Advanced Materials Research Vols. 230-232

Abstract: The method of polar-center transformation was applied to the measurement of roundness error; the mathematic modeling of axial round error was established base on the method, to solve the roundness error on engineering. The application software was written base on the mathematic modeling; therewithal the system of measure round error consists of the software and same auxiliary equipment components, and was applied in practice, the result show that the mathematic modeling is correct. So the foundation was established to develop further high accuracy system of measure round error.

Abstract: The relative merits of accuracy engraving technique and rapid prototyping technique during processing are discussed. Because the product dimensions are small and the strength of the rapid prototyping sample workpiece in vertical direction is too small to meet the engineering design requirements, the method using accuracy engraving machine to replace rapid prototyping machine to design product with large size and need to assemble like motorcycle cover is proposed. If the product size is too large, it can be split and every part is carved with the accuracy engraving machine, and then they are sticked together to finish the whole part. So the speed of new product development is accelerated, the cost of new product development is decreased, the rapid manufacturing is realized and the traditional design method using only RP machine is improved. This method has been applied to the development for a new motorcycle cover and the application method is expounded.

Abstract: According to its structure and dimension, the original stamping forming process of the lipstick casing pipe was analyzed. In view of such drawbacks as dispersed working procedures, lower efficiency and unstable product quality in the original manufacturing process, wall thickness of the lipstick casing pipe was modified and became thinner than its original size with the premise of ensuring utility performance. A new manufacturing process for the modified lipstick casing pipe was provided and a fully automatic stamping die, which is more secure in operation, lowers raw material expense and has higher production efficiency, was designed.

Abstract: The importance of cam contour curve and the necessity of cam reverse engineering are discussed. The error sources during the course of cam reverse design are analyzed. The growth form innovative design method is researched, especially product structure growth form design method. The information of structure, dimension and tolerance should be perfected gradually during the course of growth form innovative design, and finally perfected when the product structure is finished, furthermore, using the current structure, dimension and tolerance information to conduct evaluation and control in the grow direction during the design process, to achieve the ultimate purpose of optimization design. Taken the innovative design of an precision cam as an example, the reconstruction of product structure and the product prototype reverse design are finished, and then the product is innovative designed. A practical designs technical ways based on growth form innovative design is systemly provided.

Abstract: Spinel LiMn₂O₄ were prepared by a molten salt combustion method at 600°C. The phase composition of the products was investigated by X-ray diffraction (XRD), and the electrochemical performance was tested by a coin-type self battery. XRD results presented that the purity and the crystallinity of the products increased with extending calcining time. Single phase LiMn₂O₄ could be prepared at 600°C for 6 and 12h. The ratio of lithium/manganese also affected the phase compositions of the products. The purity and crystallinity of the product with the molar ratio of Li/Mn=1.1/2 were higher than these of the product with the molar ratio of Li/Mn=1.05/2. The performance tests indicated that the electrochemical performance of the product prepared at 600°C for 6h is the best. The initial discharge capacity was 112.8mAh/g, and after 20 cycles, the capacity retention is 81.8%. The product with Li/Mn=1.1/2 had better electrochemical performance than the product with Li/Mn=1.05/2.

Abstract: In face of the problem of difficulty in traditional aging fuzzy reliability solving, a deep research is conducted on the aging fuzzy reliability calculation method of components and systems based on discrete-time condition. On the basis of aging fuzzy reliability calculation, the concept of time axis division and fuzzy theory operating rules are introduced. The degree of reliability calculation method of aging fuzzy reliability of individual component and system under the condition of discrete-time is also deduced, and avoid the integral solving problems when the ageing fuzzy reliability of components and systems is calculated. Finally, the analysis of practical example is presented to show the method is feasible and precise when time interval is rationally divided.

Abstract: Spray field of the shower nozzle has the characteristics of speediness and instantaneity. The interaction among particles in droplet segment and atomization section makes the direction of movement complex and the profile of the image principal part area unclear. It is difficult to divide the images into principal part and background. Lots of threshold segmentation technologies used recently can’t receive satisfied result in the image process of shower nozzle spray field. Therefore, this article proposes a new extracting technology to extract the threshold automatically based on Otsu Method, which uses absolute value to calculate the average gray gap between section and overall and find the suitable threshold. The result of binarization segmentation by this threshold shows that it can express the characteristics of water jets completely and reduce information losing.

Abstract: In order to fully understand dynamic behavior of the thickness variation and conduct off-line process tuning, a dynamic simulator for the feedforward Automatic Gauge Control (AGC) for a hot strip finishing mill in China Steel Corporation is developed. One of the major factors influencing on deviation of delivery thickness of the steel strip is the temperature variation caused by cyclic contact between the steel strip and beams, which transfer the strip in the hot rolling process. This temperature difference brings about hardness variation along the strip, which is known as skid marks. Simulation results and system analysis verify that the feedforward AGC system is capable of overcoming the high frequency thickness variation disturbed by the cyclic temperature difference, which usually cannot be effectively compensated by regular gaugemeter AGC feedback loop. A strategy to locate the optimal feedforward gain is also proposed.

Abstract: This paper make the rigid support Jeffcott shaft-mechanical seal system as the research object. Firstly, it establishes the equivalent stiffness matrix and damping matrix of the rotation shaft with mechanical seal in the fixed-coordinate system, then derives the motion equation of the shaft with mechanical seal and applies the numerical simulation method to analyze and gain the vibration characteristics of the rotation shaft with mechanical seal system. Numerical simulation results show that: when the rotation shaft works at the speed of the subcritical speed, the trajectory of centre will change with the speed of the shaft. When the shaft works at the speed of the second supercritical speed, the trajectory of centre will be a limit circle. When the shaft works at the speed of the subcritical speed, the vibration response appear 1X, 2X, 3X and so on component of the vibration, and when Ω is 1/2, 1/3 and so on, 2X, 3X and so on component of vibration is biggest; when the shaft works at the speed of the second supercritical speed, 2X and 2X above component of the vibration is very small, even to zero, and then the trajectory of the centre is a limit circle. When h_min is different, amplitude-frequency diagram of the X direction of the rotation shaft is different. When h_min is bigger ,1X, 2X, 3X component of the vibration is bigger.

Abstract: The development of computers and the internet have made distance learning distribution easier and faster and have given rise to the virtual university, the entire educational offerings of which are conducted online. Distance education is a field of education that focuses on teaching methods and technology with the aim of delivering teaching, often on an individual basis, to students who are not physically present in a traditional educational setting such as a classroom. It has been described as a process to create and provide access to learning when the source of information and the learners are separated by time and distance, or both. How to motivate learning sub-centers to improve education quality has become the focus of the participants’ game. The expansion dynamic tripartite game model was set up and the simulation shows the corresponding results.