A Parametric Study on the Springback Considering the Stress Variability in Explicit Finite Element Analysis

외연적 유한요소해석에서의 응력 변동성을 고려한 스프링백 영향 인자 연구

  • 이경돈 (고등기술연구원) ;
  • 권재욱 (고등기술연구원) ;
  • 전병희 (인덕대학교 기계설계과) ;
  • 김성종 (강원대학교 기계 메카트로닉스 공학부) ;
  • 김형종 (강원대학교 기계 메카트로닉스 공학부)
  • Published : 2000.10.01

Abstract

It is desirable to predict springback quantitatively and accurately for the tool and process design in sheet stamping operations, however, it is blown very difficult. The result of springback analysis by the finite element method is sensitively influenced by numerical factors such as blank element size, number of integration point, punch velocity, contact algorithm etc. In the present work, a parametric study by Taguchi method is performed in order to evaluate the influence of numerical factors on springback Quantitatively and to obtain the combination of numerical factors which yields the best approximation to experimental data. Since springback is determined by the residual stress after forming process, it is important to evaluate stress distribution accurately. The oscillation in the time history curve of stress obtained by explicit FEM says that the stress solution at termination time is in very unstable state. Therefore, a variability study is also carried out in this study in order to assess the stability of implicit springback analysis starting from the stress solution by explicit forming simulation. The 2D draw bending process, one of the NUMISHEET '93 benchmark problems, is adopted as an application model.

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