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Mg합금의 디지털 카메라 케이스 개발을 위한 성형해석에 대한 연구
정동원(D. W. Jung) 한국소성가공학회 2010 한국소성가공학회 학술대회 논문집 Vol.2010 No.10
The characteristic of magnesium alloy is the most light in utility metal, the effect of electromagnetic wave interception excellent specific strength and absorptiveness of vibration. Although magnesium alloy with above characteristic is i subject matter which is suitable in world-wide tendency of electrical component frame, sheet magnesium alloy is difficult to process. Therefore, forming analysis of sheet magnesium alloy and applying warm-working to process an indispensable. Among Finite element method, the static implicit finite element method is applied effectively to analyze sheet magnesium alloy stamping process, which include the forming stage. In this study, it was focused on the crack wrinkling and spring back on sheet magnesium alloy stamping by the static implicit analysis. According to this study, th: result of simulation will give engineers good information to access the forming technique on sheet magnesium alloy. Am its application is being increased especially in the production of electrical component frame for the cost reduction, saving of defective ratio, and improvement of Productivity.
정동원(D. W. Jung),김봉천(B. C. Kim),김동홍(D. H. Kim) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.5
The purpose of this study is to evaluate the influence of the scatter in mechanical properties and stamping process parameters on an industrial sheet metal forming process. Based on a previously optimized forming process, a robustness analysis has been performed. The robustness analysis clearly showed production problems for the part not initially revealed by the analysis of the process that was trimmed for “optimality”. The sensitivity of the results on the variation of the parameters was evaluated. It was shown that all parts of the sheet do not react equally sensitively to the variation of the input. Zones of critical response could be identified in accordance with the zones on the actual part that showed failure in mass production. The results reveal that the common practice of performing evaluations with fixed safety margins is non-effective and hence very dangerous, or is extremely conservative and thus costly. The application of stochastic simulation methods reduces the need for wide safety margins while simultaneously increasing the reliability of the process by incorporating uncertainty into the simulation.
정원지(W. J. Chung),송태진(T. J. Song),정동원(D. W. Jung),방덕제(D. J. Bang),윤영민(Y. M. Yoon),김기현(K. H. Kim) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월
This research is that analyze multi-body system that have flexibility. We composed system consisted of crane, part of traveling and robot. And we analyzed the aspect of vibration when this system runs using ADAMS. Through this research we can analyze vibration and displacement of end-effect pill of the large size robot. And this research can become reference that is going to analyze resemblant dynamic system.
One-Step Forming을 이용한 박판성형 해석에 관한 연구
정동원(D. W. Jung),이상제(S. J. Lee),김광희(K. H. Kim) 한국해양공학회 1999 韓國海洋工學會誌 Vol.13 No.2
The objective of this paper is to introduce very fast but still stable solution using finite element procedures, and it has been used in an iterative mode for product design applications. A lot of numerical techniques have been developed to deal with the material, geometric and boundary condition non-linearities occurred in the stamping process. One of them, the One-Step FEM is very efficient and useful tool for a design and trouble-shooting in various stamping processes. In this method, the material is assumed to deform directly from the initial flat blank to the final configuration without any intermediate steps. The formulation is based on the deformation theory of plasticity and the upper bound theorem. As a result of the calculations, the initial blank shape is obtained, together with the material flow, strains and thickness distribution in the part.
정동원(D. W. Jung),김봉천(B. C. Kim),김동홍(D. H. Kim) 한국소성가공학회 2012 한국소성가공학회 학술대회 논문집 Vol.2012 No.5
In this study, roll-bending process was proposed to manufacture the door panel produce using pre-coated material. In order to obtain desired curvature radius and wall angle of final product, finite element method (FEM) was adopted to predict die radiuses and bending angles. First, combined kinematic/isotropic hardening law with new way to determine material parameters in tension/compression tests was applied to predict stress strain curves at various pre-strain. This hardening model was then investigated for roll-bending spring-back prediction. To verify the effects of die radius and bending angle on the curvature radius and wall angle, several values of them were changed to simulate and predict roll products after spring-back.