Applied Mechanics and Materials Vols. 16-19

Abstract: The unconstrained optimization model applying to radial deviation measurement is established for assessing coaxality errors by the positioned minimum zone method. The properties of the objective function in the optimization model are thoroughly researched. On the basis of the modern theory of convex functions, it is strictly proved that the objective function is a continuous and non-differentiable and convex function defined on the four-dimensional Euclidean space R4. Therefore, the global minimal value of the objective function is unique and any of its minimal point must be its global minimal point. Thus, any existing optimization algorithm, as long as it is convergent, can be used to solve the objective function to get the wanted values of coaxality errors by the positioned minimum zone assessment. An example is given to verify the theoretical results presented.

Abstract: Multi-point forming (MPF) is a flexible manufacturing technique, which is made up of a set of adjustable base elements controlled by MPF-CAD/CAM software. It uses discrete punches to express a continuous 3-D surface, by which the work piece’s surface under manufacturing is formed. In this paper, to investigate the feasibility of the multi-point forming for the tailor-welded blank ( TWB ), the explicit finite element model for TWB in MPF is established, then spherical surface TWB is selected as an example to analyse reason for generation of weld joint offset defect, and finally method to suppress generation of defect is proposed. The results show that in MPF for spherical surface part, weld joint removes to thick blank direction in zone of expanding and suspending, but to think blank in zone of blank holder; weld joint offset can be controlled effectively by adopting stepped blank holder and applying proper blank holder force .

Abstract: In this article, a new concept named ‘Closed-loop Manufacturing System’ (CLMS) is introduced. The Workpiece Machining Precision PID Control Model (WMPPCM) is proposed and described. PID error compensation model expressions are structured. The experimental method of WMPPCM is established. In the experiment, WMPPCM could be utilized to estimate the trend of machining error so as to conduct the adjustment before production. The experiment has verified the feasibility and validity of WMPPCM. The experiments have also proved that WMPPCM can decrease machining error more effectively then traditional CNC machining method.

Abstract: Based on development project of electro-mechanical control type continuously variable transmission, this paper has done the following works: First of all, the structure and working principle of EM-CVT is studied; then, mathematical model was established; finally, via numerical simulation, Performance Parameters of transmission system, such as mechanical characteristics, dynamic performance of execution system are mastered in the transmission process of EM-CVT. Analysis of the study will contribute to the development of high-quality and highly efficient controller for EM-CVT.

Abstract: Controlled five-bar is an important area of contemporary mechanism. On account of the current gap in design software about five-bar, a controlled five-bar design platform (CFDP) has been developed with VC++ and OpenGL based on the theory of five-bar. The platform has two main functions of motion analysis and path synthesis, therefore offers a great convenience for the designers. This paper introduces the method of path synthesis and motion analysis, and then the functions and structures of the platform are discussed. Conclusion gives the overall attitudes on the software.

Abstract: The concept and content of project management in the networked collaborative design system is presented according to the mechanical product design typical process and its state-of-the-art requirement. The key technologies of the collaborative project management are studied mainly, the Fuzzy Analytic Hierarchy Process (F-AHP) algorithm is employed to select collaborative partners, the method of Design Structure Matrix (DSM) is put forward in process of decomposing and assigning design tasks, and the weight-coefficient recursively statistic algorithm is used in controlling task schedule. The implementing technologies of the 3D networked collaborative design system oriented project management are researched simultaneously, such as collaborative data communication, conversation tool and design tool. The archetypal system platform was developed, it's proved that the 3D collaborative design system is qualified for complex mechanical product collaborative design by synergic team.

Abstract: In the paper, a micro-EDM prototype was designed, and a preliminary machining experiment was done. The micro-EDM prototype was makeup by three dimensions stage, transistor type isopulse generator with pulse duration of 80ns, and environment maintain system. The machining experiment approved that the prototype in good working order, the stage can reach very high precision, and simple micro-EDM machining was done.

Abstract: The V-cone flow meter is widely used to measure gas, liquid and high temperature steam in current industrial production. By applying the FLUENT software of CFD, a three-dimensional model about the V-cone flow meter is built. The effect of technical parameters on flow in the V-cone flow meter field has been studied by using computational fluid dynamics (CFD). The data fitting for empirical formula of the outflow coefficient was completed by using MATLAB software to provide some basis for the further production and exploration. The simulation outflow coefficient is relevant to the parameter of the effective diameter ratio , the diameter of pipe D, front-cone angle and back-cone angle .

Abstract: The backup roll of the strip rolling mill is a key component of the steel rolling production line, so the research to reduce the consumption of it has become an important issue. The roll can’t achieve the technology requirements because of the repeatedly abrasion and regrinding. At present, weld repaisleeve is the mainly solution, but it is not very satisfaction as the complex technologies and plenty of equipments. In this paper, a kind of big internal cooled backup roll with numbers of sleeves assembled together was brought up. The roll core can be reused. Numbers of sleeves assembled together can reduce the height compare with a single one; it can be mass produced by sleeve rolling machine. Therefore it can significantly reduce the costs of production.

Abstract: According to the standard GB/T13799-92 of People’s Republic of China, the reliability design for the double circular-arc cylindrical gear transmission is completed by applying limit state theory. Weibull distribution is used to describe random factors in the design. A computer applied program is developed based on VC++ platform to achieve the computer-aided reliability design of circular-arc gear, and get the reliability information of the designed gear quickly and accurately.