Advanced Materials Research Vols. 468-471

Abstract: The finite element models of biaxial shear capacity of RC frame columns are investigated.The calculation results and experimental results are compared using the different models.It is shown that different finite element models are effectively used to simulate the RC frame column. However, the simplified model may save computer time and be more convenient for the numerical simulation. Finally, the bilateral shear correlation of RC frame column is investigated using the simplified model. The results indicate that the bilateral shear correlation of the RC frame columns with different quantity of stirrups in two directions accords with the ellipse law and the fitting formula is presented.

Abstract: If the acceleration and deceleration of the flying shear track motion is constant, the acceleration and jerk of the tracking algorithm are not continuous, these result in a mutation of the force on moving parts and a great impact on the abrasion and service life of the equipment. Moreover, these affect the following effect of the servo system, make the cutting precision decreased. To improve the shear precision and cross section quality, an algorithm of the synchronous motion tracking of the flying shear is proposed. This algorithm directly uses the quintic spline curve profile to track the strip feed without any cam profile table. The quintic spline curve trajectory of the flying shear can make the velocity and acceleration of the blade rotation movement smooth. According to the length that user inputs, the control system uses iteration method to calculate the initial waiting length of the feed to carry out long cutting or short cutting automatically. Nonlinear synchronous movement is carried out to synchronize the horizontal speed of the flying shear with the feed speed of the strip on the cutting zone, which ensures the high-precision cutting length and smooth cutting cross section.

Abstract: In this paper, the detail numerical simulations were performed on the flow field of the scramjet combustor chamber with the hydrogen fuel, when the cavity parameters changed. The research results indicate that the effect of gas and air mixing and flame stability are altered when the parameter of cavity changed. From the research we will better understand the supersonic combustion. The high efficiency flame stabilities can be designed in future.

Abstract: Workover training is one of the necessary ways to ensure the safety of underground work, While the simulator training is an important tool for workover. For the high cost of training for operations, risk, and poor repeatability characteristics, we use the simulator training to simulate workover issue and achieve the purpose of operating the training. The article describes a workover simulator function, structure and working principle, explains the workover simulator master console’s components, front console and graphic control system to achieve the main technologies and key issues in the Windows system. Finally, the article gets that simulator training detected overflow, wellhead pressure control after shut-in. The simulator hardware equipment is compact, portable, can be taken to service at the first production site.

Abstract: The structural feature of EDM copper electrode is analyzed in this paper from the aspect of machining process, and the NC machining process is studied. The CNC machining method of EDM copper electrode is described briefly; the problem that frequently occurs in the machining that the copper electrode is deformed is solved, and the machining criterion of EDM copper electrode is discussed as well.

Abstract: Rear axle spiral bevel gear of motorcar, as its special shape structure , alveolar much deeper than straight bevel gear , and has spiral angle effect , therefore, extrusion of rear axle gear than extrusion of straight bevel gear is much more difficult , deal with the problems, have made closed extrusion new technology of rear axle gear , designed new type die structure, die adopt fluctuateing concave model level bisection ， pre-stressed composite concave model structure , concave model and model core floating , parts have no fly side , tooth surface can reach the level of rough milling ,higher production efficiency and life of die , satisfied production requirements. Process test showed that compared with the open die , required extrusion distortion force reduced 50% , increase material utilization 15%, debase electric power consumption 50%, with significant economic benefits .

Abstract: China's agricultural production in the course of a wide range of point source pollution, large and difficult to control. Symbiotic system rice-frog as a good traditional agricultural production, with outstanding ecological, economic and other values, has been identified as globally important agricultural heritage and the first to be protected. Summary of agricultural non-point source pollution in the status quo to explain the symbiotic system rice-frog to reduce agricultural nonpoint source pollution in the role, made on the basis of frog in rice paddy planting to optimize the structure, development of ecological agriculture is the agricultural non-point source pollution prevention and control an effective way.

Abstract: Based on the investment risk characteristics of large-scale hydropower project, the risk identification of investment for hydropower project is investigated according to the project Work Breakdown Structure(WBS) and Risk Breakdown Structure(RBS). The method for estimating the investment risk of hydropower project is applying Monte Carlo simulation technique. This method is applied to analyze the risk of the Hsin-an River hydropower project in the Zhejiang Province based on experts' experiences. Good result is attained.

Abstract: For the present situation of decision-making errors and poor regulation caused by lack of operational monitoring in current development of China’s regional logistics system, the operation monitoring system of regional logistics system was designed in the paper. It consisted of index system, evaluation method, diagnosis and early-warning. By analyzing the content of operation for regional logistics system, the boundary of monitoring was defined and an index system was constructed; the grey relational grading evaluation model was introduced in monitoring and evaluation; diagnosis and early-warning could be realized by means of improved radar chart. It is expected to provide theory and methodological tool for operation monitoring of regional logistics.

Abstract: To improve the stability and precision of noncircular manufacture process, the variable spindle speed turning is applied to noncircular turning process. The variable spindle turning system is designed. The character of variable spindle speed is analyzed. The linear servo unit available for variable speed noncircular turning process is designed. An active disturbance rejection control technique is applied to servo unit. The experiment results show that surface quality and tracking error of variable spindle speed noncircular turning are better than constant speed machining. The linear servo unit is able to track the desired trajectory of cutting tool motion.