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Effects and mechanisms of the main longitudinal beam shape on vortex-induced vibrations of Π-shaped composite girders

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structures 2025年 78卷

作者： Kaiwen Li Yifei Sun Qingkuan Liu Yangxue Wang Qingcai Wang Binxuan Wang School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang 050043 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang 050043 China Key Laboratory of Roads and Railway Engineering Safety Control Ministry of Education Shijiazhuang 050043 China Innovation Center for Wind Engineering and Wind Energy Technology of Hebei Province Shijiazhuang 050043 China Research Center for Wind Engineering and Engineering Vibration Guangzhou University Guangzhou 510006 China

As a typical blunt body cross-section, Π-shaped composite girders are notably susceptible to vortex-induced vibrations (VIVs). Therefore, it is crucial to investigate their VIV characteristics and develop corresponding aerodynamic countermeasures. In the present study, synchronous pressure and vibration measurements, combined with computational fluid dynamics (CFD) simulations, were conducted for various Π-shaped composite girder models with different main longitudinal beam shapes. The effects of the main longitudinal beam height ( h ), bottom plate width ( b ), and bottom plate inclination angle ( β ) on the vertical VIV were systematically investigated. The underlying mechanisms of VIV for these parameters were discussed by analyzing the time-frequency characteristics of aerodynamic forces, the relationship between local lift forces and vortex-excited forces (VEFs), and flow field characteristics. The results indicate that reducing h , increasing b , or setting β to 20° can suppress vertical VIV, but the suppressive effect varies and is related to the wind attack angle. From the perspective of the flow field, the formation and movement of the large separation vortices at the leading edge of the girder are responsible for the observed vertical VIVs. The aforementioned parameter adjustments that exhibit an excellent VIV suppression effect can reduce the size and suppress the development of the leading-edge vortices, thereby improving the stability of the flow field. From the perspective of aerodynamic force characteristics, these adjustments can reduce the RMS value of the surface pressure coefficient. They can also shift the dominant frequency of the pressure spectrum away from the vibration frequency, weaken the dominant role of the vibration frequency in the overall lift, and greatly reduce the contribution of local lift to the overall vortex-excited forces (VEFs). As a result, VIV is suppressed.

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Localized space-tim e method of fundamental solutions for three-dimensional transient diffusion problem

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Acta Mechanica Sinica 2020年第5期36卷 1051-1057,I0002页

作者： L.Qiu J.Lin Q.-H.Qin W.Chen International Center for Simulation Software in Engineering and Sciences College of Mechanics and MaterialsHohai UniversityNanjing 210098China College of Engineering and Computer Science Australian National UniversityCanberraACT 2601Australia State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China State Key Laboratory of Acoustic Institute of AcousticsChinese Academy of SciencesBeijing 100190China

A localized space-time method of fundamental solutions(LSTMFS)is extended for solving three-dimensional transient diffusion problems in this *** interval segmentation in temporal direction is developed for the accurate simulation of long-time-dependent diffusion *** the LSTMFS,the whole space-time domain with nodes arranged i divided into a series of overlapping subdomains with a simple *** each subdomain,the conventional method of fundamental solutions is utilized and the coefficients associated with the considered domain can be explicitly *** calculating a combined sparse matrix system,the value at any node inside the space-time domain can be *** experi-ments demonstrate that high accuracy and efficiency can be simultaneously achieved via the LSTMFS,even for the problems defined on a long-time and quite complex computational domain.

关键词： Localized spacetime method of fundamental solutions Meshless method Long-time evolution Transient diffusion

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Modeling and experiment study of hydraulically damped rubber mount under larger amplitude excitation at low frequency

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Noise and Vibration Worldwide 2023年第1期54卷 31-43页

作者： Liao, Xin Chen, Lin Wang, Hu Pei, Xin School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China School of Mechanical Engineering Southeast University Nanjing China 14th Institute of China Electronic Technology Corporation Nanjing China

To improve the ride comfort of the cab of construction machinery and reduce the harm of vibration to the driver, a nonlinear lumped parameter model of passive hydraulic damping rubber mount (PHDRM) is first proposed. The nonlinearity of multi-inertial tracks is fully considered. Then, the global FE (finite element) fluid-solid coupling model of the isolator is developed in ABAQUS. The multi-field coupling solution and a joint simulation mode are employed in this paper. Meanwhile, the rubber element and inertial track parameters are identified respectively. Finally, multiple sets of dynamic performance experiments are performed on the different PHDRM samples. The experiment results indicate that the simulation results for two modeling methods of the vibration isolation system are consistent with the experimental datum. The modeling approaches have both reliability and accuracy under larger amplitude excitation at low frequency. Furthermore, the effects of different rubber elements and inertial track of PHDRM on low-frequency dynamic characteristics under larger amplitude are investigated and discussed, respectively. The experimental outcomes also provide a practical reference value for nonlinear modeling method research and dynamic performance analysis of PHDRM with complex structures further. © The Author(s) 2023.

关键词： Rubber

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Numerical analysis of vehicle-bridge coupling vibration concerning nonlinear stress-dependent damping

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Frontiers of Structural and Civil engineering 2022年第2期16卷 239-249页

作者： Pengfei LI Jinquan ZHANG Shengqi MEI Zhenhua DONG Yan MAO Bridge and Tunnel Technology Research Center Research Institute of HighwayMinistry of TransportBeijing100088China National Engineering Laboratory of Bridge Structure Safety Technology Research Institute of HighwayMinistry of TransportBeijing100088China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China School of Civil Engineering Shijiazhuang Tiedao UniversityShijiazhuang050043China

Damping is known to have a considerable influence on the dynamic behavior of *** fixed damping ratios recommended in design codes do not necessarily represent the complicated damping characteristics of bridge *** study investigated the application of stress-dependent damping associated with vehicle-bridge coupling vibration and based on that investigation proposed the stress-dependent damping *** results of the investigation show that the stress-dependent damping ratio is significantly different from the constant damping ratio(5%)defined in the standard *** vehicles travel at speeds of 30,60,and 90,the damping ratios of the bridge model are 3.656%,3.658%,and 3.671%,*** peak accelerations using the regular damping ratio are 18.9%,21.3%,and 14.5%of the stress-dependent damping ratio,*** the vehicle load on the bridge is doubled,the peak acceleration of the mid-span node increases by 5.4 times,and the stress-related damping ratio increases by 2.1%.A corrugated steel-web bridge is being used as a case study,and the vibration response of the bridge is compared with the measured *** acceleration response of the bridge which was calculated using the stress-dependent damping ratio is significantly closer to the measured acceleration response than that using the regular damping ratio.

关键词： vehicle-bridge vibration system dynamic analysis stress-dependent damping energy dissipation

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M-T Scheme for Predicting Effective Diffusion Coefficient of Chloride Ions in Cement-based Materials

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Journal of Wuhan University of Technology(Materials Science) 2020年第3期35卷 520-527页

作者： SUN Guowen ZHANG Jianjian ZHANG Lijuan CAO Tongning WANG Penshuo ZHANG Ying YAN Na State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShiji-azhuang 050043China School of Materials Science and Engineering Shijiazhuang TieDao UniversityShijiazhuang 050043China Foundational Subjects Department Shijiazhuang TieDao University SiFang CollegeShijiazhuang 051132China

To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-phase inclusions is systematically deduced based on the theory of composite mechanics and porous medium. The volume fraction, morphology and distribution of aggregates, as well as the interfacial transition zone (ITZ) are fully taken into consideration in this proposed model. The results show that the algorithm of M-T prediction scheme with high accuracy is relatively simple.

关键词： M-T scheme chloride ion effective diffusion coefficient cement-based materials ITZ

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An improved autogram and its application in bearing fault diagnosis 11

An improved autogram and its application in bearing fault di...

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11th International Conference on Prognostics and system Health Management, PHM-Jinan 2020

作者： Liu, Wenpeng Yang, Shaopu Li, Qiang Liu, Yongqiang Beijing Jiaotong University School of Mechanical Electronic and Control Engineering Beijing China Shijiazhuang Tiedao University State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang China

ISBN: (纸本)9781728151816

Envelope analysis is one of the most advantageous methods in rolling element bearing (REB) diagnosis, but the determination of the informative frequency band (IFB) is always a huge challenge. In order to reduce the influence of discrete frequency components and strong background noise to choose IFB, a new improved Autogram is provided. Firstly, the Cepstrum pre-whitening (CPW) is taken as a preprocessing method to reduce the interference from discrete frequency components in the signal. Then, the Autogram is used to decompose the pre-whitening signal and the optimal IFB is selected for a further demodulation. The simulated signals and a set of experiment signals are taken to verify its validity. The results indicates that this method can successfully address the interference generated by discrete frequency and strong background noise, and effectively extract the weak fault features of bearing. © 2020 IEEE.

关键词： Failure analysis

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An Extension of Correlated Kurtosis to Tunable Q-Factor Wavelet Transform in Fault Diagnosis of Rolling Element Bearings

An Extension of Correlated Kurtosis to Tunable Q-Factor Wave...

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2021 IEEE International Conference on Sensing, Diagnostics, Prognostics, and Control, SDPC 2021

作者： Zhao, Jing Li, Qiang Yang, Shaopu Liu, Yongqiang School of Mechanical Electronic and control Engineering Beijing Jiaotong University Beijing China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

ISBN: (纸本)9781665449762

In engineering practice, the type of rolling bearing failures are typical, and the fault signals are impulsive, which are influenced by the running status, the frequency component of the vibration signals become extremely complicated. Tunable Q-Factor wavelet transform (TQWT) method based on correlation kurtosis is proposed. This method decomposes the bearing fault signal into two different parts, high and low resonance components (HRC and LRC), basing on the different characteristics of signal oscillation. Then, calculating the correlation kurtosis of each decomposition layer of LRC to achieve signal reconstruction. Envelope demodulation analysis is performed on the reconstructed LRC . This method replaces the kurtosis index used in previous studies with correlated kurtosis index, which can effectively eliminate or weaken the influence of peak value interference. Finally, the simulation signals and wheelset bearing test signals are validated. The results show that this method can extract the features of bearing outer, inner and roller under strong background noise. © 2021 IEEE.

关键词： Wavelet transforms

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Development and stability analysis of a high-speed train bearing system under variable speed conditions

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International Journal of mechanical system Dynamics 2022年第4期2卷 352-362页

作者： Baosen Wang Yongqiang Liu Bin Zhang Shaopu Yang School of Traffic and Transportation Shijiazhuang Tiedao UniversityShijiazhuangChina School of Mechanical Engineering Shijiazhuang Tiedao UniversityShijiazhuangChina Department of Electrical Engineering University of South CarolinaColumbiaUSA State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuangChina

During a high-speed train operation,the train speed changes frequently,resulting in motion change as a function of time.A dynamic model of a double‐row tapered roller bearing system of a high-speed train under variable speed conditions is *** model takes into consideration the structural characteristics of one outer ring and two inner rings of the train *** angle iteration method is used to determine the rotation angle of the roller within any time period,solving the difficult problem of determining the location of the *** outer ring and inner ring faults are captured by the model,and the model response is obtained under variable speed *** are carried out under two fault conditions to validate the model *** simulation results are found to be in good agreement with the results of the formula,and the errors between the simulation results and the experimental results when the bearing has outer and inner ring faults are found to be,respectively,5.97% and 2.59%,which demonstrates the effectiveness of the *** influence of outer ring and inner ring faults on system stability is analyzed quantitatively using the Lempel–Ziv *** results show that for low train acceleration,the inner ring fault has a more significant effect on the system stability,while for high acceleration,the outer ring fault has a more significant ***,when the train acceleration changes,the outer ring has a greater *** practice,train acceleration is usually small and does not frequently change in one operation ***,the inner ring fault of the bearing deserves more attention.

关键词： high-speed train bearing model variable speed conditions stability analysis Lempel-Ziv complexity

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Dynamic mechanical characteristics and anti-thaw measures of warm frozen soil

Transportation Engineering

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Transportation engineering 2025年 20卷

作者： Liu, Jiankun Sun, Zhaohui Cui, Yinghui Hu, Tianfei Tai, Bowen School of Civil Engineering & State Key Laboratory for Tunnel Engineering Sun Yat-Sen University Guangzhou 519082 China Institute of Future Civil Engineering Sciences and Technology Chongqing Jiaotong University Chongqing 400074 China China State Railway Group Co. Ltd Beijing 100844 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang 050043 China State Key Laboratory of Cryospheric Science and Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou 730000 China

Permafrost is widely distributed across the Qinghai-Tibet Plateau, and under the influence of climate warming, low-temperature frozen soil is gradually degrading into warm frozen soil. The ratio of ice to unfrozen water in warm frozen soil is highly sensitive to temperature changes, resulting in significant instability in its mechanical properties. To ensure the long-term stability of structures overlying permafrost foundations, conducting research on the mechanical characteristics of warm frozen soil and proposing effective measures to mitigate thaw settlement are crucial. This paper presents the research progress of our team in the field of warm frozen soil dynamics. Using a dynamic triaxial apparatus for frozen soil and a self-developed dynamic direct shear apparatus, we investigated the behavior of warm frozen soil under different temperatures, revealing the influence of temperature on its dynamic stress-strain relationship and dynamic parameters. The development of frozen soil creep theory is reviewed, and advancements in frozen soil dynamics research are summarized and discussed. This paper proposes the use of solar refrigeration technology to protect permafrost, introducing a solar-powered compression refrigeration device and its working principles. The active cooling performance of the device was tested through model experiments and field trials. Additionally, the design and construction techniques of all-season cooling embankments are discussed, providing theoretical and technical support for the stability control of subgrade engineering in permafrost regions. © 2025 The Author(s)

关键词： Active cooling technology Dynamics characteristic Transportation geotechnics Warm frozen soil

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Design and Wave Propagation Characterization of Starchiral Metamaterials

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Acta Mechanica Solida Sinica 2022年第2期35卷 215-227页

作者： Yajun Xin Han Wang Cong Wang Jinxin Yao Qian Ding Haoqiang Gao Shuliang Cheng Yongtao Sun Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province Yanshan UniversityQinhuangdao 060000China Hebei Province Low-Carbon and Clean Building Heating Technology Innovation Center Yanshan UniversityQinhuangdao 060000China Department of Mechanics and Tianjin Key Laboratory of Nonlinear Dynamics and Control Tianjin UniversityTianjin 300072China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang 050043China

Metamaterials with simple artificial topological properties made from industrially produced single-phase materials have extraordinary innovation and *** this paper,we investigated wave propagation characteristics of a hexastarchiral lattice metamaterial with periodic assemblies and used the finite element(FE)method to study the band gap ***,in order to understand the mechanism of band gaps,we discussed the mode shapes of unit cells and found that the bending of the ligament and the overall rotation have a high correlation with the generation of omnidirectional band *** relationships bet ween geometric parameters and band gap properties have also been systematically studied,which demonstrated that the band gaps of the proposed metamaterial could be reasonably predicted through the evolution of geometric ***,the transmission characteristics of finite sandwich panel structures composed of periodic unit cells were calculated to verify the correctness of the band gap simulation results,which proved that the proposed artificial metastructure has potential application value in vibration and noise reduction projects.

关键词： Hexastarchiral lattice metamaterials Band gap properties Finite element method Rotational resonance

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