Efficiently generating high-fidelity initial excitations remains a challenge for multi-input multi-output (MIMO) time waveform replication (TWR) of non-stationary signals. To address this, this paper proposes an adaptive multistep estimation (AME) algorithm that produces high-fidelity initial excitations capable of direct use in TWR, eliminating the need for iterative experimental corrections. The algorithm maintains robustness against modeling errors and system resonances during estimation. It employs a frame-based recursive architecture that avoids computationally expensive high-dimensional matrix operations. This architecture enables automatic regularization within each computational frame for effective error control. An excitation space optimization strategy is used to distinguish between excitations and noise, ensuring that only mild regularization is needed and thus preventing over-smoothing. Additionally, a selective regularization strategy is proposed that leverages prior information to apply regularization solely to components not captured by the prior knowledge, thereby yielding estimates closer to the true values. The algorithm also provides autonomous quality monitoring through cross-frame semi-norm comparison, eliminating dependence on expert intervention or experimental validation. Numerical simulations and experimental results validate the effectiveness of the AME algorithm in achieving high-fidelity initial excitation estimation for MIMO TWR of non-stationary signals.
{"title":"A novel adaptive multistep estimation algorithm for generating initial excitations of multi-input multi-output time waveform replication of non-stationary signals","authors":"Yucheng Zhang , Siyu Ren , Huaihai Chen , Xudong He , Ronghui Zheng","doi":"10.1016/j.ymssp.2026.113981","DOIUrl":"10.1016/j.ymssp.2026.113981","url":null,"abstract":"<div><div>Efficiently generating high-fidelity initial excitations remains a challenge for multi-input multi-output (MIMO) time waveform replication (TWR) of non-stationary signals. To address this, this paper proposes an adaptive multistep estimation (AME) algorithm that produces high-fidelity initial excitations capable of direct use in TWR, eliminating the need for iterative experimental corrections. The algorithm maintains robustness against modeling errors and system resonances during estimation. It employs a frame-based recursive architecture that avoids computationally expensive high-dimensional matrix operations. This architecture enables automatic regularization within each computational frame for effective error control. An excitation space optimization strategy is used to distinguish between excitations and noise, ensuring that only mild regularization is needed and thus preventing over-smoothing. Additionally, a selective regularization strategy is proposed that leverages prior information to apply regularization solely to components not captured by the prior knowledge, thereby yielding estimates closer to the true values. The algorithm also provides autonomous quality monitoring through cross-frame semi-norm comparison, eliminating dependence on expert intervention or experimental validation. Numerical simulations and experimental results validate the effectiveness of the AME algorithm in achieving high-fidelity initial excitation estimation for MIMO TWR of non-stationary signals.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113981"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135218","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}
Pub Date : 2026-03-01Epub Date: 2026-02-09DOI: 10.1016/j.ymssp.2026.113978
Yuegang Luo, Ning Liu, Songsong Xiao, Wanlei Wang
Rolling bearings are assembled on the shaft through interference fit. The presence of shaft cracks directly affects bearing operation and may even induce defects. Conversely, bearing defects may also exacerbate shaft damage. Currently, research on the bearing defect-shaft crack coupled faults remains insufficient and requires further exploration. This paper proposes an inner raceway extension defect model that incorporates the motion trajectory of the rolling elements. A dynamic model of a rotor-bearing-pedestal system with bearing extension defect and shaft crack is established. The dynamic characteristics of defects, cracks, and coupled faults are systematically analyzed, and the coupling mechanism is further investigated. The simulation and experimental results indicate that for inner raceway defect-shaft crack coupled fault, an increase in crack depth amplifies the bearing fault characteristics, especially when the crack is located near the bearing support or at the midspan of the shaft. The extension of the defect also exacerbates the damage caused by the crack to the shaft. For outer raceway defect-crack coupled fault, shallow cracks suppress the bearing fault frequency. However, once the crack depth exceeds a certain threshold, this suppression transitions to amplification. Cracks located at the midspan of the shaft enhance the bearing fault characteristics. The extension of the outer raceway defect primarily affects the bearing fault frequency and the overall vibration amplitude. The findings of this study are expected to provide a valuable theoretical basis for diagnosing and predicting bearing defect-shaft crack coupled faults.
{"title":"Dynamic behaviors of a rolling bearing-rotor system with bearing extended defect and shaft crack: simulation and experimental investigation","authors":"Yuegang Luo, Ning Liu, Songsong Xiao, Wanlei Wang","doi":"10.1016/j.ymssp.2026.113978","DOIUrl":"10.1016/j.ymssp.2026.113978","url":null,"abstract":"<div><div>Rolling bearings are assembled on the shaft through interference fit. The presence of shaft cracks directly affects bearing operation and may even induce defects. Conversely, bearing defects may also exacerbate shaft damage. Currently, research on the bearing defect-shaft crack coupled faults remains insufficient and requires further exploration. This paper proposes an inner raceway extension defect model that incorporates the motion trajectory of the rolling elements. A dynamic model of a rotor-bearing-pedestal system with bearing extension defect and shaft crack is established. The dynamic characteristics of defects, cracks, and coupled faults are systematically analyzed, and the coupling mechanism is further investigated. The simulation and experimental results indicate that for inner raceway defect-shaft crack coupled fault, an increase in crack depth amplifies the bearing fault characteristics, especially when the crack is located near the bearing support or at the midspan of the shaft. The extension of the defect also exacerbates the damage caused by the crack to the shaft. For outer raceway defect-crack coupled fault, shallow cracks suppress the bearing fault frequency. However, once the crack depth exceeds a certain threshold, this suppression transitions to amplification. Cracks located at the midspan of the shaft enhance the bearing fault characteristics. The extension of the outer raceway defect primarily affects the bearing fault frequency and the overall vibration amplitude. The findings of this study are expected to provide a valuable theoretical basis for diagnosing and predicting bearing defect-shaft crack coupled faults.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113978"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146778","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}
Pub Date : 2026-03-01Epub Date: 2026-02-09DOI: 10.1016/j.ymssp.2026.113928
Ye Lu , Xiaomei Li , Zhijiang Xie , Haolan Jia , Zhenjun Su , Xiaoliang Hu
To investigate the coupling effects of clearance and flexible components on dynamic performance of pushrod-driven actuator, this study proposes a hybrid contact force model suitable for large loads with an adaptive restitution coefficient, and a modified transitional lubrication force model. Considering the influence of flexible components, a rigid-flexible coupling dynamics model of the actuator incorporating lubrication clearance is established. Subsequently, effects of clearance size, driving speed, dynamic viscosity and load on system’s dynamics and chaos are then analyzed. Finally, experimental validation confirms the model’s effectiveness. The results show that the choice of clearance size and drive speed significantly influences system stability, and that high dynamic viscosity lubricants can lower the output vibration frequency and amplitude. Under large loads, the lubricant film thickness at clearance approaches zero, intensifying clearance collisions and wear. This increases the output vibration frequency, and substantially reduces the lubricant’s mitigating effects on clearance and flexible factors. This study provides theoretical support for the design of high-performance rudder actuators.
{"title":"Rigid-flexible coupling modeling and nonlinear analysis of rudder actuator with lubrication clearance","authors":"Ye Lu , Xiaomei Li , Zhijiang Xie , Haolan Jia , Zhenjun Su , Xiaoliang Hu","doi":"10.1016/j.ymssp.2026.113928","DOIUrl":"10.1016/j.ymssp.2026.113928","url":null,"abstract":"<div><div>To investigate the coupling effects of clearance and flexible components on dynamic performance of pushrod-driven actuator, this study proposes a hybrid contact force model suitable for large loads with an adaptive restitution coefficient, and a modified transitional lubrication force model. Considering the influence of flexible components, a rigid-flexible coupling dynamics model of the actuator incorporating lubrication clearance is established. Subsequently, effects of clearance size, driving speed, dynamic viscosity and load on system’s dynamics and chaos are then analyzed. Finally, experimental validation confirms the model’s effectiveness. The results show that the choice of clearance size and drive speed significantly influences system stability, and that high dynamic viscosity lubricants can lower the output vibration frequency and amplitude. Under large loads, the lubricant film thickness at clearance approaches zero, intensifying clearance collisions and wear. This increases the output vibration frequency, and substantially reduces the lubricant’s mitigating effects on clearance and flexible factors. This study provides theoretical support for the design of high-performance rudder actuators.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113928"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146713","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}
Pub Date : 2026-03-01Epub Date: 2026-01-31DOI: 10.1016/j.ymssp.2026.113929
Ye-Wei Zhang , Ji Zhang , Jian Zang , Li-Qun Chen
Hygrothermal exposure significantly alters the dynamic characteristics of composite beam-plate frames supporting cryogenic hydrogen tanks. Accurate characterization of hygrothermal effects on structural dynamics is essential for ensuring safety and achieving lightweight designs of hydrogen-electric aircraft. This paper presents an analytical framework based on improved orthogonal polynomials within a Rayleigh-Ritz formulation to characterize the dynamic behavior of composite beam-plate coupled systems (CBPCSs) under the hygrothermal environment and elastic boundary constraints. By integrating Kirchhoff thin-plate theory with the Euler-Bernoulli beam assumption, the method yields closed-form expressions for the potential, kinetic, elastic, and hygrothermal potentials of the CBPCSs. Interfacial flexibility at laminate-beam-plate junctions is modeled via an equivalent spring system to capture elastic restraint effects. Validation against laboratory modal tests and high-fidelity finite-element simulations demonstrates excellent convergence and computational accuracy. Parametric analyses reveal how boundary stiffness, coupling interfaces, and hygrothermal conditions influence natural frequencies and mode shapes with nonlinear trends. This work presents a reliable theoretical approach for the vibration optimization and structural design of composite support frames in hydrogen-electric aircraft, with experimental and numerical validation confirming its applicability to practical engineering scenarios.
{"title":"Dynamic characteristics of composite beam-plate coupled structures under hygrothermal conditions for hydrogen-electric aircraft: analytical and experimental investigation","authors":"Ye-Wei Zhang , Ji Zhang , Jian Zang , Li-Qun Chen","doi":"10.1016/j.ymssp.2026.113929","DOIUrl":"10.1016/j.ymssp.2026.113929","url":null,"abstract":"<div><div>Hygrothermal exposure significantly alters the dynamic characteristics of composite beam-plate frames supporting cryogenic hydrogen tanks. Accurate characterization of hygrothermal effects on structural dynamics is essential for ensuring safety and achieving lightweight designs of hydrogen-electric aircraft. This paper presents an analytical framework based on improved orthogonal polynomials within a Rayleigh-Ritz formulation to characterize the dynamic behavior of composite beam-plate coupled systems (CBPCSs) under the hygrothermal environment and elastic boundary constraints. By integrating Kirchhoff thin-plate theory with the Euler-Bernoulli beam assumption, the method yields closed-form expressions for the potential, kinetic, elastic, and hygrothermal potentials of the CBPCSs. Interfacial flexibility at laminate-beam-plate junctions is modeled via an equivalent spring system to capture elastic restraint effects. Validation against laboratory modal tests and high-fidelity finite-element simulations demonstrates excellent convergence and computational accuracy. Parametric analyses reveal how boundary stiffness, coupling interfaces, and hygrothermal conditions influence natural frequencies and mode shapes with nonlinear trends. This work presents a reliable theoretical approach for the vibration optimization and structural design of composite support frames in hydrogen-electric aircraft, with experimental and numerical validation confirming its applicability to practical engineering scenarios.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113929"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095826","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}
Pub Date : 2026-03-01Epub Date: 2026-01-29DOI: 10.1016/j.ymssp.2026.113933
Haitao Xu , Shengxi Zhou
In nonlinear systems, the multistable potential function has been demonstrated to be an effective means to broaden the work frequency bandwidth. Taking the energy harvester as an example, the function can help it efficiently capture the broadband energy under low-level excitations. However, it is necessary to discuss the effect of asymmetry of the multistable potential function on nonlinear dynamics. Firstly, this paper designs the piecewise tristable potential function, which can produce three types of asymmetries. Secondly, according to tristable galloping-based energy harvesters, influence of asymmetries on their responses under harmonic excitation, and on the stochastic resonance phenomenon under harmonic and random excitations are investigated by numerical simulations. In addition, the phase trajectories, Poincaré maps and Lyapunov exponents are also employed to exam the system responses, such as the chaotic motion, quasi-periodic motion, and periodic motion. Thirdly, according to the experimental signal, the proposed signal enhancement methods based on the stochastic resonance of tristable galloping-based energy harvesters are successfully validated. The output signal-to-noise ratios are also calculated to compare their performance. Overall, this paper explores the effect of asymmetry on nonlinear dynamics, as well as the potential application in signal processing.
{"title":"Nonlinear dynamics of tristable galloping-based energy harvesters and their application in weak signal enhancement","authors":"Haitao Xu , Shengxi Zhou","doi":"10.1016/j.ymssp.2026.113933","DOIUrl":"10.1016/j.ymssp.2026.113933","url":null,"abstract":"<div><div>In nonlinear systems, the multistable potential function has been demonstrated to be an effective means to broaden the work frequency bandwidth. Taking the energy harvester as an example, the function can help it efficiently capture the broadband energy under low-level excitations. However, it is necessary to discuss the effect of asymmetry of the multistable potential function on nonlinear dynamics. Firstly, this paper designs the piecewise tristable potential function, which can produce three types of asymmetries. Secondly, according to tristable galloping-based energy harvesters, influence of asymmetries on their responses under harmonic excitation, and on the stochastic resonance phenomenon under harmonic and random excitations are investigated by numerical simulations. In addition, the phase trajectories, Poincaré maps and Lyapunov exponents are also employed to exam the system responses, such as the chaotic motion, quasi-periodic motion, and periodic motion. Thirdly, according to the experimental signal, the proposed signal enhancement methods based on the stochastic resonance of tristable galloping-based energy harvesters are successfully validated. The output signal-to-noise ratios are also calculated to compare their performance. Overall, this paper explores the effect of asymmetry on nonlinear dynamics, as well as the potential application in signal processing.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113933"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072595","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}
Pub Date : 2026-03-01Epub Date: 2026-02-03DOI: 10.1016/j.ymssp.2026.113969
Xiang Gao , Qiang Zhao , Hui Ming , Zihao Zhou , Junchuan Niu , Zhonglong Wang , Zhen Qin
In order to explore the vibration isolation performance of semi-active suspension based on self-powered Magneto-Rheological (MR) damper with interval uncertainty, the electromechanical coupling dynamic model of quarter vehicle suspension with key parameters perturbation is established. The vibration isolation capability is investigated in time and frequency domain with key parameters perturbation respectively. The non-probabilistic reliability of the proposed suspension is deduced by shortest distance method. The balance index reflecting the comprehensive performance of energy harvesting characteristic and vibration isolation capability simultaneously is proposed by dynamical programming theory. The adjustment of structural parameters of damper is much more effective to improve the comprehensive performance. The optimized key parameters are obtained by calculating the Nash equilibrium point of the balance index, meanwhile, the validation of the proposed optimized approach with NSGA-II algorithm is conducted. The optimized MR damper and energy harvesting part are fabricated and tested. The experimental results are similar to the simulating results, which indicates the effectiveness and correctness of the proposed optimized method.
{"title":"Vibration isolation capability with interval uncertainty and optimization of semi-active suspension based on self-powered magneto-rheological damper","authors":"Xiang Gao , Qiang Zhao , Hui Ming , Zihao Zhou , Junchuan Niu , Zhonglong Wang , Zhen Qin","doi":"10.1016/j.ymssp.2026.113969","DOIUrl":"10.1016/j.ymssp.2026.113969","url":null,"abstract":"<div><div>In order to explore the vibration isolation performance of semi-active suspension based on self-powered Magneto-Rheological (MR) damper with interval uncertainty, the electromechanical coupling dynamic model of quarter vehicle suspension with key parameters perturbation is established. The vibration isolation capability is investigated in time and frequency domain with key parameters perturbation respectively. The non-probabilistic reliability of the proposed suspension is deduced by shortest distance method. The balance index reflecting the comprehensive performance of energy harvesting characteristic and vibration isolation capability simultaneously is proposed by dynamical programming theory. The adjustment of structural parameters of damper is much more effective to improve the comprehensive performance. The optimized key parameters are obtained by calculating the Nash equilibrium point of the balance index, meanwhile, the validation of the proposed optimized approach with NSGA-II algorithm is conducted. The optimized MR damper and energy harvesting part are fabricated and tested. The experimental results are similar to the simulating results, which indicates the effectiveness and correctness of the proposed optimized method.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113969"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110165","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}
Pub Date : 2026-03-01Epub Date: 2026-02-03DOI: 10.1016/j.ymssp.2026.113951
Aniruddha Das , Ashish Pal , Satish Nagarajaiah , M. Mohamed Sajeer , Suparno Mukhopadhyay
Displacement plays a crucial role in structural health monitoring (SHM) and damage detection of structural systems subjected to dynamic loads. However, due to the inconvenience associated with the direct measurement of displacement during dynamic loading and the high cost of displacement sensors, the use of displacement measurements often gets restricted. In recent years, indirect estimation of displacement from acceleration and strain data has gained popularity. Several researchers have developed data fusion techniques to estimate displacement from acceleration and strain data. However, existing data fusion techniques mostly rely on system properties like mode shapes or finite element models and require accurate knowledge about the system for successful implementation. Hence, they have the inherent limitation of their applicability being restricted to relatively simple structures where such information is easily available. In this article, B-spline basis functions have been used to formulate a Kalman filter-based algorithm for acceleration and strain data fusion using only elementary information about the system, such as the geometry and boundary conditions, which is the major advantage of this method. Also, the proposed algorithm enables us to monitor the full-field displacement of the system online with only a limited number of sensors. The method has been numerically validated with both simple and complex numerical models. Later, the proposed data fusion technique was applied to an experimental benchmark test of a wind turbine blade under dynamic load to estimate the displacement time history. In all cases, the reconstructed displacement from strain and acceleration was found to match well with the response from the FE model.
{"title":"Signal-based online acceleration and strain data fusion using B-splines and Kalman filter for full-field dynamic displacement estimation","authors":"Aniruddha Das , Ashish Pal , Satish Nagarajaiah , M. Mohamed Sajeer , Suparno Mukhopadhyay","doi":"10.1016/j.ymssp.2026.113951","DOIUrl":"10.1016/j.ymssp.2026.113951","url":null,"abstract":"<div><div>Displacement plays a crucial role in structural health monitoring (SHM) and damage detection of structural systems subjected to dynamic loads. However, due to the inconvenience associated with the direct measurement of displacement during dynamic loading and the high cost of displacement sensors, the use of displacement measurements often gets restricted. In recent years, indirect estimation of displacement from acceleration and strain data has gained popularity. Several researchers have developed data fusion techniques to estimate displacement from acceleration and strain data. However, existing data fusion techniques mostly rely on system properties like mode shapes or finite element models and require accurate knowledge about the system for successful implementation. Hence, they have the inherent limitation of their applicability being restricted to relatively simple structures where such information is easily available. In this article, B-spline basis functions have been used to formulate a Kalman filter-based algorithm for acceleration and strain data fusion using only elementary information about the system, such as the geometry and boundary conditions, which is the major advantage of this method. Also, the proposed algorithm enables us to monitor the full-field displacement of the system online with only a limited number of sensors. The method has been numerically validated with both simple and complex numerical models. Later, the proposed data fusion technique was applied to an experimental benchmark test of a wind turbine blade under dynamic load to estimate the displacement time history. In all cases, the reconstructed displacement from strain and acceleration was found to match well with the response from the FE model.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113951"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110166","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}
Pub Date : 2026-03-01Epub Date: 2026-01-28DOI: 10.1016/j.ymssp.2026.113947
Jianfeng Tang , Yinglong Shang , Jiajian Meng , Junrong Li , Mingxu Xu , Yong Hu , Jianhai Zhang
Surface micro-cracks, a common and severe processing defect in CNC milling of high-performance components such as aero-engine turbine blades, act as stress concentration sites that drastically reduce the fatigue life of the component and threaten the structural safety of the engine. However, existing non-destructive testing techniques face challenges in being integrated into machine tools to achieve rapid, online, and quantitative in-situ detection of micro-defects on complex curved components. To address this, this paper proposes a novel in-situ detection paradigm based on a triboelectric nanogenerator (TENG), aiming to achieve high-precision quantitative inversion of the geometric parameters of micro-cracks on machined blade surfaces. The influence mechanism of crack width and depth on pulse amplitude and width was explained through systematic experimental research. Furthermore, by constructing multidimensional signal features that integrate time-domain and frequency-domain features, the coupling effects of width and depth can be decoupled. To achieve automated recognition, we constructed a hybrid deep learning model based on CNN-BiLSTM, which can autonomously mine the intrinsic correlation between spatiotemporal features and crack geometry parameters in the original signal, thereby synchronously outputting accurate predictions of width and depth. The experimental results show that the average absolute error of the model in predicting the width and depth of microcracks is as low as 0.0091 mm and 0.0047 mm, respectively, and the coefficient of determination (R2) is higher than 0.989. Furthermore, the potential of this method for identifying defects such as pitting, linear cracks, and network cracks has been further confirmed. This study not only confirms the enormous potential of TENG in intelligent manufacturing quality online monitoring, but also provides a solid technical path for the development of the next generation of intelligent integrated detection systems.
{"title":"A new method for quantitative evaluation of micro-cracks on turbine blade surfaces Fusing triboelectric sensing and hybrid deep learning","authors":"Jianfeng Tang , Yinglong Shang , Jiajian Meng , Junrong Li , Mingxu Xu , Yong Hu , Jianhai Zhang","doi":"10.1016/j.ymssp.2026.113947","DOIUrl":"10.1016/j.ymssp.2026.113947","url":null,"abstract":"<div><div>Surface micro-cracks, a common and severe processing defect in CNC milling of high-performance components such as aero-engine turbine blades, act as stress concentration sites that drastically reduce the fatigue life of the component and threaten the structural safety of the engine. However, existing non-destructive testing techniques face challenges in being integrated into machine tools to achieve rapid, online, and quantitative in-situ detection of micro-defects on complex curved components. To address this, this paper proposes a novel in-situ detection paradigm based on a triboelectric nanogenerator (TENG), aiming to achieve high-precision quantitative inversion of the geometric parameters of micro-cracks on machined blade surfaces. The influence mechanism of crack width and depth on pulse amplitude and width was explained through systematic experimental research. Furthermore, by constructing multidimensional signal features that integrate time-domain and frequency-domain features, the coupling effects of width and depth can be decoupled. To achieve automated recognition, we constructed a hybrid deep learning model based on CNN-BiLSTM, which can autonomously mine the intrinsic correlation between spatiotemporal features and crack geometry parameters in the original signal, thereby synchronously outputting accurate predictions of width and depth. The experimental results show that the average absolute error of the model in predicting the width and depth of microcracks is as low as 0.0091 mm and 0.0047 mm, respectively, and the coefficient of determination (R<sup>2</sup>) is higher than 0.989. Furthermore, the potential of this method for identifying defects such as pitting, linear cracks, and network cracks has been further confirmed. This study not only confirms the enormous potential of TENG in intelligent manufacturing quality online monitoring, but also provides a solid technical path for the development of the next generation of intelligent integrated detection systems.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113947"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071753","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}
The conditional random fields, by integrating on-site measured data information, provide a more practical and realistic tool for the engineering analysis of phenomena that exhibit random characteristics in both space and time across multiple dimensions. However, traditional simulation methods of conditional random fields still face significant computational bottlenecks when dealing with large-scale problems. To this end, this paper proposes a novel and efficient simulation technique for conditional random fields. The core of the proposed method lies in a refined approach to the Karhunen-Loève (K-L) expansion. Instead of approximating the full conditional covariance function, we directly compute or more accurately approximate the dominant eigenvalues and eigenfunctions of the theoretically exact conditional covariance function. This computation is achieved by using the Nyström approximation, conditional multivariate Gaussian distribution, and selected quadrature points. This streamlined process allows us to directly generate conditional random field realizations within the K-L expansion framework. The effectiveness and robustness of the proposed method are demonstrated through three numerical examples, including one-dimensional, two-dimensional, and large-scale three-dimensional conditional random field simulations. Results confirm that the proposed approach achieves an optimal balance between computational efficiency and simulation accuracy, providing a powerful tool for data-inform probabilistic engineering analysis.
条件随机场通过整合现场实测数据信息,为跨多维空间和时间随机性现象的工程分析提供了更为实用和现实的工具。然而,传统的条件随机场模拟方法在处理大规模问题时仍然面临着显著的计算瓶颈。为此,本文提出了一种新的、高效的条件随机场仿真技术。该方法的核心是对karhunen - lo (K-L)展开的一种改进方法。我们不是逼近完整的条件协方差函数,而是直接计算或更精确地逼近理论上精确的条件协方差函数的主导特征值和特征函数。这个计算是通过使用Nyström近似,条件多元高斯分布和选择的正交点来实现的。这个简化的过程允许我们在K-L扩展框架内直接生成条件随机场实现。通过一维、二维和大尺度三维条件随机场模拟,验证了该方法的有效性和鲁棒性。结果表明,该方法在计算效率和仿真精度之间达到了最佳平衡,为数据信息概率工程分析提供了有力的工具。
{"title":"Efficient simulation of conditional random fields by Karhunen–Loève expansion","authors":"Zhao Zhao , Teng-Fei Xu , Zhao-Hui Lu , Yan-Gang Zhao","doi":"10.1016/j.ymssp.2026.113938","DOIUrl":"10.1016/j.ymssp.2026.113938","url":null,"abstract":"<div><div>The conditional random fields, by integrating on-site measured data information, provide a more practical and realistic tool for the engineering analysis of phenomena that exhibit random characteristics in both space and time across multiple dimensions. However, traditional simulation methods of conditional random fields still face significant computational bottlenecks when dealing with large-scale problems. To this end, this paper proposes a novel and efficient simulation technique for conditional random fields. The core of the proposed method lies in a refined approach to the Karhunen-Loève (K-L) expansion. Instead of approximating the full conditional covariance function, we directly compute or more accurately approximate the dominant eigenvalues and eigenfunctions of the theoretically exact conditional covariance function. This computation is achieved by using the Nyström approximation, conditional multivariate Gaussian distribution, and selected quadrature points. This streamlined process allows us to directly generate conditional random field realizations within the K-L expansion framework. The effectiveness and robustness of the proposed method are demonstrated through three numerical examples, including one-dimensional, two-dimensional, and large-scale three-dimensional conditional random field simulations. Results confirm that the proposed approach achieves an optimal balance between computational efficiency and simulation accuracy, providing a powerful tool for data-inform probabilistic engineering analysis.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113938"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081371","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}
Reliable and efficient fault diagnosis of rolling element bearings is essential for condition monitoring of machinery operating in harsh environments, where signals are often contaminated by heavy-tailed, non-Gaussian impulsive noise. Bearing fault signatures exhibit both impulsiveness and cyclostationary behavior, making it challenging to prioritize one over the other when selecting the optimal frequency band for fault detection, especially amidst highly leptokurtic non-Gaussian noise. This paper addresses this question by evaluating the performance of the recently proposed Improved Envelope Spectrum via Feature Optimization-gram (IESFOgram) in the presence of heavy-tailed non-Gaussian noise. Moreover, the method is evaluated and compared against well established techniques, including the Fast Kurtogram (FK), the Infogram based on the Squared Envelope (Infogram-SE), and the Infogram based on the Squared Envelope Spectrum (Infogram-SES), highlighting the challenges of bearing diagnostics under the presence of non-Gaussian noise and the limitations of the mentioned state-of-the-art techniques. Using Monte-Carlo simulations and real-world industrial data from a copper ore crusher and a belt conveyor idler, it is clearly demonstrated that the IESFOgram outperforms the abovementioned state-of-the-art methods, detecting bearing defects earlier across different Signal-to-Noise Ratios (SNR), even in the presence of highly leptokurtic non-Gaussian noise.
{"title":"Efficient rolling element bearing fault diagnostics in the presence of highly leptokurtic non-Gaussian noise","authors":"Mahsa Yazdanianasr , Radosław Zimroz , Agnieszka Wyłomańska , Konstantinos Gryllias","doi":"10.1016/j.ymssp.2026.113852","DOIUrl":"10.1016/j.ymssp.2026.113852","url":null,"abstract":"<div><div>Reliable and efficient fault diagnosis of rolling element bearings is essential for condition monitoring of machinery operating in harsh environments, where signals are often contaminated by heavy-tailed, non-Gaussian impulsive noise. Bearing fault signatures exhibit both impulsiveness and cyclostationary behavior, making it challenging to prioritize one over the other when selecting the optimal frequency band for fault detection, especially amidst highly leptokurtic non-Gaussian noise. This paper addresses this question by evaluating the performance of the recently proposed Improved Envelope Spectrum via Feature Optimization-gram (IESFOgram) in the presence of heavy-tailed non-Gaussian noise. Moreover, the method is evaluated and compared against well established techniques, including the Fast Kurtogram (FK), the Infogram based on the Squared Envelope (Infogram-SE), and the Infogram based on the Squared Envelope Spectrum (Infogram-SES), highlighting the challenges of bearing diagnostics under the presence of non-Gaussian noise and the limitations of the mentioned state-of-the-art techniques. Using Monte-Carlo simulations and real-world industrial data from a copper ore crusher and a belt conveyor idler, it is clearly demonstrated that the IESFOgram outperforms the abovementioned state-of-the-art methods, detecting bearing defects earlier across different Signal-to-Noise Ratios (SNR), even in the presence of highly leptokurtic non-Gaussian noise.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"247 ","pages":"Article 113852"},"PeriodicalIF":8.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110172","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}