者： Zhou, Song Qian, Zhaoxing Zhang, Zhenjun Bai, Xin School of Mechatronics Engineering Shenyang Aerospace University Shenyang110136 China Shenyang110136 China Shenyang Aircraft Design and Research Institute Shenyang110135 China School of Mechanical Engineering and Automation Northeastern University 110819 China Institute of Metal Research Chinese Academy of Sciences 72 Wenhua Road Shenyang110016 China

The fatigue properties are very important for the laser deposition repaired TA15 component with annealing heat treatment (named as LDR & AHT TA15) used in aerospace. However, the current fatigue life prediction methods can not predict the fatigue life of the LDR & AHT TA15 component due to the limitation of the fatigue damage model or the experimental data accuracy. To predict the fatigue life of the LDR & AHT TA15 component, a new fatigue prediction model with considering annealing heat treatment (named as FLRA model) is established based on the fatigue physics of the microstructure transformation. Then a new fatigue life prediction method (named as EFL method) based on the FLRA model is proposed. By comparing with the experimental fatigue life of the LDR & AHT TA15 and the traditional method, the FLRA model and the EFL method show high accuracy and strong robustness (i.e. the location of stress concentration, the location of the maximum cumulative damage and the accumulation of the damage value). Furthermore, the parameters of the FLRA model are illustrated in microstructure fatigue physics. © 2025 Elsevier Ltd

关键词： Fatigue damage

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Metalized plastic current collectors: Bridge to high energy density reconciling high safety for lithium-ion batteries

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Journal of Energy Storage 2025年 125卷

作者： Lu, Xianhang Hao, Ming Fu, Yunhe Xie, Mingming Su, Shaokang Hu, Yuxiang Bian, Xin Xie, Yuanhua Ba, Yaoshuai Zhao, Xinying Du, Xuefeng Chen, Zhengwei Ba, Dechun Liu, Kun School of Mechanical Engineering and Automation Northeastern University Shenyang110819 China Vacuum Science and Aerospace Engineering Research Center Northeastern University Shenyang110819 China Key Laboratory of Advanced Functional Materials College of Materials Science and Engineering Beijing University of Technology Beijing100124 China Institute of Fluid Engineering Zhejiang University Hangzhou310027 China School of Equipment Engineering Shenyang Ligong University Shenyang110159 China Co. Ltd. Shenyang110122 China

The energy density of mainstream lithium-ion batteries (LIBs) has nearly reached theoretical limits due to the growing demand for new energy vehicles. However, the LIBs continue to struggle with meeting the requirements of applications. Increasing energy density typically involves raising the nickel content and charging cut-off voltage, these strategies can compromise the structural stability of cathode and the electrochemical stability of electrolyte, thereby increasing the risk of battery fires. The challenge of balancing high energy density with high safety remains a significant barrier to the development of LIBs. The metalized plastic current collector (MPCC), with its sandwich-like structure composed of "conductive layer-support layer-conductive layer", offers a potential solution. The MPCCs' low thermal deformation temperature and plasticity mismatch with electrode materials allow it to disrupt continuous short-circuit states in extreme conditions, preventing explosions. Additionally, the MPCCs could pull "flameproof, lightweight, thinning, and low-cost" all together, making it a feasible route for large-scale production to co-enhance energy density and safety of LIBs. Currently, on the eve of scaling and standardization, the new structure of MPCCs poses new challenges, particularly in the preparation process and equipment. This review delves into the structure, performance, application, and preparation status of MPCCs. It highlights the explosion-proof mechanism, process route, and coating equipment, summarizes the key challenges in MPCCs' application and preparation while exploring the prospects in next-generation battery systems. Additionally, the review discusses the modification strategies for MPCCs and provides an outlook on their scalability and future integration with advanced battery systems. © 2025 Elsevier Ltd

关键词： Lithium-ion batteries

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Gas turbine harmonic detection and modal identification based on underdetermined blind source separation

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Journal of Sound and Vibration 2025年 613卷

作者： Song, Chao Hu, Jianxiong Cheng, Wei Bo, Bicheng Yang, Mingsui Chen, Xuefeng Yan, Liqi Qiao, Baijie Gao, Lin Huang, Hai Yin, Jialu National Key Lab of Aerospace Power System and Plasma Technology Xi'an Jiaotong University Xi'an710049 China School of Mechanical Engineering Xi'an Jiaotong University Xi'an710049 China Shenyang Engine Research Institute Aero Engine Corporation of China Liaoning Province Shenyang110015 China

In gas turbine operational modal parameter identification, traditional methods like operational modal analysis or underdetermined blind source separation (UBSS) struggle with underdetermined time-delay mixture and harmonic interference. Based on the signal sparsity in the energy domain, this paper proposes a novel method based on improved UBSS with binary time-frequency masking (BTFM). First, signals are transformed to the time-frequency domain, and then to the energy domain by integrating over time. And peak frequency points are detected frequency energy sum curve from each channel. Second, to distinguish source signals, cosine distances between peak frequency points and other ones are calculated, and BTFM is constructed. Third, source signals are recovered and padding lines are added to reduce boundary effects. Finally, to detect harmonic components in the source signals, the probability density and kurtosis of each signal are calculated. Based on the separated modal response signals, the modal frequency of each order is identified, and the modal modes are determined using the mixing matrix. The effectiveness of the proposed method is validated through comprehensive analysis on a simulation system, a three-rotor test bench, and gas turbine datasets. Results show that it outperforms existing methods in achieving more accurate and reliable modal identification under harmonic interference. The proposed method facilitates operational modal identification and condition monitoring for large-scale equipment such as gas turbines, thereby providing guidance for structural optimization and vibration/noise reduction. © 2025

关键词： Modal analysis

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Line laser measurement, evaluation and utilization of holistic gear deviations

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Measurement: Sensors 2025年

作者： Shi, Zhaoyao Sun, Yanqiang Yu, Bo Wang, Xiaoyi Zhao, Baoya Beijing Engineering Research Center of Precision Measurement Technology and Instruments Beijing University of Technology Beijing China School of Construction Machinery Shandong Jiaotong University Shandong Jinan China Henan Key Laboratory of Mechanical Design and Transmission System Henan University of Science and Technology Luoyang China School of Mechatronics Engineering North China Institute of Aerospace Engineering Langfang China

The measurement of holistic gear deviations (HGD) is a fast-developing field of gear measurement technology in recent years. Line laser measurement is an effective approach to measure the HGD, and is beginning to be applied. However, compared with the mature conventional gear measurement based on "point" and "line" measurement, the holistic gear deviations measurement is imperfect, especially in acquisition, evaluation and utilization. This paper introduces the line laser measurement model of HGD and puts forward the solutions to the problems such as the determination of the position and attitude parameters of the laser sensor, the influence of the incident angle of the measuring light, and the occlusion of the adjacent gear teeth in the measurement. The representation method of the three-dimensional deviations of the tooth flank is illustrated. According to the HGD, a unified model for calculating the elemental deviations of the gear, such as the involute and helix, is found. The HGD evaluation system is established by means of the statistical analysis method. The full use of the HGD is explored from two aspects of gear process error analysis and gear performance prediction, including tooth flank twist analysis, calculation of gear integrated error (GIE) and transmission error (TE), matching method of large batch of gears, etc. The analysis system of HGD is built on the cloud platform. The measurement, evaluation and utilization of HGD are the key technologies of the next generation gear measurement. © 2025

关键词： Metrology Gear Holistic gear deviations

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Bifurcation analysis of an opinion dynamics model coupled with an environmental dynamics

arXiv

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arXiv 2025年

作者： Couthures, Anthony Bizyaeva, Anastasia Varma, Vineeth S. Franci, Alessio Morărescu, Irinel-Constantin Université de Lorraine CNRS CRAN NancyF-54000 France Automation Department Technical University of Cluj-Napoca Memorandumului 28 Cluj-Napoca400114 Romania Sibley School of Mechanical and Aerospace Engineering Cornell University United States Department of Electrical Engineering and Computer Science University of Liege WEL Research Institute Wavre Belgium

We consider an opinion dynamics model coupled with an environmental dynamics. Based on a forward invariance argument, we can simplify the analysis of the asymptotic behavior to the case when all the opinions in the social network are synchronized. Our goal is to emphasize the role of the trust given to the environmental signal in the asymptotic behavior of the opinion dynamics and implicitly of the coupled system. To do that, we conduct a bifurcation analysis of the system around the origin when the trust parameter is varying. Specific conditions are presented for both pitchfork and Hopf bifurcation. Numerical illustration completes the theoretical findings. © 2025, CC BY-SA.

关键词： Bifurcation (mathematics)

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The DRTS-Net Framework: Enhanced Probabilistic Health Perception for Wind Turbine Bearings Under Complex Operating Conditions With Improved Interpretability

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IEEE Transactions on Instrumentation and Measurement 2025年 74卷

作者： Yang, Tongguang Li, Guanchen Huo, Jinzhao Li, Xiaoyong Zhou, Xianwen Han, Qingkai Northeastern University School of Mechanical Engineering and Automation Shenyang110819 China Johns Hopkins University Department of Mechanical Engineering BaltimoreMD21218 United States Foshan University School of Mechatronic Engineering and Automation Foshan528225 China SCNU Environmental Research Institute Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety MOE Key Laboratory of Theoretical Chemistry of Environment South China Normal University School of Environment Guangzhou510006 China SCNU Qingyuan Institute of Science and Technology Innovation Company Ltd. Qingyuan511517 China Northeastern University Key Laboratory of Vibration and Control of Aero-Propulsion System Ministry of Education Shenyang110819 China

Health perception in mechanical systems is a crucial aspect of prognostics and health management (PHM). Deep learning models have been successfully applied to health perception in wind turbine bearings. However, due to the time-varying, redundant, and noisy characteristics of time-series data representing bearing wear, existing models face significant challenges, particularly in terms of generalization and interpretability. Moreover, although most current models have provided health perceptions, they overlook the strong stochastic nature of bearing degradation data, and thus fail to deliver reliable predictions of uncertainty information. To address these technical challenges, this study introduces a novel Deep residual temporal-spatial framework (DRTS-Net) for probabilistic health perception of wind turbine bearing wear states. This article creatively designs spatiotemporal information fusion module for extracting features from bearing degradation data. Inspired by improvements in residual network structures, the DRTS-Net integrates an attention mechanism and a soft thresholding mechanism from the deep residual shrinkage network to optimize the feature extraction process. This integration aims to mitigate the interference from minor redundant features in the degradation data. The framework incorporates Gaussian process regression in the output layer to yield the probability distribution of single-health perception values for bearing features. A comparative study was conducted using the same bearing health state dataset against current mainstream deep learning methods for bearing health assessment. Results demonstrate that the proposed DRTS-Net achieves superior performance in high-precision health perception, high-reliability probabilistic health perception. © 1963-2012 IEEE.

关键词： Stochastic systems

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Durable Ag-Coated Micro-Crack Velcro Electrode for Hi-Fi Bioelectric Signals in Hairy Areas

Durable Ag-Coated Micro-Crack Velcro Electrode for Hi-Fi Bio...

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IEEE International Conference on Micro Electro mechanical systems

作者： Jun Guo Kang Fu Zimo Zhang Ruiyu Bai Xuanqi Wang Kai Xue Huazhen Chen Le Li Huijing Hu Minghao Wang Honglong Chang Bowen Ji Unmanned System Research Institute Northwestern Polytechnical University China National Key Laboratory of Unmanned Aerial Vehicle Technology Integrated Research and Development Platform of Unmanned Aerial Vehicle Technology Northwestern Polytechnical University China Ministry of Education Key Laboratory of Micro/Nano Systems for Aerospace School of Mechanical Engineering Northwestern Polytechnical University China Institute of Medical Research Northwestern Polytechnical University China MOE Engineering Research Center of Smart Microsensors and Microsystems College of Electronics and Information Hangzhou Dianzi University China

ISBN: (数字)9798331508890

ISBN: (纸本)9798331508906

This paper reports a conductive Velcro electrode with micro-cracks for the first time. The laser-induced micro-cracks increase the surface area of Velcro hooks and facilitate the adhesion of more silver particles. A cluster of Nylon-Ag hook are durable with repeated mechanical compression and multiple washing. After 100 times of compression, the plastic deformation is less than 23 μm (<10%). The impedance (@10 Hz) of the Velcro electrode is still 2.6% lower than the AgCl electrode after washing for 3 times. The resilient conductive hooks can effectively penetrate through thick hair for hi-fi bioelectric signal acquisition, compared with commercial AgCl electrodes.

关键词： Electrodes Hair Micromechanical devices Surface impedance Silver Deformation Adhesives Surface emitting lasers Plastics Impedance

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Macro and micro delamination detection in adhesive structures: A synthesized linear and nonlinear air-coupled ultrasonic technique

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Ultrasonics 2025年 154卷 107675页

作者： Shan, Shengbo Li, Zheng Kong, Qingzhao Cheng, Li School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai200092 China Shanghai Institute of Aircraft Mechanics and Control Shanghai200092 China COMAC Shanghai Aircraft Manufacturing Co. Ltd China College of Civil Engineering Tongji University Shanghai200092 China Department of Mechanical Engineering The Hong Kong Polytechnic University Kowloon Hong Kong Hong Kong Branch of National Rail Transit Electrification and Automation Engineering Technology Research Center The Hong Kong Polytechnic University Kowloon Hong Kong

Adhesive structures are widely used in industries. During manufacturing and operation, both macro and micro delamination between different materials or layers may occur within these structures. Despite the practical use of air-coupled ultrasonic testing (ACUT) techniques for detecting such delamination, the interaction mechanisms between elastic waves generated by air-coupled transducers and these two types of delamination have not yet been fully understood. Additionally, there is a lack of accurate identification methods for either macro or micro delamination. To address these issues, this study proposes a synthesized linear and nonlinear ACUT approach for detecting and identifying both types of delamination in adhesive structures. Using finite element simulations with a coupled ACUT model, the study thoroughly examines the interaction between ACUT-induced elastic waves and the delamination types. The results show that macro delamination causes wave reflection and transmission, while micro delamination leads to contact acoustic nonlinearity. The proposed method is validated through experiments and shown to be effective for detecting and identifying both types of delamination. The results of the study contribute to the advancement of ACUT theory and applications, elucidate complex wave features and pave the way for more sophisticated non-destructive evaluation techniques. © 2025 Elsevier B.V.

关键词： Acoustic emission testing

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Curvature-property coupling governed heat transfer deterioration in supercritical helically coiled tubes: Mechanistic insights and mitigation strategies via structural parametrization

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International Journal of Thermal Sciences 2025年 215卷

作者： Chang, Fucheng Xin, Jiaxing Wu, Xiaoyi Li, Liwei Li, Huixiong Zhu, Yanlin National Key Lab of Aerospace Power System and Plasma Technology School of Mechanical Engineering Xi'an Jiaotong University Xi'an 710049 China China Special Equipment Testing and Research Institute Beijing 100029 China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China Shanghai Nuclear Engineering Research & Design Institute Co. Ltd Shanghai 200233 China

The unique thermo-hydrodynamic coupling phenomena in the helically coiled tube (HCT) handling supercritical fluids present both opportunities and challenges for next-generation compact heat exchangers. While the pronounced thermophysical property variations near pseudo-critical temperatures (T_pc) and curvature-induced secondary flows synergistically enhance heat transfer coefficient (HTC), their nonlinear coupling mechanisms may unexpectedly provoke severe heat transfer deterioration (HTD). Through systematic numerical investigations, this study reveals that circumferential wall temperature inhomogeneity (CWTI) exhibits an inverted N-shaped evolution, providing valuable insights for thermal homogenization design near T_pc. The secondary flow Reynolds number (Se), quantifying secondary flow intensity, shows a monotonic increase with decreasing coil diameter (D_c) or inner diameter (D_i), reaching saturation in high-enthalpy regions. Notably, CWTI demonstrates non-monotonic behavior, achieving minimum values near T_pc before manifesting distinct rebound characteristics near T_pc conditions. Parametric analysis establishes that: (1) Elevating heat flux (q) increases Se, reducing D_c boosts it by 50.3 %, and decreasing D_i raises it by 60.0 %. (2) HTD predominantly initiates at the outer wall under high-q conditions, with D_c reduction achieving HTD suppression and 26.9 % enhancement in the local HTC;(3) Reducing the D_i results in a reduction of maximum CWTI by 22.5 %–28.6 %, suggesting that structural parametrization effectively mitigates wall temperature non-uniformity, thus suppressing the HTD. While centered on supercritical water, the dimensionless scaling relationships demonstrate extendibility to other media, with the curvature-property coupling mechanism both elucidating fundamental interactions and guiding robust heat exchanger design. © 2025 Elsevier Masson SA

关键词： Heat transfer deterioration Helically coiled tube Structural parametrization Supercritical fluid Thermo-hydrodynamic coupling

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