Advanced Materials Research Vol. 818

Abstract: In order to deal with the difficulty of magnetic field adjustment in permanent magnet synchronous machines, this paper proposed a novel paratactic structure hybrid excitation synchronous generator (HESG) and presented the basic configuration and its principle. Then, with the analysis of armature reactions, it introduced the detailed working performances of permanent magnet synchronous generator (PMSG) and the electric excitation synchronous generator (EESG) in HESGunder different field current conditions. We can classify the operating modes of HESGinto three categories: double-generation mode, single-generation mode and generation-motor mode whose boundaries were deduced. Finally, the experimental results proved the correctness of those analyses.

Abstract: Along with advance of equipment manufacture engineering item complexity, retrench of development time, increasing of product quantity, and bring huge challenge to configuration management of traditional paper-based technique. This paper taken engineering project as an example which participated and implementary in, expounded the application of PDM system in four aspects of configuration management: design configuration, control configuration, on-the-spot report configuration, and audit configuration. It was clarified important significance which is PDM system advanced level and efficiency in the configuration management of equipment product development.

Abstract: Stress strain analysis of elastic halfspace by means of Gauss numerical integration and Jacobean of transformation is presented. The arbitrary shape and general course of the loaded area in nodal points is allowed by use of 4-and 8-node isoparametric elements, numerical integration and Jacobean transformation. Results of numerical examples are compared with other solutions.

Abstract: Main aim of our recent research activity is the theoretical and experimental investigation of hard turning of AISI H13 (52 HRC) hot work tool steel. Chip removal processes are of essential importance in modern manufacturing technology. The demand for higher accuracy, better surface roughness, more economical production, and miniaturization are constantly growing. This determines continuous research and development of cutting processes under special circumstances. Numerical simulation plays an important role in evaluating of the cutting processes, and in prediction of forces, chip formation, distribution of strain, strain rate, stresses, and temperature. Cutting experiments with varying feed rate and cutting speed were carried out to determine their effect on surface components of resultant force. 3D finite element model was proposed to simulate the chip removal process during turning of workpiece material AISI H13 (52 HRC). This paper gives a summary about the comparison of theoretical and experimental results. It was found that boundary conditions, such as finite element size, mesh density, material separation method has significant influence on chip morphology and value of cutting force, too.

Abstract: ndustry is the foundation of national economy and military development, and machinery manufacture and production is the main content of industry. Therefore, each country attaches great importance to its own machinery manufacture capacity and production levels. Influenced by the special historical factors, China's economy started relatively late, with a low machinery manufacture capacity. To essentially change this phenomenon, the selection and processing technology of metal materials must be optimized. This paper analyzes the concept and characteristics of metal mechanics, together with the present situation of China's machinery manufacture and production. After studying the relationship between metal mechanical and machinery manufacture and production, it is found that the use of metal mechanics can improve the quality of mechanical products.

Abstract: This article presents the method of determination of friction parameters for soil structure interaction with and without slide joints in the subsoil of structures. The results for constant and nonlinear distribution of C_1x, C_1y parameters are compared and derived friction parameters have been used for the FEM calculation of the stress condition of the real foundation structures.

Abstract: This article researches AMR environment modeling, path programming, as well as its motion controlling in accordance with AMR structural model of experimental reference system under dynamic uncertainty surround, based on summarizing advanced theories about intelligent navigation on board and aboard. It establishes theory foundation for going a step further researching path programming and motion controlling of AMR.

Abstract: Based on the dynamic mathematical model of three-phase grid-connected inverter, two kinds of control strategies are compared, one is double closed loop control based on grid voltage orientation theory, the other is direct power control. According to the mathematical model of two-phase rotating coordinates of the inverter, in double closed loop control theory, the purpose of control of the inverter by decoupling control and PI control is achieved. From the point of energy on direct power control system, the active, inactive power of output AC of inverter are calculated ,and suitable space voltage vector was selected after comparing with the given values to realize the direct control of the power set point. The basic theory of two control strategies and implementation method are included, and the simulation model was established based on MATLAB/Simulink. And their simulation results, characteristics of two kinds of control methods were compared through simulation data analysis. On the basic of results, the direct power control is better than the double closed loop control.

Abstract: The vibration signal of gear box shows the information of its running state. The thesis explains the basic model and its algorithm of blind source separation, simulates the common fault of gear box in the condition of laboratory, disposing the fault signals of gear box by blind source separation and intelligently identifying the faulty condition of gear box by the method of support vector machine (SVM) after extracting eigenvector, which achieves success.

Abstract: A key management strategy is presented for heterogeneous wireless sensor networks. The wireless sensor networks have some sensor nodes which have greater power and transmission capability than other nodes have. Both ordinary nodes and heterogeneous nodes are evenly distributed in sensing square area respectively. The pairwise keys between nodes are established through utilizing the concept of the overlap key sharing and the random key predistribution scheme. Analysis and comparison demonstrate that the connectivity and security of wireless sensor networks have been improved obviously even with some heterogeneous nodes.