Stay cables of cross-sea cable-stayed bridges will generate self-excited vibrations in non-extreme wind environments. Based on technologies of modern monitoring and data analysis，the digital features of the self-excited vibration of the stay cable can be captured immediately，and the real-time performance of dynamics about stay cables can be reflected accordingly. According to features of commonality in the long-term monitoring data of vibrating acceleration of stay cables from a main channel cable-stayed bridge of a cross-sea bridge，an automatic extraction method for the non-stationary sections of wind-induced self-excited vibration of the stay cable is proposed based on the vibrating acceleration time series signal’s Gaussian mixture model of the upper envelope and the power spectrum of the frequency domain. The strategies，that identify the dominant frequency based on the non-stationary time series of self-excited vibration，then identify the damping ratio using the data of the last descent section after band-pass filtering，are proposed. By the proposed strategies，the interference on the damping ratio identification from energy brought by the natural excitation of the ambient wind in the ascent sections of the vibration amplitude is excluded. Based on the identified results of dominant frequency-damping ratio in the non-stationary sections of the self-excited vibration，data clusters of the modal frequency-damping ratio corresponding to each order of the vibrating mode are obtained by clustering the frequency values. According to the discrete and skewed characteristics of the damping ratio data，the statistical law of using the eμ of log-normal distribution model and the quantile value of its cumulative distribution function to describe damping ratio of stay cables is proposed. The frequency centroid of each cluster，as well as the probability characteristic parameter of damping ratio are used as indicators to represent the current state of the dynamic performance of stay cables. The main conclusions for the background engineering include： the signal of vibrating acceleration of stay cables on the bridge has strong noise and large interference，they must be eliminated in the analysis of dynamic characteristic； the amplitude maximum of the acceleration of the self-excited vibration of the bridge’s stay cable has exceeded 3000 mm/s²，the vibration amplitude is large； the average level of the damping ratio of the bridge’s stay cable is about 0.03%，which is lower than the recommended value of the design code.

In order to give full play to the seismic potential of the movable support pier and improve the overall longitudinal synergistic effect of the continuous girder bridge，based on the principle of functional separation and synergistic force，a new type of mass rotation wrap rope device is proposed based on the mechanism of wrap rope. Taking a typical three-span continuous girder bridge as an example，the shaking table test is carried out by inputting actual seismic waves with different seismic spectrum characteristics and intensity as excitation，the seismic response with equal pier height model and unequal pier height model are analyzed to explore the synergistic force and shock absorption effect of the device on the continuous girder bridge. Through the test results of the response of the key positions of the structure such as the acceleration response，displacement response and strain response，it can be seen that the effect of the device on the movable bearing pier participating in the overall longitudinal synergistic force of the continuous girder bridge is more obvious，and with the increase of the ground motion input intensity，the synergistic effect of the device becomes more and more prominent，the design intention of the device is realized. At the same time，the effect of the device is related to factors such as the number of wrap rope turns of the device itself，the pier height of the movable bearing pier，etc. The design needs to determine the reasonable design parameters of the device according to different factors such as the pier height to achieve the best effect of the device.

Most of the nuclear power plants are built around the coastal or along the rivers. Below the underground water level，distribution of the water in the soil pore has a great influence on the seismic response of soil，which affects the response of the nuclear power plants. To analyze the effect of the underground water level on the seismic response of nuclear power plant，a saturated porous medium model considering the interaction of the saturated soil and structure is used in this paper. Firstly，the free field of the horizontal layered site of dry soil-saturated soil is obtained by the transfer matrix method，and the wave input of soil-structure interaction analysis is realized combined with the transmission boundary； Then，the partitioned parallel calculation method of soil-structure interaction is used to analyze the saturated soil-structure interaction. The soil with groundwater level is described by the generalized saturated porous medium model which is simulated by the lumped-mass explicit finite element combined with the transmission boundary using the self-programmed FORTRAN code，and the structure is analyzed by ANSYS using implicit finite element. Taking a nuclear power plant as an example，the dynamic response of soil-base-nuclear power plant system is analyzed in five sites with different groundwater levels of -10 m，-20 m，-30 m and -40 m，as well as pure saturated soil. The results show that the groundwater level has a great influence on the response of foundation and structure. For the calculation example in this paper，the results show that the groundwater level has little effect on the displacement of the foundation and structure，but has a great effect on the acceleration of the foundation and structure.

To address the threat of harmful vibrations of semisubmersible floating offshore wind turbine （FOWT） in complex deep-sea environments to the safety and durability，a design of distributed tuned mass dampers （TMDs） is proposed to control the platform pitch motion under the randomly combined wind and wave excitations，in combination with the geometric structure of the 5MW prototype of NREL in the United States. The distributed TMDs are installed inside the platform to form an equilateral triangle arrangement. To better describe the performance of the distributed TMDs on the semisubmersible FOWT，a 9-degree-of-freedom multi-body dynamics model is proposed and established for the coupled semisubmersible FOWT-TMDs system based on Lagrange's equation and the modal superposition method. Based on the H_∞ algorithm，whose optimization objective is the peak value of the frequency response function of platform pitch motion，the parameters of the distributed TMDs are optimally designed，where the coupling relationship between multiple TMDs is considered. The numerical simulation of the coupled FOWT-TMDs system under the combined wind and wave excitations is carried out to analyze the performance of the distributed TMDs on the platform pitch response of the wind turbine. The results show that the distributed TMDs with optimal design has good damping performance on the platform pitch motion of the semisubmersible FOWT. Under random wind and wave loads in three different working conditions，the peak and standard deviation vibration reduction rates of the power spectral density curve near the natural frequency of platform pitch can reach more than 39% and 52%，respectively. The research method and results can provide reference for dynamic analysis and vibration control design of large semisubmersible FOWT.

There is a lack of detection means for the isolation performance of the buildings built by passive control technology，so it is of great significance to test the dynamic characteristics of the isolated structures on the spot. A 4-story base isolation kindergarten was tested in the field，and the test device，method and results were displayed. The results were compared with the seismic structure model under the same conditions，and the dynamic response law and damping effect of the actual isolation structure were explored. The building was pushed away with hydraulic jack to produce 98 mm （corresponding to LNR500 shear strain 102%） horizontal initial displacement of the isolation layer，and concrete jacking rod was installed to support the building； The concrete rod was blasted with explosives and unloaded instantly to make the building vibrate freely； The dynamic response and other parameters were tested and analyzed. The results show that under the condition of horizontal initial displacement，the first-order natural vibration period of the isolated structure is significantly longer than that of the seismic structure，and the damping ratio increases； The hysteretic curve of the isolation layer is full； The dynamic response control effect of each floor is obvious，but the acceleration of the roof floor is slightly amplified compared with that of the bottom floor； After unloading，the isolation layer instantly resets，which shows that the isolation layer has rapid reset performance.

To reveal the influence of biaxial coupling effect on the multi-dimensional seismic performance of flanged reinforced concrete （RC） shear walls with different section forms，three T-shaped and two L-shaped RC shear walls were tested under low cyclic loading along their principal axes. The failure modes，hysteretic characteristics，bearing capacity，ductility，ultimate drift ratio，energy dissipation capacity and reinforcement strain of RC shear walls with flange under uniaxial and biaxial lateral loading were compared and analyzed. Test results show that failures of T-shaped walls and L-shaped walls exhibit obvious asymmetry，and the damage is concentrated at the free end of wall penal. Biaxial loading aggravates the cracking and damage degree of RC shear wall with flange，and is likely to cause local damage concentration. Compared with the RC shear wall with flange under uniaxial loading，the biaxially loaded specimens have smaller bearing capacity and deformation capacity in all directions，larger proportion of flexural deformation in the plastic hinge area of web segment，faster energy consumption，poorer energy dissipation capacity in a single direction，larger strains of vertical reinforcement in web and flange，and more obvious shear lag effect of flange. Biaxial coupling effect has more pronounced influence on the damage evolution of L-shaped walls than that of T-shaped walls，resulting in greater reduction of seismic performance index of L-shaped walls under biaxial loading than that of T-shaped walls. Considering the biaxial seismic actions，the limit value of inter-story drift ratio of RC shear walls in China's seismic design code is still relatively safe，but the safety redundancy is reduced.

In order to accurately analyze the influence of temperature and shear deformation effects on the natural vibration characteristics of the improved composite box girder with corrugated steel webs，a method for analyzing the natural vibration characteristics of an improved composite box girder with corrugated steel webs considering temperature and shear deformation effects is proposed in this paper. Considering the influence of the temperature，shear deformation and stiffness correction of the corrugated steel web，the analytical formula of the natural frequency of the improved composite box girder with corrugated steel webs is deduced by using the principle of stress equivalence； The correctness of the analytical formula of natural frequency is verified by using the ANSYS finite element results and the measured results of bridge； The effects of temperature equivalent axial eccentric force，variation of elastic modulus，shear deformation，and temperature effect under different height-span ratios and different width-span ratios on the natural frequencies of bridge are analyzed. The results show that the fundamental frequency of the improved composite box girder with corrugated steel webs is greatly affected by the temperature effect，and the influence of the temperature effect needs to be considered when calculating the fundamental frequency of this bridge type； The shear deformation effect of the corrugated steel web has a significant influence on the natural frequencies of the bridge type，and the influence of shear deformation from the 4th order natural frequencies has exceeded 50%； Under different height-span ratios，the temperature effect has a greater influence on the fundamental frequencies，and it increases linearly and sharply with the increase of the height-span ratios； Under different width-span ratios，the temperature effect has little influence on the natural frequencies and can be ignored. The research results can provide a reference for the calculation and analysis of the natural frequencies of the improved composite box girder with corrugated steel webs.

In order to explore the influence of the traction motor distribution on the dynamic characteristics of rack vehicle and gear-rack meshing characteristics，the vehicle dynamics characteristics under different traction motor layout modes are analyzed with the consideration of the gear-rack nonlinear meshing behavior and dynamic time-varying excitation and the wheel-rail nonlinear contact relationship. Based on the Strub system，the coupling dynamics model of rack vehicles is established. The influence of three different motor forms on the dynamic characteristics is studied. On this basis，the layout mode suitable for rack vehicles is proposed.The research shows the gear meshing force and the vertical and longitudinal vibration acceleration are smaller under the dual-mounted traction motor conditions. When the motor is dual-mounted，the meshing force is about 50% of that the motor is rear-mounted and front-mounted. The maximum amplitude difference of the vertical and longitudinal acceleration of the gear is 4.04 m·s^-2 and 6.01 m·s^-2 in the straight section. When the motor is rear-mounted the gear vibration acceleration is the largest，and the vertical and longitudinal acceleration amplitudes are 45% larger than the dual-mounted traction motor conditions in the climbing section. The comfort of rack vehicle is better when the motor rear and front-mounted on the straight line，but the dual-mounted is better in the climbing section. In view of the fact that rack vehicle is mainly used in climbing lines，and the dynamic characteristics of rack vehicle with dual-mounted are the best when climbing. Thus，it is recommended that the dual-mounted is the optimal layout mode.

In this paper，a set of overlapped and laminated foil aerodynamic bearings was developed，which was composed of overlapped radial bearings and laminated thrust bearings. Meanwhile，a rotor test bench of the foil aerodynamic bearings was designed and built. The take-off characteristics of the proposed foil aerodynamic bearings were studied by comparing the speed drop experiments of multiple groups of rotors. The influence of rotor unbalance and external load on the rotor dynamics of the bearing-rotor system was analyzed. The take-off test results show that the take-off speed of the radial foil pneumatic bearing developed in this paper is about 7500 r/min，and the maximum take-off torque is about 220 N·mm. The experimental results show that with the increase of rotor unbalance，the 1X frequency vibration amplitude increases gradually，the second critical speed decreases gradually，and the frequency of secondary frequency vibration increases gradually. With the increase of rotor speed，1X frequency vibration of the rotor system firstly increases and then decreases，and the amplitude of secondary frequency vibration increases gradually. When the center distance of the top foil structure is reduced，the stability of the rotor system increases. The experimental results show that both the unbalance and the external load excite the secondary frequency vibration of the system，and the amplitude of the secondary frequency vibration increases with the increase of the rotational speed. Moreover，the unbalance and the external load have obvious amplifying effect on each other in the excitation of secondary frequency.

In this paper，a fractional-order time-delayed feedback controller is designed to control the nonlinear dynamic response of a single-degree-of-freedom giant magnetostrictive actuator （GMA）. Considering the effect of geometric nonlinear factors introduced by the preloaded disc spring mechanism，a nonlinear mathematical model of the GMA system is established. The amplitude-frequency response equation of the main resonance of the system under the feedback control strategy with fractional-order time-delayed is obtained by the averaging method，and the stability condition of the system is obtained according to the Routh-Hurwitz criterion. The influence of key structural parameters in the GMA system on the amplitude-frequency response characteristics，as well as the characteristic law of the main resonance peak and system stability with each time-delayed feedback parameter are studied through numerical simulation. The bifurcation diagram and Lyapunov exponent diagram are obtained and the influence of the external excitation amplitude on the chaotic motion of the system is studied； finally，the time-delayed feedback gain and fractional order are used to suppress the chaotic motion of the system. The results show that the time-delayed feedback gain and fractional order can effectively suppress the main resonance peak and unstable region of the system，and the system response can be adjusted from chaotic motion to stable periodic movement to improve the stability of the system.

The shock signals in the process of road transportation cause the non-Gaussian characteristics of random vibration process. In order to study the impact of shock on product damage，the measured 8 vibration signals of medium truck and heavy truck are statistically analyzed. The vibration signals are divided into 20% high-intensity non-Gaussian signal，60% medium-intensity Gaussian signal and 20% low-intensity Gaussian signal. The finite element software is used for time-domain vibration analysis to calculate the damage proportion of each signal segment. The results show that the non-Gaussian signal contains high intensity shock signal，which causes the most of damage. The shock amplitude of medium truck vibration data is large and accounts for a small proportion，while the shock amplitude of heavy truck is relatively low and accounts for a large proportion. The higher 5% shock signal for medium trucks caused more than 90% of the damage； The 20% non-Gaussian signal of heavy truck contains 10% higher amplitude vibration besides 10% shock component，and the damage caused by 20% non-Gaussian signal is about 80% or higher. In the whole transport vibration process，the shock signal dominates the accumulation of damage with less content.

The shortcomings of fault diagnosis methods based on deep convolutional neural networks is that，tensor data is easily destroyed when reducing the dimension of high-order input tensors by pooling layers，which results in a loss of data information，and the relatively complex network structure. Therefore，a Deep TensorProjection Networks method is constructed via replacing the pooling layer in the traditional CNN by a TensorProjection Layer. The TensorProjection Layer reduces the dimensionality of input high-order tensor data without causing damage to the data，thus avoiding the impact of the loss of feature information，and greatly improving the recognition accuracy of the model. The dimensionality of the TensorProjection Layer used for dimensionality reduction is variable，thus simplifying the networks structures. Based on this，combined with the respective advantages of high-order spectrum and deep TensorProjection networks，a mechanical fault diagnosis method based on deep TensorProjection networks is proposed. In the proposed method，the feature of fault signal is extracted by high-order tensor spectrum，which is input into the constructed model for reducing high-order tensor dimensionality and identifying faults. The proposed method is applied to diagnose gearbox faults. Experimental results show that the proposed method can better retain the original fault information and effectively recognize the different types of faults. And the accuracy is better than traditional deep convolutional neural network fault diagnosis methods.

Intelligent fault diagnosis of rolling bearings is important for guaranteeing the safe of equipment. However，the non-stationary conditions lead to the incomplete collected training datasets，which makes the data-driven model learn the limited diagnostic knowledge. This declines the testing accuracy observably. To solve this problem，a Standard Self-Learned Data Augmentation （SSDA） fault diagnosis method is proposed，which can generate disturbed samples to expand the completeness of the original dataset. The method includes two training steps： standard self-learning and data augmentation. The training process of one-dimensional convolutional neural network is regarded as the self-learned standard of model to judge disturbed samples. Based on this standard，sample parameterization and model datalization are used to generate disturbed samples. By alternately carrying out the two steps，not only the disturbed data can be generated to augment the completeness，but also the fault diagnosis model under non-stationary conditions can be obtained. In addition，by studying the sample differences with different data generating number，it is found that the randomness of distance and direction is superimposed on the randomness of the proposed method to guaranteeing the diversity of the generated samples. Experimental results show that the proposed method is effective and advantageous in diagnosing bearing fault with incomplete training data sets under non-stationary conditions.

Aimed at the problem of limited placement of error microphones in large-scale spatial active noise reduction systems，this paper used the virtual error sensing technology to place multiple virtual error microphones in the noise reduction target area，and transferred the quiet zones from the physical error microphone points to the virtual error microphone points，expanded the range of the quiet zones in the noise reduction target area. In order to analyze and study the noise reduction performance and influencing factors，the principle and algorithm of multi-channel virtual error sensing were given first，and then the noise reduction performance and the number and placement of physical and virtual error microphones ware simulated and analyzed. Finally，the noise reduction performance and influencing factors were verified experimentally in a model cabin of a turboprop aircraft. The simulation and experimental results show that the used virtual error sensing was beneficial to increase the average noise reduction and quiet zone of the target noise reduction area，the placement of the physical and virtual error microphones directly affects the distribution of the quiet zones，a reasonable number and placement of physical and virtual error microphones can expand the quiet zones to cover the noise reduction target area 100%，and the optimal number of error microphones was related to the noise frequency characteristics of the primary sound field.

Honeycomb sandwich panels are widely used in aerospace and other major equipment because of their light weight and excellent mechanical properties. The acoustic performance，however，is a significant flaw. In this study，a sound insulation prediction model of infinite honeycomb sandwich panel is established based on the Bloch theorem and the wavenumber finite element method. The honeycomb sandwich panel is simulated with a periodic cell. By analysing the dispersion characteristics of the honeycomb sandwich panel in the wavenumber domain，the sound insulation mechanism under the excitation of diffuse sound field is revealed，and the influence of geometrical parameters on the sound insulation performance of the honeycomb sandwich panel is investigated. The results demonstrate that below the critical frequency，the sound insulation of the honeycomb sandwich panel is mainly controlled by the mass law，while above the critical frequency，the sound insulation is also impacted by the structure's own feature wave. When the incident acoustic wave excites the resonance of the feature wave，the sound insulation fluctuates with frequency and generates a sound insulation valley. The effect of thickness variation on the sound insulation performance is primarily related to the amount of sound insulation below the critical frequency，the thicker the honeycomb sandwich panel，the higher the amount of sound insulation； height increase reduces the mass law control zone and shifts the first sound insulation valley to lower frequencies，resulting in a weakening of the overall sound insulation performance. The relevant research results can provide a reference basis for the design of vibration and noise reduction of complex structures.

The flexible structure in probe-drogue aerial refueling system often occurs the hose whipping phenomenon in different degrees，which greatly affects the safety of aerial refueling mission. Based on flexible multibody dynamics，a dynamic model of aerial refueling system is built. The large deformation，large-scale movement and variable length characteristic of the hose are described by beam element that based on arbitrary Lagrange-Euler description and absolute node coordinate method. The aerodynamic model on the aerial refueling system is built，which can reflect the coupling effect between the movement of the tank and the receiver，the deformation of hose and aerodynamic force. Based on the dynamics model，the hose whipping phenomenon in flight is reproduced，and the formation mechanism of the phenomenon is obtained. The research shows that the docking impact is the main cause of whipping phenomenon，which changes the equilibrium state of the hose and causes shear waves to propagate and reflect back. The results of multi-case simulation are used for analyzing the influence law of various factors，including hose stiffness，docking speed and Mach number，on the shear force，longitudinal wave and shear wave propagation speed of the hose when whipping phenomenon happened. The effectiveness of hose reeling in/out control and buffered probe for vibration suppression of hose whipping phenomenon is also analyzed，which provides an important reference for improving the safety of probe-drogue aerial refueling system.

The braking torque of the carbon ceramic braking system of the landing gear increases with the reduction of wheel speed under the condition of rapid change of angular speed. The negative slope of the braking torque and wheel speed curve has a great relationship with the landing gear walking vibration. Focusing on the impact of the negative slope of the braking torque on the landing gear brake vibration，a three degree of freedom landing gear brake walking model is established，and the main landing gear brake vibration of amphibious aircraft is analyzed. The calculated acceleration response and frequency are consistent with the test results of the landing gear field skid brake test. The effects of initial braking torque，negative slope，landing gear heading stiffness and damping，strut equivalent height and other parameters on the landing gear dynamic system are studied，and the dual parameter vibration convergence boundary of initial braking torque and negative slope of braking torque under high speed braking is given. By means of Hopper bifurcation analysis，the two parameter stability boundary of the negative slope of braking torque and velocity under the global state of the landing gear system is given. Through analysis，it is concluded that the gear walk may be caused by two reasons： the negative slope of the braking torque exceeds a certain range，or the braking torque is too large due to large braking pressure，and the slip ratio exceeds the limit. Compared with high speed braking，the negative slope of braking torque has greater influence on the stability of low speed braking. Finally，based on the analysis results，the methods and suggestions to improve the gear walking vibration of landing gear are given.

Abnormal vibration often occurs in the liquid oxygen kerosene transmission pipeline of the rocket engine，which seriously threatens the safety of the rocket engine. Improper handling will result in a failed rocket launch and enormous economic losses. Therefore，it is necessary to study the vibration of the transmission pipeline. In this paper，a three-dimensional high pressure transmission pipeline model comprising a corrugated pipe，a multi-section bending pipe and other auxiliary structures is established.Using the two-way fluid-solid coupling method，the vibration analysis of the pipeline is performed under external pressure pulse excitation. The accuracy of the computation results is verified by a thermal test. The results show that at the same frequency，the amplitude distribution of vibration acceleration obviously correlates with the amplitude distribution of flow field pressure，which indicates that the fluid pressure fluctuation is the root cause of abnormal vibration of pipeline.And the vibration of pipeline increases with the increase of average pressure. In the visualization results，the location of pipeline vibration is mainly concentrated in the middle pipeline and bellows. The stress and strain of the pipeline are concentrated at the bellows，bends and supports，which is different from the distribution of vibration acceleration. The position with large stress and strain is the dangerous position where the structure is prone to failure，which should be paid more attention to.