15 March 2023, Volume 42 Issue 5
    

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  • XU Wanhai, AI Huanan, JIA Kun, MA Yexuan
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 1-6.
    Abstract ( 185 ) Download PDF ( 110 )   Knowledge map   Save
    In this paper, a complete towing tank test system is designed by considering the fluid-solid-soil coupling and combining the existing experimental conditions. The experimental system can completely test and study the influence of structure properties, incoming flow velocity, and pretension on vortex-induced vibration of multi-span pipelines, providing reference and verification for subsequent theoretical research and numerical simulation of vortex-induced vibration of multi-span pipelines. It is proved that the system can simulate the vortex induced vibration of multi-span pipelines. The research results in this paper provide a new idea for the experimental study of the multi-span mechanism of multi-span pipelines, and provide data reference for the subsequent vortex-induced vibration experiments of multi-span pipelines.
  • ZENG Dongping1, KANG Yong2, LIU Zhong1, YU Zheqing1, LI Jiamin2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 7-12.
    Abstract ( 169 ) Download PDF ( 114 )   Knowledge map   Save
    In order to explore the influence of driving pressure modulation on the dynamic characteristics and injection performance of the controllable jet injection system, a high-precision jet pressure test platform and a high-speed photographic device were used to test and analyze the jet impact characteristics and diffusion characteristics. Combined with the experimental results of in vitro tissue injection, the mechanism of driving pressure modulation was explored. The results show that the requirements of the high and low two-stage jet velocity of the controllable jet injection system can be achieved by switching the driving pressure. And with the regulation of driving pressure, the impact and diffusion characteristics of the jet injection system can be controlled. Also,there are optimal driving pressure combinations for different injection volume conditions. The optimal driving pressure combination of 1.0 mL (a typical large-dose injection condition) is (1.00-0.25) MPa. Thus, the injection effect of the jet injection system can be improved by driving pressure modulation.
  • HUANG Jiangcheng1, XIAO Zhengming1, LIU Tao1, LIU Weibiao2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 13-20.
    Abstract ( 167 ) Download PDF ( 81 )   Knowledge map   Save
    The porous honeycomb has good energy absorption and vibration isolation characteristics. However, the research on traditional honeycomb base is mainly focused on the effect of increasing or decreasing uniform parameters on vibration isolation performance, which is prone to the defects of stress concentration and low in-plane stiffness and poor bearing capacity. Therefore, in this study, we propose a cylindrical honeycomb base and analyze its non-deformability resistance through simulation. on the premise of satisfying certain vibration isolation performance, reasonable design parameters of the base can be optimized by optimizing the sequential quadratic programming algorithm built into the software, and then conduct hierarchical gradient design based on the optimized base parameters. The hierarchical gradient design is based on the constant mass volume of the base and taking cell wall thickness and concave angle as independent variables to design the honeycomb layer with the pathwise thickness gradient, the inverse thickness gradient, the pathwise angle gradient, the inverse angle gradient. The results show that the cylindrical honeycomb base has higher specific stiffness and stronger bearing capacity compared with the regular square base. In addition, this study also indicate that compared with uniform parameter design, thickness gradient design has better vibration isolation performance, inverse thickness gradient design has the best vibration isolation effect, and angle gradient design has no obvious influence on vibration isolation performance.
  • ZHAO Lijie1,2,3, JING Xuanguang2, DU Yongfeng3, SHEN Jinsheng1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 21-29.
    Abstract ( 169 ) Download PDF ( 54 )   Knowledge map   Save
    As a combination of variable stiffness and strong nonlinear components, series isolation members are the most vulnerable and sensitive parts of column top isolation structures.In order to have a deeper understanding of the nonlinear mechanical properties of the series isolation members, this paper carried out pseudo-static loading tests on the series isolation members with different slenderness ratios and axial compression ratios, and analyzed the failure phenomenon and characteristics of the series isolation members with different slenderness ratios and axial compression ratios.The effects of slenderness ratio and axial pressure ratio on the horizontal stiffness, strength, force and displacement relations of series isolation components were analyzed, and the evolution law of mechanical properties of series isolation components caused by nonlinear cumulative damage under multiple real-time reciprocating loads was investigated. The analysis of test results shows that ductility, energy dissipation capacity and ultimate displacement of components are negatively correlated with slenderness ratio and axial compression ratio and show obvious nonlinear characteristics. The increase of slenderness ratio and axial compression ratio will cause damage and deterioration of some nonlinear mechanical properties such as horizontal stiffness and strength of series isolation components.
  • TU Wenbing, ZHANG Guiyuan, LUO Ya, CHEN Chao, LIANG Jie, YANG Benmeng
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 30-38.
    Abstract ( 180 ) Download PDF ( )   Knowledge map   Save
    Most of the traditional methods to analyze the vibration characteristics of rolling bearing are based on the ideal Hertz contact theory. However, when the bearing slips, the sliding phenomenon will appear between the rolling element and the raceway. Therefore, the sliding contact problem between the rolling element and the raceway is beyond the hypothetical scope of Hertz theory. To solve this problem, the sliding non-ideal Hertzian contact between the rolling element and the inner or outer raceways is proposed in this paper. The load-deformation formula and deformation coefficient are obtained through theoretical analysis and contact finite element model; Based on the sliding non ideal Hertz contact theory, the dynamic model of cylindrical roller bearing is established, and the effects of Hertz and sliding contact on the vibration characteristics of bearing are compared and analyzed. The research shows that the vibration signal of bearing under sliding contact has hysteresis phenomenon. The vibration level of bearing is higher than that of Hertz contact at low speed, but lower at high speed; At the same time, compared with Hertz theory, the effect of relative sliding of contact surface is further considered, which is closer to the actual working condition of bearing.
  • YU Yang1,2, ZHANG Xiaoming1,2, LI Zhenmian1,2, ZHOU Junlong3, CHENG Siyuan1,2, YU Jianxing1,2, YANG Zhenglong1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 39-46.
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    Due to earthquakes, faults, landslides and settlements, the leg foundation under a tension leg platform (TLP) may move. Based on the once-a-year design condition of Liuhua Oilfield in the South China Sea, the time history of the dynamic response of the platform system under 16 cases with the foundation moves down 0.1 meters is calculated. The amplitude and standard deviation of the six DOFs motion as well as the mooring tension in different cases were compared. The results show that the foundational movements have significant impacts on the amplitude of the six DOFs response and tension leg tension, but do not aggravate the fluctuations of these responses; the foundational movements will destroy the original symmetry of the platform system and lead to a greater deterioration in the heave motion; the foundational movements will increase leg tensions significantly and there is a risk of tension leg breakage and mooring failure.
  • CHEN Yifei, HE Haoxiang, LAN Bingji, SUN Haoding
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 47-56.
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    In order to improve the economy of traditional frame core tube (FCT) structural system, a new high-rise structural system of frame-distributed tube-core tube (FDCT) is proposed to reduce the enclosed area of traditional tube. Furthermore, the frame-distributed rocking tube-core tube (FDRCT) high-rise structural system is proposed to improve the reduced seismic capacity of FDCT due to the weakened stiffness. According to the simplified mechanical models of FCT, FDCT and FDRCT, the three structural dynamic equations are established based on Lagrange Equation. By analyzing the time history response of the structure subjected to earthquake and the effect of mass parameter of distributed rocking tube, it is proved that the FDRCT structure with rocking system has excellent energy dissipation and damping performance. The dynamic time history analysis of the three structures under different site conditions and different types of long-period earthquake waves is carried out, and the results show that the FDRCT structure could has energy dissipation and damping effect under different types of earthquake waves, and it is superior under long-period seismic waves. By evaluating the performance-profit value of the three structures, it show that the FDRCT structure can improve the structural economy and ensure the safety performance under different types of earthquake waves.
  • ZHANG Yun1, WANG Cong1, WANG Xiaorong2, ZHANG Shaohua1, ZHANG Hongli1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 57-65.
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    Taking DC-DC Boost converter system as the research object, a multi-scale coupled dynamic model under both parametric and external excitations is established. When the system exhibits a strict resonance relationship and there is a magnitude difference between the parameter, external excitation frequency and the natural frequency of the system, the two excitation terms are transformed into a function of a single periodic excitation term, which is used as a slow-changing parameter to obtain a generalized autonomous fast subsystem. The complex mode oscillation behavior of the system under three typical excitation frequency ratios is studied. With the help of single-parameter and two-parameter bifurcation diagrams, complex spectral entropy diagrams, and phase transition diagrams, the generation mechanism and non-smooth dynamic behavior characteristics of asymmetric smooth Fold-nonsmooth Fold type and periodically symmetric nonsmooth Fold-Fold type modes oscillation are analyzed. In particular, the trajectory structure, the number of non-smooth interfaces crossed, the number of cluster bifurcations, etc. of the system at different frequency ratios all change, resulting in complex mode oscillations with different number of vortices. This study provides a theoretical basis and an auxiliary analysis model for the study of cluster oscillation of correlated coupling circuits.
  • QU Minghe, WU Shaopei, YU Liyang, DING Wangcai, LI Guofang, HUANG Ran
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 66-73.
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    The fractional nonlinear Zener model is used to describe the nonlinear and viscoelastic constitutive relation of the vibration isolation system. The fractional-order derivative term was made equivalent to a term in the form of trigonometric function, the steady-state response of the system was solved by high-order harmonic balance method, and the results were compared with a variety of methods. The dynamic response of the system in the low frequency region was obtained by using numerically simulation. The bifurcation type of the system was determined by Floquet theory and the influence of fractional order term on dynamic response was revealed. The results show that there is a jump phenomenon in high-order super-harmonics, and periodic motion diversity in the process of adjacent-order super-harmonic transfer. Additionally, it is found that the periodic motion and chaos coexist in the system, and the transition laws of the polymorphic coexistence region and its adjacent regions was summarized explicitly.
  • NI Junshuai1,2, HU Changqing1, ZHAO Mei1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 74-82.
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    Aiming at the problem of ship target recognition at sea with low signal-to-noise ratio, the traditional convolutional neural network is improved and combined with variational modal decomposition, a ship radiated noise recognition method based on Variational Modal Decomposition(VMD) and improved Convolutional Neural Network(CNN) is proposed. The proposed method is applied to identify 12 ship targets with radiated noise signal-to-noise ratio lower than 5dB in the East China Sea experiment, and the average accuracy is 98.6%; Compared with the other 7 recognition methods, it increased by 24.8%, 17.0%, 15.1%, 8.0%, 13.1%, 16.8% and 5.2% respectively; Compared with the traditional convolution network, the improved convolution network has obvious advantages in computation and recognition rate.
  • WU Xingxia1,2, ZHENG Shansuo1,2, LIU Xiaohang1,2, YANG Feng3, LI Yongming1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 83-91.
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    As one of the important basic facility in substation, the seismic performance of substation insulators directly affects the seismic reliability of substation system. Using quasi-static loading test, the aseismic performance of substation insulators is discussed from three aspects: height, axial pressure ratio and number of insulators assembled. Bearing capacity, deformation capacity, hysteresis curve, and energy dissipation capacity are analyzed based on the above parameters. The test results show that all insulator specimens undergo bending failure after quasi-static loading test. The bearing capacity and energy dissipation capacity of the specimens gradually deteriorate with the increase of the height of the specimens. As the number of insulators decreases, The peak bearing capacity and energy consuming capacity of each insulator decreases as the number of insulators increases. Finally, a refined finite element model is established based on experiments and its reliability is verified, which lays a foundation for subsequent seismic analysis of power system.
  • LEI Hao1,2,3, WU Honggang2, QIAN Jiangu1, LAI Tianwen3, JI Zhiyang3, LIANG Yu3
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 92-100.
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    To study the dynamic response of the 3d cross tunnel with small distance under the action of seismic loading, a shaking table model test with a similarity ratio of 1:50 was carried out. The experiment was designed and loaded with horizontal El-Centro seismic waves under 5 working conditions. The dynamic strain response of the tunnel was analyzed by collected test data, and the acceleration response of the intersecting and non-intersecting sections of the surrounding rock was compared and studied. Furthermore, the response spectrum theory was used to study the dynamic relationship between tunnel structure and ground motion. The test results showed that: the hoop and axial strain peaks of the upper-span tunnel are larger than those of the under-crossing tunnel. Owing to the influence of the upper-span tunnel and the compacting effect of surrounding rock, the impact of seismic waves on the under-crossing tunnel is weakened. The dynamic response of space crossing tunnel under seismic load has a certain " hysteresis ", and the seismic damage of upper-span tunnel occurs earlier and more serious. The acceleration amplification effect along the elevation direction of measuring points shows significant peak characteristics. Additionally, the acceleration response of the non-intersection is the strongest near the crown of the upper-span tunnel, while the intersection appears at the crown of the under-crossing tunnel. Furthermore, the amplitude of displacement response spectrum of each measuring point increases gradually with the increase of input seismic amplitude, and the predominant period also increases, that is, the predominant frequency decreases gradually. The response spectrum curves in the short period (0.5~1.5 s) under the action of low earthquakes (0.1g) have significant peak characteristics, while the response spectrum curves in the long period (3.0~5.0 s) under the action of strong earthquakes (0.6g) have obvious amplification effects along the elevation.
  • MAO Jihua1,2, NIE Zhulin2, WANG Dayang1, XU Wei3, OU Tong4, CHEN Wei2, WU Fuchegn2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 101-112.
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    The wind-induced vibration response of long-span cable roof structures is complicated. Currently, one of the research focus is the applicability of the traditional equivalent static wind loads to calculate the wind-induced vibration response of long-span cable roof structures. This research focuses on four types of typical long-span cable roof structures: the concave type (the single-layer saddle-shaped cable net) and the convex types (the spoke-type double-layer cable net, the cable dome, and the string-supported dome), and all of them are tested by wind tunnel tests. Based on these data, two load value calculation modes and calculation procedures are proposed for the node dynamic wind load (Mode 1) and the area group dynamic wind load (Mode 2) by the nearest neighbor interpolation method, and are compared to the traditional equivalent static wind loads (Mode 3). The wind-induced vibration responses of four types of the typical cable roofs are studied with three different load value modes under four unfavorable wind direction angles. The results show that the wind vibration responses of the cable roof structure calculated based on Mode 1 and Mode 2 are respectively higher than that of Mode 3. In addition, it is more accurate to calculate the value of the node wind load of Mode 1, which reflects the actual wind load of the roof structure and effectively represents the actual wind-induced response of the roof structure. Furthermore, under the influence of no adjacent venues on the upstream and downstream, the average and fluctuating wind-induced displacement response cloud patterns of the concave and the convex cable roofs are relatively consistent, but their response sizes vary. The wind-induced displacement of the concave roof shows the tendency of gradually decreasing from the middle to the periphery, while the wind-induced displacement of the convex roof tends to increase from the central area to the middle ring and then reduce to the periphery.
  • SHI Yannan1,2,3, QI Penglei1, WANG Yu1, WANG Yiying1,2, ZHANG Chongchong1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 113-121.
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    In view of the complex working environment of underground coal mine, the collected microseismic signals contain a large number of noise signals, which seriously affects the pickup, location and inversion of microseismic signals. In this paper, complementary set empirical mode decomposition (CEEMD) combined with singular value decomposition (SVD) and STA/LTA are used to reduce noise. The microseismic signals were decomposed by CEEMD to obtain the inherent modal component (IMF) of the signals. The noise-dominated IMF and signal-dominated IMF were determined according to the correlation coefficient, and the pseudo-components generated by CEEMD were removed by STA/LTA. The denoised signal is obtained by SVD decomposition of noise-dominated IMF and reconstruction of signal-dominated IMF and residual components.  The simulation results show that the proposed algorithm can save the computation time under the condition of small residual noise.  Compared with empirical mode decomposition (EMD), ensemble empirical mode decomposition (EEMD) and novel adaptive ensemble empirical mode decomposition (NAEEMD) denoising methods, the three evaluation indexes of SNR, energy percentage and standard deviation are calculated quantitatively, and the results show that the proposed method has better denoising effect.
  • LI Xianhang1, CHEN Guangxiong1, MEI Guiming2, HE Junhua1, LIU Dayi1, FENG Xiaohang1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 122-135.
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    A full-size finite element model of a pantograph-rigid catenary system was established, and the normal and tangential motions of the pantograph-rigid catenary system were dynamically coupled by sliding friction. Based on the theory of the friction-induced self-excited vibration causing corrugation, the effects of pantograph-rigid catenary system parameters on the contact wire corrugation were studied by using the complex eigenvalue method. The results show that when the friction coefficient μ≥0.15, the friction-induced self-excited vibration occurs at a frequency ƒ=818.01Hz, and this friction-induced self-excited vibration causes rigid contact wire corrugation. When the friction coefficient μ<0.15, the contact wire corrugation can be significantly reduced. When the normal contact force F≤110N or the span L=6m, the contact wire corrugation can be effectively alleviated. When the stiffness of the pantograph-head suspension torsion spring K=100N•m/rad, contact wire corrugation can be suppressed.
  • LI Rui1,2, FAN Yugang1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 127-135.
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    The check valve of high-pressure diaphragm pump is affected by load, friction, impact and other factors, and the vibration signal generated by operation is non-stationary and nonlinear. In order to extract the nonlinear dynamic characteristics of equipment from the vibration signal, multi-scale permutation entropy (MPE) is introduced into the fault diagnosis of check valve of high-pressure diaphragm pump.The multi-scale permutation entropy feature of vibration signal is extracted to establish the fault diagnosis model of structure optimization regularized extreme learning machine (SO-RELM). The model uses K-means to optimize the RELM structure and improve the accuracy and stability of model recognition. Firstly, adaptive complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN) is used to adaptively decompose the vibration signal of high-pressure diaphragm pump check valve into multiple intrinsic mode functions (IMF), taking the correlation coefficient as the index, the components with rich fault characteristic information are preferred; Then, the multi-scale permutation entropy of IMFs is calculated to extract the nonlinear dynamic characteristics of the signal; Finally, based on multi-scale permutation entropy, a fault diagnosis model based on SO-RELM is established.The experimental results show that CEEMDAN multi-scale permutation entropy can accurately characterize the nonlinear dynamic characteristics of the operation state of the check valve of the high-pressure diaphragm pump. The SO-RELM fault model based on CEEMDAN multi-scale permutation entropy can effectively identify the working condition type of the check valve of the high-pressure diaphragm pump, and the accuracy is 98.89%.
  • CUI Zhenglong, FEI Haichao, SUN Wanji, LI Zhengyuan
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 136-142.
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    In order to explore the influence of steel fiber content ( volume rate 0 %, 0.8 %, 1.5 % ) on the basic mechanical properties of C30 recycled coarse aggregate concrete ( mass fraction replacement rate 0 %, 100 % ), the damage evolution law of steel fiber recycled coarse aggregate concrete during axial compression was described by combining acoustic emission characteristic parameters and stress-strain curve. The test results show that through the analysis of acoustic emission damage location, impact count and energy count, the dynamic monitoring of the whole process of axial compression failure of steel fiber recycled coarse aggregate concrete from cumulative damage to micro-crack evolution and then to macro-crack propagation can be realized. The concentrated location of damage points in the loading process of recycled coarse aggregate concrete and ordinary concrete specimens with different steel fiber contents is consistent with the final failure location of the specimens. The concrete damage model based on acoustic emission cumulative impact count can be used to analyze the damage evolution law of steel fiber recycled coarse aggregate concrete.
  • LUO Hui, LI Tong, HUANG Qianghua, BO Ke, CHAI Sen, LI Xiang
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 143-149.
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    Through the step-up hydrostatic burst test of large-volume glass fiber wrapped composite cylinders, the acoustic emission technology was used to monitor the wrapped layer damage evolution behaviors during the step-up burst process and the acoustic emission signal response characteristics at different stages of boosting. The amplitude, count, cumulative count, and energy of acoustic emission signals in different stages were obtained. When the test pressure increased from 40 MPa to 50 MPa, the wrapped layer was damaged, the acoustic emission signal activity increases by about 90 times, and the fiber breaking signal strength was high, reached 1.0×108 aJ. On this basis, through the hydrostatic burst test of cylinders with different degrees of impact damage, the difference in acoustic emission response of cylinders with different damages in the 0-30 MPa stage was compared and analyzed. The test results show that the acoustic emission signal of the wrapped layer increased with the increase of the wrapped layer damage degree, and the signal activity and intensity increased. The signal activity of the wrapped layer of the critically damaged cylinder increased by 20 times, and the signal intensity reached 2.0×105 aJ. Therefore, during the hydrostatic test, the safely of impact damage of composite cylinder could be evaluated by compared the characteristics of the acoustic emission signal amplitude and count of the impact damage area and critical damage wrapped layer.
  • LIU Yumei1, WANG Mengyu1, ZHUANG Jiaojiao2, CHEN Rong1, YANG Jianyu3
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 150-159.
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    In order to ensure the smooth operation of High-speed Variable-gauge Train on different gauge lines, the secondary air spring and magnetorheological damper with adjustable damping wereadopted,and the damping parameters were adjusted by semi-active control method.Based on the fractional calculus theory, the sliding mode reference model of the fractional canopy damping control for a quarter vehicle was established, and the fuzzy RBF sliding mode semi-active control method was proposed.The fuzzy RBF sliding mode semi-active control method was applied to the semi-active control system of vertical air spring and transverse MR damper of variable gauge bogie.The whole vehicle combined simulation model of semi-active control forHigh-speed Variable-gauge Train suspension system was constructed, the running stability, motion stability and curve trafficability of variable gauge vehicles and the robustness of semi-active control strategy under different gauge lines were analyzed to verify the effectiveness of the whole vehicle semi-active control strategy.
  • HAN Feng1, WANG Chunmei2, KOU Xing3, WU Xiaoyu3, PEI Cuixiang3
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 160-165.
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    In order to improve the detecting ability of the laser ultrasonic testing technology, an enhanced laser ultrasonic testing method based on pulse compression is proposed for metal surface crack inspection. With using a space-modulated laser beam, a linear frequency modulation ultrasonic Rayleigh wave is generated. The signal-to-noise ratio and resolution of laser ultrasonic testing signal can be greatly improved by pulse compression of linear frequency modulation laser ultrasonic surface wave signal by matched filtering algorithm. A numerical simulation model of spatial modulated laser ultrasound is established, to study the excitation of chirp laser ultrasonic signals. Then, based on the chirp laser ultrasonic signal obtained by numerical simulation, a laser ultrasonic pulse compression signal processing method based on matched filter is developed. The enhancement of signal-to-noise ratio (SNR) of laser ultrasonic testing is investigated by simulating the effect of pulse compression under different defects and spatial modulation. The results show that the enhanced laser ultrasonic testing method based on pulse compression technique can suppress noise signal greatly, improve the ability of surface defect detection, solve the problem of low signal-to-noise ratio and poor sensitivity in laser ultrasound, it also can provide theoretical basis and experimental instruction for the further research of this method.
  • MA Liang1, FAN Jie3, LI Chenghao1, HAN Zhixuan1, WANG Jun2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 176-175.
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    A double coil magnetorheological damper (MR damper) based on squeeze mode was obtained by using the coupling design method of integrated magnetic circuit and component design. On the basis of the closed magnetic circuit, the initial structural parameters were obtained by considering the properties of magnetic field, magnetic circuit, structural characteristics of damper, their interaction and feedback to the magnetic circuit. The multi-objective optimization of key parameters was carried out by using Simulated Annealing Algorithm to optimize the comprehensive performance of the damper, and the design method of MR damper was concluded. By the multi-dimensional magnetic field measurement test-bed, the magnetic field of the oil film working face was measured, which verifies that the measured values of the double coil MR damper under different excitation currents are in good agreement with the simulation values. Finally, the optimized dual-coil MR damper was introduced into the rotor system, and the rotor experimental platform supported by the MR damper was built. The unbalanced response experiment of the rotor system supported by the MR damper was carried out. It is found that the MR damper with a suitable current can provide effective damping for the rotor system, which greatly suppresses the vibration amplitude of the rotor system near the critical speed; Under the action of excessive current, the stiffness effect of the MR damper plays a major role, which will limit the squeezing of the oil film in the clearance of MR damper, thereby weakening the damping effect of MR damper. This research provides certain guidance for the design of MR damper and has potential application value.
  • LI Zhixin, ZHENG Zhiwei, HUANG Xiuchang
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 176-182.
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    Piezoelectric composites are used to absorb structural vibration energy for damping and to apply voltage for actuation due to their superior mechanical-to-electrical energy conversion capability. In this paper, the design and optimization of the damping and actuation performance of a multilayer piezoelectric composite structure composed of carbon-glass-piezoelectric fibers are presented, and the corresponding structural lay-up recommendations and optimization results are given. The structure consists of a multilayer unidirectional hybrid fiber composite substrate and distributed piezoelectric patches, in which carbon, piezoelectric and glass fibers are laid symmetrically, and the piezoelectric patches are attached to the surface. Based on the Euler-Bernoulli beam theory and Hamilton's principle, the electromechanical coupling model of the piezoelectric composite structure dynamic characteristics is analyzed. By comparing the damping and actuation performance, the optimal lay-up sequence of the structure is obtained. The genetic algorithm (GA) is used to optimize the piezoelectric patches’ positions and the lay-up angle to improve the vibration damping and actuation performance, respectively. The results show that the outermost distributed piezoelectric patches have a significant damping effect and the inner piezoelectric layer has better actuation capability. Compared with the empirical arrangement, the damping performance of the first three modes optimized by the genetic algorithm is improved by 0.67 dB, 0.77 dB and 1.87 dB. For better actuation effect, the carbon and glass fiber angles are 90.0015° and 53.0652°.
  • TANG Ruoli, ZHANG Shangyu, WU Wenjun
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 183-189.
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    In industries that require extensive use of various types of pipelines such as ship transportation and petrochemical industry, structural health monitoring (SHM) of pipelines is of great significance for the safe and stable operation of industrial systems. In terms of pipeline crack grade identification based on ultrasonic guided wave, this paper constructs the finite element simulation model of the actual pipeline object, and synthesizes guided wave data closer to the actual detection by adding noise. Based on the finite element simulation sample database containing different pipeline crack grades, a pipeline crack grade recognition model based on multi-scale one-dimensional convolution neural network (MS-1DCNN) is proposed in this paper. The model realizes the direct use of the original waveform signal as the model input in an end-to-end manner, without the need for special design of signal noise reduction and feature extraction algorithm. The experimental results show that the model has higher accuracy than the traditional machine learning method in identifying pipeline crack grade in noise environment. In addition, this paper builds an experimental platform for crack identification based on physical pipelines, which further verifies the effectiveness of the proposed models and methods in pipeline structural health monitoring.
  • SUN Huahuai1, XU Jun2, CHEN Weizhen2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 190-199.
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    Due to the complex structure and many influencing factors, the initial finite element model of a cable-stayed bridge cannot accurately reflect the actual structure, and the mechanical properties of cable-stayed bridge continue to deteriorate in service. Therefore, establishing a numerical model reflecting the real state of a cable-stayed bridge is the key to track its time-varying mechanical properties. In this study, a method is proposed to track time-varying mechanical properties of an in-service cable-stayed bridges based on an adaptive model. Firstly, with the measured cable forces at the completion stage, multi-objective optimization method is adopted to update the finite element model of a cable-stayed bridge. Based on the updated finite element model, the step-by-step finite element method is used to numerically track time-varying mechanical properties of an in-service cable-stayed bridge with concrete shrinkage, creep and ambient temperature effects. The proposed method is used to numerically evaluate the time-varying mechanical properties of Haihe Bridge after one and two years of service. The actual mechanical properties of the bridge are inspected regularly. The results show that the relative differences between the numerical results and the measured cable forces after 1 and 2 years of service remain within ±10%. The maximum differences between the numerical results of girder deflections and the measured values are -0.025 m and -0.013 m, separately. Thus, the adaptive model can effectively track time-varying mechanical properties of in-service cable-stayed bridges. In the service stage, the deflection of the main span girder of the hybrid girder cable-stayed bridge gradually increases, and the changes of deflection in the side span girder was very small.
  • CHAI Xiaopeng1,2, JING Guoqiang1,2, WU Xiaobo1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 200-204.
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    In order to control the wind-induced vibration for hanger cables of long-span suspension bridges, a damping technical scheme based on multiple tuned mass dampers (MTMD) is proposed, and the parameters are optimized and designed through theoretical analysis. Study the actual wind-induced vibration responses for hanger cables of Nansha Bridge two main channel suspension bridges, analysis the frequencies and vibration characteristics, proposes the vibration control target. The cable-MTMD analysis model is established to optimize the parameters such as frequency distribution, damping ratio, installation position and modal participation coefficient of MTMD in multi-mode vibration control of hanger cable. The results show that, different from the optimization theory of single frequency control, the MTMD damping ratio for multi-mode control of hanger cables is increased to 10%, extend the frequency coverage of vibration control. By considering the modal participation coefficient,optimize four main frequencies: 13.5Hz and 18Hz are installed at a position ratio of 2.9%, and 6.5Hz and 9.5Hz are installed at a position ratio of 6.5%, realize the cable’s multi-mode (5~20Hz) wind-induced vibration control; for the different lengths cables with the similar cable force, type and controlled frequency ranges, the MTMD’s design parameters can be designed uniformly.
  • ZHAO Xinyang1, MEI Zhiyuan1, ZHU Yi1, DU Du2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 205-214.
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    In order to accurately predict the target strength of non-watertight structure with acoustic coating on the surface and pressure cylinder inside, a new parameter inversion method is constructed in this paper. Combining genetic algorithm with nonlinear programming, a double-layer elastic media layer inversion model is established using the layered media theory to replace the acoustic coating layer containing complex internal structure,taking into account the oblique incidence, multiple scattering,anastomosis effect and transverse wave velocity threshold.The inversion model and the original structure have basically the same reflection coefficient and transmission coefficient at all angles. Furthermore, A complex non-watertight structure with an acoustic overlay laid on the surface and a pressure-resistant cylinder inside is constructed by COMSOL Multiphysics , and the shell is an equivalent structure composed of two inverted materials, and calculate its acoustic scattering characteristics. The results show that in the case of monostatic,the target strength values of the original structure and the equivalent structure are basically the same, and the overall error of the research frequency band when incident in each direction is less than 1.5dB; In the case of 30 ° bistatic, the peak and trough trends of the target strength of the original structure and the equivalent structure at each frequency are the same, and the overall error of the research frequency band when incident in each direction is less than 2dB. In the middle and high frequency band, the target intensity directivity of the original structure and the equivalent structure is better; In the middle and low frequency bands, the target intensity directivity of the original structure and the equivalent structure is basically the same, but there are differences in amplitude; Overall, in the range of -30 ° ~ 30 °, except for a few frequencies, the original structure is basically consistent with the target strength of the equivalent structure.
  • PAN Chenghao1, CHEN Guoping1,2, HE Huan1,2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 215-222.
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    A cross-section interpolation beam model was proposed to solve the dynamic and static response of the beam under nonuniform thermal load. It solved the problem that the traditional beam theory cannot deal with the beam subjected to nonuniform temperature field. Firstly, the Lagrange interpolation function was used to interpolate the section and axial of the beam element to construct the displacement field of the beam. Then, the displacement field was substituted into the thermoelastic dynamic equation, and the element strain and stress were obtained. According to the principle of virtual work, the element stiffness matrix, mass matrix and equivalent node load array were derived, and the thermal stress was solved. Finally, the element stiffness matrix was updated by the transverse shear force of thermal stress to calculate the vibration characteristics of the beam under thermal load. The calculation results showed that the results obtained by the method in this paper are consistent with the results of the solid element model, and it is easier to deal with the slender structure under non-uniform thermal load, and can well reflect the shape, load and response results of the cross section. 
  • LIU Xuqi, HE Zhenxing, YANG Lirong
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 223-232.
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    High-speed railway wheel-rail dynamic interaction is complex in curve section, the adaptability of intelligent recognition algorithm in curve section is the premise of realizing continuous recognition and tracking wheel flat along the whole line. Considering the random characteristics of wheel flat signal of high-speed railway, a method of wheel flat recognition based on variational mode decomposition (VMD) was proposed. Considering the influence of different curve sections and rail sides, the random response of wheel-rail force obtained by dynamic calculation was decomposed by variational mode decomposition and the signal was reconstructed. The impact frequency and corresponding length of wheel flat are identified by envelope spectrum characteristics. The results show that the envelope spectrum of normal wheel is obviously different from the wheel with flat. In envelope spectrum, the frequency double peak above 10 mm wheel flat is obvious; The peak frequency characteristics of frequency doubling are consistent with the impact frequency of flat corresponding to train speed; The mean value of the amplitude corresponding to the first four orders of frequency multiplication is linear with the length of flat, which can be used to directly distinguish the length of flat. After correcting the length of flat recognized by the curve outer rail side, the continuous recognition and tracking of the wheel flat can be realized.
  • QIN Weifeng, YANG Xiaoyue, SHI Junyang, XIE Jiming
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 233-244.
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    A comparison study is conducted on aerodynamic characteristics and wind resistance of twin-tower buildings with two configurations, i.e., side-by-side and corner-to-corner, based on wind tunnel testing and aftermath analysis. The purpose of the study is to provide technical references to the optimization design of supertall twin buildings. The results indicate that the performance of the twin-tower buildings to wind effects depends on many factors, including the spacing between the two buildings, the structural dynamic properties, design wind speed, etc. In a lower reduced wind speed, the wind responses of the twin-tower buildings with these two configurations are similar to each other. However, when the reduced wind speed exceeds 7, the twin-tower buildings become quite sensitive to the spacing between the two buildings, and corresponding performance of these two configurations appears very different from each other. At relative spacing of 0.5 or narrower, the corner-to-corner configuration can cause severe wake buffeting, so the side-by-side configuration shows better performance for wind effects. However, as the spacing increases, the wake buffeting in the corner-to-corner configuration becomes less significant. Meanwhile, the corner-to-corner configuration starts to show a more sustainable benefit than the side-by-side configuration in suppressing vortex shedding by aerodynamic interference, which results in a much lower response in the across-wind dynamic response. At a relative spacing of 2, the wind-induced overturning moment of the corner-to-corner configuration is only about 60% of that of the side-by-side configuration.
  • SHAN Jiangbei1, LIU Xiaoling1, WANG Bing2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 245-252.
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    To adapt to the development of prefabricated composite beam, a new stainless steel removable bolt connector was developed, and the mechanical performance degradation law under fatigue load was studied. First of all, Through the literature and market research, fully considering of the advantages and disadvantages of the existing bolts, a new stainless steel removable bolt connector for prefabricated composite beam was designed and produced; Secondly, six sets of push-out tests with new bolt connections were conducted for static and fatigue tests. Comparing the failure mode of specimens after static load and fatigue load with different cycle times, the residual bearing capacity, residual slip amount, shear stiffness and ductility coefficient of the new bolt connections during fatigue load were analyzed; Finally, based on the fatigue accumulation damage theory and the material residual strength model, the damage degree of the new bolt connector during fatigue loading was determined, the calculation model of bolt bearing capacity was established. The results show that the new bolt connector has different deformation and failure characteristics of section under static and fatigue loads; the mechanical properties of the new bolt connector show irreversible degradation after fatigue load. In this test, after 2.7 million fatigue loadings, the residual bearing capacity of specimens deteriorates by 12.1%, ductility coefficient deteriorates by 67.6%, shear rigidity deteriorates by 12.9%, and the degradation is obvious. The calculation result of the proposed residual bearing capacity of bolt connectors shows good agreement with the test value.
  • ZHANG Weitao1, CUI Dan1, LIU Lu1, HUANG Ju2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 253-262.
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    Aiming at the problem that the fault diagnosis performance of existing convolutional neural network(CNN)declines sharply due to the wide range of aero-engine rotate speed, fault diagnosis method based on wavelet packet reconstruction imaging and deep and shallow feature fusion classification network is proposed. Firstly, wavelet packet transform(WPT)is used to extract the effective components from the vibration signal and eliminate the interference components. Then, the reconstructed vibration signal is imaging by short-time Fourier transform(STFT), and the time-frequency spectrum samples are obtained. Finally, the problem of fault classification under time-varying rotating speed, the proposed network is established by jump connection to complete fault classification. The effectiveness of the proposed method is verified by the multi-channel vibration signals collected by bearing test machine, the results show that the proposed method still has higher recognition accuracy when the training set and test set samples have different speeds.
  • YIN Xingchao, GUO Yu, LI Zhentao, HUA Jianxiang
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 263-268.
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    Because the time-varying transmission path and the vibration sensor are limited by the lower limit of measured frequency, it is difficult to detect the solar wheel fault based on conventional vibration signals under the condition of low rotational speed. In this paper, combining the advantages of encoder signal, a sun wheel fault detection method based on narrow band demodulation technology of encoder signal is proposed. Firstly, the Angle signal of raster encoder is collected by T method, then instantaneous angular velocity (IAS) signal is obtained by forward difference method, then the asynchronous interference component is suppressed by Angle domain synchronous averaging, and finally the fault detection of solar wheel is realized by narrowband demodulation. Meanwhile, a kurtosis based demodulation frequency band selection strategy and a fault feature enhancement method based on phase change rate of phase demodulation function are proposed. Experimental results show that IAS signal can effectively overcome the shortcomings of conventional vibration detection methods, and the proposed method can effectively realize the detection of solar wheel faults.
  • YU Chuanqiang1, SHU Hongbin1, LIU Zhihao1, CHEN Jianwei1, GAO Yang2
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 269-278.
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    Multi-axle heavy-duty special vehicles have the characteristics of heavy load, high center of mass, and fast speed, and there is the possibility of handling instability under high maneuvering conditions. The center of mass slip angle and the yaw rate are the key criteria for measuring the stability of the vehicle. If directly measured by the on-board sensor, there are problems such as difficulty in measurement, high cost, and long-term error. Therefore, a study on the state estimation of five-axle heavy vehicles has been carried out.. Research. First, a 13-degree-of-freedom dynamic model of a five-axle special vehicle was built based on Matlab/Simulink, and a real-vehicle experiment was carried out using the driving condition monitoring system to verify the accuracy of the 13-degree-of-freedom model, providing a theoretical basis for the estimation model and a verification simulation platform. Then a nonlinear three-degree-of-freedom vehicle model is established. Based on the unscented Kalman filter algorithm, state estimators for yaw rate, center of mass slip angle, and longitudinal velocity are designed. Finally, the 13-degree-of-freedom model is used as the simulation platform to verify the angular step input, pulse input and sinusoidal input conditions. The results show that the state estimator based on the nonlinear three-degree-of-freedom vehicle model can realize the dynamic estimation of the parameters of longitudinal velocity, yaw rate and side slip angle of centroid.
  • CHEN Shuhai1, 3, GUO Anfeng2, WU Shaoqing2, FEI Qingguo1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 279-286.
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    A new method for the identification of dynamic load between satellite and rocket by using BP neural network is proposed. At first, a high-fidelity dynamic model of the satellite structure is built and the data base including both the structural response of the satellite and the base excitation acceleration at the interface between satellite and rocket can be obtained via numerical analysis or ground experiments; Secondly, the relationship between the structural response of the satellite and the excitation acceleration at the interface between satellite and rocket can be trained by using BP neural network, based on which the base excitation acceleration at the interface between satellite and rocket can be identified from measured structural response of the satellite; Finally, by applying the identified base excitation acceleration on the high-fidelity dynamic model of the satellite structure, the dynamic load at the interface between satellite and rocket can be calculated. Numerical simulation and vibration test are conducted to verify the effectiveness of the proposed method, which can provide strong support on the prediction of vibration load environment of the satellite structure under service condition.
  • DONG Qian1,3, ZHANG Xianmin1,2, BAO Yiting1, CHENG Shaofeng1, ZHANG Yuhui1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 287-294.
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    A four-degree-of-freedom model of the aircraft main landing gears was established to accurately calculate the aircraft dynamic loads which change randomly with time and positions during the taxiing. The coupling between aircraft and pavement was analyzed. The random dynamic load of each main landing gear of B737-800 was obtained considering the influence of pavement roughness and aircraft lift by finite element simulation technology. The power spectral density of aircraft dynamic load was obtained by the Welch method, and the rule of load energy distribution in frequency domain was explored. The research results show that when the taxiing speed remains unchanged and the International Roughness Index are 1.56, 3.12, and 4.68, the peak dynamic load on each main landing gear of the B737-800 can increase by 7%. When the International Roughness Index remains unchanged and the aircraft taxiing speed increases from 10m/s to 40m/s, the dynamic load tends to decrease under the influence of aircraft lift. The increase of taxiing speed, the increase of the suspension stiffness and the increase of non-suspension stiffness all lead to the increase of the frequency of aircraft random dynamic load. With the decrease of the pavement roughness, the frequency of aircraft dynamic load remains unchanged, and only the peak value of the power spectral density increases. With the increase of the aircraft suspension damping, the peak value of the power spectral density of the dynamic load decreases obviously, but the frequency remains unchanged. However, the damping the non-suspended part effect extremely tiny on the power spectral density of random dynamic loads.
  • YU Jinshan1, TAO Jianguo1, WANG Guoxing2, LI Xiao3, WANG Haowei3
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 295-304.
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    Aiming at the on-orbit assembly task of large space structures, a scheme of cable-driven parallel mechanism(CDPM) is proposed, and its vibration characteristics are studied. Firstly, the stiffness matrix of the mechanism is deduced based on differential transformation. The vibration equation is established on this basis, and the analytical expressions of each order mode are obtained. Secondly, the influence of the pose of the moving platform and the level of cable tension on the vibration characteristics of the mechanism is analyzed through theoretical calculation, and the vibration law of the mechanism under different working conditions is studied through simulation. Finally, a scaled prototype of the CDPM is built and the vibration characteristics experiment of the mechanism is carried out, which further verifies the correctness of the vibration model and the validity of the simulation results. The results show that when the moving platform is at the center position, the modes of each order are decoupled, and the vibrations in different directions do not affect each other. At the edge position, the modes of each order have strong coupling, and the disturbance force in one direction will cause vibration in multiple directions. The vibration frequency is mainly the first and second order natural frequencies. The research results have guiding significance for the vibration control of CDPM.
  • JU Zegang1, WU Fei2, ZHAO Jiang1, HU Man1, GAO Mingyuan1, HAO Yaodong3, CHEN Daliang3
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 305-312.
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    There is a coupling problem between high-speed grazing flow field and high sound intensity sound field on the acoustic liner surface of turbofan aero engine, and the sound absorption mechanism and regulation mechanism are complex. The effective absorption of low-frequency broadband noise under the condition of high grazing velocity and high sound intensity is very challenging. In this paper, a theoretical method of acoustic impedance considering high grazing velocity, high sound intensity and complex capacitive reactance correction is proposed, and a gradient acoustic impedance controlled sound absorbing metamaterial is designed. The interaction mechanism between sound wave and structure and the regulation law of sound wave are deeply analyzed from three dimensions: theoretical analytical calculation, finite element numerical modeling and experimental verification. The results show that the gradient impedance sound absorbing metamaterial can effectively improve the sound absorption efficiency and avoid the disadvantage of the narrow sound absorption band of the traditional acoustic liner. Under the grazing velocity of 0m/s, 30m/s, 60m/s, 98m/s and 130dB background noise, the gradient impedance sound-absorbing metamaterial proposed in this paper has a good sound-absorbing effect in the range of 500Hz-3000Hz. The metamaterial has a simple structure and still has deep sub-wave and broadband sound absorption characteristics under the complex boundary conditions of high grazing velocity and high sound intensity.
  • JIANG Dong1, QIAN Hui1, ZHU Rui2, WU Yimeng1, HU Jiamiao1
    JOURNAL OF VIBRATION AND SHOCK. 2023, 42(5): 313-322.
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    It is difficult to obtain the modes of large flexible structures by traditional testing methods due to the low stiffness and large size. A method for modal identification of large flexible structures based on initial displacement excitation is proposed. Firstly, it is theoretically proved that the structural response under monolithic displacement excitation can be approximated as an impulse response signal. Then, an integral initial displacement excitation is applied to a large flexible structure to obtain the overall vibration response of the structure. Finally, the low frequency global modes of large flexible structures are identified based on the feature system implementation algorithm. The feasibility of structural modal parameter identification under monolithic displacement excitation is verified by taking a truss with a length of 30 m as the research object, and the identification accuracy of the structure under white noise condition is discussed. The modal tests of concentrated mass flexible beams with theoretical solutions are carried out to verify the proposed method. The results show that the low frequency modal parameters of the flexible structure can be effectively identified by applying integral excitation.