Article
Mechanics
Yanqi Liu, Wen Ji, Erjie Deng, Xin Wang, Chunfang Song
Summary: This study presents a two degree-of-freedom quasi-zero stiffness (QZS) vibration isolator based on the anti-resonance characteristics of a multi-degree-of-freedom system. Nonlinear inclined springs (NIS) are used to achieve the nonlinear stiffness, with both linear and cubic stiffness terms. The effects of various mechanical and structural parameters on the stiffness characteristics are analyzed, and the dynamic response and force transmissibility are numerically discussed. The results show that the system can achieve smaller stiffness and wider low-stiffness range near equilibrium position by using smaller structural parameters and nonlinear inclined springs with softening stiffness.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Acoustics
Mei-Qi Wang, En-Li Chen, Peng-Fei Liu, Zhuang Qi, Jun Wang, Yu-Jian Chang
Summary: A piecewise hysteresis nonlinear dynamic model is established and the influence of different piecewise nonlinear factors on system stability is explored. The bifurcation behavior of the system under different external disturbances is analyzed, revealing various complex dynamic behaviors. Lower buffer damping leads to the chaotic state of the system's dynamic behavior.
JOURNAL OF LOW FREQUENCY NOISE VIBRATION AND ACTIVE CONTROL
(2021)
Article
Materials Science, Multidisciplinary
Katari Kiran, Umanath R. Poojary, K. Gangadharan
Summary: In this study, a modeling approach is presented to estimate the parameters of the MRE isolator model by analyzing the transmissibility response. Both fractional Kelvin Voigt and fractional Zener modeling approaches are found to effectively portray the transmissibility response, with the fractional Zener model being more accurate. The proposed models can reproduce the experimentally determined magnitude and phase response with high accuracy.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2022)
Article
Engineering, Civil
Piao Sheng, Shuangxi Jing, Zhenhua Zhang
Summary: This research investigates the effects of the stiffness of springs and rods in a QZS isolator on its mechanical characteristics and isolation performance. The optimal stiffness ratio of horizontal spring to vertical spring is slightly greater than 0.5 for a reasonable compromise between peak amplitude control and peak force transmissibility reduction. Additionally, when the stiffness ratio of the oblique rod to the vertical spring is greater than 2, the QZS isolator with finite-stiffness oblique rods has similar isolation performance as that of the existing QZS isolator with rigid oblique rods.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2022)
Article
Engineering, Mechanical
Shihua Zhou, Bowen Hou, Lisheng Zheng, Pingzhen Xu, Tianzhuang Yu, Zhaohui Ren
Summary: A novel bio-inspired vibration isolation-absorption (BIVIA) system is presented, inspired by the anti-vibration and shock absorption properties of the ostrich. The system is designed to achieve wideband vibration isolation bandwidth, low-frequency/ultra-low-frequency vibration isolation, and high stability using a toe-leg-spine coupling structure. The influences of different parameters on the performance of the BIVIA system are discussed, and it is found that coupled vibration isolation-absorption structures can achieve high loading capacity and extended quasi-zero stiffness (QZS) zone. The adjustable vibration isolation-absorption performance of the BIVIA structure makes it a practical method for bio-inspired vibration isolation, suitable for engineering and manufacturing applications.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Mechanical
Noriaki Yamamoto, Tomoya Tsuji, Michio Murase, Koji Urakabe, Takuya Yoshimura
Summary: The study successfully visualized the contents of FRFs by decomposing them into geometric paths using a signal flow graph, and quantitatively evaluated the contributions of the paths to the FRFs. This analytical methodology can help identify the cause behind loud and unpleasant noise or vibration in industrial products, and provide a basis for taking quantitative countermeasures based on analytical results.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Optics
Yanqi Zhang, Felipe Guzman
Summary: In this paper, a fiber-based two-wavelength heterodyne interferometer is proposed as a compact and highly sensitive displacement sensor. The effects of periodic errors due to imperfect spectral separation on displacement measurement are investigated, and algorithms to mitigate these effects are proposed.
Article
Acoustics
Xiaoyun Zhang, Dengqing Cao, Mei Liu, Yishen Tian, Jie Tang, Bolong Jiang, Wenhu Huang
Summary: This paper proposes a negative stiffness device composed of two horizontal pre-compression springs to isolate the vibration of a simply supported beam. The effects of support position and negative stiffness parameters on the natural frequency of the beam are analyzed, and the influence of the negative stiffness support parameters on the amplitude-frequency curve and transmissibility curve of the simply supported beam is discussed.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Engineering, Mechanical
Zhuang Dong, Baiyang Shi, Jian Yang, Tianyun Li
Summary: The study introduces a nonlinear passive joint device based on inerter for vibration attenuation in coupled systems. The proposed joint can effectively shift response peaks to lower frequencies, substantially reducing vibrations and energy transmission between subsystems when added to the force-excited subsystem or to the coupling interface of subsystems.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Baiyang Shi, Wei Dai, Jian Yang
Summary: This study presents a nonlinear vibration isolator with a geometrical nonlinearity created by configuring an inerter in a diamond-shaped linkage mechanism. The use of the nonlinear inerter in the isolator shifts and bends the peaks of the transmissibility and power flow to the low-frequency range, creating a larger frequency band of effective vibration isolation.
NONLINEAR DYNAMICS
(2022)
Article
Engineering, Mechanical
Yiming Cao, Weijiao Chen, Hui Ma, Hui Li, Bing Wang, Li Tan, Xin Wang, Qingkai Han
Summary: In this study, a novel nonlinear clamp model with four degrees of freedom is proposed for the metal rubber clamp in pipeline system. The model is verified and its effectiveness is demonstrated through modal tests and vibration response experiments. Different clamp types are also tested to evaluate their supporting performance. The numerical results are consistent with the experimental data, showing that the proposed model effectively captures the nonlinear effects of the pipeline system and enables more accurate prediction of vibration responses.
NONLINEAR DYNAMICS
(2023)
Article
Mechanics
Xiaohan Zhang, Qingjie Cao, Wenhu Huang
Summary: This paper analyzes the dynamic characteristics of a quasi-zero-stiffness isolator under mechanical disturbance, considering parameters such as nonlinear damping, friction, and inertia of rods. It suggests introducing nonlinear damping to reduce the peak value of transmissibility and limiting the mass of the rod appropriately. These conclusions provide engineering guidance for the design and application of quasi-zero-stiffness systems.
ARCHIVE OF APPLIED MECHANICS
(2021)
Article
Mechanics
Prashik Malhari Ramteke, Subrata Kumar Panda, Brijesh Patel
Summary: This study examines the eigenfrequency characteristics of the doubly-curved FG panel with multi-directional grading influence and geometrical large deformation. A mathematical model is established using HSDT mid-plane kinematics and Green Lagrange nonlinear strain terms, with finite element technique for discretization and Hamilton's principle for governing equation. A MATLAB computer code is developed for calculating nonlinear frequencies, validated and tested for convergence, showcasing the influence of various design parameters on nonlinear eigenfrequency parameters.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Mechanical
Jie Kang, Hehua Ju, Li Liu
Summary: Transmissibility-based operational modal analysis methods have rapidly developed over the last two decades, allowing for extraction of modal parameters from various load cases. Despite their ability to identify modal parameters under non-white excitations, challenges such as robustness under different load conditions and noise influence still exist. The methods are shown to be independent of input spectra under certain conditions, with user-defined parameters playing crucial roles in their identification ability.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Mechanics
Shihua Zhou, Pingzhen Xu, Bowen Hou, Zhaohui Ren
Summary: In this research, a bilayer bio-inspired X-shaped vibration isolation structure (BBXVI) considering the coordination between skeleton and muscle/tendon is proposed based on the vibration isolation properties of the biped bird. The statics analysis is conducted to analyze the mapping relationships of equivalent restoring force-displacement and equivalent stiffness-displacement. The effects of various parameters on the dynamic characteristics and vibration transmissibility of the BBXVI are studied using the incremental harmonic balance method (IHBM).
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
