Applied Mechanics and Materials Vols. 52-54

Abstract: After 4 times thinning spinning, the C-276 tube with 2mm thickness and 561.5mm diameter was thinned to 0.42mm, the length was extended from 300mm to 1200mm. Discuss the problem of drum instability during the process of spinning, as well as the effect of fit clearance between mandrel and workpiece on the spinning stability. Applied the large-scale finite element software MSC.MARC to carry on the simulation analysis of the drum instability phenomena of loading workpiece under the condition of different fit clearance, put forwards measures to control the instability, so as to provide theory instruction for producing barrel with extra thin-wall and height diameter/thickness ratio which can fit the precision requirement.

Abstract: This document focuses on the case that optimization direction is hard to determine in aerodynamic optimization processes, and proposes an intelligent approach based on ANN learning, followed by result visualization using data mining technology. It can not only help visualize the optimization process (qualitative analysis), but also determine the optimization direction (quantitative calculation), which can save time of frequent CFD calculation and obviously improve efficiency in aerodynamic optimization.

Abstract: To calculate the pressure distribution of oil film on spherical port plate of Innas hydraulic transformer (IHT), finite difference method (FDM) based on boundary fitted coordinate (BFC) technique is presented. Spherical curvilinear grid system was obtained with a coincident boundary of irregular physical area. The flux conservation form of Reynolds’ equation was applied as control equation. By FDM, the thickness distribution and pressure distribution of distribution pair were calculated. It shows that BFC transformation method is advantaged to closely simulate the physical domain with complex geometrical boundaries.

Abstract: Environment measurement technology of aircraft platform is the foundation of environment prediction, while inductive technology of environment measurement data is the support of environment prediction. To analysis how the vibration of different channel and in different position affect the equipment on board, it’s awfully needed to classify the vibration data of aircraft platform according to how was the aircraft flying and where was the sensor placed. However, the traditional method for categorizing gives the sort first, and then make certain if one sample belongs to this category, which is easy to withstand the influence of man-made factors. As it hard to fix the categories first for the vibration on aircraft platform, we put forward using clustering analysis into the categorizing of vibration measured data to eliminate the influence of man-made factors. This method is the improvement of the current inductive method for vibration environment measured data.

Abstract: Fuel cell vehicle powertrain is a complex electromechanical system related to electrochemistry, power electronics, power transmission and control systems, network and communications and other disciplines. Therefore, this article has clearly made the concept of fault and fault diagnosis, and conducted the preliminary study of the method of fault diagnosis for the fuel cell vehicle battery, and will adopt the model-based fault diagnosis method to achieve battery fault diagnosis.

Abstract: This paper discussed on an application of the statistical based analysis approach on fatigue failure of carbon steel. A new statistical based method known as Integrated Kurtosis-based Algorithm for Z-filter (I-kaz) and the quadratic mean were used in this fatigue failure assessment. Fatigue tests were performed according to the ASTM E466-96 standard with the attachment of a strain gauge to the tested specimen. Test was performed at a constant loading leading to the collection of strain data throughout the test. A fatigue based data acquisition system was used in this work. All obtained data were analysed using specific software. Fatigue failure behaviour was observed through the strain signal analysis to investigate significant correlation between I-kaz coefficient, root mean square value and the fatigue failure behaviour. It was found that I-kaz coefficient and root mean square value are proportional to life cycle.

Abstract: In the seismic design of pile foundation, current research mainly adopts the theory of auxiliary experiences engineering design methods. In particular ground, the pile must be specially designed to meet the seismic requirements. In this paper, with large scale finite element software ADINA,a 2-d finite element entity model is established to calculate and analyze the influence of soft soil to the dynamic interaction of soft pile-soil under the earthquake. The maximum displacements and acceleration of the measuring points on the pile are analyzed in different thickness and position of the soft soil. Calculation results show that: Soft soil effect the maximal displacement and acceleration of the measuring points on the pile which changed with the different thickness and positions of the soft soil. It should be noticed in the design of pile foundation and ground treatment.

Abstract: The flow measurement of the natural gas directly influences the economic benefit, which includes development, operation, allotment and the utilization in the industry of the natural gas. Moreover the structure of the pipeline is the main factor for the accuracy of the flow metering. In this paper, the research on the internal flow field of various kinds of pipe structure with the remit pipe, which are the different inflows and whether equipped with the panel rectifier separately, is done with the method of the numerical simulation and the experiment. The conclusion shows that the desire length to recover the full development turbulence section in the downstream of the remit pipe is most in the pipe structure with the stagger inlet-outlet and no rectifier. While that in the pipe structure with the opposite inlet-outlet and with a rectifier reaches the least. It can be got that the most appropriate installation site of the flow meter and the design of the pipe structure of the natural gas from the research on the influence pattern of the gas flow field.

Abstract: In this paper, the cooling process of Large-diameter bars is simulated by the 3D numerical simulation calculation method of Finite Element Coupling Field. Then, the influence, which about the controlled cooling inlet pattern on the cooling effect, has been analyzed. The results show that the bar cooling effect of annular nozzle inlet cooling pipe is the best among the several inlet patterns in this paper; relatively the bar cooling effect of four circular nozzles inlet cooling pipe is the worst among the several nozzles patterns in this paper. This numerical simulation result provides reference for choosing inlet pattern of bar controlled cooling equipment.

Abstract: The determinants and roles of bank lending, which is formal financing channel and outsides the supply chain, and trade credit, which is informal financing channel and insides the supply chain, are analyzed here through listed firms in China over 2006-2009. In our model we consider the trade credit as a complementary role and more important for small firms. Also with the firms different industry classified, we give the performance of bank lending and trade credit respectively. The estimation results and analysis are given detailed in our paper.