재료의 특징에 따른 국부화에 대한 수치해석적 연구

A Study of Localization with Material Properties Using Numerical Method

  • 황두순 (충남대학교 기계공학과 대학원) ;
  • 이병섭 (충남대학교 기계공학과 대학원) ;
  • 이용성 (충남대학교 기계공학과 대학원) ;
  • 윤수진 (국방과학연구소) ;
  • 홍성인 (충남대학교 기계공학과)
  • 발행 : 2000.08.01

초록

Formation of Shear Band under the adiabatic condition is widely observed In the engineering materials during rapidly forming process lot a thermally rate-dependent material. The shear band stems from evolution of a narrow region in which an intensive plastic flow occurs. The shear band often plays a role of a precursor of the ductile fracture during a forming process. The objective of this study is to investigate the localization behavior using numerical method. In this work, the implicit finite difference scheme is employed due to the ease of convergence and the numerical stability It is noted that physical and mechanical properties of materials determine how the shear band is formed and then localized. Material properties can be characterized with inertia number dissipation number and diffusion number. It is observed that the dimensionless numbers effect on localization. Using a parametric study, comparison was made between CRS-1018 steel with WHA (tungsten heavy alloy). The deformation behavior of material in this study include an isotropic hardening as well as thermal softening. Moreover, this study suggests that a kinematic hardening constitutive relation be required to predict a more accurate strain level at a shear band.

키워드

참고문헌

  1. J.appl.Phys. v.15 Effect of strain rate upon plastic flow of steel C. Zener;J.H. Hollomon
  2. J. Mech. Phys. Solids v.36 no.3 An Experimental Study of the Formation Process of Adiabatic Shear Bands in A Structural Steel A. Marchand;J. Duffy
  3. Int.J.Plasticity An Energy Based Localization Theory : 1. Basic Framework, 2.Effects on the Diffusion, Inertia and Dissipation numbers H.P.Cherukuri;T.G.Shawki
  4. Int.J.Impact Eng. v.8 no.2 Adiabatic Shear Morphology at Very High Strain Rates C.Fressengeas
  5. 대한기계학회논문집 v.18 no.5 4340 강의 단열 전단 밴드 생성에 대한 유한요소 해석 및 실험적 고찰 정동택;유요한
  6. 한국소성가공학회 '99년도 춘계학술대회 논문집 단열전단밴드의 국부화 진행에 대한 수치해석적 연구 황두순;이병섭;윤수진;홍성인
  7. 한국소성가공학회지 v.8 no.4 업셋 단조의 좌굴 및 소성 불안정 유동에 관한 연구 김완수;이병섭;황두순;홍성인
  8. 한국소성가공학회 '99년도 춘계학술대회 논문집 이동 경화를 고려한 좌굴 및 소성 불안정 유동에 관한 연구 이병섭;황두순;윤수진;홍성인
  9. J.Mech.Phys.Solids v.30 no.2 Modeling of Adiabatic Shear Band Development from Small Imperfections A.M.Merzer
  10. Arch.Mech. v.40 The plastic spin concept and the theory of finite plastic deformation with in-duced anisotropy R.B.Pechersk
  11. J. App. Mech. v.50 Corotational Rates for Kine-matic Hardening at Large Plastic Deformation Y.F.Dafalis
  12. Int.J.Plasticity v.3 On the Application of the Plastic Spin Concept for the Description of Anisotropic Hardening in Finite Deformation Plasticity J.E.Paulun;R.Pecherski