Mechanical Systems and Signal Processing最新文献

{"title":"Evaluation and optimal design of suspended backpacks considering the system instability introduced by load fluctuations","authors":"Tao Wang ,&nbsp;Jiahao Wu ,&nbsp;Jiahao Liu,&nbsp;Yang Liu,&nbsp;Jiejunyi Liang","doi":"10.1016/j.ymssp.2025.112701","DOIUrl":"10.1016/j.ymssp.2025.112701","url":null,"abstract":"<div><div>By introducing relative vertical motion to control the fluctuation of the mass center of the human-load bearing system, elastically suspended packs successfully achieve reducing metabolic cost in load carrying tasks. However, the theoretical optimal results of many of the proposed strategies are significantly different from the measured values. The reason is most existing methods are based only on the optimization of relative vertical motion control, failing to consider the significant impact of the vertical motion on the stability of human walking, which requires extra energy to compensate. To solve this problem, this paper constructed a human walking stability evaluation system based on moment analysis by analyzing the change rule of stability with gait cycle during human weight-bearing walking. In order to more accurately predict the effects of loaded exercise on human metabolic expenditure, a metabolic evaluation model was proposed that introduces a stability correction parameter by exploring the discrepancy between the traditional inverted pendulum energy expenditure prediction model and the experimental metabolic results. To design a novel optimal metabolic saving strategy, a passive elastically suspended backpack which can achieve different relative load motion states was designed, and biomechanical data of human motion were collected through walking experiments. The results show that the threshold for the motion amplitude ratio to ensure walking stability is α_thr ≈ 2, while the optimal metabolic amplitude ratio to minimize energy consumption is α_opt &lt; 1.5.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112701"},"PeriodicalIF":7.9,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806944","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":"Sound absorption estimation using the discrete complex image source method and array processing","authors":"Eric Brandão ,&nbsp;William D’Andrea Fonseca ,&nbsp;Paulo Henrique Mareze ,&nbsp;Carlos Resende ,&nbsp;Gabriel Azzuz ,&nbsp;João Pontalti ,&nbsp;Efren Fernandez-Grande","doi":"10.1016/j.ymssp.2025.112617","DOIUrl":"10.1016/j.ymssp.2025.112617","url":null,"abstract":"<div><div>Estimating the sound absorption of a material under realistic sound-field incidence conditions relies on accurately describing the measured data. Evidence suggests that modeling the reflection of impinging spherical waves is important, especially for compact measurement systems. This article proposes a method for estimating the sound absorption coefficient of a material sample by mapping the sound pressure, measured by a microphone array, to a distribution of monopoles, including the sound source and a series of complex image-sources. The proposed method is compared to modeling the sound field as a superposition of two sources (a monopole and an image source). The sound absorption measurement is tested with simulations of the sound field above infinite and non-locally reacting porous absorbers. The inverse problem estimations are compared to the classical plane-wave absorption coefficient and the one obtained by measuring the surface impedance when a spherical wave impinges on the absorber. Experimental analysis of two porous samples and one resonant absorber is also carried out in a laboratory. Two microphone arrays were tested with different apertures and number of sensors, and it was demonstrated that measurements are feasible even with the more compact array and for frequencies above 250 [Hz]. The discretization of the integral equation led to a more accurate reconstruction of the sound pressure and particle velocity at the sample’s surface. The resulting absorption coefficient agrees with the one obtained for spherical wave incidence, indicating that including the source and several complex image-sources is an essential feature of the sound field.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112617"},"PeriodicalIF":7.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806942","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":"Hybrid time–frequency method for vibration fatigue damage analysis under non-stationary non-gaussian random excitation","authors":"Wuyang Lei ,&nbsp;Yu Jiang ,&nbsp;Jinhao Zhang","doi":"10.1016/j.ymssp.2025.112630","DOIUrl":"10.1016/j.ymssp.2025.112630","url":null,"abstract":"<div><div>Accurate assessment of vibration fatigue life under non-stationary non-Gaussian excitations remains a critical challenge in mechanical system reliability. Traditional vibration fatigue frequency domain methods relying on stationary power spectral density (PSD) inherently overlook temporal variations and non-Gaussianity in stress responses, resulting in fatigue damage prediction errors that escalate exponentially with the fatigue exponent <em>b</em>. To address this limitation, this study proposes a hybrid time–frequency methodology that incorporates the amplitude-frequency response characteristics of the structure and reveals the critical role of excitation signal phase in influencing vibration fatigue life. The method not only resolves the inherent shortcomings of conventional spectral approaches but also enables inverse synthesis of excitation signals with controllable response characteristics. Numerical simulations and experimental validations demonstrate that the proposed approach significantly reduces in fatigue life predictions. Furthermore, the method serves a dual purpose: it advances vibration fatigue analysis for systems operating in complex service environments and introduces a novel approach for designing accelerated fatigue tests through tailored excitation signals. This work attempts to narrow the gap between non-stationary non-Gaussian vibration theory and practical engineering applications, providing a useful tool for reliability-driven mechanical design.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112630"},"PeriodicalIF":7.9,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806941","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":"Novel two-stage adaptive weight coefficients for Finite Element Model Updating of a cable-stayed bridge via sensitivity analysis and Kriging model","authors":"Shiqiang Qin ,&nbsp;Jialong Huang ,&nbsp;Shiwei Li ,&nbsp;Yunlai Zhou ,&nbsp;Magd Abdel Wahab","doi":"10.1016/j.ymssp.2025.112674","DOIUrl":"10.1016/j.ymssp.2025.112674","url":null,"abstract":"<div><div>The weight coefficients of the structural response residuals in an objective function are the key parameters affecting a Finite Element Model Updating (FEMU) results. Traditional equal weight methods cannot measure the importance and relative errors of different response residuals, resulting in low prediction accuracy of the updated Finite Element (FE) model. This study proposes a two-stage adaptive weight coefficient method according to the relative errors of the measured static displacements and modal frequencies. In the first stage, high weights are assigned to low-order frequencies and large displacements because they have higher accuracy and are less affected by environmental noises than high-order frequencies and small displacements. In the second stage, the weights for the responses with small relative errors are adaptively increased to reduce the prediction errors. This approach was comprehensively validated by numerical simulations of a damaged truss under various noise conditions and a full-scale cable-stayed bridge based on experimental measurements. Results indicate that the two-stage adaptive weight coefficients improve model updating accuracy and maintains robustness under various noise conditions compared to equal weight method. The updated FE model obtained from adaptive weight method for the cable-stayed bridge shows higher accuracy in predicting frequency and displacement than that obtained from equal weight method. After the model update, the maximum relative frequency error is reduced from −16.98% to −6.18%, and that of displacement is reduced from 17.85% to 5.87%.<!--> <!-->The two-stage adaptive weight coefficients improve the accuracy of FE model updating for bridge structures.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112674"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792308","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":"A joint sparse representation-based approach for anomaly rectification in extended-duration SHM systems with sensor networks","authors":"Xiaolei Xu ,&nbsp;Fucai Li ,&nbsp;Yue Hu ,&nbsp;Yanping Zhu","doi":"10.1016/j.ymssp.2025.112666","DOIUrl":"10.1016/j.ymssp.2025.112666","url":null,"abstract":"<div><div>In modern structural health monitoring (SHM) systems, the reliability of sensor networks plays a critical role in ensuring accurate defect detection and preventing potential failures in complex industrial applications. Sensor network-based SHM systems often suffer from challenges of transducer inconsistency and nonuniform degradation in extended-duration monitoring, leading to reduced detection accuracy and compromised system durability. This study proposes a framework that enhances system-level reliability by integrating Joint Sparse Representation (JSR) which propels outlier recognition and Distributed Compressed Sensing (DCS) which facilitates real-time signal reconstruction. By identifying abnormal sensors and reconstructing their signals, the framework improves inspection quality while restoring the functionality of the entire sensor network, which ensures the theoretical inspection accuracy and minimizes the risk of SHM system failure due to transducer degradation and inconsistency. Experimental results show that the proposed method achieves an average <em>F</em>₁-score improvement of 40.3 % (from 0.45 to 0.63) in defect detection and enhances signal-to-noise ratio (SNR) by up to 20.1 dB compared to the raw signal from inconsistent sensor networks. Whereas the cases studied are specific to ultrasonic guided wave SHM system, the proposed strategy is generic in systems with sensor networks. This framework contributes to more durable and reliable SHM practices by mitigating the risks of undetected defects and enhancing system reliability.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112666"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792354","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":"A novel vision-based dynamic identification method for coupler yaw angle of heavy-haul train through Separated Attention and Track Enhancement network","authors":"Letian Li,&nbsp;Shiqian Chen,&nbsp;Ruihan Xie,&nbsp;Kaiyun Wang,&nbsp;Wanming Zhai","doi":"10.1016/j.ymssp.2025.112690","DOIUrl":"10.1016/j.ymssp.2025.112690","url":null,"abstract":"<div><div>The coupler yaw angle (CYA) is an important indicator for assessing the safety and stability of heavy-haul train operation. Therefore, dynamic monitoring of CYA is crucial for ensuring the safe operation of the trains. However, the frequent and intense vibrations at the coupler during train running greatly affect the service life of the measuring device, leading to the instability of long-term monitoring of existing contact measurement methods. To address this issue, we first propose a novel vision-based dynamic identification method for heavy-haul train coupler yaw angle (CYA). Firstly, to solve the problem of cameras being affected by dazzling and dark lighting conditions when entering or exiting tunnels, we propose a data augmentation method tailored to the train running environment. Secondly, to address the issue of the target pins on the coupler being obscured by bolts, as well as the problem of false detection caused by external cables interfering, we combine the Separated and Enhancement Attention Module with a ByteTrack tracking method to propose a novel network structure named Separated Attention and Track Enhancement Network (SATE-Net). Furthermore, we propose a high-precision calibration method to calculate the final CYA value. Field tests are conducted to confirm the stability and accuracy of the proposed method in the quantitative identification of CYA.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112690"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792266","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":"Extrapolating from one: A pseudo multi-view fusion approach for enhanced out-of-distribution detection in fault diagnosis","authors":"Hairui Fang ,&nbsp;Haoze Li ,&nbsp;Han Liu ,&nbsp;Jialin An ,&nbsp;Jiawei Xiang ,&nbsp;Yanpeng Ji ,&nbsp;Yiwen Cui ,&nbsp;Fir Dunkin","doi":"10.1016/j.ymssp.2025.112661","DOIUrl":"10.1016/j.ymssp.2025.112661","url":null,"abstract":"<div><div>With outstanding performance, deep learning-based fault diagnosis methods have achieved many excellent results. However, these performances are fragile due to their high dependence on the assumption that data are independent and identically distributed (IID). Once the model diagnoses out-of-distribution(OOD) as an IID, it leads to unreliable diagnostic results. Although it is a reliable way to achieve OOD detection by information increment through multiple sensors, it cannot be applied in practice due to the requirement of single sensor in industrial scenarios. Thereby, combined with Dempster–Shafer theory and evidential deep learning, we propose a Pseudo-Multiview Fusion (PMvF) approach for OOD detection in fault diagnosis. PMvF aims to improve the reliability of diagnostic results by leveraging the advantages of information fusion without adding additional inputs. PMvF calculates the uncertainty in the both time and frequency domains of the single sensor and constructs fusion rules to obtain uncertainty from multiple perspectives to analyze the input. A series of experimental results validated the effectiveness of PMvF, which significantly reduced the OOD false detection rate (FPR95 decreased by 49.1%). PmvF provides a feasible novel paradigm for improving the reliability and overall performance of the model.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112661"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792359","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":"Ultrasonic coded-excitation full-matrix imaging in the wavenumber domain for coated pipe welds","authors":"Mu Chen ,&nbsp;Xinzhi Ma ,&nbsp;Zhigang Wang ,&nbsp;Xintao Xu ,&nbsp;Xu Gu ,&nbsp;Keji Yang ,&nbsp;Deqing Mei ,&nbsp;Jian Chen ,&nbsp;Haoran Jin","doi":"10.1016/j.ymssp.2025.112647","DOIUrl":"10.1016/j.ymssp.2025.112647","url":null,"abstract":"<div><div>Welds in long-distance pipelines are susceptible to defects due to stress concentration. However, the protective coating layers outside the pipe welds hinder ultrasound penetration. As a result, current ultrasonic nondestructive testing methods require removing the protective layer before detection, which is inefficient and labor-intensive. To address this challenge, a full-matrix ultrasonic imaging method is proposed, employing coded excitation and multi-mode wavenumber-domain image reconstruction. Nonlinear frequency modulation (NLFM) is combined with the Golay pair as the coded ultrasonic excitation sequences to achieve better penetration and side lobe suppression. The multi-mode wavenumber-domain image reconstruction method solves the complex wave propagation and image migration problems for welds covered with protective layers. Experimental results demonstrate that the proposed method can detect pipe weld defects in the presence of an approximately 2.6 mm three-layer polyethylene (3LPE) coating. Various common coated pipe weld defects can be detected with an average image signal-to-noise ratio of 20.8 dB. A frame rate of 4 Hz is achieved for one imaging mode.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112647"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792375","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":"Structural health monitoring of shell structures with preexisting cracks","authors":"Ihtisham Khalid ,&nbsp;Zahid Ahmed Qureshi ,&nbsp;Yasir Ali ,&nbsp;Selda Oterkus ,&nbsp;Erkan Oterkus","doi":"10.1016/j.ymssp.2025.112663","DOIUrl":"10.1016/j.ymssp.2025.112663","url":null,"abstract":"<div><div>Plate and shell-like structures are widely used in the aerospace, marine, and renewable energy sectors. However, they are susceptible to various defects, especially cracks, during their operational lifespan. Although the inverse Finite Element Method (iFEM) offers significant advantages, such as real-time shape sensing capabilities, its current formulations cannot reconstruct crack mechanics and analyze structures with preexisting cracks. Geometric discontinuities, such as cracks, present unique challenges that require special treatment in fracture mechanics. This study presents a novel inverse crack tip shell element for real-time reconstruction of full-field displacement profiles and computation of Stress Intensity Factors (SIFs), addressing the limitations of current iFEM formulations. The proposed six-node triangular inverse element is flexible in mapping complex geometries and inherently ensures strain singularity at the crack tip by repositioning its mid-side nodes. The proposed inverse formulation is numerically validated against benchmark analytical and high-fidelity Finite Element Method (FEM) reference solutions for varying geometries and crack configurations subjected to different loading and boundary conditions. The study also introduces a variational technique for optimizing sensor locations within the inverse element domain to accurately compute Stress Intensity Factors (SIFs). The proposed inverse shell formulation is computationally efficient and seamlessly integrates within the iFEM framework for real-time shape sensing and Structural Health Monitoring (SHM) of shell structures with preexisting cracks.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112663"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating remaining useful life with degraded correlated diffusion coefficient and enhanced state-space model under stable distribution process","authors":"Hongkun Li ,&nbsp;Qiang Li ,&nbsp;Zhenhui Ma ,&nbsp;Xuejun Liu ,&nbsp;Xichun Guan ,&nbsp;Xiaoli Zhang","doi":"10.1016/j.ymssp.2025.112684","DOIUrl":"10.1016/j.ymssp.2025.112684","url":null,"abstract":"<div><div>The prediction of remaining useful life (RUL) for critical component in mechanical system is crucial for optimizing operational efficiency and preventing unforeseen failure. Although traditional performance degradation models based on stochastic process have achieved significant success in RUL prediction, the fixed diffusion coefficient is commonly used, persisting unrelated to the variability in degradation increment behavior. Moreover, in the update phase of state-space model, the drift coefficient is constrained by the assumption that the current estimate should be identical to the posterior estimate from the previous time step. To address these limitations, an RUL prediction framework based on degraded correlated diffusion coefficient and enhanced state-space model is proposed. By introducing the concept of a time-varying proportional coefficient and integrating the mathematical relationship related to equipment degradation increment behavior, a degradation correlated diffusion coefficient is designed to overcome the limitation of traditional performance degradation models, which assume the diffusion coefficient is fixed. Meanwhile, the joint matrix of the drift coefficient and the time-varying proportion coefficient is embedded into the state equation of the enhanced state space model, allowing for the simultaneous adaptive updating of the drift coefficient and the time-varying proportion coefficient according to the observation equation matrix. Leveraging the evolution process of the time-varying proportion coefficient in conjunction with Monte Carlo simulation facilitates the RUL prediction of mechanical equipment and enables the quantification of associated uncertainties. The proposed RUL prediction framework is validated using full lifecycle data from on-site truck rear axle and benchmark rolling bearing datasets. The results of the cases study and comparative analysis provide validation of the effectiveness and superiority of the proposed method.</div></div>","PeriodicalId":51124,"journal":{"name":"Mechanical Systems and Signal Processing","volume":"231 ","pages":"Article 112684"},"PeriodicalIF":7.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792265","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}