Advanced Materials Research Vols. 472-475

Abstract: It is necessary that the internal and external contours are extracted from the image of hot long shaft forgings, while the forgings are measured by CCD measurement method. In the light of the blurry internal edges in the image of the hot forging, a method based on quadratic B-spline curve is employed to extract feature points. In order to remove the pseudo features, a method based on maximum correlation is presented. In accordance with continuity of the internal contours, quadratic B-spline curve is used to fit the internal contours. Experiments show that this algorithm can effectively extract accurate internal contours for images of hot squaring and chamfering forgings. The extracted contours could provide basic data for subsequent 3D reconstruction and geometric measurements.

Abstract: In this paper, we address unrelated parallel machines scheduling problem with fuzzy processing times considering the minimization of the total tardiness cost. The tardiness credibility index of jobs is given to estimate the possibility of job’s tardiness, and a mixed integer programming model (MIP) is formulated for total tardiness cost based on fuzzy theory. Solving the MIP problem is NP-hard, thus a tabu search is designed to solve such a difficult problem. The results of computational test show the feasibility and effectiveness of the developed model and algorithm.

Abstract: One-dimensional (1D) nanowire is one of the most important components for nanosized electronic devices’ development, sensors. Eu3+-doped lanthanum phosphate nanowire has been synthesized via hydrothermal method. The sample is characterized using XRD and SEM; SEM images show the diameter of LaPO4:Eu3+ nanowires before heat treatment is about 10 nm. After sinter, the LaPO4:Eu3+ nanowire becomes particles. The particles grow up and the luminescence intensity becomes lower with the sintering temperature going higher, while the life time of 5D0→7F1 transition is longer. It is suppose that the perfect lattice is not benefit to the dopant ions into.

Abstract: A two-dimensional numerical gas-solid flow models without chemical reactions is developed to simulate gas-solid flow in the fluidized bed boiler through MFIX software. Platen heating surfaces is considered in the upper of the furnace. Considering that velocity and concentration are the most factor effecting on erosion, there are three main area suffered serious erosion: (1) There is a maximum velocity at the position ( X = 57 cm, Y= 60 cm) on the right side of the wall, which will produce serious impact and erosion. (2) In the vicinity of position (X = 57 cm, Y= 140 cm) will suffer serious impact and tear. (3) As to the platen heating surfaces, the lower part which connect with flow is slightly wear and impacted. While the velocity on the right part is relatively large, especially in the corner of position (X = 24 cm, Y= 147 cm) reach a maximum.

Abstract: Paper has been removed at authors request due to significant errors.

Abstract: Abstract: The die casting technology has more wide application in the production of a variety of small appliances and cooking utensils. However, it is difficult to set casting technology parameters, and the life of casting die is short. In this study, the numerical simulation software was employed to simulate the aluminum mold. By analyzing temperature field, the temperature changes of the mould surface were predicted in the die-casting cycle. According to the thermal stress simulation and mathematic model, the thermal stress and strain variations were presented in the process of casting, The thermal stress changes of A, B point on the mold surface were compared under the different pouring temperature, die preheat temperature and cooling water temperature. On the basis of the simulation results, the best die casting technology parameters were selected. The life of die casting dies is predicted by mathematical model, and the simulation results agree well with the result of experiment. This study reached the conclusion is that the die life prediction method is reliable.

Abstract: The high-speed electric spindle is the key part of the machining center which performing high speed precision machining. In order to ensure the electric spindle running under the smooth and steady state, it is necessary to prevent and discover the abnormities during the running process of the electric spindle by the experimental test and analysis. In this paper, the vibration order analysis method combined with the experimental modal test is utilized to measure and diagnose the abnormities of a high speed electric spindle.

Abstract: The magnetic flux leakage (MFL) technique is widely used as a Non-Destructive Testing (NDT) method for welds [1]. Because of the specialty of fillet weld structure, the defect may not be in the location suitably detected, which is normally at the center of yoke poles, and the rate of detect-ability would decline. In this paper, we focus on the yoke-magnetization testing for a fillet weld, and it is studied the influences of air gap between magnetic poles and specimen surface on MFL density at an artificial flaw by Finite Element Method (FEM), and also the influences of distance between magnetic poles and fillet weld on MFL density. The results show that the MFL density observably decreases as the air gap and the distance increase.

Abstract: A high-speed data acquisition card using USB 3.0 interface has been designed in order to solve the problem that traditional data acquisition card could not take both data transmission bandwidth and easy connection with PC into account. The data acquisition card controlled the dual-channel 12-bit 20Msps ADC for asynchronous parallel sampling using FPGA as core control module, which made the sampling rate up to 40Msps. The sampled data which was processed by FPGA transferred synchronous from FIFO interface to PC via USB controller. The basic structure of hardware and the basic design method for software and firmware were given in this paper, in which how to use FPGA to realize FIFO was elaborated in detail. The timing simulation of using asynchronous parallel A/D conversion technology and using ADC device of 40Msps sampling rate for FIFO internal data transmission were simulated respectively, thus verified the reliability of asynchronous parallel A/D conversion.

Abstract: Firstly, this paper put forward knowledge acquisition and knowledge organization from the yard plans through KSP. Furthermore, the paper explores the approach of the construction of Production knowledge representation system. Finally, the effectiveness and reliability of the knowledge-based berth and quay crane assignment has been verified by the case studies conducted.