Article
Engineering, Mechanical
Qiang Wang, Jiaxi Zhou, Kai Wang, Qida Lin, Daolin Xu, Guilin Wen
Summary: In this study, a novel compact energy harvesting dynamic vibration absorber with quasi-zero-stiffness characteristics is developed for vibration suppression and energy harvesting under low frequency. The analytical expressions of the force and stiffness of the negative stiffness magnetic spring are derived, and the restoring force of the spiral flexure spring is analyzed. By solving the electromechanically coupled equations using the Harmonic Balance Method, the impact of system parameters on vibration suppression and energy harvesting is investigated. The experimental results demonstrate that the proposed device can effectively suppress vibration and generate power in the low frequency range.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Gianluca Gatti, Diego F. Ledezma-Ramirez, Michael J. Brennan
Summary: A novel nonlinear isolator is proposed in this paper, which outperforms the classical quasi-zero stiffness nonlinear isolator when subjected to large inputs. The response of the isolator to shock excitation is investigated, and a suspension system with a quasi-static force-deflection curve of sigmoidal shape is designed. Simulations show that the proposed four-spring system achieves higher maximum displacement of a suspended mass compared to the classical three-spring nonlinear configuration when the shock amplitude is relatively large.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
G. Gatti, A. D. Shaw, P. J. P. Goncalves, M. J. Brennan
Summary: A translational Lanchester damper adds damping to a structure using a combination of viscous damper and mass, but achieving low stiffness for the device is crucial to behave like a Lanchester damper rather than a dynamic vibration absorber. By utilizing a specific geometry with linear springs and rigid links, the device is able to maintain linear-like behavior despite its inherent nonlinearity. The study on how geometry affects the nonlinear behavior provides general guidelines for design, and a prototype incorporating the low stiffness element has been successfully tested on vibrating structures.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Engineering, Mechanical
Zhao-Yang Xing, Xiao-Dong Yang
Summary: The vibration control performance of a combined vibration isolation system is investigated, which consists of a quasi-zero stiffness system and a linear dynamic vibration absorber. The dynamic equation is established and the amplitude-frequency response of the system is deduced and verified. The mechanism and tuning rule for the system are revealed, and the control performance is analyzed in terms of various factors. The results show that the system effectively suppresses vibration amplitude and broadens the isolation frequency band, providing valuable reference for improving control performance.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Acoustics
Yaopeng Chang, Jiaxi Zhou, Kai Wang, Daolin Xu
Summary: This paper proposes a quasi-zero-stiffness (QZS) DVA for ultra-low frequency vibration absorption, which is designed using a simple oblique-spring model and verified for its dynamic behavior through the harmonic balance method (HBM) and numerical analyses. Experimental results demonstrate the excellent performance of QZS DVA in absorbing ultra-low frequency vibrations.
JOURNAL OF SOUND AND VIBRATION
(2021)
Review
Engineering, Electrical & Electronic
Zhaozhao Ma, Ruiping Zhou, Qingchao Yang
Summary: This paper comprehensively reviews recent research on quasi-zero stiffness (QZS) vibration isolators, focusing on their principle, structural design, and vibration isolation performance. The paper also summarizes the development trends and challenges of QZS vibration isolators, as well as the advantages of passive and active/semi-active systems.
Article
Engineering, Mechanical
Junhan An, Guoping Chen, Xi Deng, Chen Xi, Tao Wang, Huan He
Summary: This paper examines the dynamic phenomenon of a pneumatic QZS isolator with mistuned mass and analyzes the amplitude-frequency relationship and force transmissibility. The results show that, in the case of a large mass mistuning, the system exhibits possible response periods and chaos phenomena. Mass detuning leads to a more complex nonlinear response of the QZS isolator, and the dynamic response becomes more sensitive to changes in parameters such as external excitation frequency, amplitude, and damping ratio. These findings are helpful for improving the structure of the pneumatic QZS vibration isolator and determining the applicable working frequency.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Chen Zhang, Junsen He, Guiqian Zhou, Kai Wang, Daolin Xu, Jiaxi Zhou
Summary: The study proposes a compliant quasi-zero-stiffness (CQZS) isolator to isolate low-frequency torsional vibrations in the shaft system. The configuration of the CQZS isolator is devised using a compliant mechanism, and its stiffness characteristics are deduced and verified analytically and numerically. A dynamic model of the shaft system integrated with the CQZS isolator is established, and theoretical analysis is conducted using the harmonic balance method. Experimental results confirm the effectiveness of the CQZS isolator in achieving ideal torsional quasi-zero-stiffness characteristics and low-frequency torsional vibration isolation. The proposed CQZS isolator is more compact, lightweight, and easier to manufacture than conventional isolators.
MECHANISM AND MACHINE THEORY
(2023)
Article
Engineering, Mechanical
Chun Cheng, Yan Hu, Ran Ma, Weiping Wang
Summary: A displacement-velocity feedback control method is proposed to improve the isolation performance of a quasi-zero-stiffness vibration isolator (QZS-VI). The study considers the effect of time delay and analyzes its impact on system stability and frequency response. The results show that the proposed control method can effectively suppress vibration in the resonant region without affecting the performance in the isolation region.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Mechanical
Kan Ye, J. C. Ji
Summary: In this study, an origami-inspired vibration isolator with quasi-zero-stiffness (QZS) property is proposed using a truss-spring based stack Miura-ori (TS-SMO) structure. The unique structure uses coil spring sets to replace deformable creases, improving physical realization in engineering applications. Nonlinear force response and QZS feature are achieved through geometric nonlinearity and specific Poisson's ratio profile, with isolation performance discussed under variable viscous damping effects.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Acoustics
Gianluca Gatti, Cesare Svelto
Summary: This paper presents a theoretical insight on the performance of a vibration isolator with a specific form of geometric nonlinearity. The analytical findings are validated by numerical simulations, providing useful guidelines for the design of such isolators.
JOURNAL OF VIBRATION AND CONTROL
(2022)
Article
Engineering, Mechanical
Yang Zhang, Xi Wang, Qianzheng Du, Tao Wang, Guoqiang Fu, Caijiang Lu
Summary: The purpose of this paper is to propose an energy harvester with quasi-zero stiffness, capable of generating electricity effectively through large amplitude vibration at low frequency, and having a simple structure, light weight, and high working efficiency. The proposed energy harvester adopts a levitating magnet composed of a multi-magnet array, which experiences little resultant force in a larger motion range, exhibiting quasi-zero stiffness characteristics. In the experiment, the LED array is successfully lit, and the maximum output power of the system can reach 1 mW under specific excitation conditions, demonstrating the high working efficiency of the energy harvester.
JOURNAL OF VIBRATION ENGINEERING & TECHNOLOGIES
(2023)
Article
Engineering, Multidisciplinary
Qiang Wang, Jiaxi Zhou, Kai Wang, Jinghang Gao, Qida Lin, Yaopeng Chang, Daolin Xu, Guilin Wen
Summary: This paper proposes a dual-function quasi-zero-stiffness energy harvesting dynamic vibration absorber (EHDVA) to simultaneously mitigate vibration and harvest energy. The device consists of a quasi-zero-stiffness absorber and an electromagnetic transducer, which can achieve high-efficiency vibration attenuation and energy harvesting at ultra-low frequency.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Engineering, Mechanical
Zhaozhao Ma, Ruiping Zhou, Qingchao Yang, Heow Pueh Lee, Kai Chai
Summary: A semi-active electromagnetic quasi-zero-stiffness (QZS) vibration isolator (VI) has been proposed to expand the frequency bandwidth for low or ultra-low frequency vibration isolation. The innovative electromagnetic negative stiffness mechanism (NSM) utilizes an 8-shaped electromagnetic equivalent magnetic circuit, providing a wider tunable range of negative stiffness compared to previous studies. Theoretical formulations for the SEQZS VI, including static and dynamic analyses under harmonic excitations, have been derived and parameter analysis has been conducted for design reference. Experimental results from a prototype verify the effectiveness of the SEQZS VI, which outperforms linear isolators in terms of vibration isolation performance and exhibits lower stiffness and transmissibility at the resonance frequency.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Mechanical
Yaopeng Chang, Jiaxi Zhou, Kai Wang, Daolin Xu
Summary: The semi-active quasi-zero-stiffness dynamic vibration absorber (SAQZS DVA) with an electromagnetic actively regulatory mechanism (ARM) embedded in it allows for vibration absorption tuning in ultra-low frequencies, showing effective vibration absorption and tuning capabilities. Experimental results indicate that the SAQZS DVA can achieve vibration absorption at ultra-low frequencies.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Xuanen Kan, Yanjun Lu, Fan Zhang, Weipeng Hu
Summary: A blade disk system is crucial for the energy conversion efficiency of turbomachinery, but differences between blades can result in localized vibration. This study develops an approximate symplectic method to simulate vibration localization in a mistuned bladed disk system and reveals the influences of initial positive pressure, contact angle, and surface roughness on the strength of vibration localization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zimeng Liu, Cheng Chang, Haodong Hu, Hui Ma, Kaigang Yuan, Xin Li, Xiaojian Zhao, Zhike Peng
Summary: Considering the calculation efficiency and accuracy of meshing characteristics of gear pair with tooth root crack fault, a parametric model of cracked spur gear is established by simplifying the crack propagation path. The LTCA method is used to calculate the time-varying meshing stiffness and transmission error, and the results are verified by finite element method. The study also proposes a crack area share index to measure the degree of crack fault and determines the application range of simplified crack propagation path.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Rongjian Sun, Conggan Ma, Nic Zhang, Chuyo Kaku, Yu Zhang, Qirui Hou
Summary: This paper proposes a novel forward calculation method (FCM) for calculating anisotropic material parameters (AMPs) of the motor stator assembly, considering structural discontinuities and composite material properties. The method is based on multi-scale theory and decouples the multi-scale equations to describe the equivalence and equivalence preconditions of AMPs of two scale models. The effectiveness of this method is verified by modal experiments.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Zhang, Jiangcen Ke
Summary: This research introduces an intelligent scheduling system framework to optimize the ship lock schedule of the Three Gorges Hub. By analyzing navigational rules, operational characteristics, and existing problems, a mixed-integer nonlinear programming model is formulated with multiple objectives and constraints, and a hybrid intelligent algorithm is constructed for optimization.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Jingjing He, Xizhong Wu, Xuefei Guan
Summary: A sensitivity and reliability enhanced ultrasonic method has been developed in this study to monitor and predict stress loss in pre-stressed multi-layer structures. The method leverages the potential breathing effect of porous cushion materials in the structures to increase the sensitivity of the signal feature to stress loss. Experimental investigations show that the proposed method offers improved accuracy, reliability, and sensitivity to stress change.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Benyamin Hosseiny, Jalal Amini, Hossein Aghababaei
Summary: This paper presents a method for monitoring sub-second or sub-minute displacements using GBSAR signals, which employs spectral estimation to achieve multi-dimensional target detection. It improves the processing of MIMO radar data and enables high-resolution fast displacement monitoring from GBSAR signals.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xianze Li, Hao Su, Ling Xiang, Qingtao Yao, Aijun Hu
Summary: This paper proposes a novel method for bearing fault identification, which can accurately identify faults with few samples under complex working conditions. The method is based on a Transformer meta-learning model, and the final result is determined by the weighted voting of multiple models.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaomeng Li, Yi Wang, Guangyao Zhang, Baoping Tang, Yi Qin
Summary: Inspired by chaos fractal theory and slowly varying damage dynamics theory, this paper proposes a new health monitoring indicator for vibration signals of rotating machinery, which can effectively monitor the mechanical condition under both cyclo-stationary and variable operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Hao Wang, Songye Zhu
Summary: This paper extends the latching mechanism to vibration control to improve energy dissipation efficiency. An innovative semi-active latched mass damper (LMD) is proposed, and different latching control strategies are tested and evaluated. The latching control can optimize the phase lag between control force and structural response, and provide an innovative solution to improve damper effectiveness and develop adaptive semi-active dampers.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Menghao Ping, Xinyu Jia, Costas Papadimitriou, Xu Han, Chao Jiang, Wang-Ji Yan
Summary: Identification of non-Gaussian processes is a challenging task in engineering problems. This article presents an improved orthogonal series expansion method to convert the identification of non-Gaussian processes into a finite number of non-Gaussian coefficients. The uncertainty of these coefficients is quantified using polynomial chaos expansion. The proposed method is applicable to both stationary and nonstationary non-Gaussian processes and has been validated through simulated data and real-world applications.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Lei Li, Wei Yang, Dongfa Li, Jianxin Han, Wenming Zhang
Summary: The frequency locking phenomenon induced by modal coupling can effectively overcome the dependence of peak frequency on driving strength in nonlinear resonant systems and improve the stability of peak frequency. This study proposes the double frequencies locking phenomenon in a three degrees of freedom (3-DOF) magnetic coupled resonant system driven by piezoelectricity. Experimental and theoretical investigations confirm the occurrence of first frequency locking and the subsequent switching to second frequency locking with the increase of driving force. Furthermore, a mass sensing scheme for double analytes is proposed based on the double frequencies locking phenomenon.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Kai Ma, Jingtao Du, Yang Liu, Ximing Chen
Summary: This study explores the feasibility of using nonlinear energy sinks (NES) as replacements for traditional linear tuned mass dampers (TMD) in practical engineering applications, specifically in diesel engine crankshafts. The results show that NES provides better vibration attenuation for the crankshaft compared to TMD under different operating conditions.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Wentao Xu, Li Cheng, Shuaihao Lei, Lei Yu, Weixuan Jiao
Summary: In this study, a high-precision hydraulic mechanical stand and a vertical mixed-flow pumping station device were used to conduct research on cavitation signals of mixed-flow pumps. By analyzing the water pressure pulsation signal, it was found that the power spectrum density method is more sensitive and capable of extracting characteristics compared to traditional time-frequency domain analysis. This has significant implications for the identification and prevention of cavitation in mixed-flow pump machinery.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Xiaodong Chen, Kang Tai, Huifeng Tan, Zhimin Xie
Summary: This paper addresses the issue of parasitic motion in microgripper jaws and its impact on clamping accuracy, and proposes a symmetrically stressed parallelogram mechanism as a solution. Through mechanical modeling and experimental validation, the effectiveness of this method is demonstrated.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)
Article
Engineering, Mechanical
Zhifeng Shi, Gang Zhang, Jing Liu, Xinbin Li, Yajun Xu, Changfeng Yan
Summary: This study provides useful guidance for early bearing fault detection and diagnosis by investigating the effects of crack inclination and propagation direction on the vibration characteristics of bearings.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2024)