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第八届国际振动工程会议

作者： Enli chen Minghao Wang Meiqi Wang Yujian chang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University School of Mechanical Engineering Shijiazhuang Tiedao University School of Electrical and Electronic Engineering Shijiazhuang Tiedao University

The internal friction can be described more accurately by fractional damping than integral damping. The nonlinear dynamic response characteristics of SD oscillator with fractional damping under harmonic excitation are studied. The Fourier equivalent model is proposed to solve the nonlinear stiffness of the differential equation of system motion. The non-integrable nonlinear stiffness of the differential equation of the system is solved. The expression of amplitude-frequency response is obtained by solving the differential equation of system motion using the average method,and the stability of periodic solution is determined based on the Lyapunov stability theory and the Routh criterion. The results show the Fourier transform equivalent model of the nonlinear stiffness term of the SD oscillator can be applied to the motion characteristic of the system with large amplitude, which greatly improves the calculation accuracy. With the same damping coefficient, the amplitude-frequency response of the fractional damping system is different from that of the integral damping system, the resonance frequency and amplitude of the fractional damping system vary greatly. changing the fractional coefficient will change the amplitude-frequency response backbone curve of the fractional damping system, but the integral damping system is not affected. When the fractional order is changed, the amplitude of the fractional damping system changes opposite on both sides of the cut-off point.

关键词： SD oscillator fractional damping backbone curve nonlinear vibration

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Nonlinear Vibration Analysis of Electric Vehicle-Road-Motor coupling system

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SSRN 2024年

作者： Feng, Guizhen Li, Shaohua State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Hebei Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Hebei Shijiazhuang050043 China

The excessive unsprung mass of the in-wheel motor driving electric vehicles (IWMEV) leads to the tire dynamic load increasing, the vehicle-road coupling effect is more complex, which in turn causes road surface vibration and secondary road excitation. At the same time, uneven road surface and secondary road excitation will cause the wheel to jump, and the dynamic fluctuation of motor air gap and the unbalanced electromagnetic force will further deteriorate the performance of IWMEV. The nonlinear dynamic model with 11-degree-of-freedom vehicle-road-motor coupling system is established, the differential equation of vertical vibration of the nonlinear viscoelastic foundation sandwich plate road system is derived with the Galerkin method and trigonometric product and formula, the motor air gaps and the unbalanced electromagnetic force under the excitations of random road and vehicle-road coupling are calculated. The effects of multiple excitations such as electromagnetic excitation, road surface irregularity and secondary road excitation caused by vehicle-road coupling, as well as the influence of suspension nonlinear parameters and vehicle speed on road and vehicle response are analyzed. The results show that the rotor eccentricity, motor air gap fluctuation and unbalanced electromagnetic force are disturbed by the uneven road and vehicle-road coupling, and the amplitude-frequency characteristics of electromagnetic excitation are closely related to these factors. When driving at low speed on a relatively smooth road, the effects of vehicle-road coupling and electromagnetic excitation on the relative difference of vehicle response should be paid attention to. In order to improve the ride comfort, it is advantageous to increase the square nonlinear coefficient of suspension stiffness and the asymmetry coefficient of suspension damping. © 2024, The Authors. All rights reserved.

关键词： Electric excitation

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compressive Sensing Reconstruction for Rolling Bearing Vibration Signal Based on Improved Iterative Soft Thresholding Algorithm

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SSRN 2022年

作者： Wang, Haiming Yang, Shaopu Liu, Yongqiang Li, Qiang School of Mechanical Electronic and Control Engineering Beijing Jiaotong University Beijing010044 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

A new method of acquisition and reconstruction based on compressive sensing theory is introduced in this paper. An improved ISTA (IISTA) is proposed. Firstly, an acceleration operator considering step size is proposed to estimate the gradient, which can accelerate convergence speed. Then for breaking the limitation of fixed internal gradient step size, a bidirectional search principle is introduced to backtrack its iteration step size. Finally, the constraints of the quadratic approximation model on the reconstruction objective function is proposed to adaptively determine optimal iteration step size. The effectiveness of the method is verified by the reconstruction of bearing vibration signals in different health states. The results show that the proposed method can achieve convergence faster, improve the sparsity of the regular term, and has a better reconstruction performance than the conventional ISTA under different sampling rates. © 2022, The Authors. All rights reserved.

关键词： compressed sensing

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Parametric Influences of Stability and Settlement Pattern of Embankment on Slope Foundation 4

Parametric Influences of Stability and Settlement Pattern of...

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2020 4th International conference on Water conservancy, Hydropower and Building engineering, WcHBE 2020

作者： Zhang, Ouyang Yang, Guangqing Zhao, Yunfei Lu, Huali Hou, Licheng Third Construction Engineering Company Ltd. China Construction Second Engineering Bureau Ltd. Beijing100070 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China China State Construction Engineering Corp. Ltd Beijing100020 China

Building a subgrade on the slope foundation is common for highway constructions in china. Under different hydrogeological conditions, the stability and differential settlement are the main problems for the construction of the subgrade. In order to study the parameters that influence the stability and deformation of subgrade, based on the cross-section of a mountainous region highway, those simulations were conducted to study the influence of subgrade height, subgrade width, embankment slope angle, and slope foundation angle on the stability and pattern of embankment. The results showed that the allowable filling height is 15 m;otherwise, there is a large risk of the slope sliding. Further, it was found that the maximum vertical deformation on the right shoulder of the embankment increases with an increase in the angles of the slope of the foundation. These results provide references for future highway constructions and design works in mountainous areas. © Published under licence by IOP Publishing Ltd.

关键词： Deformation

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A small-scale experimental study of cO_(2) enhanced injectivity methods of the high-rank coal

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Petroleum Science 2021年第5期18卷 1427-1440页

作者： Qing-He Niu Li-Wen cao Shu-Xun Sang Wei Wang Wei Yuan Jiang-Fang chang Xiao-Jun Jia Wei-Min Zheng Zeng-Xue Zhang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao UniversityShijiazhuang050043China Hebei Technology and Innovation Center on Safe and Efficient Mining of Metal Mines Shijiazhuang050043China School of Resource and Earth Science China University of Mining and TechnologyXuzhou221008China Jiangsu Key Laboratory of Coal-based Greenhouse Gas Control and Utilization China University of Mining and TechnologyXuzhou221008China Hebei Academy of Emergency Management Shijiazhuang050081China Hebei Iron and Steel Group Mining Co. LtdTangshan063000China Minmetals Mining Holding Co. LtdHefei241000China

The attenuation of cO_(2)injectivity has become the biggest technical barrier for the application of cO_(2)enhanced coalbed methane recovery(cO_(2)-EcBM).commonly,the intermittent cO_(2)injection,N2 displacing cO_(2)and pre-fracturing are the potential cO_(2)enhanced injectivity methods for coal reservoirs,but their mechanism and effectiveness remain to be *** paper thus conducted small-scale experiments to simulate the working process of these engineering measures by an independently developed experimental *** show that the cO_(2)injectivity of coal is remarkably improved by the intermittent injection mode since the cO_(2)injection time is increased by folds and the loss of reservoir pressure can be complemented in *** N_(2)displacing cO_(2)method promotes the desorption of cO_(2)and reduces the swelling strain,with the result that the permeability of coal is improved by 74.82%and 64.95%compared with the methods of the primary subcritical cO_(2)(Sub cO_(2))and supercritical cO_(2)(Sc cO_(2))***,the permeability reduces again with the secondary cO_(2)*** permeability of the coal sample after pre-fracturing is averagely improved by 1-2 orders of magnitude,the irreversible permeability loss rate,average stress sensitivity coefficient and the permeability loss rate due to adsorption are averagely reduced by 95.885%,61.538%and 96.297%,*** indicates that the permeability of coal after pre-fracturing is no longer sensitive to both the effective stress and Sc cO_(2)adsorption,the injectivity is thus improved and *** cO_(2)enhanced injectivity effects of the intermittent cO_(2)injection,the N_(2)displacing cO_(2)and the pre-fracturing are various,which thus can be selected individually or jointly to improve the cO_(2)injectivity according to the reservoir physical properties and geological *** research deepens the understanding of the functional mechanism of cO_(2)enhanced injectivity method

关键词： Supercritical cO_(2) Permeability Intermittent injection N_(2)displacing cO_(2) Pre-fracturing

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A new control strategy for high speed train and its simulation analysis

A new control strategy for high speed train and its simulati...

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第八届国际振动工程会议

作者： Yiwei Zhao Shaopu Yang Yongqiang Liu Yingying Liao State Key Laboratory of Mechanical behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Department of Transportation Shijiazhuang Tiedao University Department of Mechanical Engineering Shijiazhuang Tiedao University Department of Civil Engineering Shijiazhuang Tiedao University

For a long time, the dynamic performance of high-speed train has been studied by many experts. And it will continue to be studied in the future with the rapid development of high-speed trains. The ride comfort and safety of trains which is the part of the dynamic performance is studied in this paper through applying the control method to the secondary lateral dampers and yaw dampers. Firstly, a train model is built by multi-body dynamics software UM. Then the co-simulation model is built in Simulink for the further study. The second, the multi-objective optimization for the damper damping coefficient of the secondary lateral dampers and yaw dampers is carried out in a straight track. The optimal damping coefficient that can improve the ride comfort and safety simultaneously is obtained. The objectives of optimization are the lateral acceleration and derailment coefficient. Similarly, the multi-objective optimization for the damping coefficient of the two kind of dampers is carried out in a curve track. The optimal damping coefficient is obtained. In order to keep the ride comfort and safety of the train, no matter in a straight track or in a curve track, the semi-active control method is proposed to adjust the damping coefficient. In this way, the damping coefficients of the two kinds of shock absorbers are always ***, the train model is simulated and *** results show that the control method that the two kinds of shock absorbers are controlled at the same time can significantly improve the ride comfort and safety of the train whether it's running in a straight track or a curve track. In other words,multi-point control can improve the train dynamic performance comprehensively.

关键词： high-speed train co-simulation semi-active ride comfort safety

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Sub-Preferential Rotational Wave Beaming in Structurally Rhombus Re-Entrant Honeycombs

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SSRN 2023年

作者： Zhu, Zhiwei Deng, Zichen State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China MIIT Key Laboratory of Dynamics and Control of Complex Systems Northwestern Polytechnical University Xi'An710072 China

Rotational waves frequently manifest in micro-structured materials and are often coupled with classical shear or longitudinal wave modes. In this study, a distinctive isolated optical branch, exhibiting very high polarization index related to joint rotation motion, is found in dispersion diagram of elastic wave propagation in structurally rhombus re-entrant honeycomb (SSRH). Through an analysis of group velocity, we further explore the wave beaming of the rotational wave propagation within the SRRH, and intriguingly, observe the emergence of sub-preferential wave beaming occurring along the short diagonal directions. This dynamic anisotropic phenomenon stems from the intricate interplay between wave frequency and structural topology. To elucidate the underlying dynamic anisotropy of rotational waves, we propose a simple rigid-spring model and derive an anisotropic coefficient that precisely captures the intricate frequency-structure coupling behavior. The obtained anisotropic coefficient unveils the formation of sub-preferential directions of the rotational wave within the SRRH. Our findings transcend the elucidation of dynamic anisotropy in lattice materials, extending to practical implications encompassing the manipulation of elastic wave propagation and the design of waveguides. © 2023, The Authors. All rights reserved.

关键词： Anisotropy

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Erratum: ‘Scattering of SH Waves Around circular canyon in Inhomogeneous Wedge Space’

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Geophysical Journal International 2021年第1期226卷 345-350页

作者： Zailin Yang Xinzhu Li Yunqiu Song Guanxixi Jiang Menghan Sun Xueqian Fang College of Aerospace and Civil Engineering Harbin Engineering University Harbin China Key Laboratory of Advanced Material of Ship and Mechanics Ministry of Industry and Information Technology Harbin Engineering University Harbin China sunmenghan163@*** State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang China

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Evolution Rule of Wheel Tread Wear of High-Speed Train and its Influence on Dynamic Performance

Evolution Rule of Wheel Tread Wear of High-Speed Train and i...

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International conference on Sensing, Diagnostics, Prognostics, and control (SDPc)

作者： Peng Wang Zhenkai Liu Yongqiang Liu Shaopu Yang Yuqiang cai College of Mechanical Engineering North China University of Science and Technology Tangshan China 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

ISBN: (数字)9798350388855

ISBN: (纸本)9798350388862

To investigate the influence of wheel wear evolution on wheel-rail contact and dynamic performance of high-speed trains, taking a high-speed train as the research object, the wheel wear tracking test was carried out to analyze the evolution law of wheel wear with the running mileage. Using the wheel-rail contact geometric relationship and non-Hertz rolling contact theory, the influence of wheel wear on wheel-rail contact geometric characteristics and contact mechanical characteristics was calculated, and the wheel-rail matching performance under wear was analyzed. The vehicle model was established by UM software, and the influence of different wheel wear treads on the vehicle's dynamic performance in a lathing cycle was investigated. The results indicate that during the evolution of wheel profile, the distribution state of wheel-rail contact points changes. With the increase of wheel tread wear, the radius difference of wheel rolling circles increases, which is conducive to improving the curve passing performance of vehicles. The wear of wheel tread leads to the increase of vehicle transmissibility and the decrease of nonlinear critical speed.

关键词： Vibrations Suspensions (mechanical systems) Stability criteria Wheels Flanges Market research Software Sensors Indexes Vehicle dynamics

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Effect of Tamping Energy on the Reinforcement of a High Embankment Filled with Soil-Rock 4

Effect of Tamping Energy on the Reinforcement of a High Emba...

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2020 4th International conference on Water conservancy, Hydropower and Building engineering, WcHBE 2020

作者： Hou, Licheng Yang, Guangqing Jin, Jing Lu, Huali Zhang, Ouyang Third Construction Engineering Company Ltd. China Construction Second Engineering Bureau Ltd. Beijing100070 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang Hebei050043 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang Hebei050043 China School of Civil Engineering Hebei University of Science and Technology Shijiazhuang Hebei050018 China China State Construction Engineering Corp. Ltd Beijing100020 China

Through dynamic compaction tests with tamping energies of 1500, 2000, and 2500 kN•m of an embankment section in the PingShan-ZanHuang Expressway, the compression deformation behavior of the tamping settlement, soil deformation around the tamping rammer, consolidation depth, and dynamic stress of dynamic compaction were comprehensively tested. comparative analyses of field data under three different tamping energies suggested that the optimal tamping energy, number of strikes, and vertical effective tamping depth for this embankment are 2000 kN•m, six, and 5 m, respectively. The field test data proving that dynamic compaction has a significant effect on this embankment. © Published under licence by IOP Publishing Ltd.

关键词： Embankments

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