Under the action of shock wave due to non-contact underwater explosion, ships with small size or large stiffness will have the response of large rigid-body motion. Based on Taylor plate equation, and taking the additional mass of transverse motion into account, the kinematic equations of 2D cross-section under the shock wave action due to the non-contact underwater explosion were established. And the response of the rigid body motion of a ship to the explosion was calculated. The results are in good agreement with the experimental data, which shows that the present method can be applied in prediction of motion response of ships under shock wave action.

The anti-shock capability of marine equipment is measured by shock limited load, which is the important content of marine anti-shock research. The shock limited load can be used to select equipments and to design vibration isolation system. Shock limited load is the inherence characteristic of equipment. Input acceleration or shock spectrum is used to measure the shock limited load. The shock failure rule of marine diesel engine includes stress limit, strain limit, displacement limit and failure of connecting structures. Shock response simulation analysis of TBD234V6 diesel engine was done in this paper. It was found that under the shock load prescribed by BV043/85 standard, the stress exceeds the limitation value in the stop condition. The relative deformation between two parts can reach one or two millimeters, which indicates that the parts in assembling should avoid interference from the others. Specially, the deformation of crankshaft showed that the oil film is destroyed. Thus, the engine should be isolated. The shock response of the bolted joints of the engine base was calculated. The results indicated that the bolted joints are separated.

According to the characteristics of shock resistance computation for pipeline system, a simple method based on beam theory was presented. It was found that the computational result is in good accordance with that from the finite element simulation. Thus, this method provides a good reference for shock resistance design of the pipeline systems.

The dynamic crush behavior of an anti-shock layer with elastic foundation was investigated. Considering the hyperelastic and viscoelastic behavior of the material, the shock resistance capacity of the anti-shock layer was analyzed. Influence of the structure parameters, such as relative density, edge length and topological shape, on the anti-shock performance of the layer was studied. It was found that in low frequency range the shock spectrum is lower when the relative density and the edge length of the layer are smaller, and round hole is the best choice for the anti-shock layer. While in high and middle frequency range, the anti-symmetric honeycomb structures have the best dynamic performance. On the base of the analysis, the optimization design, called anti-shock double-layer structure, has been provided, which has excellent dynamic performance compared to the traditional anti-shock layer.

In modern naval wars, the ships may be attacked by air or underwater explosive weapons, which not only damage the ship structures, instruments and weapon systems, but also seriously injure the crew on shipboard. In this paper, the refined description, comparison and analysis on ship shock injury, air shock injury and underwater shock injury were given respectively in several aspects, including shock wave characters, injury mechanisms, injury symptoms, safety limits and protection measures. Results of the research will be helpful to precisely and fast diagnose and cure the wounded, as well as offer a reference for anti-shock protection research.

For the purpose of noise control, the sources and mechanism of the HVAC (Heating Ventilation and Air Conditioning) system noise on offshore platform were analyzed. It is shown that besides the HVAC system noise there are ambient noise and the secondary noise radiated by piping system, and based on the theory of noise control, the measures of noise reduction were proposed. Results of this research provide some reference for noise control of offshore platform HVAC system, and also have a guiding significance for HVAC system design in the field of marine engineering.

To study the problem of noise radiation penetrating ship’s hull plate, a hybrid method for analyzing medium-frequency vibration of a model structure was established. Statistical energy analysis and finite element method based on wave propagation theory were applied. The reciprocity principle for diffusion field of multi-degree of freedom was subsequently employed to yield a new method which realized the coupling calculation between deterministic components and statistical components. Then the vibration-acoustic response of the model structure was obtained. Transmission loss of the plate structure was calculated. Through the comparison with the results from traditional SEA method and mass law curve, the effectiveness and accuracy of the current method was validated.

Vibration and noise of scroll compressors of air conditioning units at the top floor of an office building in an Economic and Technological Development Zone are excessively high. The noise and vibration of the units have severe impact on the downstairs offices. Through the testing of these units, it is found that the central air conditioning unit and its pipes have no vibration isolators at all, which form an acoustic bridge between the equipment and the building and cause the spread of solid sound. Therefore, vibration isolation must be considered according to the characteristic of the solid sound spread to effectively reduce the pollution of low frequency noise. Due to the actual situation of the top floor, a double-stage vibration isolation system is considered. With the calculation, the vibration isolation system is designed, and then it is made and installed to the equipment. Finally, a good isolation effect is obtained. The average value of the noise level is reduced by 20 dB.

The time-varying weighted combination forecast based on polynomial approximation formulas of unary and binary functions is proposed and used to model and forecast the structural response time-series of some aircrafts. Taking the unbiasedness and nonnegativity constraints into consideration, the relaxation variables are introduced to transform the inequality constraint to equality constraint, and the new objective function of the combination forecast is constructed based on penalty function. The Gene Algorithm is used to acquire the numerical solution of all variables and the function of time-varying weights. The application results verify the efficiency of this method.

Magnetorheological (MR) elastomer is a new MR material, whose rheological characteristics are controllable and invertible. It has the advantage of very fast response and low energy consuming, and becomes more and more attractive because of its wide prosperity in engineering application. Based on current research, some problems in MR elastomer isolator’s design, such as the method of developing practical MR elastomers, the material and design of magnetic circuit, etc., are systematically studied. Some important issues are put forward for further study.

The relation between train door’s modes and transient pressure wave for high-speed train’s crossing is discussed. The basic theory on mode test is introduced. The basic mode of a single train’s door was obtained by hammering-impulse excitation. The developing mode of train’s door-frame system was obtained by sinusoidal frequency-scanning excitation. Combining the basic mode and the developing mode of the train’s door, its frequencies and modes of bending and torsional vibrations can be understood. With the improvement of the mode’s parameters of the train’s door, the effect of transient pressure wave in the high-speed train’s crossing can be reduced and relaxed.

To investigate the dynamic transmission mechanism and control strategy of the flexible isolation system from the viewpoint of power flow is a hot topic in the field of vibration and noise control. Due to the interaction and similarity between mechanical and electrical disciplines, the Thevenin equivalent method in circuit analysis is applied to the power flow calculation in the vibration isolation system. The transmission of power flow in each coupling interface is calculated and the power flow transmission characteristic is analyzed. Program is written by means of the Matlab code for numerical simulation. The response of the system and the power flow transmissibility are simulated, and the vibration isolation system’s acceleration curve is plotted. The influence of structural parameters on power flow is systemically studied. The effects of the single-stage and multi-stage vibration isolation systems are compared.

Radiation noise from machinery equipment through the pipe system is one of the most important noise sources of submarines. As the extensive applications of floating rafts, the radiation noise from machinery equipment through foundation has already been well controlled. But radiation noise through pipe systems is becoming serious gradually now. The damping tape attached to the pipes surface can absorb vibration energy effectively. It is one of the effective means for reducing vibration and noise of the pipe systems. In this paper, the theoretical analysis and experimental study of the transmission loss of the damping tape are carried out. It is found that this method can effectively reduce the vibration and noise transmitted from the pipeline systems. Result of this research has significance for increasing the concealment of nuclear submarines.

Based on the working principle and the simplified model of MR damper, a series of experimental study on the damper force, energy dissipation and the response time under different excitation amplitude, frequency and control current is performed. The results indicate that the MR damper has a high effectiveness for energy dissipation, and the energy dissipation increases with the increasing of the excitation amplitude, frequency and control current. The response time of the MR damper does not change obviously with the control current changing, but decreases rapidly with the increase of vibration speed.

In this paper, the advantages of multistage pistontype MR damper are analyzed. The characteristics of the electromagnetic coils are systematically investigated. The simulation model for the MR damper is established and analyzed by means of the finite element software of Maxwell. From the model analysis, it is shown that to raise the utilization rate of the magnetic circuit, the electromagnetic coils in the damper should be connected in parallel form and conducted with inverse current. In order to improve the distribution of magnetic flux and guarantee the uniform distribution of magnetic induction in the dampers gap, the effective length in the magnetic circuit should be adjusted and trapezoidal shaped section for the piston alveolar should be adopted.

A new method of fault diagnosis of in-situ sampled vibration signals is introduced for the non-stationery signals of rotating machines by using the harmonic wavelet filtering. Based on the nice box-shaped characteristic of spectrum of harmonic wavelet, the components in prescribed frequency region and other frequency components are decomposed to independent frequency bands without any overlapping or leaking. Then the frequency components in the prescribed region can be extracted by data reconstruction. Simulation results and practical examples show that this method has good filtering effect. It can extract the valuable frequency components for elementary fault diagnosis. This method has the merits of simple algorithm and computer-time saving.

Cantilever rotor is the key component part of mechanical equipment. Based on the failure mode of dynamic response of the cantilever rotor, the ensitivity factors which affect structure reliability, such as load, size of structure, properties of materials, are analyzed. The utmost equations of the cantilever rotor in both static and dynamic states are built. Each equation is linearized at the average point by Taylor Expansion scheme. The reliability of structure is calculated by employing the theory of the primary second moment. The reliability results of considering and ignoring the inertial force respectively are compared mutually and analyzed. Then, an effective reliability analysis method for cantilever rotor is established.

The nonlinear dynamic behavior of the slideway-joint system of machine tools is studied. Taking into account the hysteretic characteristics of this system in contact vibration, a mathematical model for dynamic analysis is established. By means of asymptotic method, the coefficients of damping and stiffness equivalent to the hysteresis are obtained. Range-Kutta method is used to solve the system equation. The nonlinear dynamic responses of the guideway-joint system for different damping coefficients are discussed. The result shows that the chaotic vibration will occur when the damping oefficient varies in some range.