Advanced Materials Research Vols. 538-541

Abstract: Pointed to character of rheological mechanics and limited equilibrium method, a new viso-elasto-plastic rheological model is builded with minimum locked load formula abtained.The finite difference method with C++ and inline FISH program ,is applied to analyze engineering instance. Based on calculated results and testing on spot, plentiful key parameters on whole bonged and prestressed bolt is studied.Lastly,the conclusions are open out ,including minimum locked loading,stress and maximal axial distribution of prestressed steal, hump distribution of shear stress on grount,shear strain rate of surface and displacement of reinforced foundation pit and so on.The numerical calculation is coincident with testing factors.

Abstract: As the development and applying of real-time multimedia such as VoIP, video conferencing and so on, the Internet is required to provide a better QoS support. However, current IP network can only provide ‘Best Effort’ service and can not satisfy different network multimedia traffic quality requirements. Based on the analysis DiffServ architecture and studies its control mechanism, the OPNET simulation design different ToS value in IP header of VoIP traffic, and apply WFQ scheduling algorithm on the bottleneck link. The simulation results compare jitter, delay, delay variation of different ToS value of VoIP traffic, and analyze relationship of QoS and ToS value in the IP network.

Abstract: This paper describes the methods of Harmonic Elimination, with the development of power electronic equipment, harmonic pollution of power system is more and more serious traditional method for harmonic elimination and reactive power compensation is the LC power filter based on resonance principle, but this method can only eliminate the specified order harmonic, and probably cause parallel or series resonance with the power system. Due to the high controlling and quick response, active power filter has been paid more attention for eliminating harmonic with magnitude and phase varying. This paper discusses the main approaches for harmonic damping, proposes the study development of active power filter(APF), and gives some forecasting on the research of active power filter and hybrid active power filter.

Abstract: Ship host is the heart of one ship, while the crankshaft is the core components of ship host. Created a three-dimension crankshaft’s modal through UG, then use FEM software ANSYS to simplified the characteristics details and constraints. Take the modal analysis of the crankshaft in order to gain the natural frequency and mode shapes).

Abstract: Loading and solving the whole converter model in its three working positions based on ANSYS Workbench, getting the rods’ stress distribution, then finding out the value and position of the maximum stress, finally, checking the static strength. The results show that all rods can meet the strength requirements.

Abstract: Taking the G4-73№8D centrifugal fan as research object and utilizing the software of NUMECA to simulate flow fields of volute with different widths, the parameters of width are optimized through contrastive analysis of the effects on internal flow characteristics and performance. Results show that the optimized scheme can improve the uniformity of internal flow field, full pressure and efficiency seperatly increase by 0.52% and 0.48% under the design flow. For the needs of variable fan load operation, this paper puts forward the optimization principle of width parameter.

Abstract: The dynamic calibration of artillery chamber pressure testing system under simulating application environment is an important means to ensure the measurement accuracy. Dynamic calibration device can simulate the testing environment with high temperature and high pressure in the artillery chamber. The main body of the calibration device is the key part to withstand instant high temperature and high pressure. In the paper, the structure strength of the main boy of the calibration device is theoretically analyzed and systematically calculated, and the stress of it is calculated by the finite element software. Simulation and analytical results indicate that the main boy of the device can withstand pressure of up to 8000bar. Finally, it is verified by the experiment and the results that the structural strength is accord with the design.

Abstract: Shaft seal lubricating oil leakage of the J-201 Butadiene Gas Twin-screw Compressor occurs from time to time. According to the characteristics and related theories of process medium, the mechanical seal structure and pattern of Twin-screw Compressor had improved design . Using the existing auxiliary system and keeping the existing sealing structure, the non-contact mechanical sealing of process mediumprocess mediumdouble reverse crossing-groove oil film has ‘self-cleaning function’ which was applied to the screw compressor. To analysis its application technology and performance, the problem of Butadiene Gas Twin-screw Compressor shaft seal leakage had been solved.

Abstract: This paper put forward a kind of crank-group driving mechanism on the basis of parallelogram mechanism , introduced its concept, design process, and analyzed the feasibility of its movement. It can drive multiple parallel-axis synchronously, and it is a new way of transmission.

Abstract: Many tunnels were subjected earthquake. According to the damaged features of tunnels in earthquakes indoorsand outdoors, the macroscopic damage of tunnels are summarized. On the base of the damage manifestation, the failure mechanism of tunnel damage is preliminarily analyzed. Comparison with the failure mode on the shaking table model test has been made, and some suggestion of on the weak links at the tunnel entrance, faults and shallow buried section for designers has been put forward.