Advanced Materials Research Vol. 510

Abstract: This paper focused on introducing a real-time detection system of tool condition based on image processing technology and determined final algorithm after analyzing several different operators of edge detection. Firstly, the system will complete an acquisition of tool image, and transfer it to the computer. Then the image will be processed by some digital processing algorithms. At last, we can get the tool wear according to the size change of a tool. The result of this study showed that the detection system and its image processing solution could give a desired result. The detection accuracy could reach macron level, and the degree of automation could be improved too. So the system can be used to better meet the needs of high precision and high-speed in modern production.

Abstract: Under the intense market environment, concurrent engineering is considered to be an effective method to improve product competitiveness by more and more enterprises. As a new product development mode, it directly accelerates the design process of new products. Based on introducing the basic concepts of concurrent engineering, this paper discussed its key technologies in detail, such as process reconfiguration, DFX, PDM, CAX and TQM.

Abstract: A complex part, which has curved surface overall, is trial-manufactured with CNC machine. The NC machining process and technology of this full-surface part are studied in this paper. First, the 3D model of the part is created in the modeling module of UG system. Then, process analysis and scheme are developed. As the part has an irregular shape and the entire surface is to be NC machined, there are many difficulties during processing. The optimized process plan is determined. In the manufacturing module of UG system, the NC machining parameters are set according to the processing requirements, the tool paths are generated, edited and checked, and the NC code is generated by post processing. Finally, the part is manufactured using a 3-axis CNC milling machine with the NC programs. It has desirable shape and high accuracy. The result shows that the NC process is reasonable and efficient. CAD/CAM integration technology is applied successfully in this example. The methodology and technology introduced in this paper can provide valuable reference for processing similar parts, and it is also useful for correlational study.

Abstract: Chemical composition and metallographic organization were analyzed for the failure characteristics and main reasons of the imported slurry pump impeller used by Chehe Dressing Plant China Tin Group. A series of larger long strip form carbides found on the metallographic organization, which improving cut apart trend on matrix seriously, was the main reason of the impeller failure. Proper amount of vanadium, titanium and rare earth complex modifier can refine carbides and improve their morphology. The best mortar proportion was identified in the laboratory analysis conditions through the wear experiments.

Abstract: Grinding of metals is a complex material removal operation. Research on cutting process of a single abrasive grain is the basis of further understanding of grinding mechanism. In this investigation, the simulation and analysis for the non-uniform thermo-mechanical coupling intense stress fields in cutting zones of a single abrasive with negative rake are conducted by means of the FEM techniques. The cutting forces, the cutting temperature distribution and the strain rate in cutting zone are numerically demonstrated. Grinding mechanics are analyzed from microscopic view according to the simulation results. Research results facilitate a better understanding on the mechanics of grinding.

Abstract: Many frequency-domain characteristics parameters can describe the dynamic behaviour of Analog to Digital Converters (ADCs). This paper researched how to use a sinewave stimulus and spectrum analysis to test those parameters. It analyzed the spectrum of coherent sampling and incoherent sampling of ADC response to a specified amplitude and frequency sinewave firstly. Incoherent sampling causes spectrum leakage. To reduce the errors in calculating parameters introduced by spectral leakage, this paper multiply the data record by a window function in the time domain prior to the DFT process. Simulate results demonstrate that window function can reduced the spectral leakage introduced by incoherent sampling and increase ADC parameters calculation accuracy.

Abstract: In this article, a FEM model of high-frequency induction bending with gravity is established and with which the heated temperature, stress, deformation, residual stress and bending angle after cooling, etc are studied on different thickness ship plate. The results show that the steel plate can be heated to 860 above the austenitic temperature. Heating temperature is gradually decreased as the thickness increase, while there is a fluctuation in the late. As the plate thickness increases, in mm, the bending angle of the plate gradually decreases, and gradually increases in 8mm14mm, and then decreases in the late. Under the given heating conditions, thin plate and the mm thick plate have the best result of deformation. The stress in heat area reaches to the yield stress of Q345, and promotes plastic deformation due to the role of heating temperature gradient and gravity. When the plate has cooled, the residual stress is mainly concentrated at the bottom of the coil.

Abstract: Based on the epidemic of multi-functional furnishing, this paper presents the design of an angle-variable linkage through introducing the movement and compositing of this mechanism, modeling as well as analyzing the motion, excising kinematics simulation to the key parts. The mechanism presented successfully deforms accurately and locks stably under various conditions, satisfying the functional requirements of multi-functional furnishing.

Abstract: In this paper, taking a 7000 TEU container ship as an example, research on optimization design of mold lines of bulbous bow for container ships is carried out. Firstly, geometric parameters of bulbous bow are selected to be as variables to construct 7 computing molds, then CFD methods are employed to calculate ship resistance and parameters of wave field generated by ship moving, as well as Michell integration is used to determine the coefficient of wave-making resistance. Minimization of resistance is taken as the aim function to obtain the optimum geometric parameters of mold lines at bow. The results of mold testing express that the mold lines of bulbous bow for container vessel optimized by above methods are credible and valuable for engineering practice.

Abstract: The proposal of this investigation is the optimization design of bulbous bow-lines for a container vessel. The results of wave-making coefficients and relative data of wave-making field both from computation based on Green function method and Michell integral method are provided for 7 different designs of bulbous bow lines respectively in this paper. According to the minimum energy from the sample of average wave-making energy for each design of bulbous bow-lines, which is to be objective function in this computation, the geometric parameters for optimization lines of bulbous bow can be determined. Adopting CFD method, it is respectively calculated that the average wave energy change with the ahead extendable length of bulbous bow, the height above the baseline of bulbous bow and the transverse area of the bulbous bow at fore pole. By above three change curves, the optimization shape of the bulbous bow is gained. The resistance components and the wave-field for wave-making for ship hull by using CFD method have been validated based on corresponding model test results. Therefore, the optimized bulbous bow-lines can be used in the ship design practice.