To address the issue of weak features related to faulty rotating parts in Instantaneous Angular Speed（IAS） signal，this study proposes a Average Down-Sampling Multi-Period Differential Means（ADSMPDM） scheme to enhance fault features. Firstly，based on the estimation characteristics of the IAS，the average down-sampling of the IAS signal is studied and its features of suppressing random noise are obtained. Secondly，the ADSMPDM scheme is proposed to enhance the features related to the fault in the IAS signal based on the advantages of the average down-sampling （such as noise suppression，low computational cost and low storage space） and accumulative characteristic of multi-period differential means. Finally，the features related to the fault are revealed by order spectrum analysis. By using Simulations and experiments and comparing with fast kurtogram，multipoint optimal minimum entropy deconvolution adjusted，discrete random separation and spectral amplitude modulation，the effectiveness and advantages of the ADSMPDM algorithm in enhancing gear and bearing fault feature components are verified.

Recursive Least Squares algorithm is widely adopted in the field of micro-vibration adaptive control because of its simplicity and speed. Due to the particularity and complexity of the disturbance environment in the micro-vibration active control application，the robustness of the parameter adaptive algorithm used in the micro-vibration control needs to be considered. For the Multiple-Input Multiple-Output （MIMO） active vibration control system，this paper presents a MIMO robust parameter adaptive algorithm based on an Infinite Impulse Response （IIR） filter. This robust parameter adaptive algorithm takes advantage of the dead zone and normalization. The deducing process and convergence analysis of the robust parameter adaptive algorithm are illustrated in detail. A 3-DOF real time micro-vibration control experimental platform has been constructed. Comparison are provided with sine disturbance，double sine disturbance and broadband disturbance. Experimental results confirm the feasibility and robust of the proposed algorithm.

Through shear tests on small lead-core rubber bearings，the effects of bearing shear strain，compressive stress and loading frequency on the bearing's equivalent horizontal stiffness，post-yield stiffness，yield force and equivalent damping ratio are studied. The results show that： With the increase of shear strain，the equivalent horizontal stiffness and the post-yield stiffness of the bearing decrease，the yield force increases，and the equivalent damping ratio decreases linearly； with the increase of the vertical compressive stress，the equal the effective horizontal stiffness decreases，the stiffness decreases linearly after yielding，and the yield force and the equivalent damping ratio increase linearly； the loading frequency has basically no effect on the shear performance of the bearing and can be ignored； within 100% of the shear strain，apply the shear strain and compressive stress did not cause damage to the isolation bearing； large deformation and large compressive stress above 100% shear strain will cause the bearing to enter into plastic，causing partial permanent damage to the bearing. Suggestions that the working conditions need to be designed according to the actual needs of the shaking table test are put forward. The correction coefficient of the Japanese code equivalent horizontal stiffness calculation formula is proposed，which is compared with the measured value of the shaking table test to improve the accuracy.

Reaction wheels are not only important attitude control actuators for satellites，but also the most prominent onboard micro-vibration source. Considering the varying rotating speed of reaction wheels，this paper proposes a new vibration isolation method using a six-strut isolator combined with the electromagnetic shunt damping （EMSD） technique. A dynamic model of the coupled system consists of a reaction wheel and the isolator is derived including the gyroscopic effect produced by the rotating wheel. The results obtained through analytical analysis and simulations show that gyroscopic effects have a great effect on the natural modes，frequencies，and isolation performance. And then，the influences of key parameters on the isolation performance are analyzed and optimized. Finally，an isolation strut based on the EMSD technique is manufactured and tested. The experiment results verified the influences of the stiffness and EMSD on the transmissibility of the strut.

Medium and small span bridges make up a large proportion of highway bridges in China. Due to harsh service conditions，the expansion joints are prone to diseases，which can exacerbate vehicle vibrations，and subsequently lead to the damage of the end bearings and other components. In order to study the influence of expansion joint and bearing parameters on the vehicle-induced dynamic response of simply supported beam bridge，this paper establishes a numerical analysis method of vehicle-expansion joint-bridge coupling dynamic response （VBCV-J）. The effectiveness of VBCV-J analysis method is verified using measured data，followed by an investigation the influence of expansion joint and support parameters. The results show that： The speed is closely related to vehicle vibration. When the vehicle speed is high and the Road Surface Condition （RSC） is “normal”，the impact effect of vehicles on expansion joints and the ends of beams can exceed the specified values.. If the girder in the expansion joint is higher than the pavement，the impact on the expansion joint will significantly increase，conversely，it will decrease. When the girder in the expansion joint is higher or lower than the road surface，the impact at the end of the main beam will increase. A reduction in the support stiffness of the expansion joint or a void in the side support of the main beam will significantly increase the impact effect on both the expansion joint and the end of the main beam. A decrease in the stiffness of the main beam support primarily results in an increased impact on the entire main beam. Damage to the expansion joints not only affects their own impact，but also greatly increases the impact on the end members of the simply supported beams. During design and maintenance，sufficient attention should be given to the end members of the beams.

An efficient and accurate evaluation of the seismic performance of long-span continuous rigid frame bridges using a simplified method is essential in the design and strengthening of such bridges. As a simplified method to evaluate the seismic performance of bridges，the endurance time method can be used to simulate the whole process of bridge from intact to collapse with nonlinear time history analysis only once. In order to study the applicability and accuracy of the endurance time method in evaluating the longitudinal seismic performance of continuous rigid frame，this paper investigated a long-span continuous rigid frame bridge with corrugated steel webs. Three acceleration time-history curves were generated based on the design response spectrum of China highway bridge seismic code. In addition，16 natural ground motions were selected for incremental dynamic analysis. The seismic response characteristics of continuous rigid frame with corrugated steel webs were compared and studied. The seismic response characteristics of continuous rigid frame with corrugated steel webs were comparatively studied by endurance time analysis method and incremental dynamic analysis. Research results demonstrate that the endurance time analysis method results are within the envelope of the incremental dynamic analysis results. The time-history analysis results are within the envelope of the incremental dynamic analysis results. The median value of the endurance time analysis method has an allowable error with the mean curve of incremental dynamic analysis. Therefore，Endurance time analysis method can be used to evaluate seismic performance of the long-span continuous rigid frame bridge.

To address the low accuracy in diagnosing faults in wind turbine bearings caused by the different characteristic distribution of the source domain data and the target domain data，a fault transfer diagnosis method using improved residual neural networks is proposed. The convolution kernel and pooling kernel are set to a size suitable for the convolution operation of one-dimensional signals，allowing for direct extraction of fault features from the bearing vibration signals； Both batch normalization and case normalization are used in the one-dimensional residual network to further enhance the feature extraction ability of the model； In the model training stage，a new loss function is constructed based on the multiple kernel maximum mean discrepancy between the source domain data and the target domain data to improve the transfer learning and classification ability of the model. The effectiveness of the method is verified by conducting the experimental data of the faulty bearings. The results show that the proposed method can effectively extract the important features of bearing faults and achieve the transfer diagnosis and accurate classification of the bearing faults. This holds true even under varying speed operation conditions and when the bearing fault vibration signals are disturbed by some noise components. Therefore，this work provides a useful strategy in developing intelligent fault diagnosis technology of rotating machinery under complex working conditions.

In order to improve the application of the damping force of isolation device for free-standing objects，a new damping mechanism is developed. Its structure and working mechanism are expounded，and its mechanical characteristic is deduced and verified. Combined with the target performance of an isolation device for cultural relics，the parameters of the damping mechanism are designed by numerical method，and contrasted with the shaking table test. The results indicate that the damping mechanism has a simple structure and stable performance. The isolation device optimized by damping parameters achieves the set isolation target under the premise of meeting the displacement limit. The test results are highly consistent with the numerical analysis results，which not only prove the correctness of the damping design，but also verifies the installation quality and operation effect of the isolation device. In addition，the coincidence degree between two results can provide a new method for design comparison and quality evaluation of the isolation device，especially the coincidence degree of relative displacement curves.

The robust dynamic topology optimization of a continuum planar structure is studied to reduce its natural frequency variation when the structural material parameter uncertainties are considered. The uncertainties of the material properties are represented with the uncertain-but-bounded interval variables based on the non-probabilistic convex model. The dynamic topology optimization model for maximizing the first natural frequency is constituted by mitigating its variation，such that the robust optimization problem can be simply solved into a single-level framework. By the derivative analysis of the material parameters，a quadratic Taylor series expansion of the first natural frequency is obtained，and the design sensitivity of the natural frequency is accordingly evaluated in an explicit form under the uncertain material properties. By means of the material density-based strategy，the robust dynamic topology optimization is implemented with the material volume constraint，and the results are compared with those of the deterministic topology optimization. Optimal results show that the first-order natural frequency obtained with the proposed method has a higher robustness against the material property uncertainties，which fully demonstrates the importance of considering the uncertainties of the material parameters in the structural design stage.

The II-shaped composite girder is widely used in the construction of long-span cable-stayed bridges，but the weak vortex-induced vibration （VIV） performance of this type of section seriously limits its application prospects. A II-shaped composite girder double-tower cable-stayed bridge with a main span of 530 m is used as the engineering background，and the VIV performance and aerodynamic optimization measures of the II-shaped composite girder are studied by using wind tunnel tests. The tests show that the VIV of the original II-shaped section occurs at each wind attack angle，and the VIV amplitude of the girder can be reduced by setting guide vanes and the lower central stabilizer. The change in the inclination angle of guide vanes has a significant impact on the combined aerodynamic measure of VIV suppression performance. The combination measure VIV suppression performance with the guide vane of 30° inclination angle is the best，and the VIV can be significantly suppressed or even eliminated when the damping ratio required by the specification is 1.0%. The VIV suppression mechanism of the combined aerodynamic measure and the influence mechanism of the guide vane inclination angle change on the VIV suppression performance of the measure are studied by using computational fluid dynamics （CFD） numerical simulation. The calculation results show that the windward side guide vane in the 30° inclination guide vane combination measure can significantly improve the gas flow around the upstream section，and the cooperation with the lower central stabilizer can weaken the Karman vortex of the II-shaped section wake toy suppress the girder VIV. Changing the inclination angle of the guide vane not only affects the generation of vortices near the guide vane itself，but also affects the improvement of the lower central stabilizer on the vortex shedding state under the section，thereby significantly affecting the VIV suppression performance of the combined aerodynamic measure.