Advanced Materials Research Vols. 834-836

Abstract: An analysis based on the first kind of Lagranges equations was presented for investigating the vibration and acoustic radiation of underwater finite cylindrical shell with interior plate under multiple excitations. The strain energy and kinetic energy of cylinder and plate were gained by the theory of plates and shells, and the potential energy of excitation and fluid loading was found based on acoustic-vibration coupling, and the connection conditions of plate and cylinder were expressed by Lagrange multipliers, then the vibro-acoustic equations of finite cylinder with interior plate under shafting excitation were established. The influences of excitations and plates position to the vibro-acoustic characteristics were studied by the equations. The results show that the frequency components of plate-shell structure are more complex. For the double excitations on plate, the distance between excitations is larger, the average velocity and sound radiation power are lower, while the radiation efficiency is larger. The modeling and analytical methods adopted in this paper are also available for more complex composite structure.

Abstract: .Grinding wheel as the research object in this paper and aim at the vibration signal use the weight balance principle to balance the centrifugal force caused by the eccentric whee. Designed a kind of self-optimization fuzzy controller, through online optimization correction factor realized the control rules of self-adjustment and self-improvement. Not only solved the problem of relying on the Precise mathematical mode as the conventional control system,but also make the control system has automatic adaptation for the changes of the object properties.Experimental results show that:the effect of the correct balance amount and the grinding wheel unbalance correction offset is good, the vibration drop rate reached 93.2%, has played a good role in inhibition of unbalance, the grinder vibration quantity significantly reduced and improved the performance of the control system.

Abstract: At present, the bud type rings are widely used in the hydraulic cylinder piston rod seal, but there is no corresponding detection method to measure the contact stress when the seals are in the dynamic sealing condition. However, the contact stress is very important for analyzing the performance of the seals. A method for measuring the contact stress is presented in this paper, and the design of major parts of the test cylinder and the selection of seals are emphatically introduced.

Abstract: The reason about the scour of the submarine pipeline is researched in this paper. Through the mechanical analysis about the sand grain in the downstream of the pipe, the critical condition about of scour start is derived. The balance condition about the scour is studied. Through the mechanical analysis about the sand grain in the scour hole, the maximal scour hole depth is got.

Abstract: A slide-style 6-8 multianvil high pressure apparatus which has a better synchronicity and smaller step difference uncertainty has been developed in recent years. The second-stage pressure-generating system was established successfully. The cell pressures for 18/8, 14/8, 12/6, 10/4, 8/3 assemblies have been calibrated by using fixed point method at room temperature. The 8/3 assembly has an excellent pressure efficiency and could be obtained 22.5GPa with only 250 ton loading force. The size of gaskets and performance of transmitting medium have a great influence on cell pressure. Semi-sintered MgO (porosity 40%) medium is more excellent than pyrophyllite in performance of transmitting pressure.

Abstract: Integrating spectrum and navigation technology is an impotant research field. Using air-ground position model for earth observation is a hot topic in the field of photogrammetry and remote-sensing. When in the absence of ground control points or only a small amount of ground control points, through the acquisition and display of images, data processing and analysis of a series of process, accurate navigation information for aircraft can be provided. In this paper a new method of multispectral navigationOtsu method is presented. Begin with the images of spectral features, the paper explored the method of the multispectral image navigation,using genetic algorithms and realized the spectrum of aircraft navigation.

Abstract: The concept of arch longitudinal beam wharf was brought out in the contemporary shipping industry of China as a result of the conflict between traditional high-piled wharfs and the increasing size of freights. Different alignments of arch axis will lead to different internal force distributions and the most dangerous section. A series of equations for the arch axis are derived through the transformation of the exponential function under a 40-meter-long span. Based on the analysis of equations affected by the combined force of uniform load and concentrated load, it is providing reference for engineers and analysts with the internal force distribution under some commonly used axis and the location of the most dangerous section for the archs.

Abstract: As a new-type, high efficient hole-making technology, helical milling is widely used in making holes on composites and composite-metal compounds materials in the aircraft industry. In this paper, the problem of machining path optimization using helical milling is converted to a TSP (Traveling Salesman Problem), a mathematical model is established and solved using ACO (Ant Colony Optimization). Simulation results show that with the application of ACO, the traveling efficiency of helical milling has been increased by 41.1%.

Abstract: The stress singularities are obtained by two methods in elastic-viscoelastic joints, one is extending the corresponding solutions for elastic-elastic joints by using elastic-viscoelastic correspondence principles and the other is replacing the elastic material parameters with viscoelastic ones in Dundurs parameters directly. The difference between the two methods and the validity are discussed.

Abstract: Particle swarm optimization is simple, easily achieved and do not need to adjust many parameters. And it doesn't need the gradient information. Now, this algorithm has been widely used in function optimization, nerve network training, fuzzy systems control and so on. In this paper, we use this algorithm to solve the optimal design of thermal insulation on the pipeline. Numerical results show that this algrithm can get more precise results than methods before used.