Advanced Materials Research Vols. 328-330

Abstract: This paper analyzes the influence of processing surface curvature of the free surface to the cutting width to improve the cutting width of free surface. The results show that this analysis is feasible to improve the process if the machining accuracy allows. It shows that the curvature of the machined surface and the curvature of the cutting tools have a great impact on the cutting width if they are matched reasonable. Therefore, analyzing the curvature of the surface of the surface of free-form surface machining can improve the cutting width effectively.

Abstract: Through the analysis and research on three fractal models of normal contact stiffness of joint interfaces, the differences between them can be found. Furthermore, numerical simulation was carried out to obtain the complicated nonlinear relations between normal contact stiffness and the normal load. The results show that the normal contact stiffness increases with the normal load, decreases with G but complicatedly varies with D. According to different fractal dimension, we can chose an appropriate one among the three fractal models of normal contact stiffness of joint interfaces when describing normal contact stiffness of joint interfaces.

Abstract: A spiral micro-groove structure in plane was processed by P-E method in this paper. The shapes of groove structure was restricted by P-E depth a_ph and feed f. The influence a_ph and f on the height of fin and matching relation between a_ph and f were analyzed, and optimal value of a_ph and d_ph was obtained. The highest fin was achieved when d_ph was the optimal value in processing. Meanwhile, the effect of rotational speed n on the morphology of micro groove was studied.

Abstract: Shanghai Center Tower is the tallest skyscraper under construction in China with the height of 642 meters. In order to reflect the real structural status of Shanghai Center Tower during the construction period and running period in three dimensional graphics, a Structural Health Monitoring Software System (SHMSS) is developed. The CAE software system consists of three function modules such as Modeling module, Data Management module, Post-Processing module. The Modeling module could build a 3D model confirming to the real Shanghai Center Tower based on the Building Information Modeling (BIM) concept; the Data Management module could access the engineering data produced by the sensors; then in the Post -Processing module, various data about the Shanghai Center Tower could be processed and structural parameters such as member force, displacement, wind pressure would be displayed in the 3D model.

Abstract: A novel structure of vane pump is brought forward, a new assembly relation among vane, sleeve, port plate and stator is created, mechanical bearing condition of new-type vane is preferable than traditional vane, vane is kept clearance with stator all the time as long as dimensions of those parts are reasonable. Modal analysis and optimized design for vane is made with finite element analysis software ANSYS. By simulating analysis for pump, simulation result shows that this novel vane pump is feasible. Compared with traditional pump, wear and vibration of novel vane pump can be reduced, volumetric efficiency of pump can be enhanced remarkably, the novel vane pump has certain application value.

Abstract: Though spatial cam has been widely used in various fields of machinery and equipment ,but it is seldom used in continuously variable transmission situation. So firstly the working principle of spatial cam for CVT is introduced, and then equations of the pitch curve and cam contour are derived .In order to get the required dimensions and parameters of spatial cam during three dimensional modeling, program is developed with programming software Mathcad and the corresponding programming flow chart is listed out. And the running results of the Mathcad program and features of spatial cam in Pro/E are correlated to realize solid modeling, at last an example is given to demonstrate the feasibility and flexiblity of this method.

Abstract: The heat-resistant steel after aluminized was treated by laser shock processing (LSP) with high power Nd:YAG laser, and then was tensile tested at 400°C. The effects of the high-temperature behavior after LSP were analyzed from residual stress and fracture organization. The results showed that the yield strength and tensile strength of heat-resistant steel after aluminized were improved obviously during the tensile testing at high temperature, and the High-temperature fatigue life of 00Cr12 with composite processing was enhanced vastly. Compared with the LSP, the High-temperature fatigue life of 00Cr12 heat-resistant steel by aluminizing and LSP had a larger increase.

Abstract: Most resources used in a project will have an easily determined cost. We need to know which staff members can work on which parts of a project and what needs to be done, and when. Project time management should be broken down, step by step, just as other parts of the project are broken down in the planning phase. This will help make sure that everything is done when it needs to be, and to keep the project from going over its budget because it went well past the time scheduled for it. A project manager often need to control the whole time of the project and grasp the key process in those tasks which can shorten the period and reduce the cost. This paper discusses the algorithm of AOE-net in the critical path and its application to evaluate the completion time in the network planning of project time management.

Abstract: In order to overcvome the shortage of current dust control technology in coal mine, especially the traditional water spray method, a two-phase foam materials preparation experimental system was established based on the simulation of water and air conditions in underground coal mine. And a new technique which can prepare high-performance foam was proposed, and the main technical parameters and application conditions to implement foam dedusting were determined through plenty of experimental. Then, the new technique had been applied in two large underground coal mine. The results show that its dedusting efficiency to total dust and respirable dust reached 90.5% and 85.4% in the fully-mechanized excavated face, as 1.97 times and 1.88 times higher than water spray respectively. However, its water consumption is only as 10% to 20% as conventional water spray. It is proved that this new technique for preparation of foam can reduce mine dust concentration remarkably and improved the working environment obviously, and has a broad application prospect and promotion value to control dust in underground coal mines and other related industry.

Abstract: Fatigue tensile treatment was performed on 00Cr12 heat-resistant steel specimens which had been treated by laser shock processing (LSP). The unilateral tolerance factor statistical analysis method and the two-dimensional Weibull distribution method were used to predict the values of fatigue safe lives of the specimens respectively. The results indicate that the fatigue lives of 00Cr12 specimens were enhanced greatly after LSP, and improved by 62% compared with the specimens which were not treated by LSP. The unilateral tolerance factor method obtained an exact estimation value of the fatigue safe life; while the two-dimensional Weibull distribution method can get a range of values of fatigue safe lives, the fatigue safe lives of the specimens which after LSP were a range from 116570 to 150230, the average value was 132330. The two-dimensional Weibull distribution method has more engineering applicability and can be used to estimate the fatigue safe lives with fewer experiments.