Applied Mechanics and Materials Vols. 457-458

Abstract: The installation position of nozzle directly affect the efficiency of high pressure water jet cleaning. In order to improve the cleaning efficiency, the paper establish the three-dimensional structure and numerical model of the original nozzle assembly and the spiral nozzle assembly. The numerical simulation results show that, on the same boundary conditions, the effective hit range of the spiral nozzle assembly is greater and more uniform than that of the original nozzle assembly.The effective surge pressure of the spiral nozzle assembly is larger than that of the original nozzle assembly, spiral nozzle assembly can can reduce the blind cleaning area and improve the cleaning efficiency.

Abstract: The processing technology of machining deep hole in thin sheet is a kind of process using friction between driller and workpiece and plasticity of workpiece to form hole. The process is a kind of green mechanical processing technology. Studying green processing process in mechanical is becoming a development direction. In this paper, the new technological process to form deep hole on relative thin panel by friction heat not only saves material, but also saves man-hours, and the workpiece has a good piece of assembly. Because the processing technic is belong to local thermal processing, the diffusive wear and hardness of cemented carbide driller are studied by energy dispersive spectrum analysis energy dispersive spectrum analysis in this paper. The study results are useful to improve the life of driller and look for more appropriate machining parameters, and laid a foundation for further research on forming deep holes process on thin sheet metal by friction heat.

Abstract: Autofrettage process is now widely used to improve fatigue strength of high pressure components. This paper focuses on the fatigue life improvement of the high-pressure cylinder treated by autofrettage process. In this process, a high pressure cylinder treated by autofrettage process has been simulated by using FEA software, and surface variation of the cylinder has been analyzed. To further understand this process, theoretical fatigue analysis has also been carried out.

Abstract: The conductor is an important part of the process of power transmission. Keep conductor to be normal operation is an important link of power transmission. In practice, Due to the influence of many weather environments, such as wind, temperature, rain and snow, the conductor often appear ice disaster, dance and other disasters; therefore, the anti-vibration technology of conductor is an urgent need to develop. This paper masters the performance of damper by carrying out a great deal of performance test analysis, such as self-damping, the power of damper, anti-vibration effect. At the same time, this paper understands the effect of spacer arrangement on the sub span oscillation, through the finite element analysis and lingo program of nonlinear programming, laying the foundation for studying anti-vibration technology for large cross-section conductor.

Abstract: In order to improve the operating effect of the bio-electrodes implanted in the deep brain of the human for the treatment of the neurological disorders, the characteristics of cell tissue fluid in the energized condition was studied in this paper. According to the principle and the influential factor of the electrowetting, the Young-Lippmanns equation was improved and an experiment of the electrical induced tissue fluid process was carried out. The experimental results showed that the transformation of the tissue fluid shape before and after electricity was consistent with the electrowetting, and the cell tissue fluid electrowetting was existed indeed. The cell spreading power was changed and the area of the cell tissue fluid was increased, and it indicated that the electrowetting of the tissue fluid is useful to the growth of the cell.

Abstract: The supercharger technology of piston aviation engine determines its flight capabilities, and then establishes a turbocharger simulation model of an aviation piston engine. After simulating the engine ground features and 5000-meter altitude characteristics, and comparing the efficiency of compressor and turbocharger in different environments, after the installation of mechanical supercharger, gas flow has been improved, the cylinder pressure decreased about 10% compared with ground condition and engine altitude state power is restored, even 20,000 feet Power restored to 80%, which can meet the needs of high-altitude flight.

Abstract: In order to investigate the effect of suture density on the dynamic behavior of bioprosthetic heart valve, we establish the spherical leaflets models via computer aided design. Based on the parametric models of the heart valve, four kinds of suture density is analyzed and finite element analysis is used to simulate the mechanical performance of bioprosthetic heart valve. The results show that the stress distributions of the spherical valve leaflets with different suture density is quite different and the peak von-Mises with 50 suture points is lower than the other three kinds of suture density. From the whole loading process, we can find that the spherical valve leaflet with 50 suture points has better dynamic properties. This work is very helpful when manufacuturing the bioprosthetic heart valve，thus to prolong the lifetime of the bioprosthetic heart valve.

Abstract: Aluminum foams from A356 base alloy were produced by both the melt foaming process and gas injection foaming process. A comparison of microstructures between the two kinds of aluminum foams was carried out. The related causes were analyzed to form the difference in microstructure. Results indicate that aluminum foams produced by different processes are distinct in metallurgical structure. The average thickness of cell wall, the species and area fraction of secondary phases or particles and other metallurgical features have been all comparatively studied. The difference in microstructure features of the cell walls will also make the aluminum foams different in mechanical properties. Therefore, we need to select proper foaming process for aluminum foams according to the property requirements in practical application.

Abstract: By Changing the key points on the spiral curve, general groove geometry was determined. Considering the simplicity of modeling and analysis, cubic spline function was used to express the general groove profile. By using the boundary fitted coordinate system transformation, irregular computational domain was transferred to regular region; Based on flow conservation principle, finite volume method was applied to discrete compressible Reynolds equation; By the application of Newton-Raphson iteration method for solving algebraic equation, numerical model of general groove dry gas seals was established. When compared sample results with shallow groove theory, the capacity and stiffness of numerical results match well with theoretical ones, verifying the accuracy of novel numerical model. Through analysis of three typical groove seals, spiral groove seal has strongest carrying capacity. Pressure distribution of three groove seals subjects to the law of hydrodynamic pressure effect. And the numerical model established in this paper will offer a general calculate platform for optimization of groove geometry in the future.

Abstract: On the basis of the Preston assumption, the removal function of the annular polishing pad with the structure of the dual-rotor movement has been studied. The level of the similarity of the characteristic curve of the annular polishing pad and the Gaussian distribution has been evaluated by the tending factor. The pulse iteration method and the matrix calculation have been used to compute the residual error and the dwell time. The simulation result proved that the residual error (RMS) polished by the annular polishing pad had dropped 8.7% than that polished by the normal polishing pad with the same initial error condition, the surface quality has been improved by the new method.