Advanced Materials Research Vols. 538-541

Abstract: In the process of imaging, transmission and recording, there would be some decline in the quality of medical image typically displayed as fuzzy image, distorition, noise, and so on. To remedy the defects of traditional genetic algorithm of image restoration, the image restoration method was presented based on coding design, species initialization, genetic operator and update mechanism. The simulation experiment on image distortion caused by motion was also carried out in MATLAB 7.0 environment.

Abstract: In a transient analysis of an edge dislocation accelerating through the shear wave speed barrier, stress on the forming Mach fronts is analyzed, the wave front equations are given, as well as the effect of the acceleration of the moving edge dislocation on the geometry of the fronts.

Abstract: In manufacturing field, the geometric parameters measurement of tool is an essential process in manufacturing ball-end cutter. An optical visual inspection system of ball-end cutter parameters was studied through designing CCD camera, optical microscope, image grabbing card, visual light and 3D detection tables. Through the grabbing and processing image information of ball-end cutter, visual inspection method was applied to measure parameters of ball-end cutter. Some algorithms including the gray scale processing, median filtering, edge detection and least square fitting method of measured data were analyzed to develop image processing and tool detection software of ball-end cutter. The reliability and accuracy of this detection system were verified through the practical test.

Abstract: According to the location and number of temperature measuring points of the motorized spindle thermal error, a new method for optimizing the locations of thermal key points is proposed. Firstly, temperature measuring points are divided into groups by using fuzzy clustering method. Secondly, grey correlation model is adopted to analyze emphasis of each measuring point to thermal deformation in temperature field distribution of motorized spindle. Finally, temperature measuring points have been optimally selected based on modified coefficient of determination. Comparing to the conclusion of the existed literature, the results show that this method is feasibility and validity. The method can reduce the temperature variables and modeling time, and supply the theoretic support for the engineering experience.

Abstract: At present, there is no effective online debonding monitoring method for solid rocket motor. In order to solve the problem, the electro-mechanical impedance (EMI) method is introduced into online debonding monitoring for solid rocket motor (SRM). The EMI model of PZT and SRM is developed. The finite element method is employed to analyze the electro-mechanical impedance of the PZT, the conductance curves of PZT are obtained with different damaging phase of SRM, the root-mean-square deviation (RMSD) is used to assess the aging level. The result indicates that EMI as a new detection method is effective in identifying the existence and severity of cracks in SRM. As the debonding area increases, the difference of conductance curves becomes more obvious and the RMSD becomes larger.

Abstract: Traditional touch measure method has the shortages of easily distorting cigarette filter rod, long measure time, not high measure precision and not online implementing. In order to overcome these, imaging measure technology is used to measure it. Firstly, preprocessing filtering is operated on the acquired image. Then sobel operator is used to detect the edge and binary filter rod target image is obtained through morphological processing after falsehood edge eliminating. After that correlation parameters are gained. Parameters measuring absolute error for two images acquired from the same filter rod under different illumination is 1.848%. Experiment proves that the proposed method can rapidly and correctly measure cigarette filter rod. It can effectively measure filter rod in practice.

Abstract: In this paper, the dynamic mechanism is taken as an example for research sample size definition in Reliability Compliance Test and the Durability (Life) Test. When the fatigue life distribution is unknow, the test can be considered as a kind of success-failure test, which sample size is followed by binomial distribution. According to the central limit theorem, when the sample size is very large, it is followed by the Normal Distribution. When the two reliability targets and confidence degree were given, the total times of the test and the maximum times of the failure test can be calculated. In life test, the key point is to transform the test time into times of test.

Abstract: A microhole array is a critical feature in high-precision products, and acts as a microchannel for fluid delivery or a guiding hole for needle positioning. The precision of microhole fabrication affects the functions of product directly. This study presents a computer vision system that uses image processing methods to evaluate the positional error of a microhole array. A ceramic microhole array drilled by microdrilling process was made to demonstrate the proposed method. Analytical results show that the positional error is related to the precision of machining device noticeably and decreases with the number of holes drilled when adopts the mechanical microdrilling process.

Abstract: 2Cr13stainless strip is a very important raw material for producing Textile Accessories, owning to high economical efficiency of it with low alloying element mass fraction and highly C content. But the decay resistance of 2Cr13 is inferior relatively. We will discuss the decay resistance from alloying element and processes of quenching and tempering under different tensile force.

Abstract: Deformation of the big-diameter length rate shaft and turning process control mechanism were studied. When it was supported by the central frame, its theoretical mechanics models were established. Based on probability theory, considering the randomness of cutting force, elastic modulus, its length and its diameter, its theoretical model was established to calculate its standard deviation of the roundness. Moreover, its dynamic response finite element model was established, and the model was verified through comparison with the theoretical calculation results. The study provides the method and theoretical basis for the precision turning process planning of the big-diameter length rate shaft.