Base swing will bring additional gyroscopic moment and inertia load to the rotating machinery，affecting the vibration and stability of the rotor system and even endangering the rotor operation. In order to effectively control the vibration of the active magnetic bearing （AMB）-flexible rotor system under the base swing，a base acceleration feedforward algorithm is proposed in this paper. With the dynamic model and the parameters of the base swing，the optimal compensation current to suppress the vibration can be directly obtained by the proposed algorithm. Because of no iteration and simple structure，the algorithm has strong rapidity and practicality. Furtherly，to eliminate the influence of modeling error on the compensation performance，a method to correct compensating current is suggested. After that，the influence of the proposed algorithm on the rotor vibration in the spin speed range including the first bending critical speed is simulated. Finally，on the test platform，the effectiveness of the algorithm was verified when rotor in suspension without spin，constant speed and acceleration under the base swing. The theoretical and experimental results agree that the vibration perpendicular to the swing axis increases obviously due to the inertia load. The additional gyroscopic moment increases the vibration along the swing axis，and the rising amplitude grows along with the increase of the rotor spin speed. The algorithm proposed can efficiently suppress the rotor vibration under the base swing in the spin speed range including the first bending critical speed.

The magnetically suspended rotor applied to the moving carrier may be subject to the base motion excitation，causing the rotor vibration，and even cause friction and system instability. To explore the vibration response of the magnetically suspended rotor under the base excitation，the numerical simulation and experimental verification are conducted. The effect of the base excitation on the rotor is introduced into the differential equation of the rotor motion in the form of an additional generalized force. Considering the closed-loop control of the magnetic bearing，the dynamic model of the magnetically suspended rotor under base excitation is established. The influence of the excitation amplitude and frequency，the acceleration and shock width on the vibration response of the rotor is analyzed by numerical simulation. Finally，the base excitation experiments were conducted. The experimental results verify the accuracy of the magnetically suspended rotor model under the base excitation. The results show that the rotor vibration amplitude is proportional to the amplitude and square of frequency of the base harmonic excitation，the rotor vibration maximum is proportional to the base shock excitation acceleration. The proportional coefficient and differential coefficient of the magnetic bearing controller can suppress the rotor vibration brought by the base excitation.

A fast robust control strategy based on variable power log-reaching law is proposed for a class of manipulator systems with uncertain random oscillations in the mounting base. The uncertain dynamic model of the system is established based on Euler-Lagrange equation，and the oscillation term of the base in the model is regarded as the uncertain external disturbance force of the manipulator system. A new approach law of variable power logarithm function is proposed，which can realize the rapid approach of the system state far away from the sliding mode surface，and ensure the effective chattering suppression after approaching the sliding mode surface. On this basis，combined with a fast terminal sliding surface，a fast robust controller is designed，which can further improve the state convergence rate of the system. The finite-time convergence of the controller is proved based on Lyapunov stability theory. An experimental platform is built to further verify the effectiveness of the controller.

The large oscillation of the weight center on the sagittal plane can produce shock and oscillating force on the shoulders and back of the human body，which can cause muscle fatigue in the upper limbs. To alleviate the impact and oscillating force，a hip-joint driven backpack exoskeleton with adaptive adjustment of the weight-gravity center is proposed. Based on the five-bar model of the human body，the kinematic model of the gravity center in the human-weight system and the human-exoskeleton-weight system is established by the D-H method to analyze the trajectory of the gravity center. Based on the Newton-Euler method，the human dynamics model and the human-exoskeleton dynamics model are established. The changes in the human shoulder back forces and the lumbar，hip，and knee joint moments are obtained in the human-weight and human-exoskeleton-weight systems. Results are validated by the software OpenSim. Kinematics，dynamics，and software simulation show that the exoskeleton reduces the fluctuation of the gravity center，improves the torque distribution of each joint，and improves the load-bearing performance.

In this paper，the global dynamics of chaos and subharmonic bifurcation of an impacting system of cantilever beam supported by oblique springs under bilateral asymmetric rigid constraints are studied. It is difficult to study analytically the chaos and subharmonic bifurcation of the system because the stiffness term of the oblique spring support structure is a transcendental function. To do this，the stiffness term of the system is fitted by the approximation method，and the homoclinic orbit and its internal orbits of the approximate system are compared with the orbits of the original system. The threshold conditions for homoclinic chaos and subharmonic bifurcation are presented by applying the Melnikov method to the non-smooth impacting cantilever beam system. Moreover，the stability of the impacting subharmonic orbit is analyzed by combining characteristic multipliers of smooth manifolds with impact function，and the relationship between subharmonic bifurcation and chaos is analyzed. The effects of damping，excitation frequency，excitation amplitude and impact coefficient of restitution on chaos and subharmonic bifurcation are studied based on threshold conditions，which further verify the theoretical analysis.

In this paper，a method for calculating the vibration response of beams damped with constrained damping layer is presented. The indoor vibration experiment of I-beam was carried out，and the vibration response at different positions was measured. A numerical simulation model was established simultaneously based on the finite element method，and the natural frequencies and modal loss factors of I-beam were calculated accurately by using the modal strain energy method. Based on the above results，the modal superposition method was used for the harmonic response analysis，and the vibration response of the I-beam damped with constrained damping layer was obtained. The accuracy of the model was verified by comparing the measured and simulated results. The effects of design parameters （damping layer thickness and constrained layer thickness） on the natural frequency，modal loss factor and overall vibration acceleration level were analyzed. The results show that the vibration response of each component has a similar change rule. The overall vibration acceleration level of web is the largest，followed by the bottom，and the roof is the smallest. In general，the thickness of damping layer has little effect on the first 5 order natural frequencies of I-beam，but with the increase of the thickness of constrained layer，the first 5 order natural frequencies of I-beam decrease first and then increase. Increasing the thickness of damping layer and constrained layer can continuously improve the modal loss factor of I-beam，thereby reducing the overall vibration acceleration level effectively，and the vibration reduction effect of web is better than that of roof and bottom.

Based on the modified Timoshenko beam theory，the transverse vibration governing equation of the modified Timoshenko beam on the viscoelastic Pasternak foundation is established. The analytical solutions of the natural frequency and attenuation coefficient of the modified Timoshenko beam simply supported at both ends in the viscoelastic Pasternak foundation are derived with the reverberation-ray matrix method. The natural vibration characteristics of the modified Timoshenko beam on the viscoelastic Pasternak foundation under classical boundary conditions are calculated by dichotomy and golden section method. The effects of moment of inertia caused by shear deformation，beam length and different boundary conditions on the natural vibration characteristics of the structure are compared and analyzed. The results show that the natural frequency and attenuation coefficient of the modified Timoshenko beam on the viscoelastic Pasternak foundation are smaller than those of the classical Timoshenko beam； the shorter the beam，the more significant the influence of the moment of inertia caused by shear deformation on the natural frequency and attenuation coefficient of the structure，and the influence on the higher order is obviously greater than that on the low order； the stronger the boundary constraint condition，the more obvious the vibration energy attenuation.

The nonlinear dynamic systems exhibit particular behaviors when subjected to combined deterministic and stochastic excitation. A semi-analytical method for calculating the nonstationary response of a fractional nonlinear oscillator subjected to combined excitation is proposed. Representing the system response as a sum of a deterministic component and zero-mean stochastic component leads to two equivalent sub-equations for the differential equation of motion. The time-varying harmonic balance method is used for the nonstationary solution of the deterministic differential sub-equation，while the statistical linearization method is utilized for obtaining an equivalent linear substitution for the stochastic sub-equation. A semi-analytical solution of the equivalent linear equation is obtained by the Prony-SS and Laplace transform technique. The unknown deterministic/stochastic response components are obtained by solving the derived nonlinear algebraic equations simultaneously. Monte Carlo simulations demonstrate the applicability and accuracy of this method.

The advanced transfer path （ATPA） method is used to study the vibration transfer characteristics of the computer mainframe package from each cushion pad to key components under different vibration levels of random vibration through experiments，the analysis of the vibration contribution of the cushion pad and optimal design of vibration reduction are carried out. The results show that the measured vibration response of the two key components of the computer mainframe is consistent with the synthetic response of the ATPA method，which verifies the correctness of the ATPA theory for the analysis of the vibration transfer characteristics of the product packaging system； when the area of each cushion pad is the same， the two cushion pads on the same side of the key components of the computer mainframe play a decisive role in its acceleration response， thus being the key cushion pads； the cushion area of the key cushion pad affects the acceleration response PSD peak value and frequency range of the key components. With the increase of the cushion area，the acceleration response PSD peak value of key components gradually decreases； when the cushioning area of the key cushion pad is more than doubled，the reduction effect of the acceleration response PSD peak value tends to be saturated，the resonance peak becomes smooth，and the vibration response energy is dispersed over a wider frequency range. The vibration reduction optimized design keeps the non-key cushion pad unchanged and only increases the cushion area of the key cushion pad. The research results provide a reference for the vibration reduction design of the product.

In this paper，the characteristics of structural response and modal parameters of Shenzhen New World Center （height 238 m） are analyzed based on the field data during five typhoons in the last 10 years. The field results are further compared with the wind tunnel test results when the roughness exponent α is 0.22，0.30 and 0.35 respectively. The field results show that the building exhibits obvious crosswind vibration when reaching its maximum vibration amplitude，and the corresponding vibration is in the north-south direction. The measured maximum acceleration is 17.28 cm/s²，which meets the requirement of residential comfort. During the five typhoons，the modal frequencies are shown to be evidently amplitude dependent and time-varying，and it is more reasonable to describe the variation of modal frequency with time than the variation with amplitude. The modal frequency first decreases with time and reaches its minimum at the peak wind speed，and then returns to the normal value. The modal damping ratios tend to be scattered in the middle- and low-amplitude region，and rise slightly with increase in the amplitude. The maximum damping ratios in the alongwind and crosswind directions are 1.9% and 1.2%，respectively. The wind tunnel test results for α=0.35 are in good agreement with the field measured results，indicating that the wind tunnel test results for terrain category C are conservative.

Base-isolation system would undergo considerable great displacement subjected to strong earthquake. According to recent research progress，the hybrid control strategy combining variant tuned mass damper （VTMD） with base-isolation system has been proved to be effective in reducing such great displacement demand. However，large tuned mass is required to achieve better control performance，which may be difficult to realize in practical application. Employing the mass-amplification effect of the inerter device，a variant tuned mass damper inerter （VTMDI） is proposed in this study by inserting the inerter device in parallel with the dashpot in the VTMD and is attached to the isolation level in the base-isolated structure. Due to the stochastic nature of seismic ground motions，investigation into the optimum design of the VTMDI are conducted based on the framework of random vibration. It is demonstrated that the traditional optimization strategy，taking the inter-story drift of isolated superstructure as the optimization objective，is not cost-effective. Thereby，a novel optimization strategy consisting of two step optimization procedure is proposed. In this two-step optimization strategy，the optimization objective in the first step is taken as the control effect of the base-isolated structure equipped with the VTMDI compared with that of the corresponding base-isolated structure with the same dashpot，and then the optimization objective in the second step is to minimize the inter-story drift of isolated superstructure. And the dynamic time-history analyses show that both optimization strategies can effectively reduce the horizontal deformation in the isolation level and inter-story drift in the superstructure，and the excessive strokes of the tuned mass are also avoided. However，the two-step optimization strategy is more cost-effective than the traditional optimization strategy.

The traditional Tuned Mass Damper （TMD） has many issues，such as large additional mass requirement，limited installation space restrictions and large motion stroke required when the mass block vibrates. Based on the principle of translation-rotation mutual transformation and conservation of kinetic energy，the rotary inertia virtualizing translational mass based Tuned Mass Damper （RTMD） is proposed in this paper. The conceptual design of RTMD control system is carried out，and the motion equation of RTMD control system is established with the reference of a single degree of freedom system. The influence law of RTMD control system parameters on the vibration control effect of structure is analyzed. It is discovered that the control effect is closely related to the system’s physical mass ratio，inertial mass ratio，damping ratio，and such regulations can be applicable to general multiple degrees of freedom systems. The correctness of the design parameters of the RTMD control system and the realizability of the control system are verified by shaking table test of the design model. The results of time domain analysis and frequency domain analysis show that the dynamic response obtained from shaking table test is consistent with the dynamic response of numerical simulation，which verifies the correctness of the established theoretical equations of RTMD control system.

Seismic energy dissipation technology can significantly improve the seismic behavior of building structure. The effect of the damper depends on its effective connection with the main structure，there are few researches on the effective connection design method between the damper and the whole structure at present. In this paper，a cantilever wall structure with a new type of embedded parts is proposed for the intermediate column connection of metal dampers in engineering，and the design method and key points are given. In order to further explore the reliability of the design method and investigate the mechanical properties of the cantilever wall，two specimens were tested under quasi-static unidirectional loading and low-cycle reciprocating loading. The results show that the cantilever wall cracks begin to develop from the joint of embedded parts，and the stress in the corner and the core area of the embedded parts is larger when it is destroyed. Adding hidden beam and hidden column can better improve the load carrying capacity of the cantilever wall. The new embedded parts can be combined with the hidden beam and hidden column to make the cantilever wall bear larger damping force under the condition of small size，and ensure the damper to give full play to the seismic energy dissipation effect.

Considering the complexity of solving the seismic response of the energy-dissipated isolated structure with six-parameter viscoelastic damper under the excitation of Li Hongjing spectrum，a concise solution that can obtain random seismic response is proposed. The analysis model of six-parameter viscoelastic damper with support is adopted，and the mathematical modeling of energy dissipation and isolation structure with viscoelastic damper is realized by differential constitutive equation. Combined with complex mode method and the pseudo excitation method （PEM），the unified expression of frequency domain solution for system series response （displacement，velocity and damper force） of vibration isolation system is obtained. Taking Li Hongjing spectrum as the excitation power spectrum，the excitation power spectrum and the eigenvalue function of structural frequency response are simplified，and the concise analytical solutions of the system response power spectrum，response spectral moment and response variance under the random excitation are obtained. An example is given to verify the accuracy and efficiency of the proposed method in analyzing the dynamic response of the system compared with the traditional response analysis method such as the PEM，and the influence of different support stiffness on the vibration reduction effect of the damper is discussed.

In order to study the seismic effectiveness of the most commonly used support method for fixing figurine cultural relics，the full-scale shaking table tests of the seismic system （two types of figurine replicas with typical size and vulnerable materials and fixed measures of supports） were carried out. The seismic responses of the cultural relic replicas and the interaction between the cultural relic replicas and supports under different working conditions were obtained. The influence of the key body shape parameters of figurines，the clamping position of metal supports，the support size，the installation gap between cultural relic replicas and fixed measures on the movement state of cultural relics was discussed. The seismic effectiveness of support measures was evaluated and reasonable suggestions were put forward. It provided the necessary basis for the optimal design of fixed method for this type of cultural relics with the principle of safety and minimum intervention. The results showed that all the floating figurine replicas were overturned，which had a great risk of damage. The rocking responses of figurine replicas were effectively reduced after independent supports were used for fixation. As the ratio of the center of gravity height to the base width of the figurine replicas increases，along with the increase in their mass，the obvious plastic deformation or even the root fracture occurred in the case of smaller supports，resulting in overturning and damage of figurine replicas. At the same time，with the increase of the size of the supports，the improvement of the fixation effect was limited. Based on the principle of minimum intervention for cultural relics，and considering the seismic safety and the art exhibition，the support size should be optimized. The rocking responses of figurine were controlled to some extent when its shoulder was fixed by the support，however，with the increase of the fixed position，the sliding response of the figurine was more obvious. The surface of the figurine was easily damaged because of the interaction between the support and the figurine. When the gap between the two was filled with silica gel cushion，the rocking and sliding responses of figurine replicas were reduced by nearly 40% and 50% respectively，the strain at the root of the support was reduced by nearly 40%，and the strain at the contact area between the figurine and the support was reduced by nearly 60%，which effectively improved the seismic effectiveness of support measures.

In allusion to inadequate research on damage identification of multi-tiered reinforced soil retaining wall，a large shaking table test of two-tiered reinforced soil retaining wall was carried out. The time domain identification method was used to analyze the dynamic response characteristics of the model under horizontal seismic loading，and the distribution laws of the natural frequency and damping ratio of the upper and lower retaining walls were expounded. The corresponding relationship between the structural damage degree and the natural frequency and damping ratio was explored. The results show that the natural frequencies of the upper and lower retaining walls are basically the same before loading，and the damping ratio decreases with the increase of wall height. With the accumulation of loading conditions，the natural frequency gradually decreases and the damping ratio gradually increases. The distribution curves of natural frequency and damping ratio are fitted by polynomial method. The comparative analysis shows that when the natural frequency decreases by 0~15.41% and the damping ratio increases by 0~299.35%，the structure is basically intact. When the natural frequency decreases 15.41%~18.92% and the damping ratio increases 299.35%~360.07%，the structure is slight damage. When the natural frequency decreases by 18.92%~21.29% and the damping ratio increases by 360.07%~398.21%，the structure is in the middle damage stage； when the natural frequency decreases by 21.29%~29.60% and the damping ratio increases by 398.21%~532.99%，the structure is destroyed.

Aiming at the low accuracy of traditional empirical formulas in complex site environment，a predictive model for peak blasting vibration velocity based on grey wolf optimization support vector regression （PCA-GWO-SVR） with principal component analysis （PCA） feature selection is proposed. Based on the monitoring data of blasting excavation of dam abutment trough on the right bank of Baihetan Hydropower Station，the blasting center distance，maximum single-shot charge quantity，elevation difference，longitudinal wave velocity，bore spacing and bore row distance are selected as input parameters，and the characteristic values are selected by data dimension reduction of PCA，and the six selected features are dimensionally reduced to four characteristics with higher correlation. Support vector regression （SVR） is improved by grey wolf optimization algorithm （GWO） to obtain the optimal parameters. Parameters are input into the SVR model for evaluation. The research results show that the PCA-GWO-SVR algorithm has better agreement with the predicted values and the measured values of Sadowski formula，improved Sadowski formula，SVR，PCA-SVR，GWO-SVR. The predicted results are more accurate and can predict the peak value of blasting vibration of slope more effectively，which provides help for safety control of blasting construction of slope.

Large heavy-duty bearings have special working conditions. Under low speed conditions，the impact duration is prolonged，the system response amplitude is reduced，and the fault information is easier to be covered by noise. Acoustic emission technology has been widely used in the field of structural health monitoring and equipment condition detection because of its sensitivity to weak damage. The spatial localization method in acoustic emission technology can be used to accurately locate faults of large bearing with low speed and heavy load. The localization effect depends on the accurate arrival time of signals. The identification and accurate separation of each acoustic emission event is a major challenge at present. Gate recurrent unit network （GRU） can consider the internal in sequence data and extract temporal correlation features，which has certain advantages in signal processing. Akaike information criterion （AIC） can effectively identify two different stochastic processes. In this paper，an acoustic emission signal time of arrival picking method based on GRU and AIC is proposed. The results based on the lead and test data show that the proposed method has great potential in determining the large，heavy-duty，low-speed bearings acoustic emission signal arrival time by comparing with the traditional AIC，threshold discrimination and short term averaging/long term averaging.