Rongjian Sun , Conggan Ma , Yuanyuan Li , Chuyo Kaku , Yanyan Wang , Yu Zhang , Zheming Wen
{"title":"Experiment-driven identification approach of anisotropic damping behaviors and theoretical modal dynamic modelling of electric motors","authors":"Rongjian Sun , Conggan Ma , Yuanyuan Li , Chuyo Kaku , Yanyan Wang , Yu Zhang , Zheming Wen","doi":"10.1016/j.ymssp.2025.112737","DOIUrl":"10.1016/j.ymssp.2025.112737","url":null,"abstract":"<div><div>The modal dynamic behavior of the electrical motors (EMs) is a key determinant in accurately predicting vibration and noise. The natural frequency determines the frequency of structural resonance noise, making it a subject of extensive research. Notwithstanding the significant contributions of the damping ratios to the noise amplitude, this factor remains underexplored in the research field. Essentially, the anisotropic material damping of stator cores and windings remains unstudied. To address the existing research deficiency, an experiment-driven approach for calculating the damping ratios is put forward. Firstly, a theoretical modal dynamic model of the coupled structure consisting of the stator core, winding, and casing is developed. In particular, the hysteresis damping theory is employed to take the material damping behavior into account. Accordingly, the effect of anisotropic material damping of the stator core and windings on the structural damping ratios is thoroughly investigated. Subsequently, the anisotropic material parameters (AMPs) and anisotropic damping parameters (ADPs) of stator cores and windings are identified based on the proposed theoretical models and modal experiments. Finally, Natural frequencies and damping ratios are calculated utilizing the identified AMPs and ADPs. The absolute errors of the damping ratios of the stator core and stator assembly are within 0.14%, and the absolute errors of the stator system are within 0.25%. The proposed approach is of great significance for analyzing and controlling structural resonance noise of the EMs.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"234 ","pages":"Article 112737"},"PeriodicalIF":7.9,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kaixin Shao , Zhijun Yao , Baiyang Shi , Yuhao Liu , Jian Yang
{"title":"Vibration energy transfer in nonlinear coupled near-identical systems","authors":"Kaixin Shao , Zhijun Yao , Baiyang Shi , Yuhao Liu , Jian Yang","doi":"10.1016/j.ymssp.2025.112786","DOIUrl":"10.1016/j.ymssp.2025.112786","url":null,"abstract":"<div><div>This study investigates the dynamic response and vibrational energy transfer characteristics of coupled near-identical systems, with a focus on coupled discrete oscillators and coupled cantilever beams. Using analytical approximations based on the averaging method and harmonic balance-alternating frequency time (HB-AFT), alongside numerical integration, the dynamic responses and vibration transfer behaviour are analysed. The influence of both linear and nonlinear coupling stiffness is thoroughly examined. Comprehensive experimental results and finite element analysis (FEM) are conducted, focusing on mode shape and frequency response under motion excitation. For the motion excitation analysis, our findings reveal that even minor variations in mass can disrupt symmetry, resulting in the emergence of an additional resonant peak and illustrating the unique frequency response behaviours of near-identical systems. Notably, power flow analysis indicates that energy is transferred from the lighter oscillator to the heavier one across different frequency ranges, with distinct patterns observed during both in-phase and out-of-phase oscillations. For the power transfer curves, both linear and nonlinear cubic coupling stiffness ratio controls the location of the second resonance frequencies. It is also shown that the second resonance peak bends to a higher frequency when the cubic stiffness ratio increases. The results offer valuable implications for the design and optimization of coupled systems in various engineering applications.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"234 ","pages":"Article 112786"},"PeriodicalIF":7.9,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integrating data-driven reduced order models with Kriging for efficient sensor placement and full-field prediction","authors":"Weizhuo Wang","doi":"10.1016/j.ymssp.2025.112760","DOIUrl":"10.1016/j.ymssp.2025.112760","url":null,"abstract":"<div><div>This paper presents a two-stage methodology for efficient and accurate full-field displacement reconstruction using sparse online measurements derived from high-resolution Digital Image Correlation (DIC) data. The proposed approach integrates Modal Order Reduction and Kriging-based Uncertainty Quantification to address challenges associated with high-dimensional data analysis in structural dynamics.</div><div>In the offline stage, Adaptive Geometric Moment Descriptor (AGMD)-based shape features are used to compress the high-dimensional dataset, identify modal properties, and estimate residual covariance structures. In the online stage, a sparse set of optimally placed sensors, determined via QR decomposition with pivoting, is employed to infer full-field responses through <em>Kriging interpolation</em>, which also provides predictive variances for uncertainty quantification.</div><div>The methodology was demonstrated on a curved plate under random excitation. The results show strong correlations between measured and reconstructed fields using AGMDs and successfully identify multiple full-field vibration modes. In the online stage, the Kriging-predicted full-field responses, informed by an empirically estimated covariance structure from the offline dataset, exhibited better accuracy compared to predictions made using the Generalised Least Squares method (GLS). Validation on temporal sampling data achieved a coverage probability of 94.34% at 95% confidence intervals, highlighting the method’s reliability and robustness.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"234 ","pages":"Article 112760"},"PeriodicalIF":7.9,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zihang Li , Haoze Wang , Xilong Ji , Chongyang Wang , Kexin Cao , Lihua Yang
{"title":"Dynamic modeling and study of slipping and friction characteristics of four-point contact ball bearings under the angular misalignment","authors":"Zihang Li , Haoze Wang , Xilong Ji , Chongyang Wang , Kexin Cao , Lihua Yang","doi":"10.1016/j.ymssp.2025.112800","DOIUrl":"10.1016/j.ymssp.2025.112800","url":null,"abstract":"<div><div>Four-Point Contact Ball Bearing (FPCBB) is utilized in aero-engines, wind power and industrial gearboxes due to its ability to withstand axial forces in both directions, its high-speed performance, and its space-efficient design. It has been demonstrated that the structural characteristics of multi-point contact have some advantages, and at the same time increase the friction between the balls and the raceways. In this study, a dynamic model of the FPCBB is developed by considering six degrees of freedom for the ball and cage, and five degrees of freedom for the inner ring, incorporating nonlinear collision and frictional interactions among components. The model accounts for potential multi-point contact between the ball and raceway, as well as the angular misalignment of the inner ring. The maximum error between the experimental and simulated cage speed is only 4.98%, confirming the model’s accuracy. Based on this model, the vibration response of the bearing under angular misalignment, along with frictional characteristics are analyzed. Structural optimization is then performed based on these results. Additionally, the effects of angular misalignment and axial preload are evaluated. The findings indicate that the maximum PV value in the main load area under fixed-pressure preload is approximately 70% of that under locating preload. This study is aimed to provide a theoretical foundation for understanding the dynamic characteristics of these bearings under angular misalignment and for parameter selection in practical service applications.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"234 ","pages":"Article 112800"},"PeriodicalIF":7.9,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep reinforcement learning-based trajectory planning for double pendulum cranes: Design and experiments","authors":"Weili Ding , Heng Zhang , Changchun Hua , Biao Lu","doi":"10.1016/j.ymssp.2025.112780","DOIUrl":"10.1016/j.ymssp.2025.112780","url":null,"abstract":"<div><div>Since cranes usually possess double pendulum dynamics, the mass of the payload often changes and there are frequently lifting/lowering operations simultaneously. Moreover, most crane systems are driven by motors, whose velocities and accelerations are often limited. To solve the above problems, this paper proposes a deep reinforcement learning (DRL) reference trajectory generation method based on virtual–physical joint training. Firstly, a DRL module based on deep deterministic policy gradient (DDPG), along with a double pendulum crane dynamic model and an adaptive controller, are established within the virtual environment for training the reference trajectory. When the reward reaches the threshold, the training is switched to the physical environment to further optimize the reference trajectory, realizing the swing suppression of the hook and the payload. In addition, to satisfy the performance of the drive motors, velocity and acceleration thresholds are set to constrain the performance of the drive motors. Finally, in view of the fact that the operation process of the double pendulum crane is divided into payload transportation and payload loading/unloading, an event-triggering mechanism is designed to switch different control policies in accordance with different operation processes, thus reducing the consumption of computing resources. Through experiments on the actual double pendulum crane and comparison with the existing reference trajectories and input shapers, the superiority of this method is demonstrated.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"234 ","pages":"Article 112780"},"PeriodicalIF":7.9,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenkun Guo , Duo Zhu , Guoqing Jiang , Junyuan Zheng , Yanxue Wang , Jihou Yang
{"title":"Wave propagation characteristics of controllable gyroscopic chiral metamaterials","authors":"Zhenkun Guo , Duo Zhu , Guoqing Jiang , Junyuan Zheng , Yanxue Wang , Jihou Yang","doi":"10.1016/j.ymssp.2025.112811","DOIUrl":"10.1016/j.ymssp.2025.112811","url":null,"abstract":"<div><div>This paper investigates the dispersion characteristics and wave propagation of triangular and concave hexagonal gyroscopic metamaterials. The theory derivations of the dispersion relations are presented and validated through numerical simulations. Group velocity, phase velocity, and wave transmission with different gyroscope torques are analyzed, revealing how the gyroscope torque influences the wave propagation characteristics in the triangular structures. The results indicate that the gyroscope torque breaks the time inverse symmetry, inducing chirality in the triangular structure, and wave predominantly propagates along the spring direction on both low and high frequency dispersion surfaces. On this basis, the concave hexagonal gyroscopic metamaterial is proposed by introducing a transverse long spring, which exhibits two geometric special nodes. Four distinct dispersion surfaces with unique propagation characteristics are generated in the analysis of wave propagation. It is found that the propagation intensity on the first and second dispersion surfaces is highly sensitive to the direction of the gyroscope torque, while wave propagation characteristics of the third and fourth dispersion surfaces exhibit an opposite relationship, in which the Dirac cone is discovered. These findings emphasize that varying the gyroscope torque can achieve the same wave propagation characteristics with different frequencies or change wave propagation with the same frequencies, offering valuable insights for designing metamaterial structures with precise torque distribution control.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"233 ","pages":"Article 112811"},"PeriodicalIF":7.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Nonlinear vibrations of cantilevered circular cylindrical shells partially filled with liquid presenting large-amplitude sloshing","authors":"Hamid Reza Moghaddasi , Marco Amabili","doi":"10.1016/j.ymssp.2025.112787","DOIUrl":"10.1016/j.ymssp.2025.112787","url":null,"abstract":"<div><div>While fully numerical studies on nonlinear sloshing of liquids in various elastic and rigid containers exist, analytical studies on partially filled circular cylindrical elastic shells are limited to small-amplitude (linear) sloshing of the free liquid surface. In this study, for the first time, large-amplitude nonlinear vibrations of thin elastic shells, with clamped-free (cantilevered) boundary conditions, are coupled to large-amplitude sloshing liquid. The shell is modeled according to the Flügge-Lur’e-Byrne nonlinear shell theory. The liquid velocity potential satisfies the Laplace equation in the domain, and nonlinear boundary conditions are imposed at the free sloshing surface. Using the Lagrange multipliers method to satisfy the nonlinear boundary conditions for the liquid, the Lagrange equations of the system are made stationary. The effects of the liquid level inside the shell and nonlinearity at the free surface are investigated through frequency–response curves around resonances. It was observed that the sloshing nonlinearity often intensifies the softening behavior of the system in comparison to linear sloshing, and an increase in the liquid level inside the shell can have the same effect. Also, in contrast to some literature, it was found that there is a significant difference between considering nonlinear or linear sloshing during large amplitude vibrations of the shell, even when the free-surface oscillation amplitude is small.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"233 ","pages":"Article 112787"},"PeriodicalIF":7.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Automated Operational Modal Analysis of self-excited vibrations in turning","authors":"Ali Ebrahimi-Tirtashi, Keivan Ahmadi","doi":"10.1016/j.ymssp.2025.112705","DOIUrl":"10.1016/j.ymssp.2025.112705","url":null,"abstract":"<div><div>Regenerative chatter is a prevalent issue in machining, stemming from the instability of self-excited vibrations within the tool or workpiece. Operational Modal Analysis (OMA) of the tool or workpiece vibrations during turning operations is an effective method to predict and mitigate chatter. However, it requires substantial input from an expert user, undermining its application in process monitoring.</div><div>This paper presents an Automated Operational Modal Analysis (AOMA) approach to eliminate user intervention from the online chatter prediction process. The proposed approach combines clustering algorithms with knowledge about the system’s underlying physics to eliminate spurious poles as well as those representing the undamped harmonic oscillations. As a result, the dominant pole of self-excited dynamics is identified automatically, quantifying the stability of process vibrations. The accuracy and effectiveness of the proposed method are validated through experiments and numerical simulations.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"233 ","pages":"Article 112705"},"PeriodicalIF":7.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian-Hao Wu , Jin-Shui Yang , Xue-Yi Zhang , Lan-Ling Fu , Shuang Li , Lin-Zhi Wu , Rüdiger Schmidt , Kai-Uwe Schröder
{"title":"A neural network-based air-coupled ultrasonic damage detection method for composite honeycomb sandwich structure","authors":"Jian-Hao Wu , Jin-Shui Yang , Xue-Yi Zhang , Lan-Ling Fu , Shuang Li , Lin-Zhi Wu , Rüdiger Schmidt , Kai-Uwe Schröder","doi":"10.1016/j.ymssp.2025.112789","DOIUrl":"10.1016/j.ymssp.2025.112789","url":null,"abstract":"<div><div>Fiber reinforced composites have been widely used due to their excellent mechanical properties and designability, but the damage forms of composite materials are more complex compared to metals. Regular non-destructive testing (NDT) is crucial to ensure the reliability of equipment during use. Air-coupled ultrasound testing (ACUT), which uses air as the coupling agent, has the advantages of non-contact, simple equipment, and no pollution, and is widely used in NDT of composite material structures. However, the difference in acoustic impedance between the specimen and air results in poor accuracy of ACUT detection, and the analysis of the results is influenced by the experience of the technical personnel. To address this issue, a neural network-based method for damage detection and imaging has been proposed. Firstly, ACUT was used to detect pre-embedded defects at different depths within the composite honeycomb sandwich structure, and the original ultrasonic signals were obtained. Then, based on the pattern of sudden changes in signal amplitude at the defect boundary, detailed signal classification and defect area division were carried out by superimposing the results of damage area judgment under different thresholds. Finally, the signals after augmentation were input into neural networks to identify the state of the structure, and the prediction results are output to a pixel matrix to form a detection image. The results demonstrate that the trained neural network has a high classification accuracy; Even when faced with unseen data, the network still has strong robustness and generalization. Compared with traditional methods, neural networks only require A-scan signals to achieve state prediction, without the need for signal comparison in different states and relying on human experience, which can effectively improve recognition efficiency and reliability.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"233 ","pages":"Article 112789"},"PeriodicalIF":7.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shijie Wang , Jianfent Tao , Qinchent Jiang , Wei Chen , Chengliang Liu , Pengcheng Xia
{"title":"A degradation assessment method for industrial robot in flexible manufacturing systems based on multiple physics-informed neural network","authors":"Shijie Wang , Jianfent Tao , Qinchent Jiang , Wei Chen , Chengliang Liu , Pengcheng Xia","doi":"10.1016/j.ymssp.2025.112793","DOIUrl":"10.1016/j.ymssp.2025.112793","url":null,"abstract":"<div><div>With the expansion of industrial robot applications, degradation monitoring is valuable for manufacturing systems. The article develops a framework to predict the remaining useful life (RUL) of industrial robots, which is called Physical-Informed Channel-Attention-Inception-Unet (PICAIU), it can be used to evaluate the reducer degradation. In order to improve the training efficiency and prediction accuracy, it embeds knowledge of robot dynamics and servo controller into a data-driven neural network, adding channel-attention mechanism to the Inception-Unet to fuse motion and power feature, thereby obtaining accurate motor current estimates. Based on the aging experimental data of robot harmonic gear transmission, relevant life curves have been established, which can be used to evaluate other robots. We conducted a series of experiments to discuss the robustness and generalization of the proposed method. The ablation experiments showed that the introduction of physical information constraints improved training efficiency and convergence accuracy, effectively alleviating the sample size requirement of channel self-attention mechanism. The RUL prediction error was 26% lower than the best baseline model. Under the same batch size conditions, PICAIU only need 42% training rounds of the corresponding baseline model to let fitting error be lower than 10%, saving training time and sample costs significantly. Through cross validation with two robots, when generalizing from a rich dataset to poor dataset, the prediction error is only 6.4%, which has potential prospects in real industrial scenarios with relatively few samples.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"233 ","pages":"Article 112793"},"PeriodicalIF":7.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}