To investigate the vibration and acoustic properties of the baffled functional gradient plates with general boundary conditions under turbulent excitation，a vibro-acoustic coupling model of the functional gradient plate under turbulent boundary layer wall pressure fluctuation is developed by the energy method based on the turbulent pressure fluctuation cross-spectral density，Chebyshev spectral method，Rayleigh integral and the continuity condition of the fluid-structure coupling surface. The accuracy of the algorithm is verified by the agreement with the analytical solution and experimental results. The effects of the general boundary condition and the gradient index of the FGM plate are studied. It can be noted that when the stiffness of the boundary spring is in a certain range，the peak frequencies of the flow-induced acceleration level and sound pressure level increase with the rise of the spring stiffness. When the stiffness of the boundary spring is large，low vibration and radiated sound exist at low frequency，while the radiated sound pressure is high at high frequency. As the gradient index increases，the peak frequency increases gradually，but the peak responses of the acceleration level and sound pressure level decrease.

Self-centering brace has greater stiffness and bearing capacity after being activated. The brace connection，beam and column are subjected to more complex forces and higher risk of damage. A novel frictional prefabricated connection node in self-centering braced steel frame is proposed to control ultimate axial force of the self-centering brace by frictional slipping. It provides additional energy dissipation for the whole structure. Configuration，assembly and working principles of the connection nodes are described. By numerical simulation，its seismic performance is studied. The effects of design parameters of the connection node on performance are analyzed. The results show that the hysteretic response of the self-centering braced steel frame with the novel connection node is fuller. The energy dissipation capacity of the overall structure is increased by 20.81%. The actual limiting effect of the connection node on total shear force reaches 17.56%，effectively regarding the plastic development of connection node region. By changing the friction coefficient of the friction plate and the preload force of the high-strength bolts of the connection node，the slipping displacement and force can be adjusted.

In recent years，inflatable membrane structures with rectangular planes have been widely used in large-span coal bunkers and other facilities. However，the wind-induced vibration coefficients for these structures are not provided in design standards. In this paper，the wind loads on inflatable membrane structures with rectangular planes for typical rise-span ratios are obtained through wind tunnel tests. The wind-induced responses are calculated via a nonlinear dynamic time-history analysis method. The influences of different parameters such as wind velocity，wind direction，span，rise-span ratio，and internal pressure on the deformations and extreme responses are investigated. The results show that the mean structural deformation is characterized as concave on the windward and leeward regions and convex on the top and side regions. The spatial distributions of extreme responses are significantly influenced by the structural parameters and wind directions. Additionally，the wind-induced responses are positively correlated with the spans and rise-span ratios. The structural wind resistant performance can be strengthened by enhancing internal pressure to some extent. The internal pressure is recommended between 400 and 500 Pa. The wind-induced vibration coefficients of displacement and stress are provided for engineering reference.

Structural response of quay crane should be paid more attention to with the growth of worldwide logistics demand. This paper analyzes the response mechanism of the metallic structure of the quay crane induced by trolley traveling. On-site test is conducted. The time domain of crane girder acceleration signal shows that the main influence of the trolley travelling on crane structure is the high-frequency impact as it passes through the hinge point. The spectrum shows the main frequency of structure vertical vibration and impact vibration. Based on Euler-Bernoulli beam theory，a numerical model of quay crane single beam structure is established. The influence of different working conditions on the dynamic response of the beam structure and effect of the centrifugal acceleration term in the dynamic equation on logistics equipment such as quay cranes is analyzed. A refined model of the whole structure including the critical parts of the structure，such as the hinge points，the rail girder and other structural geometric features is established. The trolley is simulated with simplified mass points，and the interaction between the trolley and the girder is realized by the contact between the mass and the shell elements in the dynamic analysis of the quay crane structure. The eccentric force of the rail girder is considered，and the acceleration response of the girder hinge point is calculated，which is basically consistent with the measured signal results. After calculation and analysis，the frequency spectrum of the measured acceleration signal and the calculated signal spectrum at the girder hinge point of the quay crane show that the main influence of the trolley traveling on the quay crane structure is the high-frequency impact. The influence of the impact on the surrounding structure cannot be ignored. At the same time，the displacement results of 10 measuring points on the girder of the quay crane model and the trolley show that when the trolley runs at a constant rated speed with the rated load，the front end of the girder of the quay crane produces a vertical quasi-static displacement. The displacement spectrum indicates that the trolley is mainly affected by the vertical direction forced vibration.

Based on the dynamic response caused by moving vehicles，a recurrence quantification analysis-based structural damage detection method is proposed. The acceleration response is split into several segments using a moving window. The recurrence plots are constructed to analyze and present the characteristics of each segmented response signal. The recurrence quantification analysis is used to quantify the damages and construct the damage feature. The damage features of each relative position are assembled as a vector for the location of the structural damage. The proposed method is validated by numerical simulation with the single-damage and multi-damages. The influence of damage location，vehicle speed，noise and other factors are discussed to illustrate the robustness of the proposed method. Results show that the method is a potential way for structural damage detection under operational condition.

The existing rectangular piezoelectric cantilever beam has the shortcomings of high intrinsic frequency and low output performance. In this paper，a piezoelectric energy harvester based on the enhanced negative Poisson’s ratio structure is designed by combining a negative Poisson’s ratio structure and X-shaped ribs in an elastic substrate. The dynamics model of the energy harvester is established by using the finite element method for the piezoelectric coupling analysis and parametric analysis. The prototypes are fabricated to verify the design. The results show that the energy harvester based on enhanced negative Poisson’s ratio structure has a low first-order resonant frequency，high output voltage and power，and the addition of X-rib increases the stiffness and nonlinearity of the structure. Compared with the conventional negative Poisson’s ratio structure，the introduction of X-rib not only improves the fatigue performance of the structure，but also broadens the bandwidth by 67.87%. The energy harvester based on enhanced negative Poisson’s ratio structure is important for solving the power supply problem of wireless sensors and portable electronic mobile devices in the future.

Seismic vulnerability analysis is one of the most effective tools to evaluate seismic performance of pile-supported wharf （PSW） structures，which can quantify the probability of structural damage under given ground motion parameters. For a typical PSW in this study，the degradation of steel and concrete materials caused by chloride ion induced erosion is explored. Based on the open-source numerical computational platform OpenSees，a two-dimensional finite element model of PSW is created. In this model，the cross-section characteristics of pile considering corrosion effect are adopted in splash zone. The influence of chloride ion induced corrosion on seismic performance of PSW structure is discussed. Pushover analysis method is used to determine the seismic demand bound limit of each damage state of PSW. By inputting 80 ground motions to wharf models with different corrosion years，the logarithm regression analysis for the ratios of the capacity and demand are adopted to develop the time-dependent seismic fragility curves. The results show that： Chloride ion induced corrosion leads to the decrease of deck displacement and pile top bending moment，and the slight increase of pile top curvature； During the whole service life of PSW，seismic vulnerability of wharf structure in different damage states increases with an increase of service time.

Dynamic actions such as strong winds and earthquakes often have significant randomness and non-stationarity，which can have disastrous effects on practical engineering structures. Therefore，accurately evaluating the dynamic reliability of high-dimensional nonlinear systems under non-stationary stochastic excitations is crucial for the disaster-resistant design and optimization of these structures. This paper presents a numerical method for solving the high-dimensional nonlinear dynamic reliability under non-stationary noises，based on the globally-evolving-based generalized density evolution equation （GE-GDEE） for generic continuous processes. Specifically，if we are concerned with the first-passage reliability of a quantity of interest within a specified safe domain，an absorbing boundary process （ABP） of the quantity of interest can be constructed. This leads to a two-dimensional partial differential equation for its transient probability density function （PDF），known as the GE-GDEE for ABPs. The effective drift coefficient in the GE-GDEE，which serves as the global physical driving force for evolution of the PDF，can be identified using data from representative deterministic dynamic analyses. The solution for dynamic reliability can be obtained by solving the GE-GDEE. This paper includes two numerical examples to verify the efficiency and accuracy of the proposed method and discusses areas that require further study.

This paper proposes a fault diagnosis method for rolling bearings under variable speed conditions，based on the Adaptive Window Rotation Optimization Short-Time Fourier Transform （AWROSTFT）. This method addresses the issue of low energy concentration caused by the fixed window effect in Short-Time Fourier Transform （STFT）. Variational Mode Decomposition （VMD） is used to reduce the noise of the original vibration signal，and Particle Swarm Optimization （PSO） is employed to solve the complex problem of VMD parameter selection. A series of rotation operators are adaptively matched to the horizontal window in STFT using the tangent idea，aligning the rotation direction of the window with the instantaneous frequency modulation to improve the energy concentration of time-frequency representation. The instantaneous frequency，extracted by the spectral peak detection method，is divided by the frequency transformation curve. The result is matched with the fault characteristic coefficient of the bearing to achieve fault diagnosis of the rolling bearing under variable speed conditions. The results of simulation and experimental signals show that the proposed method effectively combines the advantages of PSO-VMD and AWROSTFT. Through the adaptive rotation window with the idea of tangency，the angle between the signal and the window function is globally reduced to zero，improving energy concentration，sharpening the time-frequency ridge line，and enabling fault diagnosis of rolling bearings under variable speed conditions.

In the design phase of a mine hoist’s main bearing，the reliability analysis of its random vibration cannot obtain complete probability information of the vibration acceleration response due to insufficient experimental samples. This paper proposes a new technical route for the reliability analysis of the main bearing of a mine hoist under incomplete probability information. This route includes the dynamic model of a multi-scale coupling system for rolling element bearings，the probability density evolution of vibration acceleration，stochastic process modeling of the probability density evolution path，the probability distribution of vibration power spectral density，and the calculation of design reliability based on conditional probability. By using the collected condition data to drive the established dynamic model of multi-scale coupling system for rolling element bearings，the probability density evolution of vibration acceleration is carried out. Based on the probability density evolution and Karhunen-Loève expansion，a modeling approach for the non-stationary random process of vibration acceleration of rolling element bearings is proposed. This approach obtains the twin data of the random sequence of vibration acceleration for rolling element bearings. The probability distribution of the vibration power spectral density for the main bearing of a mine hoist is studied，and the reliability index of the main bearing of a mine hoist within the service time is calculated.