Transactions of the Korean Society of Mechanical Engineers A (대한기계학회논문집A)

The Korean Society of Mechanical Engineers (대한기계학회)
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Identification of the Bulk Behavior of Coatings by Nanoindentation Test and FE-Simulation and Its Application to Forming Analysis of the Coated Steel Sheet

나노인덴테이션 시험과 유한요소해석을 이용한 자동차 도금 강판의 도금층 체적 거동결정 및 성형해석 적용

  • 이정민 (부산대학교 대학원 정밀기계공학과) ;
  • 이경수 (부산대학교 대학원 정밀기계공학과) ;
  • 고대철 (부산대학교 ILIC) ;
  • 김병민 (부산대학교 기계공학부)
  • Published : 2006.11.01
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Abstract

Coating layers on a coated sheet steel frequently affect distributions of strain rate of sheets and deteriorate the frictional characteristics between sheets and tools in sheet metal forming. Thus, it is important to identify the deformation behavior of these coatings to ensure the success of the sheet forming operation. In this study, the technique using nano-indentation test, FE-simulation and Artificial Neural Network(ANN) were proposed to determine the power law stress-strain behavior of coating layer and the power law behavior of extracted coating layers was examined using FE-simulation of drawing and nano-indentation process. Also, deep drawing test was performed to estimate the formability and frictional characteristic of coated sheet, which was calculated using the linear relationship between drawing force and blank holding force obtained from the deep drawing test. FE-simulations of the drawing process were respectively carried out for single-behavior FE-model having one stress-strain behavior and for layer-behavior FE-model which consist of coating and substrate separately. The results of simulations showed that layer-behavior model can predict drawing forces with more accuracy in comparison with single-behavior model. Also, mean friction coefficients used in FE-simulation signify the value that can occur maximum drawing force in a drawing test.

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References

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