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Structural Durability & Health Monitoring 2025年第1期19卷 25-54页

作者： Chao Zhang Shang-Xi Lai Hua-Ping Wang School of Civil engineering and Mechanics Lanzhou UniversityLanzhou730000China Key Laboratory of special Functional Materials and Structural design Ministry of EducationLanzhou UniversityLanzhou730000China

Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the ***,it is particularly signiﬁcant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientiﬁc basis for structural damage identiﬁcation and dynamic model modiﬁ*** view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and brieﬂy describes how to identify structural damages based on the derived modal *** paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),brieﬂy describes damage identiﬁcation methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artiﬁcial intelligence(AI)methods in the direction of modal parameter recognition and damage identiﬁcation is further *** on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identiﬁcation methods are given to provide scientiﬁc references for the optimized design and functional upgrading of SHM systems.

关键词： Structural health monitoring data information modal parameters damage identiﬁcation AI method

STUDY AND APPLICATION OF LARGE FLOATING WHARF IN OPEN SEA AREA

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China Ocean engineering 1990年第1期5卷 117-130页

作者： Li, Jingwu Yi, Jiayu Navy engineering design and Research Bureau of China Beijing China

Along with the development of the navigation of China and the increment of the tonnage of the ships, it is necessary to develop large sized floating wharfs to be used in deep water area. It is the first attempt in the open sea area to construct the 'Qi Tou' large reinforced concrete floating wharf with length of 90 m. This paper focuses on the study and the application of the large reinforced concrete cylinder structure drilled and embeded with the whole section in the rock stratum, and a new type of two-way energy absorption device is fitted on the bracing.

关键词： Water Waves Wave Effects

Membrane flux dynamics in the submerged ultrafiltration hybrid treatment process during particle and natural organic matter removal

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Journal of Environmental Sciences 2011年第12期23卷 1970-1976页

作者： Wei Zhang Xiaojian Zhang Yonghong Li Jun Wang Chao Chen Department of Environmental Science and engineering Tsinghua University Beijing 100084 China Beijing special engineering design and Research Institute Beijing 100028 China

Particles and natural organic matter （NOM） are two major concerns in surface water, which greatly influence the membrane filtration process. The objective of this article is to investigate the efiect of particles, NOM and their interaction on the submerged ultrafiltration （UF） membrane flux under conditions of solo UF and coagulation and PAC adsorption as the pretreatment of UF. Particles, NOM and their mixture were spiked in tap water to simulate raw water. Exponential relationship, （JP/JP0 = a×exp{-k[t-（n-1）T]}）, was developed to quantify the normalized membrane flux dynamics during the filtration period and fitted the results well. In this equation, coefficient a was determined by the value of JP/JP0 at the beginning of a filtration cycle, refiecting the flux recovery after backwashing, that is, the irreversible fouling. The coefficient k refiected the trend of flux dynamics. Integrated total permeability （ΣJP） in one filtration period could be used as a quantified indicator for comparison of different hybrid membrane processes or under different scenarios. According to the results, there was an additive effect on membrane flux by NOM and particles during solo UF process. This additive fouling could be alleviated by coagulation pretreatment since particles helped the formation of flocs with coagulant, which further delayed the decrease of membrane flux and benefited flux recovery by backwashing. The addition of PAC also increased membrane flux by adsorbing NOM and improved flux recovery through backwashing.

关键词： ultrafiltration membrane flux particles natural organic matter hybrid process backwashing

Experimental and numerical investigation on opposing plasma synthetic jet for drag reduction

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Chinese Journal of Aeronautics 2022年第8期35卷 75-91页

作者： Wei XIE Zhenbing LUO Yan ZHOU Wenqiang PENG Qiang LIU Dengpan WANG College of Aerospace engineering National University of Defense TechnologyChangsha 410073China Beijing special engineering design and Research Institute Beijing 100000China

Experimental and numerical studies are carried out to validate the potential of opposing Plasma Synthetic Jet(PSJ)for drag reduction for a ***,flow field changes of opposing PSJ are analyzed by comparing the experimental schlieren images and simulation results in a supersonic free stream of Mach number *** PSJ is a kind of unsteady pulsed jet,the shock standoff distance increases initially and then decreases under the control of PSJ,which corresponds to the change of the strength of ***,the amount of drag reduction of the hemisphere increases initially and then *** is found that there is a short period of“drag rise”during the formation of PSJ before the drag reduction,which is induced by the generation of normal shock waves and the area difference of the cavity wall of PSJ Actuator(PSJA).Secondly,the effects of five parameters,including exit diameter,discharge energy of PSJA,Mach number,static pressure of incoming flow and angle of attack,on drag reduction of opposing PSJ were studied in detail by using numerical *** is found that the Maximum Pressure Ratio(MPR)has a significant impact on the average drag reduction for a configuration-determined *** the configuration selected in this study,the flow field of opposing PSJ shows typical Short Penetration Mode(SPM)in a control cycle of PSJ when the MPR is less than ***,the flow field shows typical Long Penetration Mode(LPM)at some time when the MPR is bigger than *** better drag reduction is achieved in this case.

关键词： Drag reduction Opposing jet Parameter study Plasma synthetic jet(PSJ) Supersonic flow

design and modeling of continuum robot based on virtual-center of motion mechanism

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Frontiers of Mechanical engineering 2023年第2期18卷 143-159页

作者： Guoxin LI Jingjun YU Yichao TANG Jie PAN Shengge CAO Xu PEI School of Mechanical engineering and Automation Beihang UniversityBeijing 100191China Beijing special engineering design and Research Institute Beijing 100143China

Continuum robot has attracted extensive attention since its *** has multi-degree of freedom and high compliance,which give it significant advantages when traveling and operating in narrow *** flexural virtual-center of motion(VCM)mechanism can be machined integrally,and this way eliminates the assembly between ***,it is well suited for use as a continuum robot ***,a design method for continuum robots based on the VCM mechanism is proposed in this ***,a novel VCM mechanism is formed using a double leaf-type isosceles-trapezoidal flexural pivot(D-LITFP),which is composed of a series of superimposed LITFPs,to enlarge its ***,the pseudo-rigid body(PRB)model of the leaf is extended to the VCM mechanism,and the stiffness and stroke of the D-LITFP are ***,the VCM mechanism is combined to form a flexural joint suitable for the continuum ***,experiments and simulations are used to validate the accuracy and validity of the PRB model by analyzing the performance(stiffness and stroke)of the VCM ***,the motion performance of the designed continuum robot is *** show that the maximum stroke of the VCM mechanism is approximately 14.2°,the axial compressive strength is approximately 1915 N/mm,and the repeatable positioning accuracies of the continuum robot is approximately±1.47°(bending angle)and±2.46°(bending direction).

关键词： VCM mechanism continuum robot flexural joint pseudo-rigid body model cable-driven

A Planning Method for Operational Test of UAV Swarm Based on Mission Reliability

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Computer Modeling in engineering & Sciences 2024年第8期140卷 1889-1918页

作者： Jingyu Wang Ping Jiang Jianjun Qi College of Systems engineering National University of Defense TechnologyChangsha410073China Beijing special engineering design Institution Beijing100028China

The unmanned aerial vehicle(UAV)swarm plays an increasingly important role in the modern battlefield,and the UAV swarm operational test is a vital means to validate the combat effectiveness of the UAV *** to the high cost and long duration of operational tests,it is essential to plan the test in *** solve the problem of planning UAV swarm operational test,this study considers the multi-stage feature of a UAV swarm mission,composed of launch,flight and combat stages,and proposes a method to find test plans that can maximize mission ***,a multi-stage mission reliability model for a UAV swarm is proposed to ensure successful implementation of the mission.A multi-objective integer optimization method that considers both mission reliability and cost is then formulated to obtain the optimal test *** study first constructs a mission reliability model for the UAV swarm in the combat ***,the launch stage and flight stage are integrated to develop a complete PMS(Phased Mission Systems)reliability ***,the Binary Decision Diagrams(BDD)and Multi Objective Quantum Particle Swarm Optimization(MOQPSO)methods are proposed to solve the *** optimal plans considering both reliability and cost are *** proposed model supports the planning of UAV swarm operational tests and represents a meaningful exploration of UAV swarm test planning.

关键词： UAV swarm PMS MOQPSO BDD mission reliability operational test planning

Analytical solution for vertical site response analysis and its validation

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Earthquake engineering and engineering Vibration 2019年第1期18卷 53-60页

作者： Liu Junwei Zhang Xiao Cao Zewei Han Bo Yang Shizeng School of Civil engineering Qingdao University of Technology School of Civil engineering Shandong University Nantong Municipal engineering design Institute Co. Ltd. Huangdao Municipal Water Resources bureau

Existing studies for site response analysis in geotechnical earthquake engineering have widely concentrated on the horizontal component of the ground motion. However, strong vertical ground motions have been repeatedly observed, resulting in significant vertical compression damage of engineering structures. Furthermore, for the seismic design of critical structures(e.g. large-scale dams and nuclear power plants), the ground motions in all three directions should be considered. Therefore, there is a need to investigate the site response subjected to the vertical component of the ground motion, especially for the seismic design of critical structures. Consequently, in this study, a numerical program for vertical site response analysis is proposed based on the commonly used analytical transfer function method. The proposed program is then validated against well-documented case studies obtained from the Japanese KiK-net(Kiban Kyoshin network) downhole array monitoring system. Results show that the response spectra at the ground surface are well predicted in the low frequency range(<5 Hz), while discrepancies are observed in the high frequency range. However, the high frequency discrepancies do not significantly affect the overall prediction accuracy, as the overall seismic response of geotechnical structures are usually dominated by low frequency vibrations. Furthermore, the limitations in the analysis are also discussed.

关键词： site response analysis vertical ground motions transfer function analytical solution

Floating Clamping Mechanism of PT Fuel Injector and Its Dynamic Characteristics Analysis

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Chinese Journal of Mechanical engineering 2012年第3期25卷 550-556页

作者： WANG Xinqing LIANG Sheng XIA Tian WANG Dong QIAN Shuhua engineering Institute of engineering Corps University of Science&Technology of Chinese People's Liberation ArmyNanjing 210007China bureau of Navy engineering design&Research Beijing 100841China

PT fuel injector is one of the most important parts of modern diesel *** satisfy the requirements of the rapid and accurate test of PT fuel injector,the self-adaptive floating clamping mechanism was developed and used in the relevant *** dynamic characteristics directly influence the test efficiency and ***,due to its special structure and complex oil pressure signal,related documents for evaluating dynamic characteristics of this mechanism are lack and some dynamic characteristics of this mechanism can＇t be extracted and recognized effectively by traditional *** at the problem above-mentioned,a new method based on Hilbert-Huang transform（HHT） is ***,combining with the actual working process,the dynamic liquid pressure signal of the mechanism is *** analyzing the pressure fluctuation during the whole working process in time domain,oil leakage and hydraulic shock in the clamping chamber are ***,owing to the nonlinearity and nonstationarity of pressure signal,empirical mode decomposition is used,and the signal is decomposed and reconstructed into forced vibration,free vibration and *** analyzing forced vibration in the time domain,machining error and installation error of cam are ***,free vibration component is analyzed in time-frequency domain with HHT,the traits of free vibration in the time-frequency domain are *** with traditional methods,Hilbert spectrum has higher time-frequency resolutions and higher *** improved mechanism based on the above analyses can guarantee the test accuracy of injector *** new method based on the analyses of the pressure signal and combined with HHT can provide scientific basis for evaluation,design improvement of the mechanism,and give references for dynamic characteristics analysis of the hydraulic system in the interrelated fields.

关键词： PT fuel injector floating clamping mechanism dynamic characteristics analysis Hilbert-Huang transform

THEORETICAL ANALYSIS AND EXPERIMENTAL VERIFICATION ON TERNARY-WAVES METHOD TO COMPILE ACCELERATED SPECTRA

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Chinese Journal of Mechanical engineering 2002年第4期15卷 308-313页

作者： Xiong Junjiang Wu Zhe Gao ZhentongAircraft design bureau, Beijing University of Aeronautics and Astronautics,Beijing 100083, China Aircraft design bureau Beijing University of Aeronautics and Astronautics 北京 100083

The equivalent damage calculation formulae of fatigue crack formation andgrowth are established. In order to compile the fatigue crack formation and growth accelerated loadspectra, the main wave shapes and load sequence of the actual load spectrum are kept constant, andthe carrier waves are cut off. And secondary waves are put together into new secondary waves toshorten the test time according to the equivalent damage calculation formulae respectively. Then bythe fatigue cumulative damage calculation of the fatigue crack formation and growth accelerated loadspectra, the one corresponding to the bigger damage is determined as the fatigue accelerated testload spectrum. Therefore in the test process, the fatigue accelerated test spectrum may be appliedtill fatigue failure, the engineering fatigue crack length of full-scale structure need not beinspected, and the fatigue crack formation accelerated load spectrum need not be transferred intothe fatigue crack growth accelerated load spectrum. Finally, it is verified by tests of two kinds ofspecimens that the damages of the specimens caused by the accelerated load spectra are near tothose by the actual load spectra; namely, the tested life of actual load spectra is similar to thatof accelerated load spectra. But the test time of accelerated load spectra is shortened by aboutthree-quarters that of actual load spectra. From these tests, it is also found that the fatigueaccelerated test spectrum has an advantage over FALSTAFF spectra.

关键词： ternary-waves actual load-time history accelerated load spectra equivalent damage calculation main wave secondary wave carrier wave

Experimental research on the mechanism of non-monotonic characteristic between curing temperature and mechanical behaviors of Kevlar/epoxy composite

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Science China(Technological Sciences) 2018年第7期61卷 1012-1020页

作者： LIU Li HU DeAn ZHANG YouMin HAN Xu State Key Laboratory of Advanced design and Manufacturing for Vehicle Body Hunan University Key Laboratory of Advanced design and Simulation Technology for special Equipments Ministry of Education Hunan University School of Mechanical engineering Hebei University of Technology

An experimental procedure is conducted to investigate the mechanism of the non-monotonic characteristic between curing temperature and mechanical behaviors of the Kevlar/epoxy composite in macro and micro levels. Different specimens are fabricated at four different curing temperatures and tested with ±45° off-axis tensile loading on a universal test machine coupled with digital image correlation(DIC). Moreover, the environmental scanning electron microscope(SEM) was used to obtain the micrographs and reveal their mechanism. The tested results show that the tensile mechanical behaviors are sensitive to the curing temperature and the relationship is non-monotonic. Also, as the temperature increases, the thicknesses of the specimens are significantly enlarged. By analyzing the SEM micrographs of the matrix grooves in the damage zone and DIC strain contours, it is concluded that the non-monotonic relationship is dominated by the properties of the Kevlar/epoxy interfaces and deformation of the distorted fibers.

关键词： Kevlar/epoxy composite mechanical behavior digital image correlation SEM micrograph non-monotonic character-istic distorted fiber