Article
Engineering, Mechanical
Lucas P. Volpi, Daniel M. Lobo, Thiago G. Ritto
Summary: This paper investigates the coupled lateral-torsional vibrations of a drill string in the oil and gas industry, using deterministic and stochastic models to classify dynamic responses, analyze uncertainties, and quantify critical phenomena. New field data of drill string lateral vibrations are also presented for further analysis.
NONLINEAR DYNAMICS
(2021)
Article
Engineering, Mechanical
Xiaofeng Geng, Hu Ding, Xingjian Jing, Xiaoye Mao, Kexiang Wei, Liqun Chen
Summary: This paper proposes a new nonlinear, non-contact magnetic force to limit the large vibration of the nonlinear energy sink (NES) oscillator. The dynamic characteristics of the magnetic-enhanced NES (ME-NES) are analyzed through experiments and numerical simulations, and the impact on the oscillator is summarized. The results show that the limiting effect of nonlinear magnetic force is better than that of linear force, and the proposed non-contact ME-NES is a reliable and efficient vibration reduction strategy.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Mechanics
Pan Fang, Shujie Ding, Kang Yang, Gao Li, Dong Xiao
Summary: This paper focuses on the dynamics characteristics of the axial-torsional-lateral coupled drill string system in the air and liquid drilling process. A rotor dynamics model and two contact models are established to analyze the different vibration modes of the bottom hole assembly (BHA). The results show that the vibrations of BHA in the air drilling process are stronger than in the liquid drilling process, especially when encountering a hard formation.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2022)
Article
Engineering, Marine
Mohammadali Nasrabadi, Andrei Vladimirovich Sevbitov, Vahid Arab Maleki, Narges Akbar, Ilghar Javanshir
Summary: This study focuses on utilizing a nonlinear energy sink to control vibrations of a cantilever cylinder under external fluid flow, analyzing the effects of fluid flow velocity and nonlinear parameters on the vibration response of the system. By evaluating the impact of adding a NES on lock-in phenomena and maximum oscillating amplitudes, the study guides the determination of the optimal NES design for significant fluid-induced vibration mitigation.
Article
Mechanics
Maziar Mohammadzadeh, Mohammadreza Arbabtafti, Majid Shahgholi, Jianming Yang
Summary: This research aims to investigate the fully coupled nonlinear vibrations of composite drill strings, considering factors such as drill string-wellbore contact, bit-rock interaction, initial deformations, gyroscopic effect, and geometric stiffening effect. The study examines the capability of various configurations of composite drill strings to track and transmit the fully coupled nonlinear vibrations, as well as the effects of initial deformation and different fiber orientations and stacking sequences on reducing nonlinear vibrations in different drilling conditions.
ARCHIVE OF APPLIED MECHANICS
(2022)
Article
Engineering, Ocean
Jun Liu, Shuang Liang, Yili Chen, Min Zhang
Summary: In this study, a coupled nonlinear vibration model for riserless drill-string in deepwater, considering both seawater and stratum sections, was established. The effectiveness of the model was demonstrated qualitatively and quantitatively using torsional vibration model results and field test data. The research provides an effective analysis method and theoretical guidance for riserless drill-string design.
APPLIED OCEAN RESEARCH
(2023)
Article
Multidisciplinary Sciences
Lelya A. Khajiyeva, Igor Andrianov, Yuliya F. Sabirova, Askar K. Kudaibergenov
Summary: This study focuses on the nonlinear dynamics of drill strings using the lumped-parameter method, specifically applied to the lateral vibrations of a vertical drill string. The results confirm the accuracy and efficiency of the method, while determining the optimal number of drill-string partitions.
Article
Engineering, Ocean
Mohammad Javad Moharrami, Clovis de Arruda Martins, Hodjat Shiri
Summary: This study focused on stick-slip torsional vibration in deep-water oil and gas drilling systems, proposing an efficient FE modeling approach for the entire drill string. Research showed that self-excited torsional vibrations may occur at fundamental frequencies lower than the first natural torsional frequency of the drill string. The developed models were verified and resulted in a robust and practical integrated FE model for simulating the entire drill string system dynamics.
APPLIED OCEAN RESEARCH
(2021)
Article
Acoustics
Kamal Aghadadi, Firooz Bakhtiari-Nejad, Afshin Taghvaeipour, Ali Hosseinzadeh
Summary: This paper proposes a second order sliding mode control law for regulation of rotational speed in a non-minimum phase drill string system. The nonlinear dynamic model of a drill string in contact with non-Newtonian mud is conducted. The results show that the proposed super twisting controller is capable of adjusting the output to a desired value during sliding motion, and increasing the number of mode shapes improves computation accuracy.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Engineering, Mechanical
Zhen Zhang, Zhi-Tong Gao, Bo Fang, Ye-Wei Zhang
Summary: This study investigates the impact of geometric nonlinearity on an elastic beam and obtains the steady-state response of nonlinear vibration using the harmonic balance method. The results show that geometric nonlinearity mainly affects the first-order main resonance and reduces the response amplitude. The vibration suppression of the elastic beam is achieved by installing an inertial nonlinear energy sink.
NONLINEAR DYNAMICS
(2022)
Article
Mathematics, Applied
Adnan S. Saeed, Mohammad A. AL-Shudeifat, Wesley J. Cantwell, Alexander F. Vakakis
Summary: This study introduces a two-dimensional nonlinear energy sink (2DNES) that can robustly suppress seismic excitations in arbitrary directions on the plane. Through numerical optimization and testing with historic earthquakes, it demonstrates the effectiveness of the optimized 2D-NES in mitigating multi-directional seismic excitations.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Engineering, Mechanical
Jinxin Dou, Zhenping Li, Yanbo Cao, Hongliang Yao, Ruxue Bai
Summary: This paper investigates the application of a magnetic bi-stable nonlinear energy sink on torsional vibration suppression of the rotor system. The structure and analytical expression of the nonlinear torsional stiffness of the energy sink are introduced, and the vibration attenuation performances under different excitations are evaluated. Experimental studies are conducted to validate the results.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Engineering, Mechanical
Guilherme Rosa Franzini, Vitor Schwenck Franco Maciel, Guilherme Jorge Vernizzi, Daniele Zulli
Summary: This paper presents analytical-numerical studies on the simultaneous passive suppression of galloping and energy harvesting for a square prism. The performance of a bistable piezoelectric nonlinear energy sink (BSPNES) is compared with its monostable counterpart. The results show that the BSPNES outperforms its monostable counterpart in terms of suppression efficiency and harvested energy over a certain range of reduced velocities.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Mechanical
Xiao-Feng Geng, Hu Ding
Summary: This paper proposes an enhanced nonlinear energy sink (E-NES) design using piecewise linear springs to enhance vibration suppression effects. The design achieves better vibration suppression effects without changing the resonance frequency of the primary system. The parameters of the piecewise spring can be optimized efficiently using the differential evolution algorithm, and experiments show that the vibration elimination efficiency of the E-NES can exceed 90%.
NONLINEAR DYNAMICS
(2021)
Article
Engineering, Mechanical
Gabriel P. Araujo, Jose Augusto I. da Silva, Flavio D. Marques
Summary: The combination of a rotational NES with EH for vortex-induced vibrations of a cylinder exposed to airflow is investigated in this study. The results show that this combination has the potential to dissipate vibration energy and generate electricity simultaneously, making it suitable for the design of energy extraction devices.
JOURNAL OF FLUIDS AND STRUCTURES
(2022)
Article
Engineering, Biomedical
Alireza Mojahed, Javid Abderezaei, Efe Ozkaya, Lawrence Bergman, Alexander Vakakis, Mehmet Kurt
Summary: Sports-related traumatic brain injuries are a major cause of head injuries worldwide, and helmets play a crucial role in protecting against these injuries. However, current helmet designs often overlook the importance of regional brain deformations, particularly near deep white matter structures like the corpus callosum. This study develops a dynamic model of the skull-brain-helmet system to investigate the impact of various helmet parameters on head and corpus callosum dynamics. The findings show that the optimal helmet coupling values differ for minimizing corpus callosum dynamics compared to skull and brain dynamics, indicating the need to consider tissue-level dynamics in helmet design.
ANNALS OF BIOMEDICAL ENGINEERING
(2022)
Article
Acoustics
Timo Theurich, Alexander F. Vakakis, Malte Krack
Summary: This study investigates the optimal design of impact absorbers for flexible host structures, analyzing the impact dynamics at short and long time scales to conclude that the design problem can be simplified to four dimensionless parameters.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Alexander F. Vakakis, Oleg Gendelman, Lawrence A. Bergman, Alireza Mojahed, Majdi Gzal
Summary: This paper provides a brief overview of the current progress in the field of nonlinear targeted energy transfer (TET) and discusses some future directions for research. The authors introduce four emerging research areas, including intermodal targeted energy transfer, implementation of TET in nonlinear acoustic metamaterials, the breakdown of classical reciprocity in elastodynamics in the context of TET, and the impact of TET on the bandwidth of general classes of nonlinear resonators. The aim of the authors is to outline the main ideas, summarize recent developments, suggest possible directions for future work, and encourage further research in both the discussed topics and other TET-related areas.
NONLINEAR DYNAMICS
(2022)
Article
Mechanics
Jian En Chen, Timo Theurich, Malte Krack, Themistoklis Sapsis, Lawrence A. Bergman, Alexander F. Vakakis
Summary: The dynamics of linear oscillators attached to hierarchical chains of strongly nonlinear oscillators are studied in this research. It is found that at low excitation levels, the system exhibits linear behavior, while at high excitation levels, the system enters a chaotic state with energy cascading across the nonlinear chain. Additionally, chaotic synchronization is observed.
Article
Engineering, Multidisciplinary
Xiangle Cheng, D. Michael McFarland, Huancai Lu, Alexander F. Vakakis, Lawrence A. Bergman
Summary: An analytical approach is presented for localizing travelling and standing waves on a circular membrane using an interior, continuous, ring-type viscoelastic support. The results are expected to be useful in the design of mechanical and acoustic systems for energy localization.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Acoustics
Alireza Mojahed, Lawrence A. Bergman, Alexander F. Vakakis
Summary: This paper focuses on formulating the concept of bandwidth for a general class of passive oscillatory dynamical systems and proposes a new bandwidth definition based on the transient energy evolution. The new definition overcomes the limitations of previous definitions and is compatible with nonlinear dynamics. It allows for quantifying and studying the contributions of individual harmonics and targeted energy transfers to the bandwidth.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Acoustics
C. Wang, A. Mojahed, S. Tawfick, A. Vakakis
Summary: This work explores the acoustics of an infinite, one-dimensional, linear waveguide with a nonlinear gate, utilizing neural network simulators to study the nonlinear acoustics and global non-reciprocity of the waveguide. By training the neural networks with simulation data and comparing the results, predictive design of the waveguide's acoustic non-reciprocity response regions can be achieved effectively.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Mohammad A. Bukhari, Oumar R. Barry, Alexander F. Vakakis
Summary: This work investigates the nonlinear acoustics of a 1D discrete strongly nonlinear locally resonant metamaterial. Numerical investigations demonstrate the existence of different families of traveling breathers that depend on the coupling coefficient. The outcome indicates the presence of two energy-dependent nonlinear propagation zones and three complementary attenuation zones for the infinite lattice case.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Mathematics, Applied
Chongan Wang, Alexander F. Vakakis, Sameh Tawfick
Summary: In this study, non-reciprocal frequency conversion is investigated in a linear two-dimensional acoustic waveguide with a nonlinearly coupled oscillator gate. The efficacy and robustness of frequency conversion are validated through numerical simulations, and it is found that the frequency conversion induced by the nonlinear gate is sensitive to the excitation parameters and exhibits non-reciprocity in energy transfer.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Engineering, Civil
Majdi Gzal, Juan E. Carrion, Mohammad A. AL-Shudeifat, Billie F. Spencer, Joel P. Conte, Alexander F. Vakakis, Lawrence A. Bergman, Oleg Gendelman
Summary: This study investigates a new intermodal targeted energy transfer (IMTET) concept for rapid and purely passive seismic mitigation of a twenty-story steel structure. The concept is based on introducing local strong vibro-impact nonlinearities generated by contacts between floors and an auxiliary core structure to scatter seismic input energy. The results show that IMTET can effectively redistribute energy and enhance seismic performance without adding mass to the building.
ENGINEERING STRUCTURES
(2023)
Article
Acoustics
Ali Kanj, Alexander F. Vakakis, Sameh Tawfick
Summary: On-chip phononic circuits enable customized transmission of elastic waves and can couple with electronics and photonics for new signal manipulation capabilities. A reduced-order model is constructed to demonstrate the transmission switching mechanism in coupled drumhead-resonator waveguides, showing how thermoelastic buckling induces phase transition and localization of frequency passband modes.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Engineering, Mechanical
Ali Kanj, Paolo Ferrari, Arend M. van der Zande, Alexander F. Vakakis, Sameh Tawfick
Summary: Nonlinear micro-electro-mechanical systems (MEMS) resonators offer new opportunities in sensing and signal manipulation through frequency tuning and increased bandwidth. This study designs, fabricates, and investigates drumhead resonators with strongly nonlinear dynamics, developing a reduced order model (ROM) to accurately capture their response. The resonators exhibit electrostatically-mediated thermoelastic buckling, with a tunability factor of 2.4x and switching between stiffness and softness.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Physics, Fluids & Plasmas
Joshua R. Tempelman, Alexander F. Vakakis, Kathryn H. Matlack
Summary: This paper proposes a method for manipulating wave propagation in phononic lattices by utilizing local vibroimpact nonlinearities. It demonstrates the scattering of energy in the wave number domain and the transfer of energy from lower to higher optical bands. The study also explores the concept of nonresonant interband targeted energy transfer and establishes scaling relations with respect to energy. The nonlinear dynamics of the system and the physical interpretation of the energy transfer are analyzed using numerical continuation and nonlinear normal modes.
Article
Acoustics
Joshua R. Tempelman, Alexander F. Vakakis, Kathryn H. Matlack
Summary: In this work, the researchers demonstrate the interpretation of propagating topological waves in valley Hall lattices using the linear degenerate modal basis. They show that a small subset of closely spaced modes make up the topological waves, allowing for the construction of analytical reduced-order models. This is possible due to the sparse density of the modal spectrum inside the topological band gap. The researchers utilize this result to refine group velocity predictions of propagating topological waves by matching the modal spectrum to the supercell dispersion diagram. They also use the damped modal spectrum to characterize variations in wave group velocity in damped topological lattices and predict edge-to-bulk transitions. This work establishes a framework for accurately characterizing undamped and damped topological wave propagation using classical dynamics.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Engineering, Mechanical
Xiang Li, Alireza Mojahed, Li-Qun Chen, Lawrence A. Bergman, Alexander F. Vakakis
Summary: A lightweight geometrically nonlinear attachment is used to suppress the shock response of a linear, large-scale nine-story structure, achieving nonlinear targeted energy transfer from low to high frequencies.
ACTA MECHANICA SINICA
(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)
