Applied Mechanics and Materials Vols. 157-158

Abstract: The principle of reasonable modeling method using NX software was studied. The two modeling modes including history mode and history-free mode of NX were introduced. It was important that 3D model was created in reasonable method, so it was easy to modify the model and reduce the possibility of error when it was updated. The method ensuring relativity and parameterization of model by choosing correct modeling strategy was expatiated. In the end, the process of reasonable model creation is analyzed through a practice case.

Abstract: There are not a effective method to describe the distribution rule of shielding effectiveness for electromagnetic shielding clothing at present. A new analysis method of shielding effectiveness (SE) based on NURBS curve is proposed in this paper. With this method, the SE of the local clothing can be fitted with curve to observe the distribution rule. First, a design method of testing points on local clothing is given. Secondly, some concrete functions and program steps of curve fitting are listed. Finially, distribution image of shielding effectiveness on arm position is drew by some experiments. The results show that this algorithm can draw the 3D SE distribution image of local clothing is more correct and can show the distribution rule of electromagnetic wave in local human body.

Abstract: Hydraulic technology is applied to the hydraulic clamp. The combination of mechanical and hydraulic can make hydraulic clamp smart and compact, meanwhile, it achieves a great deal of additional power. The effect of hydraulic force increasing is entirely feasible. The principle, the mechanical structure and structure modeling of the multi-function hydraulic clamp are described in this paper. By optimizing the product design, the structure is more reasonable and compact ,the pressure of hydraulic clamp is adjustable.

Abstract: Abstract: Based on the Multi-body dynamics, the dynamics equation of the flexible blade in wind turbine is established by discretizing the rotating blade using finite element method. The simulation analysis of the single blade and the vibration modes of a 5MW wind turbine rotor are carried out by MATLAB. The first six natural frequencies and modes of the single blade and the rotor are figured out, and whose results are analyzed. The simulation results indicates that the coupling effect of the rotor can lead to dynamic stiffening. In comparison to the results in FAST, these simulation results show an outstanding agreement with the results calculated by FAST and hence approve the simulation method is valid and meanwhile give reference for large wind turbine design and running.

Abstract: The thin-walled ring rolling, a new rolling process, can produce the thin-walled rings that the traditional methods are difficult to process. It has the advantages of simple equipment, low investment and high productive. According to the mechanics analysis of the multiple rollers rolling, it established a mechanical model of small deflection bending compression rod. After solved the mechanics equations, it obtained the thin-walled ring’s rolling stiffness condition. From the theoretical formula, it could find that the increase of friction coefficient, ring radius, roller radius and feed per rotation were disadvantage for the thin-walled ring rolling stiffness condition. However, the increase of the ring cross sectional inertia was advantage for the stiffness condition. The theoretical formula could provide theoretical basis and guidance for the quantity design of roller pairs in rolling machine, design of ring cross section shape and selection of ring raw material.

Abstract: Based on the characteristics of the large state-owned central enterprises, this paper refers to an index system which can be used for evaluating their social responsibility fulfillment degree. It includes several procedures, such as determining each index weight by using G1 method, constructing a fuzzy comprehensive evaluation model, and verifying the feasibility through applying to an example. This research has effect on the scientificity of assessing their social responsibility fulfillment, and helps government and society to supervise and control the enterprises.

Abstract: To study the thermal effects on pollutant dispersion in the street canyon, a thermodynamic model is developed in this paper to predict surface temperature in street canyon environment, which can offer boundary conditions for CFD model. This model considered the shielding effect of buildings on solar radiation, the multi-reflection of radiation between building surfaces and the road. Furthermore, sensible heat exchange between the canyon space and the overlaying atmosphere was also modeled based on the classical theory of dynamics of atmospheric boundary layer. The reliability of this model is validated through a field measurement. Based on the thermodynamic model, a coupled calculation method is presented to predict traffic-related pollutants dispersion in urban street canyons under low wind speed conditions.

Abstract: This paper constructs four types of bioprosthetic heart valve’s parametric model via computer aided design, a series of accurate parameters of the bioprosthetic heart valve, such as radius of the sutural ring, height of the supporting stent and inclination of the supporting stent are determined. The finite element method is used to analyze the mechanical properties of the bioprosthetic heart valve in which geometric non-linearity and material non-linearity are all taken into account. The finite element analysis results show that the shape of the bioprosthetic has a significant effect on the mechanical performance of the valve. The stress distribution of ellipsoidal valve leaflets is comparatively reasonable. It has lower peak von-Mises, smaller stress concentration area than the other three types of valve leaflets. This work is very helpful to manufacture valvular leaflets with reasonable shapes and to prolong the lifetime of the bioprosthetic heart valve.

Abstract: In order to carry out automatic transformation to the two-roll reversible hot-rolling mill of a aluminum plate production factory, firstly a series of mathematical models of aluminum plate hot-rolling parameters are established, then a new optimization algorithm which is suitable for aluminum plate rolling production combined with the various constraints in the rolling process is proposed, and rolling schedule optimization software system is developed. Finally, by measuring the process parameters in rolling production site and applying the optimized rolling schedule to the rolling production, many test data are obtained. The analysis of test results and evaluation of the practical production show that the mathematical models established have high accuracy compared with the old rolling schedule. The optimization schedule can not only ensure the production quality, but also has higher efficiency and less energy consumption.

Abstract: According to the test-bed requirements and structural characteristics of gearbox ,this system for high-speed gearbox is designed based on LabVIEW. Firstly, programming mode and structure of the application program is introduced, secondly, data acquisition, bus technology of instrument control is presented. At last, the key technology of the program design is also expounded.