To address the problems of large number of random variables and time-consuming computation in the simulation of non-stationary non-Gaussian stochastic processes，a fast computation method of non-stationary non-Gaussian stochastic processes is proposed based on sample interpolation by combining the stochastic harmonic function. With the known of the target evolutionary power spectrum and target density function of non-Gaussian stochastic processes，the correlation function equations of non-Gaussian stochastic processes and underlying Gaussian stochastic processes are established through Mehler’s formula，and a fast calculation method for the evolutionary power spectrum of underlying Gaussian stochastic processes is proposed through interpolation method. Subsequently，a fast simulation method for non-stationary non-Gaussian stochastic processes is proposed by combining stochastic harmonic functions，The effectiveness of this method is verified by simulating single-point uniformly modulated non-Gaussian stochastic process and multi-point non-uniformly modulated non-Gaussian stochastic processes. The results show that，when calculating the evolutionary power spectrum of the underlying Gaussian random process under the condition of ensuring accuracy，the calculation time of interpolation solution is lower than that of Mehler’s formula solution，and as the number of excitations increases，the efficiency of interpolation solution in calculating the evolutionary power spectrum of the underlying Gaussian random process is more obvious. The proposed fast computational method of non-stationary non-Gaussian stochastic processes can effectively simulate the non-Gaussian stochastic processes with the target evolutionary power spectrum and the target density function.

Time-delay has significant influence on the performance of control systems and the stability of controlled structures，which，to a certain degree，limits the application of active control techniques in practical engineering. Although the time-delay classical optimal control method can consider the influence of time-delay，the time-delay problem needs to be transformed into a delay-free problem through introducing an augmented state vector associated with the control forces within the time-delay interval. Therefore，the augmented Riccati equation needs to be solved，leading to a large amount of computational cost for the design of control law. This paper is devoted to developing a time-delay explicit optimal control method of structures. The explicit time-domain expressions of dynamic responses are first established for the system with time-delay control. On this basis，the time-delay explicit optimal control law can be analytically derived from an unconstrained linear quadratic optimization problem. As the effect of time-delay control force on structural dynamic responses can be readily considered with the aid of the explicit time-domain formulation，the time-delay explicit optimal control law can be derived without augmented treatment of the state vector and solving of the Riccati equation. A numerical example involving a three-storey shear-type structure with an active controller subjected to seismic excitation is presented to investigate the effect of time-delay and validate the feasibility of the proposed method.

In order to improve the dynamic output performance and environmental adaptability of the tri-stable piezoelectric energy harvester （TPEH），a new flexible tri-stable piezoelectric energy harvester （FTPEH） with double flexible auxiliary beams for real-time adjusting the potential well depth and barrier height is proposed. Based on the traditional magnetic coupling tri-stable piezoelectric energy harvester，two auxiliary flexible beams with the same structure and size are introduced，and the two external magnets are fixed at the tip ends of the two auxiliary flexible beams. When the harvester is excited by the external excitation，the two auxiliary beams oscillate with slight amplitude in the horizontal direction，thus the horizontal distance between the external magnets and the tip magnet of the piezoelectric cantilever beam can be adjusted in real-time，so as to tune the potential energy well depth and barrier height，resulting in improving the dynamic output performance and environmental adaptability. The electromechanical coupling dynamic model describing the dynamic responses of the new tri-stable piezoelectric energy harvester is established based on Euler Bernoulli theory and Hamilton principle，and the influences of system parameters on the nonlinear magnetic force and dynamic performance are simulated and analyzed. Compared to the traditional tri-stable harvester，the new tri-stable harvester has a wider bandwidth of inter-well motion and lower excitation for jumping from intra-well motion to inter-well motion.

A large number of high-pier rigid frame bridges in the canyon areas are located in near-fault regions （hereinafter referred to as near-fault），and the seismic analyses should comprehensively consider the near-fault effect，site effect，and fluid-structure interaction when they are located in the water environment such as rivers，reservoirs，etc. Currently，most near-fault seismic records are used as consistent inputs，which may underestimate the seismic response of the bridges. At the same time，the discussion on the correlation between the seismic sources，site parameters，and seismic response of the bridges is unexplored. In this paper，the stochastic finite fault method and the boundary element method are combined to generate the multi-dimensional and multi-point ground motions of the overlying water-layer canyon sites near faults，and the analysis of the seismic response of the deep-water，large-span，high-pier rigid frame bridge in the near-fault canyon site is developed. The sensitivity of the response of piers and bearings to the seismic source and site parameters is investigated from the perspective of the whole physical process between the seismic source and the structure. The results indicate that the bridge response is most sensitive to the rupture surface size. On the whole，the influence of source parameters on the bridge response is more significant than that of site parameters. The site effect leads to the difference of the mean values of curvature ductility ratios of two main piers in longitudinal and transverse directions to be 85% and 88%. There are differences in the sensitivities of the main piers and bearings to each parameter. When the dip angle of the fault is between 33°~60°，the seismic response of the bridge shows a trend of increasing first and then decreasing，and the curvature ductility ratio of the main pier can differ by 35%. The water layer has an inhibitory effect on ground motions； however，the amplification effect of hydrodynamic pressures on the seismic response of the bridge is more prominent.

To study the influence of different degrees of steel corrosion and axial compression ratio on the seismic performance of corroded L-shaped reinforced concrete （RC） shear walls，the test specimens of 5 L-shaped RC shear walls with a shear-to-span ratio of 2.5 were subjected to accelerated corrosion by using dry-wet cycle and external current corrosion method，then the specimens were subjected to a pseudo-static test. The test results show that with the increase of corrosion degree，the bearing capacity of the specimens gradually decreased，and the decrease rate of positive （flange tension） bearing capacity was higher than that of the negative （flange compression）. The specimen deformation and energy dissipation capacity deteriorated to varying degrees，the stiffness degradation aggravated，and the percentage of shear deformation in the positive peak point increased. When the degree of corrosion was equal，with the increase of the axial compression ratio，the positive failure mode of the corroded specimen developed into small eccentric failure progressively. In the meantime，the positive bearing capacity of the specimens first increased and then decreased，while the negative bearing capacity of the test specimens gradually increased，and the increase rate of the negative bearing capacity was greater than that of the positive； the deformation capacity of the specimens constantly decreased，and the decrease rate of the positive deformation capacity was greater than that of the negative； the energy dissipation capacity，shear deformation and percentage of shear deformation of the specimens all decreased continuously.

The vibration reduction characteristic of rotor system with active elastic support dry friction damper is studied in this paper. The dynamic model of rotor system is established and a 2D friction model of contact surface in dry friction damper us built. The transient and steady state dynamic responses of rotor system are obtained after dynamic equations being solved by utilizing Newmark-HHT numerical integration method. The steady state vibration signals of dry friction damper rotor system under different normal load are compared，meanwhile the transient dynamic responses of rotor system before and after turning on dry friction damper are studied. Experimental test rig for rotor system and dry friction damper are set up. The vibration signals of rotor while passing the first-second critical speed regions are measured and analyzed. Then the experimental vibration signals are compared with simulation vibration responses to verify the vibration reduction effect，and the vibration attenuation characteristic of dry friction damper on rotor system under different working conditions is studied. The results show that the active elastic support dry friction damper could only attenuate rotor’s vibration within a certain normal force. Finally，the results could provide theoretical guide for vibration control strategy on rotor system.

Steel spring floating slab tracks are equipped to reduce the vibration impact on precision instruments along the metro lines，but the ground vibration would be amplified at the natural frequency of the tracks. In order to address the negative impact of natural frequency vibration amplification on the surrounding environment of floating slab track，a full frequency control method considering frequency matching for environmental vibration in collaboration with metro vibration sources and propagation paths is proposed，which is based on the theory of periodic structure bandgap structure. The effectiveness of this method is analyzed by establishing a three-dimensional metro train-floating slab track coupling model and a finite element analysis model of track bed-tunnel- soil-row piles. The research results show that the ground vibration can be reduced about 4~7 dB at the natural frequency of the floating slab track plate by adjusting the band gap range of periodic pile to 7~9 Hz，eliminating the adverse effect of vibration amplification at the natural frequency of the track. Compared to ordinary tracks，the environmental vibration comprehensive control method proposed in this article has good vibration control effects and can effectively reduce the vibration level of sensitive points on the ground in the full frequency range.

Based on the train-track coupling dynamics and probability density evolution theory，a random vibration model of train-track system considering both the crosswind and track irregularity is established. The N-dimensional hypercube point set is used to generate the discrete random frequency and phase representative point set. Based on the random harmonic function method and the harmonic superposition method，the random track irregularity excitation samples and the wind speed time-history samples are simulated respectively. The obtained two random excitations are introduced into the train-track coupling system to obtain the representative responses. The probability density evolution equation of representative response is solved using the bilateral difference method to obtain the time-varying probability density evolution distribution of the vibration response. The Monte Carlo method （MCM） is employed to verify the computational efficiency and accuracy of the proposed model. The results indicate that the probability density evolution method （PDEM） is appliable to the random analysis of vehicle-track system under double random excitations including crosswind and track irregularity. When the number of representative sample points is 300 and the screening radius is 17.7，a good calculation results can be obtained by the proposed model in this paper. The random response analysis regarding a single random input cannot express an accurate result of the vehicle-track system’s random dynamic characteristic，which indicates the required consideration of both random excitations of crosswind and track irregularity in the random vibration analysis of vehicle-track system.

The fifth generation “seismic ground motion parameters zonation map of China” （GB 18306―2015），which was promulgated and implemented in China，introduced the vary rare earthquake effect for the first time. However，the current seismic design specifications still adopt the three-level defense principle. The seismic design for vary rare earthquake has become one of the urgent issues that need to be addressed in structural seismic design. Based on the identification method of continuous wavelet transform，this paper selects 12 pulse-like ground motions and 12 non-pulse seismic motions recorded in the Turkey mega earthquake on February 6，2023. The incremental dynamic analysis （IDA） is conducted on continuous pipelines and ductile iron pipelines to evaluate their seismic fragility. The fragility analysis results are compared with the failure probability obtained by empirical statistical method. The results show that the effect of pulse-like ground motions significantly increases the probability of serious structural damage for buried pipelines with different forms. Compared with continuous pipelines，ductile iron pipelines are more prone to damage underground motions，and are more sensitive to the pulse-like ground motion. The empirical statistical results based on actual seismic damage data are slightly lower than the failure probability of pipelines under non-pulse earthquake motion，but significantly underestimate the damage of buried pipelines under pulse earthquake motion. In this paper，the failure probability of different types of buried pipelines under pulse-like seismic motions is given，and the research results can provide a strong theoretical basis for the risk assessment and seismic design of buried pipelines under very rare and pulse-like ground motions.

Based on the flow simulations through delayed detached-eddy simulation model，the methods of sparsity-promoting dynamic mode decomposition and spectral proper orthogonal decomposition are applied for analysing the mode decomposition on the wake flow. Then combined by the acoustic analogy approach，this study investigates the behaviour of flow and aerodynamic noise generated around tandem seal-vibrissa-shaped cylinder in comparison with the cases of tandem cylinderlike and elliptical bars with the same characteristic length corresponding to the cylinder diameter of 30 mm for a range of Reynolds numbers （Re=6×10⁴~1.2×10⁵）. Results show that the lift fluctuations of the downstream bars are stronger than those of the upstream bars and the downstream bars dominate the aerodynamic noise radiation. The alternative arrangement of the saddle and nodal planes of seal-vibrissa-shaped cylinder introduces three-dimensional flow separations and suppresses the shear layer interactions，improving greatly the flow stability. The structure destroys the regular vortex shedding of Karman vortex street occurring in tandem cylinder wake. The presence of reverse vortex shedding generated by two adjacent saddle surfaces in the flow of tandem seal-vibrissa-shaped cylinder makes the lateral force balanced partially and reduces significantly the lift fluctuations as well as the vortex-induced vibration. The aerodynamic noise generated by the non-constant fluctuating force exerted on the wall surfaces of bars are suppressed effectively. The sound pressure level is reduced at most frequencies. Thereby the tandem seal-vibrissa-shaped cylinder is demonstrated to have a significant noise reduction effect. The experimental measurements verify the accuracy of the aerodynamic noise predictions. The current work would provide a certain scientific research and engineering application value for the aerodynamic noise control on cylinderlike bars.