Shell-feeding velocity is an important factor affecting naval gun shooting capacity. An agile shell-feeding system was designed to ensure quick implementation of the shell-feeding task. Based on composition of the agile shell-feeding system, hoist technology was studied. Working principles were discussed and the hydraulic pressure system of the hois was constructed. The hydraulic pressure cylinder and the accumulator were analyzed and calculated. Finally, PRO/E and ADAMS were used to simulate the hoist and its hydraulic system. It was found that this type of virtual prototype provides a good method to actualize a physical prototype.

Useful structure characteristics of elastic cylindrical shells have led them to being widely applied in virtual projects, so it is important to conduct vibration research on the shells and find it’s a simpler corresponding compact calculation method. Utilising the input and transfer point mobility of a thin plate structure, a theoretical expression of the cylindrical shell's bending vibration responsewas deduced and numerical simulations were done to simplify the theoretical expression within an acceptable error margin, greatly reducing the amount of computations. Furthermore, whole vibration response distributions of the cylindrical shell were analyzed. It was found thathe vibration energy propagates in helical form under mono-frequency excitation, while under bandwidth frequency excitation, it attenuates around in term of fluctuation. The axial attenuation rate of the vibration energy is larger than the circumferential attenuation rate.

To better guide the coating process of rectangular tiles on a ship hull, a computerized three-dimensional design method is proposed. Research was done on a tile generating algorithm, tile laying design flow, tiles gap examination algorithm, and tiles slight displacement, as well as cutting and rotating algorithms. A three-dimensional design system was developed using an MDT platform. The application of this system indicates that using the design arrangement to coat tiles on a ship's hull can result in enhanced coating quality.

The underwater target recognition is a key technology in acoustic confrontation and underwater defence. In this article, a recognition system based of fuzzy logic inference (FLI) is set up. This system is mainly composed of three parts: the fuzzy input module, the fuzzy logic inference module with a set of inference rules and the de-fuzzy output module. The inference result shows the recognition system is effective in most conditions.

Research was done to overcome traditional problems associated with automatic steering systems of a ship in a seaway. A ship's dynamic model with wave disturbances was built and a wave filter was designed by means of an extended states observer (ESO). The model estimated the low frequency motion component from a heading measurement corrupted by colorednoise, so back-and-forth steering caused by high frequency wave disturbances was avoided. At the same time, a robust autopilot system, designed by variable structure control theory, was presented. Simulation results achieved in dangerous sea status show that the wave filter works very well and the autopilot has strong robustness to environmental disturbances and model perturbation, and more importantly, the frequency of rudder adjustments is reduced noticeably.

The characteristics of a torpedo's acoustic homing trajectory with multiple targets were studied. The differential equations of torpedo motion were presented based on hydrodynamics. The Fourth order Runge-Kutta method was used to solve these equations. Derived from sonar equations and Snell’s law, a simple virtual underwater acoustic environment was established for simulating the torpedo homing process. The Newton iteration method was used to calculate homing range and ray tracing was approximated by piecewise line, which takes into consideration distortions cause by temperature, pressure, and salinity in a given sea area. The influence of some acoustic warfare equipment disturb the torpedo homing process in certain circumstances, including decoys and jammers, was alsotaken into account in simulations. Relative target identification logic and homing control laws were presented. Equal consideration during research was given to the requirements of real-timeactivity as well as accuracy. Finally, a practical torpedo homing trajectory simulation program was developed and applied to certain projects.

The factors that influence underwater vehicle sonar self-noise are analyzed, and genetic algorithms and a back propagation (BP) neural network are combined to predict underwater vehicle sonar self-noise. The experimental results demonstrate that underwater vehicle sonar self-noise can be predicted accurately by a GA-BP neural network that is based on actual underwater vehicle sonar data.

Fatigue failure has long been an important issue for ships and offshore structures. Among the numerous methods for predicting fatigue life, the spectral method is accepted as the most reliable. Although the theory behind spectral analysis is straight-forward, the analysis itself is complicated and time-consuming because it is closely related to critical technical details such as the application of fatigue loading (wave pressures and the inertial forces due to cargoes), the extraction of the strees, and the calculation of stress RAO. Here, four key technical details-loading application, displacement boundary condition, the calculation of stress RAO, and the extraction of the fatigue stress-are discussed thoroughly. For each aspect, a resolution is presented based on the finite element pre-and post-processing software MSC/PATRAN or FE solver MSC/NASTRAN. The resolutions are effective and efficient, which can help engineers perform spectral fatigue analysis accurately and faster.

A slender and flat shaft is a key part of the track recorder in marine vessels. However, the axial straightness of the shaft often exceeds standard measurements after it is machined. It has also been found that its precision does not last a long time. After thorough analysis of these problems the main reasons that affect machining quality are identified-and a process modification plan is put forward that meets design requirements of the shaft. The production and practice indicate that the precision of the shaft is stable for a long period and the quality of products improved substantially after new measures were employed, securing the e accuracy of the track recording of the marine vessel.

As the scale of complex system is growing larger and larger, interferences from internal and outer system can result in the collapse of one subsystem in a complex system. They will not only make one subsystem collapse but also influence the other subsystems. Moreover, the whole complex system can collapse consequently. The mechanism of collapse of complex system is due to the brittleness of complex system that is presented and argued as the basic characteristic in this paper. It is the brittleness link entropy between subsystems that leads to the collapse of whole system. Effective ways that can be adopted to reduce the brittleness entropy can see the successful control of brittleness.

Shell-feeding velocity is an important factor affecting naval gun shooting capacity. An agile shell-feeding system was designed to ensure quick implemention of the shell-feeding taks. Based on composition of the agile shell-feeding system, hoist technology was studied Working principles were discussed and the hydraulic pressure system of the hoist was constructed. The hydraulic pressure cylinder and the accumulator were analyzed and calculated. Finally, PRO/E and ADAMS were used to simulate the hoist and its hydraulic system. It was found that this type of virtual prototype a good method to actualize a physical prototype.

A type of poriferous TiO₂ material was prepared using cetyl trimethyl ammonium bromide as a template agent and butyl tetra titanate as a precursor. Through studying the photocatalytic kinetic activity of Rhodamine B photocatalytic degradation reaction with a UV-1601PC ultraviolet-visible spectrophotometer, the photocatalytic degradation process of Rhodamine B was found to not correspond to the first-order kinetic process completely. According to the reaction phenomenon, the photocatalytic degradation process of Rhodamine B with poriferous TiO₂ involved two irrevesible reactions. The kinetic model was tested using experimental data.

The coefficient and dynamics of water diffusion in adhesive-graphite joints were calculated insitu with energy dispersive X-ray (EDX) analysis, a method that is significantly simpler than elemental analysis. Water diffusion coefficient and dynamics of adhesive-graphite joints treated by different surface treatment menthods were also investigated. Calculation results indicated that the water diffusion rate in adhesive-graphite joints treated by sandpaper was higher than that treated by chemical oxidation or by silane couple agent. Also the durability of graphite joints treated by coupling agent is superior to that treated by chemical oxidation or sandpaper burnishing.