Advanced Materials Research Vols. 230-232

Abstract: Vapor seal is an indispensable component in steam turbine for economic and safe operation. The flow characteristics in vapor seal have a significant effect on the performance of vapor seal. Considering the flow field characteristics and engineering applications, the following work has been done: First, the models of the labyrinth glands with stepped teeth have been established through Computational Fluid Dynamics software Fluent. The full-flow simulation result is acquired. Second, based on the numerical results, the characteristics of the flow field in stepped labyrinth seal have been studied. At last, the best structure for stepped labyrinth seal is achieved.

Abstract: Electromechanical impedance technique which based on smart material is a new method for structural damage detection, and it could be widely applied in structural health monitoring field. However, a very expensive and bulky analyzer is being used to measure the impedance, which is not practical for on-line system. Therefore, this paper developed a device that can measure the electric impedance using small modular electric components and reasonable circuit. Experiments are carried out to test the aluminum beam crack. Results indicate that the device can measure the electric impedance and detect the damage effectively. The proposed method provides a solution to miniaturize the impedance-measuring equipment and reduce the cost of measurement.

Abstract: Based on comprehensive quality management theory, we have studied quality factors of fly ash high-performance concrete in construction, put forward the method of beforehand control, course control and afterwards control. From the project construction of the actual conditions, the raw material selection, mixture design and try gradation and concrete performance of fly ash concrete, has been comprehensively studied and analysised. The optimal dosage of fly ash has been determined with good workability of different fly ash concrete strength grade and mechanical properties meeting the design requirements and good durability, which demonstrates the good effect of the high-performance concrete implementation of total quality control management through the engineering practice.

Abstract: First, tensile creep curve and creep propagation tests are conducted for austenitic stainless steel 0Cr18Ni9, i.e. 304 stainless steel at 550°C. The corresponding time hardening creep law is given for stresses ranging from 240 to 320 Mpa and the creep crack propagation length under a tension load of 10kN is measured by using QUESTAR long focus microscope system. Second, with the commercial finite element (FE) code ANSYS, the critical crack tip opening displacement (CTOD) is considered as crack propagation criterion to simulate the creep crack growth in the standard compact tension (CT) specimen. The FE predictions of the creep crack length in the primary and secondary stages are found to agree reasonably with the experimental results. The maximum computational error between the predictions and the experiment results is within 10%. Hence, the critical CTOD is a feasible criterion for crack growth simulations at elevated temperatures.

Abstract: Various participants in the supply chain must combine their own quality control and the relevant coordination decision-making with other enterprises to ensure they have strong competition position in the supply chain. Transactions among the manufacturers and retailers with the existence of asymmetric information in the electronic production system, as a result, the game will existent among them. In this paper, application of signal game theory to quality control of retailers are studied and the signaling game model of equilibrium to satisfy the three conditions are also be analysis.

Abstract: The success of wireless sensor networks (WSN) depends on two factors: 1) how well the service area is monitored by the WSN's capability to sense the intended phenomenon, and 2) the way that the WSN communicates the sensed phenomenon for further analysis by the service center with acceptable time duration. The simultaneous optimization for both the sensing and communication problems is a grand challenge, especially when the service area is harsh and it can't be accessed easily by human. In this paper, we have proposed a non-uniform constructive scheme to sense and communicate the service area through a cell-by-cell, where each cell is selected randomly and the cells may have different sizes. The experimental results demonstrate the feasibility of the non-uniform constructive scheme in selecting and placing sensors to sense and communicate over the service area with minimal uncovered area and minimal overlapped sensors.

Abstract: This paper , taken production process in typical production department of glass, cement, chemical industry for example, analyzes their dosing process and technical characteristics , and summarizes that the work of the basic ingredients link in various production departments is in common and other links is arranged according to production requirement combined with the different ways of transporting and feeding materials. The order of production is different, so the number of ingredients link and the complexity of working order are not the same. With "intelligent learning control model" applied to the system, it realized the online self-studying learn and self-adjusting in weighing control, which can on-line judge the speed and precision of weighting, automatically adjust feeder’s speed and advanced argument of stopping-feeding. In a word, in design of control strategy and control software, various characteristics of the ingredients system are taken into full consideration, which choose corresponding weighing method and the control strategy according to the difference of accuracy requirement.

Abstract: This paper discusses the structure of wireless sensor network (WSN) and the key technologies for the monitoring of machine tools. Multi-sensor is used to monitor the acoustic emission and vibration signal during the manufacturing process of machine tools. Vibration signals and acoustic characteristics are extracted by using wavelet analysis. Based on the fusion of BP artificial neural networks and multi-sensor information, the monitoring of machine tool is carried out in the environment of wireless sensor network.

Abstract: Aimed at the body of SUV vehicle , according to the criteria of FMVSS216 vehicle safety regulations , in LS-DYNA software environment , the simulation analysis of effects of the design parameters of main components of the body on roll crashworthiness in the process of vehicle crashing and rolling is presented in the paper , based on finite element analysis method, with the test methods of applying pendulum collision. The characteristics of the crashworthiness and energy absorption of the pillar pendulum which have different design parameters, such as shapes and thickness, et. al., are emphasized particularly in the paper. A simple finite element model of SUV is established, the effect of different design parameters of stiffness of body cover to the whole distribution of energy absorption and the reasonable transfer of total energy is discussed. The noticeable issue and advice on body design of SUV is proposed.

Abstract: E-bussiness has grown rapidly in the last decade and massive amount of data on customer purchases, browsing pattern and preferences has been generated. Classification of electronic data plays a pivotal role to mine the valuable information and thus has become one of the most important applications of E-bussiness. Support Vector Machines are popular and powerful machine learning techniques, and they offer state-of-the-art performance. Rough set theory is a formal mathematical tool to deal with incomplete or imprecise information and one of its important applications is feature selection. In this paper, rough set theory and support vector machines are combined to construct a classification model to classify the data of E-bussiness effectively.