The variable-length dual-flexible manipulator is composed of a flexible joint and a flexible load，which is affected by flexibility，friction，and time variation of parameters. It will vibrate in the process of moving，which will reduce the tracking accuracy of the end-effector. In this paper，the fuzzy tuning PI control strategy based on disturbance observer is used to control the output speed of the dual-flexible manipulator servo system. The vibration of the manipulator can be suppressed indirectly by controlling the speed fluctuation of the flexible load. Based on the assumed modal method and the Lagrange principle，the dynamic equations of the dual-flexible manipulator are established. A low pass filter in the disturbance observer is designed according to the robust stability theorem，so that the disturbance observer can satisfy the stability of the controller parameter time-varying and the controlled object parameter perturbation jointly. The effectiveness of the proposed method is verified by numerical simulation and control experiments of the dual-flexible manipulator servo system. The experimental results show that the proposed control strategy can better eliminate the influence of parameter time-varying and flexibility on the output speed，and improve the control precision of the end-effector.

The one-dimensional and two-dimensional time-domain inversions of the bedrock incident waves cannot reflect the spatial arbitrariness of the incident azimuth and oblique incident angles，and the free field constructed based on these two methods might deviate is far from reality. It is necessary to carry out a three-dimensional time-domain inversion of the bedrock incident waves. Based on the wave function combination method，the free field of the ground surface control point is expressed by the time histories of the incident waves of P，SV and SH waves. A three-dimensional time-domain inversion method of bedrock incident waves based on design ground motions is established. Then，the spatially non-uniform free field under the oblique incidence of multi-wave combination is constructed. Finally，the free field deviations constructed based on one-dimensional and two-dimensional inversion methods are analyzed，and the influence mechanisms of different inversion and free field construction methods on the seismic response of the asphalt concrete core dam are revealed. The results show that the free field constructed based on the three-dimensional inversion method of ground motion has spatial inconsistency and can reflect the site ground motion field more comprehensively. Compared with the ground motion field constructed based on three-dimensional inversion，when the incident azimuth angle is 0°~60° and the oblique incident angle is 40°~90°，the feature point free field in the x-direction constructed by the one-dimensional inversion method has a large deviation with the maximum deviation55.8%； When the incident direction is parallel to a certain horizontal coordinate axis，the other horizontal free field deviation of the feature point constructed by the two-dimensional inversion is larger，and the maximum deviation is 100%； When the Poisson's ratio of the medium increases，the deviation of the x-direction free field decreases under the one-dimensional inversion，and the free-field deviation of the x-direction increases under the two-dimensional inversion，and the maximum deviations of the feature points are 46% and 36%，respectively. Compared with the maximum tensile stress of the core wall based on the three-dimensional inversion method of ground motion，the maximum tensile stresses under the two-dimensional and one-dimensional inversion methods are reduced by 83.3% and 20.0%，respectively. Therefore，it is necessary to perform a three-dimensional inversion of bedrock incident waves and construct a spatially non-uniform free field based on the design ground motion in the seismic design of dams.

With the rapid development of offshore wind power in recent years，the floating offshore wind turbine is proposed to capture more abundant and lasting wind energy in the deep sea，which has become the main direction of wind energy development. Due to the special structures and complex environment，the accurate calculation and analysis of floating offshore wind turbines will be particularly important for a multi-body system. In this paper，the coupling dynamic model of a floating offshore wind turbine is deeply studied. The improved 14-DOF coupling dynamic model of spar floating offshore wind turbine under complex working conditions is established，including an aerodynamic model，hydrodynamic model and structural analysis model，which can accurately calculate its dynamic response and verified by numerical simulation. The main improvements are as follows： expanding its scope of application without using small approximation of the angle in the coordinate rotation matrix； considering the conversion relationship between angular velocity and Euler angular velocity，the motion equation of floating offshore wind turbine with wider application range and more accuracy is derived. Besides，considering the influence of fan blade torsion angle on blade deformation，the accurate in-plane and out-of-plane response of the blade is obtained. Meanwhile，the potential flow theory is used to calculate the hydrodynamic force in order to solve the limitations of the traditional Morison equation algorithm. The simulation analysis shows that the model proposed in this paper can calculate the dynamic response of floating offshore wind turbine system more accurately with wider applicability.

Considering the simply-supported cylindrical shells，the modal participation in dynamic responses is studied by considering the influence of sine and cosine modes，and a method for determining the order of modal truncation according to the distribution characteristics of modal participation factors is proposed. The dynamic responses of cylindrical shells under the impact excitation and rotating traveling wave excitation are obtained by the superposition of the sine and cosine modes，and the reliability of the determination method is verified by the convergence of responses. The results of theoretical calculations and finite element simulations show that the influence of sine and cosine modes must be considered simultaneously in calculation of the dynamic responses for cylindrical shells，which is different from the case of modal characteristics analysis. When cylindrical shells are subjected to impact excitation，the participation degree of each order sine and cosine modes is related to the location of the excitation point and observation point. When cylindrical shells are subjected to rotating traveling wave excitation，the participation degree of each order sine and cosine modes is closely related to the order and frequency of the excitation.

Aiming at the problem that the current traditional vibration sensor is limited by the installation and the number of measuring points when measuring the displacement of the rotating body，this paper uses a high-speed industrial camera as the acquisition medium，and collects the rotor vibration video on the rotor vibration test bench. The visual vibration measurement method tracks the full-field vibration displacement of multiple rotor targets. The feature pyramid network structure is introduced into the residual neural network，and the improved feature extraction backbone network is established by combining the attention mechanism. The identity re-identification method is used to strengthen the correlation of target displacement between adjacent frames，and to track the full-field vibration displacement signals of the rotator. Qualitative and quantitative comparisons of different network models on the rotor vibration displacement measurement dataset show that the network model proposed in this paper can obtain a tighter fit when the bounding box is regressed. The collected eddy current displacement signal is used as the standard value to compare the two rotor displacement signals，and the experimental results show that the waveform and spectral noise fitted by the multi-target tracking algorithm in this paper is the smallest and can match the eddy current signal. The experiments also prove the generalization performance of the algorithm in this paper，which reflects the engineering application value of visual measurement in the field of vibration displacement tracking of rotating bodies.