Article
Materials Science, Multidisciplinary
Ding Jia, Yong Ge, Haoran Xue, Shou-qi Yuan, Hong-xiang Sun, Yihao Yang, Xiao-jun Liu, Baile Zhang
Summary: Researchers experimentally demonstrated dual-band valley sonic crystals, where robust valley kink states exist in two separated bulk band gaps, and the two opposite valleys in these two band gaps are locked to a single propagation direction.
Article
Physics, Multidisciplinary
Li Yin-Ming, Kong Peng, Bi Ren-Gui, He Zhao-Jian, Deng Ke
Summary: The study focuses on the topological properties of a double surface periodic phononic crystal based on elastic material. By numerical simulation, the researchers observe the existence of valley topological states and analyze the theoretical valley Chern number. The study demonstrates the possibility of energy band inversion and topological phase transition by adjusting the geometry of the scatterer. The researchers also find that controlling the edge state frequency in the valley topology is achievable by adjusting the heights of the scatterers.
ACTA PHYSICA SINICA
(2022)
Article
Physics, Condensed Matter
Long-chao Yao, Kuan-Hong Hsieh, Shih-Chia Chiu, Hong-kang Li, Shao-yong Huo, Chun-ming Fu
Summary: By constructing structures with different topological phases, the transmission path of elastic waves can be controlled selectively based on frequency.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Materials Science, Multidisciplinary
Chun-Ming Fu, Long-Chao Yao, Shao-Yong Huo, Hong-Kang Li
Summary: This paper designs a 2D solid topological phononic crystal (PnC) with adjustable valley edge states and rainbow trapping effects. By introducing defects and breaking spatial inversion symmetry, the valley Hall phase transition and edge states of elastic waves are achieved. The defect-adjusted valley edge states are further used to design novel elastic ultrasonic devices. This research provides important guidance for the development of ultrasonic devices.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Chengxin Cai, Guangchen He, Zhoufu Zheng, Yao Qin, Jianfei Yin
Summary: In this study, the edge states of a designed elastic phononic crystal plate were modulated to achieve greater degrees of freedom and enhanced backscattering suppression capabilities. Straight boundary, right-angle turning boundary, and valley topological transport with defect and disordered boundary were achieved by utilizing edge states. Experimental validation confirmed the robustness against immunodeficiency and holes. The relative width of the topological band gap in the elastic wave system examined in this study exceeds 60%, offering significant advantages and potential for practical applications. This research contributes new insights for engineering applications of ultra-wideband acoustic antennas, acoustic logic control, and other devices.
RESULTS IN PHYSICS
(2023)
Article
Engineering, Mechanical
Shuowei An, Tuo Liu, Haiyan Fan, He Gao, Zhongming Gu, Shanjun Liang, Sibo Huang, Yi Zheng, Yafeng Chen, Li Cheng, Jie Zhu
Summary: This study proposes a second-order elastic topological insulator (SETI) with valley-selective topological corner states, which can be activated by engineering the valley positions. Experimental results validate the existence of valley-selective corner states and the anti-symmetric displacement profile. This research provides a new approach for the flexible manipulation of elastic waves and has potential applications in various fields.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Physics, Applied
Jiangle He, Shiyin Jia, Yaxuan Li, Junzheng Hu, Renwen Huang, Guangxu Su, Minghui Lu, Peng Zhan, Fanxin Liu
Summary: In this work, we propose a theoretical scheme for achieving topologically switchable and valley-selective corner states based on two-dimensional C-3-symmetric photonic crystals. By concatenating two valley photonic crystals with contrasting topological indices, we demonstrate the emergence of two types of valley-locked chiral topological edge states resulting from valley-valley interaction. The system exhibits two distinct types of highly robust and localized corner states when the photonic crystals are spliced at a 60 degrees angle, but the corner states are absent when the splicing angle is set as 120 degrees.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Mechanical
Guanliang Yu, Weihao Wang, Liyan Lai, Tongrui Peng, Chun Jiang, Yigui Li
Summary: Tunable topological insulators with active tunability of frequency or path have attracted significant interest recently. This study focuses on tunable spatial paths in addition to frequency domain research. The researchers have developed a topological protection system using a thermally tunable elastic film composed of VO2 on a patterned substrate. By breaking the symmetry of the unit cell on the substrate and pre-defining topological protection paths, they achieve conduction or blocking of elastic waves using VO2's metal-insulator phase transition, enabling reconfigurable propagation paths and interfaces. Numerical simulations demonstrate the reconfigurable topological path and thermal modulation potential.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Physics, Applied
Shao-Yong Huo, Hong-Kang Li, Cong-Ying Chen, Jian Deng, Long-Chao Yao, Chun-Ming Fu, Hong-Bo Huang, Wei Qu
Summary: In this study, a dual-band valley topological refraction material for elastic waves is demonstrated, and the robustness of valley edge states is investigated. The topological refractions of valley edge states from the interface into the free space are explored. This research holds significance for potential applications in multi-band and multi-directional devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Physics, Applied
Jiajun Ma, Chunmei Ouyang, Yuting Yang, Hongyi Li, Li Niu, Xinyue Qian, Yi Liu, Bin Yang, Quan Xu, Yanfeng Li, Liyuan Liu, Zhen Tian, Jianqiang Gu, Jiaguang Han, Weili Zhang
Summary: Topological photonics has advanced from theoretical concept to practical applications, with valley topological photonic crystals being a key candidate for future functional devices. However, the design and arrangement limitations have hindered the exploration of multichannel valley topological beam splitters. In this study, we investigate and demonstrate the robustness of different domain walls in valley topological photonic crystals and present a highly integrated multichannel valley topological beam splitter. Compared to traditional beam splitters, it is more robust, compact, and offers higher integration and more output ports. This brings new opportunities for engineering the flow of light and designing miniaturized integrated photonic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Jinfeng Zhao, Chenwen Yang, Weitao Yuan, Danmei Zhang, Yang Long, Yongdong Pan, Hong Chen, Zheng Zhong, Jie Ren
Summary: This study reports the observation of local elastic valley spin and the previously overlooked hidden elastic spin-valley locking mechanism. By controlling the elastic spin, the direction of valley phonon state transmission along the interface can be reversed. This discovery offers a new tool for exploring topological metamaterials.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Fabian R. Geisenhof, Felix Winterer, Anna M. Seiler, Jakob Lenz, Ivar Martin, R. Thomas Weitz
Summary: In electrostatically-gapped bilayer graphene, topologically protected states can emerge at stacking domain walls even without a magnetic field. This study focuses on the interplay between these domain wall states and quantum Hall edge transport, finding that low magnetic fields maintain a constant conductance while high magnetic fields exhibit transport suppression.
NATURE COMMUNICATIONS
(2022)
Article
Mechanics
Junrui Jiao, Tinggui Chen, Dejie Yu
Summary: In this study, the researchers achieved the transport of elastic waves in wide straight and bent waveguides by constructing a sandwich-like structure. The splitting and converging effects of elastic waves were also realized based on the valley-locking property. This research may contribute to the design of innovative devices for energy harvesting, sensing, and information processing.
COMPOSITE STRUCTURES
(2022)
Article
Physics, Applied
Anchen Ni, Zhifei Shi
Summary: In this work, a novel inertial amplified topological metamaterial beam is proposed to overcome the large mass limitation for low-frequency topologically protected interface modes. The dynamic characteristics of the system are investigated through detailed analytical and numerical studies. The existence of the topologically protected interface modes is verified through transmission simulation. The lower-frequency Dirac cone and wider local resonance bandgaps are obtained without sacrificing total stiffness or increasing total mass.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Crystallography
Zehuan Tang, Jiachao Xu, Bowei Wu, Shuanghuizhi Li, Fei Sun, Tingfeng Ma, Iren Kuznetsova, Ilya Nedospasov, Boyue Su, Pengfei Kang
Summary: This paper explores the topological transports of elastic waves in periodic triangular-lattice structures. It is found that differences between intra-coupling and inter-coupling radii can lead to the destruction of the effective spatial inversion symmetry, resulting in the valley Hall phase transition and the formation of topological edge states. By utilizing the valley Hall effect, topological transports of elastic waves along linear and Z-shaped waveguides are achieved with low scattering and immunity to defects. The path-selection function of elastic wave transports in periodic triangular-lattice structures is obtained. The topological valley Hall edge states in these structures have promising applications in elastic-wave manipulations and communications.
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)