Application of Continuum Damage Mechanics in discontinuous crack formation: Forward extrusion chevron

Soyarslan C., TEKKAYA A. E., AKYÜZ U.

ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, vol.88, no.6, pp.436-453, 2008 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 88 Issue: 6
  • Publication Date: 2008
  • Doi Number: 10.1002/zamm.200800013
  • Journal Name: ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.436-453
  • Keywords: fracture mechanisms (formation of central bursts), damage coupled elasto-plasticity, finite strain, finite elements, DUCTILE FRACTURE CRITERIA, METAL-FORMING PROCESSES, FINITE-ELEMENT METHOD, CENTRAL BURSTS, SIMULATION, PREDICTION, STRAINS, MODELS, DEFORMATION, ELASTOPLASTICITY
  • Middle East Technical University Affiliated: Yes

Abstract

Materializing Continuum Damage Mechanics (CDM), numerical modeling of discrete internal cracks, namely central bursts, in direct forward extrusion process is presented. Accordingly, in a thermodynamically consistent setting, a local Lemaitre variant damage model with quasi-unilateral evolution is coupled with hyperelastic-plasticity. The formulations are constructed in the principal axes where simultaneous local integration schemes are efficiently developed. To this end, the framework is implemented as ABAQUS/VUMAT subroutine to be used in an explicit FE solution scheme, and utilized in direct forward extrusion simulations for bearing steel, 100Cr6. Discontinuous cracks are obtained with the element deletion procedure, where the elements reaching the critical damage value are removed from the mesh. The periodicity of the cracks shows well accordance with the experimental facts. The investigations reveal that, application of the quasi-unilateral conditions together with the crack closure parameter has an indispensable effect on the damage accumulation zones by determining their internal or superficial character. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.