15 August 2021, Volume 40 Issue 15
    

  • Select all
    |
  • ZHANG Zixiang, WANG Jianyao, WANG Hongdong, YI Hong
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 1-10.
    Abstract ( 379 ) Download PDF ( 171 )   Knowledge map   Save
    Liquid filled pipeline is one of the main radiated noise sources and self-noise sources of ships, it seriously affects the fighting capacity of ships. It is necessary to perform vibration modal tests and prediction of liquid filled pipeline with elastic constraints. Here, modal tests of pipeline without liquid filled were conducted. Under the condition of unknown constraints, the multi-objective genetic algorithm NSGA-Ⅱ was used to modify elastic constraints, and the finite element (FE) method based on bidirectional fluid-structure coupling was used to predict wet modal vibration characteristics of liquid filled pipeline. It was shown that the average error of natural frequencies between dry modal FE simulation results and test ones and that between wet modal FE simulation results and test ones were 3.06% and 2.47%, respectively and their maximum errors were within ranges of 0-6.19% and 0-5.30%, respectively; modal shape of each wet mode is basically same as that of dry mode, they agree well with each other; natural frequencies of wet modes were lower than those of dry modes, and each order frequency drift proportion is basically the same. The results showed that the modified results for constraints of pipeline dry modes with the proposed method can be applied in its wet modes FE analysis to obtain good simulation accuracy; the multi-objective optimization method used can avoid difficulties of weight choosing and unclear physical meaning of the objective function, and flexibly select the modified results according to the actual needs and preferences; reference and suggestions are provided for related works.
  • LIU Nan, YI Jianing, WANG Dong, HOU Liangxue, YANG Ximing
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 11-17.
    Abstract ( 313 ) Download PDF ( 97 )   Knowledge map   Save
    In order to improve efficiency and safety of transonic flutter tests in a temporary impulse wind tunnel, an efficient flutter prediction method was established based on the auto-regressive moving average (ARMA) system identification method. Based on compensation decoupling and expert PID, a constant Mach number continuous variable pressure flow field control technology was developed for the FL-60 wind tunnel. Firstly, the ARMA system identification method was verified with the international standard model AGARD445.6 wing, and it was shown that the difference between the calculation results for flutter velocity pressure and frequency and those with the CFD/CSD coupled method is not more than 4%. Then, the flow field of the FL-60 wind tunnel was debugged to verify the continuous variable pressure flow field control of the FL-60 wind tunnel, and it was shown that velocity pressure variation has high linearity and the control accuracy of Mach number is ± 0.003. Finally, flutter tests of the flat tail model with continuous varying velocity pressure were conducted, and the results showed that the difference between flutter velocity pressures obtained by step tests and continuous varying velocity pressure tests is less than 2%; the flutter boundary calculation results agree well with those of wind tunnel tests; the proposed numerical method can provide a good guidance for test arrangement before test.
  • SONG Qiang, SUN Danting, ZHANG Wei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 18-25.
    Abstract ( 259 ) Download PDF ( )   Knowledge map   Save
    In a two-gear pair AMT of pure electric vehicle, nonlinear vibration of helical gear transmission system can cause vibration and noise of the transmission. Here, in order to study nonlinear vibration characteristics of the two-gear pair AMT helical gear system, considering time-varying meshing stiffness, tooth side clearance, static transmission error and bearing support stiffness of the system, the bending-torsion-axis coupled dynamic model of the system was established to analyze bifurcation diagram and its phase diagram features of the coupled vibration characteristics. The results showed that when the transmission is operating with the first gear pair, the meshing frequency increases with increase in speed, and the system has periodic motion and chaos; when the load-bearing gear pair is in a single-period motion, torsional vibration intensity of the gear pair without load-bearing increases with increase in speed; appropriately increasing gear pair mesh damping ratio and meshing stiffness is helpful to reduce the amplitude of the maximum torsional vibration point of the load-bearing gear pair; the study results can provide a technical support for structural design, dynamic analysis and gearshift application of two-gear pair AMT of pure electric vehicle.
  • YUN Xialun, YUAN Shijue, MEI Xuesong, JIANG Gedong, WANG Chen
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 26-33.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Liquid injection on-line dynamic balancing is one of the main on-line balancing methods of ultra-high speed motorized spindle. Here, in order to solve the problem of balance precision loss caused by low design precision of traditional liquid injection on-line balancing terminal cavity, considering effects of complex oil-gas flow state in balancing terminal cavity under high-speed rotating state, four cavity analysis models with different cross-section shapes were established. The fluid simulation analysis software FLUENT was used to realize 3-D numerical simulation for fluid in balancing terminal cavity based on VOF method. Turbulent flow, liquid distribution and combined pressure of cavity outer wall for liquids with different mass densities in the 4 cavities under the condition of different rotating speeds were studied. The study showed that the 90F shape cavity is the best cross-section shape cavity. The finite element analysis model for the outer wall of balancing terminal cavity was established to optimize parameters of balancing terminal cavity under extreme conditions of the highest rotating speed and cavity fully filled by liquid. The 3-D printing technology was used to manufacture the optimized balancing terminal, and online dynamic balancing tests were conducted on an ultra-high speed milling motorized spindle test platform. The test results showed that the terminal unbalance amplitude under the operating frequency drops by more than 90% before and after balancing to effectively improve balancing performance.
  • WU Jingran, LIU Jianhua, CUI Ran
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 34-40.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, aiming at the problem of deep unsupervised bearing fault diagnosis network only aligning global distribution without considering the fine-grained information of each category in source domain and target domain, a sub-domain adaptive unsupervised end-to-end bearing fault diagnosis network was proposed. Firstly, 1-D convolutional neural network was used to do feature extraction, and multi-classification functions were used to construct classifiers. Then, by minimizing the local maximum average difference and loss function of classifier, the distribution of related sub-domains was aligned. Finally, the effectiveness of the proposed method was verified with the bearing fault data set of Jiangnan University. The results showed that the recognition accuracy of the proposed method is obviously higher than those of the other 5 popular domain adaptive fault diagnosis methods when the target domain data is unlabeled. The t-distributed random neighbor embedding results showed that the proposed method can effectively align category information of source domain and target domain; the feasibility and effectiveness of the proposed method are verified.
  • WANG Yao, LI Zhanlong, LIU Qi, LIAN Jinyi, WANG Jianmei, QIN Yuan
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 41-47.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Due to low speed and heavy load of engineering vehicles, drivers and passengers are often exposed to vibrations with low frequency and large amplitude to cause low working efficiency and even serious vibration occupational diseases. The quasi-zero stiffness isolation system has characteristics of high static and low dynamic stiffness, it can effectively filter low-frequency vibration energy. A contact mechanism with negative stiffness can bring friction loss and other problems to cause the instability of mechanical morphology of negative stiffness mechanism. Now, a quasi-zero stiffness vibration isolation system is developed based on the parallel connection of non-contact negative stiffness (NCNS) mechanism and positive stiffness mechanism of pneumatic artificial muscle (PAM). Here, in order to find out the mechanism of stiffness behavior of the system, taking a multi-magnetic ring negative stiffness mechanism as the study object, the analytical model of its negative stiffness was established based on Biot-Savart’s law and Ampere’s law. The stiffness behavior characteristics of the mechanism under different parameters of magnetizing intensity, geometric parameters and magnetic field intensity were analyzed, and the verification tests were conducted. The results showed that axial magnetizing can obtain significant negative stiffness characteristics compared with radial magnetizing; increasing magnetic ring’s outer diameter, thickness and magnetic field intensity can improve the load-bearing capacity of the mechanism, but can’t change its negative stiffness range; increasing spacing between upper and lower magnetic rings can expand its negative stiffness range, but can’t change its load-bearing capacity; the correction determination coefficient between the calculation model and test results is 0.999 75, the calculation model meets accuracy requirements; the study results can provide a theoretical basis for further modeling, optimizing parameters and engineering application of quasi-zero stiffness vibration isolation systems.

     

  • TONG Junhui, PENG Jian, FU Xiang, SUN Hongxin
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 48-53.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on Euler-Bernoulli beam theory and time-delay feedback control strategy, the wonlinear vibration control equation of a tension leg in submerged floating tunnel under parametric excitation was established. Using Galerkin method and linear stability analysis, stability boundary conditions of the control system under time-delay action were obtained. Effects of different control parameters on the tension leg’s vibration response were analyzed through numerical calculation. The results showed that the reasonable time-delay value and gain value can greatly reduce vibration responses of the tension leg in underwater suspension tunnel, and improve its structural stability.
  • LI Chen, CHEN Guoyi, FANG Bo, ZANG Jian, ZHANG Yewei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 54-64.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, a new vibration control method for lever-type parallel nonlinear energy trap was proposed. Firstly, the amplitude-frequency response curve of the system was obtained based on the harmonic balance method and pseudo-arc length extension method. Secondly, Effects of mass, nonlinear stiffness and suspension position of the trap on the amplitude-frequency response of the system were analyzed. Finally, vibration absorption performances of the lever-type parallel nonlinear energy trap and the lever-type single nonlinear energy trap were compared after the isolated ring resonance response disappears. The simulation results showed that the vibration absorption performance of lever-type parallel nonlinear energy trap is better than that of lever-type single nonlinear energy trap under the condition of the same added mass.
  • TANG Feng, WANG Yong, DING Hu, CHEN Liqun
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 65-72.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The 3-element parallel passive inerter-based vibration isolator based on “inerter-spring-damping” can further broaden vibration isolation frequency band of traditional linear isolator, but its high-frequency vibration isolation performance deteriorates significantly. Here, a semi-active inerter-based vibration isolator based on the skyhook-inertance control was proposed to improve its high-frequency vibration isolation performance. The skyhook-inertance control strategy used the absolute-relative acceleration switch control to switch the inertance of the semi-active inerter between its maximum and minimum values, and approximately simulate the mechanical property of the ideal skyhook inerter. Dynamic characteristics of the semi-active inerter-based vibration isolator under base harmonic displacement excitation were studied. The average method was used to solve the approximate analytical solution to the system, and it was verified using the numerical solution. The results showed that compared with the passive inerter-based vibration isolator, the semi-active inerter-based vibration isolator has lower absolute displacement peak value, lower transmissibility peak value and wider vibration isolation frequency band; the latter’s high frequency absolute displacement transmissibility drops obviously, it has a significant advantage over the former.
  • ZHOU Xin,QI Shemiao,LIU Heng
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 73-78.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, aiming at a thrust sliding bearing of a rolling bearing testing machine subjected to transient impact load, the dynamic model for the thrust bearing-rotor system and the simplified bearing pedestal structural deformation model were established. Reynolds equation for thrust bearing oil film was solved with the finite element method, the axial dynamic equation of the rotating shaft was solved using Euler integral method, and the structural deformation of bearing pedestal was solved with ANSYS simulation. Through the combined solving, variations of the thrust bearing’s oil film resultant force, minimum oil film thickness and flow rate with time varying in impact process were obtained. Impact responses of the thrust bearing considering and not considering structural deformation of bearing pedestal were compared. The results showed that effects of bearing pedestal elastic deformation on oil film resultant force and minimum oil film thickness can’t be ignored; without considering structural deformation, response speeds of oil film resultant force and minimum oil film thickness are much faster, and their response time decreases by about 22%; elastic deformation delays response process, it acts as a buffer and shortens the time required to reach the system’s steady state; when elastic deformation is considered or not, the maximum value of oil film resultant force and the minimum value of the minimum oil film thickness are basically the same; appropriate structural stiffness of bearing pedestal can improve the anti-impact ability of thrust bearing; the structural stiffness should not be less than a certain critical value, too small structural stiffness may cause the minimum oil film thickness of a certain tile to be very small and hard to bear large transient impact load; too large structural stiffness may cause bearing pedestal structure to be complex without buffering effect, and some connectors to fail too early.
  • JIANG Peibin, LING Liang, DING Xin, WANG Kaiyun, ZHAI Wanming
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 79-89.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With lightweight design of high-speed train, flexible vibration of vehicle body becomes more and more significant in running process. When the excitation frequency of track geometric irregularity with a specific wavelength is close to natural vibration frequencies of the vehicle system, the resonance between the vehicle system and the irregularity excitation can happen to affect the train operation safety and riding comfort. Here, to study the sensitive wavelength of high-speed railway track geometric irregularity, based on the vehicle-track coupled dynamics theory, a high-speed train -track coupled dynamic model considering flexible vibration of car body was established, and effects of wavelength variation of different types of track irregularity on dynamic performance of high-speed train were systematically studied. Then, the most unfavorable wavelength and sensitive wavelength range of different types of track geometric irregularity under different operating speeds were analyzed. The results showed that flexible vibration of car body significantly affects sensitive wavelength of track geometric irregularity of high-speed railway; the most unfavorable wavelength and sensitive wavelength range of different types of track geometric irregularity are different under different operating speeds; there are 3 significant wave bands of sensitive wavelength of track geometric irregularity of high-speed railway, the sensitive wavelength within short wave range of 3-10 m is mainly related to flexible modes of car body, the sensitive wavelength within medium wave range of 10-60 m is mainly related to rigid body modes of bogie, and the sensitive wavelength within long wave range of 60-140 m is mainly related to rigid modes of car body.
  • CHEN Ming HUANG Haijin, WANG Duoyin, L Senpeng, CHEN Yanji
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 90-97.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, to study effects of a closure plate on flow characteristics of impinging jet in a long straight circular pipe, the particle image velocimetry (PIV) tests were conducted to measure the flow field under different Reynolds number of 5 084-13 926 and impingement distance H/D of 2-6. Motion law of recirculation zone, change of potential flow core length, entrainment characteristics before jet impingement, wall jet expansion rate and velocity attenuation index were statistically analyzed. The test results showed that effect laws of Reynolds number and impingement distance on motion characteristics of recirculation zone are consistent with those of a semi-closed orifice plate impinging jet; flow characteristics before impingement reveal that effects of impingement distance is larger than those of Reynolds number on length of potential flow core and expansion rate of entrainment coefficient, length of potential flow core and expansion rate of entrainment coefficient increase with increase in impingement distance; flow characteristics of wall jet region reveal that expansion rate decreases with increase in Reynolds number, attenuation index increases with increase in Reynolds number when impingement distance is smaller (H/d=2), and then effects of Reynolds number on attenuation index gradually decrease with increase in impingement distance; compared with free impinging jet, existence of closure plate makes velocity attenuation of wall jet zone speed up, but its effects on expansion rate of wall jet zone are not significant, this result is significantly different from the existing study results about effects of closure plate on flow characteristics of orifice plate impinging jet.
  • YAN Guiyun, HUANG Guanhua, TENG Jun, ZHENG Lianqiong, XUE Panrong
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 92-106.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, in order to solve problems of insufficient aseismic capacity and difficult to repair after earthquake damage of prefabricated frame joints and connections, a new type of prefabricated energy dissipation joint connection was proposed. Low-cycle repeated loading tests were conducted for its key energy dissipation component called the replaceable weakened restrained steel-plate damper to investigate its hysteretic performances of load-bearing capacity, energy dissipation capacity, stiffness degradation and ductility, reveal its failure mechanism, and analyze effects of slot-opened weakening form, weakening length, steel plate thickness and gap between restraint sleeve and weakened steel plate on mechanical properties of the damper. The results showed that the replaceable weakened restrained steel plate damper cracks or breaks at the position of weakened section to realize controllable plastic energy dissipation and damper failure mode, and have good dual-function of load-bearing and energy dissipation; under the same parameters, load-bearing capacity, energy dissipation capacity and ductility of dog bone weakened restrained steel plate damper are better than those of vertical slot-opened weakened restrained steel plate damper; weakening length has a larger effect on ductility and lateral buckling performance of steel plate, steel plate thickness has a larger effect on load-bearing capacity and stiffness degradation performance; when gap between restraint sleeve and steel plate is larger, restraint sleeve can’t have effective action to cause the compression buckling of weakened steel plate.
  • CHEN Peng, ZHAO Shaomei CHEN Qin, XIE Zhijun, CHEN Xiaohui, TU Yaqing
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 107-113.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, in order to suppress effects of negative frequency spectrum leakage and mutual leakage among positive frequency spectra in multi-frequency real signals on frequency estimation, a frequency estimation algorithm based on spectrum leakage correction was proposed. Firstly, FFT method was used to preprocess a sampled signal, and obtain the spectrum index of various components, and then the signal spectrum was interpolated and analyzed to construct spectrum interpolations of all negative frequencies and positive frequencies not to be estimated. Secondly, constructed spectrum interpolations were subtracted from signal spectrum interpolations using the subtraction strategy to obtain spectrum interpolations without spectrum leakage for positive frequencies to be estimated, and then the spectrum offset estimation value of each component was obtained by analyzing generated spectrum interpolations. Finally, accurate estimated values of frequency, amplitude and initial phase of each component were obtained with iterative calculation. The simulation results under different frequency intervals and different SNRs showed that the proposed algorithm has good frequency estimation performance, it can effectively suppress effects of spectrum leakage, improve frequency estimation accuracy of multi-frequency real signals, and make the mean square error of frequency estimation value closer to Cramer-Rao low Bound; ranging tests are conducted on LFMCW radar test platform to verify the practical application effect of the proposed algorithm.
  • HUI Zhuo,QIN Weihong,XU Jianwu, ZHANG Pu, ZHANG Tongqing, XIE Peng, ZHANG Runlei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 114-122.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, in order to study progressive collapse path and failure mode of Geiger type carbon fiber cable dome structure, based on the alternate path method, the equivalent load instantaneous unloading method was used to simulate removal of initial failure components. The nonlinear dynamic numerical analysis was performed for the progressive collapse of a cable dome structure with a rise-span ratio of 0.1. The concepts of structural importance matrix and component importance coefficient were proposed, and then the collapse control equation was established. According to the collapse control equation, components were divided into key component, important one and general one. These three types of members were corresponding to 3 collapse results of whole structure progressive collapse, local progressive collapse and non-progressive collapse after removal of the component studied. Through analyzing parameters, the results showed that the components greatly affecting collapse results are inner ring cable, inner circle compression bar and middle circle one. Finally, design suggestions for Geiger type carbon fiber cable dome structure to improve its anti-progressive collapse performance were proposed.
  • XING Zhaoyang, SHEN Yongjun, XING Haijun, LI Xianghong
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 123-128.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Introducing negative stiffness into vibration control system can effectively suppress its resonance amplitude, but due to characteristics of negative stiffness, the system’s response in low frequency range can be amplified. Here, in order to improve this situation, the control strategy based on frequency identification was applied in the negative stiffness dynamic vibration absorber, and the short-time Fourier transform was used to do the time-frequency analysis for external excitation signal, track variation of its frequency versus time, and change negative stiffness of the system accordingly. Compared with the existing models under harmonic excitation and non-stationary excitation, it was shown that the proposed model has better low-frequency vibration reduction performance and can attenuate system vibration in the whole frequency domain.
  • CHEN Xudong, WANG Jiajia, TIAN Huaxuan
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 129-136.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    More and more waste tires bring serious environmental problems. Taking waste tire rubber particles as concrete aggregate can reduce pollution and the use of natural aggregate. Here, static bending-tensile tests and fatigue bending-tensile tests under different loadings were conducted for rubber self-compacting concrete beams using the hydraulic closed loop servo material testing machine MTS322. The fracture behavior of rubber self-compacting concrete beams under 3-point bending was studied systematically, and their fatigue failure laws under different loading stress levels and stress ratios were discussed to obtain the mathematical relationship between the ratio of stress field strength factor to fracture toughness and the logarithm of fatigue times. The fatigue damage prediction model of rubber self-compacting concrete was established. In test process, the acoustic emission (AE) technique was used to measure AE signals inside rubber self-compacting concrete beam under cyclic load in real time. The characteristics of crack development in rubber self-compacting concrete beam under different loading stress levels and stress ratios were compared. It was shown that the growth of inner cracks of rubber self-compacting concrete beam is divided into three stages; the lower the loading stress level, the more serious the fatigue damage degree inside rubber self-compacting concrete beam.
  • HAN Shijie, WANG Changhong
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 137-145.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, to control vertical vibration and rocking effect of nuclear power plant under earthquake, it was necessary to explore adopting vertical isolation technologyfor CAP1400 nuclear power plant based on its horizontal isolation study. Combined with structural parameters of the inclined rotating type3-D isolation bearing and CAP1400 nuclear power plant, a theoretical model of vertical isolation for CAP1400 nuclear power plant was proposed to calculate relation curve among vertical vibration, rocking effect and stiffness of isolation bearing. Dynamic analysis was used to obtainthe optimal setting number and spatial locations of isolation bearings. Then, the 3-D numerical model of CAP1400 nuclear power plant was established by using the large-scale structural finite element software ANSYS for verification. It was shown that the calculated vertical vibration acceleration, displacement and rocking effect of the nuclear power plant structure can satisfy the predetermined targets;thecalculation method explored here can be applied in vertical isolation design of nuclear power plant structure as a reference.
  • JIN Conghe, QIAN Yongjiu, XU Wangxi, HUANG Junhao
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 146-155.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The load effect on bridge structure is time-dependent. Here, based on Copula random number matrix of multi-dimensional random variable and Monte Carlo numerical simulation method, a time-varying reliability evaluation method for existing bridges with correlated load subject to stationary random processwas proposed. Taking historical load information subject to normal distribution as verification load, based on Pearson correlation coefficient matrix of adjacent load effects, N-element Gaussian Copula and t-Copula random number row vectors were constructed, respectively, and influences of load time correlation based on linear correlation on verification effect of bridge time-varying resistance were discussed. The time-varying reliability analysis was performed for a reinforced concrete beam bridge. The results showed that considering time correlation of load process can reduce its verification effect on bridge resistance; the stronger the correlation, the smaller the increase in mean value of resistance after verification and the decrease in its standard deviation, and the lesssignificant the verification effect; the verification effect of t-Copula function is lower than that of Gaussian Copula function; for bridges in service, the higher the time dispersion degree of load process verified by service history, the more unfavorable to the safety performance evaluation of structure in subsequent service period; using Copula random number matrix method proposed here, if t-Copula function is used to generate random number row vector, the value of degree of freedom df is suggested to be 1~20.
  • XIAO Pei, SU Xuan, MOU Haolei, XIE Jiang, FENG Zhenyu
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 156-164.
    Abstract ( ) Download PDF ( )   Knowledge map   Save

    Here, the failure morphology and load-displacement curve of [+45/-45]4s and [0/+45/-45/0]2s carbon fiber reinforced composite corrugated plates were obtained with quasi-static axial compression tests. Their failure mechanism was analyzed using CT scanning. Their energy absorption characteristics were further studied with evaluation indexes of energy absorption characteristics. For [0/+45/-45/0]2s corrugated plate, the multi-layer shell finite element (FE) model considering interlayer model was established to do axial compression simulation. The FE model was verified through comparing the simulation results of failure morphology, load-displacement curve and energy absorption characteristics evaluation indexes with test results of those. The test results showed that the overall instability of [+45/-45]4s corrugated plate occurs, and the lower material utilization rate leads to poorer energy absorption characteristics, the dispersion coefficient of the specific energy absorption (SEA) obtained in tests is more than 15%, so the test repeatability is poorer; [0/+45/-45/0]2s corrugated plate is a typical failure mode of layer-bundle opening, and the higher material utilization rate leads to better energy absorption characteristics, dispersion coefficients of energy absorption evaluation indexes all are less than 15%, so this plate has good axial compression stability and repeatability, adding 0° fiber layer into ±45° fiber layers can change the plate’s axial compression failure mode and significantly improve its axial compression energy absorption characteristics. The simulation results showed that the multi-layer shell FE model can reproduce axial compression process and layer-bundle opening failure mode of [0/+45/-45/0]2s corrugated plate; the SEA obtained using simulation is 2.27% higher than the test average value, so simulation can better reproduce axial compression energy absorption characteristics of [0/+45/-45/0]2s corrugated plate to verify the multi-layer shell model.

  • JIANG Shaofei, ZHU Hao, ZHANG Zhangrong, ZHAO Jian, WANG Yao
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 165-174.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    In order to quickly and accurately evaluate real state of irregular assembled frame shear wall structure under earthquake, and provide technical support for damage degree prediction and aseismic reinforcement of the structure after earthquake, based on structural material properties, interlayer deformation, torsional deformation and cracks and other parameters, the comprehensive damage index (DI) of the earthquake damaged irregular assembled frame shear wall structure was proposed to establish the relation between DI limit value and seismic damage level. Finally, the feasibility and effectiveness of the evaluation theory were verified with shaking table tests and numerical analysis, and the results were compared with those of the pulsation method and regulation evaluation. The results showed that using DI considers the structure’s local damage and overall damage states; seismic damage of irregular assembled frame shear wall structure is medium damage; compared with maximum interlayer torsion angle (serious damage) and crack (slight damage), the evaluation results can more truly reflect damage situation of seismically damaged structures, and they are consistent with overall evaluation results of the pulsation method and the maximum interlayer torsion angle method in code, so the proposed evaluation theory is feasible and effective for accurately evaluating seismic damage of irregular assembled frame shear wall structures.
  • SUN Fangjin, ZHU Donghan, ZHANG Daming
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 175-181.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the limitation of complex and time-consuming wind turbine blade fluid-structure coupled calculation, a reduced order model of wind turbine blade weak coupling calculation was proposed. The reduced order model of air-fluid equation in fluid-structure interaction calculation was established by using the proper orthogonal decomposition (POD) method. Base mode decomposition was done for unknown variables, such as, velocity and pressure of fluid control equation using POD method and they were represented by a small part of space modes. The fluid equation was discretized in time domain. The minimum residual projection of fluid control equation was obtained by using Galerkin projection method in the existing reduced space to construct the minimum residual reduced order model of fluid equation. Then, the fluid-structure coupled calculation was performed for the fluid reduced model and wind turbine blades. The reduced order model was applied in the fluid-structure coupled calculation of the classical NREL-V wind turbine blades, temporal discretization factors of the reduced order model and the classical Galerkin method were compared, and force and deformation varying characteristics of wind turbine blade were obtained and compared with those obtained with CFD. The results showed that the reduced order model is correct and effective; compared with the computational efficiency of the full order model, the reduced order model’s is greatly improved to save much time; the reduced order model can be used to accurately and effectively perform fluid-structure coupled calculation of wind turbine blades.
  • XIAO Bin, ZHOU Yulong, GAO Chao, CAO Yipeng, SHI Shuangxia, LIU Zhigang
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 182-187.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at problems of fluid-induced vibration (FIV) of structures, considering unidirectional fluid-structure interaction (FSI), effects of flow velocity on vibration characteristics of structure were analyzed through introducing added mass. A straight pipeline conveying fluid was taken as the study object, flow states in pipeline under different flow velocities were simulated with numerical method to obtain fluid pressure coefficient, turbulent kinetic energy and displacement response of pipeline structure. Based on the unidirectional coupling vibration mechanism, the pipeline FSI added mass model was established. The FE method was used to do the structural modal analysis, and calculate the structure’s added mass and natural frequencies due to fluid acting on structure. The numerical simulation results showed that pipeline internal fluid velocity has stronger coupling action on pipeline structure vibration, increase in flow velocity makes coupling added mass increase, and there is a critical flow velocity to cause pipeline having static buckling instability; compared with empirical formula, the calculation results here can more accurately reflect the fluid unidirectional coupling action on structural vibration within the error range of 10%; the proposed method can be applied in analysis of unidirectional coupled vibration problems, and provide a way for studying FIV problems in pipeline flow including effects of FSI on dynamic characteristics of structures.
  • LIU Liping, CUI Ming, XU Jun, YU Jie, ZHENG Xinyao, WANG Zhijun, LI Yingmin, LI Ruifeng
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 189-197.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, to improve aseismic performance of RC column-steel beam (RCS) joints, a box type RCS joint was proposed based on the column through type RCS joint. Based on low cycle repeated loading tests of 4 RCS box type joints, their failure characteristics, load-bearing characteristics and aseismic performance were studied. Effects of reinforcement of additional cover plate at the beam end, inner web spacing and thickness on failure mode, hysteretic energy dissipation characteristics and deformation of the joints were analyzed. The results showed that failure of joint specimens is concentrated in column end and beam end, and joint zone has no failure to meet the design requirement of “strong joint and weak member”; when specimens are damaged, their ductility coefficients are larger than 3.0, and their equivalent viscous damping coefficient are within the range of 0.16-0.27 to have good aseismic performance; joints’ shear forces are mainly exerted on inner web, while outer side plate mainly acts as stirrup and is subjected to parts of shear forces; increasing  spacing of inner webs can reduce restraint on end plate of steel beam and strains of inner webs, outer side plates, end plate of steel beam and flange of steel beam; cover plate can increase bending stiffness of beam end and strengthen constraint of  end plate of steel beam to reduce strain of flange of steel beam, and significantly increase strain of inner webs and end plate of steel beam; thickening inner webs can strengthen restraint of steel beam end plate to significantly increase strain of steel beam flange, slightly increase strain of steel beam end plate, and slightly decrease strain of inner web; designing box type joints should appropriately increase inner web spacing and choose larger plate thickness; the study results can provide a reference for designing RCS box type joints.
  • HE Keshan, CHEN Yan, QI Liangwen, ZHOU Qi
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 198-206.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The aerodynamic characteristics of trailing edge flaps were studied through wind tunnel test. The effect on airflow around the airfoil and regulation law of aerodynamic parameters by trailing edge flaps was discussed. As trailing edge flaps could fast response to wind loads, it could be used as an effectively supplementary means of individual pitch control of wind turbines. A combined pitch and trailing edge flaps control strategy was designed to mitigate fatigue loads and vibrations of wind turbines. The individual pitch control loop was mainly used to alleviate low frequency fatigue loads and vibrations, and trailing edge flap control loop was mainly used to alleviate high frequency fatigue loads and vibrations. The simulation results showed that this control strategy can effectively mitigate the low frequency and high frequency fatigue loads and vibrations of wind turbines, which has a broad prospect of engineering application.
  • LAN Guosheng, SUN Wan, TAN Wenbing, ZHANG Xueliang, WEN Shuhua, CHEN Yonghui
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 207-215.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, a micro convex body on rough surface was equivalent to a cone, combined with the fractal theory and the improved W-M function, the fractal model for normal contact stiffness of interface between two contact rough surfaces was established. Simulation calculations were done for the model. The results showed that the dimensionless normal contact load on interface increases with increase in dimensionless contact area, material plasticity index and dimensionless fractal roughness parameter; with increase in fractal dimension of rough surface, the dimensionless normal contact load firstly decreases and then increases, and reaches the minimum value when the fractal dimension is about 1.5; the dimensionless normal contact stiffness on interface increases with increase in dimensionless normal contact load and material plasticity index, and decreases with increase in dimensionless fractal roughness parameter; the dimensionless normal contact stiffness increases firstly and then decreases with increase in fractal dimension of rough surface, and reaches the maximum value when the fractal dimension is about 1.6; compared with test data, the correctness of the model is verified, the model can be applied in the related theoretical analysis and calculation.
  • ZHENG Deqian, ZHU Yuzhe, LIU Shuaiyong, MA Wenyong, FANG Pingzhi4
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 216-223.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    There is a close relationship between aerodynamic interference effect of two tandem square cylinders and characteristics of flow around square cylinder. The local shape change of corner of square cylinder can significantly affect aerodynamic interference effect of two square columns in series. Until now, the related studies are very few. Here, the 2-D unsteady  numerical simulation method based on Reynolds average SST k-ω turbulence model was adopted to study effects of no corner cut and corner cut (10%) on aerodynamic performance of the two tandem square cylinders. Comparing the numerical simulation results under conditions of no corner cut and the spacing ratio of 2.0 with test results in literature verified the effectiveness of the simulation method and parameter setting. Then, according to the contrastive analysis of lift and drag coefficients, critical spacing ratios of the two square columns in series without and with corner cut in upstream were determined to be 4.6 and 4.1, respectively. Finally, the 3-D unsteady flow around the two cylinders without and with corner cut was simulated using the spatially averaged large eddy simulation
    to analyze effects of upstream corner cutting on aerodynamic performance of the two cylinder in detail from the angle of wind pressure distribution. The mechanism analysis was performed in the aspect of time averaged  and transient flow fields around the two cylinders. It was shown that after corner cutting of the upstream square cylinder, the flow separates and reattaches in, wake flow becomes narrow, and vortex shedding becomes more complex to cause flow field’s  state varying, wind pressure distribution being affected, square cylinder’s lift and drag coefficients dropping, and critical spacing being shortened.
  • WAN Huaping, WEI Zhicheng, SU Lei, REN Weixin
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 224-231.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Pile-soil-structure interaction is an important problem in seismic response analysis of bridge structures, where pile diameter effect should not be ignored. Here, taking a three-span continuous beam bridge as an example, effects of pile diameter effect on bridge seismic risk was studied. Three kinds of finite element models of model1 simultaneously considering pile-soil-structure interaction and pile diameter effect, model2 considering pile-soil-structure interaction but not pile diameter effect and model 3 being a simplified model of pier bottom fixed were established. The seismic vulnerability curve and seismic risk curve of the bridge structure were calculated with the incremental dynamic analysis method. The contrastive analysis was performed for the calculation results of the three models. The results showed that model1 simultaneously considering pile-soil-structure interaction and pile diameter effect has the highest seismic vulnerability and seismic risk; model 3 with pier bottom fixed has the lowest seismic vulnerability and seismic risk.
  • LIU Mao, WANG Zhongmin
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 231-237.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Based on the absolute node coordinate formulation (ANCF), vibration characteristics of a homogeneous Euler-Bernoulli arch with variable cross-section were studied. Firstly, a homogeneous vibration model considering out of plane bending and torsion was established. In the global inertial coordinate system, it was divided into several arch elements with variable cross-section. The expressions of element’s kinetic energy, strain energy and potential energy of external forces were derived to obtain element’s mass matrix and stiffness matrix, and furthermore the arch’s mass matrix and stiffness matrix were assembled. Secondly, the arch’s bending-torsional vibration differential equation was established by using Lagrange equation. Finally, the first three order natural frequencies of equal cross-section circular arc arch and variable cross-section circular arc arch fixed at two-end were calculated numerically and the corresponding modal shapes were plotted. Effect laws of variable cross-section circular arc arch’s center angle, radius, height-width ratio and uniformly distributed radial load on its vibration characteristics were analyzed. The first three order natural frequencies of equal cross-section and variable cross-section parabolic type non-circular arc arches fixed at two-end were calculated numerically and the corresponding modal shapes were plotted.
  • CHI Zhaozhao, JIANG Juncheng, DIAO Xu, NI Lei, WANG Zhirong, SHEN Guodong, HAO Yongmei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 238-245.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The traditional acoustic attenuation positioning model needs determining pipeline operation parameters before positioning so as to calculate parameters involved in the attenuation model. Here, to solve this problem, a new sensor arrangement scheme was proposed, i.e., two sensors being placed in upstream and downstream of leakage point, and attenuation parameters being obtained with ratio values of experimental signal amplitudes between upstream and downstream sensors. The signal processing method of variational mode decomposition (VMD) was used to denoise experimental signals, and effects of different leakage diameters of 3, 6, 8, 10, 12, 15, 20, 27 mm and different detection distances on leakage signals were studied. Finally, MLE was used to do leakage positioning based on the attenuation model. The results showed that the proposed method can effectively locate leakages under conditions of different leakage calibers and different sensor positions; its positioning effect is better than that of the time difference method, and its error is within the range of 0~15%; the positioning error of knocking experiments is less than 7% to prove the effectiveness of the proposed method.
  • BAO Dan, HOU Baolin
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 246-252.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, aiming at multiple parameters with interval uncertainty existing in a SDOF manipulator system and the system being subjected to effects of external random disturbance during operation, a method based on deep learning neural network model was proposed to estimate positioning reliability of the manipulator. Firstly, the uncertainty analysis was performed for the system, and uncertain parameters in the system operation process were described using interval number to establish the uncertain model of the SDOF manipulator. Interval uncertain parameters could be regarded as fixed values in process of one action. Parameters of several sets of experiments were identified through combining experiment data and the parametric identification method, and the correctness of the simulation model of SDOF manipulator was verified. Secondly, Latin hypercube sampling was done for interval uncertain parameters and the sampled data were brought into the simulation model. The manipulator could realize positioning in external random disturbance to obtain sample data for training the neural network model, construct the neural network model based on levenberg marquardt (LM) algorithm, and perform Monte Carlo simulation analysis. It was shown that the positioning reliability of the SDOF manipulator is estimated as 84.12%. Finally, analyzing several sets of experimental data showed that the proposed method can have high efficiency and effectiveness, and provide a new idea for positioning reliability estimation of other nonlinear complex systems.
  • JIANG Hui, ZHANG Peng HUANG Lei, ZENG Cong
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 253-262.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Taking a simply supported steel box girder bridge across strike slip fault as the study object, simultaneously considering effects of uncertainty of ground motion and structural parameters, the incremental dynamic analysis (IDA) of the whole bridge structure under non-uniform excitation was performed, and probabilistic seismic damage characteristics of bridge piers across fault were deeply discussed. The results showed that effects of structural parametric uncertainty increase with increase in ground motion intensity; for pier adjacent to fault, when slip thrust strength of fault is 78.0 cm, the exceeding probability of complete failure rises from 7.53% of the mean model to 13.01% of the random model, so the vulnerability of the structure may be underestimated if not considering effects of structural parametric uncertainty under strong earthquake; when slip thrust strength of fault is 52.0 cm, exceedance probabilities of pier not adjacent to fault are 97.54%, 88.51%, 2.42% and 0.06%, respectively under four damage states, while those of pier adjacent to fault are 99.24%, 99.15%, 6.50% and 0.28%, respectively, so more attention should be paid to aseismic design of bridge piers adjacent to fault and targeted aseismic design should be performed.
  • LI Zheng, JIN Hao, ZHENG Jun
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 263-270.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    With rapid development of rail transit industry, effects of rail transit on vibration of masonry structures along rail line is more and more significant, and there is a phenomenon of local vibration amplification. Here, through establishing vehicle-track-tunnel-stratum-masonry structure coupled dynamic model, combined with masonry structure’s modal analysis, the masonry structure with 1-6 floors near a certain metro line was analyzed. The results showed that ① when B-type train is adopted and its running speed is 60 km/h, the masonry structure of lower floors (1-2 floors) along the line is less affected by metro operation, the masonry structure of higher floors (3-6 floors) has vibration response amplification phenomenon; when the total floors of masonry structure are 3-6, the horizontal vibration acceleration reaches the maximum value at the 2nd floor and the minimum value at the 1st floor; ② from the modal analysis results of  masonry structure, vibration response amplification may occur at 2-6 floors, the frequency range of vibration response amplification occurring at different floors is 23-46 Hz, and vibration response amplification at the 1st floor of the structure is not obvious; ③ vibration frequencies of masonry structure having vibration response amplification phenomenon are basically the same as natural frequencies of the structure, and under these frequencies, the floor where its response amplification phenomenon induced by train excitation occurring is basically consistent to the floor where its modal vibration maximum value occurring, so the train load induces natural modal vibration of masonry structure to cause vibration response amplification phenomenon.
  • FENG Qingsong, ZHOU Hao, CHEN Yanming, ZHANG Ling, LUO Xinwei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 271-276.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, to study characteristics of noise inside metro train in tunnel, the tunnel-car body finite element-acoustic boundary element analysis model was established. Based on the Metro B type car-rail coupled model and field tests, the car body secondary suspension force excitation and wheel-rail noise excitation were obtained. These excitations were exerted on the car body to simulate and analyze noise inside metro train. The simulation results were verified with the train noise test data of Guangzhou rail transit line 7, and effects of structural borne noise and airborne noise on noise inside metro train were studied. The analysis results showed that the change trend of sound pressure level diagram of each standard point in train is basically the same, the peak center frequency is concentrated at 630 Hz, the main frequency band is 200-1 600 Hz, the A sound level at the upper of car body bogie is about 1.02-2.35 dB (A) higher than that at car body center; the main influence frequency band of structure borne noise on car interior noise is 20-200 Hz, the main influence frequency band of airborne noise on car interior noise is 200-5 000 Hz, effects of the frequency band of 500-5 000 Hz are the most significant; when the train running speed is 60 km/h, the A sound level at car center under action of structural borne noise load is about 21 dB (A) higher than that at car center under action of airborne noise load; the study results can provide a theoretical basis for reducing car interior noise and improving car interior acoustic environment.
  • ZHANG Chunhui, LU Kaitian, LIU Hongquan, ZHANG Lei
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 277-293.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, aiming at the protection problem of equipment under strong impact environment, according to the calculation formula of annular gap damping coefficient, and based on double-out-bar damping structure, a Stewart anti-impact vibration isolation platform based on new damping structure was proposed. Through numerical simulation, energy-dissipating characteristics of new damping structure were compared with those of traditional double-out-bar damping structure under condition of SDOF. The results showed that the difference between the maximum damping forces of the two structures increases with increase in excitation frequency, the energy-dissipating of the new damping structure increases by 28%; through co-simulation of Adams and MATLAB, impact responses of Stewart platform with new damping structure and Stewart platform with double-out-bar damping structure were calculated; in vertical impact, the maximum difference between leg damping forces of the two platforms is 310 N, the reset time of Stewart platform with new damping structure is 49.7% shorter than that of Stewart platform with double-out-bar damping structure; while in inclined 45° impact, compared to Stewart platform with double-out-bar damping structure, the reset time of Stewart platform with new damping structure decreases by 26.2% in y direction and 36.3% in z direction; according to the positive and negative dual-wave testing results, the co-simulation calculation can accurately describe response characteristics of Stewart platform under impact, and reveal Stewart platform with new damping structure has better anti-shock damping capacity.
  • LUO Yuegang, FU Hao, ZHANG Yue, JIA Haifeng, HUANG Fengchao
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 284-289.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Here, based on the finite element method (FEM), a dynamic model of a double-span rotor system with slowly varying mass was established. By using Newmark-β numerical integration method, vibration characteristics of the double-span rotor system with slowly varying mass under conditions of different rotating speeds, different slowly varying parameters and different slowly varying positions were analyzed with shaft center trajectory diagram, Poincaré section one, time domain waveform one, frequency spectrum one and 3-D waterfall one. The results showed that when there is a slowly-varying mass in the system, a slowly-varying small frequency division Fr appears at ε times of working frequency, and equidistant frequency divisions with frequency interval of ε•Fn appear on both sides of working frequency and on the right side of Fr; the mass variation amplitude coefficient λ mainly affects vibration amplitude of the rotor system, when λ gradually increases, the amplitude of each frequency component of the system increases, and the system becomes more and more unstable; the slowly-varying time coefficient ε mainly affects the periodicity of the rotor system, when ε changes, multiple and period length of the system periodic motion change significantly; when both two disks of a double-span and dual-disk rotor system have slowly-varying mass, the periodic motion and frequency division components of the system are composed of the superposition of the two disks’, and phenomena near high rotating speed region become more obvious; the study results can provide a theoretical reference for studying dynamics and fault recognition of rotor systems with slowly varying mass in the future.
  • LIU Xiaofeng, WANG Bangxin, AI Fan, WEI Daiping
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 290-295.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    Aiming at the problem of it being difficult to distinguish matrix crack damage and delamination damage of composite laminates, Lamb wave was used to detect damages of composite laminates, feature extraction and screening of the received sensing signals were conducted, and the machine learning method based on weighted kernels-twin support vector machine (WK-TWSVM) was introduced innovatively to automatically classify and identify matrix crack and delamination damage. In order to further improve the accuracy of damage recognition, the simple particle swarm optimization (SPSO) algorithm was used to optimize kernel functions’ weights and model parameters, and SPSO algorithm was compared with other PSO algorithms. Test results showed that the damage identification method based on SPSO-WK-TWSVM and Lamb wave can automatically identify matrix crack and delamination damage of composite laminates, and its recognition accuracy is obviously higher than those of other TWSVM optimization algorithms and traditional machine learning methods.
  • SUN Qikai, ZHANG Nan, LIU Xiao, TAO Xiaoyan, WANG Zhangming, GONG Yiming
    JOURNAL OF VIBRATION AND SHOCK. 2021, 40(15): 296-302.
    Abstract ( ) Download PDF ( )   Knowledge map   Save
    The finite element (FE) calculation model for natural vibration characteristics of a steel-concrete composite beam based on dynamic direct stiffness method was derived considering shear-slip effect between concrete slab and steel beam, and the element dynamic stiffness matrix with 6-DOF was obtained. The solving process for natural vibration characteristics of a steel-concrete composite beam with general elastic supports was deduced. As no approximate displacement field or force field was introduced in derivation process of the model and it could be used to analyze steel-concrete composite beams with general elastic supports and variable stiffness in axial direction, the calculation results were accurate. Finally, through laboratory tests of a two-hole simply supported steel-concrete composite beam, the correctness of the FE calculation model was verified by comparing the calculation results of theoretical analysis, ANSYS and the derived FE model with test results. Meanwhile, the application scope of the FE calculation model was further verified by referring to the calculation results of the simply supported beam numerical model published in literature under 4 common boundary conditions of simply supported-simply supported, fixed-free, fixed-simply supported and fixed-fixed. The results showed that the derived dynamic direct stiffness matrix can be used to solve natural vibration characteristics of steel-concrete composite beams with axial variable stiffness under general elastic boundary conditions.