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International Journal of Mining Science and Technology 2024年第2期34卷 149-165页

作者： Xiaoping Zhou Linyuan Han Jing Bi Yundong Shou School of Civil Engineering Wuhan UniversityWuhan 430072China College of Civil Engineering Guizhou UniversityGuiyang 550025China

High-energy gas fracturing of shale is a novel,high efficacy and eco-friendly mining technique,which is a typical dynamic perturbing *** effectively extract shale gas,it is important to understand the dynamic mechanical properties of *** experiments on shale subjected to true triaxial compression at different strain rates are first conducted in this *** dynamic stress-strain curves,peak strain,peak stress and failure modes of shale are *** results of the study indicate that the intermediate principal stress and the minor principal stress have the significant influence on the dynamic mechanical behaviors,although this effect decreases as the strain rate *** characteristics of compression-shear failure primarily occur in shale subjected to triaxial compression at high strain rates,which distinguishes it from the fragmentation characteristics observed in shale under dynamic uniaxial ***,a numerical three-dimensional Split Hopkinson Pressure Bar(3D-SHPB),which is established by coupling PFC3D and FLAC3D methods,is validated to replicate the laboratory characteristics of *** dynamic mechanical characteristics of shale subjected to different confining stresses are systematically investigated by the coupling PFC3D and FLAC3D *** numerical results are in good agreement with the experimental data.

关键词： dynamic behaviors True triaxial compression High strain rates dynamic failure mechanism PFC3D-FLAC3D coupled method

dynamic behaviors of A Marine Riser Under Two Different Frequency Parametric Excitations

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China Ocean Engineering 2019年第6期33卷 704-712页

作者： XIE Wu-de XU Wan-hai ZHAI Li-bin GAO Xi-feng XU Zeng-wei State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University

The marine risers are often subjected to parametric excitations from the fluctuation top tension. The top tension on the riser may fluctuate with multiple frequencies caused by irregular waves. In this paper, the influence between different frequency components in the top tension on the riser system is theoretically simulated and analyzed. With the Euler-Bernoulli beam theory, a dynamic model for the vibrations of the riser is established. The top tension is set as fluctuating with time and it has two different frequencies. The influences from the fluctuation amplitudes, circular frequencies and phase angles of these frequency components on the riser system are analyzed in detail. When these two frequencies are fluctuating in the stable regions, the riser system may become unstable because ω1+ω2≈2Ωn. The fluctuation amplitudes of these frequencies have little effect on the components of the vibration frequencies of the riser. For different phase angles, the stability and dynamic behaviors of the riser would be different.

关键词： marine risers parametric excitations two different frequency components stability dynamic behaviors

dynamic behaviors of the lump solutions and mixed solutions to a(2+1)-dimensional nonlinear model

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Communications in Theoretical Physics 2023年第5期75卷 52-61页

作者： Si-Jia Chen Xing Lü Yu-Hang Yin Department of Mathematics Beijing Jiaotong UniversityBeijing 100044China Beijing Laboratory of National Economic Security Early-warning Engineering Beijing Jiaotong UniversityBeijing 100044China

In this paper,we propose a combined form of the bilinear Kadomtsev-Petviashvili equation and the bilinear extended(2+1)-dimensional shallow water wave equation,which is linked with a novel(2+1)-dimensional nonlinear *** model might be applied to describe the evolution of nonlinear waves in the *** the effect of a novel combination of nonlinearity and dispersion terms,two cases of lump solutions to the(2+1)-dimensional nonlinear model are derived by searching for the quadratic function solutions to the bilinear ***,the one-lump-multi-stripe solutions are constructed by the test function combining quadratic functions and multiple exponential *** one-lump-multi-soliton solutions are derived by the test function combining quadratic functions and multiple hyperbolic cosine *** behaviors of the lump solutions and mixed solutions are analyzed via numerical *** result is of importance to provide efficient expressions to model nonlinear waves and explain some interaction mechanism of nonlinear waves in physics.

关键词： bilinear form test function mixed solutions dynamic behaviors

Nonlinear dynamic behaviors of ball bearing rotor system

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Journal of Harbin Institute of Technology(New Series) 2009年第2期16卷 284-288页

作者：王黎钦崔立郑德志古乐 School of Mechatronics Engineering Harbin Institute of Technology School of Mechanical and Power Engineering East China University of Science and Technology

Nonlinear forces and moments caused by ball bearing were calculated based on relationship of displacement and deflection and quasi-dynamic model of ***-DOF dynamic equations of rotor supported by ball bearings were *** Newmark-β method and Newton-Laphson method were used to solve the *** dynamic characteristics of rotor system were studied through the time response,the phase portrait,the Poincar?maps and the bifurcation *** results show that the system goes through the quasi-periodic bifurcation route to chaos as rotate speed increases and there are several quasi-periodic regions and chaos *** amplitude decreases and the dynamic behaviors change as the axial load of ball bearing increases;the initial contact angle of ball bearing affects dynamic behaviors of the system *** system can avoid non-periodic vibration by choosing structural parameters and operating parameters reasonably.

关键词： ball bearing rotor system nonlinear bearing force dynamic behaviors

Optimal Initialization and Starting Approach of Synchronous Condenser Integrated Power Grid

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CSEE Journal of Power and Energy Systems 2024年第1期10卷 248-260页

作者： Puyu Wang Xing Liu Qingwen Mou Tao Yuan Tianming Gu Hemin Yang Xiao-Ping Zhang Zhengrong Xiang Chunyi Guo School of Automation Nanjing University of Science and TechnologyNanjing 210094China NARI Group Corporation/State Grid EPRI and also with NARI Technology Co.Ltd. Nanjing 211106China School of Engineering University of BirminghamBirminghamB152TTUnited Kingdom State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

Synchronous condensers(SCs)are generally used at the receiving-end stations of ultra-high-voltage direct current(UHVDC)transmission systems due to their strong reactive power support and flexible regulation of reactive power according to the interconnected grids operating *** this paper,different starting control schemes of a SC integrated power grid are investigated providing four main contributions:1)The principle of reactive power support of the SC on the interconnected power grid is analytically studied,providing the establishment of mathematical models.2)Four different starting control schemes are developed for the initialization and SC integration,*** Scheme 1,a preset initial falling speed is directly utilized without initialization;in Scheme 2,a black start sequential control approach with a static frequency converter(SFC)is proposed;in Scheme 3,PI/PD/PID controllers are respectively applied for the excitation device at the speed-falling stage;in Scheme 4,a pre-insertion approach of an energy absorption component with R/L/RL is utilized to suppress the surges at the SC integration instant.3)The dynamic behaviors of four different starting schemes at specific operating stages are evaluated.4)The success rate of SC integration is analyzed to evaluate starting control *** of the SC interconnected system with four different starting control schemes is evaluated in the timedomain simulation environment PSCAD/EMTDC^(TM).The results prove the superiority of the proposed starting control approach in Scheme 4.

关键词： Black start dynamic behaviors excitation system pre-insertion of energy absorption components starting control schemes static frequency converter(SFC) success rate of integration synchronous condenser(SC)

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揭示鱼鳞降低冰黏附力的奥秘

Science China Materials 2024年第6期67卷 2016-2022页

作者：王锋刘思琪肖森波 Bjørn Skallerud 张志良何健英 Department of Structural Engineering Norwegian University of Science and Technology(NTNU)Trondheim 7491Norway Suzhou Laboratory Suzhou 215000China

近几十年来,大量的研究文献表明,研究人员一直在探究静态表面特性(包括自由能、韧性和弹性)对疏冰性的影响.然而,对于动态表面特性在辅助除冰方面的理解非常有限.在本工作中,我们重点研究了北三文鱼表皮的冰黏附强度,并且观察到了有趣... 详细信息

近几十年来,大量的研究文献表明,研究人员一直在探究静态表面特性(包括自由能、韧性和弹性)对疏冰性的影响.然而,对于动态表面特性在辅助除冰方面的理解非常有限.在本工作中,我们重点研究了北三文鱼表皮的冰黏附强度,并且观察到了有趣的各向异性的冰黏附行为.与顺着鱼鳞生长方向的冰黏附强度(353±95 kPa)相比,逆着鱼鳞生长方向的冰黏附强度(141±47 kPa)降低了60%.我们发现,鱼鳞在受到剪切力的过程中,会发生独特的结构演变,从而导致界面连续断裂,有利于降低冰的黏附性.研究发现,鱼鳞的张开和剥离能力(描述了鳞片在外力下与其下部鳞片和黏结物分离的趋势)可以调控冰的脱落.通过提高鱼鳞的张开和剥离能力,可以在鱼鳞上实现更低的冰黏附强度(66±15 kPa)和更为容易的除冰过程.由于鱼鳞具有出色的机械鲁棒性,这一发现为设计坚硬耐用的防覆冰表面提供了新的视角.

关键词： fish scale ice adhesion dynamic behaviors sequential rupture anti-icing

dynamic performance of submerged floating tunnel with different mooring styles subjected to anchor cable failure

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Frontiers of Structural and Civil Engineering 2023年第10期17卷 1443-1464页

作者： Zhiwen WU Chuhan ZHANG Liwang MOU Guoxiong MEI Ankit GARG College of Civil Engineering and Architecture Guangxi UniversityNanning 530004China Department of Civil Engineering L.N.Gumilyov Eurasian National UniversityNur-Sultan 010000Kazakhstan Guangdong Engineering Center for Structure Safety and Health Monitoring Shantou UniversityShantou 515063China

Submerged floating tunnels(SFTs)are novel structures for transportation across long-and deep-strait *** to severe wave and current excitation as well as the effects of underwater structures and corrosion,the risk of local anchor cable failure is high,which can result in the progressive failure of the entire *** this study,experimental and numerical investigations are conducted to analyze the dynamic behavior of an SFT with different mooring styles under local cable failure.A custom-designed cable failure device and the birth-and-death element method are used to simulate cable failure(i.e.,progressive failure)via experiments and numerical simulation,respectively.A physical-scale segmental model of an SFT with different mooring styles under anchor cable failure is developed in this study.A segmental and entire-length mathematical model is developed using the ANSYS program to perform the numerical *** results of the segmental numerical and experimental models indicate good *** dynamic response of an SFT with different mooring styles under cable failure is comprehensively investigated by investigating the effects of key parameters(wave period,buoyant weight ratio,and cable failure mechanism).Moreover,the progressive failure of the SFT under cable failure is investigated via a segment model test and a numerical simulation of its entire *** present study can serve as a reference for the safer designs of the SFT mooring style.

关键词： dynamic behaviors submerged floating tunnel cable failure mooring style progressive failure

dynamic Modeling for Gas-Electricity Combined Systems with Wind Power and its Stability Control

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2386-2393页

作者： Rui Ma Pingping He Changsha University of Science&Technology Changsha 410114China

The micro turbine(MT)is scheduled to address wind power uncertainties and thus lead to greater variations in the state of natural gas system(NGS).To meet this challenge,first,a dynamic model of a gas-electricity combined system with wind power is established,the dynamic model of the NGS is based on differential equations,so that it can easily connect with the MT model;and a droop control module is added to the Rowen's MT model,so that the improved model can adjust the output power according to the scheduling ***,a stability control method based on the variable regulation ratio gas pressure regulator is proposed,the essence of this method is to reduce the variation of natural gas storage in the gas pipeline,so as to ensure the stability of *** simulation results show that the dynamic model is correct and the stability control method is effective.

关键词： dynamic behaviors integrated energy system stability control method wind power

dynamic Behavior and Vibration Suppression of a Generally Restrained Pre-pressure Beam Structure Attached with Multiple Nonlinear Energy Sinks

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Acta Mechanica Solida Sinica 2023年第1期36卷 116-131页

作者： Yuhao Zhao Jingtao Du Yilin Chen Yang Liu College of Power and Energy Engineering Harbin Engineering UniversityHarbin 150001China

Beam structures are extensively used in many engineering *** marine engineering,the ship shafting system is generally simplified as a vibration model with single or multiple beam structures connected by the coupling *** engineering,multiple nonlinear energy sinks(NESs)can be arranged on the premise of sufficient installation space to ensure their vibration suppression *** engineering practice,this study investigates the dynamic behavior and vibration suppression of a generally restrained pre-pressure beam structure with multiple uniformly distributed NESs,where the prepressure is typically caused by thrust bearings,installation ways,and *** governing equations are derived through the generalized Hamiltonian principle and the variational *** responses of the pre-pressure beam structure are predicted by the Galerkin truncation *** effect of NESs on dynamic responses and vibration suppression of the pre-pressure beam structure is studied and *** parameters of NESs have a beneficial effect on the vibration suppression at both ends of the pre-pressure beam *** can modify the vibration frequency and energy transmission characteristics of the vibration *** different boundary conditions,the optimized parameters of NESs significantly suppress the vibration energy of the pre-pressure beam structure.

关键词： dynamic behaviors Vibration suppression Pre-pressure beam structure Multiple NESs General boundary constraints

Identification of unstable individuals in dynamic networks

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Chinese Physics B 2021年第9期30卷 136-142页

作者： Dongli Duan Tao Chai Xixi Wu Chengxing Wu Shubin Si Genqing Bian School of Information and Control Engineering Xi'an University of Architecture and TechnologyXi'an 710311China School of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 710072China Key Laboratory of Industrial Engineering and Intelligent Manufacturing(Ministry of Industry and Information Technology) Northwestern Polytechnical UniversityXi'an 710072China

To identify the unstable individuals of networks is of great importance for information mining and security *** a broad range of steady-state dynamical processes including biochemical dynamics,epidemic processes,birth-death processes and regulatory dynamics,we propose a new index from the microscopic perspective to measure the stability of network nodes based on the local correlation *** proposed index describes the stability of each node based on the activity change of the node after its neighbor is *** and comparison results show our index can identify the most unstable nodes in the network with various dynamical behaviors,which would actually create a richer way and a novel insight of exploring the problem of network controlling and optimization.

关键词： network dynamic behaviors stability perturbation